Glossary A-G

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Glossary A-G

Messaggioda Aldebaran » 30/01/2011, 11:16

Definitions Explained
STEEL Plant for the production and processing of steel. The steel mills that use liquid iron are defined at full cycle and differ from those plants that melt scrap with electric furnaces.
Alloy steel, iron and carbon with a carbon content less than 1, 8%, which may acquire, heat treatment, specific physical characteristics.
STEEL CONTROLLED SULFUR risolforato as steel but with the percentage of sulfur from 0020 to 0040. Sulfur acts as a marked embrittling effect that manifests itself in the shear rupture and to facilitate the detachment of the chip. Eg C45R with specified range of variation of S content% from 0020 to 0040 or C45E with a maximum sulfur content specified 0035%
CARBON STEEL iron-carbon alloy with a content of less than 1.8% C that can hold up to 1.6% manganese and traces of other elements.
STEEL HARMONIC alloy of iron and carbon with the addition of silicon and manganese, which has elasticity and strength. E 'used for the construction of springs.
STEEL BASE NOT
LEGATO steels for which there is no required quality prescription involving special precautions during the production process. (EN 10020)
STEEL QUALITY
LEGATO steels whose use is similar to that of non-alloy steel grades, which contain the alloying elements that make them classified as alloy steel. (EN 10020)
QUALITY ALLOY STEEL NOT steels which, in general, does not require any regularity of response to heat treatment and no limitation on the purity against non-metallic inclusions. (EN 10020)
STEEL eutectoidic steels with a carbon content equal to 0.83%
Iron-carbon stainless steel alloy containing at least 12% of chromium that imparts resistance to oxidation and corrosion.
STEEL hypereutectoid Steels with carbon content over 0.83% and up to 2.06%
STEEL IPOEUTETTOIDE steels with a carbon content <0.83%
ALLOY STEEL iron-carbon alloy that contains other added elements such as chromium, manganese, nickel, molybdenum, vanadium, tungsten, cobalt and so on.
LIQUID STEEL In statistics up to a stainless steel liquid ready for casting, as it comes directly from the fusion of raw materials or scrap.
Maraging steel, steel with high ductility, high yield, good hardenability, good weldability. In the heat treatment is not sensitive to deformation and to decarburization. It has good resistance to low temperatures. Is hardened with a simple aging at 400-500 ° C (from martensite-aging), which raises the hardness and the breaking point. Before machining is to be dissolved. Applications: molds, die casting parts and components.
STEEL RISOLFORATO are steel with a percentage of (S) Sulphur%> 0.10 (high sulfur). This element is introduced intentionally in the process of casting in order to improve machinability.
SPECIAL STEEL
LEGATO steels for which precise control of chemical composition and the particular conditions of preparation and giving them the control over various properties forming ed'attitudine use in combination and within narrow limits. (EN 10020)
SPECIAL ALLOY STEEL NOT Steels that, as compared with high-quality steels, a higher purity, particularly in respect of non-metallic inclusions. In most cases they are intended for treatment of reclamation. (EN 10020)
SUPER CLEAN STEEL Steel super clean in terms of inclusions.
Stainless Steel SUPERCLINC capable of counteracting the weakness in time. It is used for the manufacture of rotors. The elements Si-Al-Mn are maintained at very low levels.
GROWING crystallization nucleation of atoms on endogenous.
This structure of acicular-shaped pins, needle-like.
ACCESSION bond that comes due to attractive forces, usually of a physical nature, between molecules of different substances.
REFINING Treatment converter which converts, by injection of oxygen, iron steel, reducing the content of carbon, sulfur, phosphorus and silicon.
Refining in order to maximize productivity, when the molten steel has reached the state, is poured in the ladle in order to free up the furnace. In the ladle furnace refining occurs and it is here that the steel takes on the identity of the final analysis, purity and, in most cases, treatment under vacuum to remove gases such as hydrogen, oxygen and nitrogen.
REFINING
STRUCTURAL heat treatment for purposes of refining the grain. It consists of a heating to a temperature slightly above Ac3 (Ac1 for steels hypereutectoid) without spending too long at that temperature, followed by cooling at speeds appropriate.
AGGREGATES The crystals are the way in which atoms are aggregated in solid bodies, commonly referred to as grains.
ALKALI OR ALKALINE name given to the hydroxides of alkali metals group a period of 2 to 7 in the periodic table.
ALLIGATOR fusion of different elements in order to obtain an alloy.
Allotropy (1) phenomenon for which the same substance may have different crystalline forms with different properties. Many elements may be in different forms such as the crystalline state. sulfur α and β sulfur, white phosphorus and red phosphorus, the diamond and graphite. In the crystals have rhombic sulfur is α and β in the monoclinic crystals.
Allotropy (2) Different symmetry of a crystal lattice that occurs in metals according to the temperature taken.
BLAST FURNACE A particular type of furnace refractory brick, reinforced by a metal structure, in which the merger takes place and the reduction of iron ore for the production of cast iron.
MAGNETIC steel which has ferromagnetic behavior can be demagnetized with an appropriate heat treatment which involves passing the critical point of magnetism (770 °), stay above that point for an appropriate period and cooling usually in air or in oven.
AMORPHOUS Substances not have its crystalline form (eg amorphous carbon).
CHEMICAL ANALYSIS set of methods to determine the chemical composition of substances.
ANCHORAGE treatment to facilitate the painting through an amendment to the metal surface, so that it is macroscopically rough, through the formation of a layer
adherent oxide, phosphates or chromates giving a microrugosità able to firmly anchor the paint that is applied in the next step
ANCHOR MECHANICAL means an anchor between two metallic elements through the contribution of metal flanges, nuts and bolts, welds etc..
Amphoteric is said of a body capable of combining with acids and bases (bases: a substance capable of binding hydrogen ions of an acid).
ANISOTROPY The shape of a crystal is different in different directions, and are also different physical properties (refractive index, electrical conductivity, thermal conductivity, mechanical properties, etc...) which vary depending on the direction in question.
ANODIZING Anodizing is an electrolytic passivation process used to increase the thickness of natural oxide layer on the surface of metal parts. Anodizing increases corrosion resistance and wear resistance. Anodic films are applied to protect aluminum alloys, titanium, zinc, magnesium and niobium. The anodizing is not useful for carbon steel because these metals form oxide bad for this treatment.
Warmth electricity supplied from the torch (plasma torch: device drive electricity into thermal energy given to a gas passing through a plasma) to the workpiece.
Ambient atmosphere in which the metal to be treated is heated to the process produttivo.Atmosfere details are used to protect the metal surface, or to change the chemical composition of the elements on the surface, so as to add or remove carbon, nitrogen, hydrogen, and add some elements such as chromium, silicon, etc..
ATMOSPHERE ENDOTHERMIC atmosphere oven with a controlled carbon potential.
EXOTHERMIC ATMOSPHERE Atmosphere furnace exothermically produced and controlled in such a way that does not oxidize the material.
ATOM The smallest fraction of material that can enter into combination and which retains the chemical characteristics of individual items.
AUSTEN solid solution of cementite (Fe3C) g in the iron, and non-magnetic and has excellent resistance to corrosion. Its formation begins when warming up, it exceeds the Ac1 point and is the starting structure for heat treatment quality (usually normalization and rehabilitation). Its formation begins when warming up, it exceeds the Ac1 point and is its very high hardness and considerable hardening tendency during processing to make shaving difficult.
Austenite Austenite that there has not been processed at room temperature after treatment of hardening by tempering.
Austenitizing Training dell'austenite by heating a ferrous alloy in the range of transformation (partial austenitizing) or above the range of processing (complete austenitizing). Without additional guidance, the term refers all'austenitizzazione complete.
AUTO HARDENING cooling by thermal conduction to the unheated parts.
Self-hardening steels whose hardenability is such that an air cooling, a martensitic structure may be given to manufactures.
ACTION LEAGUE When all the elements of a steel, there are two or more alloying elements, in general their action is not the sum total of the actions performed by each element.
WETTABILITY 'term often used in welding to express the content of alloying metals in the carbide that are able to absorb the sealing and to ensure a strong connection.
Salt baths are composed of a molten salt or mixture of molten salts that are more than half liquid at high temperature where the material is immersed. It has a heating rate higher than the air, greater precision and uniformity of heating and protection against oxidation and decarburization.
BATH TIME Massa liquid steel inside the furnace.
BAINE structural constituents formed by acicular cementite in a ferrite matrix with a hardness between 30 HRC and 55 at intermediate cooling rate the carbon diffusion is still possible and the cementite formed yet. Through movements "snap", due to atomic exchange, the resulting structure is called bainite.
Alignments of microsegregation banding (C, Mn, P, ..), parallel to the direction of plastic deformation. Can be deformed during heat treatment. This structure makes it difficult machining operations.
BORING Removal of material by boring bar, the inner diameter of sleeve or cylinder with a hole or blind.
GRAVITY HEAT Zone last to solidify where focus more impurities. In ingots with sprue is the head that will be cut to remove the contaminated part.
BILLET semi-section generally square with rounded edges, obtained by continuous casting.
Standard sizes from 40 to 220 mm.
TRACK composed of two elements.
Running a bevelled chamfer.
BEVEL bevel edge (normally performed on the end of the bars) obtained by a cut angle 45 ° - 35 ° etc..
BLUM Semifinished generally square with rounded corners from the blooming mill ingot or continuously cast directly. Standard sizes from 220 to 400 mm.
COIL (COIL) roll rolled coiled ordered.
Bonderizing applied to the surface of a metal prior to drawing, a solution of zinc phosphate and subsequent soaping in order to reduce friction.
RECLAMATION Heat treatment consists of a sequence of quenching followed by tempering.
Hot rolled product rolled and wrapped in bundles, in general, with nominal sizes from 15 mm to 52 mm.
Borides thermochemical treatment to which a product undergoes iron, and has the purpose of obtaining a state of boride hard and wear resistant surface.
Borides are advanced ceramic materials such as titanium boride, tungsten boride, magnesium boride ...
SLABS semi-rectangular cross-section produced by continuous casting, which will be rolled from the hot strip mill.
BRAZING permanent union of two or more mechanical parts of a particular type of welding. Eg pieces of steel welded together with a brass. It is normally carried out with laser beams that allow precise control of heating of the material base of both parties to merge, and the fusion of the welding wire.
BURN irreversible alteration of the structure and properties caused by the onset of melting interesting the grain boundaries.
BROWNING operation carried out in an oxidizing atmosphere and a suitable temperature so that the polished surface of the product from becoming covered with a thin iron oxide layer adherent dark.
Tumbling surface treatment of metal parts. Equipment are a continuous stream and vibrating devices that allow us to obtain the desired finish. The tumbling is done with mixtures of glass beads, mineral grit, or grit corundum ceramics.
CALENDAR spiral tube forming machine or to give bending sheet metal.
CALEF Phenomenon by which small droplets of liquid can remain on a metal strongly heated. It is also used in heat treatment to indicate the persistence of the vapor phase, or their accession to the surfaces of bubbles of steam that are often the cause of insufficient cooling rate.
KEYING Rigid connection without the possibility of relative motion between two mechanical parts. The technique takes advantage of the thermal expansion at high temperature (eg +300 ° C) or contraction at low temperature (eg -180 ° C with liquid nitrogen) of the steel in order to create a pair immovable.
GAGE measuring instrument of precision used for controlling the size of the details, especially in machine work.
Calming effect of a metal or an alloy, added in the steel liquid, allow to remove dissolved gases. Are V (Vanadium) Al (aluminum), Ti (titanium) Si (silicon), Ca (calcium), etc. ..
Latent heat thermal energy absorbed or released when a substance undergoes a change of state, solid-liquid, vapor and liquid.
SPECIFIC HEAT The amount of heat needed to raise a ° C temp. unit mass unasostanza.
Calorization thermochemical process of carrying the spread of a metal on the surface of another metal, particularly aluminum on the surface of an alloy steel.
Cooling capacity Attitude of a medium (air, oil, polymer, water, salt bath, etc..) Achieve a given cooling program.
THERMAL CAPACITY number of calories that you should give a body to raise its temperature by one degree. In homogeneous bodies is equal to the product of body mass for the specific heat of the substance that constitutes it.
CHARACTERISTICS. MECHANICAL FATT transition temperature at which the area of intergranular fracture is 50% of the original after rupture of several tubes Charpy V-notch They can be used by different temperatures - 180 ° C (liquid nitrogen) up to + 150 ° C and beyond.
Em Energy in burst test, the pendulum impact strength of type Kv - KCU - DVM - Mesnager.
Longitudinal elastic modulus E, which is used by designers to verify the efforts bending under stress, in operation. The value is obtained by tensile test. The closer the value is high, the more rigid structure will fail and the elastic deformation desired.
G modulus of elasticity in torsion, or bypass. To get the value using the formula:
G x E m = E = longitudinal modulus
2 (m +1) m = 1/rapporto Poisson = 3.30
N Force: Newton.
J Energy: Joule.
Voltage ksi: thousands of pounds - force per square inch.
lbf Pound - force.
Rm - R Tensile strength determined by tensile proportional tubes, is expressed in N / mm ²
Stress Rp 0.2 to Rp 0.2% yield is commonly known that is valid in case of dispute, the value is deducted from the tensile test and is expressed in N / mm ². The tensile yield strength ReH instead is normally used for carbon steels.
A% - Elongation. Value deduced from tensile test
C% - Z% contraction at fracture. Value deduced from the tensile test.
KCU Notched, U-shaped tubes proportional to the pendulum routes with significant energy expressed in J.
Notched V-kv
Brinell hardness HB 10/3000 EN 10003, determined on the surface of the material, it is useful to know, approximately, the value of material failure. Ø ball = 10 = 3000 Kgf pressure.
HRC Hardness Rockwell "C" EN 10109, usually given to material strength of 760 N / mm ² to 2420 N / mm ²
HV - Vickers Hardness, normally given to material strength from 1320 N / mm ² to 2500 N / mm ² and above.
CHARACTERIZATION targeted search to identify and highlight the main features of a product.
Indicates the fraction of free carbon in a carbon steel or a cast in the form of graphite.
CARBON TOTAL Total amount of carbon in a ferrous alloy matrix, consisting of the sum of free carbon and carbon steel.
CARBONITRIDING Heat treatment of steel surface that is in the enrichment in carbon and nitrogen atmosphere rich in these elements, in conditions closer to those of cement.
CARBONITRIDING IN BATHROOM
SALT Carbonitriding salt bath containing cyanide.
The carburetion CARBURATION causes an increase in the percentage of carbon in a Fe-C alloy and is obtained by means of chemical and thermal operations.
CARBIDES binary compounds of carbon with other elements, are formed by the union of a metal with carbon at temperatures high enough. The silicon carbide (SiC carborundum) are highly abrasive. For the manufacture of cutting tools using steels with good distribution of carbides of tungsten and titanium (high speed steel).
