ASTM A990/A990M-23

Standard Specification for Castings, Iron-Nickel-Chromium and Nickel Alloys, Specially Controlled for Pressure-Retaining Parts for Corrosive Service

ABSTRACT
This specification covers iron-nickel-chromium and nickel alloy castings specially processed with restricted melt practices, weldability testing, and nondestructive examination (NDE) requirements for use in pressure retaining parts with corrosive service environments. The choice of manufacturing procedure to be used for producing the alloy castings shall be according to specified metallic contents. Materials shall conform to specified chemical composition and tensile property requirements, and weldability qualifications. Nondestructive examination requirements such as casting thickness shall be evaluated by visual, radiographic, and liquid penetrant inspection. Castings shall be repair welded and solution heat treated prior to final cleaning by blasting, and shall not be peened, plugged, or impregnated.
SCOPE
1.1 This specification covers iron-nickel-chromium and nickel alloy castings specially processed with restricted melt practices, weldability testing, and nondestructive examination (NDE) requirements.  
1.2 A number of grades of iron-nickel-chromium and nickel alloy castings are included in this specification. Since these grades possess varying degrees of suitability for service in corrosive environments, it is the responsibility of the purchaser to determine which grade shall be furnished. Selection will depend on design and service conditions, mechanical properties, and corrosion-resistant characteristics.  
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 nonconformance with the standard.  
1.3.1 This specification is expressed in both inch-pound units and in SI units; however, unless the purchase order or contract specifies the applicable M-specification designation (SI units), the inch-pound units shall apply. Within the text, the SI units are shown in brackets.  
1.4 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 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.

General Information

• Status: Published
• Publication Date: 31-Oct-2023
• ICS: 77.120.40 - Nickel, chromium and their alloys
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.18 - Castings

Relations

• Replaces: ASTM A990/A990M-21 - Standard Specification for Castings, Iron-Nickel-Chromium and Nickel Alloys, Specially Controlled for Pressure-Retaining Parts for Corrosive Service
• Effective Date: 01-Nov-2023
• Refers: ASTM A488/A488M-24 - Standard Practice for Steel Castings, Welding, Qualifications of Procedures and Personnel
• Effective Date: 01-Mar-2024
• Refers: ASTM A903/A903M-99(2024) - Standard Specification for Steel Castings, Surface Acceptance Standards, Magnetic Particle and Liquid Penetrant Inspection
• Effective Date: 01-Mar-2024
• Refers: ASTM A903/A903M-99(2017) - Standard Specification for Steel Castings, Surface Acceptance Standards, Magnetic Particle and Liquid Penetrant Inspection
• Effective Date: 15-Mar-2017
• Referred By: ASTM A985/A985M-21 - Standard Specification for Steel Investment Castings General Requirements, for Pressure-Containing Parts
• Effective Date: 01-Nov-2023
• Referred By: ASTM A703/A703M-20a - Standard Specification for Steel Castings, General Requirements, for Pressure-Containing Parts
• Effective Date: 01-Nov-2023
• Referred By: ASTM A488/A488M-18e2 - Standard Practice for Steel Castings, Welding, Qualifications of Procedures and Personnel
• Effective Date: 01-Nov-2023

Overview

ASTM A990/A990M-23 is a standard specification developed by ASTM International that covers the requirements for castings made from iron-nickel-chromium and nickel alloys designed for pressure-retaining parts in corrosive service environments. This specification ensures that alloy castings are produced with restricted melting processes, subjected to rigorous weldability qualifications, and assessed through non-destructive examinations (NDE) to ensure high performance and safety in aggressive industrial settings. These castings are commonly used where superior mechanical properties and enhanced resistance to corrosion are essential.

Key Topics

• Material Grades and Composition

  • The specification includes multiple grades of iron-nickel-chromium and nickel alloys, each offering different degrees of corrosion resistance and mechanical properties.
  • Conformance to strict chemical composition limits is required for each heat of material, ensuring predictable alloy behavior in service.

