ASTM A756-17(2022)
(Specification)Standard Specification for Stainless Anti-Friction Bearing Steel
Standard Specification for Stainless Anti-Friction Bearing Steel
ABSTRACT
This specification deals with the requirements for chromium-carbon bearing quality stainless steel to be used in the manufacture of anti-friction bearings. Chemical requirements shall conform to the required compositions of carbon, manganese, phosphorus, sulfur, silicon, chromium, nickel, copper, and molybdenum. Heat analysis and product analysis shall made. Decarburization and surface imperfection limits are specified. When annealing will be made, the steel should have a completely spheroidized microstructure and the hardness is specified.
SCOPE
1.1 This specification covers the requirements for chromium-carbon bearing quality stainless steel to be used in the manufacture of anti-friction bearings.
1.2 Supplementary Requirements of an optional nature are provided and when desired shall be so stated in the order.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
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
Relations
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: A756 −17 (Reapproved 2022)
Standard Specification for
Stainless Anti-Friction Bearing Steel
This standard is issued under the fixed designation A756; 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* 2.2 Other Standards:
ISO 683 Part 17 Ball and Roller Bearing Steels
1.1 This specification covers the requirements for
SAE J418a Grain Size Determination of Steel
chromium-carbon bearing quality stainless steel to be used in
the manufacture of anti-friction bearings.
3. Ordering Information
1.2 Supplementary Requirements of an optional nature are
3.1 Orders for material under specification should include
provided and when desired shall be so stated in the order.
the following information:
1.3 The values stated in inch-pound units are to be regarded
3.1.1 Quantity,
as standard. The values given in parentheses are mathematical
3.1.2 Grade identification,
conversions to SI units that are provided for information only
3.1.3 Specification designation and year of issue,
and are not considered standard.
3.1.4 Dimensions, shape, and
3.1.5 Supplementary Requirements, if desired.
1.4 This international standard was developed in accor-
dance with internationally recognized principles on standard-
4. Process
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 4.1 The steel shall be made by a process that is capable of
providing a high-quality product meeting the requirements of
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. this specification.
5. Chemical Composition
2. Referenced Documents
5.1 Typical examples of chemical compositions are shown
2.1 ASTM Standards:
in Table 1. Other compositions may be specified.
A484/A484M Specification for General Requirements for
Stainless Steel Bars, Billets, and Forgings
5.2 An analysis of each heat of steel shall be made by the
A751 Test Methods and Practices for Chemical Analysis of
steel manufacturer in accordance with Test Methods and
Steel Products
Practices A751. The chemical composition thus determined
E45 Test Methods for Determining the Inclusion Content of
shall conform to the requirements specified in Table 1 for the
Steel
ordered grade or to requirements agreed upon between the
E381 Method of Macroetch Testing Steel Bars, Billets,
manufacturer and the purchaser.
Blooms, and Forgings
5.3 Product analysis may be made by the purchaser in
E1019 Test Methods for Determination of Carbon, Sulfur,
accordancewithTestMethodsandPracticesA751.Permissible
Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt
variations in product analysis shall be made in accordance with
Alloys by Various Combustion and Inert Gas Fusion
Specification A484/A484M.
Techniques
E1077 Test Methods for Estimating the Depth of Decarbur-
6. Dimensions, Mass, and Permissible Variations
ization of Steel Specimens
6.1 The size and shape of the material shall be agreed upon
between manufacturer and purchaser.
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
6.2 Dimensional tolerances for hot-rolled or hot-rolled and
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
annealed bars, in straight lengths or coils, and cold-finished
A01.28 on Bearing Steels.
Current edition approved March 1, 2022. Published March 2022. Originally
approved in 1978. Last previous edition approved in 2017 as A756 – 17. DOI:
10.1520/A0756-17R22. Available from International Organization for Standardization (ISO), ISO
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva,
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Switzerland, http://www.iso.org.
Standards volume information, refer to the standard’s Document Summary page on Available from SAE International (SAE), 400 Commonwealth Dr.,Warrendale,
the ASTM website. PA 15096, http://www.sae.org.
*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
A756 − 17 (2022)
A, B
TABLE 1 Chemical Composition
P S Cu O
C
ISO Name C Mn Si Cr Ni Mo Al (max) Other
D
(max) (max) (max) (max)
... 440C 0.95–1.20 1.00 max 0.040 0.030 1.00 max 16.00–18.00 0.75 max 0.40–0.65 0.50 0.0020 0.050 ...