Torpedo cars special railway wagon lined with refractory bricks which is carried and poured the liquid iron.
CATAPHORESIS phenomenon of migration to the cathode of particles (colloids: epoxy resin or acrylic) suspended in a liquid under the action of an electric field. It 's a surface treatment capable of giving to steel or alloy, good corrosion resistance, it also allows for better adhesion of paint finish.
Unit cell symmetry of the crystal lattice.
HARDENING Adding carbon to the surface of a metal by heating in contact with solid, liquid or gas rich in carbon.
Gas carburizing treatment in a medium-gas environment.
Liquid cement treatment in baths of molten salts.
Treatment in solid concrete half-solid medium, is performed in closed metal boxes (a technique passed)
CEMENT formyl Fe3C iron carbide, the chemical combination of iron and carbon, with the percentage of C = 6.7%. its hardness can be up to 63 HRc. Has ferromagnetic properties below 210 ° C, a crystalline substance is very hard but extremely fragile. With slow cooling, and decomposes into ferrite and graphite or carbon graphite.
It can be:
● when the primary form for direct separation by liquid
● secondary when it separates dall'austenite
● higher education when it separates from the ferrite
The morphological aspect may be: globular and / or ductile iron, lamellar and acicular.
CERTIFICATION document bearing a statement issued by a corporation or an authorized person attesting to the characteristics and quality of a product.
SHEARING cold cutting, machining, sheet, strip, etc..
CYANIDE Carbonitriding performed in a bath of molten salts containing cyanide.
THERMAL CYCLE Evolution of temperature as a function of time.
Cyclotron particle accelerator used to obtain beams of positive ions with high kinetic energy, greater than the value needed to produce nuclear reactions (transmutation, disintegration). Superconducting Cyclotron eg employing a superconducting magnet.
Cleavage in mineralogy is synonymous with the cleavage. Means the fracture due to the propagation of a crack through a low index crystallographic planes of sliding. In the steel, the fracture cuts the grain boundaries and this is also called "brittle transgranular"
COALESCENCE geometric evolution of a precipitate particle (see precipitation) by diffusion through the matrix of elements, from small particles (disappear) into the larger (the volume increases).
Coercivity 'When referring to the materials is defined under cercitiva the magnetizing force that must be applied to a magnetic material in a direction opposite to the induction remaining in order to reduce the induction to zero. The coercivity is measured and then in A / m in Oersted, Gauss, etc..
COKING PLANTS plant dry distillation of coal or fossil fuels for cooking in the preparation of coke. The coal may be subjected to screening as well as the operation, also on the grind. The coal in the cells is heated in combustion chambers which transmit the heat through the wall of refractory material at higher temperature corresponding to a lower distillation time and vice versa. The heating is by combustion of coke oven gas or gas mixed with blast furnace gas, coke oven
CASTING Together steel or cast iron produced in a series of operations in the oven or nell'altoforno. The term is also used to refer to all of the products from the same chemical composition.
CASTING operation by which the liquid steel passes from the ladle to the mold.
CASTING Together steel or cast iron produced in a series of operations in the oven or nell'altoforno. The term is also used to refer to all of the products from the same chemical composition.
White layer surface layer of thickness 35 - 40 micron which is formed by nitriding. Usually consists of only nitrides crystallize tetragonal.
COMPARATOR tool for very precise measurements. With its use can be determined: flatness, roundness, circularity, etc.. may be proximate or thousandth.
CHEMICAL Defines the type of material and the percentage amount of the components of a product.
Intermetallic compounds chemical compound with a specific crystalline structure, formed by joining two or more metals in various ratios. (Eg bronze in the union of copper and tin).
Concretions Part of different composition (eg a rock stalactite) from the rest of the training or harder consistency, which has grown by providing progressive material.
PACKAGING treatment to eliminate the surface defects of semi-finished steel for final processing before the trial. The operation consists in grinding or torching.
CONDUCTIVITY properties of materials to transmit heat, sound energy or electricity. Its physical size is the inverse of resistivity.
Thermal conductivity when the two ends of a body are kept at different temperatures, there is the passage of energy as heat, motion and without gross alteration of the body, including the hottest and the most extreme cold.
ORDER CONFIRMATION A document that controls the supply relationship. Contents: description of goods, terms and conditions of sale and prevalence verbal agreements and / or inquiries.
Destructive testing checks that involve the destruction of part of the building (strength, resilience, etc...)
NON-DESTRUCTIVE Checks on the material undergoes the same without destruction or damage (ultrasound, Magnetic particle, dye penetrant, etc...) The non-destructive tests include various methods to check to see if there are irregularities in the products produced without damaging the form or characteristics. The most common are visual inspection, liquid penetrant (PT), ultrasonic (UT), radiographic testing (RT), electromagnetic testing (ET)
Radiographic The operating principle is based on the variation of electromagnetic radiation undergo deterioration when they find a flaw in their path inside the material. X-rays can be controlled with maximum thickness of 60 mm while the gamma rays γ reaches 180 mm max.
Specific controls are all those controls to be agreed at time of bid or order. Chemical analysis of flow control can be considered a non-specific but that product is a specific control. Other specific controls are mechanical testing, hardness, decarburization, non-metallic inclusions, non-destructive, wheat, Jominy, fold etc..
CONTROL penetrant method that surface defects using the law of capillary action. A liquid (red) penetrates into the thin cracks, polishing, and follows another liquid (white detector) shows the defects.
Magnetic particle examination The principle is based on the distortion of the force lines that run through a magnetized body when there is a discontinuity that interrupts their journey. In the area of the crack you create two magnetic poles that attract the colored magnetic particles that show the defect.
Ultrasonic technique mainly used for the detection of internal defects, but also the use of ultrasonic probes for external defects. The principle is based on the propagation of sound waves in solids and liquids. Special probes transmit and receive a beam of waves that pass through the artifacts, when they encounter a discontinuity, reflecting a signal that appears on the device and is interpreted / evaluated by the operators.
CORROSION consisting of the chemical and physical phenomena take place on metallic materials by external agents.
Intergranular corrosion Corrosion that occurs preferably at the grain boundary, usually with a negligible or no attack of the adjacent grains.
CONSTITUENT single phase or a mixture of several phases that appears as an individual component in the course of metallographic structure.
COVALENT chemical bond in which two atoms are joined together by placing both of the electrons.
GRAIN GROWTH The growth of grains at the expense of others, implies an overall increase in the average size of the grains that make up the artifact.
Clique microscopic or macroscopic discontinuity of a metal in which two dimensions are far more important than the third (length-width-depth). The presence of this discontinuity in an artifact called the apex of the crack implies the increase in local stresses.
Clique intergranular cracks or fractures that occurs between the grains or crystals in a polycrystalline aggregate.
Clique transgranular cracks or fractures which takes place through the grains.
CRYOGENIC said steel related to their use in the production of cold.
CRYSTAL regular three-dimensional structures formed by a succession of elementary cells, each containing an equal distribution of atoms and ions.
CRYSTALLIZATION Action to crystallize. Is accomplished by fusion, by solution and evaporation, heat and cooling for solution.
CHROMATIC passivation of the surfaces, obtained by a bath.
CHROME galvanic coating application to deposit, ground bars, a film of high hardness of chromium. This treatment confers resistance to abrasion and corrosion, results in a lower coefficient of friction pairs in the mobile and in particular with the rubber seals.
Chromizing thermochemical treatment in order to obtain a surface enrichment of chromium.
CHROME HEXAVALENT chemical element with the value 6, highly carcinogenic, is expressed with Cr 6 +. It can also be bivalent and trivalent Cr 2 + Cr 3 +
RAW This material is not annealed, the rule of natural transformation (drawn, rolled, forged).
HEART inside of a steel the product composition does not change in a thermochemical diffusion treatment.
COOLING CURVE A curve that shows the relationship between time and temperature during the cooling of the metal.
CURVE TRANSITION Change values in the impact test specimens obtained by breaking the high and low temperatures, also called FATT (Fracture Appearance Transition Temperature). It can highlight the fragility of the steel and its transition point (sharp decline in ductility or toughness).
DEALLIGAZIONE corrosion that occurs in alloys CuZn (brass), CuAl (aluminum bronzes) and so on.
PICKLING treatment to eliminate the layers of surface oxides formed during hot working. It can be chemical or mechanical.
Decarburization process (usually unintended and undesirable) to remove carbon from the surface of a steel, where it is placed in contact with certain atmospheres, usually at high temperature. Decarburization dramatically reduces fatigue.
DEFECTOMAT Equipment for surface defects on electrically conductive materials. Using the eddy current method detects faults with mainly transverse orientation, while the notes circograph predominantly longitudinal defects.
IRON REMOVERS plates, rods and reels that are used to remove magnetic separation of iron or other material. They are also used to hold objects and ferrous materials along the conveyor belts.
Dimensional deformation affecting the shape and initial size of a product during a heat treatment or heating.
Plastic deformation and 'a kind of permanent deformation created by external forces and the microscopic point of view corresponds to the flow of specific atomic planes. The plastic deformation can be generated either hot or cold.
Compress compress engineering is the ratio of linear length measured after the stress and the initial length of a component.
DEFOSFORARE removal of phosphorus during the preparation of steel.
DEGASSING treatment under vacuum to remove from liquid gases such as hydrogen, oxygen and nitrogen.
DEHYDROGENATION Heat treatment allows the removal of hydrogen occluded in a ferrous product without changing its structure. Is made after an electrolytic coating or after a chemical pickling.
Dendrite crystal structure tree more evident in the casting cooled slowly in the range of solidification. Typical structure in the shape of pine tree whose growth follows directions branched.
DENSITY The ratio of the mass of a body and that of an equal volume of water at 4 ° C.
Operation Hot DESCALING removal of the oxide layer surface of the billets produced by water jet or high pressure air.
DESULPHURISATION treatment aimed at reducing the concentration of sulfur in the steel liquid.
DEUTERIUM Also known as heavy hydrogen. E 'and the stable heavy isotope of hydrogen. Its nucleus contains one proton and one neutron, then its mass is roughly twice that of hydrogen.
BALANCE CHART
(OR STATE) Graphic representation of temperature and composition limits of existence of phases in an alloy under conditions of complete equilibrium
CHART TEMPERING graphical representation of the relationship between the mechanical and the tempering temperature for a certain length of stay.
CHART PROCESSING set of curves time / temperature setting out for each level of temperature, the initial and final moments of transformation dell'austenite in isothermal conditions. Curves are typical of all steel and vary according to chemical analysis and grain size.
Diamagnetic material that is attracted by a magnet
Synthetic diamond is obtained by heating carbon above 2000 ° C and pressure to about 102 Mpa.
Critical diameter diameter of a bar that can be completely quenched with 50% martensite at its center.
EQUIVALENT DIAMETER 1) Diameter of reference for the heat treatment of square or rectangular, for quenching in oil or water. The privacy practices of such correlation diagrams. EN 10083-1 Figure A.1
2) Also used in the jargon of ultrasound to determine the thresholds for registration. The defects are compared with a flat bottom holes (FBH = flat - bottom hole) charged on block samples of various diameters and heights, eg. defects with a diameter of eq. 3 mm max
BROADCASTING Movement of atoms in a lattice for distances greater than interatomic distances.
GRAIN SIZE OF AUSTENITIC It 's the size of a grain size of austenitic steel when heated in the field, it can be revealed by appropriate etching of a section after cooling to room temperature.
Together Dimetra system symmetry trigonal, tetragonal and hexagonal, in which there are two constants and the third parameter equal unequal.
LOCATION linear lattice defect that results from the solidification process. If the framework is called, the dislocations can move in the artifact, and can increase their density, resulting in microscopic processes of plastic deformation and hardening.
DEOXIDATION (1) Removal of oxygen from molten metal bath by means of appropriate fluxes. (2) Sometimes refers to the removal of unwanted elements in addition to oxygen through the introduction of elements or compounds that react with them quickly.
DISSOCIATION rupture of a chemical compound into simpler compounds or elements. One common example is the dissociation of ammonia (NH3) into nitrogen and hydrogen (H + N).
RELAXATION heating at a temperature (600-650 ° C) to reduce tension, followed by slow cooling in furnace to 250-300 ° C in order to minimize the risk of internal and external retraining efforts. For the materials reclaimed are running normally at 50 ° C below the tempering temperature. When performed in furnaces with protective atmosphere eg. with nitrogen, also called relaxing in white.
DOG HOUSE system for soundproofing and the aspiration of the fumes generated during the process of melting scrap in electric furnaces.
Double leather overlay material partially connected to the base material. In the double skin generally there is a preponderance of non-metallic inclusions.
DOUBLE TEMPERING treatment of reclamation performed twice in order to improve the yield strength of steel.
DOUBLE DISCOVERY treatment in which a hardened steel is subjected to two complete cycles of discovery, usually the second at a temperature lower than the first, in order to ensure the completion of the transformation and to promote the stability of the resulting microstructure.
DUAL PHASE sweet or low-alloy structural steels in which, through thermo-mechanical treatment performed in a production line governs the formation of a biphasic structure (fine-grained ferrite and martensite islands). This involves high static strength and fatigue.
HARDNESS properties of solid materials, linked to the strength of interatomic or intermolecular bonds. It is expressed in terms of resistance which opposes the penetration of the material.
Higher secondary hardness hardness developed by some alloy steels when tempered at temperatures.
DUCTILE properties of a metal material to deform plastically without fracturing.
MASS EFFECT Influence of cooling on the volume of the part of the piece itself: the more the mass, the higher the resistance to cooling.
STEEL PROCESSING Name provided to indicate the procedure for processing steel.
LD process the charge consists of molten pig iron from scrap and calcium oxide CaO.
OLP process allows to refine the pig iron containing up to 2% of phosphorus with lime mixed with oxygen insufflation.
LWS process OBM uses the technique and process of the ancient Thomas. S'insuffla pure oxygen through nozzles on the bottom of the drive (see blast furnace).
BOF process traditional basic oxygen furnaces. The removal of P, S, Si and Mn occurs in part by lime.
Process EBT Eccentric Bottom Tapping oven full of scrap from the casting takes place through a hole on the bottom of the vat (bussaggio eccentric) and avoid dragging debris during casting.
Thomas defosforare method designed to process the iron obtained from materials phosphorous.
EAF process modern electric arc furnaces. The charge is usually made of scrap.
Argon Oxygen Decarburization AOD process, a technique similar to VOD only the mixture blown through the porous membranes at the base of the furnace, consists of a mixture of argon and oxygen. The furnace is normally served by an automated loading system alloys and managed by software on which makes the process reproducible.
VIM manufacturing process in a vacuum induction furnace.
VOD Vacuum Oxygen Decarburization process, a technique that allows the "perfection" of steel (usually steel) with reduced carbon content in the minimum values (<0.03%). The removal of carbon takes place by blowing oxygen in the steel liquid.
