ASTM A508/A508M-05b(2010)
(Specification)Standard Specification for Quenched and Tempered Vacuum-Treated Carbon and Alloy Steel Forgings for Pressure Vessels
Standard Specification for Quenched and Tempered Vacuum-Treated Carbon and Alloy Steel Forgings for Pressure Vessels
ABSTRACT
This specification covers quenched and tempered vacuum-treated carbon and alloy steel forgings for pressure vessels, such as those used in reactor systems, specifically, vessel closures, shells, flanges, tube sheets, rings, heads, and similar parts. Steels shall be manufactured by basic electric-furnace process except when secondary ladle refining or remelting process is employed, and shall be vacuum treated prior to or during the pouring of the ingot. Materials shall also go through preliminary heat treatment and quenching for mechanical properties. Heat and product analyses shall be executed to evaluate the conformance of the forgings with specified chemical requirements. Tension and Charpy impact tests shall also be performed to examine the conformance of steel specimens with the following mechanical properties: tensile strength, yield strength, elongation, and reduction of area. Nondestructive inspection procedures, such as magnetic particle examination, and longitudinal wave and angle beam ultrasonic examination, shall also be carried out. Repair welding may be permitted at the option of the purchaser.
SCOPE
1.1 This specification covers quenched and tempered vacuum-treated carbon and alloy steel forgings for pressure vessels such as those used in reactor systems. Specifically, it covers forgings for vessel closures, shells, flanges, tube sheets, rings, heads, and similar parts.
1.2 All grades are considered weldable under proper conditions. Welding technique is of fundamental importance, and it is presupposed that welding procedure and inspection will be in accordance with approved methods for the grade of material used.
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
1.4 Unless the order specifies the applicable “M” specification designation, the material shall be furnished to the inch-pound units.
Note 1—Grades 1 and 1A are composed of different chemistries but have the same mechanical requirements.
General Information
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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation:A508/A508M −05b(Reapproved 2010)
Standard Specification for
Quenched and Tempered Vacuum-Treated Carbon and Alloy
Steel Forgings for Pressure Vessels
This standard is issued under the fixed designationA508/A508M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope
Grade 5 Class 2 Class 5A
Grade 22 Class 3 Class 22B
1.1 This specification covers quenched and tempered
Grade 22 Classes 4, 5, 6, and
vacuum-treated carbon and alloy steel forgings for pressure 7
Grade 3V Class 3V
vessels such as those used in reactor systems. Specifically, it
covers forgings for vessel closures, shells, flanges, tube sheets, 1.5 This standard does not purport to address all of the
rings, heads, and similar parts.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
1.2 All grades are considered weldable under proper condi-
priate safety and health practices and determine the applica-
tions. Welding technique is of fundamental importance, and it
bility of regulatory limitations prior to use.
ispresupposedthatweldingprocedureandinspectionwillbein
accordance with approved methods for the grade of material
2. Referenced Documents
used.
2.1 ASTM Standards:
1.3 The values stated in either SI units or inch-pound units
A275/A275M Practice for Magnetic Particle Examination of
are to be regarded separately as standard. The values stated in
Steel Forgings
each system may not be exact equivalents; therefore, each
A370 Test Methods and Definitions for Mechanical Testing
system shall be used independently of the other. Combining
values from the two systems may result in non-conformance of Steel Products
A388/A388M Practice for Ultrasonic Examination of Steel
with the standard.
Forgings
1.4 Unless the order specifies the applicable “M” specifica-
A788/A788M Specification for Steel Forgings, General Re-
tion designation, the material shall be furnished to the inch-
quirements
pound units.
A966/A966M Practice for Magnetic Particle Examination of
NOTE 1—Grades 1 and 1A are composed of different chemistries but
Steel Forgings Using Alternating Current
have the same mechanical requirements.