• Manufacturing and Processing

  • Approved processes include electric arc or induction furnace melting, followed by advanced refining techniques (AOD or VOD) or melting of refined ingot.
  • No reclaimed or revert material is permitted except for certain nickel-based copper alloys.
  • Heat treatment procedures are specified for most grades to optimize microstructure and corrosion performance.

• Nondestructive Examination (NDE)

  • Four classes of NDE are detailed, combining visual inspection, radiographic analysis, and liquid penetrant testing, each with clearly defined acceptance criteria.
  • The required NDE class is to be specified by the purchaser; otherwise, the default Class D is applied.

• Weldability and Repair

  • Mandatory weldability qualification for each heat ensures that materials can be reliably joined and repaired.
  • All weld repairs must follow qualified welding procedures and use designated filler materials.
  • Solution heat treatment is required after significant weld repairs to restore corrosion resistance and mechanical properties.

Applications

• Pressure-Retaining Equipment

  • Essential for components such as valves, pump bodies, and piping systems operating under pressure in chemical processing, offshore, power generation, and other corrosive environments.

• Corrosive Service

  • Ideally suited for use where resistance to seawater, acids, alkalis, and other aggressive media is vital to preventing equipment failure and ensuring operational safety.

• Industries Served

  • Chemical processing
  • Oil and gas (offshore platforms, refineries)
  • Power generation, including nuclear
  • Marine and desalination plants
  • Specialty manufacturing requiring high-integrity cast components

Related Standards

• ASTM A351/A351M - Austenitic castings for pressure-containing parts
• ASTM A703/A703M - General requirements for steel castings for pressure-containing parts
• ASTM A985/A985M - Steel investment castings for pressure-containing parts
• ASTM A494/A494M - Nickel and nickel alloy castings
• ASTM A743/A743M & A744/A744M - Iron-chromium-nickel corrosion-resistant castings
• ASTM A488/A488M - Welding qualifications for steel castings
• ASME/ANSI B16.34 - Valves, flanged, threaded, and welding end
• AWS Standards - Welding filler materials for nickel and stainless steels

By specifying ASTM A990/A990M-23, purchasers and manufacturers ensure that critical pressure-retaining cast components provide reliable service life and superior corrosion resistance in demanding applications. This standard supports international best practices in material selection, quality assurance, and regulatory compliance for pressure equipment in corrosive service.

Standards Content (Sample)