VAD Vacuum arc degassing process, the process is often combined with VOD, where a deep degassing (hydrogen <1.2 ppm) and is limited to the basicity of the slag.
VDG Process Vacuum Degas, vacuum degassing with argon blowing.
VAR process recast in a vacuum arc furnace.
ESR remelting process electro.
EBR process recast in a vacuum consumable electrode under a bombardment of electrons.
Combined processes VIM + VAR, VIM + ESR, + WIR etc. ASLD.
ELEMENTS hardeners are elements that are added when the steel is in liquid phase and have the ability to increase the hardness as the material passes to the solid phase. Some of these items are: C, Cr, W, Mo, Co, Ni Nb and some rare earth (lanthanide).
Native element is said of the state where you can find in nature as a mineral element.
ELEMENT OR ELEMENTS simple bodies considered as non-decomposable, in the periodic table of elements, these are neatly arranged according to their atomic weight and chemical properties. The atom of any element consists of a number of common particles and the most important feature is the atomic number that represents the position of the nucleus and the number of electrons that surround it. The elements are divided into metals, metalloids and non metals.
EDM Removal of metals by means of electric shock. Hundreds of thousands of strokes per second creates cavities in the metal target with maximum precision. The discharges are regulated by highly sophisticated mechanical and electronic systems. Normally the process of erosion takes place in an insulating liquid and filtered to remove any remaining metal.
ELECTROFORMING Production of mechanical parts by electroplating into a mold, eg on a specific model. dies, molds.
ELECTROLYSIS chemical decomposition. With this procedure, based on the passage of electric current from anode to cathode through a solution of ferrous chloride, it is possible to obtain pure iron.
ELECTRON particles of negligible mass compared to protons and neutrons, having an electric charge, arranged around the nucleus that contains the mass of the atom.
ENDOGENOUS inclusions that form during solidification in the steel example. manganese sulphide.
ENDOTHERMIC Chemistry: it absorbs heat
Activation energy Energy that must be supplied to a system or a portion of the system, that takes place in a particular process. For example: the energy that is needed for an atom in a crystal moves from one location to another (diffusion).
ENERGY AND COHESION 'the energy required to dissociate one mole (mol) of a solid into its constituents (atoms or molecules).
ENERGY IMPACT amount of energy required to fracture a metal, usually measured by Charpy impact tests (Kv). The characteristics of the samples and test conditions greatly influence the values obtained and thus must be specified types (KCU, DVM, etc...)
Enthalpy and 'a state function of a system and expresses the amount of energy that it can exchange with the environment. For example, in a chemical reaction, the enthalpy exchanged by the system consists of heat absorbed or released during the reaction. In a passage of state, as the conversion of a substance from its liquid to the gas, the enthalpy of the system is the latent heat of evaporation.
ENTROPY thermodynamic state function, representing the amount of heat that the system under consideration exchanged.
Deadline for EPOXY resins obtained by condensation and used for the production of paints, adhesives, laminates, adhesives and as matrix for composites with glass fiber and carbon.
It is said EQUIASSICO grain-shaped multi-faceted and not laminated.
An equilibrium thermodynamic system is in equilibrium when the variables that characterize his state does not change over time.
WASTE term often associated with a liquid that has exhausted its function. Eg, quenching oil, chemical baths for pickling etc..
EXOGENOUS inclusions that are trapped in steel and are externally eg. refractory bricks.
EXOTHERMIC Physics: releasing heat
THERMAL EXPANSION increase in size or volume of a material caused by temperature change.
Surfacing EXUDATIVE liquid metal solidified in the crust through cracks and fissures.
EXTRUSION Force, a metallic or plastic continuously through an opening more or less close to half of helical screws or pistons. The equipment used are called extruders.
HETEROGENEITY composed of parts that do not blend into a whole.
EUTECTIC (1) isothermal reversible reaction in which a liquid solution is transformed by cooling into two or more intimately mixed solid solutions. The number of solid phases obtained is equal to the components of the system.
(2) Structure of an alloy consisting of a mixture of solid solutions formed by eutectic reaction.
HEADSTOCK container by drawing tool (shoulders, saddles, wedges) that allows you to adjust the same in order to eliminate distortions, scratches and restore the optimum conditions of use.
Part of the STEP system chemically and physically homogeneous as a whole, perfectly distinguishable and limited by boundaries known.
BETA (β) The solid phase β is formed by reaction between the solid phase alpha (α) and the residual liquid in the process of solidification.
Fatigue breakage that occurs through propagation of a crack has repeatedly called for by loads that induce, individually, macroscopic deformation.
Thermal fatigue fracture caused by the presence of time-varying thermal gradients that result of the efforts in the cyclic structure.
FERRITE pure iron, which appears in the form of polyhedron micrographic analysis of steel, then known as a structure and a composition. It can take two forms: acicular ferrite (needle-like), or free iron obtained directly from the decomposition dell'austenite during cooling, without the simultaneous formation of cementite. The f. is a constituent of very ductile and the phenomenon causes the formation of built-up edge (the chip sticks to the tool and hard to break). Mild steels containing high percentages of ferrite are processed relatively poorly.
Acicular ferrite Ferrite equiassica not strongly substructure that is formed as a result of continuous cooling at a temperature slightly above the range on the formation of upper bainite.
Free iron ferrite obtained directly from the decomposition of austenite ipoeutettoidica (ipoeutettoide) during cooling, without the simultaneous formation of cementite, also referred to as ferrite proeutettoidica.
IRON first element of the triad of the 8th group. It 's a solid light gray malleable and ductile of metals is the most tenacious of normal use and the most abundant among magnetic metals. Has the disadvantage of being attacked by damp containing carbon dioxide and turn into rust, iron oxide hydrate. Specific gravity at 20 ° C = 7.874 g/cm3 Melting point 1536 ° C
IRON α (alpha) stable state of pure iron at a temperature of 911 ° C, its crystal structure is cubic centered.
IRON γ (gamma) stable state of pure iron between 911 and 1392 ° C, its crystal structure is face-centered cubic.
IRON δ (delta) Status of pure iron stable between 1392 ° C and the melting point, its crystal structure is like that of the iron-centered cubic α.
Ferromagnetic material highly susceptible to induced magnetization, the latter may be removed by heating or demagnetizers artifacts above 769 ° C (Curie point).
ROWS arrays of crystals and second straight lines lying on planes parallel to each other.
CHAIN tool for drawing on the calibrated hole through which passes the material to deform cold second predetermined shapes. The chains are made of hard metal produced with the technique of powder or high speed steel with hardened PVD. The angle of entry serves as a guide for the material to be drawn above all is for the supply of lubricant. The angle is the drawing area is where the real strain and are located where the greatest efforts.
Product WIRE full section, constant along its length, obtained by cold drawing and which can be wrapped in cold wound coils ordered or unordered.
It is said fissile materials that undergo fission as a result of slow neutrons, in practice, the fuel of nuclear reactors.
FISSION process in which the nucleus of an atom bombarded by neutrons, it splits into two approximately equal parts.
DARK Material added during melting of a metal to the fluidity of the oxides and the formation of slag.
FORMABILITY Evaluate the ease with which a metal can reach the desired shape by plastic deformation.
Heat resistance is said shaped material at high temperatures (rolled, forged, etc..)
Cold formed is said shaped material at room temperature (drawn, cold-pressed, etc..)
FURNACE ROOM furnace heat treatment. The working chamber can be square or rectangular in a refractory brickwork. The heating is by combustion burners or by electric heaters. Almost all of these muffle furnaces are equipped with air circulation for uniform temperature inside.
Bell furnace oven treatment. In general, it has a circular base with a central speaker that circulates the atmosphere. The mobile camera is called the bell and is superimposed on the base to protect the office.
OVEN kiln heat treatment independent of the bogie hearth room from which can be removed to facilitate loading and unloading.
Pit furnaces for heat treatment furnace chamber vertical, often used for treatments in order to contain the vertical dimensional deformations that occur with treatment horizontally.
Continuous furnace furnace used for heat treatment progresses continuously with the metal that enters on one side and comes out the other.
FURNACE FOR HEAT TREATMENT particular type of furnace heating chambers which are strictly controlled heat in order to give the steel of the technology you want.
Electric ovens
ARCO hearth furnace refractory materials are placed on which to merge. The thermal energy is supplied from the production of electrical arcing between three electrodes and the charge of scrap.
Electric induction furnaces for heat treatment furnace in which heat is produced by the electric current induced in the body to be heated by an induction coil.
MELTING FURNACE system where the system is the fusion of scrap metal or alloy.
ROTARY KILN heat treatment furnace with ring-shaped rotary hearth. Generally they have plugs.
Part of the steel ladle furnace where it is the refining of liquid steel.
PHOSPHATE Application hot or cold on the surface of a metal prior to painting, of an aqueous solution of acid phosphate of heavy metals such as manganese, zinc, etc..
PHOTON neutral particle that propagates in a vacuum at a speed of ~ 300,000 km / s. with an energy that depends on its frequency and with no rest mass.
THE FRAGILITY
DISCOVERY Embrittlement due to the characteristic of high strength steels for tempering temperatures between 200 and 400 ° C. E 'believed to be the result of the combined effect of the precipitation of cementite at grain boundaries of primary austenite (that later transformed into martensite).
FRAILTY 'THE RED In steels rich in sulfur has significant presence of iron sulfide, which melts at 988 ° C (temperature in the field of plastics processing including hot-es. Rolling and forging. This compound, if in quantities greater than 0, 10% creates a liquid film at the grain boundaries and undermines the cohesion of the crystals.
FRACTURE IN BLUE The test consists of breaking a sample preintagliato followed by heating at 300 ° C in a muffle furnace. The structure of the material takes on a bluish tint and the presence of non-metallic inclusions is evidenced by a very clear and brilliant color.
Fracture of ductile fracture characterized by a clear plastic deformation of the metal, and that proceeds by consumption of large amounts of energy.
GRANULAR FRACTURE type of irregular surface produced after the collapse of a metal, characterized by a rough and granular morphology, by contrast to the smooth fibrous morphology. Can be classified into transgranular or intergranular. This type of fracture is frequently called crystalline fracture ".
Fracture of brittle intergranular fracture of a metal in which the fracture occurs between the edges of the grains, or crystals which form the metal.
FRACTURE transgranular fracture that propagates through the grains.
MILLING Modeling of metal components using milling machines.
FORGED Product obtained by hot deformation of metals. The processing is done by presses, hammers, swaging etc..
Fullerene family of molecules formed from carbon atoms linked by covalent bonds (see covalently) discovered in 1985. Constitute the fourth solid structure of carbon, together with graphite, diamond and amorphous carbon.
FUSION Passing a substance from solid to liquid state by the administration of heat.
FUSION IN SLAG Process for the manufacture of special steels. It consists of a recast of steel (in the form of electrodes, usually round ingots) by immersion in a bath of liquid slag. The advantage of this manufacturing process is to improve the health of ingots and internal characteristics of purity. (ESR = Electro-Slag-Remelting)
ROLLING CAGE The cage mill is the set of cylinders and the structure that supports them.
GALVANIC complex surfacing techniques that use electrolysis. See electrolysis.
GEMINA Union, according to precise laws of two or more servings, but differently oriented crystal in order to determine lattice continuity between them.
GETTER volatile metal with the power to absorb neutrons or gas. An absorbing metal is zirconium.
CAST IRON General term for a large family of ferrous alloys for castings in which the carbon content exceeds the solubility (see solvus) of carbon nell'austenite the eutectic temperature. Most of the cast iron contains at least 2% of carbon, more silicon and sulfur, and may or may not contain other alloy elements. Can be divided into cast iron, white iron, malleable iron, ductile iron, cast iron alloys.
White cast iron cast iron solidifies according to the metastable phase diagram, in which the carbon is in bound form as cementite. Can be obtained by reducing the silicon content and on the other elements grafitizzanti, or by increasing the speed of solidification and cooling. Characterized by high fragility, is the starting material for the production of malleable cast irons.
GREY CAST IRON Cast iron that solidifies according to the stable phase diagram, in which carbon occurs in free form as graphite. Can be obtained by increasing the silicon content and on the other elements grafitizzanti or decreasing the solidification rate and cooling.
Alloy cast iron cast iron in which the resistance to corrosion, oxidation, or heat is increased to levels even important, for example, Ni, Cu, Cr.
CAST IRON Cast iron obtained by prolonged annealing of white cast iron. During this process, the decarburization (white heart malleable cast iron) or graphitization (black heart malleable cast iron) or both processes in place to remove at least part of the cementite. The graphite graphite obtained is called tempering. The ferritic or pearlitic malleable cast irons are respectively composed of a mainly ferritic or pearlitic matrix.
CAST IRON Cast iron that, in the molten state, is treated by the addition of magnesium or cerium with the formation of nodular or spheroidal graphite and the resulting increased flexibility.
GHOST - LINE ghost lines. Bands of segregation that are formed in continuous casting and are then elongated in the direction of rolling. These alignments of segregation can affect the mechanical properties of steel products.
JOINT (O grain boundaries) Zone of separation of grains, with irregular symmetry.
Evolution of geometric spheroidized carbide particles, such as cementite lamellae, to the stable spherical shape.
Gradient Term used to describe the ° C / h during ascent or descent in the heat treatment to reach temperatures.
SCRATCHES Mechanical damage on the surface of the artefacts. The defect is caused by friction between the workpiece and parts of machinery used to manufacture.
Graphitization of carbon precipitation in the form of graphite (graphite is the stable phase of carbon under pressure and temperature).
WHEAT individual region in a polycrystalline metal or alloy. We define the crystal grains is phase pure aggregates of crystals with eutectic structure.
The grain size and Ferritic austenitic grain is understood as the average size of crystals or grains of steel to the austenitic state. For ferritic steels, which can not be subjected to the hardening, the grain is called ferrite.
RAW is said to material machined es. rolled in the rough, so rough forging.
Thickness of the great number of grains per unit area.
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Aldebaran
 
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Re: Glossary H-P

Messaggioda Aldebaran » 30/01/2011, 11:39

HYDRATE combination of a simple substance or compound with one or more water molecules.
HYDROGEN (H) chemical element of Group 1 A of the periodic system, the lightest substance known. Its nucleus contains a single proton, around which revolves a single electron.
HYDROLYSIS cleavage reaction of a molecule of water per share, which results in obtaining two or more smaller molecules or ions.
A combination of water with metal oxide hydroxide.
DRAWING operation of cold forming a thin metal plate, tightening implemented by a form of steel or cast iron.
Impurities in a solid foreign atoms are always present in concentrations more or less relevant. A solid "pure" actually contains 1012 impurities per cubic centimeter.
ENGRAVINGS AND PRINTS OF CYLINDERS defects are due to the wear of rolling cylinders or rollers guide wire drawing and may be distributed in defined distances or on uneven length and width of the pieces.
INCLUSIONS Particles of impurities (usually oxides, sulfides, silicates, alumina and the like) that separate from the liquid metal. In some steels the quantity is intentionally kept high in order to improve workability.
