ASTM A372/A372M-03(2008)

Standard Specification for Carbon and Alloy Steel Forgings for Thin-Walled Pressure Vessels

ABSTRACT
This specification deals with carbon and alloy steel forgings (including gas bottles) for use in thin-walled pressure vessels. Covered here are the following grades of steel forgings: Grade A; Grade B; Grade C; Grade D; Grade E, Classes 55, 65, and 70; Grade F, Classes 55, 65, and 70; Grade G, Classes 55, 65, and 70; Grade H, Classes 55, 65, and 70; Grade J, Classes 55, 65, and 70; Grade K; Grade L; Grade J, Class 110; and Grade M, Classes 85 and 100. Materials shall be manufactured by melting procedures, and optionally heat treated by normalization, normalization and tempering, or liquid-quenching and tempering. Heat and product analyses shall be performed wherein steel specimens shall conform to required chemical compositions of carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, and vanadium. Steel materials shall also undergo bending, flattening and hardness tests and shall conform to required values of tensile strength, yield strength, elongation, and hardness. Forgings shall be subjected to magnetic particle examination as well.
SCOPE
1.1 This specification covers relatively thin-walled forgings (including gas bottles) for pressure vessel use. Three types of carbon steel and six types of alloy steel are included. Provision is made for integrally forging the ends of vessel bodies made from seamless pipe or tubing.  
Note 1—When working to the chemical and tensile requirements of this specification, the influence of wall thickness and cooling rate will necessarily eliminate certain forging sizes in each class.
Note 2—Designations have been changed as follows:
  CurrentFormerly Grade AType I Grade BType II Grade CType III Grade DType IV Grade E Class 55Type V Grade 1 Class 55 Grade E Class 65Type V Grade 1 Class 65 Grade E Class 70Type V Grade 1 Class 70 Grade F Class 55Type V Grade 2 Class 55 Grade F Class 65Type V Grade 2 Class 65 Grade F Class 70Type V Grade 2 Class 70 Grade G Class 55Type V Grade 3 Class 55 Grade G Class 65Type V Grade 3 Class 65 Grade G Class 70Type V Grade 3 Class 70 Grade H Class 55Type V Grade 4 Class 55 Grade H Class 65Type V Grade 4 Class 65 Grade H Class 70Type V Grade 4 Class 70 Grade J Class 55Type V Grade 5 Class 55 Grade J Class 65Type V Grade 5 Class 65 Grade J Class 70Type V Grade 5 Class 70 Grade KType VI Grade LType VII Grade J Class 110Type VIII Grade M Class 85Type IX Class A Grade M Class 100Type IX Class B  
1.2 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.
1.3 Unless the order specifies the applicable “M” specification designation (SI units), the material shall be furnished to inch-pound units.

General Information

• Status: Historical
• Publication Date: 29-Feb-2008
• ICS: 77.140.85 - Iron and steel forgings
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.06 - Steel Forgings and Billets

Relations

• Replaces: ASTM A372/A372M-03 - Standard Specification for Carbon and Alloy Steel Forgings for Thin-Walled Pressure Vessels
• Effective Date: 01-Mar-2008
• Replaced By: ASTM A372/A372M-10 - Standard Specification for Carbon and Alloy Steel Forgings for Thin-Walled Pressure Vessels
• Effective Date: 01-Oct-2010
• Referred By: ASTM A788/A788M-23 - Standard Specification for Steel Forgings, General Requirements
• Effective Date: 01-Mar-2008

Standards Content (Sample)

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: A372/A372M – 03 (Reapproved 2008)
Standard Specification for
Carbon and Alloy Steel Forgings for Thin-Walled Pressure
Vessels
This standard is issued under the fixed designationA372/A372M; 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.
1. Scope 1.3 Unless the order specifies the applicable “M” specifica-
tion designation (SI units), the material shall be furnished to
1.1 This specification covers relatively thin-walled forg-
inch-pound units.
ings (including gas bottles) for pressure vessel use.Three types
of carbon steel and six types of alloy steel are included.
2. Referenced Documents
Provision is made for integrally forging the ends of vessel
2.1 ASTM Standards:
bodies made from seamless pipe or tubing.
