Steel Classification

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Steel Classification

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Steel Classification

Messaggioda Aldebaran » 05/05/2010, 16:03

SAE-AISI
number
C Mn P max S max
(a) When silicon ranges or limits are required for bar and semifinished products, the values in Table 1 apply. For rods, the following ranges are
commonly used: 0.10 max; 0.07-0.15%; 0.10-0.20%; 0.15-0.35%; 0.20-0.40%; and 0.30-0.60%. Steels listed in this table can be produced
with additions of lead or boron. Leaded steels typically contain 0.15-0.35% Pb and are identified by inserting the letter L in the designation
(10L45); boron steels can be expected to contain 0.0005-0.003% B and are identified by inserting the letter B in the designation (10B46).
Low-carbon steels contain up to 0.30% C. The largest category of this class of steel is flat-rolled products (sheet or
strip) usually in the cold-rolled and annealed condition. The carbon content for these high-formability steels is very low,
less than 0.10% C, with up to 0.4% Mn. Typical uses are in automobile body panels, tin plate, and wire products.
For rolled steel structural plates and sections, the carbon content may be increased to approximately 0.30%, with higher
manganese up to 1.5%. These latter materials may be used for stampings, forgings, seamless tubes, and boiler plate.
Medium-carbon steels are similar to low-carbon steels except that the carbon ranges from 0.30 to 0.60% and the
manganese from 0.60 to 1.65%. Increasing the carbon content to approximately 0.5% with an accompanying increase in
manganese allows medium-carbon steels to be used in the quenched and tempered condition. The uses of medium carbonmanganese
steels include shafts, couplings, crankshafts, axles, gears, and forgings. Steels in the 0.40 to 0.60% C range are
also used for rails, railway wheels, and rail axles.
High-carbon steels contain from 0.60 to 1.00% C with manganese contents ranging from 0.30 to 0.90%. High-carbon
steels are used for spring materials and high-strength wires.
Ultrahigh-carbon steels are experimental alloys containing approximately 1.25 to 2.0% C. These steels are
thermomechanically processed to produce microstructures that consist of ultrafine, equiaxed grains of ferrite and a
uniform distribution of fine, spherical, discontinuous proeutectoid carbide particles (Ref 13). Such microstructures in
these steels have led to superplastic behavior (Ref 14). Properties of these experimental steels are described in Forming
and Forging, Volume 14 of ASM Handbook, formerly 9th Edition Metals Handbook (see the Appendix to the article
"Superplastic Sheet Forming," entitled "Superplasticity in Iron-Base Alloys").
References cited in this section
1. "Chemical Compositions of SAE Carbon Steels," SAE J403, 1989 SAE Handbook, Vol 1, Materials,
Society of Automotive Engineers, p 1.08-1.10
2. "Alloy, Carbon and High Strength Low Alloy Steels: Semifinished for Forging; Hot Rolled Bars and Cold
Finished Bars, Hot Rolled Deformed and Plain Concrete Reinforcing Bars," Steel Products Manual,
American Iron and Steel Institute, March 1986
3. "Plates; Rolled Floor Plates: Carbon, High Strength Low Alloy, and Alloy Steel," Steel Products Manual,
American Iron and Steel Institute, Aug 1985
12. Annual Statistical Report, American Iron and Steel Institute, 1988 (copyright 1989)
13. O.D. Sherby, B. Walser, C.M. Young, and E.M. Cady, Scr. Metall., Vol 9, 1975, p 569
14. T. Oyama, J. Wadsworth, M. Korchynsky, and O.D. Sherby, in Proceedings of the Fifth International
Conference on the Strength of Metals and Alloys, International Series on the Strength and Fracture of
Materials and Structures, Pergamon Press, 1980, p 381
16. "Chemical Compositions of SAE Alloy Steels," SAE J404, 1989 SAE Handbook, Vol 1, Materials, Society
of Automotive Engineers, p 1.10-1.12
17. "Potential Standard Steels," SAE J1081, 1989 SAE Handbook, Vol 1, Materials, Society of Automotive
Engineers, p 1.14-1.15
18. "High Strength Low Alloy Steel," SAE J310, 1989 SAE Handbook, Vol 1, Materials, Society of
Automotive Engineers, p 1.142-1.144
19. "Former SAE Standard and Former SAE EX-Steels," SAE J1249, 1989 SAE Handbook, Vol 1, Materials,
Society of Automotive Engineers, p 1.15-1.17
High-Strength Low-Alloy Steels
High-strength low-alloy (HSLA) steels, or microalloyed steels, are designed to provide better mechanical properties
and/or greater resistance to atmospheric corrosion than conventional carbon steels. They are not considered to be alloy
steels in the normal sense because they are designed to meet specific mechanical properties rather than a chemical
composition (HSLA steels have yield strengths of more than 275 MPa, or 40 ksi). The chemical composition of a specific
HSLA steel may vary for different product thickness to meet mechanical property requirements. The HSLA steels have
low carbon contents (0.50 to ~0.25% C) in order to produce adequate formability and weldability, and they have
manganese contents up to 2.0%. Small quantities of chromium, nickel, molybdenum, copper, nitrogen, vanadium,
niobium, titanium, and zirconium are used in various combinations.