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.
Designation: A990/A990M − 23
Standard Specification for
Castings, Iron-Nickel-Chromium and Nickel Alloys, Specially
Controlled for Pressure-Retaining Parts for Corrosive
Service
This standard is issued under the fixed designation A990/A990M; 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* 2. Referenced Documents
1.1 This specification covers iron-nickel-chromium and 2.1 ASTM Standards:
nickel alloy castings specially processed with restricted melt A351/A351M Specification for Castings, Austenitic, for
practices, weldability testing, and nondestructive examination Pressure-Containing Parts
(NDE) requirements. A488/A488M Practice for Steel Castings, Welding, Qualifi-
cations of Procedures and Personnel
1.2 A number of grades of iron-nickel-chromium and nickel
A494/A494M Specification for Castings, Nickel and Nickel
alloy castings are included in this specification. Since these
Alloy
grades possess varying degrees of suitability for service in
A703/A703M Specification for Steel Castings, General
corrosive environments, it is the responsibility of the purchaser
Requirements, for Pressure-Containing Parts
to determine which grade shall be furnished. Selection will
A743/A743M Specification for Castings, Iron-Chromium,
depend on design and service conditions, mechanical
Iron-Chromium-Nickel, Corrosion Resistant, for General
properties, and corrosion-resistant characteristics.
Application
1.3 The values stated in either SI units or inch-pound units
A744/A744M Specification for Castings, Iron-Chromium-
are to be regarded separately as standard. The values stated in
Nickel, Corrosion Resistant, for Severe Service
each system may not be exact equivalents; therefore, each
A802/A802M Practice for Steel Castings, Surface Accep-
system shall be used independently of the other. Combining
tance Standards, Visual Examination
values from the two systems may result in nonconformance
A903/A903M Specification for Steel Castings, Surface Ac-
with the standard.
ceptance Standards, Magnetic Particle and Liquid Pen-
1.3.1 This specification is expressed in both inch-pound
etrant Inspection
units and in SI units; however, unless the purchase order or
A985/A985M Specification for Steel Investment Castings
contract specifies the applicable M-specification designation
General Requirements, for Pressure-Containing Parts
(SI units), the inch-pound units shall apply. Within the text, the
E94/E94M Guide for Radiographic Examination Using In-
SI units are shown in brackets.
dustrial Radiographic Film
1.4 This standard does not purport to address all of the E165/E165M Practice for Liquid Penetrant Testing for Gen-
safety concerns, if any, associated with its use. It is the
eral Industry
responsibility of the user of this standard to establish appro- E186 Reference Radiographs for Heavy-Walled (2 to 4 ⁄2 in.
priate safety, health, and environmental practices and deter-
(50.8 to 114 mm)) Steel Castings
mine the applicability of regulatory limitations prior to use. E272 Reference Radiographs for High-Strength Copper-
1.5 This international standard was developed in accor-
Base and Nickel-Copper Alloy Castings
dance with internationally recognized principles on standard- E280 Reference Radiographs for Heavy-Walled (4 ⁄2 to 12
ization established in the Decision on Principles for the
in. (114 to 305 mm)) Steel Castings
Development of International Standards, Guides and Recom- E446 Reference Radiographs for Steel Castings Up to 2 in.
mendations issued by the World Trade Organization Technical
(50.8 mm) in Thickness
Barriers to Trade (TBT) Committee.
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. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Nov. 1, 2023. Published November 2023. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1998. Last previous edition approved in 2021 as A990/A990M – 21. Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/A0990_A0990M-23. 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
A990/A990M − 23
2.2 AWS Standards: 4.2 Investment Castings—Material furnished to this specifi-
AWS A5.4 Specification for Stainless Steel Electrodes for cation shall conform to the requirements of Specification
