ASTM A447/A447M-11(2021)

Standard Specification for Steel Castings, Chromium-Nickel-Iron Alloy (25-12 Class), for High-Temperature Service

ABSTRACT
This specification covers iron-base, heat-resisting alloy castings, intended for structural elements, containers, and supports in electric furnaces, petroleum still tube supports, and for similar applications. The alloys shall be electric-furnace processed and heat treated. The castings shall conform to the required chemical compositions of nickel, chromium, carbon, nitrogen, manganese, silicon, phosphorus, sulfur, and iron. The specimens shall undergo tension test after aging and short-time high-temperature tension test and shall conform to the required values of tensile strength and elongation. A stress-rupture test shall also be performed wherein the specimens shall conform to the required values of tensile stress. The specimen shall also conform to the required values of magnetic permeability.
SCOPE
1.1 This specification covers iron-base, heat-resisting alloy castings of the 25 % chromium, 12 % nickel class, intended for structural elements, containers, and supports in electric furnaces, petroleum still tube supports, and for similar applications up to 2000 °F [1095 °C].  
1.2 In the absence of significant proportions of elements other than those prescribed in Section 5, the two types of alloys covered by this specification may in general be distinguished as follows:  
1.2.1 Type I—Alloys characterized by relatively low limiting creep stress at temperatures between 1500 and 2000 °F [815 and 1095 °C], and relatively high ductility at ordinary temperatures after aging for short periods at temperatures between 1300 and 1500 °F [705 and 815 °C].  
1.2.2 Type II—Alloys having relatively high limiting creep stress but which may develop low ductility at ordinary temperatures when aged for short periods at temperatures between 1350 and 1500 °F [730 and 815 °C].  
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 Within the text, the SI units are shown in brackets.  
1.4 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: 30-Apr-2021
• ICS: 77.140.80 - Iron and steel castings
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.18 - Castings

Relations

• Refers: ASTM E8/E8M-24 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Jan-2024
• Refers: ASTM A800/A800M-20 - Standard Practice for Estimating Ferrite Content of Stainless Steel Castings Containing Both Ferrite and Austenite
• Effective Date: 01-May-2020
• Refers: ASTM A957/A957M-18a - Standard Specification for Investment Castings, Steel and Alloy, Common Requirements, for General Industrial Use
• Effective Date: 01-Sep-2018
• Refers: ASTM A781/A781M-18c - Standard Specification for Castings, Steel and Alloy, Common Requirements, for General Industrial Use
• Effective Date: 01-Sep-2018
• Refers: ASTM A781/A781M-18b - Standard Specification for Castings, Steel and Alloy, Common Requirements, for General Industrial Use
• Effective Date: 01-Jun-2018
• Refers: ASTM A781/A781M-18a - Standard Specification for Castings, Steel and Alloy, Common Requirements, for General Industrial Use
• Effective Date: 15-May-2018
• Refers: ASTM A957/A957M-18 - Standard Specification for Investment Castings, Steel and Alloy, Common Requirements, for General Industrial Use
• Effective Date: 15-May-2018
• Refers: ASTM A1067/A1067M-12a(2018) - Standard Specification for Test Coupons for Steel Castings
• Effective Date: 01-Mar-2018
• Refers: ASTM A781/A781M-18 - Standard Specification for Castings, Steel and Alloy, Common Requirements, for General Industrial Use
• Effective Date: 01-Jan-2018
• Refers: ASTM A781/A781M-17 - Standard Specification for Castings, Steel and Alloy, Common Requirements, for General Industrial Use
• Effective Date: 01-May-2017
• Refers: ASTM A781/A781M-16 - Standard Specification for Castings, Steel and Alloy, Common Requirements, for General Industrial Use
• Effective Date: 01-Dec-2016
• Refers: ASTM E8/E8M-16 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 15-Jul-2016
• Refers: ASTM A957/A957M-15a - Standard Specification for Investment Castings, Steel and Alloy, Common Requirements, for General Industrial Use
• Effective Date: 01-Nov-2015
• Refers: ASTM A957/A957M-15 - Standard Specification for Investment Castings, Steel and Alloy, Common Requirements, for General Industrial Use
• Effective Date: 01-Mar-2015
• Refers: ASTM E8/E8M-15 - Standard Test Methods for Tension Testing of Metallic Materials
• Effective Date: 01-Feb-2015

Overview

ASTM A447/A447M-11(2021) is the internationally recognized standard specification for steel castings made of chromium-nickel-iron alloy (25-12 class), designed for high-temperature service up to 2000 °F [1095 °C]. Developed by ASTM International, this standard details material, processing, and testing requirements for iron-base, heat-resisting alloy castings, particularly for use as structural elements, containers, and supports in electric furnaces and petroleum still tube supports, among other demanding industrial applications.