A275/A275M Practice for Magnetic Particle Examination
NOTE 1—When working to the chemical and tensile requirements of
of Steel Forgings
this specification, the influence of wall thickness and cooling rate will
A370 Test Methods and Definitions for Mechanical Testing
necessarily eliminate certain forging sizes in each class.
of Steel Products
NOTE 2—Designations have been changed as follows:
A388/A388M Practice for Ultrasonic Examination of Steel
Current Formerly
Forgings
Grade A Type I
Grade B Type II
A530/A530M Specification for General Requirements for
Grade C Type III
Specialized Carbon and Alloy Steel Pipe
Grade D Type IV
A788/A788M Specification for Steel Forgings, General Re-
Grade E Class 55 Type V Grade 1 Class 55
Grade E Class 65 Type V Grade 1 Class 65
quirements
Grade E Class 70 Type V Grade 1 Class 70
E112 Test Methods for Determining Average Grain Size
Grade F Class 55 Type V Grade 2 Class 55
E165 PracticeforLiquidPenetrantExaminationforGeneral
Grade F Class 65 Type V Grade 2 Class 65
Grade F Class 70 Type V Grade 2 Class 70
Industry
Grade G Class 55 Type V Grade 3 Class 55
E290 Test Methods for Bend Testing of Material for Duc-
Grade G Class 65 Type V Grade 3 Class 65
tility
Grade G Class 70 Type V Grade 3 Class 70
Grade H Class 55 Type V Grade 4 Class 55
E433 Reference Photographs for Liquid Penetrant Inspec-
Grade H Class 65 Type V Grade 4 Class 65
tion
Grade H Class 70 Type V Grade 4 Class 70
Grade J Class 55 Type V Grade 5 Class 55
3. Ordering Information and General Requirements
Grade J Class 65 Type V Grade 5 Class 65
Grade J Class 70 Type V Grade 5 Class 70
3.1 In addition to the ordering information required by
Grade K Type VI
Specification A788/A788M, the purchaser shall include with
Grade L Type VII
Grade J Class 110 Type VIII
the inquiry and order a detailed drawing, sketch, or written
Grade M Class 85 Type IX Class A
descriptionoftheforgingandtheareasofsignificantloadingin
Grade M Class 100 Type IX Class B
the forging when required (see 6.4.2.2).
1.2 The values stated in either SI units or inch-pound units
3.2 Material supplied to this specification shall conform to
are to be regarded separately as standard. The values stated in
the requirements of Specification A788/A788M, which out-
each system may not be exact equivalents; therefore, each
lines additional ordering information, manufacturing require-
system shall be used independently of the other. Combining
ments, testing and retesting methods and procedures, marking,
values from the two systems may result in non-conformance
certification,productanalysisvariations,andadditionalsupple-
with the standard.
mentary requirements.
3.3 If the requirements of this specification are in conflict
with the requirements of Specification A788/A788M, the
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee requirements of this specification shall prevail.
A01.06 on Steel Forgings and Billets.
Current edition approved March 1, 2008. Published April 2008. Originally
published in 1953. Last previous edition approved in 2003 as A372/A372M – 03. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
DOI: 10.1520/A0372_A0372M-03R08. contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
For ASME Boiler and Pressure Vessel Code applications, see related Specifi- Standards volume information, refer to the standard’s Document Summary page on
cation SA-372/SA-372M in Section II of that code. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A372/A372M – 03 (2008)
TABLE 1 Chemical Requirements
4. Materials and Manufacture
Elements Composition, %
4.1 Melting Practice:
Grade A Grade B Grade C Grade D
4.1.1 The steel melting procedures of Specification A788/
Carbon 0.30 max 0.35 max 0.48 max 0.40–0.50
A788MshallapplyexceptthatforGradeMforgings,onlysteel
Manganese 1.00 max 1.35 max 1.65 max 1.40–1.80
that has been vacuum treated prior to or during the pouring of
Phosphorus, 0.025 0.025 0.025 0.025
the ingot, in order to remove objectionable gases, particularly
max
Sulfur, max 0.025 0.025 0.025 0.025
hydrogen, shall be used.