Shielded Metal Arc Welding A985/A985M, including any supplementary requirements that
AWS A5.9 Specification for Bare Stainless Steel Welding are indicated in the purchase order. Failure to comply with the
Electrodes and Rods general requirements of Specification A985/A985M consti-
AWS A5.11/A5.11M Specification for Nickel and Nickel- tutes nonconformance with this specification. In case of con-
Alloy Welding Electrodes for Shielded Metal Arc Welding flict between the requirements of this specification and Speci-
AWS A5.14/A5.14M Specification for Nickel and Nickel- fication A985/A985M, Specification A985/A985M shall
Alloy Bare Welding Electrodes and Rods prevail.
2.3 ASME/ANSI Standard:
5. Ordering Information
ASME/ANSI B16.34 Valves—Flanged, Threaded, and
5.1 It is the responsibility of the purchaser to specify all
Welding End
requirements that are necessary for material ordered to this
3. Terminology specification. Such requirements may include, but are not
limited to, the following:
3.1 Definitions of Terms Specific to This Standard:
5.1.1 Quantity.
3.1.1 accessible surface, n—surface that can be welded on
5.1.2 Grade designation (Table 1).
without cutting access holes in the casting.
5.1.3 Description of the casting by pattern number or
3.1.2 refined ingot, n—metal processed by argon-oxygen-
drawing. Dimensional tolerances should be included on the
decarburization (AOD) or vacuum-oxygen-decarburization
casting drawing.
(VOD) and cast to a size and shape suitable for remelting.
5.1.4 Nondestructive inspection class required (Table 2).
3.1.3 revert, n—gates, risers, and castings. Also includes
Class D will be supplied unless otherwise specified.
scrapped machinery and fabricated items, chips, and turnings.
5.1.5 Wetted surfaces (Table 2).
5.2 The purchaser shall specify any supplementary require-
4. General Conditions for Delivery
ments desired, including standards of acceptance, required to
4.1 Other than investment castings, material furnished to
adequately describe the desired material.
this specification shall conform to the requirements of Speci-
fication A703/A703M, including any supplementary require- 6. Process and Manufacture
ments that are indicated in the purchase order. Failure to
6.1 Alloys, except for nickel-base alloys with 25 to 35 %
comply with the general requirements of Specification A703/
Cu, shall be made by one of the two following processes:
A703M constitutes nonconformance with this specification. In
6.1.1 Electric arc or induction furnace melting followed by
case of conflict between the requirements of this specification
AOD or VOD refining, or
and Specification A703/A703M, this specification shall pre-
6.1.2 Electric arc or induction furnace melting of refined
vail.
ingot.
6.2 Nickel-base alloys with 25 to 35 % Cu shall be made by
6.1.1 or 6.1.2 or by electric arc or induction melting of virgin
or primary metals.
Available from American Welding Society (AWS), 8669 NW 36 Street, #130,
Miami, FL 33166-6672, http://www.aws.org.
6.3 Additions of up to 5 % are permitted for compositional
Available from American Society of Mechanical Engineers (ASME), ASME
adjustments and deoxidation.
International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
www.asme.org.
A,B
TABLE 1 Chemical Requirements
Element, % Grade
CK3MCuN CN3MCu CW2M CW2MC M35-1 N2M
Carbon 0.025 0.030 0.020 0.020 0.35 0.020
Manganese 1.20 1.50 1.00 1.00 1.50 1.00
Silicon 0.75 1.00 0.80 0.45 1.25 0.80
Phosphorus 0.020 0.030 0.030 0.015 0.030 0.030
Sulfur 0.010 0.015 0.015 0.015 0.015 0.015
Molybdenum 6.0–7.0 2.0–3.0 15.0–17.5 8.0–10.0 . . . 30.0–33.0
Iron Balance Balance 2.00 5.0 3.5 3.00
Nickel 17.5–19.5 27.5–30.5 Balance Balance Balance Balance
Chromium 19.5–20.5 19.0–22.0 15.0–17.5 20.0–23.0 . . . 1.00
Nitrogen 0.18–0.24 . . . . . . . . . . . . . . .
Copper 0.50–1.00 3.0–3.5 . . . 0.50 26.0–33.0 0.20
Tungsten . . . . . . 1.00 0.50 . . . 0.20
Vanadium . . . . . . . . . 0.20 . . . 0.20
C
Niobium . . . . . . . . . 3.1–4.5 . . . . . .
A
Where ellipses (.) appear in this table, there is no requirement and the element need not be analyzed for or reported.
B