E208 Test Method for Conducting Drop-Weight Test to
NOTE 2—Designations have been changed as follows:
Determine Nil-Ductility Transition Temperature of Fer-
Current Formerly
ritic Steels
Grade 1 Class 1
Grade 1A Class 1A E428 Practice for Fabrication and Control of Metal, Other
Grade 2 Class 1 Class 2
than Aluminum, Reference Blocks Used in Ultrasonic
Grade 2 Class 2 Class 2A
Testing
Grade 3 Class 1 Class 3
Grade 3 Class 2 Class 3A
2.2 American Society of Mechanical Engineers Standard:
Grade 4N Class 1 Class 4
Grade 4N Class 2 Class 4A
Boiler and Pressure Vessel Code—Section III, Articles
Grade 4N Class 3 Class 4B
NB 2300, NC 2300, ND 2300, NE 2300, NF 2300, NG
Grade 5 Class 1 Class 5
This specification is under the jurisdiction ofASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee For referenced ASTM standards, visit the ASTM website, www.astm.org, or
A01.06 on Steel Forgings and Billets. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved April 1, 2010. Published May 2010. Originally Standards volume information, refer to the standard’s Document Summary page on
approved in 1964. Last previous edition approved in 2005 as A508/A508M – 05b. the ASTM website.
DOI: 10.1520/A0508_A0508M-05BR10. Available from American Society of Mechanical Engineers (ASME), ASME
For ASME Boiler and Pressure Vessel Code applications see related Specifi- International Headquarters, Three Park Ave., New York, NY 10016-5990, http://
cation SA-508/SA-508M in Section II of that Code. www.asme.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A508/A508M−05b (2010)
3. Ordering Information 4.1.2 The molten steel shall be vacuum treated in accor-
dance with the methods described in Specification A788/
3.1 Purchase Order—In addition to the ordering informa-
A788M, prior to or during the pouring of the ingot, in order to
tion required by Specification A788/A788M, the purchaser
remove objectionable gases, particularly hydrogen.
shall include with the inquiry and order a detailed drawing that
Grade 22 Classes 4, 5, 6, and 7 liquid steel shall be produced
locates the areas of significant loading in the forging (when
to a fine grain melting practice which has been shown to result
required), the method of selecting test locations (see 6.1.5 and
in a prior austenitic grain size of five or finer.
6.1.6), and purchase options (see 4.2.2, 6.2, and 10.1) and any
4.1.3 Discard—Sufficient discard shall be made from each
supplementary requirements desired.
ingottosecurefreedomfrompipingandexcessivesegregation.
3.2 Forging Drawing—Each forging shall be manufactured
4.2 Heat Treatment:
in accordance with a purchaser-approved drawing showing the
4.2.1 Preliminary Heat Treatment—After forging and be-
prequenched dimensions, the finished dimensions, the surfaces
fore reheating, the forgings shall be cooled to provide substan-
that will be subjected to significant loading, and the locations
tially complete transformation of austenite. Preliminary heat
of mechanical test specimens.
treatment may be applied to improve machinability and to
3.3 Material supplied to this specification shall conform to
enhance subsequent heat treatments.
the requirements of Specification A788/A788M, which out-
4.2.2 Heat Treatment for Mechanical Properties—The forg-
lines additional ordering information, manufacturing
ings shall be heated to a temperature which produces an
requirements, testing and retesting methods and procedures,
austenitic structure and then quenched in a suitable liquid
marking, certification, product analysis variations, and addi-
medium by spraying or immersion. For Grade 4N, Classes 1
tional supplementary requirements.
and 3, the austenitizing temperature shall be 1540°F [840°C]
3.3.1 When specified by the purchaser, it is permissible to
min to 1640°F [895°C] max. Quenching shall be followed by
perform Magnetic particle examination using the AC yoke in
tempering at a subcritical temperature and holding at this
accordance with Test Method A966/A966M instead of using
temperature for a minimum time of one-half hour per inch of
Test Method A275/A275M (see 8.2.1).
maximum section thickness. Except when Supplementary Re-
3.4 The optional minimum silicon content as expressed in quirement S 13 is specified for Grades 2 and 3, the minimum
tempering temperatures shall be as follows:
Footnote B to Table 1, if required.
Grades 1, 1A, 2 Class 2, and 3 Class 2 1150°F [620°C]
3.5 If the requirements of this specification are in conflict
Grades 2 Class 1 and 3 Class 1 1200°F [650°C]
with the requirements of Specification A788/A788M, the
Grades 4N Classes 1 and 2, and 5 1100°F [595°C]
requirements of this specification shall prevail. Classes 1 and 2
Grade 4N Class 3 1125°F [605°C]
Grades 3V and 3VCb 1250°F [675°C]
4. Materials and Manufacture
Grade 22, Class 3 1200°F [650°C]
Grade 22, Classes 4, 5, 6, and 7 1100°F [593°C]
4.1 Melting Process:
Specific cooling rates from the tempering temperature shall
4.1.1 The steel shall be made by the basic electric-furnace
be applied if Supplementary Requirement S14 is specified.
