Glossary A-G
Inviato: 30/01/2011, 10:16
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.
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.