Designation: A 541/A 541M – 95 (Reapproved 1999) An American National Standard

Standard Specification for

Quenched and Tempered Carbon and Alloy Steel Forgings
for Pressure Vessel Components1
This standard is issued under the fixed designation A 541/A 541M; 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 2. Referenced Documents

1.1 This specification2 covers requirements for quenched 2.1 ASTM Standards:
and tempered carbon and alloy steel forgings for pressure A 275/A 275M Test Method for Magnetic Particle Exami-
vessel components. nation of Steel Forgings3
1.2 All grades are considered weldable under proper condi- A 370 Test Methods and Definitions for Mechanical Testing
tions. Welding technique is of fundamental importance, and it of Steel Products4
is presupposed that welding procedure and inspection will be in A 388/A 388M Practice for Ultrasonic Examination of
accordance with approved methods for the grade of material Heavy Steel Forgings3
used. A 788 Specification for Steel Forgings, General Require-
NOTE 1—Grades 1 and 1A have different chemistries but the same
ments3
mechanical requirements. E 208 Test Method for Conducting Drop-Weight Test to
NOTE 2—Designations have been changed as follows: Determine Nil-Ductility Transition Temperature of Ferritic
Current Formerly Steels5
Grade 1 Class 1 3. Ordering Information and General Requirements
Grade 1A Class 1A
Grade 1C Class 4 3.1 In addition to the ordering information required by
Grade 2 Class 1 Class 2 Specification A 788, the purchaser shall include with the
Grade 2 Class 2 Class 2A inquiry and order a detailed drawing that locates areas of
Grade 3 Class 1 Class 3
Grade 3 Class 2 Class 3A significant loading in the forging (when required); the method
Grade 4N Class 1 Class 7 of selecting test locations (see 6.2); purchase option (if any) in
Grade 4N Class 2 Class 7A accordance with 9.1, and any supplementary requirements
Grade 4N Class 3 Class 7B
Grade 5 Class 1 Class 8 desired.
Grade 5 Class 2 Class 8A 3.2 Material supplied to this specification shall conform to
Grade 11 Class 4 Class 11C the requirements of Specification A 788, which outlines addi-
Grade 22 Class 3 Class 22B
Grade 22 Class 4 Class 22C tional ordering information, manufacturing requirements, test-
Grade 22 Class 5 Class 22D ing and retesting methods and procedures, marking, certifica-
Grade 22V Class 22V
tion, product analysis variations, and additional supplementary
Grade 3V Class 3V
requirements.
1.3 The values stated in either inch-pound units or SI 3.3 If the requirements of this specification are in conflict
(metric) units are to be regarded separately as the standard. with the requirements of Specification A 788, the requirements
Within the text and tables, the SI units are shown in brackets. of this specification shall prevail.
The values stated in each system are not exact equivalents;
therefore, each system must be used independently of the other. 4. Chemical Composition
Combining values from the two systems may result in noncon- 4.1 Heat Analysis—The heat analysis obtained from sam-
formance with the specification. pling in accordance with Specification A 788 shall comply with
1.4 Unless the order specifies the applicable “M” specifica- Table 1 except that the additional features of Supplementary
tion designation, the material shall be furnished to the inch- Requirements S8, S9, S10, S12, and S15 shall also apply as
pound units. individually specified in the ordering information.
4.2 Product Analysis—The manufacturer shall use the prod-
1
This specification is under the jurisdiction of ASTM Committee A-1 on Steel, uct analysis provision of Specification A 788 to obtain a
Stainless Steel, and Related Alloys, and is the direct responsibility of Subcommittee
A01.06 on Steel Forgings and Billets.
Current edition approved Jan. 15, 1995. Published March 1995. Originally
3
published as A 541 – 65. Last previous edition A 541/A 541M – 94. Annual Book of ASTM Standards, Vol 01.05.
2 4
For ASME Boiler and Pressure Vessel Code applications see related Specifi- Annual Book of ASTM Standards, Vol 01.03.
5
cation SA-541/SA-541M in Section II of that Code. Annual Book of ASTM Standards, Vol 03.01.

Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.