process except when secondary ladle refining or the remelting
process is employed, in which case the melting processes of 4.3 For Grades 1, 1A, 2, 2A, 3, or 3A, a multiple stage
Specification A788/A788M are permitted. austenitizing procedure may be used whereby the forging is
TABLE 1 Chemical Requirements
Composition, %
A
Grade 1 Grade 1A Grade 2 Grade 3 Grade 4N Grade 5 Grade 22 Grade 3V Grade 3VCb Grade 6
Carbon 0.35 max 0.30 max 0.27 max 0.25 max 0.23 max 0.23 max 0.11–0.15 0.10–0.15 0.10–0.15 0.28–0.33
Manganese 0.40–1.05 0.70–1.35 0.50–1.00 1.20–1.50 0.20–0.40 0.20–0.40 0.30–0.60 0.30–0.60 0.30–0.60 0.75–1.15
Phosphorus 0.025 max 0.025 max 0.025 max 0.025 max 0.020 max 0.020 max 0.015 max 0.020 max 0.020 max 0.025 max
Sulfur 0.025 max 0.025 max 0.025 max 0.025 max 0.020 max 0.020 max 0.015 max 0.020 max 0.010 max 0.025 max
B
Silicon 0.40 max 0.40 max 0.40 max 0.40 max 0.40 max 0.30 max 0.35 max 0.10 max 0.10 max 0.35 max
Nickel 0.40 max 0.40 max 0.50–1.00 0.40–1.00 2.8–3.9 2.8–3.9 0.25 max . . . 0.25 max 0.75–0.95
Chromium 0.25 max 0.25 max 0.25–0.45 0.25 max 1.50–2.00 1.50–2.00 2.00–2.50 2.8–3.3 2.7–3.3 0.70–1.00
Molybdenum 0.10 max 0.10 max 0.55–0.70 0.45–0.60 0.40–0.60 0.40–0.60 0.90–1.10 max 0.90–1.10 0.90–1.10 0.30–0.45
Vanadium 0.05 max 0.05 max 0.05 max 0.05 max 0.03 max 0.08 max 0.02 max 0.20–0.30 0.20–0.30 0.05 max
Columbium 0.01 max 0.01 max 0.01 max 0.01 max 0.01 max 0.01 max 0.01 max 0.01 max 0.015–0.070 0.01 max
Copper 0.20 max 0.20 max 0.20 max 0.20 max 0.25 max 0.25 max 0.25 max 0.25 max 0.25 max 0.25 max
Calcium 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.0005–0.0150 0.015 max
Boron 0.003 max 0.003 max 0.003 max 0.003 max 0.003 max 0.003 max 0.003 max 0.001–0.003 0.003 max 0.003 max
Titanium 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.015–0.035 0.015 max 0.015 max
C
Aluminum 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.015 max 0.015 max 0.025 max
A
For Grade 22 Classes 5, 6, and 7 with section thickness at heat treat of 8 in. or greater, the carbon and manganese shall be held to 0.13 to 0.15 and 0.50 to 0.60,
respectively.
B
When required by the purchaser a minimum silicon content of 0.15 % shall apply for Grades 1, 1A, 2, 3, and 4N.
C
Aluminum content reported shall be the combined total soluble and insoluble aluminum.
A508/A508M−05b (2010)
first fully austenitized and liquid quenched, followed by [2032mm]orLess—Atestprolongationshallbelocatedatone
reheating within the intercritical temperature range to partially end. Two tension test specimens shall be taken from the test
reaustenitize and again liquid quenched. On completion of the prolongation and shall be oriented 180° apart.
austenitizing/quenching cycles, the forgings shall be tempered 6.1.2.5 Forgings or Multiple Forgings with Rough Ma-
at a subcritical temperature as described in 4.2.2.
chined Weights Over 10000 lb [4540 kg] and Having a
Heat-TreatedLength(ExclusiveofTestProlongations)Exceed-
5. Chemical Composition
ing 80 in. [2032 mm]—A test prolongation shall be located at
each end. The tension test specimens oriented 180° apart from
5.1 Heat Analysis—The heat analysis obtained from sam-
each other shall be taken from each test prolongation. The two
pling in accordance with Specification A788/A788M shall
tension specimens located in one test prolongation shall be
comply with Table 1 except that the additional features of
oriented 90° in relation to the two tension specimens located in
Supplementary Requirements S7, S8, S9, and S11 shall also
the other test prolongation.
apply as individually specified in the ordering information.
