ASTM A892 - 09 (2020)

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Designation: A892 −09 (Reapproved 2020)
Standard Guide for
Deﬁning and Rating the Microstructure of High Carbon
Bearing Steels
1
This standard is issued under the ﬁxed designation A892; 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 guide covers the description of carbide structures in
annealed high carbon bearing steels.
1.2 Included is a guide for rating steel specimens by a
graded series of photomicrographs showing the incidence of
certain conditions.
1.3 The reference photomicrographs are graded illustrations
of annealed carbides categorized by size, network, and lamellar
content (shape).
1.4 This guide is to facilitate communication and descrip-
tion of microstructure. It does not establish limits of accept-
ability. Such limits are a matter of agreement between user and
producer.
1.5 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
standard.
1.6 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 appro-
priate safety, health, and environmental practices and deter-
mine the applicability of regulatory limitations prior to use.
1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
2
E3 Guide for Preparation of Metallographic Specimens
E407 Practice for Microetching Metals and Alloys
E1245 Practice for Determining the Inclusion or Second-
Phase Constituent Content of Metals by Automatic Image
Analysis
2.2 ASTM Adjuncts:
3
Photomicrographs for Deﬁning and Rating the Microstruc-
ture of High Carbon Bearing Steels
3. Apparatus
3.1 In order to adequately compare the structure of a
specimen with the photomicrographs, it will be necessary to
view a properly prepared sample at 1000× magniﬁcation with
good resolution.
4. Specimen Preparation
4.1 Samples that represent a portion of the cross section of
the material shall be prepared using the practices described in
Guide E3. The size of the sample shall be negotiated between
the user and the producer. It may be a full cross section but
should not be too large for practical handling in the polishing
operation.
4.2 The properly polished specimens shall be etched in a
suitable etchant which will clearly delineate the annealed
carbide structure of the material being examined as described
in Practice E407. Nital (2 %) will frequently be an adequate
etchant for routine examination. When critical or detailed
analysis of structures is required, the recommended etchant is
Picral (saturated).
5. Description
5.1 The reference photomicrographs (available in ASTM
Adjunct ADJA0892
3
) are arranged into three categories, as
follows: carbide size (CS), carbide network (CN), and lamellar
content (LC).
5.2 Six photomicrographs for each category are provided
and are identiﬁed by category and number, for example,
CS1-CS6, CN1-CN6, and LC1-LC6. Higher numbers indicate
a larger number or greater degree of severity of the category
being rated.
1
This guide is under the jurisdiction of Committee A01 on Steel, Stainless Steel
and Related Alloys and is the direct responsibility of Subcommittee A01.28 on
Bearing and Power Transmission Steels.
Current edition approved March 1, 2020. Published March 2020. Originally
approved in 1988. Last previous edition approved in 2014 as A892–09 (2014)
ɛ1
.
DOI: 10.1520/A0892–09R20.
2
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.
3
Available from ASTM International Headquarters. Order Adjunct No.
ADJA0892. Original adjunct produced in 2009.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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.

5.2.1 Actual counted number of carbides per 400 µm

determined from the carbide size series of photomicrographs is

as follows (reported counts are the average of three measure-

ments):

CS1 508

CS2 419

CS3 324

CS4 234

CS5 165

CS6 115

6. Procedure for Evaluation

6.1 Using an optical metallograph and a magniﬁcation of

1000×, examine a properly prepared and etched specimen.

Select a ﬁeld which is representative of the category to be

graded and compare it to the photomicrographs which are part

of this method. The rating will be the number of that photo that

most closely resembles the appearance of the specimen. A

separate ﬁeld may be used for each category or a single ﬁeld

may be rated for more than one category. An example rating is

CS4, CN2, LC1.

6.2 As an alternate method, the rating of carbide size by

automatic image analysis shall be conducted in accordance

with Practice E1245. The rating shall be deﬁned by the

following equation:

Rating 56.7888 24.5924

(1)

where:

= number of carbides per mm

The results shall be rounded to the nearest integer value from

1to6.

7. Keywords

7.1 antifriction bearings; bearing steel; chromium alloy

steel; metallography

ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentioned

in this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the risk

of infringement of such rights, are entirely their own responsibility.

This standard is subject to revision at any time by the responsible technical committee and must be reviewed every ﬁve years and

if not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standards

and should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of the

responsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you should

make your views known to the ASTM Committee on Standards, at the address shown below.

This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,

United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the above

address or at 610-832-9585 (phone), 610-832-9555 (fax), or service@astm.org (e-mail); or through the ASTM website

(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222

Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http://www.copyright.com/

A892 − 09 (2020)

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摘要：

ASTM A892 - 09 (2020) 是一项由美国材料与试验协会（ASTM）发布的标准规范，主要针对高碳钢与合金钢中磨削等级（grinding grade）的微观结构评定方法进行定义与指导。该标准通过光学显微镜下的微观组织观察，对钢材料在磨削过程中可能产生的过热、马氏体变化、回火层等缺陷进行分类和评级，广泛应用于钢铁制造、机械加工、热处理及质量检验领域。2020年的再批准版本确认了其技术内容的持续有效性，确保在工业实践中对钢件表面完整性和性能评估具有一致的判定依据。该标准为材料工程师、质检

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