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 A 541/A 541M
TABLE 1 Chemical Requirements Composition, %
Grade 1 Grade 1A Grade 2 Grade 3 Grade 1C Grade 11 Grade 22 Grade 4N Grade 5 Grade 3V Grade 22 Grade 22V Grade
Class 4 Classes 4 Class 3 3VCb
and 5
Carbon 0.35 max 0.30 max 0.27 max 0.25 max 0.18 max 0.10–0.20 0.05–0.15 0.23 max 0.23 max 0.10–0.15 0.11–0.15 0.11–0.15 0.10-0.15
Manganese 0.40–0.90 0.70–1.35 0.50–0.90 1.20–1.50 1.30 max 0.30–0.80 0.30–0.60 0.20–0.40 0.20–0.40 0.30–0.60 0.30–0.60 0.30–0.60 0.30-0.60
Phosphorus 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.020 max 0.015 max 0.015 max 0.020 max
Sulfur 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.025 max 0.020 max 0.015 max 0.010 max 0.010 max
SiliconA 0.15–0.35 0.15–0.40 0.15–0.35 0.15–0.35 0.15–0.35 0.50–1.00 0.50 max 0.30 max 0.30 max 0.10 max 0.50 max 0.10 max 0.10 max
Nickel 0.40 max 0.40 max 0.50–1.00 0.40–1.00 0.25 max 0.50 max 0.50 max 2.8–3.9 2.8–3.9 ... 0.25 max 0.25 max 0.25 max
Chromium 0.25 max 0.25 max 0.25–0.45 0.25 max 0.15 max 1.00–1.50 2.00–2.50 1.25–2.00 1.25–2.00 2.8–3.3 2.00–2.50 2.00–2.50 2.7-3.3
Molybdenum 0.10 max 0.10 max 0.55–0.70 0.45–0.60 0.05 max 0.45–0.65 0.90–1.10 0.40–0.60 0.40–0.60 0.90–1.10 0.90–1.10 0.90–1.10 0.90-1.10
Vanadium 0.05 max 0.05 max 0.05 max 0.05 max 0.02–0.12 0.05 max 0.05 max 0.03 max 0.08 max 0.20–0.30 0.02 max 0.25–0.35 0.20-0.30
Titanium ... ... ... ... ... ... ... ... ... 0.015–0.035 ... 0.030 max 0.015 max
Boron ... ... ... ... ... ... ... ... ... 0.001–0.003 ... 0.0020 max ...
Copper ... ... ... ... ... ... ... ... ... ... ... 0.20 max 0.25 max
Columbium ... ... ... ... ... ... ... ... ... ... ... 0.07 max 0.015-0.070
Calcium ... ... ... ... ... ... ... ... ... ... ... 0.015 maxB 0.0005-
0.0150
A
When vacuum carbon-deoxidation is required for the classes included in Supplementary Requirements S10, the silicon content shall be 0.10 % max.
B
For Grade 22V, rare earth metals (REM) may be added in place of calcium, subject to agreement between the producer and the purchaser. In that case the total amount
of REM shall be determined and reported.

product analysis from a forging representing each heat or 5.2 For Classes 1, 1A, 2, 2A, 3, or 3A, a multiple stage
multiple heat. The permissible variations of Table 1 of Speci- austenitizing procedure may be used whereby the forging is
fication A 788 do not apply to carbon, phosphorus, silicon and first fully austenitized and liquid quenched, followed by
sulphur for all classes, vanadium for Grade 1C and columbium reheating within the intercritical temperature range to partially
and calcium for Grades 22V and 3VCb. Boron is not subject to reaustenitize, and again liquid quenched. On completion of the
product analysis. The purchaser may also make this determi- austenitizing/quenching cycles, the forgings shall be tempered
nation in accordance with Specification A 788. at a subcritical temperature as described in 5.1.

5. Heat Treatment for Mechanical Properties 6. Mechanical Properties

5.1 After complete austenitization, the forgings shall be 6.1 General Requirements—The forgings shall conform to
quenched in a suitable liquid medium by spraying or immer- the requirements of Table 2. The forgings shall also conform to
sion. For Grade 22V forgings, the minimum austenitizing the requirements of Table 3 unless either Supplementary
temperature shall be 1650°F [900°C]. Quenching shall be Requirement S6 or S13 is specified, in which case the
followed by tempering at a subcritical temperature and holding requirements of those sections shall apply. The largest obtain-
at this temperature for a minimum time of 1⁄2 h/in. [25 mm] of able tension test specimen as specified in Fig. 4 of Test
maximum section thickness. Minimum tempering temperatures Methods and Definitions A 370 shall be used. Impact speci-
shall be: mens shall be Charpy V-notch, as shown in Fig. 10 of Test
Grade °F [°C] Methods and Definitions A 370. The usage of subsize impact
specimens due to material limitations must have prior pur-
1, 1A, 2 Class 2, 3 Class 2 1150 [620]
2, 3 Class 1, 22 Class 3 1200 [650] chaser approval.
1C, 11 Class 4, 22 Class 4, 4N Class 1, 4N 1100 [595] 6.2 Sampling—The longitudinal axis and mid-length of
Class 2, 5 Class 1, 5 Class 2 tension and impact test specimens shall be positioned in
22 Class 15 1050 [565]
4N Class 3 1125 [610] accordance with one of the following methods as specified by
3V, 3VCb 1250 [675] the purchaser:
22V 1250 [675] 6.2.1 Method 1—This method shall always be used when