The HSLA steels are commonly furnished in the as-rolled condition. They may also be supplied in a controlled-rolled,
normalized, or precipitation-hardened condition to meet specific property requirements. Primary applications for HSLA
steels include oil and gas line pipe, ships, offshore structures, automobiles, off-highway equipment, and pressure vessels.
HSLA Classification. The types of HSLA steels commonly used include (Ref 15):
· Weathering steels, designed to exhibit superior atmospheric corrosion resistance
· Control-rolled steels, hot rolled according to a predetermined rolling schedule designed to develop a
highly deformed austenite structure that will transform to a very fine equiaxed ferrite structure on
cooling
· Pearlite-reduced steels, strengthened by very fine-grain ferrite and precipitation hardening but with low
carbon content and therefore little or no pearlite in the microstructure
· Microalloyed steels, with very small additions (generally <0.10% each) of such elements as niobium,
vanadium, and/or titanium for refinement of grain size and/or precipitation hardening
· Acicular ferrite steel, very low carbon steels with sufficient hardenability to transform on cooling to a
very fine high-strength acicular ferrite (low-carbon bainite) structure rather than the usual polygonal
ferrite structure
· Dual-phase steels, processed to a micro-structure of ferrite containing small uniformly distributed
regions of high-carbon martensite, resulting in a product with low yield strength and a high rate of work
hardening, thus providing a high-strength steel of superior formability
The various types of HSLA steels may also have small additions of calcium, rare-earth elements, or zirconium for sulfide
inclusion shape control. Compositions, properties, and applications of these steels can be found in the articles "High-
Strength Structural and High-Strength Low-Alloy Steels," "Dual-Phase Steels," and "High-Strength Low-Alloy Steel
Forgings" in this Volume.
Reference cited in this section
15. L.F. Porter, High-Strength Low-Alloy Steels, in Encyclopedia of Materials Science and Engineering, MIT
Press, 1986, p 2157-2162
Low-Alloy Steels
Low-alloy steels constitute a category of ferrous materials that exhibit mechanical properties superior to plain carbon
steels as the result of additions of such alloying elements as nickel, chromium, and molybdenum. Total alloy content can
range from 2.07% up to levels just below that of stainless steels, which contain a minimum of 10% Cr. For many lowalloy
steels, the primary function of the alloying elements is to increase hardenability in order to optimize mechanical
properties and toughness after heat treatment. In some cases, however, alloy additions are used to reduce environmental
degradation under certain specified service conditions.
As with steels in general, low-alloy steels can be classified according to:
· Chemical composition, such as nickel steels, nickel-chromium steels, molybdenum steels, chromiummolybdenum
steels, and so on, as described in the section "SAE-AISI Designations" in this article and
as shown in Table 11
· Heat treatment, such as quenched and tempered, normalized and tempered, annealed, and so on
· Weldability, as described in the article "Weldability of Steels" in this Volume
Because of the wide variety of chemical compositions possible and the fact that some steels are used in more than one
heat-treated condition, some overlap exists among the alloy steel classifications. In this article, four major groups of alloy
steels are addressed: (1) low-carbon quenched and tempered (QT) steels, (2) medium-carbon ultrahigh-strength steels, (3)
bearing steels, and (4) heat-resistant chromium-molybdenum steels.