Work hardening plastic deformation of a metal at a temperature low enough not to involve the activation of the recrystallization process resulting in increased hardness and mechanical strength.
HARDENING Increased hardness, usually tied to a heating followed by cooling.
SURFACE HARDENING OF A generic term that covers a number of processes applied to ferrous alloys, as a result of which, after quenching, you get a harder surface of the heart of the building. The processes used are carbonitriding, carburizing, induction hardening, flame hardening, nitriding, the nitrocarburizing, the quenching laser etc.
HARDENING IN AIR
OF STEEL A steel martensite can form and develop high hardness when cooled in air from a suitable austenitizing temperature. Typical of hardened steels.
Precipitation Hardening Hardening caused by the precipitation of a constituent from a supersaturated solid solution.
Secondary hardening hardening obtained by passing one or more discoveries which precipitate a compound or give rise to the formation of martensite or bainite starting from 'residual austenite.
Surface hardening treatment of hardening by quenching after heating surface. See also harden the surface.
Embrittlement significant loss of ductility, toughness, or both in a metal.
Embrittlement acid form of embrittlement can be induced in some metals by treatment with acids.
Hydrogen embrittlement Embrittlement introduced to the absorption of hydrogen in steel during solidification is, both during plating operations.
Embrittlement significant corrosion loss of ductility of a metal as a result of corrosive attack, usually intergranular and often not obvious by visual analysis.
Grain growth phenomenon normally caused by high temperatures, much higher than Ac3.
Steel that resists oxidation, the metals and alloys that have the special property of resisting the attack of oxygen, air or high temperatures.
AUSTENITIC STAINLESS steels with chromium and nickel austenitic structure.
Ferritic stainless steels with low carbon and high percentages of chromium. The structure is ferritic and not susceptible to quenching.
Martensitic stainless steels which alter the physical characteristics of martensite by quenching.
Instill process of introduction of a liquid drop by drop of the appropriate composition in the chamber of a heat treatment furnace in controlled atmosphere. Process eg. for gas carburizing.
Blow To introduce a liquid gas in the steel.
That there interatomic or acting between atoms.
Among the intergranular crystals or between the grains. Also called intercrystalline.
Two intermetallic metal elements mixed in a precise ratio which allows "stacking" of the elements of a crystal structure different from the two starting example. CrAl that give resistance to oxidation.
What is intermolecular or that occurs between molecules.
Critical range of temperature range for a given metal, a critical point between upper and lower critical point.
Solidification range temperature range between solidus and liquidus curves in which the metal liquid and solid coexist.
AGING AND 'a structural transformation, usually by precipitation, which occurs in some alloys after cold deformation and after heat treatment (300 ° C). A sovrainvecchiamento obtained at a temperature higher than room temperature results in unwanted changes in times of physical and mechanical properties (increased resistance characteristics with a reduction in toughness and plastic reserves over time). Some gases such as. nitrogen can promote the aging of steel.
Power inverter circuit for converting direct current into alternating drive while the term is usually used to describe the circuits that perform a conversion frequency of the alternating current. The inverters at the level of mechanical engineering are used mainly to control the motor speed.
ION electrically charged particle formed from an atom or group of atoms, which captured or lost one or more electrons.
Isocrates says of periodic motions that take place during the same period. The term is associated with the curves giving the values indicative of the unit load that causes the creep and rupture of 1% after 100,000 hours.
Isoform Existence of two or more substances that have the same crystalline structure to form the solid solution.
ISOTHERMAL is said of a phenomenon that occurs at a constant temperature.
ISOTOPES atomic nuclei that contain the same number (Z) of protons, but differ in the number of neutrons (N). Each chemical element is characterized by its atomic number Z, has more isotopes, which do not differ in chemical properties but in the atomic weight, indicated by the number A = Z + N.
ISOTROPIC body whose physical properties (eg mechanical properties) are identical in all directions.
HYSTERESIS term used to describe the phenomena such that the state of a system also depends on the sequence of its previous states.
See Jominy hardenability test.
PLATE (SHEET) hot-rolled flat products, freeing up the deformation of the sides, supplied in sheets or in the rough rolling, pickling, in most cases a square or rectangular (but also other forms) with a minimum width of 600 mm . the edges are rough-rolling or shearing, flame cutting or blunted. The cold rolling is also made.
HOT ROLLED + AR rough rolling natural state. Steel product obtained by hot deformation of blooms, billets, etc.. plants named in the mills.
Cold-rolled (+ CR) cold rolled. Steel product obtained by cold, by means of rolling mills, hot-rolled products previously.
ROLLING hot or cold plastic deformation of a material, made from the mills.
ROLLING STANDARDISATION rolling process in which the final deformation is carried out in a specific range of temperatures, with slow cooling in still air, able to develop material in a state equivalent to that obtained after a normalization treatment.
LANTHANIDE Generic name of the 15 rare earth elements with atomic numbers 57 to 71, which have chemical characteristics very similar to each other and with those of lanthanum.
Wide flat-rolled plates with thickness from 6 to 60 mm and a width between 150 and 1250 mm.
Manufactured Flats plan width greater than 150 mm and less than or equal to 1250 mm and whose thickness is generally greater than 4 mm, provided always flat (not wrapped)
and that is the subject of special requirements regarding the edges that need to be alive, and the large plate is rolled caldosulle four sides (or passes)
LASER Light Amplification by Stimulated Emission of Radiation. Light amplification by stimulated emission of radiation. The operation is based on a flash that emits radiation in a gas tube containing appropriate atoms (ruby - Neodymium) that amplify the point of obtaining a highly concentrated and Mono.
Ledebur Aggregation (see pooled data) of crystals of solid phases of austenite and cementite structure in a "zebra."
LEAGUE Substance metallic properties and is composed of several chemical elements one of which is a metal.
League binary alloy that contains only two components.
Max strain fatigue limit at which a metal can be subjected to cycle for a virtually infinite number of cycles.
TENSILE maximum stress a metal can withstand without having residual deformations once the stress is removed completely.
MOULD container in which liquid steel solidifies.
INGOT mass of metal or alloy produced by casting in a mold (mold) for subsequent plastics processing.
LIQUAZIONE phenomena that occur during solidification of alloys formed by fusing elements very differently.
Liquidmetal is not a liquid metal (eg mercury) but is an alloy made of platinum, copper, nickel and phosphorus. It looks like polished glass, has characteristics (strength, hardness, strength, elastic limit, corrosion resistance and wear resistance) than steel. The atomic structure is amorphous and therefore is not limited in performance spring and shock resistance as are the metal crystalline structure. These alloys are well suited to casting technologies for complex forms.
LIQUIDUS It is said of an alloy is completely liquid.
Loppa blast furnace slag containing mainly phosphates, silicates and oxides of iron, calcium, magnesium, etc..
LOT OF SUPPLY Amount of steel products of the same type, same cast, the same size ordered with the same requirements.
MAGLIO machine for hot deformation of steel by the use of a ram.
This residual magnetism phenomenon, quite common in the steel, may create some problems not so much in the workability, but more in the surface finishes. Often, during the grinding or lapping, filing fine remains attracted to the magnetized metal to overheating or excessive removal of material (cutting saw, grinding etc..), Giving rise to poor sanding. The problem can be overcome using degaussing, or by performing a stress relieving treatment before completing the processing.
Magnetostriction is defined as "Magnetostriction" the properties of ferromagnetic materials to change their dimensions when subjected to magnetic fields.
MALLEABLE Moldable, malleable and ductile.
MALLEABILIZZAZIONE heat treatment for the purpose of transforming the structure of a white cast iron to obtain a malleable iron, or by decarburization, or by graphitization of cementite.
MANIPULATOR Automatic (slide horizontally on rails) or free guided by trained personnel who assist the handling of ingots and semifinished products during forging.
MAINTENANCE (TEMPERATURE) Part of the heat cycle during which the temperature of the building is maintained at a constant value (temperature regime) and for a certain time (holding time).
MARKING All products must be identified. Semi-finished products, bars and profiles larger than 35 mm by: paint, labels, pens with engraving or punching power. Products in bars and profiles smaller than 35 mm, by label or by a method listed above. Wire rod: a label attached to the roll. The minimum identification must include: name of the manufacturer, designation of steel, no casting and in the presence of specific checks an identification number that allows you to associate the products to the test certificate.
Martempering E 'a form of interrupted quenching in which the steel is rapidly cooled from austenitizing temperature to a temperature slightly higher than Ms, held at that temperature until the same is not uniform throughout the artifact, and then cooled in still air.
MARTENS product processing extremely hard and brittle, which is formed during very rapid cooling of steel from its austenitizing temperature to a temperature below Mf (martensite finish, usually room temperature). The martensite structure is better and more present in the hardened alloy steel. The temperature at which, during cooling, the transformation dell'austenite in martensite (martensite start) can be determined by empirical formulas. The martensitic transformation is characterized by an expansion of steel and may lead to tensions that produce tears (internal cracks).
MASS amount of solid or heterogeneous or homogeneous fluid together to form a compact whole. Can be: nominal mass, measured mass and theoretical mass.
COMPOSITE type material characterized by a non-uniform, consisting of the two or more different substances, with different physical and chemical properties. The individual materials that form the composite constituents are called: eg matrix and reinforcement. glass fibers, carbon fibers, ceramic fibers, threads of steel and rubber.
Raw materials are the components that are used in the production of alloys and consist of: iron ore, steel scrap, metallurgical coke, fluxes (eg limestone) and oxygen.
Special SPRUE appendix is arranged at the top of the ingots, whose function is to compensate the solidification shrinkage, to limit the eddies, to collect any impurities floating on the molten metal.
Matrices used as a term for the base that contains a certain structure.
Mesophase Standard state intermediate between the crystalline solid and the liquid, characterized by a degree of order less than the first but higher than the latter.
STARTING SOLUTION heat treatment for the development and maintenance purpose in solving the previously precipitated components.
Time needed to reach desired temperature because the temperature of the product reaches, starting from a given temperature, the desired value at the point required.
METAL In metallurgy indicates the aggregation of atoms within molecules tightly together forming a structure.
METALLIZATION Production of a metal layer on a surface by applying a metal. It can be gas or electric arc.
Solid metal (not mercury that is liquid at room temperature), shiny and of high electrical and thermal conductivity. The extraction and processing of metals are called "Metallurgy".
METAL Babbitt bearing metals, soft white tin, lead, copper and antimony in various proportions, used to reduce friction in the bearings as
Metalloids wrongly called "non-metal." Term no longer used.
METALLURGY science that affects the extraction of metals from ores. Technique on the refining, processing and processing of metals in industrial products.
Meta-1) that has a apparent stability outside the conditions defined by the equilibrium diagram. (Eg martensitic transformation).
2) What has a structure different from that corresponding to the stable state.
BY-ENVIRONMENT Environment in which the product is placed during a heat treatment operation. It can be solid, liquid or gas.
Microhardness hardness of a metal determined by using a Vickers or Knoop indenter which is applied a load very low. Fingerprints are usually so small that it must be measured under a microscope.
MICROMETER linear meter, fitted with a micrometric device, used for high precision measurements (micron m).
Microsegregation segregation that takes place in a grain in a crystal or a small particle size.
MICROSTRUCTURE a metal structure, visible under a microscope for high magnification, usually greater than 50x, 100x and 500x 1000x more.
MIREX
dall'altoforno otherwise, the metallic iron is obtained by chemical reaction and not by fusion of the mineral production process of reduction of iron oxide by the chemical reaction of hydrogen and carbon monoxide with the iron oxide in order to obtain metallic iron. This system is used by those nations where natural gas has lower costs (Argentina, etc...) The reducing gas, rises to the top of the oven at a temperature of 350-450 ° C and causes a portion of carbon monoxide and hydrogen are converted respectively into carbon dioxide and water vapor while the ore feed (pellets or granular material such as for the blast furnace) is reduced to metallic iron. The product obtained is placed in the oven as a percentage of 30% and merged with an average of 70% scrap in order to obtain steel.
Modulus of elasticity E 'a measure of the stiffness, defined as the ratio of the stress unit, below the limit of proportionality, and the corresponding value of the compress. In case tensile stress is called the Young's modulus. It can be longitudinal or tangential. The higher the resulting value is high, it will be more rigid structure.
GRINDING complete elimination of surface irregularities by grinding wheels.
WHEELS Units of amount of matter in the International System.
MOLECULE When atoms bond together form the molecule.
This monoclinic crystals of mineral.
Symmetry manifold system in which the three crystallographic axes are perpendicular to each other and in which the parameters are the same cut on the three-faced fundamental (cubic).
NAMOMETRO A nanometer (nm symbol) is a unit of length, corresponding to 10 - 9 meters (ie a millionth of a millimeter).
Nanotechnology research and development of new materials industrializable exploiting the properties of matter at the atomic level (not necessarily talking about a single atom, but of groups of atoms that constitute the basic building blocks of new material), they speak of "nano" technology, because the physico-chemical properties of matter are studied and applied to a size of the order of nanometer = 1 billionth of a meter.
TAPE (ROLL) hot-rolled flat products that immediately after the final step of rolling or after continuous annealing and pickling, is wrapped in coils. The cold rolling is also made.
NEUTRINOS subatomic particles (with no meaning as isolated entities) neutral mass (nothing or almost nothing), free of charge. They can pass through space and matter without a trace.
NEUTRON electrically neutral particles that, together with protons is a constituent of the nucleus of each chemical element.
NICKEL surface coating of a metal part with a nickel layer, a protective and decorative carried out using an electrolytic or reduction (see reducing) chemical. It can be matt or shiny.
Nitrocarburizing thermochemical diffusion treatment in which nitrogen and carbon absorption in the surface layers are made of steel, in conditions close to those of nitriding. Significantly increases the fatigue strength.
NITRIDING thermochemical diffusion treatment which is enhanced by a surface layer of steel components, one of which is ammonia gas. This layer becomes extremely hard and can reach a hardness of 1000 HV.
WHITE nitriding treatment simulation is to reproduce the thermal cycle of nitriding in the absence of half-nitriding atmosphere.
Ion nitriding ion bombardment. The glow discharge takes place in a gaseous mixture, under a pressure lower than atmospheric, in which the product is the iron cathode.
NODE intersection of the lines representing the crystal lattice.
NOMINAL not effective, non-real-es. Nominal thickness.
Standardization will be conducted at a temperature of just over Ac3 (Ac1 for steels hypereutectoid C%> 0.83) followed by cooling in still air. The main task is to homogenize the structure and to refine the grain swollen from previous processing operations on hot. This treatment is not recommended for tool steels and for those self-hardening.
Specific rules (rules) issued voluntary technical by official bodies to harmonize the definition and characterization of products, services, etc.. may be national, European and International.
Nucleation ENDOGENOUS said the right arrangement of atoms within the structure.