TABLE 2 Tensile Requirements

Grades 2 Grade 2 Grade 4N Grades 4N
Class 1, Class 2 and Class 1 and Class 2 and
Grade 1 Grade 22 Grade 22 Grade 4N Grades 3V Grade 22 Grade
3 Class 1, Grade 3 Grade 5 5 Class 2
and 1A Class 4 Class 5 Class 3 and 22V Class 3 3VCb
1C and Class 2 Class 1
11 Class 4
Tensile strength, ksi 70–95 80–105 90–115 105–130 115–140 105–130 115–140 90–115 85–110 85–110 85–110
[MPa] [480–660] [550–720] [620–790] [720–900] [790–1000] [720–900] [790–1000] [620–790] [585–760] [585–760] [585-760]
Yield strength (0.2 % 36 [250] 50 [340] 65 [450] 85 [590] 100 [690] 85 [590] 100 [690] 70 [480] 60 [415] 55 [380] 60 [415]
offset), min, ksi
[MPa]
Elongation in 2 in. or 20 18 16 16 15 18 16 20 18 18 18
50 mm, min, %
Reduction of area, 38 38 35 45 40 48 45 48 45 45 45
min, %

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 A 541/A 541M
TABLE 3 Charpy V-Notch Impact Requirements at 40°F (4°C) (Except for 2A)A,B
Grades 1, Grade 2 Grade 2 Grade 22 Grades 22 Grades 3V and 3VCb,
1A, and Class 2 Class 1, Class 5 CL 4 4N Grade 22,
11 Class 4 and 3 3 Class 1 Classes 1, 2, 3 Class 3
Class 2 and 1C 5 Classes 1, 2 and Grade 22V
Minimum average value of set of three specimens, 15 [20] 35 [47]D 30 [41] 25 [34] 35 [47] 40 [55]E
ft·lbf (J)C
D
Minimum value of one specimen, ft·lbf (J) 10 [14] 30 [41] 25 [34] 20 [27] 30 [41] 35 [50]E
A
These Charpy values are for tests made on standard 10–mm square specimens. If sub-size impact specimens are used, the required minimum ft·lbf values shall be
determined by multiplying the ft·lbf values in Table 3 by 5⁄6 for 7.5 by 10-mm specimens, and by 2⁄3 for 5 by 10–mm specimens.
B
These values apply for tests at lower temperatures if Supplementary Requirement S6 is specified in the order.
C
Not more than one specimen from a set may be below this value.
D
Tested at 70°F [21°C].
E
Tested at 0°F [−18°C].