All values are maximums unless a range is provided.
C
Columbium (Cb) and niobium (Nb) are interchangeable names for the same element 41.
A990/A990M − 23
TABLE 2 Nondestructive Examination Requirements
Radiographic Examination, Liquid Penetrant Examination, Practice E165/E165M
Visual Examination, Practice
Guide E94/E94M Minimum Acceptance Level
Maximum Casting Thickness Class A802/A802M Minimum
Number of Castings Coverage per Specification
Acceptance Level
Severity Level per Table 6 A903/A903M
Less than ⁄8 in. [15.9 mm] A Level I 100 % All accessible surfaces Level II
B Level II 100 % All accessible wetted sur- Level II
faces
C Level II Initial casting off pattern Weld repairs Level II
D Level II Initial casting off pattern NA NA
⁄8 to 1 in. [15.9 to 25.4 mm] A Level I 100 % All accessible surfaces Level III
B Level II 100 % All accessible wetted sur- Level III
faces
C Level II Initial casting off pattern Weld repairs Level III
D Level II Initial casting off pattern NA NA
Over 1 to 2 in. [25.4 to 50.8 mm] A Level I 100 % All accessible surfaces Level IV
B Level II 100 % All accessible wetted sur- Level IV
faces
C Level II Initial casting off pattern Weld repairs Level IV
D Level II Initial casting off pattern NA NA
Over 2 to 4 ⁄2 in. [50.8 to 114 mm] A Level II 100 % All accessible surfaces Level IV
B Level II 100 % All accessible wetted sur- Level IV
faces
C Level III Initial casting off pattern Weld repairs Level V
D Level III Initial casting off pattern NA NA
Over 4 ⁄2 in. [114 mm] A Level III 100 % All accessible surfaces Level V
B Level III 100 % All accessible wetted sur- Level V
faces
C Level IV Initial casting off pattern Weld repairs Level V
D Level IV Initial casting off pattern NA NA
TABLE 4 Heat Treat Requirements
6.4 Revert shall not be used.
Grade Heat Treatment
CK3MCuN Heat to 2200 to 2265 °F [1205 to 1240 °C] for 1 h at temperature
per 1 in. [25 mm] of thickness with a minimum of 4 h. Quench in
7. Chemical Composition
A
water.
7.1 These alloys shall conform to the chemical composition CN3MCu Heat to 2050 °F [1120 °C] min for a min of 1 h at temperature per
A
1 in. [25 mm] of thickness. Quench in water.
requirements prescribed in Table 1. An analysis of every heat
CW2M Heat to 2225 to 2300 °F [1220 to 1260 °C] for a minimum of 1 h
is required. A
at temperature per 1 in. [25 mm] of thickness. Quench in water.
CW2MC Heat to 2175 °F [1190 °C] min for a min of 2 h at temperature or
a min of 1 h per 1 in. [25 mm] of thickness, whichever is greater.
8. Tensile Properties
A
Quench in water.
8.1 One tension test shall be made from each heat. Test M35-1 As-cast
N2M Heat to 2080 °F [1140 °C] min for a min of 2 h at temperature +
results shall conform to the tensile requirements specified in
A
1 h per 1 in. [25 mm] of thickness. Quench in water.
Table 3. The bar shall be solution heat treated per the
A
Quench in water or rapid cool by other means as agreed upon by the
requirements of Table 4 in production furnaces to the same
manufacturer and purchaser.
procedure as the castings it represents. If the casting grade does
not require heat treatment, the bar used for the test specimen
9. Weldability Qualification
shall not be heat treated.
9.1 Each heat shall be qualified by weldability testing.
9.2 Sampling:
A
TABLE 3 Tensile Requirements
9.2.1 The weldability test plate shall be cast in accordance
Tensile Strength, 0.2 % Offset Yield Elongation in 2 in.
Grade
B
with Fig. 1.
ksi [MPa] Strength, ksi [MPa] [50 mm], %
CK3MCuN 80 [550] 38 [260] 35
9.2.2 For heats produced under 6.1.1, at least one weldabil-
CN3MCu 62 [425] 25 [170] 35
ity test plate shall be cast from each heat.
CW2M 72 [495] 40 [275] 20
9.2.3 For heats produced under 6.1.2, at least one weldabil-
CW2MC 70 [485] 40 [275] 25
M35-1 65 [450] 25 [170] 25
ity test plate shall be cast from the first heat in an uninterrupted
N2M 76 [525] 40 [275] 20
series of heats, made in the same furnace from the same heat of
A
All values are minimums unless a range is provided.
refined ingot using the same melting procedure, and shall
B
When ICI test bars are used in tensile testing as provided for in Specification
qualify all of the subsequent heats in that series made in the
A985
...