HOMOGENEOUS Transformation nucleation of a metal from the liquid to the solid phase with decrease of free energy. Just below the equilibrium temperature (solidification), the solid metal is stable, having lower free energy.
CORE compact central part of the atom that has focused most of its mass.
Homogenizer Heat treatment at relatively high temperature (over 1000 to 1200 ° C), the objective is to eliminate or at least reduce the chemical segregation and improve the workability.
Orbital part of space (volume) of the wave function describing the motion of an electron in an atom or a molecule.
Osmond obsolete term once used to describe a microstructure of iron is not as well defined as Troosite.
OXIDATION 1) chemical reaction in which the atoms involved increases the valence, with a consequent loss of electrons.
2) passivation reaction in which the metal oxide form.
3) chemical reaction in which an element or chemical compound is combined with oxygen.
INTERNAL OXIDATION rainfall to a greater or lesser depth, within a product ferrous oxide formed from oxygen dispersed spread from the surface.
Oxide compound that is derived from the union of oxygen with an example. aluminum oxides, nitrogen oxides, etc..
OXY System for forming and cutting hot slabs of sheet metal and using torches. Preheating temperatures as a function of carbon equivalent Ceq = C + Mn / 6 + (Cr + Mo + V) / 5 + (Ni + Cu) / 15
OVALIZATION error of the cross section to form round pieces. The circularity tolerance allowed is the difference between the maximum diameter and minimum diameter, divided by 2. This value must be less than or equal to the value of IT to the corresponding nominal size divided by 4.
STRAW discontinuity surface type similar to irregular flakes. Stretch in the direction of rolling, the extension depends on the degree of reduction and remain stuck in some places the base metal.
TRENCH SHEETS Parancola or building components in hot-rolled steel or cold-tongued (gargami) male-female connected to each other during the insertion into the ground, forming a continuous wall. Its function is to resist the pressures of the soil, water and overloads.
BASKETS vessel, at the head of the continuous casting line, which receives and holds the liquid steel to be cast, with the task of regulating the flow in continuous casting mold below.
Parameters each of the lengths of the segments that the face of a crystal size on a set of crystallographic axes x, y, z.
Elementary particle constituent of matter smaller than those of atoms, characterized by a particular value of mass that can be anything, as in the photon and neutrino.
PASSIVATION Properties of some metallic elements and alloys (stainless steel) to oxidize the surface, the thin film protects the base metal from corrosion.
LICENSED heat treatment of austenitizing followed by cooling to obtaining suitable facilities in favor of a subsequent drawing or rolling. Harmonics in the wires for cables, cooling occurs in a lead bath at about 425 to 565 ° C.
PEELED ROLLED Manufactured in bars of circular cross section obtained by peeling machine, straightened and polished.
Development hardening hardening penetration by hardening a ferrous product, from its outer surface - to heart.
PERIOD constant time interval after which the evolution of a physical phenomenon that is repeated every time a magnitude assumes the same value. The period is the inverse of the frequency.
PERLITE aggregate of ferrite and cementite resulting from the processing interval bainitic dell'austenite above. It may be in the form of lamellar pearlite (lamellar) and, if distributed uniformly in ferrite matrix, allows good workability especially for carbon steel hardened and quenched and tempered. The structure that enables a longer tool life is usually formed by ~ 10% perlite and 90% ferrite. The globular pearlite (iron) allows good workability for steels with high carbon content. Chromium steels for bearings are annealed ferrite-cementite structure in iron (globular) to have a good machinability.
PERLITIZZAZIONE Heat Treatment Act to obtain a fine microstructure. You run on the tool steel for hot working. After hot deformation, the material is cooled to 500 ° C in still air, then hospitalized in prepared oven to 730 degrees and you run a stop equivalent to 1 hour per inch of thickness.
STAY portion of the thermal cycle during which the temperature is kept constant.
PERMEARE Passing, diffondendovisi penetrate into a body of liquid or gaseous substances eg. the permeability of hydrogen in steel as a function of temperature.
Molecular weight and 'the sum of the atomic weights of all atoms making up the molecule.
Arrangement of atomic planes parallel crystal planes.
FOLD sets the goodness or otherwise of the material to withstand this cold plastic deformation. After folding, you should examine the edges and the outer face of the folded shape. The material will comply if you do not notice cracks, defects or microstrappi details agreed at time of order. The effort of bending must be applied slowly so as not to hinder the plastic flow of the material. The UNI 564 and ASTM A 370 set to the test.
PYROLYSIS chemical reaction consists in submitting to a strong heating a substance or mixture of substances to be able to decompose into smaller molecules (the term most used is cracking).
PYROMETER device used to measure high and low temperatures. It may be in contact, where a sensor detects the temperature or infrared when it is hard to get close to the heat source.
PITTING pitting corrosion, pitting
PLATING operation carried out for aesthetic and security in general is to cover the surface of a material with a layer of another material which can be metallic or nonmetallic.
PLASMA Gas in which all atoms are ionized.
PLASMA NITRIDING The process of plasma nitriding / nitro-carburizing is based on the loss of nitrogen and / or carbon in ferrous metals. This is done in a vacuum of a room where a plasma is triggered at low energy. Following the inclusion of nitrogen which ionizes and accelerates through the substrate to be treated. The treatment is spread into the material to a depth of about 0.8 mm. This technique, combined with a controlled oxidation is the alternative to chrome plating.
PNTA PLASMA Plasma is a layer of matter in which atoms are usually stable, they are excited to form positive ions and free electrons. The deposition of the plasma is produced by an electric arc confined by a flow of gas, achieving very high speeds and temperatures. In this way the powder is melted and impacted on the surface to be coated. The more powder used consists of chromium oxide, aluminum, titanium and carbides.
PLASMA PSTA technology used in the field of overs in hot metal anchor. You can deposit Stellite alloys, carbides, etc..
PLASMA SPRAY This technique allows to deposit particles fuse of a powder material that you wish to deposit. The hot plasma that has an energy to melt the powder of any material injected into it. The microscopic droplets of molten powder are projected at speeds comparable to that of sound, against the surface to be covered, giving rise to the deposition.
PLASTICITY 'Properties of some solids undergo, due to a sufficiently intense mechanical stress, deformation of a permanent nature.
POLYCRYSTALLINE solid containing many crystals also called grains.
POLIEDRA solid limited by a system of polygons faces such plans.
POLYMER Synthetic fluid composed of water and organic high molecular weight (polymers). The drastic quenching, with 35% solution, is just above the oil and can handle a greater range of steels, without risk of breakage. These baths are replacing the oil quenching, more polluting and expensive.
POLYMORPHISM property that has a crystalline substance in different forms without changing its chemical composition.
POTENTIAL
THERMODYNAMIC When two bodies are in contact have different temperatures and heat exchange. The hot cools and heats the cold to the point of equal temperature. In this process the entropy increases and is maximum when the final equilibrium temperatures are equal.
POTENTIAL OF CARBON AND 'a measure of the ability of an environment containing active carbon to alter or maintain, under certain conditions, the carbon content in steel.
ppm (parts per million) with a very small percentage which, commonly, the content is expressed in parts per million of the content of hydrogen, oxygen and nitrogen present in steel (eg 2 ppm = 0.0002%)
PRECIPITATION class of chemical reaction in solution where it forms a slightly soluble product that "falls" from the solution. If the steel contains elements which have high affinity for nitrogen, such as Mn, Mo, Cr, Al, V, Ti, and they contribute to the formation of fine precipitates of nitrides and thus cause an increase in hardness of the nitrided layer, accompanied by a state of compression surface due to increased volume of the compound precipitates.
PREHEAT
O HEATING Heating is carried out before reaching the set temperature. When welding is that the heating is carried out immediately before starting to weld.
First furnace in 4000 BC iron was made from some meteorites. In 1500 BC the Hittites (the mountainous areas of Turkey) began to derive some very abundant mineral in nature, using the first such low-fire kilns. Homes were made in the ground where they were introduced by the iron ore alternating layers of wood or charcoal. The iron was produced in these blocks and spongy material, absorbing small amounts of carbon from the fuel, formed steel.
PRODUCTS powder metallurgy steel powder: a set of steel particles of size even less than 1 micron. Sintered parts: products formed from sintered agglomerated powders and sometimes again subjected to the action of the press. Full-density parts: products made from dust by the joint action of temperature and pressure (hot isostatic compression, extrusion etc..)
LONG PRODUCTS Products section constant defined by a rule which shall determine the current ranges of sizes as well as the shape and dimensional tolerances. This category includes: rods, wire, bar products obtained in hot-rolled bars, forged bars, hollow bars, blasting, white goods, wire products, rolled peeled, ground products, products for fluted or ribbed reinforced concrete products bars, hot rolled steel, railway equipment and material of similar material, piles and piles, reinforcing rods for support of mining, these beams and angular profiles, other profiles, welded, cold formed sections long, tubular products, pipes , seamless tubes, welded tubes, hollow, hollow bars. Standard EN 10079/94
FRP products with cross section whose width is greater than the thickness. Fall into this category products: plain, uncoated, flat hot-rolled non-coated, uncoated cold rolled flat steel, magnetic, grain-oriented electrical steels, plans for wrapping, black stripe, tin plate, sheet and strip tin, chrome plate, hot or cold-rolled flat-coated, flat metal coated, organic coated floors, floors with different coatings, profiled sheets, composite products. Standard EN 10079/94
RECTIFIED PRODUCTS Round bars drawn or peeled which is given a surface quality and dimensional accuracy improved by grinding or grinding and polishing.
Product Back The rods are made by turning and can then be straightened and polishing (rolling). This gives the bar special
characteristics of shape, size and surface finish accuracy. The removal of material is made so that the processed product is generally polished free from defects in lamination and surface decarburization. For technical reasons, ordered some bars as hot rolled products can be considered approximately as turned (peeled), but those products are considered as hot-rolled products, not as cold worked.
DRAWN PRODUCTS steel products having different forms of cross section, obtained after descaling of hot-rolled bars. The bars or coils are cold formed, without
removal of material, on a counter-die. This gives the product special characteristics of shape, dimensional accuracy and surface condition. Furthermore, this leads to an increase in resistance that can be overridden by a heat treatment. The products are supplied in straight bars regardless of their size.
Constituent PROEUTETTOIDE formed during the decomposition dell'austenite eutectoidic before processing (see eutectic).
PROFILE metal rod (or plastic) of constant cross section characterized by a particular profile obtained by rolling, extrusion or drawing. The profiles have standardized dimensions according to specific schedules (profiles L, U, T ..) or are produced to order a case by case basis.
DEPTH OF
HARDENING distance between the surface and the layer where the Vickers hardness, measured with a load of 9.81 N, is equal to 80% of peak demand in surface hardness.
DEPTH OF
NITRIDING distance between the surface of the product and a limit that characterizes the thickness of the layer enriched in nitrogen. This limit must be specified in order (as deep or as hard in μ).
Case depth and distance between the surface layer whose Vickers hardness, measured with a load of 9.81 N, is HV1 = 550
DEPTH OF decarburization distance between the surface of ferrous products and features that limit the thickness of the layer depleted of carbon. This limit can be defined by reference to a structural state, to a level of hardness or the carbon content of the base metal is not altered.
PROPAGATION
Heat by conduction occurs through contact between solid bodies, by convention regards the diffusion of heat in fluids and occurs with transport of matter, radiation is the propagation of non-contact thermal energy in the form of electromagnetic waves.
PHYSICAL properties of the metal or alloy relatively independent of the microstructure and can be measured without the application of a force (eg, density, electrical conductivity, thermal expansion coefficient, lattice parameters and magnetic permeability).
Intrinsic Properties that just depends on the presence of lattice imperfections or impurities in the material. Example of intrinsic properties are the specific heat, latent heat of sublimation, the modulus of elasticity, the energy of cohesion.
MECHANICAL PROPERTIES properties of a material related to its elastic and plastic behavior when stress is applied. Applications where this material can then be dedicated to depend, for example, the elastic modulus, the tensile strength, yield strength from, by lengthening, contraction, hardness, the toughness and the fatigue limit.
PROTON stable elementary particle with positive electric charge that is part of all atomic nuclei.
Hardness
BRINELL Test to determine the hardness of a material by using a ball made of hardened steel or carbide which it is applied to a given load. The result is expressed as a number of Brinell hardness, converted according to official tables (constructed on the basis of experience) in breaking value, Rockwell hardness, Vickers, etc..
FATIGUE TESTING OF Mechanical test where the specimen is stressed repeatedly with a load below the elastic limit.
IMPACT TEST
CHARPY impact tests carried out by means of a pendulum, in which a specimen, usually carved and supported at both ends, is broken dynamically. The energy absorbed is a measure of impact resistance, generally expressed in J.
TEST hardenability (Jominy test) procedure lab to determine the hardenability of a steel or cast iron. The hardenability was determined by heating a standard specimen to above its critical temperature. He then placed the specimen in order to proceed to a rapid cooling by water spray from from quenched. Reached room temperature, run a series of hardness measured from the cold. The results are then reported in a Chart-hardness distances.
A show tenacity
FRACTURE (KIC) procedure which is determined by the strength of the metal to the unstable crack propagation.
TEST DRIVE procedure by which you determine the behavior of a metal subjected to a process of unidirectional deformation.
CRITICAL temperature at which to begin or end a change of structure.
DEW POINT temperature at which the water contained in the controlled atmosphere furnace (endogas) in the form of steam, is partly transformed into liquid.
TRANSITION POINT temperature range at which the resilience fell sharply. For most steels, this interval is located below 0 ° C, the value in ° C is important for those materials that have to work at low temperatures.
PWHT post weld heat treatment
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Aldebaran
 
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Re: Glossary Q-Z

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FRAMEWORK hot-rolled, forged or extruded, generally square cross section bars.
Quaternary four elements.
STRAIGHTENING operation performed to correct curvature or sinuosity of the rolled bars, drawn, forged and so on. The correction is accomplished using cold presses usually horizontal, vertical, rolling or other in order to establish a desired straightness expressed in ‰ es. 1 mm / m. To alloy or very elastic, straightening runs hot (~ 300 ° C °) using, whenever possible, the tempering temperature at end. In addition to facilitating the mechanical action, the material will be free of tension (as opposed to what happens with that cold where the pieces are still partially powered). straightening after annealing, carried out by rolling, raises the hardness of HB 10 (average carbon and alloy steel)
COOLING Conditions under which you make the cooling of a product by subtracting heat: the nature and temperature of the medium-environment, etc. relative movements.
COOLING
Critical conditions that limit the cooling, however, allow the full performance of a specific processing, while avoiding the emergence of a preliminary structure junk. The term must be completed with an indication of the transformation in question (martensite, bainite, etc...)
Cooling controlled cooling from a high temperature in a predetermined, so as to avoid cracking, internal damage, and to obtain the desired microstructure.
COPPER PLATING Operation electrolyte consisting of a metal surface coated with a layer of copper. Is done mainly to give the product a good resistance against atmospheric corrosion.