NOTE 3—Multiple forgings in 6.1.2.2 through 6.1.2.5 are those which
5.2 ProductAnalysis—The manufacturer shall use the prod-
will be separated after the quench and temper treatment.
uct analysis provision of Specification A788/A788M to obtain
NOTE 4—A test prolongation is defined as that integral test metal
a product analysis from a forging representing each heat or
located at an end of the forging or forging multiples.
multiple heat. The permissible variations provided in the table
6.1.3 Samples for mechanical test specimen shall be re-
on Permissible Variations in Product Analysis for Killed Steel
moved from forgings after the quenching and tempering heat
in Specification A788/A788M apply for manganese, nickel,
treatment. The sample material shall be subjected to a simu-
chromium, molybdenum, and vanadium only. Boron is not
lated post weld heat treatment if Supplementary Requirement
subject to product analysis. The purchaser may also make this
S1 is specified.
determination in accordance with Specification A788/A788M.
6.1.4 For upset disk forgings, the longitudinal axis of the
test specimens shall be in the tangential direction. For all other
6. Mechanical Properties
parts, the longitudinal axis of the specimens shall be parallel to
6.1 Tension Test:
the direction of major working of the forging.
6.1.1 ThesteelshallconformtotherequirementsofTable2.
6.1.5 Each forging shall be manufactured in accordance
6.1.2 The location and number of tension test specimens for
with a purchaser-approved drawing, showing the prequenched
each forging or multiple forging shall be as follows:
dimensions, the finished dimensions, the surfaces that will be
6.1.2.1 Multiple Forgings Separated into Identical Indi-
subjected to critical stresses, and the location of mechanical
vidual Forgings with Rough Machined Weights not Exceeding
test specimens.
1000 lb [455 kg] Prior to Quenching and Tempering
6.1.6 The tension test specimens shall be positioned so that
Treatment—At least one individual forging from each multiple
the longitudinal axis and mid-length is in accordance with one
forging in each heat-treating lot shall be tested using the test
of the following methods:
specimen locations of 6.1.5 or 6.1.6 as specified on the
6.1.6.1 Method 1—t by 2t, where t is the distance from the
purchase orders, except that test specimens located at mid-
area of significant loading (see 3.1) to the nearest quenched
length may be closer to the ends of the production forging than
surface. However, they shall not be nearer to one quenched
the specified distance to the second surfaces.All forgings shall
surfacethan ⁄4in.[20mm]andtothesecondquenchedsurface
be quenched and tempered in the same furnace charge. All
than 1 ⁄2 in. [40 mm].
forgingsfromthemultipleshallbeBrinellhardnesstestedafter
6.1.6.2 Method 2— ⁄4 T by T , where T is the maximum
heat treatment and forgings not tested for mechanical proper-
thickness of the forging as heat treated. Where this method of
ties shall have a Brinell Hardness within 20 points of the
testing is employed, the following limitations for as-treated
Brinell Hardness of the forging that has been tested for
thickness shall generally apply:
mechanical properties.
Grades 1 and 1a 3 in. [75 mm], max
6.1.2.2 Forgings or Multiple Forgings (Note 3) with Rough
Grades 2 Class 2 and 3
...
This document is not anASTM standard and is intended only to provide the user of anASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation:A508/A508M–05b Designation: A508/A508M – 05b (Reapproved 2010)
Standard Specification for
Quenched and Tempered Vacuum-Treated Carbon and Alloy
Steel Forgings for Pressure Vessels
This standard is issued under the fixed designationA508/A508M; the number immediately following the designation indicates the year
of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope *
1.1 This specification covers quenched and tempered vacuum-treated carbon and alloy steel forgings for pressure vessels such
as those used in reactor systems. Specifically, it covers forgings for vessel closures, shells, flanges, tube sheets, rings, heads, and
similar parts.
1.2 All grades are considered weldable under proper conditions. Welding technique is of fundamental importance, and it is
presupposed that welding procedure and inspection will be in accordance with approved methods for the grade of material used.
1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each
system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the
two systems may result in non-conformance with the standard.
1.4 Unless the order specifies the applicable “M” specification designation, the material shall be furnished to the inch-pound
units.