The specification outlines both chemical composition and mechanical property requirements, supporting the safe and reliable use of cast stainless steel components in environments exposed to extreme heat.

Key Topics

• Material Composition:
  Castings must conform to strict limits on key elements like nickel (10.00–14.00%), chromium (23.00–28.00%), and controls on carbon, nitrogen, manganese, silicon, phosphorus, and sulfur, ensuring performance at elevated temperatures.

• Alloy Types:

  • Type I: Known for low limiting creep stress at 1500-2000 °F [815-1095 °C] and high ductility after aging at 1300-1500 °F [705-815 °C].
  • Type II: Offers higher creep stress resistance but may have reduced ductility after similar aging.

• Mechanical & Physical Testing:

  • Tension tests after aging and at high temperature
  • Stress-rupture tests (sustaining specified loads at high temperatures for at least 16 hours)
  • Magnetic permeability tests, supporting identification of metallurgical structure

• Manufacturing Process:
  Alloys must be produced by the electric-furnace process or other processes approved by the purchaser. Heat treatment is only required if specified in the agreement.

• Dimensional & Quality Assurance:
  Ordering information must specify dimensions, applicable standard version, alloy type, and required supplementary requirements. Weld repairs are permitted but must be inspected to relevant quality standards, with post-weld heat treatment if specified.

Applications

ASTM A447/A447M high-temperature cast stainless steel components are essential in industries where structural stability, creep resistance, and corrosion resistance are critical under elevated temperatures, including:

• Electric Furnace Construction:
  Critical components such as supports, containment elements, and internal structures exposed to sustained high heat.

• Petroleum Processing:
  Tube supports, trays, and other components within petroleum stills where thermal cycling and aggressive atmospheres are common.

• General High-Temperature Service:
  Industrial process equipment subjected to temperatures up to 2000 °F, including support frames, brackets, and hardware in kilns, incubators, and refineries.

The specification enables manufacturers and purchasers to ensure component reliability, performance, and compliance with global trade and technical regulations.

Related Standards

Several ASTM standards are referenced for general requirements, testing, and supplementary practices. Key related standards include:

• ASTM A781/A781M: General requirements for steel and alloy castings
• ASTM A957/A957M: Specification for investment castings, steel and alloy
• ASTM A800/A800M: Practice for estimating ferrite content in stainless steel castings
• ASTM A1067/A1067M: Specification for test coupons for steel castings
• ASTM E8/E8M: Test methods for tension testing of metallic materials
• ASTM E21: Test methods for elevated-temperature tension tests of metallic materials

These standards collectively provide a comprehensive framework for the production, testing, and quality assurance of heat-resisting steel castings in demanding industrial settings.

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Keywords: ASTM A447, high-temperature steel castings, chromium-nickel-iron alloy, stainless steel, industrial furnaces, petroleum processing, material specification, creep resistance, tension testing, magnetic permeability, ASTM standards.