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: A990/A990M − 21 A990/A990M − 23
Standard Specification for
Castings, Iron-Nickel-Chromium and Nickel Alloys, Specially
Controlled for Pressure-Retaining Parts for Corrosive
Service
This standard is issued under the fixed designation A990/A990M; 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 iron-nickel-chromium and nickel alloy castings specially processed with restricted melt practices,
weldability testing, and nondestructive examination (NDE) requirements.
1.2 A number of grades of iron-nickel-chromium and nickel alloy castings are included in this specification. Since these grades
possess varying degrees of suitability for service in corrosive environments, it is the responsibility of the purchaser to determine
which grade shall be furnished. Selection will depend on design and service conditions, mechanical properties, and
corrosion-resistant characteristics.
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 nonconformance with the standard.
1.3.1 This specification is expressed in both inch-pound units and in SI units; however, unless the purchase order or contract
specifies the applicable M-specification designation (SI units), the inch-pound units shall apply. Within the text, the SI units are
shown in brackets.
1.4 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, health, and environmental practices and determine the applicability of
regulatory limitations prior to use.
1.5 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:
A351/A351M Specification for Castings, Austenitic, for Pressure-Containing Parts
A488/A488M Practice for Steel Castings, Welding, Qualifications of Procedures and Personnel
A494/A494M Specification for Castings, Nickel and Nickel Alloy
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 Nov. 1, 2021Nov. 1, 2023. Published November 2021November 2023. Originally approved in 1998. Last previous edition approved in 20202021
as A990/A990M – 20.A990/A990M – 21. DOI: 10.1520/A0990_A0990M-21.10.1520/A0990_A0990M-23.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. 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
A990/A990M − 23
A703/A703M Specification for Steel Castings, General Requirements, for Pressure-Containing Parts
A743/A743M Specification for Castings, Iron-Chromium, Iron-Chromium-Nickel, Corrosion Resistant, for General Application
A744/A744M Specification for Castings, Iron-Chromium-Nickel, Corrosion Resistant, for Severe Service
A802/A802M Practice for Steel Castings, Surface Acceptance Standards, Visual Examination
A903/A903M Specification for Steel Castings, Surface Acceptance Standards, Magnetic Particle and Liquid Penetrant
Inspection
A985/A985M Specification for Steel Investment Castings General Requirements, for Pressure-Containing Parts
E94/E94M Guide for Radiographic Examination Using Industrial Radiographic Film
E165/E165M Practice for Liquid Penetrant Testing for General Industry
E186 Reference Radiographs for Heavy-Walled (2 to 4 ⁄2 in. (50.8 to 114 mm)) Steel Castings
E272 Reference Radiographs for High-Strength Copper-Base and Nickel-Copper Alloy Castings
E280 Reference Radiographs for Heavy-Walled (4 ⁄2 to 12 in. (114 to 305 mm)) Steel Castings
E446 Reference Radiographs for Steel Castings Up to 2 in. (50.8 mm) in Thickness
2.2 AWS Standards:
AWS A5.4 Specification for Stainless Steel Electrodes for Shielded Metal Arc Welding
AWS A5.9 Specification for Bare Stainless Steel Welding Electrodes and Rods
AWS A5.11/A5.11M Specification for Nickel and Nickel-Alloy Welding Electrodes for Shielded Metal Arc Welding
AWS A5.14/A5.14M Specification for Nickel and Nickel-Alloy Bare Welding Electrodes and Rods
2.3 ASME/ANSI Standard:
ASME/ANSI B16.34 Valves—Flanged, Threaded, and Welding End
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 accessible surface, n—surface that can be welded on without cutting access holes in the casting.
3.1.2 refined ingot, n—metal processed by argon-oxygen-decarburization (AOD) or vacuum-oxygen-decarburization (VOD) and
