ASTM A892-09(2020)

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:A892 −09 (Reapproved 2020)
Standard Guide for
Defining and Rating the Microstructure of High Carbon
Bearing Steels
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.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope E407Practice for Microetching Metals and Alloys
E1245Practice for Determining the Inclusion or Second-
1.1 Thisguidecoversthedescriptionofcarbidestructuresin
Phase Constituent Content of Metals byAutomatic Image
annealed high carbon bearing steels.
Analysis
1.2 Included is a guide for rating steel specimens by a 3
2.2 ASTM Adjuncts:
graded series of photomicrographs showing the incidence of
Photomicrographs for Defining and Rating the Microstruc-
certain conditions.
ture of High Carbon Bearing Steels
1.3 The reference photomicrographs are graded illustrations
3. Apparatus
ofannealedcarbidescategorizedbysize,network,andlamellar
content (shape). 3.1 In order to adequately compare the structure of a
specimen with the photomicrographs, it will be necessary to
1.4 This guide is to facilitate communication and descrip-
view a properly prepared sample at 1000× magnification with
tion of microstructure. It does not establish limits of accept-
good resolution.
ability.Suchlimitsareamatterofagreementbetweenuserand
producer.
4. Specimen Preparation
1.5 The values stated in SI units are to be regarded as
4.1 Samples that represent a portion of the cross section of
standard. No other units of measurement are included in this
the material shall be prepared using the practices described in
standard.
Guide E3. The size of the sample shall be negotiated between
1.6 This standard does not purport to address all of the
the user and the producer. It may be a full cross section but
safety concerns, if any, associated with its use. It is the
should not be too large for practical handling in the polishing
responsibility of the user of this standard to establish appro-
operation.
priate safety, health, and environmental practices and deter-
4.2 The properly polished specimens shall be etched in a
mine the applicability of regulatory limitations prior to use.
suitable etchant which will clearly delineate the annealed
1.7 This international standard was developed in accor-
carbide structure of the material being examined as described
dance with internationally recognized principles on standard-
in Practice E407. Nital (2%) will frequently be an adequate
ization established in the Decision on Principles for the
etchant for routine examination. When critical or detailed
Development of International Standards, Guides and Recom-
analysis of structures is required, the recommended etchant is
mendations issued by the World Trade Organization Technical
Picral (saturated).
Barriers to Trade (TBT) Committee.
5. Description
2. Referenced Documents
5.1 The reference photomicrographs (available in ASTM
2.1 ASTM Standards:
Adjunct ADJA0892 ) are arranged into three categories, as
E3Guide for Preparation of Metallographic Specimens
follows:carbidesize(CS),carbidenetwork(CN),andlamellar
content (LC).
This guide is under the jurisdiction of Committee A01 on Steel, Stainless Steel 5.2 Six photomicrographs for each category are
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