Silicon 0.15–0.35 0.15–0.35 0.15–0.35 0.15–0.35
4.2 Production Methods:
Nickel — — — —
4.2.1 Methods for the production of gas bottles and similar Chromium — — — —
Molybdenum — — — 0.17–0.27
vesselsshallincludethecuppingofslabsorplates,thepiercing
Grade E Grade F Grade G Grade H Grade J
of billets or plates, and the subsequent drawing of cups so
Classes Classes Classes Classes Classes 55,
produced. Such semifinished forgings or seamless steel pipe or
55, 65, 70 55, 65, 70 55, 65, 70 55, 65, 70 65, 70, 110
tubingshallbeclosedbyspinning,swedging,orpressing.Inall
Carbon 0.25–0.35 0.30–0.40 0.25–0.35 0.30–0.40 0.35–0.50
casesthereshallbesufficientdiscardtoensuresoundnessinthe
Manganese 0.40–0.90 0.70–1.00 0.70–1.00 0.75–1.05 0.75–1.05
completed forging.
Phosphorus, 0.025 0.025 0.025 0.025 0.025
max
4.3 Heat Treatment:
Sulfur, max 0.025 0.025 0.025 0.025 0.025
4.3.1 At the option of the manufacturer, Grades A, B, C, D
Silicon 0.15–0.35 0.15–0.35 0.15–0.35 0.15–0.35 0.15–0.35
Nickel — — — — —
and Classes 55, 65, 70 of Grades E, F, G, H, and J forgings
Chromium 0.80–1.15 0.80–1.15 0.40–0.65 0.40–0.65 0.80–1.15
shall be normalized, normalized and tempered, or liquid-
Molybdenum 0.15–0.25 0.15–0.25 0.15–0.25 0.15–0.25 0.15–0.25
quenched and tempered.
Grade K Grade L Grade M
4.3.2 Grades K, L, M, and Class 110 of Grade J forgings
Classes 85
shall be liquid-quenched and tempered. and 100
4.3.3 When normalized forgings are to be tempered, or Carbon 0.18 max 0.38–0.43 0.23 max
Manganese 0.10–0.40 0.60–0.80 0.20–0.40
when forgings have been quenched, they shall be reheated to a
Phosphorus, 0.025 max 0.025 0.020
subcritical temperature and held for at least ⁄2 h/in. [25 mm] of
max
maximum cross section. Sulfur, max 0.025 max 0.025 0.020
Silicon 0.15–0.35 0.15–0.35 0.30 max
4.3.3.1 Minimum tempering temperatures shall be as fol-
Nickel 2.0–3.3 1.65–2.00 2.8–3.9
lows:
Chromium 1.00–1.80 0.70–0.90 1.50–2.00
Molybdenum 0.20–0.60 0.20–0.30 0.40–0.60
Grades E, F, G, H, J in Classes 55, 65, 70 1100°F [595°C]
Vanadium 0.08 max
Grade K 1100°F [595°C]
Grade L 1000°F [540°C]
Grade J Class 110 1000°F [540°C]
Grade M 1100°F [595°C]
6. Mechanical Properties
4.3.3.2 If an attachment is welded onto a previously
6.1 Mechanical tests for acceptance shall be made after the
quenched and tempered pressure vessel, the post weld heat
final heat treatment of the forgings.
treatment temperature of a weldment shall not exceed the prior
6.2 Tension Test—When tested in accordance with Test
tempering temperature of the pressure vessel. Fabrication
Methods and Definitions A370, the material shall conform to
welding of pressure shell is not permitted.Attachment welding
prior to heat treatment is not permitted.
4.3.4 All quenched and tempered forgings shall be subject
TABLE 2 Mechanical Requirements
to magnetic particle examination in accordance with Section 7.
Yield Elongation
4.3.5 Heat treatment is to be performed after all forming
Strength in2in.
Tensile Strength, (0.2 % Offset), [50 mm], Hardness,
operations.
A
Type ksi [MPa] ksi [MPa], min min, % HB, min
Grade A 60–85 [415–585] 35 [240] 20 121
5. Chemical Composition
Grade B 75–100 [515–690] 45 [310] 18 156
Grade C 90–115 [620–795] 55 [380] 15 187
5.1 Heat Analysis—The heat analysis obtained from sam-
Grade D 105–130 [725–895] 65 [450] 15 217
pling in accordance with Specification A788/A788M shall
Grades E, F, G, 85–110 [545–760] 55 [380] 20 179
comply with Table 1.