... X30CrMoN15-1 0.25–0.35 1.00 max 0.030 0.025 1.00 max 14.00–16.00 0.30–0.50 0.85–1.10 ... 0.0020 ... N
0.300–0.500
ISO X47Cr14 0.43–0.50 1.00 max 0.040 0.015 1.00 max 12.50–14.50 . . . 0.0020 . .
ISO X65Cr14 0.60–0.70 1.00 max 0.040 0.015 1.00 max 12.50–14.50 . 0.75 max . 0.0020 . .
ISO X108CrMo17 0.95–1.20 1.00 max 0.040 0.015 1.00 max 16.00–18.00 . 0.40–0.80 . 0.0020 . .
ISO X40CrMoVN16-2 0.37–0.45 0.60 max 0.025 0.015 0.60 max 15.00–16.50 0.30 max 1.50–1.90 . . . V
0.20–0.40
ISO X89CrMoV18-1 0.85–0.95 1.00 max 0.040 0.015 1.00 max 17.00–19.00 . 0.90–1.30 . 0.0020 . V
0.07–0.12
A
Elements not quoted shall not be intentionally added to the steel without the agreement of the purchaser.
B
Intentional additions of calcium or calcium alloys for deoxidation or inclusion shape control are not permitted unless specifically approved by the purchaser.
C
Steels listed as ISO meet the requirements of ISO 683, Part 17, Third Edition, Table 3.
D
Oxygen content applies to product analysis and shall be determined in accordance with Test Methods E1019.
bars0.500in.(12.7mm)andlargerindiameterfurnishedunder 7.2.3 For strand cast products, a minimum of six samples
thisspecificationshallconformtotherequirementsspecifiedin representing the first, middle, and last portion of the heat cast
the latest edition of Specification A484/A484M. shall be examined. At least one sample shall be taken from
each strand.
6.3 Dimensional tolerances for cold-finished coils for ball
and roller material shall be as shown in Table 2.
7.3 Macroetch—Specimens representative of the full cross
section of bars, billets, or blooms shall be macroetched and
6.4 Coil tolerances also apply to cold-finished straight
rated in accordance with Method E381 in hydrochloric acid
lengths under 0.500 in. (12.7 mm) in diameter.
and water (1:1) at a temperature of 160 °F to 180 °F (71 °C to
7. Quality Tests 82 °C). Such specimens shall not exceedS2, R2, C2of Method
E381. Indications due to sulfur segregation (commonly re-
7.1 The supplier shall be held responsible for the quality of
ferred to as Type A segregates) are not to be included in the
the material furnished and shall make the necessary tests to
rating.Foringotcastmaterialonly,ifthesizeandweightofthe
ensure this quality. The supplier shall be required to report on
bars, billets, or blooms prevent the full cross section from
the results of the macroetch and microinclusion rating tests
being macroetched, an oversize quarter-section may be used as
detailed below. Quality tests shown in 7.2 through 7.4 are
an alternative. The quarter-section must meet the reduction
based upon procedures established in Test Methods E45.
requirement of 7.2 and contain both the surface and center of
7.2 Sampling—Samples taken in accordance with the fol-
the original cross section before reduction.
lowing paragraphs shall be obtained from 4 in. by 4 in.
3 3
7.4 Inclusion Rating—The specimens shall be ⁄8 in. by ⁄4
(102 mm by 102 mm) rolled billets or forged sections. Tests
in. (9.5 mm by 19.1 mm) and shall be taken from an area
may be made on smaller or larger sections by agreement with
halfway between the center and outside of the billet. The
the purchaser. A minimum 3 to 1 reduction of rolled billets or
polished face shall be longitudinal to the direction of rolling.
forged sections is required for strand cast products.
The scale used for rating the specimens shall be the Jernkon-
7.2.1 For top poured products, a minimum of six samples
toret chart described in Test Methods E45, Plate I-A. Fields
representing the top and bottom of first, middle, and last usable
with sizes or numbers of all types of inclusions intermediate
ingots shall be examined.
between configurations shown on the chart shall be classified
7.2.2 For bottom poured products, a minimum of six
as the lesser of the rating number. The worst field of each
samples shall be examined and they shall represent
...
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