cast to a size and shape suitable for remelting.
3.1.3 revert, n—gates, risers, and castings. Also includes scrapped machinery and fabricated items, chips, and turnings.
4. General Conditions for Delivery
4.1 Other than investment castings, material furnished to this specification shall conform to the requirements of Specification
A703/A703M, including any supplementary requirements that are indicated in the purchase order. Failure to comply with the
general requirements of Specification A703/A703M constitutes nonconformance with this specification. In case of conflict between
the requirements of this specification and Specification A703/A703M, this specification shall prevail.
4.2 Investment Castings—Material furnished to this specification shall conform to the requirements of Specification A985/A985M,
including any supplementary requirements that are indicated in the purchase order. Failure to comply with the general requirements
of Specification A985/A985M constitutes nonconformance with this specification. In case of conflict between the requirements of
this specification and Specification A985/A985M, Specification A985/A985M shall prevail.
5. Ordering Information
5.1 It is the responsibility of the purchaser to specify all requirements that are necessary for material ordered to this specification.
Such requirements may include, but are not limited to, the following:
5.1.1 Quantity.
5.1.2 Grade designation (Table 1).
5.1.3 Description of the casting by pattern number or drawing. Dimensional tolerances should be included on the casting drawing.
Available from American Welding Society (AWS), 8669 NW 36 Street, #130, Miami, FL 33166-6672, http://www.aws.org.
Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Two Park Ave., New York, NY 10016-5990, http://
www.asme.org.
A990/A990M − 23
A,B
TABLE 1 Chemical Requirements
Element, % Grade
CK3MCuN CN3MCu CW2M CW2MC M35-1 N2M
Carbon 0.025 0.030 0.020 0.020 0.35 0.020
Manganese 1.20 1.50 1.00 1.00 1.50 1.00
Silicon 0.75 1.00 0.80 0.45 1.25 0.80
Phosphorus 0.020 0.030 0.030 0.015 0.030 0.030
Sulfur 0.010 0.015 0.015 0.015 0.015 0.015
Molybdenum 6.0–7.0 2.0–3.0 15.0–17.5 8.0–10.0 . . . 30.0–33.0
Iron Balance Balance 2.00 5.0 3.5 3.00
Nickel 17.5–19.5 27.5–30.5 Balance Balance Balance Balance
Chromium 19.5–20.5 19.0–22.0 15.0–17.5 20.0–23.0 . . . 1.00
Nitrogen 0.18–0.24 . . . . . . . . . . . . . . .
Copper 0.50–1.00 3.0–3.5 . . . 0.50 26.0–33.0 0.20
Tungsten . . . . . . 1.00 0.50 . . . 0.20
Vanadium . . . . . . . . . 0.20 . . . 0.20
C
Niobium . . . . . . . . . 3.1–4.5 . . . . . .
A
Where ellipses (.) appear in this table, there is no requirement and the element need not be analyzed for or reported.
B
All values are maximums unless a range is provided.
C
Columbium (Cb) and niobium (Nb) are interchangeable names for the same element 41.
5.1.4 Nondestructive inspection class required (Table 2). Class D will be supplied unless otherwise specified.
5.1.5 Wetted surfaces (Table 2).
5.2 The purchaser shall specify any supplementary requirements desired, including standards of acceptance, required to adequately
describe the desired material.
6. Process and Manufacture
6.1 Alloys, except for nickel base, nickel-base alloys with 25 to 35 % Cu alloys, Cu, shall be made by one of the two following
processes:
TABLE 2 Nondestructive Examination Requirements
Radiographic Examination, Liquid Penetrant Examination, Practice E165/E165M
Visual Examination, Practice
Guide E94/E94M Minimum Acceptance Level
Maximum Casting Thickness Class A802/A802M Minimum
Number of Castings Coverage per Specification
Acceptance Level
Severity Level per Table 6 A903/A903M
Less than ⁄8 in. [15.9 mm] A Level I 100 % All accessible surfaces Level II
B Level II 100 % All accessible wetted sur- Level II
faces
C Level II Initial casting off pattern Weld repairs Level II
D Level II Initial casting off pattern NA NA
⁄8 to 1 in. [15.9 to 25.4 mm] A Level I 100 % All accessible surfaces Level III
