ASTM A743/A743M-21

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: A743/A743M − 19 A743/A743M − 21
Standard Specification for
Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion
Resistant, for General Application
This standard is issued under the fixed designation A743/A743M; 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 U.S. Department of Defense.
1. Scope*
1.1 This specification covers iron-chromium and iron-chromium-nickel alloy castings for general corrosion-resistant application.
The grades covered by this specification represent types of alloy castings suitable for broad ranges of application which are
intended for a wide variety of corrosion environments.
NOTE 1—For alloy castings for severe corrosion-resistant service, reference should be made to Specification A744/A744M. For general heat-resistant alloy
castings, reference should be made to Specification A297/A297M. For nickel alloy castings for corrosion-resistant service, reference should be made to
Specification A494/A494M.
1.2 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, 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.
Inch-pound units are applicable for material ordered to Specification A743 and SI units for material ordered to Specification
A743M.
1.3 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
A262 Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels
A297/A297M Specification for Steel Castings, Iron-Chromium and Iron-Chromium-Nickel, Heat Resistant, for General
Application
A494/A494M Specification for Castings, Nickel and Nickel Alloy
A744/A744M Specification for Castings, Iron-Chromium-Nickel, Corrosion Resistant, for Severe Service
A781/A781M Specification for Castings, Steel and Alloy, Common Requirements, for General Industrial Use
A890/A890M Specification for Castings, Iron-Chromium-Nickel-Molybdenum Corrosion-Resistant, Duplex (Austenitic/
Ferritic) for General Application
This specification is under the jurisdiction of ASTM Committee A01 on Steel, Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee A01.18
on Castings.
Current edition approved March 1, 2019March 1, 2021. Published March 2019March 2021. Originally approved in 1977. Last previous edition approved in 20172019 as
A743/A743M – 17.A743/A743M – 19. DOI: 10.1520/A0743_A0743M-19.10.1520/A0743_A0743M-21.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
*A Summary 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
A743/A743M − 21
A957/A957M Specification for Investment Castings, Steel and Alloy, Common Requirements, for General Industrial Use
3. General Conditions for Delivery
3.1 Except for investment castings, castings furnished to this specification shall conform to the requirements of Specification
A781/A781M, including any supplementary requirements that are indicated on the purchase order. Failure to comply with the
general requirements of Specification A781/A781M constitutes nonconformance with this specification. In case of conflict between
the requirements of this specification and Specification A781/A781M, this specification shall prevail.
3.2 Steel investment castings furnished to this specification shall conform to the requirements of Specification A957/A957M,
including any supplementary requirements that are indicated in the purchase order. Failure to comply with the general requirements
of Specification A957/A957M constitutes nonconformance with this specification. In case of conflict between the requirements of
this specification and Specification A957/A957M, Specification A957/A957M shall prevail.
4. Ordering Information
4.1 Orders for material to this specification should include the following, as required, to describe the material adequately:
4.1.1 Description of the casting by pattern number or drawing,
4.1.2 Grade,
4.1.3 Heat treatment,
4.1.4 Options in the specification,
4.1.5 Whether castings are to be produced using the investment casting process, and
4.1.6 Supplementary requirements desired, including the standards of acceptance.
5. Process
5.1 The steel shall be made by the electric furnace process, with or without separate refining such as argon-oxygen decarburization
(AOD).
6. Heat Treatment
6.1 Castings shall be heat treated in accordance with the requirements in Table 1.
NOTE 2—Proper heat treatment of these alloys is usually necessary to enhance corrosion resistance and, in some cases, to meet mechanical properties.
Minimum heat treat temperatures are specified; however, it is sometimes necessary to heat treat at higher temperatures, hold for some minimum time at
temperature, and then rapidly cool the castings in order to enhance the corrosion resistance and meet mechanical properties.
7. Chemical Requirements
7.1 The chemical requirements are shown in Table 2.
A,B
TABLE 2 Chemical Requirements
Material Grade Element, %
Type
C
Carbon Manganese Phosphorus Sulfur Silicon Chromium Nickel Molybdenum Nitrogen Copper Niobium Other
(UNS)
CA6N 0.06 0.50 0.02 0.02 1.00 10.5–12.5 6.0–8.0 . . . . . . . . . . . . . . .
11Cr-7Ni
CA6NM 0.06 1.00 0.04 0.03 1.00 11.5–14.0 3.5–4.5 0.40–1.0 . . . . . . . . . . . .