POISSON RATIO
(0.25 to 0.30 for steel) Absolute value of the relationship between cross-compress and compress longitudinally in a body which is applied to a longitudinal stress, usually in the elastic range. It is used in the formula for calculating the shear modulus.
RATIO raw state solidification, the mechanical properties of steel are not suitable for combat stress in exercise. Therefore, ingots, billets, etc.. shall be subjected to a reduction in fair which gives a fine texture and compact. Forgings is recommended for a reduction of 3.5:1 and 6:1 for the laminates. The r.r. is obtained by dividing the initial section starting with the final section of the product obtained.
SHAVING In the field of mechanics of a product is said to shave by shaving unit linear. The tools are referred to as shaving and control of the measurement is done by measuring laser.
RECALESCENZA temperature rise due to the emission of heat that accompanies the transformation dell'austenite during cooling.
Refractory materials with very high melting point (~ 1580 ° C) used for the internal walls of furnaces and ladles.
YIELD The term is used to describe the effectiveness of a transformation or a steel processing
COMPRESSIVE STRENGTH The maximum compressive strength of a metal that is capable of developing, referring to the beginning.
Break-resistant and 'the maximum effort that the material can withstand.
Flow resistance at nominal constant effort that involves a specific creep in a given time, to a certain constant temperature.
RESISTIVITY resistance of a section of wire of unit length and cross section of unit area. The resistivity of a conductor depends on its nature, the temperature or the intensity of the magnetic field within which it is located.
RESTORATION Heat treatment with the purpose of causing the restore at least part of the physical or mechanical properties of a hardened ferrous products, without apparent modification of the structure.
CRYSTAL LATTICES set of points representing the centers of balance of ions of atoms or molecules, arranged at regular intervals in three directions of space, in strict order for each substance crystallized.
A cubic lattice
The face-centered face-centered cubic structure is stable from 911 ° C to 1392 ° C and is called austenite or γ iron. Austenite is the term used to define the γ solid solution of iron with carbon and other elements. Interatomic distance to 916 ° C = 2.573 A; Distance reticular side of the cube to 916 ° C = 3.639 A
Body-centered cubic lattice Above 1392 ° C the stable structure is body-centered cubic iron or δ that persists up to 1563 ° C, melting temperature. The same structure is stable below 911 ° C (β iron between 768 ° C and 911 ° C in α iron below 768 ° C). Interatomic distance at 20 ° C = 2.48 A (angstron) = 0.000248 μm
Distance reticular side of the cube at 20 ° C = 2.80 A
Adjustments made to the finishing machining in which, with the use of abrasive, minimal amounts of metal are removed in order to obtain products with dimensional tolerances (h 6) and excellent surface roughness Ra 0.4 μm
STRAIGHTNESS For all the bars (rounds, squares, hexagons, dishes, plates and special profiles), a tolerance of straightness that varies depending on the processing undergone by the product. This is measured on sections of one meter and is expressed in ‰ es. Max 1.5 ‰ (1.5 mm to 1000 mm).
Recarburising thermochemical treatment with the aim of restoring the carbon content of the surface layer decarbonized during a previous treatment.
ANNEALING The main task of this heat treatment is to achieve a lowering of hardness of materials deformed hot rolled and cold drawn. In some cases annealing is introduced to eliminate tensions or inhomogeneous structures.
VACUUM ANNEALING Annealing performed at less than atmospheric pressure.
ANNEALING ANTIFIOCCO When the hydrogen content is greater than 2 ppm of heat treatments are performed with stops at temperatures (600-680 ° C) pre-established, very long. In this way, the hydrogen may migrate to the outside without creating rifts within the pieces.
ANNEALING BETA This treatment produces some titanium alloys in the beta phase by heating at a suitable temperature, followed by controlled cooling to prevent its decomposition.
CYCLIC ANNEALING Annealing Process using a predetermined time-temperature cycle and closely monitored to produce specific properties or a certain microstructure.
FULL ANNEALING You run at 20-50 ° C above Ac3 ipoeutettoide steel) or Ac1 (steel hypereutectoid). Stop at this temperature for 2 to 3 minutes per mm thickness of the workpiece. Very slow cooling in the temperature within the range of critical Ac3-Ac1
Final cooling to room temperature with a speed more or less rapid (5 - 30 ° C / h) according to the CCT curve.
Soft annealing heat treatment designed to decrease the hardness of ferrous products, up to a specified level.
STRESS RELIEVING It 's done at temperatures between 600 and 650 ° C (preferably 650) cooled in furnace to 250-300 ° C and subsequent discharge into the air.
STRESS FERRITIZZAZIONE treatment performed after casting gray cast iron or ductile cast iron in order to obtain a predominantly ferritic matrix.
STRESS grain growth annealing at a temperature above Ac3 and hold long enough to get a large bead. Technique to improve the workability of chip removal, but harmful to the toughness. Temperatures between 950 and 1200 ° C with a stay long enough, ll'ingrossamento determine the grain
Soft annealing is performed at 30-50 ° C below the Ac1 point. This treatment does not change the structure but it does give an adequate softening (see softened) and eliminates tension due to earlier works. Cooling can take place in the oven or in the air.
ANNEALING OF BLENDING is performed at high temperatures (1100-1200 ° C) and is intended to reduce, by diffusion, the heterogeneity of chemical composition due to segregation.
STRESS recrystallization 'recommended for cold rolled material and must be performed at a temperature Ac1. During lamination, the structure tends to be the main direction of deformation, the hardness and increases the ability of steel to be subjected to further processing (such as drawing) decreases.
Annealing annealing carried out in half-environment that preserves the original metallic finish, avoiding the oxidation of the metal.
ANNEALING intercritical annealing at a temperature between Ac1 and Ac3
INTERMEDIATE ANNEALING Annealing carried out in one or more stages during production.
Isothermal annealing is performed at 20-30 ° C above Ac3 (ipoeutettoide steel) or Ac1 (steel hypereutectoid).
This heat treatment makes it possible to rebuild the structure and to completely eliminate any strain hardening.
PDG 50 ° C / h, holding at one hour per inch of thickness regime, the ovens must be equipped with forced air circulation and cooling to below Ac1 must be fast to the temperature indicated by the technical specifications. Maintenance until the complete transformation dell'austenite (see TTT curves) for at least 2 hours and then discharge into the air.
SUB-CRITICAL ANNEALING For steels ipoeutettoidi C <0.83% for chip removal process in this heat treatment is not recommended as it is the only one who can make it workable hypereutectoid steels (% C 0.83 to 2.06). You run to a temperature close to Ac1 (-10 ° C) but are very long residence times, 1 h per 10 mm thick beam rods and forged or rolled the whole office. Excellent heat treatment equipment for the cold forging and extrusion. The globulization of cementite can be obtained by subcritical heating.
REDUCING substance or combination of substances which can react with other substances to reduce the number of oxidation (carbon monoxide C. - aluminum - ferro-silicon, etc..)
NEEDLE LINES Mechanical damage on the surface of the artefacts. The defect is caused by friction between the workpiece and parts of machinery used to manufacture.
DISCOVERY heat treatment to which a product undergoes iron after hardening by quenching, in order to bring the mechanical properties at the desired level. After hardening, the material is in a state of severe tension that must be eliminated because their strength, surpassing the tensile strength, could break the material. This is one of the tasks of discovery. The second is to reduce the resistance to the point of compromise between good tensile strength and good toughness.
INDUCTION TEMPERING Tempering of steel obtained by low-frequency induction heating.
DISCOVERY SPONTANEOUS (AUTORINVENIMENTO) suffered by Tempering martensite during quenching. After turning off the water, oil etc.. the heart of the material is still warm, in part autorinviene the external mass.
FOLDING Areas deformation in hot or cold they are superimposed, without the surfaces are completely sealed. The folding occurs as the language and partly welded flat metal surface. Indistinguishable from the longitudinal cracks, presenting an acute angle to the fold surface.
SELECTIVE HEATING Heating intentionally made only on some parts of it (such as surface hardening or curing of a particular region on an artifact).
HEATING Raising the temperature of a product with a predetermined thermal gradient.
Core heating the second stage of reheating, where the temperature is raised to the level required in the entire section of an iron product.
WARM UP: The first stage of reheating, where the temperature is raised.
Wear-resistant coating deposit thin layers of compounds very hard and resistant to wear and corrosion. Some of these are:
Chemical vapor deposition CVD - chemical vapor deposition.
DLC Diamond Like Carbon - deposit of crystalline diamond.
HIP Hot Isostatic Pressing - isostatic pressing (applying heat and pressure to a metal)
Poly Crystalline Diamond PCD - synthetic diamond powder (graphite, in high pressure and temperature, mixed with Ni or Co).
HVOF High Velocity Oxygen Fuel - inflammation process that uses high kinetic energy of compressed gas and heat of combustion to produce carry-low porosity, high load anchorage, and low surface roughness.
Der Rhomboid lattice primitive cell of the face-centered cubic crystal.
SCRAP Scrap processing industries, steel industry, consumer goods and equipment out of use. Contrary to the mineral, their availability is linked to industrial activity.
BROKEN FOR HARDENING Fracture of a metal at a high temperature tempering. May occur more frequently in the case of carbon steel, alloy steel or tool steel with high hardness and low toughness. The cracks usually start from threads, holes, sharp edges and any point can raise the local stress. It 'a result of stress due to the increase in specific volume related to the formation of martensite.
ROUGHNESS Complex microgeometry errors present on a surface with any work. Is detected across the orientation of the grooves prevalent and usually expressed in microns (m).
SANDBLASTING Mechanical pickling by grit thrown very hard on the pieces at high speed.
TEST portion of material from a manufactured and intended for the determination of physical evidence of the steels.
Welding Technique permanent union with the formation of a welded joint of two pieces, usually metal, which is based either on the supply of heat produced in various ways or application of high pressures.
Mechanical deburring operation is run to the end of the artifacts to remove the fringes formed during metal cutting saw.
SCAGLIA
(Calamine) A mixture of iron oxide formed during hot deformation or heat treatment at high temperatures and can be removed with etching or machining.
SCAGLIA IMPRESSA Signs on the laminate surface that vary in shape, thickness and frequency. The scale depends on the intrinsic scaling imprinted on the workpiece surface before or during hot rolling.
Scarfing mechanical removal of the weld bead.
SLAG mixture that is produced during the refining in the converter and which floats on steel liquid. By exchange reactions with the slag in the steel you can control the percentage of elements such as phosphorus, sulfur and silicon and, in part, the content of inclusions.
Creep (CREEP) The process of deformation at constant load, high temperature. The specimen is subjected to a number of hours to a certain load-constant temperature in a heating furnace.
SEGREGATION term often used to liquazione. Uneven distribution, the mass of metal solidified, the alloy elements and impurities in the steel itself and instead were distributed evenly in the liquid mass to start.
SEM Chemical analysis (microanalysis) in the Scanning Electron Microscope is achieved by measuring the energy and intensity distribution of X-rays generated by electron beam on the sample using a detector energy dispersive EDS (energy dispersive spectrometry). The analysis that is produced can be either the area at that time is maximized, or, by stopping the scanning electron beam, a point of interest on the sample surface (microanalysis). Since the portion of space excited by electron beam, which produces the spectrum X, is a few microns, the SEM + EDS is a powerful tool to investigate solid chemically heterogeneous at the microscopic scale.
SEMI / Semi-finished steel products, hot-worked, that underwent a partial transformation process, which requires another stage of processing to become a finished piece. It can be square, rectangular and round (billets, blooms, etc...)
AWARENESS process of considerable importance in the austenitic stainless steels in which to stay around 600 ° C, follows the precipitation of Cr carbides at the grain boundary (see coupling). If the Cr content locally free falls below 12%, the grain boundary becomes susceptible to attack local corrosion (intergranular corrosion). Also called the 'the phenomenon that makes some stainless steels susceptible to intergranular corrosion. Other times it is used to define a specific heat treatment performed to test the susceptibility of a material to reach the predetermined values.
Serendip 'discover something unexpected looking for another.
SEVERITY 'hardening and' characterized by a value of H on the capacity of the means of removing heat annealing
Cleavage Properties of some minerals crystallized, consisting of easy divisibility along flat surfaces, called cleavage planes.
EFFORTS TO
COOLING residual stresses resulting from a non-uniform temperature distribution during cooling.
Residual stresses that internal stress is not dependent on external stress due to work hardening, phase changes, or temperature gradients are too high, but may arise eg. by thermal expansion or deformation prevented.
Efforts thermal stress in a metal caused by a non-uniform temperature distribution.
ROUGHING outline a block of metal, synonymous with turning and milling.
SHERARDIZZAZIONE thermochemical surface protection treatment with zinc dust.
THERMAL SHOCK Development of a rapid temperature gradient (heating) resulting in higher efforts in the structure.
STEEL field of metallurgy which deals with techniques useful for the production and initial processing of cast iron, steel and ferro-alloy from the iron ore.
Siliconized thermochemical treatment in order to obtain a surface enrichment of silicon.
SYMMETRY It is said that a physical system is symmetric if it looks the same before and after turning around a hypothetical segment (the crystal with the same faces again).
SINTERING operation fusion welding of metallic material in powder form and made by pressing and heating (up to 1500 ° C), part of the powder metallurgy. This technique is also called HIP (Hot-Isostatic Pressing) hot isostatic pressing.
Sinter operation combined in a single step in a furnace, sintering and heat treatment. The dust content in the alloy rather high, after hot-pressing, are subjected to rapid cooling (using the same atmosphere that circulates in the oven) within an appropriate range of quenching. This method provides, at competitive costs, advantages in terms of mechanical strength, static and fatigue.
Combined system of interdependent parts that contribute to a certain result or assembled so as to form a coherent whole.
LADLE container lined with refractory material which is collected in the liquid steel from the furnace od'affinazione.
SKIN PASS Also called passage of the skin. It consists of a rolling process (hot or cold) that affects only the surface of the product and gives it a shiny and smooth. The structural characteristics and mechanical properties of the mass, in general, are not changed.
BLOWING bubbles under the skin caused by gases during solidification of ingots, billets, etc..
GROOVES anomalies which are formed mainly when some defects in the preform are stretched and extended during the rolling process.
SOLFOCARBONITRURAZIONE thermochemical treatment in order to obtain a surface enrichment of sulfur, carbon and nitrogen.
SOLIDUS solidification end points of all the alloys.
SOLUBILITY maximum amount of solute, in grams, which is dissolved in one hundred grams of solution.
SOLUBILIZATION treatment generally resulted in 1000 - 1100 ° C followed by rapid cooling in water or forced air (hardening of austenitic steels).
Solute in a solution of two components, that is present in smaller quantities.
Solid solution phase crystalline solid, homogeneous, containing two or more chemical species.
Solvent in a solution of two components, that is present in quantity at the highest concentration.
Solvus curves representing the mutual solubility of two solid-state components as a function of temperature.