the maximum quenched thickness does not exceed 2 in. [50 magnetic particle test to ensure freedom from cracks unless the
mm]. Specimens shall be located in the production forging or welded areas are completely removed by subsequent machin-
test forging (as described in Method 4) at mid-thickness and at ing.
least 2 in. from other quenched surfaces. 6.4 Samples shall be removed from forgings after the
6.2.2 Method 2—t by 2t, where t is the distance from the quenching and tempering heat treatments. This sample material
area of significant loading (see 3.1) to the nearest quenched shall be subjected to a simulated post-weld heat treatment if
surface. However, the specimens shall not be nearer to one supplementary requirement S1 is specified.
quenched surface than 3⁄4 in. [20 mm] and to the second 6.5 Orientation—For upset disk forgings, the longitudinal
quenched surface than 11⁄2 in. [40 mm]. When this method of axis of all test specimens shall be oriented in the tangential
testing is employed, forgings are usually manufactured in direction. For all other forgings, the longitudinal axis of the
accordance with a purchaser-approved drawing showing pre- specimens shall be oriented in the direction of maximum
quenched dimensions and the location of mechanical test working of the forging unless Supplementary Requirements
specimens. S11 or S14 are imposed.
6.2.3 Method 3—1⁄4 T by T, where T is the maximum 6.6 Number of Tests:
thickness of the forging as heat treated. Where this method of 6.6.1 Forgings under 500 lb [230 kg] As Treated—For
testing is employed, the following limitations for as-treated duplicate forgings weighing less than 500 lb as treated, one
thickness shall apply, unless otherwise agreed upon: tension test and one impact test (three specimens) shall be
Grade in. [1 mm], max made to represent each heat in each heat-treatment charge.
When heat treatment is performed in continuous-type furnaces
1 and 1A 3 [75]
2 Class 2 and 3 Class 2 6 [150]
with suitable temperature control and equipped with recording
2 Class 1 and 3 Class 1 8 [205] pyrometers so that complete heat-treatment records are avail-
1C 4 [100] able, a heat-treatment charge shall be considered as any
11 Class 4 5 [125]
22 Class 4, 4N Class 2, 5 Class 2 6 [150]
continuous run not exceeding an 8-h duration.
22 Class 5 8 [205] 6.6.2 Forgings weighing 500 to 10 000 lb [230 to 4535 kg]
4N Class 1, 5 Class 1, 4N Class 3, 3V, 3VCb, 10 [255] As-Heat Treated—One tension and one impact test (3 speci-
22V, and 22 Class 3
mens) shall be made for each forging.
6.2.4 Method 4—Test specimens shall be taken from a 6.6.3 Each forging weighing over 10 000 lb [4535 kg] shall
representative separate test forging or bar made from the same require two tension tests and two impact tests, located at
heat of steel which shall receive substantially the same opposite ends if the length is 11⁄2 times the diameter or more,
reduction and type of hot working as the production forgings or 180 deg apart otherwise.
which it represents, except that a longitudinally forged bar may
be used to represent a rolled ring of similar cross section. It 7. Repair Welding
shall be of the same nominal thickness as the as-quenched 7.1 Repair welding of forgings may be permitted, but only
production forgings and shall be heat treated in the same at the option of the purchaser.
furnace charge and under the same conditions as the production 7.2 If repair welding is performed, welders and weld pro-
forgings. Test specimens shall be removed using the 1⁄4 T by T cedures shall be qualified in accordance with Section IX of the
procedure referenced in Method 3 with the same limitation on ASME Boiler and Pressure Vessel Code.
forging thickness as in 6.2.3. This method shall be limited to
forgings with a rough machined weight of not more than 1000 8. Workmanship and Quality Level Requirements
lb [455 kg]. 8.1 Dimensional and visual inspections shall be conducted
6.3 Metal Buffers—The required distances from quenched by the manufacturer. Forgings shall be free of cracks, thermal
surfaces may be obtained with metal buffers instead of integral ruptures, or other imperfections.
extensions. Buffer material may be carbon or low-alloy steel,
and shall be joined to the forging with a partial penetration 9. Certification and Reports
weld that seals the buffered surface. Specimens shall be located 9.1 In addition to items required to be reported by Specifi-
at least 1⁄2 in. [13 mm] from the buffered surface of the forging. cation A 788, the following items shall also be reported:
Buffers shall be removed and the welded areas subjected to 9.1.1 Product chemical analysis.

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 A 541/A 541M
9.1.2 The method used for locating test specimens. they shall be round-nosed or “interrupted-dot” die stamps
9.1.3 Sketches included in the report of non-destructive having a minimum radius of 1⁄32 in. [0.8 mm].
examinations.
9.1.4 Details of the heat treatment cycle, as listed in 11. Keywords
Specification A 788.
11.1 chromium-molybdenum steel; nickel-chromium-
10. Product Marking molybdenum alloy steel; pressure vessel service; quenched and
10.1 The purchaser may specify additional identification tempered steel; steel forgings—alloy; steel forgings—carbon
marking and the location of the marking. If stamps are used,

SUPPLEMENTARY REQUIREMENTS

One or more of the following supplementary requirements shall apply only when specified by the
purchaser in the inquiry or order. Details of these supplementary requirements shall be agreed upon
by the manufacturer and the purchaser.