12Cr-4Ni
(J91540)
A743/A743M − 21
TABLE 1 Heat Treatment Requirements
Grade Heat Treatment
CA6N Heat to 1900 °F [1040 °C], air cool, reheat to 1500 °F [815 °C], air cool, and age at 800 °F [425 °C], holding at
each temperature sufficient time to heat casting uniformly to temperature.
CA6NM Heat to 1850 °F [1010 °C] minimum, air cool to 200 °F [95 °C] or lower prior to any optional intermediate temper
and prior to the final temper. The final temper shall be between 1050 °F [565 °C] and 1150 °F [620 °C].
CA15, CA15M, CA40, CA40F (1) Heat to 1750 °F [955 °C] minimum, air cool and temper at 1100 °F [595 °C] minimum, or
(2) Anneal at 1450 °F [790 °C] minimum.
CA28MWV (1) Heat to 1875–1925 °F [1025–1050 °C], quench in air or oil, and temper at 1150 °F [620 °C] minimum, or
(2) Anneal at 1400 °F [760 °C] minimum.
CB30, CC50 (1) Heat to 1450 °F [790 °C] minimum, and air cool, or
(2) Heat to 1450 °F [790 °C] minimum, and furnace cool.
CB6 Heat between 1800 °F [980 °C] and 1920 °F [1050 °C], forced air, cool to 120 °F [50 °C] maximum, and temper
between 1100 °F and 1160 °F [595 °C and 625 °C].
CE30, CH10, CH20, CK20 Heat to 2000 °F [1093 °C] minimum, hold for sufficient time to heat casting to temperature, quench in water or
rapid cool by other means.
CF3, CF3M, CF3MN (1) Heat to 1900 °F [1040 °C] minimum, hold for sufficient time to heat casting to temperature, quench in water or
rapid cool by other means.
(2) As cast if corrosion resistance is acceptable.
CF8, CF8C, CF8M, CF16F, CF16Fa, Heat to 1900 °F [1040 °C] minimum, hold for sufficient time to heat casting to temperature, quench in water or
CF20, CG3M, CG8M, CG12 rapid cool by other means.
CF10SMnN Heat to 1950 °F [1065 °C] minimum, hold for sufficient time to heat casting to temperature, quench in water or
rapid cool by other means.
CK3MCuN, CK35MN, CN3M, CN3MN Heat to 2200 °F [1200 °C] minimum, hold for 4 h minimum, quench in water or rapid cool by other means.
CG6MMN, CN7M Heat to 2050 °F [1120 °C] minimum, hold for sufficient time to heat casting to temperature, quench in water or
rapid cool by other means.
CN7MS Heat to 2100 °F [1150 °C] minimum, 2150 °F [1180 °C] maximum, hold for sufficient time (2 h minimum) to heat
casting to temperature and quench in water.
HG10MNN As cast
TABLE 2 Continued
Material Grade Element, %
Type
C
Carbon Manganese Phosphorus Sulfur Silicon Chromium Nickel Molybdenum Nitrogen Copper Niobium Other
(UNS)
CA15 0.15 1.00 0.04 0.04 1.50 11.5–14.0 1.00 0.50 . . . . . . . . . . . .
12 Cr
(J91150)
CA15M 0.15 1.00 0.040 0.040 0.65 11.5–14.0 1.0 0.15–1.0 . . . . . . . . . . . .
12 Cr
(J91151)
CA28MWV 0.20–0.28 0.50–1.00 0.030 0.030 1.0 11.0–12.5 0.50–1.00 0.90–1.25 . . . . . . . . . V:
12Cr-Mo-W-V 0.20–0.30
(J91422) W:
0.90–1.25
CA40 0.20–0.40 1.00 0.04 0.04 1.50 11.5–14.0 1.0 0.5 . . . . . . . . . . . .
12 Cr
(J91153)
D
CA40F 0.20–0.40 1.00 0.04 0.20–0.40 1.50 11.5–14.0 1.0 0.5 . . . . . . . . . . . .
12 Cr
(J91154)
CB6 0.06 1.00 0.04 0.03 1.00 15.5–17.5 3.5–5.5 0.5 . . . . . . . . . . . .
16Cr-4Ni
(J91804)
E
CB30 0.30 1.00 0.04 0.04 1.50 18.0–21.0 2.00 . . . . . . . . . . . .
20 Cr
(J91803)
CC50 0.50 1.00 0.04 0.04 1.50 26.0–30.0 4.00 . . . . . . . . . . . . . . .
28 Cr
(J92615)
CE30 0.30 1.50 0.04 0.04 2.00 26.0–30.0 8.0–11.0 . . . . . . . . . . . . . . .
29Cr-9Ni
(J93423)
CF3 0.03 1.50 0.04 0.04 2.00 17.0–21.0 8.0–12.0 . . . . . . . . . . . . . . .