SORBITOL aggregate of fine globules of cementite or carbide (not resolvable by light microscopy) in the ferrite matrix. The structure is the classic one of the steels, but has no satisfactory workability.
Cooling with cooling below the temperature at which one has the balance of phase transformation, usually below room temperature (-70 ° C -80 ° C).
SOVRACARBURAZIONE excess surface carbon content, compared to the standard required as a result of cementation.
Oversize limited thickness of metal that is left after the first roughing operation in order to be able to eliminate, in the finishing phase, distortion and other surface defects caused by heat treatments or other operations.
Overheating Heating a steel or an alloy to a temperature so high that the combination of its properties is significantly altered. In the event that the original property are not recoverable by a subsequent heat treatment, such heating will be referred to as "burning".
SHOULDER HARNESS AND Utensils drawing particularly suited to drawing plates. They are part of the die piece and are adjustable to allow the sides to get the measures contained intermediate between the minimum and maximum of the die itself. Are adjusted by means of wedges, plates and screws.
OFF Rapid cooling of a piece by a high temperature (austenitizing), by immersion in a useful way: water, oil, polymer etc..
SPRAY FORMING Forming an ingot steel by the spray of atomized in an inert atmosphere. This process is regarded as an intermediate technology between conventional and powder metallurgy.
STABILIZATION heat treatment to avoid subsequent changes in size during machining.
STABILIZATION DELL'AUSTENITE RESIDUAL (TREATMENT UNDER ZERO) phenomenon that reduces or eliminates the possibility of transformation dell'austenite residual martensite during cooling to a temperature lower (subcooling at -70 -80 ° C) ambient temperature.
PRINTED artifact produced by injection molding, hot or cold.
DIE matrix used for molding pieces in series.
STATE SUPPLY A detailed description of the materials, like steel, heat treatment, surface condition etc..
Metastable state is said to have been a non-equilibrium to equilibrium where the changes are subtle and very long (centuries).
Native state is not yet separated from the mineral element that contains eg. sulfur combined with chalk or limestone.
This natural state of material that has not undergone heat treatment after deformation, hot or cold.
STATE SURFACE The surface desired to be designated at the time of quotation request and order to the classes required by the standards of quality of product, eg. laminate raw cl. D, EN 10221.
Stars show hard wear resistant to withstand high temperatures.
Stirring / electromagnetic stirrer Stirrers (EMS Electro Magnetic Stirrer) placed on the basket and / or on the streets of casting in order to stir the liquid to contain the formation of segregation and to facilitate the flotation of inclusions.
Spreading layer surface layer formed during a thermal treatment, which contains the information provided in the course of treatment. The content of these elements decreases continuously from the outside. The precipitates (see precipitation) can be spread in the state of nitrides, carbides etc..
Hardened layer surface layer of a steel whose composition was modified by adding a high temperature of carbon, nitrogen, chromium, or other elements.
STRUCTURE
Metallography and 'morphology in which two or more phases of a metal s'aggregano. The term is also used to define the structures observed and photographed by light microscopy.
Effect of stringers sometimes obtained during a hot deformation of steel This creates difficulties in machining. .
Amorphous structure with three-dimensional organization of atoms or molecules are disordered.
CRYSTALLINE STRUCTURE structure with organization of atoms or molecules are orderly and regular. This is given by the regular repetition in the three spatial directions of a base unit that the unit cell. In metallurgical parlance, the term is also used to define the structure visible on bright samples of resilience after breaking or collapsing objects to fatigue failure.
PRIMARY STRUCTURE initial solidification structure, which is considered abnormal, classical material not sufficiently processed during rolling or forging.
Sublime passage from solid to gaseous state and vice versa.
SURFACE Outside of a body, the boundary that marks the space occupied by a body and separates it from the surrounding space.
Reheating OVERHEAT performed in conditions of temperature and duration as to cause an abnormal enlargement of the grain.
TEMPERATURE austenitizing temperature at which a steel is completely composed of austenite. From this structure there all the transformations that are obtained during cooling.
Transformation temperature Acm. In a hypereutectoid steel, the temperature at which the cementite is completely transformed into austenite during heating.
Ac1. Temperature at which austenite begins to form during heating.
Ac3. Temperature at which transformation of ferrite into austenite is completed during heating.
AC4. Temperature for which the austenite is transformed into delta ferrite during heating.
AECMA, E1, E3, E4. Temperature of phase change at equilibrium.
Arcm. In a hypereutectoid steel, the temperature at which cementite begins to form during cooling.
Ar1. The temperature at which transformation of austenite into ferrite (steel ipoeutettoidici) or more ferrite cementite (steel or eutectoidic hypereutectoid) is completed during cooling.
AR3. Temperature at which austenite begins to transform into ferrite during cooling.
AR4. The temperature at which delta ferrite transforms into austenite during cooling.
A2 critical point of magnetism (~ 769 ° C). Exceeding this temperature, dissolves the residual magnetism.
Ms. temperature at which, during cooling, the transformation dell'austenite in martensite (martensite start).
Mf. Temperature at which the martensite transformation in dell'austenite is virtually complete (martensite finish).
All transformations, with the exception of martensite, occur at lower temperatures during cooling than heating.
The temperature at which it was formed 10%, 50% and 90% of martensite are deductible by the following formula:
M Ms = 10% - 10 ° C ± 3
M Ms = 50% - 47 ° C ± 6
90% M = Ms - 103 ° C ± 12
Ms = M f - 215 ° C ± 15
Temperature at which a phase change occurs. The term is used to indicate the temperature limit of a range of transformation. The following symbols are used for steels and cast irons:
HOLD TIME time during which the piece is maintained in an oven at the preset temperature.
Time spent time that elapses from when the piece has reached the set temperature at heart and the subsequent change in temperature. Normally you use to stay for ½ hour per inch of thickness in the process of quenching and tempering at 1 hr. These parameters are valid for thicknesses over 50 mm.
TEMPERING operation that is to cool a product faster than iron in still air. It 'a good idea not to resort to half tempering more drastic than necessary, because, with increased cooling rate, the greater the tension in the pieces. The baths for hardening must be agitated to prevent, vapor bubbles remain on the material. The bathrooms are commonly used: gas mixtures (subzero treatment), water, bath salts, polymers (water with additives), oil, forced air or calm. The weight of the bathrooms should be at least 10-15 times higher than that of the material to harden. At the end of quenching, the bath temperature should not exceed 49 ° C.
Hardened hardening depth that is at least equal to the distance between surface and core of the piece.
INDUCTION HARDENING Form hardening in which the heating is effected by current induced by coils. The temperature must be higher than Ac3. Usually it is not feasible on thicknesses up to 6 mm and preferably is to be extended in diameter from 14 to 150 mm
Operation of direct hardening hardening artifacts cemented directly from the carburizing temperature.
WATER HARDENING Hardening carried out in water cooling medium.
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Aldebaran
 
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Re: Glossary Q-Z

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FRAMEWORK hot-rolled, forged or extruded, generally square cross section bars.
Quaternary four elements.
STRAIGHTENING operation performed to correct curvature or sinuosity of the rolled bars, drawn, forged and so on. The correction is accomplished using cold presses usually horizontal, vertical, rolling or other in order to establish a desired straightness expressed in ‰ es. 1 mm / m. To alloy or very elastic, straightening runs hot (~ 300 ° C °) using, whenever possible, the tempering temperature at end. In addition to facilitating the mechanical action, the material will be free of tension (as opposed to what happens with that cold where the pieces are still partially powered). straightening after annealing, carried out by rolling, raises the hardness of HB 10 (average carbon and alloy steel)
COOLING Conditions under which you make the cooling of a product by subtracting heat: the nature and temperature of the medium-environment, etc. relative movements.
COOLING
Critical conditions that limit the cooling, however, allow the full performance of a specific processing, while avoiding the emergence of a preliminary structure junk. The term must be completed with an indication of the transformation in question (martensite, bainite, etc...)
Cooling controlled cooling from a high temperature in a predetermined, so as to avoid cracking, internal damage, and to obtain the desired microstructure.
COPPER PLATING Operation electrolyte consisting of a metal surface coated with a layer of copper. Is done mainly to give the product a good resistance against atmospheric corrosion.
POISSON RATIO
(0.25 to 0.30 for steel) Absolute value of the relationship between cross-compress and compress longitudinally in a body which is applied to a longitudinal stress, usually in the elastic range. It is used in the formula for calculating the shear modulus.
RATIO raw state solidification, the mechanical properties of steel are not suitable for combat stress in exercise. Therefore, ingots, billets, etc.. shall be subjected to a reduction in fair which gives a fine texture and compact. Forgings is recommended for a reduction of 3.5:1 and 6:1 for the laminates. The r.r. is obtained by dividing the initial section starting with the final section of the product obtained.
SHAVING In the field of mechanics of a product is said to shave by shaving unit linear. The tools are referred to as shaving and control of the measurement is done by measuring laser.
RECALESCENZA temperature rise due to the emission of heat that accompanies the transformation dell'austenite during cooling.
Refractory materials with very high melting point (~ 1580 ° C) used for the internal walls of furnaces and ladles.
YIELD The term is used to describe the effectiveness of a transformation or a steel processing
COMPRESSIVE STRENGTH The maximum compressive strength of a metal that is capable of developing, referring to the beginning.
Break-resistant and 'the maximum effort that the material can withstand.
Flow resistance at nominal constant effort that involves a specific creep in a given time, to a certain constant temperature.
RESISTIVITY resistance of a section of wire of unit length and cross section of unit area. The resistivity of a conductor depends on its nature, the temperature or the intensity of the magnetic field within which it is located.
RESTORATION Heat treatment with the purpose of causing the restore at least part of the physical or mechanical properties of a hardened ferrous products, without apparent modification of the structure.
CRYSTAL LATTICES set of points representing the centers of balance of ions of atoms or molecules, arranged at regular intervals in three directions of space, in strict order for each substance crystallized.
A cubic lattice
The face-centered face-centered cubic structure is stable from 911 ° C to 1392 ° C and is called austenite or γ iron. Austenite is the term used to define the γ solid solution of iron with carbon and other elements. Interatomic distance to 916 ° C = 2.573 A; Distance reticular side of the cube to 916 ° C = 3.639 A
Body-centered cubic lattice Above 1392 ° C the stable structure is body-centered cubic iron or δ that persists up to 1563 ° C, melting temperature. The same structure is stable below 911 ° C (β iron between 768 ° C and 911 ° C in α iron below 768 ° C). Interatomic distance at 20 ° C = 2.48 A (angstron) = 0.000248 μm
Distance reticular side of the cube at 20 ° C = 2.80 A
Adjustments made to the finishing machining in which, with the use of abrasive, minimal amounts of metal are removed in order to obtain products with dimensional tolerances (h 6) and excellent surface roughness Ra 0.4 μm
STRAIGHTNESS For all the bars (rounds, squares, hexagons, dishes, plates and special profiles), a tolerance of straightness that varies depending on the processing undergone by the product. This is measured on sections of one meter and is expressed in ‰ es. Max 1.5 ‰ (1.5 mm to 1000 mm).
Recarburising thermochemical treatment with the aim of restoring the carbon content of the surface layer decarbonized during a previous treatment.
ANNEALING The main task of this heat treatment is to achieve a lowering of hardness of materials deformed hot rolled and cold drawn. In some cases annealing is introduced to eliminate tensions or inhomogeneous structures.
VACUUM ANNEALING Annealing performed at less than atmospheric pressure.
ANNEALING ANTIFIOCCO When the hydrogen content is greater than 2 ppm of heat treatments are performed with stops at temperatures (600-680 ° C) pre-established, very long. In this way, the hydrogen may migrate to the outside without creating rifts within the pieces.
ANNEALING BETA This treatment produces some titanium alloys in the beta phase by heating at a suitable temperature, followed by controlled cooling to prevent its decomposition.
CYCLIC ANNEALING Annealing Process using a predetermined time-temperature cycle and closely monitored to produce specific properties or a certain microstructure.
FULL ANNEALING You run at 20-50 ° C above Ac3 ipoeutettoide steel) or Ac1 (steel hypereutectoid). Stop at this temperature for 2 to 3 minutes per mm thickness of the workpiece. Very slow cooling in the temperature within the range of critical Ac3-Ac1
Final cooling to room temperature with a speed more or less rapid (5 - 30 ° C / h) according to the CCT curve.
Soft annealing heat treatment designed to decrease the hardness of ferrous products, up to a specified level.
STRESS RELIEVING It 's done at temperatures between 600 and 650 ° C (preferably 650) cooled in furnace to 250-300 ° C and subsequent discharge into the air.
STRESS FERRITIZZAZIONE treatment performed after casting gray cast iron or ductile cast iron in order to obtain a predominantly ferritic matrix.
STRESS grain growth annealing at a temperature above Ac3 and hold long enough to get a large bead. Technique to improve the workability of chip removal, but harmful to the toughness. Temperatures between 950 and 1200 ° C with a stay long enough, ll'ingrossamento determine the grain
Soft annealing is performed at 30-50 ° C below the Ac1 point. This treatment does not change the structure but it does give an adequate softening (see softened) and eliminates tension due to earlier works. Cooling can take place in the oven or in the air.
ANNEALING OF BLENDING is performed at high temperatures (1100-1200 ° C) and is intended to reduce, by diffusion, the heterogeneity of chemical composition due to segregation.
STRESS recrystallization 'recommended for cold rolled material and must be performed at a temperature Ac1. During lamination, the structure tends to be the main direction of deformation, the hardness and increases the ability of steel to be subjected to further processing (such as drawing) decreases.
Annealing annealing carried out in half-environment that preserves the original metallic finish, avoiding the oxidation of the metal.
ANNEALING intercritical annealing at a temperature between Ac1 and Ac3
INTERMEDIATE ANNEALING Annealing carried out in one or more stages during production.
Isothermal annealing is performed at 20-30 ° C above Ac3 (ipoeutettoide steel) or Ac1 (steel hypereutectoid).
This heat treatment makes it possible to rebuild the structure and to completely eliminate any strain hardening.
PDG 50 ° C / h, holding at one hour per inch of thickness regime, the ovens must be equipped with forced air circulation and cooling to below Ac1 must be fast to the temperature indicated by the technical specifications. Maintenance until the complete transformation dell'austenite (see TTT curves) for at least 2 hours and then discharge into the air.
SUB-CRITICAL ANNEALING For steels ipoeutettoidi C <0.83% for chip removal process in this heat treatment is not recommended as it is the only one who can make it workable hypereutectoid steels (% C 0.83 to 2.06). You run to a temperature close to Ac1 (-10 ° C) but are very long residence times, 1 h per 10 mm thick beam rods and forged or rolled the whole office. Excellent heat treatment equipment for the cold forging and extrusion. The globulization of cementite can be obtained by subcritical heating.