H, J (Class 55)
Grades E, F, G, 105–130 [725–895] 65 [450] 19 217
5.2 Product Analysis—The purchaser may use the product
H, J (Class 65)
analysis provision of Specification A788/A788M to obtain a
Grades E, F, G, 120–145 [825–1000] 70 [485] 18 248
product analysis from a forging representing each heat or H, J (Class 70)
Grade J 135–160 [930–1100] 110 [760] 15 277
multiple heat.
(Class 110)
5.3 Starting material produced to a specification that spe-
Grade K 100–125 [690–860] 80 [550] 20 207
Grade L 155–180 [1070–1240] 135 [930] 12 311
cifically requires the addition of any element beyond those
Grade M 105–130 [725–895] 85 [585] 18 217
listed in Table 1 for the applicable grade of material is not
(Class 85)
permitted. This does not preclude use of deoxidation or
Grade M 120–145 [825–1000] 100 [690] 16 248
(Class 100)
inclusion control additions. Supplementary Requirements S1
A
and S2 of Specification A788/A788M shall apply. When required by 6.6.
A372/A372M – 03 (2008)
TABLE 4 Maximum Pin Diameters and Minimum Angle for Bend
the requirements of Table 2. The yield strength shall be
Test
determined by the 0.2 % offset method.
Type Pin Diameter Angle, deg
6.3 BendingProperties
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM 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.
An American National Standard Designation: A 372/A 372M – 03 (Reapproved 2008)
Designation:A 372/A 372M–02
Standard Specification for
Carbon and Alloy Steel Forgings for Thin-Walled Pressure
Vessels
This standard is issued under the fixed designationA372/A372M; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope *
1.1 This specification covers relatively thin-walled forgings (including gas bottles) for pressure vessel use. Three types of
carbon steel and six types of alloy steel are included. Provision is made for integrally forging the ends of vessel bodies made from
seamless pipe or tubing.
NOTE 1—When working to the chemical and tensile requirements of this specification, the influence of wall thickness and cooling rate will necessarily
eliminate certain forging sizes in each class.
NOTE 2—Designations have been changed as follows:
Current Formerly
Grade A Type I
Grade B Type II
Grade C Type III
Grade D Type IV
Grade E Class 55 Type V Grade 1 Class 55
Grade E Class 65 Type V Grade 1 Class 65
Grade E Class 70 Type V Grade 1 Class 70
Grade F Class 55 Type V Grade 2 Class 55
Grade F Class 65 Type V Grade 2 Class 65
Grade F Class 70 Type V Grade 2 Class 70
Grade G Class 55 Type V Grade 3 Class 55
Grade G Class 65 Type V Grade 3 Class 65
Grade G Class 70 Type V Grade 3 Class 70
Grade H Class 55 Type V Grade 4 Class 55
Grade H Class 65 Type V Grade 4 Class 65
Grade H Class 70 Type V Grade 4 Class 70
Grade J Class 55 Type V Grade 5 Class 55
Grade J Class 65 Type V Grade 5 Class 65
Grade J Class 70 Type V Grade 5 Class 70
Grade K Type VI
Grade L Type VII
Grade J Class 110 Type VIII
Grade M Class 85 Type IX Class A
Grade M Class 100 Type IX Class B
1.2The values stated in either inch-pound or SI [metric] units are to be regarded separately as the standard. Within the text and
the tables, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system
must be used independently of the other. Combining values from the two systems may result in nonconformance with the
specification.
1.2 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.
1.3 Unless the order specifies the applicable “M” specification designation (SI units), the material shall be furnished to
inch-pound units.
This specification is under the jurisdiction ofASTM CommitteeA01 on Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of SubcommitteeA01.06
on Steel Forgings and Billets.
Current edition approved September 10, 2002. Published June 2003. Originally published in 1953. Last previous edition approved in 1999 as A372/A372M–99.
Current edition approved March 1, 2008. Published April 2008. Originally published in 1953. Last previous edition approved in 2003 as A 372/A 372M – 03.
For ASME Boiler and Pressure Vessel Code applications, see related Specification SA-372/SA-372M in Section II of that code.