NOTE 1—Grades 1 and 1A are composed of different chemistries but have the same mechanical requirements.
NOTE 2—Designations have been changed as follows:
Current Formerly
Grade 1 Class 1
Grade 1A Class 1A
Grade 2 Class 1 Class 2
Grade 2 Class 2 Class 2A
Grade 3 Class 1 Class 3
Grade 3 Class 2 Class 3A
Grade 4N Class 1 Class 4
Grade 4N Class 2 Class 4A
Grade 4N Class 3 Class 4B
Grade 5 Class 1 Class 5
Grade 5 Class 2 Class 5A
Grade 22 Class 3 Class 22B
Grade 22 Classes 4, 5, 6, and
Grade 3V Class 3V
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
2. Referenced Documents
2.1 ASTM Standards:
A275/A275M Practice for Magnetic Particle Examination of Steel Forgings
A370 Test Methods and Definitions for Mechanical Testing of Steel Products
A388/A388M Practice for Ultrasonic Examination of Steel Forgings
A788/A788M Specification for Steel Forgings, General Requirements
This specification is under the jurisdiction ofASTM CommitteeA01 on Steel, Stainless Steel,Steel and RelatedAlloys and is the direct responsibility of Subcommittee
A01.06 on Steel Forgings and Billets.
Current edition approved Oct.April 1, 2005.2010. Published October 2005.May 2010. Originally approved in 1964. Last previous edition approved in 2005 as
A508/A508M – 05ab. DOI: 10.1520/A0508_A0508M-05BR10.
For ASME Boiler and Pressure Vessel Code applications see related Specification SA-508/SA-508M in Section II of that Code.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. ForAnnualBookofASTMStandards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A508/A508M – 05b (2010)
A966/A966M Practice for Magnetic Particle Examination of Steel Forgings Using Alternating Current
E208 Test Method for Conducting Drop-Weight Test to Determine Nil-Ductility Transition Temperature of Ferritic Steels
E428 Practice for Fabrication and Control of Metal, Other than Aluminum, Reference Blocks Used in Ultrasonic Testing
2.2 American Society of Mechanical Engineers Standard:
Boiler and Pressure Vessel Code—Section III, Articles NB 2300, NC 2300, ND 2300, NE 2300, NF 2300, NG 2300
3. Ordering Information
3.1 Purchase Order—In addition to the ordering information required by Specification A788/A788M, the purchaser shall
include with the inquiry and order a detailed drawing that locates the areas of significant loading in the forging (when required),
the method of selecting test locations (see 6.1.5 and 6.1.6), and purchase options (see 4.2.2, 6.2, and 10.1) and any supplementary
requirements desired.
3.2 Forging Drawing—Each forging shall be manufactured in accordance with a purchaser-approved drawing showing the
prequenched dimensions, the finished dimensions, the surfaces that will be subjected to significant loading, and the locations of
mechanical test specimens.
3.3 Material supplied to this specification shall conform to the requirements of Specification A788/A788M, which outlines
additional ordering information, manufacturing requirements, testing and retesting methods and procedures, marking, certification,
product analysis variations, and additional supplementary requirements.
3.3.1 When specified by the purchaser, it is permissible to perform Magnetic particle examination using the AC yoke in
accordance with Test Method A966/A966M instead of using Test Method A275/A275M (see 8.2.1).
3.4 The optional minimum silicon content as expressed in Footnote B to Table 1, if required.
3.5 IftherequirementsofthisspecificationareinconflictwiththerequirementsofSpecificationA788/A788M,therequirements
of this specification shall prevail.
4. Materials and Manufacture
4.1 Melting Process:
4.1.1 Thesteelshallbemadebythebasicelectric-furnaceprocessexceptwhensecondaryladlerefiningortheremeltingprocess
is employed, in which case the melting processes of Specification A788/A788M are permitted.
4.1.2 The molten steel shall be vacuum treated in accordance with the methods described in SpecificationA788/A788M, prior
to or during the pouring of the ingot, in order to remove objectionable gases, particularly hydrogen.
Grade 22 Classes 4, 5, 6, and 7 liquid steel shall be produced to a fine grain melting practice which has been shown to result
in a prior austenitic grain size of five or finer.
4.1.3 Discard—Sufficient discard shall be made from each ingot to secure freedom from piping and excessive segregation.
4.2 Heat Treatment:
4.2.1 Preliminary Heat Treatment—After forging and before reheating, the forgings shall be cooled to provide substantially
complete transformation of austenite. Preliminary heat treatment may be applied to improve machinability and to enhance
subsequent heat treatments.