Low-carbon quenched and tempered steels combine high yield strength (from 350 to 1035 MPa, or 50 to 150
ksi) and high tensile strength with good notch toughness, ductility, corrosion resistance, or weldability. The various steels
have different combinations of these characteristics based on their intended applications. The chemical compositions of
typical QT low-carbon steels are given in Table 23. Many of the steels are covered by ASTM specifications. However, a
few steels, such as HY-80 and HY-100, are covered by military specifications. The steels listed are used primarily as
plate. Some of these steels, as well as other similar steels, are produced as forgings or castings. More detailed information
on low-carbon QT steels can be found in the articles "Hardenable Carbon and Low-Alloy Steels" and "High-Strength
Structural and High-Strength Low-Alloy Steels" in this Volume.
Medium-carbon ultrahigh-strength steels are structural steels with yield strengths that can exceed 1380 MPa
(200 ksi). Table 23 lists typical compositions. Many of these steels are covered by SAE-AISI designations or are
proprietary compositions. Product forms include billet, bar, rod, forgings, sheet, tubing, and welding wire. A review of the
heat treatments and resulting properties of these steels can be found in the article "Ultrahigh-Strength Steels" in this
Volume.
Bearing steels used for ball and roller bearing applications are comprised of low-carbon (0.10 to 0.20% C) casehardened
steels and high carbon (~1.0% C) through-hardened steels. Many of these steels are covered by SAEAISI
designations. Selection and properties of these materials are discussed in the article "Bearing Steels" in this Volume.
Chromium-molybdenum heat-resistant steels contain 0.5 to 9% Cr and 0.5 to 1.0% Mo. The carbon content is
usually below 0.20%. The chromium provides improved oxidation and corrosion resistance, and the molybdenum
increases strength at elevated temperatures. They are generally supplied in the normalized and tempered, quenched and
tempered, or annealed condition. Chromium-molybdenum steels are widely used in the oil and gas industries and in fossil
fuel and nuclear power plants. Various product forms and corresponding ASTM specifications for these steels are given
in Table 24. Nominal chemical compositions are provided in Table 25. High-temperature property data for chromiummolybdenum
steels are reviewed extensively in the article "Elevated-Temperature Properties of Ferritic Steels" in this
Volume.
Designations for Steels
A designation is the specific identification of each grade, type, or class of steel by a number, letter, symbol, name, or
suitable combination thereof unique to a particular steel. Grade, type, and class are terms used to classify steel products.
Within the steel industry, they have very specific uses: grade is used to denote chemical composition; type is used to
indicate deoxidation practice; and class is used to describe some other attribute, such as strength level or surface
smoothness.
In ASTM specifications, however, these terms are used somewhat interchangeably. In ASTM A 533, for example, type
denotes chemical composition, while class indicates strength level. In ASTM A 515, grade identifies strength level; the
maximum carbon content permitted by this specification depends on both plate thickness and strength level. In ASTM A
302, grade denotes requirements for both chemical composition and mechanical properties. ASTM A 514 and A 517 are
specifications for high-strength quenched and tempered plate for structural and pressure vessel applications, respectively;
each contains several compositions that can provide the required mechanical properties. However, A 514 type A has the
identical composition limits as A 517 grade. Additional information can be found in the section "ASTM (ASME)
Specifications" in this article.
Chemical composition is by far the most widely used basis for classification and/or designation of steels. The most
commonly used system of designation in the United States is that of the Society of Automotive Engineers (SAE) and the
American Iron and Steel Institute (AISI). The Unified Numbering System (UNS) is also being used with increasing
frequency. Each of these designation systems is described below.
SAE-AISI Designations
As stated above, the most widely used system for designating carbon and alloy steels is the SAE-AISI system. As a point
of technicality, there are two separate systems, but they are nearly identical and have been carefully coordinated by the
two groups. It should be noted, however, that AISI has discontinued the practice of designating steels. Therefore, the
reader should consult Volume 1, Materials, of the SAE Handbook for the most up-to-date information.
The SAE-AISI system is applied to semi-finished forgings, hot-rolled and cold-finished bars, wire road and seamless
tubular goods, structural shapes, plates, sheet, strip, and welded tubing. Table 11 summarizes the numerical designations
used in both SAE and AISI.