*ASummary of Changes section appears at the end of this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A 372/A 372M – 03 (2008)
2. Referenced Documents
2.1 ASTM Standards:
A 275/A 275M Test Method Practice for Magnetic Particle Examination of Steel Forgings
A 370 Test Methods and Definitions for Mechanical Testing of Steel Products
A 388/A 388M Practice for Ultrasonic Examination of Heavy Steel Forgings
A 530/A 530M Specification for General Requirements for Specialized Carbon and Alloy Steel Pipe
A 788/A 788M Specification for Steel Forgings, General Requirements
E 112 Test Methods for Determining the Average Grain Size
E 165Practice for Liquid Penetrant Examination Test Method for Liquid Penetrant Examination
E 290Test Method for Semi-Guided Bend Test for Ductility of Metallic Materials Test Methods for Bend Testing of Material
for Ductility
E 433 Reference Photographs for Liquid Penetrant Inspection
3. Ordering Information and General Requirements
3.1 InadditiontotheorderinginformationrequiredbySpecificationA 788/A 788M,thepurchasershallincludewiththeinquiry
and order a detailed drawing, sketch, or written description of the forging and the areas of significant loading in the forging when
required (see 6.4.2.2).
3.2 Material supplied to this specification shall conform to the requirements of Specification A 788/A 788M, which outlines
additional ordering information, manufacturing requirements, testing and retesting methods and procedures, marking, certification,
product analysis variations, and additional supplementary requirements.
3.3 If the requirements of this specification are in conflict with the requirements of Specification A 788/A 788M, the
requirements of this specification shall prevail.
4. Materials and Manufacture
4.1 Melting Practice:
4.1.1 The steel melting procedures of SpecificationA 788/A 788M shall apply except that for Grade M forgings, only steel that
has been vacuum treated prior to or during the pouring of the ingot, in order to remove objectionable gases, particularly hydrogen,
shall be used.
4.2 Production Methods:
4.2.1 Methods for the production of gas bottles and similar vessels mayshall include the cupping of slabs or plates, the piercing
of billets or plates, and the subsequent drawing of cups so produced. Such semifinished forgings or seamless steel pipe or tubing
mayshall be closed by spinning, swedging, or pressing. In all cases there shall be sufficient discard to ensure soundness in the
completed forging.
4.3 Heat Treatment:
4.3.1 At the option of the manufacturer, Grades A, B, C, D and Classes 55, 65, 70 of Grades E, F, G, H, and J forgings shall
be normalized, normalized and tempered, or liquid-quenched and tempered.
4.3.2 Grades K, L, M, and Class 110 of Grade J forgings shall be liquid-quenched and tempered.
4.3.3 When normalized forgings are to be tempered, or when forgings have been quenched, they shall be reheated to a
subcritical temperature and held for at least ⁄2 h/in. [25 mm] of maximum cross section.
4.3.3.1 Minimum tempering temperatures shall be as follows:
Grades E, F, G, H, J in Classes 55, 65, 70 1100°F [595°C]
Grade K 1100°F [595°C]
Grade L 1000°F [540°C]
Grade J Class 110 1000°F [540°C]
Grade M 1100°F [595°C]
4.3.3.2 If an attachment is welded onto a previously quenched and tempered pressure vessel, the post weld heat treatment
temperature of a weldment shall not exceed the prior tempering temperature of the pressure vessel. Fabrication welding of pressure
shell is not permitted. Attachment welding prior to heat treatment is not permitted.
4.3.4 All quenched and tempered forgings shall be subject to magnetic particle examination in accordance with Section 7.
4.3.5 Heat treatment is to be performed after all forming operations.
5. Chemical Composition
5.1 Heat Analysis—The heat analysis obtained from sampling in accordance with Specification A 788/A 788M shall comply
with Table 1.
5.2 Product Analysis—The purchaser may use the product analysis provision of Specification A 788/A 788M to obtain a
product analysis from a forging representing each heat or multiple heat.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at [e-mail]. For Annual Book ofASTM Standards
, Vol 01.05.volume information, refer to the standard’s Document Summary page on the ASTM website.