Available from American Society of Mechanical Engineers, 345 E. 47th St., New York, NY 10017.
Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Three Park Ave., New York, NY 10016-5990, http://
www.asme.org.
TABLE 1 Chemical Requirements
Composition, %
A
Grade 1 Grade 1A Grade 2 Grade 3 Grade 4N Grade 5 Grade 22 Grade 3V Grade 3VCb Grade 6
Carbon 0.35 max 0.30 max 0.27 max 0.25 max 0.23 max 0.23 max 0.11–0.15 0.10–0.15 0.10–0.15 0.28–0.33
Manganese 0.40–1.05 0.70–1.35 0.50–1.00 1.20–1.50 0.20–0.40 0.20–0.40 0.30–0.60 0.30–0.60 0.30–0.60 0.75–1.15
Phosphorus 0.025 max 0.025 max 0.025 max 0.025 max 0.020 max 0.020 max 0.015 max 0.020 max 0.020 max 0.025 max
Sulfur 0.025 max 0.025 max 0.025 max 0.025 max 0.020 max 0.020 max 0.015 max 0.020 max 0.010 max 0.025 max
B
Silicon 0.40 max 0.40 max 0.40 max 0.40 max 0.40 max 0.30 max 0.35 max 0.10 max 0.10 max 0.35 max
Nickel 0.40 max 0.40 max 0.50–1.00 0.40–1.00 2.8–3.9 2.8–3.9 0.25 max . . . 0.25 max 0.75–0.95
Chromium 0.25 max 0.25 max 0.25–0.45 0.25 max 1.50–2.00 1.50–2.00 2.00–2.50 2.8–3.3 2.7–3.3 0.70–1.00
Molybdenum 0.10 max 0.10 max 0.55–0.70 0.45–0.60 0.40–0.60 0.40–0.60 0.90–1.10 max 0.90–1.10 0.90–1.10 0.30–0.45
Vanadium 0.05 max 0.05 max 0.05 max 0.05 max 0.03 max 0.08 max 0.02 max 0.20–0.30 0.20–0.30 0.05 max
Columbium 0.01 max 0.01 max 0.01 max 0.01 max 0.01 max 0.01 max 0.01 max 0.01 max 0.015–0.070 0.01 max
Copper 0.20 max 0.20 max 0.20 max 0.20 max 0.25 max 0.25 max 0.25 max 0.25 max 0.25 max 0.25 max
Calcium 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.0005–0.0150 0.015 max
Boron 0.003 max 0.003 max 0.003 max 0.003 max 0.003 max 0.003 max 0.003 max 0.001–0.003 0.003 max 0.003 max
Titanium 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.015 max 0.015–0.035 0.015 max 0.015 max
C
Aluminum 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.015 max 0.015 max 0.025 max
A
For Grade 22 Classes 5, 6, and 7 with section thickness at heat treat of 8 in. or greater, the carbon and manganese shall be held to 0.13 to 0.15 and 0.50 to 0.60,
respectively.
B
When required by the purchaser a minimum silicon content of 0.15 % shall apply for Grades 1, 1A, 2, 3, and 4N.
C
Aluminum content reported shall be the combined total soluble and insoluble aluminum.
A508/A508M – 05b (2010)
4.2.2 Heat Treatment for Mechanical Properties—The forgings shall be heated to a temperature which produces an austenitic
structureandthenquenchedinasuitableliquidmediumbysprayingorimmersion.ForGrade4N,Classes1and3,theaustenitizing
temperature shall be 1540°F [840°C] min to 1640°F [895°C] max. Quenching shall be followed by tempering at a subcritical
temperature and holding at this temperature for a minimum time of one-half hour per inch of maximum section thickness. Except
when Supplementary Requirement S 13 is specified for Grades 2 and 3, the minimum tempering temperatures shall be as follows:
Grades 1, 1A, 2 Class 2, and 3 Class 2 1150°F [620°C]
Grades 2 Class 1 and 3 Class 1 1200°F [650°C]
Grades 4N Classes 1 and 2, and 5 1100°F [595°C]
Classes 1 and 2
Grade 4N Class 3 1125°F [605°C]
Grades 3V and 3VCb 1250°F [675°C]
Grade 22, Class 3 1200°F [650°C]
Grade 22, Classes 4, 5, 6, and 7 1100°F [593°C]
Specific cooling rates from the tempering temperature shall be applied if Supplementary Requirement S14 is specified.