Carbon steels contain less than 1.65% Mn, 0.60% Si, and 0.60% Cu; they comprise the 1xxx groups in the SAE-AISI
system and are subdivided into four distinct series as a result of the difference in certain fundamental properties among
them. Plain carbon steels in the 10xx group are listed in Tables 12 and 13; note that ranges and limits of chemical
composition depend on the product form. Designations for merchant quality steels, given in Table 14, include the prefix
M. A carbon steel designation with the letter B inserted between the second and third digits indicates the steel contains
0.0005 to 0.003% B. Likewise, the letter L inserted between the second and third digits indicates that the steel contains
0.15 to 0.35% Pb for enhanced machinability. Resulfurized carbon steels in the 11xx group are listed in Table 15, and
resulfurized and rephosphorized carbon steels in the 12xx group are listed in Table 16. Both of these groups of steels are
produced for applications requiring good machinability. Tables 17 and 18 list steels having nominal manganese contents
of between 0.9 and 1.5% but no other alloying additions; these steels now have 15xx designations in place of the 10xx
designations formerly used.
Certain steels have hardenability requirements in addition to the limits and ranges of chemical composition. They are
distinguished from similar grades that have no hardenability requirement by the use of the suffix H. Limits and ranges of
chemical composition for all carbon steel products reflect the restrictions on heat and product analyses given in Tables 1,
2, and 5. Hardenability characteristics of carbon steels and the carbon and carbon-boron H steels are discussed in the
article "Hardenable Carbon and Low-Alloy Steels" in this Volume. Corresponding hardenability bands for these steels are
given in the article "Hardenability Curves". Except where indicated, all of these designations for carbon steels are both
AISI and SAE designations.
Alloy steels contain manganese, silicon, or copper in quantities greater than those listed for the carbon steels, or they
have specified ranges or minimums for one or more of the other alloying elements. In the AISI-SAE system of
designations, the major alloying elements in a steel are indicated by the first two digits of the designation (Table 11). The
amount of carbon, in hundredths of a percent, is indicated by the last two (or three) digits. The chemical compositions of
AISI-SAE standard grades of alloy steels are given in Table 19. For alloy steels that have specific hardenability
requirements, the suffix H is used to distinguish these steels from corresponding grades that have no hardenability
requirement (see the article "Hardenable Carbon and Low-Alloy Steels" in this Volume for chemical compositions of
alloy H steels). As with carbon steels, the letter B inserted between the second and third digits indicates that the steel
contains boron. The prefix E signifies that the steel was produced by the electric furnace process. Limits and ranges of
chemical composition for all alloy steel products reflect the restrictions on heat and product analyses given in Tables 1
through 7. The designations in Table 19 are both AISI and SAE designations unless otherwise indicated.
Potential standard steels are listed in SAE J1081 and Table 20. These are experimental grades to which no regular
AISI-SAE designations have been assigned. Some were developed to minimize the nickel content; others were devised to
improve a particular attribute of a standard grade of alloy steel.
HSLA Steels. Several grades of HSLA steel are described in SAE Recommended Practice J410; their chemical
compositions and minimum mechanical properties are listed in Table 21. These steels have been developed as a
compromise between the convenient fabrication characteristics and low cost of plain carbon steels and the high strength
of heat-treated alloy steels. These steels have excellent strength and ductility as-rolled.
Formerly Listed SAE Steels. A number of grades of carbon and alloy steels have been deleted from the list of SAE
standard steels due to lack of use. For the convenience of those who might encounter an application for one of these
grades, they are listed in Table 22.
UNS Designations
The Unified Numbering System (UNS) has been developed by ASTM and SAE and several other technical societies,
trade associations, and United States government agencies. A UNS number, which is a designation of chemical
composition and not a specification, is assigned to each chemical composition of a metallic alloy. Available UNS
designation are included in the tables in this article.
The UNS designation of an alloy consists of a letter and five numerals. The letters indicate the broad class of alloys; the
numerals define specific alloys within that class. Existing designation systems, such as the AISI-SAE system for steels,
have been incorporated into UNS designations. UNS is described in greater detail in SAE J1086 and ASTM E 527.
AMS Designations
Aerospace Materials Specifications (AMS), published by SAE, are complete specifications that are generally adequate for
procurement purposes. Most of the AMS designations pertain to materials intended for aerospace applications; the
specifications may include mechanical property requirements significantly more severe than those for grades of steel
having similar compositions but intended for other applications. Processing requirements, such as for consumable
electrode remelting, are common in AMS steels. Chemical compositions for AMS grades of carbon and alloy steels are
given in Tables 26 and 27, respectively.