A 372/A 372M – 03 (2008)
TABLE 1 Chemical Requirements
Elements Composition, %
Grade A Grade B Grade C Grade D
Carbon 0.30 max 0.35 max 0.48 max 0.40–0.50
Manganese 1.00 max 1.35 max 1.65 max 1.40–1.80
Phosphorus, 0.025 0.025 0.025 0.025
max
Sulfur, max 0.025 0.025 0.025 0.025
Silicon 0.15–0.35 0.15–0.35 0.15–0.35 0.15–0.35
Nickel — — — —
Chromium — — — —
Molybdenum — — — 0.17–0.27
Grade E Grade F Grade G Grade H Grade J
Classes Classes Classes Classes Classes 55,
55, 65, 70 55, 65, 70 55, 65, 70 55, 65, 70 65, 70, 110
Carbon 0.25–0.35 0.30–0.40 0.25–0.35 0.30–0.40 0.35–0.50
Manganese 0.40–0.90 0.70–1.00 0.70–1.00 0.75–1.05 0.75–1.05
Phosphorus, 0.025 0.025 0.025 0.025 0.025
max
Sulfur, max 0.025 0.025 0.025 0.025 0.025
Silicon 0.15–0.35 0.15–0.35 0.15–0.35 0.15–0.35 0.15–0.35
Nickel — — — — —
Chromium 0.80–1.15 0.80–1.15 0.40–0.65 0.40–0.65 0.80–1.15
Molybdenum 0.15–0.25 0.15–0.25 0.15–0.25 0.15–0.25 0.15–0.25
Grade K Grade L Grade M
Classes 85
and 100
Carbon 0.18 max 0.38–0.43 0.23 max
Manganese 0.10–0.40 0.60–0.80 0.20–0.40
Phosphorus, 0.025 max 0.025 0.020
max
Sulfur, max 0.025 max 0.025 0.020
Silicon 0.15–0.35 0.15–0.35 0.30 max
Nickel 2.0–3.3 1.65–2.00 2.8–3.9
Chromium 1.00–1.80 0.70–0.90 1.50–2.00
Molybdenum 0.20–0.60 0.20–0.30 0.40–0.60
Vanadium 0.08 max
5.3 Starting material produced to a specification that specifically requires the addition of any element beyond those listed in
Table 1 for the applicable grade of material is not permitted. This does not preclude use of deoxidation or inclusion control
additions. Supplementary Requirements S1 and S2 of Specification A 788/A 788M shall apply.
6. Mechanical Properties
6.1 Mechanical tests for acceptance shall be made after the final heat treatment of the forgings.
6.2 Tension Test—When tested in accordance with Test Methods and Definitions A 370, the material shall conform to the
requirements of Table 2. The yield strength shall be determined by the 0.2 % offset method.
6.3 BendingProperties—Dependingupontheoutsidediameter,D,andthewallthickness,T,ofholloworboredforgings,abend
test or flattening test will be required.
6.3.1 For bored or hollow forgings with outside diameters of 14 in. [355 mm] or less and with a D/T ratio of more than 10.0,
a flattening test is required. This shall be carried out in accordance with Specification A 530/A 530M/A530M and Table 3. No
breaks or cracks in the test ring are acceptable until the distance between the plates is less than that shown in Table 3.
6.3.2 For bored or hollow forgings with outside diameters over 14 in. [355 mm], or where the D/T ratio is 10.0 or less at the
manufacturer’s o
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM 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:A 372/A 372M–03 Designation: A372/A372M – 03 (Reapproved 2008)
Standard Specification for
Carbon and Alloy Steel Forgings for Thin-Walled Pressure
Vessels
This standard is issued under the fixed designationA372/A372M; 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.
1. Scope *
1.1 This specification covers relatively thin-walled forgings (including gas bottles) for pressure vessel use. Three types of
carbon steel and six types of alloy steel are included. Provision is made for integrally forging the ends of vessel bodies made from
seamless pipe or tubing.
NOTE 1—When working to the chemical and tensile requirements of this specification, the influence of wall thickness and cooling rate will necessarily
eliminate certain forging sizes in each class.
NOTE 2—Designations have been changed as follows:
Current Formerly
Grade A Type I
Grade B Type II
Grade C Type III
Grade D Type IV
Grade E Class 55 Type V Grade 1 Class 55
Grade E Class 65 Type V Grade 1 Class 65
Grade E Class 70 Type V Grade 1 Class 70
Grade F Class 55 Type V Grade 2 Class 55
Grade F Class 65 Type V Grade 2 Class 65
Grade F Class 70 Type V Grade 2 Class 70
Grade G Class 55 Type V Grade 3 Class 55
Grade G Class 65 Type V Grade 3 Class 65
Grade G Class 70 Type V Grade 3 Class 70
Grade H Class 55 Type V Grade 4 Class 55
Grade H Class 65 Type V Grade 4 Class 65
Grade H Class 70 Type V Grade 4 Class 70
Grade J Class 55 Type V Grade 5 Class 55
Grade J Class 65 Type V Grade 5 Class 65
Grade J Class 70 Type V Grade 5 Class 70
Grade K Type VI
Grade L Type VII
Grade J Class 110 Type VIII
Grade M Class 85 Type IX Class A
Grade M Class 100 Type IX Class B
1.2The values stated in either inch-pound or SI [metric] units are to be regarded separately as the standard. Within the text and
the tables, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system
must be used independently of the other. Combining values from the two systems may result in nonconformance with the
specification.