REDUCING substance or combination of substances which can react with other substances to reduce the number of oxidation (carbon monoxide C. - aluminum - ferro-silicon, etc..)
NEEDLE LINES Mechanical damage on the surface of the artefacts. The defect is caused by friction between the workpiece and parts of machinery used to manufacture.
DISCOVERY heat treatment to which a product undergoes iron after hardening by quenching, in order to bring the mechanical properties at the desired level. After hardening, the material is in a state of severe tension that must be eliminated because their strength, surpassing the tensile strength, could break the material. This is one of the tasks of discovery. The second is to reduce the resistance to the point of compromise between good tensile strength and good toughness.
INDUCTION TEMPERING Tempering of steel obtained by low-frequency induction heating.
DISCOVERY SPONTANEOUS (AUTORINVENIMENTO) suffered by Tempering martensite during quenching. After turning off the water, oil etc.. the heart of the material is still warm, in part autorinviene the external mass.
FOLDING Areas deformation in hot or cold they are superimposed, without the surfaces are completely sealed. The folding occurs as the language and partly welded flat metal surface. Indistinguishable from the longitudinal cracks, presenting an acute angle to the fold surface.
SELECTIVE HEATING Heating intentionally made only on some parts of it (such as surface hardening or curing of a particular region on an artifact).
HEATING Raising the temperature of a product with a predetermined thermal gradient.
Core heating the second stage of reheating, where the temperature is raised to the level required in the entire section of an iron product.
WARM UP: The first stage of reheating, where the temperature is raised.
Wear-resistant coating deposit thin layers of compounds very hard and resistant to wear and corrosion. Some of these are:
Chemical vapor deposition CVD - chemical vapor deposition.
DLC Diamond Like Carbon - deposit of crystalline diamond.
HIP Hot Isostatic Pressing - isostatic pressing (applying heat and pressure to a metal)
Poly Crystalline Diamond PCD - synthetic diamond powder (graphite, in high pressure and temperature, mixed with Ni or Co).
HVOF High Velocity Oxygen Fuel - inflammation process that uses high kinetic energy of compressed gas and heat of combustion to produce carry-low porosity, high load anchorage, and low surface roughness.
Der Rhomboid lattice primitive cell of the face-centered cubic crystal.
SCRAP Scrap processing industries, steel industry, consumer goods and equipment out of use. Contrary to the mineral, their availability is linked to industrial activity.
BROKEN FOR HARDENING Fracture of a metal at a high temperature tempering. May occur more frequently in the case of carbon steel, alloy steel or tool steel with high hardness and low toughness. The cracks usually start from threads, holes, sharp edges and any point can raise the local stress. It 'a result of stress due to the increase in specific volume related to the formation of martensite.
ROUGHNESS Complex microgeometry errors present on a surface with any work. Is detected across the orientation of the grooves prevalent and usually expressed in microns (m).
SANDBLASTING Mechanical pickling by grit thrown very hard on the pieces at high speed.
TEST portion of material from a manufactured and intended for the determination of physical evidence of the steels.
Welding Technique permanent union with the formation of a welded joint of two pieces, usually metal, which is based either on the supply of heat produced in various ways or application of high pressures.
Mechanical deburring operation is run to the end of the artifacts to remove the fringes formed during metal cutting saw.
SCAGLIA
(Calamine) A mixture of iron oxide formed during hot deformation or heat treatment at high temperatures and can be removed with etching or machining.
SCAGLIA IMPRESSA Signs on the laminate surface that vary in shape, thickness and frequency. The scale depends on the intrinsic scaling imprinted on the workpiece surface before or during hot rolling.
Scarfing mechanical removal of the weld bead.
SLAG mixture that is produced during the refining in the converter and which floats on steel liquid. By exchange reactions with the slag in the steel you can control the percentage of elements such as phosphorus, sulfur and silicon and, in part, the content of inclusions.
Creep (CREEP) The process of deformation at constant load, high temperature. The specimen is subjected to a number of hours to a certain load-constant temperature in a heating furnace.
SEGREGATION term often used to liquazione. Uneven distribution, the mass of metal solidified, the alloy elements and impurities in the steel itself and instead were distributed evenly in the liquid mass to start.
SEM Chemical analysis (microanalysis) in the Scanning Electron Microscope is achieved by measuring the energy and intensity distribution of X-rays generated by electron beam on the sample using a detector energy dispersive EDS (energy dispersive spectrometry). The analysis that is produced can be either the area at that time is maximized, or, by stopping the scanning electron beam, a point of interest on the sample surface (microanalysis). Since the portion of space excited by electron beam, which produces the spectrum X, is a few microns, the SEM + EDS is a powerful tool to investigate solid chemically heterogeneous at the microscopic scale.
SEMI / Semi-finished steel products, hot-worked, that underwent a partial transformation process, which requires another stage of processing to become a finished piece. It can be square, rectangular and round (billets, blooms, etc...)
AWARENESS process of considerable importance in the austenitic stainless steels in which to stay around 600 ° C, follows the precipitation of Cr carbides at the grain boundary (see coupling). If the Cr content locally free falls below 12%, the grain boundary becomes susceptible to attack local corrosion (intergranular corrosion). Also called the 'the phenomenon that makes some stainless steels susceptible to intergranular corrosion. Other times it is used to define a specific heat treatment performed to test the susceptibility of a material to reach the predetermined values.
Serendip 'discover something unexpected looking for another.
SEVERITY 'hardening and' characterized by a value of H on the capacity of the means of removing heat annealing
Cleavage Properties of some minerals crystallized, consisting of easy divisibility along flat surfaces, called cleavage planes.
EFFORTS TO
COOLING residual stresses resulting from a non-uniform temperature distribution during cooling.
Residual stresses that internal stress is not dependent on external stress due to work hardening, phase changes, or temperature gradients are too high, but may arise eg. by thermal expansion or deformation prevented.
Efforts thermal stress in a metal caused by a non-uniform temperature distribution.
ROUGHING outline a block of metal, synonymous with turning and milling.
SHERARDIZZAZIONE thermochemical surface protection treatment with zinc dust.
THERMAL SHOCK Development of a rapid temperature gradient (heating) resulting in higher efforts in the structure.
STEEL field of metallurgy which deals with techniques useful for the production and initial processing of cast iron, steel and ferro-alloy from the iron ore.
Siliconized thermochemical treatment in order to obtain a surface enrichment of silicon.
SYMMETRY It is said that a physical system is symmetric if it looks the same before and after turning around a hypothetical segment (the crystal with the same faces again).
SINTERING operation fusion welding of metallic material in powder form and made by pressing and heating (up to 1500 ° C), part of the powder metallurgy. This technique is also called HIP (Hot-Isostatic Pressing) hot isostatic pressing.
Sinter operation combined in a single step in a furnace, sintering and heat treatment. The dust content in the alloy rather high, after hot-pressing, are subjected to rapid cooling (using the same atmosphere that circulates in the oven) within an appropriate range of quenching. This method provides, at competitive costs, advantages in terms of mechanical strength, static and fatigue.
Combined system of interdependent parts that contribute to a certain result or assembled so as to form a coherent whole.
LADLE container lined with refractory material which is collected in the liquid steel from the furnace od'affinazione.
SKIN PASS Also called passage of the skin. It consists of a rolling process (hot or cold) that affects only the surface of the product and gives it a shiny and smooth. The structural characteristics and mechanical properties of the mass, in general, are not changed.
BLOWING bubbles under the skin caused by gases during solidification of ingots, billets, etc..
GROOVES anomalies which are formed mainly when some defects in the preform are stretched and extended during the rolling process.
SOLFOCARBONITRURAZIONE thermochemical treatment in order to obtain a surface enrichment of sulfur, carbon and nitrogen.
SOLIDUS solidification end points of all the alloys.
SOLUBILITY maximum amount of solute, in grams, which is dissolved in one hundred grams of solution.
SOLUBILIZATION treatment generally resulted in 1000 - 1100 ° C followed by rapid cooling in water or forced air (hardening of austenitic steels).
Solute in a solution of two components, that is present in smaller quantities.
Solid solution phase crystalline solid, homogeneous, containing two or more chemical species.
Solvent in a solution of two components, that is present in quantity at the highest concentration.
Solvus curves representing the mutual solubility of two solid-state components as a function of temperature.
SORBITOL aggregate of fine globules of cementite or carbide (not resolvable by light microscopy) in the ferrite matrix. The structure is the classic one of the steels, but has no satisfactory workability.
Cooling with cooling below the temperature at which one has the balance of phase transformation, usually below room temperature (-70 ° C -80 ° C).
SOVRACARBURAZIONE excess surface carbon content, compared to the standard required as a result of cementation.
Oversize limited thickness of metal that is left after the first roughing operation in order to be able to eliminate, in the finishing phase, distortion and other surface defects caused by heat treatments or other operations.
Overheating Heating a steel or an alloy to a temperature so high that the combination of its properties is significantly altered. In the event that the original property are not recoverable by a subsequent heat treatment, such heating will be referred to as "burning".
SHOULDER HARNESS AND Utensils drawing particularly suited to drawing plates. They are part of the die piece and are adjustable to allow the sides to get the measures contained intermediate between the minimum and maximum of the die itself. Are adjusted by means of wedges, plates and screws.
OFF Rapid cooling of a piece by a high temperature (austenitizing), by immersion in a useful way: water, oil, polymer etc..
SPRAY FORMING Forming an ingot steel by the spray of atomized in an inert atmosphere. This process is regarded as an intermediate technology between conventional and powder metallurgy.
STABILIZATION heat treatment to avoid subsequent changes in size during machining.
STABILIZATION DELL'AUSTENITE RESIDUAL (TREATMENT UNDER ZERO) phenomenon that reduces or eliminates the possibility of transformation dell'austenite residual martensite during cooling to a temperature lower (subcooling at -70 -80 ° C) ambient temperature.
PRINTED artifact produced by injection molding, hot or cold.
DIE matrix used for molding pieces in series.
STATE SUPPLY A detailed description of the materials, like steel, heat treatment, surface condition etc..
Metastable state is said to have been a non-equilibrium to equilibrium where the changes are subtle and very long (centuries).
Native state is not yet separated from the mineral element that contains eg. sulfur combined with chalk or limestone.
This natural state of material that has not undergone heat treatment after deformation, hot or cold.
STATE SURFACE The surface desired to be designated at the time of quotation request and order to the classes required by the standards of quality of product, eg. laminate raw cl. D, EN 10221.
Stars show hard wear resistant to withstand high temperatures.
Stirring / electromagnetic stirrer Stirrers (EMS Electro Magnetic Stirrer) placed on the basket and / or on the streets of casting in order to stir the liquid to contain the formation of segregation and to facilitate the flotation of inclusions.
Spreading layer surface layer formed during a thermal treatment, which contains the information provided in the course of treatment. The content of these elements decreases continuously from the outside. The precipitates (see precipitation) can be spread in the state of nitrides, carbides etc..
Hardened layer surface layer of a steel whose composition was modified by adding a high temperature of carbon, nitrogen, chromium, or other elements.
STRUCTURE
Metallography and 'morphology in which two or more phases of a metal s'aggregano. The term is also used to define the structures observed and photographed by light microscopy.
Effect of stringers sometimes obtained during a hot deformation of steel This creates difficulties in machining. .
Amorphous structure with three-dimensional organization of atoms or molecules are disordered.
CRYSTALLINE STRUCTURE structure with organization of atoms or molecules are orderly and regular. This is given by the regular repetition in the three spatial directions of a base unit that the unit cell. In metallurgical parlance, the term is also used to define the structure visible on bright samples of resilience after breaking or collapsing objects to fatigue failure.
PRIMARY STRUCTURE initial solidification structure, which is considered abnormal, classical material not sufficiently processed during rolling or forging.
Sublime passage from solid to gaseous state and vice versa.
SURFACE Outside of a body, the boundary that marks the space occupied by a body and separates it from the surrounding space.
Reheating OVERHEAT performed in conditions of temperature and duration as to cause an abnormal enlargement of the grain.
TEMPERATURE austenitizing temperature at which a steel is completely composed of austenite. From this structure there all the transformations that are obtained during cooling.
Transformation temperature Acm. In a hypereutectoid steel, the temperature at which the cementite is completely transformed into austenite during heating.
Ac1. Temperature at which austenite begins to form during heating.
Ac3. Temperature at which transformation of ferrite into austenite is completed during heating.
AC4. Temperature for which the austenite is transformed into delta ferrite during heating.
AECMA, E1, E3, E4. Temperature of phase change at equilibrium.
Arcm. In a hypereutectoid steel, the temperature at which cementite begins to form during cooling.
Ar1. The temperature at which transformation of austenite into ferrite (steel ipoeutettoidici) or more ferrite cementite (steel or eutectoidic hypereutectoid) is completed during cooling.
AR3. Temperature at which austenite begins to transform into ferrite during cooling.
AR4. The temperature at which delta ferrite transforms into austenite during cooling.
A2 critical point of magnetism (~ 769 ° C). Exceeding this temperature, dissolves the residual magnetism.
Ms. temperature at which, during cooling, the transformation dell'austenite in martensite (martensite start).
Mf. Temperature at which the martensite transformation in dell'austenite is virtually complete (martensite finish).
All transformations, with the exception of martensite, occur at lower temperatures during cooling than heating.
The temperature at which it was formed 10%, 50% and 90% of martensite are deductible by the following formula:
M Ms = 10% - 10 ° C ± 3
M Ms = 50% - 47 ° C ± 6
90% M = Ms - 103 ° C ± 12
Ms = M f - 215 ° C ± 15
Temperature at which a phase change occurs. The term is used to indicate the temperature limit of a range of transformation. The following symbols are used for steels and cast irons:
HOLD TIME time during which the piece is maintained in an oven at the preset temperature.
Time spent time that elapses from when the piece has reached the set temperature at heart and the subsequent change in temperature. Normally you use to stay for ½ hour per inch of thickness in the process of quenching and tempering at 1 hr. These parameters are valid for thicknesses over 50 mm.
TEMPERING operation that is to cool a product faster than iron in still air. It 'a good idea not to resort to half tempering more drastic than necessary, because, with increased cooling rate, the greater the tension in the pieces. The baths for hardening must be agitated to prevent, vapor bubbles remain on the material. The bathrooms are commonly used: gas mixtures (subzero treatment), water, bath salts, polymers (water with additives), oil, forced air or calm. The weight of the bathrooms should be at least 10-15 times higher than that of the material to harden. At the end of quenching, the bath temperature should not exceed 49 ° C.
Hardened hardening depth that is at least equal to the distance between surface and core of the piece.
INDUCTION HARDENING Form hardening in which the heating is effected by current induced by coils. The temperature must be higher than Ac3. Usually it is not feasible on thicknesses up to 6 mm and preferably is to be extended in diameter from 14 to 150 mm
Operation of direct hardening hardening artifacts cemented directly from the carburizing temperature.
WATER HARDENING Hardening carried out in water cooling medium.
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