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: A447/A447M −11 (Reapproved 2021)
Standard Specification for
Steel Castings, Chromium-Nickel-Iron Alloy (25-12 Class),
for High-Temperature Service
This standard is issued under the fixed designationA447/A447M; 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-base, heat-resisting alloy 2.1 ASTM Standards:
castings of the 25 % chromium, 12 % nickel class, intended for A781/A781M Specification for Castings, Steel and Alloy,
Common Requirements, for General Industrial Use
structural elements, containers, and supports in electric
A800/A800M Practice for Estimating Ferrite Content of
furnaces, petroleum still tube supports, and for similar appli-
Stainless Steel Castings Containing Both Ferrite and
cations up to 2000 °F [1095 °C].
Austenite
1.2 In the absence of significant proportions of elements
A957/A957M Specification for Investment Castings, Steel
other than those prescribed in Section 5, the two types of alloys
and Alloy, Common Requirements, for General Industrial
coveredbythisspecificationmayingeneralbedistinguishedas
Use
follows:
A1067/A1067M Specification for Test Coupons for Steel
1.2.1 Type I—Alloys characterized by relatively low limit-
Castings
ing creep stress at temperatures between 1500 and 2000 °F
E8/E8M Test Methods for Tension Testing of Metallic Ma-
[815 and 1095 °C], and relatively high ductility at ordinary
terials
temperatures after aging for short periods at temperatures
E21 TestMethodsforElevatedTemperatureTensionTestsof
between 1300 and 1500 °F [705 and 815 °C]. Metallic Materials
1.2.2 Type II—Alloys having relatively high limiting creep
3. General Conditions for Delivery
stress but which may develop low ductility at ordinary tem-
peratures when aged for short periods at temperatures between
3.1 Except for investment castings, material furnished to
1350 and 1500 °F [730 and 815 °C].
this specification shall conform to the requirements of Speci-
fication A781/A781M, including any supplementary require-
1.3 The values stated in either SI units or inch-pound units
ments that are indicated in the purchase order. Failure to
are to be regarded separately as standard. The values stated in
comply with the general requirements of Specification A781/
each system may not be exact equivalents; therefore, each
A781M constitutes nonconformance with this specification. In
system shall be used independently of the other. Combining
case of conflict between the requirements of this specification
values from the two systems may result in nonconformance
and Specification A781/A781M, this specification shall pre-
with the standard.
vail.
1.3.1 Within the text, the SI units are shown in brackets.
3.2 Investment castings furnished to this specification shall
1.4 This international standard was developed in accor-
conform to the requirements of Specification A957/A957M,
dance with internationally recognized principles on standard-
including any supplementary requirements that are indicated in
ization established in the Decision on Principles for the
the purchase order. Failure to comply with the general require-
Development of International Standards, Guides and Recom-
ments of Specification A957/A957M constitutes nonconfor-
mendations issued by the World Trade Organization Technical
mance with this specification. In the case of conflict between
Barriers to Trade (TBT) Committee.
the requirements of this specification and Specification A957/
A957M, Specification A957/A957M shall prevail.
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 May 1, 2021. Published May 2021. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1944. Last previous edition approved in 2016 as A447/A447M – 11 Standards volume information, refer to the standard’s Document Summary page on
(2016). DOI: 10.1520/A0447_A0447M-11R21. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
A447/A447M − 11 (2021)
4. Ordering Information 8.4 In all cases, it shall be the manufacturer’s duty to
provide a sufficient number of samples for the specified tests.
4.1 The inquiry and order should include or indicate the
following:
9. Number of Tests
4.1.1 A description of the casting by pattern number or
9.1 The purchaser shall specify not more than two tests
drawing (dimensional tolerances shall be included on the
selected from the following list, with the restriction that not
casting drawing),
more than one of the tension tests at high temperature (that is,
4.1.2 Which standard (A447 or A447M) applies,
9.1.3 or 9.1.4) may be required:
4.1.3 The version of the alloy, that is, Type I or Type II, to
9.1.1 Tension test after aging,
be supplied (Sections 1, 11, 12, 13, and 14).
9.1.2 Magnetic permeability test,
4.1.4 Options in the specification (Section 9), and
9.1.3 Stress-rupture test, and
4.1.5 The supplementary requirements desired, including
9.1.4 Short-time, high-temperature tension test.
the standards of acceptance.
5. Process 10. Retests
5.1 The alloy for the castings shall be made by the electric- 10.1 Mechanical Tests—If any of the specimens first chosen
furnace process or by any other process approved by the for any of the mechanical tests agreed upon fails to conform to
purchaser. the specified requirements, an additional specimen from the
same melt may be tested. This additional specimen shall
6. Heat Treatment
conform to the requirements prescribed for the test in question.
6.1 Except as otherwise agreed upon between the manufac-
10.2 Magnetic Test—If the magnetic permeability of the
turer and the purchaser, the manufacturer shall not be required
specimen first tested does not conform to the requirement
to heat treat the castings.
prescribed in 12.1, three additional specimens from the same
melt may be tested. At least two of these shall conform to the
7. Chemical Composition
prescribed requirement.
7.1 The castings shall conform to the requirements of Table
1 as to chemical composition.
11. Tensile Properties After Aging
11.1 The tensile properties of the material after aging shall
8. Sampling
conform to the following requirements:
8.1 Material for the tests specified in Sections 11, 13, and 14
Type I Type II
may be taken from separately cast test blocks of a form such as
Tensile strength, min, ksi [MPa] 80 [550] 80 [550]
A
that shown in Fig. 2 of Specification A1067/A1067M, from
Elongation in 2 in. (4D), min, % 9 4
B
Elongation in 5D, min, % 8.7 3.9
another type of test block, from the castings, or from coupons
attached to the castings as may be agreed upon between the
A
These minima shall apply when tested according to Test Methods E8.
ma
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