Specifications for Steels
A specification is a written statement of the requirements, both technical and commercial, that a product must meet; it is a
document that controls procurement. There are nearly as many formats for specifications as there are groups writing them,
but any reasonably adequate specification will provide information about the items listed below:
· Scope may cover product classification, including size range when necessary, condition, and any
comments on product processing deemed helpful to either the supplier or user. An information title plus
a statement of the required form may be used instead of a scope clause
· Chemical composition may be detailed, or it may be indicated by a well-recognized designation based
on chemical composition. The SAE-AISI designations are frequently used
· The quality statement includes any appropriate quality descriptor and whatever additional requirements
might be necessary. It may also include the type of steel and the steelmaking processes permitted
· Quantitative requirements identify allowable ranges of the composition properties and all physical and
mechanical properties necessary to characterize the material. Test methods used to determine these
properties should also be included, at least by reference to standard test methods. For reasons of
economy, this section should be limited to those properties that are germane to the intended application
· Additional requirements can include special tolerances, surface preparation, and edge finish on flatrolled
products, as well as special identification, packaging, and loading instructions
Engineering societies, associations, and institutes whose members make, specify, or purchase steel products publish
standard specifications, many of which have become well known and highly respected. Some of the important
specification-writing groups are listed below. It is obvious from the names of some of these that the specifications
prepared by a particular group may be limited to its own specialized field:
ASTM (ASME) Specifications
The most widely used standard specifications for steel products in the United States are those published by ASTM. These
are complete specifications, generally adequate for procurement purposes. Many ASTM specifications apply to specific
products, such as A 574 for alloy steel socket head cap screws. These specifications are generally oriented toward
performance of the fabricated end product, with considerable latitude in chemical composition of the steel used to make
the end product.
ASTM specifications represent a consensus among producers, specifiers, fabricators, and users of steel mill products. In
many cases, the dimensions, tolerances, limits, and restrictions in the ASTM specifications are similar to or the same as
the corresponding items of the standard practices in the AISI Steel Products Manuals. Many of the ASTM specifications
have been adopted by the American Society of Mechanical Engineers (ASME) with little or no modification; ASME uses
the prefix S and the ASTM designation for these specifications. For example, ASME-SA213 and ASTM A 213 are
identical.
Steel products can be identified by the number of the ASTM specification to which they are made. The number consists
of the letter A (for ferrous materials) and an arbitrary, serially assigned number. Citing the specification number,
however, is not always adequate to completely describe a steel product. For example, A 434 is the specification for heattreated
(hardened and tempered) alloy steel bars. To completely describe steel bars indicated by this specification, the
grade (SAE-AISI designation in this case) and class (required strength level) must also be indicated. The ASTM
specification A 434 also incorporates, by reference, two standards for test methods (A 370 for mechanical testing and E
112 for grain size determination) and A 29, which specifies the general requirements for bar products.
SAE-AISI designations for the compositions of carbon and alloy steels are sometimes incorporated into the ASTM
specifications for bars, wires, and billets for forging. Some ASTM specifications for sheet products include SAE-AISI
designations for composition. The ASTM specifications for plates and structural shapes generally specify the limits and
ranges of chemical composition directly, without the SAE-AISI designations. Table 28 includes a list of some of the
ASTM specifications that incorporate AISI-SAE designations for compositions of the different grades of steel
International Designations and Specifications
The steel industry has undergone major changes during the past 15 to 20 years. No longer is the international steel
marketplace dominated by the United States. In fact, the steel produced in all of North America accounts for less than
14% of total world production. The distribution of steel production among various nations is illustrated in Fig. 3;
production figures are given in Table 30. With continuing advances in production by third world developing countries
(Fig. 4), the international steel marketplace will continue to experience substantial changes during the 1990s.