4.3 For Grades 1, 1A, 2, 2A, 3, or 3A, a multiple stage austenitizing procedure may be used whereby the forging is first fully
austenitized and liquid quenched, followed by reheating within the intercritical temperature range to partially reaustenitize and
again liquid quenched. On completion of the austenitizing/quenching cycles, the forgings shall be tempered at a subcritical
temperature as described in 4.2.2.
5. Chemical Composition
5.1 HeatAnalysis—TheheatanalysisobtainedfromsamplinginaccordancewithSpecificationA788/A788Mshallcomplywith
Table 1 except that the additional features of Supplementary Requirements S7, S8, S9, and S11 shall also apply as individually
specified in the ordering information.
5.2 Product Analysis—The manufacturer shall use the product analysis provision of Specification A788/A788M to obtain a
product analysis from a forging representing each heat or multiple heat. The permissible variations provided in the table on
PermissibleVariations in ProductAnalysis for Killed Steel in SpecificationA788/A788M apply for manganese, nickel, chromium,
molybdenum, and vanadium only. Boron is not subject to product analysis. The purchaser may also make this determination in
accordance with Specification A788/A788M.
6. Mechanical Properties
6.1 Tension Test:
6.1.1 The steel shall conform to the requirements of Table 2.
6.1.2 The location and number of tension test specimens for each forging or multiple forging shall be as follows:
6.1.2.1 Multiple Forgings Separated into Identical Individual Forgings with Rough Machined Weights not Exceeding 1000 lb
[455 kg] Prior to Quenching and Tempering Treatment—At least one individual forging from each multiple forging in each
heat-treating lot shall be tested using the test specimen locations of 6.1.5 or 6.1.6 as specified on the purchase orders, except that
test specimens located at midlength may be closer to the ends of the production forging than the specified distance to the second
surfaces.All forgings shall be quenched and tempered in the same furnace charge.All forgings from the multiple shall be Brinell
hardnesstestedafterheattreatmentandforgingsnottestedformechanicalpropertiesshallhaveaBrinellHardnesswithin20points
of the Brinell Hardness of the forging that has been tested for mechanical properties.
6.1.2.2 Forgings or Multiple Forgings (Note 3) with Rough Machined Weights Less than 10000 lb [4540 kg] and Having a
Heat-Treated Length (Exclusive of Test Prolongation) of 80 in. [2032 mm] or Less—Atest prolongation (Note 4) shall be located
at one end. One tension test specimen shall be taken from the test prolongation.
6.1.2.3 ForgingsorMultipleForgingswithRoughMachinedWeightsLessthan10000lb[4540kg]andHavingaHeat-Treated
Length (Exclusive of Test Prolongations) Exceeding 80 in. [2032 mm]—A test prolongation shall be located at each end. One
tension test specimen shall be taken from each test prolongation. An orientation of 180° shall be established between the two
tension test specimens.
6.1.2.4 Forgings or Multiple Forgings with Rough Machined Weights Over 10000 lb [4540 kg] and Having a Heat-Treated
Length(ExclusiveofTestProlongation)of80in.[2032mm]orLess—Atest prolongation shall be located at one end.Two tension
test specimens shall be taken from the test prolongation and shall be oriented 180° apart.
6.1.2.5 Forgings or Multiple Forgings with Rough Machined Weights Over 10000 lb [4540 kg] and Having a Heat-Treated
Length (Exclusive of Test Prolongations) Exceeding 80 in. [2032 mm]—A test prolongation shall be located at each end. The
tension test specimens oriented 180° apart from each other shall be taken from each test prolongation. The two tension specimens
locatedinonetestprolongationshallbeoriented90°inrelationtothetwotensionspecimenslocatedintheothertestprolongation.
NOTE 3—Multiple forgings in 6.1.2.2 through 6.1.2.5 are those which will be separated after the quench and temper treatment.
NOTE 4—A test prolongation is defined as that integral test metal located at an end of the forging or forging multiples.
6.1.3 Samples for mechanical test specimen shall be removed from forgings after the quenching and tempering heat treatment.
The sample material shall be subjected to a simulated post weld heat treatment if Supplementary Requirement S1 is specified.
6.1.4 For upset disk forgings, the longitudinal axis of the test
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