1.2 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.
1.3 Unless the order specifies the applicable “M” specification designation (SI units), the material shall be furnished to
inch-pound units.
This specification is under the jurisdiction ofASTM CommitteeA01 on Steel, Stainless Steel and RelatedAlloys and is the direct responsibility of SubcommitteeA01.06
on Steel Forgings and Billets.
Current edition approved June 10, 2003. Published August 2003. Originally published in 1953. Last previous edition approved in 2002 as A 372/A 372M–02.
Current edition approved March 1, 2008. Published April 2008. Originally published in 1953. Last previous edition approved in 2003 as A372/A372M – 03. DOI:
10.1520/A0372_A0372M-03R08.
For ASME Boiler and Pressure Vessel Code applications, see related Specification SA-372/SA-372M in Section II of that code.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A372/A372M – 03 (2008)
2. Referenced Documents
2.1 ASTM Standards:
A275/A275M Test Method 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 Heavy Steel Forgings
A530/A530M Specification for General Requirements for Specialized Carbon and Alloy Steel Pipe
A788788/A788M Specification for Steel Forgings, General Requirements
E112 Test Methods for Determining the Average Grain Size
E165 Practice for Liquid Penetrant Examination Practice for Liquid Penetrant Examination for General Industry
E290 Test Method for Semi-Guided Bend Test for Ductility of Metallic Materials Test Methods for Bend Testing of Material
for Ductility
E433 Reference Photographs for Liquid Penetrant Inspection
3. Ordering Information and General Requirements
3.1 In addition to the ordering information required by SpecificationA788A788A788/A788M, the purchaser shall include with
the inquiry and order a detailed drawing, sketch, or written description of the forging and the areas of significant loading in the
forging when required (see 6.4.2.2).
3.2 Material supplied to this specification shall conform to the requirements of SpecificationA788A788A788/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 If the requirements of this specification are in conflict with the requirements of SpecificationA788A788A788/A788M, the
requirements of this specification shall prevail.
4. Materials and Manufacture
4.1 Melting Practice:
4.1.1 ThesteelmeltingproceduresofSpecificationA788A788A788/A788MshallapplyexceptthatforGradeMforgings,only
steel that has been vacuum treated prior to or during the pouring of the ingot, in order to remove objectionable gases, particularly
hydrogen, shall be used.
4.2 Production Methods:
4.2.1 Methods for the production of gas bottles and similar vessels shall include the cupping of slabs or plates, the piercing of
billets or plates, and the subsequent drawing of cups so produced. Such semifinished forgings or seamless steel pipe or tubing shall
be closed by spinning, swedging, or pressing. In all cases there shall be sufficient discard to ensure soundness in the completed
forging.
4.3 Heat Treatment:
4.3.1 At the option of the manufacturer, Grades A, B, C, D and Classes 55, 65, 70 of Grades E, F, G, H, and J forgings shall
be normalized, normalized and tempered, or liquid-quenched and tempered.
4.3.2 Grades K, L, M, and Class 110 of Grade J forgings shall be liquid-quenched and tempered.
4.3.3 When normalized forgings are to be tempered, or when forgings have been quenched, they shall be reheated to a
subcritical temperature and held for at least ⁄2 h/in. [25 mm] of maximum cross section.
4.3.3.1 Minimum tempering temperatures shall be as follows:
Grades E, F, G, H, J in Classes 55, 65, 70 1100°F [595°C]
Grade K 1100°F [595°C]
Grade L 1000°F [540°C]
Grade J Class 110 1000°F [540°C]
Grade M 1100°F [595°C]
4.3.3.2 If an attachment is welded onto a previously quenched and tempered pressure vessel, the post weld heat treatment
temperature of a weldment shall not exceed the prior tempering temperature of the pressure vessel. Fabrication welding of pressure
shell is not permitted. Attachment welding prior to heat treatment is not permitted.