19Cr-9Ni
(J92500)
A743/A743M − 21
A,B
TABLE 2 Chemical Requirements
Material Grade Element, %
Type
C
Carbon Manganese Phosphorus Sulfur Silicon Chromium Nickel Molybdenum Nitrogen Copper Niobium Other
(UNS)
CA6N 0.06 0.50 0.02 0.02 1.00 10.5–12.5 6.0–8.0 . . . . . . . . . . . . . . .
11Cr-7Ni
CA6NM 0.06 1.00 0.04 0.03 1.00 11.5–14.0 3.5–4.5 0.40–1.0 . . . . . . . . . . . .
12Cr-4Ni
(J91540)
CA15 0.15 1.00 0.04 0.04 1.50 11.5–14.0 1.00 0.50 . . . . . . . . . . . .
12 Cr
(J91150)
CA15M 0.15 1.00 0.040 0.040 0.65 11.5–14.0 1.0 0.15–1.0 . . . . . . . . . . . .
12 Cr
(J91151)
CA28MWV 0.20–0.28 0.50–1.00 0.030 0.030 1.0 11.0–12.5 0.50–1.00 0.90–1.25 . . . . . . . . . V:
12Cr-Mo-W-V 0.20–0.30
(J91422) W:
0.90–1.25
CA40 0.20–0.40 1.00 0.04 0.04 1.50 11.5–14.0 1.0 0.5 . . . . . . . . . . . .
12 Cr
(J91153)
D
CA40F 0.20–0.40 1.00 0.04 0.20–0.40 1.50 11.5–14.0 1.0 0.5 . . . . . . . . . . . .
12 Cr
(J91154)
CB6 0.06 1.00 0.04 0.03 1.00 15.5–17.5 3.5–5.5 0.5 . . . . . . . . . . . .
16Cr-4Ni
(J91804)
E
CB30 0.30 1.00 0.04 0.04 1.50 18.0–21.0 2.00 . . . . . . . . . . . .
20 Cr
(J91803)
CC50 0.50 1.00 0.04 0.04 1.50 26.0–30.0 4.00 . . . . . . . . . . . . . . .
28 Cr
(J92615)
CE30 0.30 1.50 0.04 0.04 2.00 26.0–30.0 8.0–11.0 . . . . . . . . . . . . . . .
29Cr-9Ni
(J93423)
CF3 0.03 1.50 0.04 0.04 2.00 17.0–21.0 8.0–12.0 . . . . . . . . . . . . . . .
19Cr-9Ni
(J92500)
CF3M 0.03 1.50 0.04 0.04 1.50 17.0–21.0 9.0–13.0 2.0–3.0 . . . . . . . . . . . .
19Cr-10Ni-Mo
(J92800)
CF3MN 0.03 1.50 0.040 0.040 1.50 17.0–22.0 9.0–13.0 2.0–3.0 0.10–0.20 . . . . . . . . .
19Cr-10Ni-Mo-N
(J92804)
CF8 0.08 1.50 0.04 0.04 2.00 18.0–21.0 8.0–11.0 . . . . . . . . . . . . . . .
19Cr-9Ni
(J92600)
F
CF8C 0.08 1.50 0.04 0.04 2.00 18.0–21.0 9.0–12.0 . . . . . . . . . . . .
19Cr-10Ni-Nb
(J92710)
CF8M 0.08 1.50 0.04 0.04 2.00 18.0–21.0 9.0–12.0 2.0–3.0 . . . . . . . . . . . .
19Cr-10Ni-Mo
(J92900)
CF10SMnN 0.10 7.00–9.00 0.060 0.030 3.50–4.50 16.0–18.0 8.0–9.0 . . . 0.08–0.18 . . . . . . . . .
17Cr-8.4Ni-N
(J92972)
A743/A743M − 21
TABLE 2 Continued
Material Grade Element, %
Type
C
Carbon Manganese Phosphorus Sulfur Silicon Chromium Nickel Molybdenum Nitrogen Copper Niobium Other
(UNS)
D
CF16F 0.16 1.50 0.17 0.04 2.00 18.0–21.0 9.0–12.0 1.50 . . . . . . . . . Se:
19Cr-9Ni
0.20–0.35
(J92701)
D
CF16Fa 0.16 1.50 0.04 0.20–0.40 2.00 18.0–21.0 9.0–12.0 0.40–0.80 . . . . . . . . . . . .
19Cr-9Ni
CF20 0.20 1.50 0.04 0.04 2.00 18.0–21.0 8.0–11.0 . . . . . . . . . . . . . . .