AFNOR standards are developed by the Association Francaise de Normalisation in Paris, France. The correct format
for reporting AFNOR standards, which are listed in Tables 31, 38, and 39, is a follows. An uppercase NF is placed to the
left of the alphanumeric code. This code consists of an uppercase letter followed by a series of digits, which are
subsequently followed by an alphanumeric sequence. For example, as indicated in Tables 31 and 38, NF A35-562 35MF6
is a resulfurized (free-cutting) steel with the following composition:
UNI standards are developed by the Ente Nazionale Italiano di Unificazione in Milan, Italy. Italian standards are
preceded by the uppercase letters UNI followed by a four-digit product form code subsequently followed by an
alphanumeric alloy identification (Tables 31, 40, and 41). For example, as indicated in Tables 31 and 40, UNI 5598 3CD5
is a low-carbon steel used for wire rod with the following composition:
Swedish standards (SS14) are prepared by the Swedish Standards Institution in Stockholm. Designations begin with
the letters SS followed by the number 14 (all Swedish carbon and low-alloy steels are covered by SS14). What
subsequently follows is a four-digit numerical sequence similar to the German Werkstoff number. Swedish designations
are listed in Tables 31, 42, and 43.
References cited in this section
12. Annual Statistical Report, American Iron and Steel Institute, 1988 (copyright 1989)
20. D.L. Potts and J.G Gensure, International Metallic Materials Cross-Reference, Genium Publishing, 1989
21. C.W. Wegst, Stahlschlüssel (Key to Steel), Verlag Stahlschlüssel Wegst GmbH, 1989
References
1. "Chemical Compositions of SAE Carbon Steels," SAE J403, 1989 SAE Handbook, Vol 1, Materials,
Society of Automotive Engineers, p 1.08-1.10
2. "Alloy, Carbon and High Strength Low Alloy Steels: Semifinished for Forging; Hot Rolled Bars and Cold
Finished Bars, Hot Rolled Deformed and Plain Concrete Reinforcing Bars," Steel Products Manual,
American Iron and Steel Institute, March 1986
3. "Plates; Rolled Floor Plates: Carbon, High Strength Low Alloy, and Alloy Steel," Steel Products Manual,
American Iron and Steel Institute, Aug 1985
4. "Standard Specification for General Requirements for Rolled Steel Plates, Shapes, Sheet Piling, and Bars
for Structural Use," ASTM A 6/A 6M, American Society for Testing and Materials
5. The Making, Shaping and Treating of Steel, 10th ed., United States Steel Corporation, 1985
6. "Carbon and Alloy Steels," SAE J411, 1989 SAE Handbook, Vol 1, Materials, Society of Automotive
Engineers, p 2.01-2.03
7. G. Krauss, Steels--Heat Treatment and Processing Principals, ASM INTERNATIONAL, 1989
8. W.C. Leslie, The Physical Metallurgy of Steels, McGraw-Hill, 1981
9. E.C. Bain and H.W. Paxton, Alloying Elements in Steel, American Society for Metals, 1966
10. A.K. Sinha, Ferrous Physical Metallurgy, Butterworths, 1989
11. R.W.K. Honeycombe, Steels--Microstructure and Properties, Edward Arnold Ltd., 1982
12. Annual Statistical Report, American Iron and Steel Institute, 1988 (copyright 1989)
13. O.D. Sherby, B. Walser, C.M. Young, and E.M. Cady, Scr. Metall., Vol 9, 1975, p 569
14. T. Oyama, J. Wadsworth, M. Korchynsky, and O.D. Sherby, in Proceedings of the Fifth International
Conference on the Strength of Metals and Alloys, International Series on the Strength and Fracture of
Materials and Structures, Pergamon Press, 1980, p 381
15. L.F. Porter, High-Strength Low-Alloy Steels, in Encyclopedia of Materials Science and Engineering, MIT
Press, 1986, p 2157-2162
16. "Chemical Compositions of SAE Alloy Steels," SAE J404, 1989 SAE Handbook, Vol 1, Materials,
Society of Automotive Engineers, p 1.10-1.12
17. "Potential Standard Steels," SAE J1081, 1989 SAE Handbook, Vol 1, Materials, Society of Automotive
Engineers, p 1.14-1.15
18. "High Strength Low Alloy Steel," SAE J310, 1989 SAE Handbook, Vol 1, Materials, Society of
Automotive Engineers, p 1.142-1.144
19. "Former SAE Standard and Former SAE EX-Steels," SAE J1249, 1989 SAE Handbook, Vol 1, Materials,
Society of Automotive Engineers, p 1.15-1.17
20. D.L. Potts and J.G Gensure, International Metallic Materials Cross-Reference, Genium Publishing, 1989
21. C.W. Wegst, Stahlschlüssel (Key to Steel), Verlag Stahlschlüssel Wegst GmbH, 1989
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