B Level II 100 % All accessible wetted sur- Level III
faces
C Level II Initial casting off pattern Weld repairs Level III
D Level II Initial casting off pattern NA NA
Over 1 to 2 in. [25.4 to 50.8 mm] A Level I 100 % All accessible surfaces Level IV
B Level II 100 % All accessible wetted sur- Level IV
faces
C Level II Initial casting off pattern Weld repairs Level IV
D Level II Initial casting off pattern NA NA
Over 2 to 4 ⁄2 in. [50.8 to 114 mm] A Level II 100 % All accessible surfaces Level IV
B Level II 100 % All accessible wetted sur- Level IV
faces
C Level III Initial casting off pattern Weld repairs Level V
D Level III Initial casting off pattern NA NA
Over 4 ⁄2 in. [114 mm] A Level III 100 % All accessible surfaces Level V
B Level III 100 % All accessible wetted sur- Level V
faces
C Level IV Initial casting off pattern Weld repairs Level V
D Level IV Initial casting off pattern NA NA
A990/A990M − 23
6.1.1 Electric arc or induction furnace melting followed by AOD or VOD refining, or
6.1.2 Electric arc or induction furnace melting of refined ingot.
6.2 Nickel base Nickel-base alloys with 25 to 35 % Cu shall be made by 6.1.1 or 6.1.2 or by electric furnace.arc or induction
melting of virgin or primary metals.
6.3 Additions of up to 5 % are permitted for compositional adjustments and deoxidation.
6.4 Revert shall not be used.
7. Chemical Composition
7.1 These alloys shall conform to the chemical composition requirements prescribed in Table 1. An analysis of every heat is
required.
8. Tensile Properties
8.1 One tension test shall be made from each heat. Test results shall conform to the tensile requirements specified in Table 3. The
bar shall be solution heat treated per the requirements of Table 4 in production furnaces to the same procedure as the castings it
represents. If the casting grade does not require heat treatment, the bar used for the test specimen shall not be heat treated.
9. Weldability Qualification
9.1 Each heat shall be qualified by weldability testing.
9.2 Sampling:
9.2.1 The weldability test plate shall be cast in accordance with Fig. 1.
9.2.2 For heats produced under 6.1.1, at least one weldability test plate shall be cast from each heat.
9.2.3 For heats produced under 6.1.2, at least one weldability test plate shall be cast from the first heat in an uninterrupted series
of heats, made in the same furnace from the same heat of refined ingot using the same melting procedure, and shall qualify all of
the subsequent heats in that series made in the same shift.
A
TABLE 3 Tensile Requirements
Tensile Strength, 0.2 % Offset Yield Elongation in 2 in.
Grade
B
ksi [MPa] Strength, ksi [MPa] [50 mm], %
CK3MCuN 80 [550] 38 [260] 35
CN3MCu 62 [425] 25 [170] 35
CW2M 72 [495] 40 [275] 20
CW2MC 70 [485] 40 [275] 25
M35-1 65 [450] 25 [170] 25
N2M 76 [525] 40 [275] 20
A
All values are minimums unless a range is provided.
B
When ICI test bars are used in tensile testing as provided for in Specification
A985/A985M, the gage length to reduced section diameter ratio shall be 4 to 1.
A990/A990M − 23
TABLE 4 Heat Treat Requirements
Grade Heat Treatment
CK3MCuN Heat to 2200 to 2265 °F [1205 to 1240 °C] for 1 h at temperature
per 1 in. [25 mm] of thickness with a minimum of 4 h. Quench in
A
water.
CN3MCu Heat to 2050 °F [1120 °C] min for a min of 1 h at temperature per
A
1 in. [25 mm] of thickness. Quench in water.
CW2M Heat to 2225 to 2300 °F [1220 to 1260 °C] for a minimum of 1 h
A
at temperature per 1 in. [25 mm] of thickness. Quench in water.
CW2MC Heat to 2175 °F [1190 °C] min for a min of 2 h at temperature or
a min of 1 h per 1 in. [25 mm] of thickness, whichever is greater.
A
Quench in water.
M35-1 As-cast
N2M Heat to 2080 °F [1140 °C] min for a min of 2 h at temperature +
A
1 h per 1 in. [25 mm] of thickness. Quench in water.
A
Quench in water or rapid cool by other means as agreed upon by the
manufacturer and purchaser.
(a)
M
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