19Cr-9Ni
(J92602)
CG3M 0.03 1.50 0.04 0.04 1.50 18.0–21.0 9.0–13.0 3.0–4.0 . . . . . . . . . . . .
19Cr-11Ni-Mo
(J92999)
CG6MMN 0.06 4.00–6.00 0.04 0.03 1.00 20.5–23.5 11.5–13.5 1.50–3.00 0.20–0.40 . . . 0.10–0.30 V:
(J93790) 0.10–0.30
CG8M 0.08 1.50 0.04 0.04 1.50 18.0–21.0 9.0–13.0 3.0–4.0 . . . . . . . . . . . .
19Cr-11Ni-Mo
(J93000)
CG12 0.12 1.50 0.04 0.04 2.00 20.0–23.0 10.0–13.0 . . . . . . . . . . . . . . .
22Cr-12Ni
(J93001)
CH10 0.10 1.50 0.04 0.04 2.00 22.0–26.0 12.0–15.0 . . . . . . . . . . . . . . .
25Cr-12 Ni
(J93401)
CH20 0.20 1.50 0.04 0.04 2.00 22.0–26.0 12.0–15.0 . . . . . . . . . . . . . . .
25Cr-12Ni
(J93402)
CK35MN 0.035 2.00 0.035 0.020 1.00 22.0–24.0 20.0–22.0 6.0–6.8 0.21–0.32 0.40 . . . . . .
23Cr-21Ni-Mo-N
CK3MCuN 0.025 1.20 0.045 0.010 1.00 19.5–20.5 17.5–19.5 6.0–7.0 0.180–0.240 0.50–1.00 . . . . . .
20Cr-18Ni-Cu-Mo
(J93254)
CK20 0.20 2.00 0.04 0.04 2.00 23.0–27.0 19.0–22.0 . . . . . . . . . . . . . . .
25Cr-20Ni
(J94202)
CN3M 0.03 2.0 0.03 0.03 1.0 20.0–22.0 23.0–27.0 4.5–5.5 . . . . . . . . . . . .
(J94652)
CN3MN 0.03 2.00 0.040 0.010 1.00 20.0–22.0 23.5–25.5 6.0–7.0 0.18–0.26 0.75 . . . . . .
21Cr-24Ni-Mo-N
(J94651)
CN7M 0.07 1.50 0.04 0.04 1.50 19.0–22.0 27.5–30.5 2.0–3.0 . . . 3.0–4.0 . . . . . .
20Cr-29Ni-Cu-Mo
(N08007)
CN7MS 0.07 1.00 0.04 0.03 2.50–3.50 18.0–20.0 22.0–25.0 2.5–3.0 1.5–2.0 . . . . . .
19Cr-24Ni-Cu-Mo
(J94650)
G
HG10MNN 0.07–0.11 3.0–5.0 0.040 0.030 0.70 18.5–20.5 11.5–13.5 0.25–0.45 0.20–0.30 0.50 . . .
19Cr-12Ni-4Mn
J92604
A
All values are maximums except where a range is provided.
B
Where ellipses (.) appear in this table, there is no requirement, and the element need not be analyzed for or reported.
C
Columbium (Cb) and niobium (Nb) are interchangeable names for the same element 41.
D
Free machining grade.
E
For Grade CB30, a copper content of 0.90 to 1.20 % is optional.
F
Grade CF8C shall have a niobium content of not less than eight times the carbon content and not more than 1.0 %. If a niobium-plus-tantalum alloy in the approximate
Nb:Ta ratio of 3:1 is used for stabilizing this grade, the total niobium-plus-tantalum content shall not be less than nine times the carbon content and shall not exceed 1.1 %.
G
Grade HG10MNN shall have a niobium content of not less than eight times the carbon, but not over 1.00 %.
A743/A743M − 21
TABLE 2 Continued
Material Grade Element, %
Type
C
Carbon Manganese Phosphorus Sulfur Silicon Chromium Nickel Molybdenum Nitrogen Copper Niobium Other
(UNS)
CF3M 0.03 1.50 0.04 0.04 1.50 17.0–21.0 9.0–13.0 2.0–3.0 . . . . . . . . . . . .
19Cr-10Ni-Mo
(J92800)
CF3MN 0.03 1.50 0.040 0.040 1.50 17.0–22.0 9.0–13.0 2.0–3.0 0.10–0.20 . . . . . . . . .
19Cr-10Ni-Mo-N
(J92804)
CF8 0.08 1.50 0.04 0.04 2.00 18.0–21.0 8.0–11.0 . . . . . . . . . .
...