4.3.4 All quenched and tempered forgings shall be subject to magnetic particle examination in accordance with Section 7.
4.3.5 Heat treatment is to be performed after all forming operations.
5. Chemical Composition
5.1 HeatAnalysis—The heat analysis obtained from sampling in accordance with SpecificationA788A788A788/A788M shall
comply with Table 1.
5.2 Product Analysis—The purchaser may use the product analysis provision of Specification A 788A 788A788/A788M to
obtain a product analysis from a forging representing each heat or multiple heat.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at [e-mail]. For Annual Book ofASTM Standards
, Vol 01.05.volume information, refer to the standard’s Document Summary page on the ASTM website.
A372/A372M – 03 (2008)
TABLE 1 Chemical Requirements
Elements Composition, %
Grade A Grade B Grade C Grade D
Carbon 0.30 max 0.35 max 0.48 max 0.40–0.50
Manganese 1.00 max 1.35 max 1.65 max 1.40–1.80
Phosphorus, 0.025 0.025 0.025 0.025
max
Sulfur, max 0.025 0.025 0.025 0.025
Silicon 0.15–0.35 0.15–0.35 0.15–0.35 0.15–0.35
Nickel — — — —
Chromium — — — —
Molybdenum — — — 0.17–0.27
Grade E Grade F Grade G Grade H Grade J
Classes Classes Classes Classes Classes 55,
55, 65, 70 55, 65, 70 55, 65, 70 55, 65, 70 65, 70, 110
Carbon 0.25–0.35 0.30–0.40 0.25–0.35 0.30–0.40 0.35–0.50
Manganese 0.40–0.90 0.70–1.00 0.70–1.00 0.75–1.05 0.75–1.05
Phosphorus, 0.025 0.025 0.025 0.025 0.025
max
Sulfur, max 0.025 0.025 0.025 0.025 0.025
Silicon 0.15–0.35 0.15–0.35 0.15–0.35 0.15–0.35 0.15–0.35
Nickel — — — — —
Chromium 0.80–1.15 0.80–1.15 0.40–0.65 0.40–0.65 0.80–1.15
Molybdenum 0.15–0.25 0.15–0.25 0.15–0.25 0.15–0.25 0.15–0.25
Grade K Grade L Grade M
Classes 85
and 100
Carbon 0.18 max 0.38–0.43 0.23 max
Manganese 0.10–0.40 0.60–0.80 0.20–0.40
Phosphorus, 0.025 max 0.025 0.020
max
Sulfur, max 0.025 max 0.025 0.020
Silicon 0.15–0.35 0.15–0.35 0.30 max
Nickel 2.0–3.3 1.65–2.00 2.8–3.9
Chromium 1.00–1.80 0.70–0.90 1.50–2.00
Molybdenum 0.20–0.60 0.20–0.30 0.40–0.60
Vanadium 0.08 max
5.3 Starting material produced to a specification that specifically requires the addition of any element beyond those listed in
Table 1 for the applicable grade of material is not permitted. This does not preclude use of deoxidation or inclusion control
additions. Supplementary Requirements S1 and S2 of Specification A 788A 788A788/A788M shall apply.
6. Mechanical Properties
6.1 Mechanical tests for acceptance shall be made after the final heat treatment of the forgings.
6.2 Tension Test—When tested in accordance with Test Methods and DefinitionsA370A370, the material shall conform to the
requirements of Table 2. The yield strength shall be determined by the 0.2 % offset method.
6.3 BendingProperties—Dependingupontheoutsidediameter,D,andthewallthickness,T,ofholloworboredforgings,abend
test or flattening test will be required.
6.3.1 For bored or hollow forgings with outside diameters of 14 in. [355 mm] or less and with a D/T ratio of more than 10.0,
a flattening test is required. This shall be carried out in accordance with Specification A 530A530/A530M/A 530M and Table 3.
No breaks or cracks in the test ring are acceptable until the distance between the plates is less than that shown in Table 3.
6.3.2 For bored or hollow forgings with outside diameters over 14 in. [355 mm], or where the D/T ratio is 10.0 or less at the
manufacturer’s option, the flattening test specified in 6.3.1, or a transverse bend test in accordance with Arran
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