S1. Simulated Post-Weld Heat Treatment of Mechanical may be employed to resolve questions of interpretation of
Test Samples ultrasonic indications. The manufacturer shall accept respon-
S1.1 All test coupons shall be subjected to single or multiple sibility for injurious conditions that will not be removed in final
heat treatments at subcritical temperatures prior to testing. machining.
Such treatments are intended to simulate post-weld or other S3. Magnetic Particle Examination
treatments to which the forgings will be subjected during S3.1 Each forging shall be inspected by magnetic particle
subsequent fabrication. The purchaser shall furnish the manu- methods described in Test Method A 275/A 275M. Acceptance
facturer with details of the desired heat treatment for the test and rejection standards shall be mutually agreed upon by the
coupons, including temperatures, times, and cooling rates. purchaser and manufacturer.
S2. Ultrasonic Inspection S4. Charpy V-Notch Impact Transition Curve
S2.1 Forgings shall be ultrasonically examined in accor- S4.1 Sufficient impact tests shall be made from the forging
dance with the procedures of Practice A 388/A 388M. test material to establish a temperature-absorbed energy curve.
S2.1.1 Longitudinal Wave Test: The test temperature range shall be wide enough to establish
S2.1.1.1 Unless otherwise specified, the back reflection the upper and lower shelf foot pound energies, with sufficient
method of tuning shall be used in accordance with the testing at intermediate temperatures to permit plotting a rea-
Procedure Section (the paragraph regarding Back–Reflection sonably smooth curve.
Technique) of Practice A 388/A 388M. S5. Additional Charpy Data
S2.1.1.2 In addition to the reportable conditions of the
Recording Section of Practice A 388/A 388M, indications S5.1 The percent shear fracture and mils or millimetres of
exceeding the resultant back reflection shall be recorded. lateral expansion, defined in Test Methods and Definitions
S2.1.1.3 The following conditions are subject to rejection: A 370, shall be reported for each Charpy specimen tested.
Complete loss of back reflection accompanied by an indica- S6. Charpy Impact Tests
tion of a discontinuity. For this purpose, a back reflection less S6.1 Charpy impact tests shall be made in accordance with
than 5 % of full screen height shall be considered complete loss the provisions of Section 6 of this specification except that the
of back reflection. test temperature shall be lower than that specified in Table 3.
An indication equal in amplitude to that of the back
reflection established in an indication-free portion of the S7. Drop-Weight Test
forging. S7.1 Drop-weight tests shall be conducted in accordance
S2.1.2 Angle Beam Test: with the requirements of Test Method E 208. The fracture plane
S2.1.2.1 Calibration notches, calibration reference, and of the specimens shall coincide with the location required for
method of scanning shall be in accordance with the Procedure other mechanical test specimens as specified by the purchaser
Section (the paragraph regarding Angle–Beam Examination) of in accordance with 6.2. However, since the drop-weight
Practice A 388/A 388M. specimen can be taken in any orientation, the fracture plane of
S2.1.2.2 A forging that contains a discontinuity which the specimen when tested to Method 2 (6.2.2) shall be a
results in an indication exceeding the amplitude of the refer- minimum distance of 7⁄16 in. [11 mm] from the nearest
ence line is subject to rejection. quenched surface, and 11⁄2 in. [40 mm] from any second
S2.1.3 The report of the ultrasonic examination shall be in surface. The purchaser may specify either duplicate no-break
compliance with the Report Section of Practice A 388/ performance when tested 10 deg warmer than a specified
A 388M. temperature or request a determination of the nil-ductility
S2.1.4 Additional nondestructive examination or trepanning temperature.

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 A 541/A 541M
S8. Restrictive Chemistry for Grades 4N and 5 P 0.012 % max heat, 0.015 % max product; Cu 0.10 % max
S8.1 Phosphorus and sulfur limits for Grades 4N and 5 may P 0.015 % max heat, 0.018 % max product; Cu 0.15 % max
be specified 0.020 %, max.
S13. Alternative Fracture Toughness Requirements
S9. Additional Vanadium
S13.1 The fracture toughness requirements (drop-weight or
S9.1 For Grade 5 forgings 0.05 to 0.15 % vanadium may be Charpy impact tests, or both) for materials of the ASME Boiler
specified.
and Pressure Vessel Code, Section III, Article NB2300,
S10. Special Steels NC2300, ND2300, NE2300, NF2300 or NG2300, as specified,
S10.1 Vacuum treated steel shall be specified. shall be used instead of the Charpy impact test requirements of
S10.2 When Grades 2, 3, 4N, and 5 are vacuum carbon this specification.
deoxidized, the silicon content shall be 0.10 % maximum.
S10.3 The test report shall indicate that the steel was vacuum S14. Alternative Test Specimen Orientation
carbon deoxidized. S14.1 The longitudinal axis of all test specimens shall be
oriented in a direction transverse to the direction of maximum
S11. Rings and Hollow Cylindrically Shaped Parts
working of the forging.
S11.1 Tests shall be removed in the tangential (circumfer-
ential) direction regardless of direction of maximum working. S15. Restricted Sulfur Content
S12. Restrictive Chemistry S15.1 The sulfur content shall be limited to 0.015 % maxi-
S12.1 The following restricted phosphorus and copper lim- mum heat and 0.018 % maximum product.
its may be specified as follows:

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