ASTM A892-06

Standard Guide for Defining and Rating the Microstructure of High Carbon Bearing Steels

ABSTRACT
This guide covers the definition and rating of the microstructure of carbide structures in annealed high carbon bearing steels. Requirements for the optical metallograph apparatus and specimen preparation including polishing and etching are detailed. The description of the reference photomicrographs (graded illustrations of annealed carbides categorized by size, network, and lamellar content (shape)) that shall be used in the evaluation and the equation that shall define the rating are given.
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 description of microstructure. It does not establish limits of acceptability. Such limits are a matter of agreement between user and producer.
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 and health practices and determine the applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 31-Aug-2006
• ICS: 77.140.20 - Stainless steels
• Technical Committee: A01 - Steel, Stainless Steel and Related Alloys
• Drafting Committee: A01.28 - Bearing and Power Transmission Steels

Relations

• Replaces: ASTM A892-88(2001) - Standard Guide for Defining and Rating the Microstructure of High Carbon Bearing Steels
• Effective Date: 01-Sep-2006
• Replaced By: ASTM A892-09 - Standard Guide for Defining and Rating the Microstructure of High Carbon Bearing Steels
• Effective Date: 01-Oct-2009
• Referred By: ASTM A295/A295M-14(2020) - Standard Specification for High-Carbon Anti-Friction Bearing Steel
• Effective Date: 01-Sep-2006

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information.
Designation: A892 – 06
Standard Guide for
Defining and Rating the Microstructure of High Carbon
1
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. 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* 4. Specimen Preparation
1.1 Thisguidecoversthedescriptionofcarbidestructuresin 4.1 Samples that represent a portion of the cross section of
annealed high carbon bearing steels. the material shall be prepared using the practices described in
1.2 Included is a guide for rating steel specimens by a Guide E3. The size of the sample shall be negotiated between
graded series of photomicrographs showing the incidence of the user and the producer. It may be a full cross section but
certain conditions. should not be too large for practical handling in the polishing
1.3 The reference photomicrographs are graded illustrations operation.
ofannealedcarbidescategorizedbysize,network,andlamellar 4.2 The properly polished specimens shall be etched in a
content (shape). suitable etchant which will clearly delineate the annealed
1.4 This guide is to facilitate communication and descrip- carbide structure of the material being examined as described
tion of microstructure. It does not establish limits of accept- in Practice E407. Nital (2 %) will frequently be an adequate
ability. Such limits are a matter of agreement between user and etchant for routine examination. When critical or detailed
producer. analysis of structures is required, the recommended etchant is
1.5 This standard does not purport to address all of the Picral (saturated).
safety concerns, if any, associated with its use. It is the
5. Description
responsibility of the user of this standard to establish appro-
5.1 The reference photomicrographs are arranged into three
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. categories, as follows: carbide size (CS), carbide network
(CN), and lamellar content (LC).
2. Referenced Documents
5.2 Six photomicrographs for each category are provided
2
2.1 ASTM Standards: and are identified by category and number, for example,
E3 Guide for Preparation of Metallographic Specimens CS1-CS6, CN1-CN6, and LC1-LC6 as shown in Figs. 1-3.
E407 Practice for Microetching Metals and Alloys Higher numbers indicate a larger number or greater degree of
E1245 Practice for Determining the Inclusion or Second- severity of the category being rated.
2
Phase Constituent Content of Metals by Automatic Image 5.2.1 Actual counted number of carbides per 400 µm
Analysis determined from the carbide size series of photomicrographs is
as follows (reported counts are the average of three measure-
3. Apparatus
ments):
3.1 In order to adequately compare the structure of a
CS1 508
specimen with the photomicrographs, it will be necessary to CS2 419
view a properly prepared sample at 10003 magnification with
CS3 324
good resolution. CS4 234
CS5 165
1
CS6 115
This guide is under the jurisdiction of CommitteeA01 on Steel, Stainless Steel
and Related Alloys and is the direct responsibility of Subcommittee A01.28 on
Bearing Steels. 6. Procedure for Evaluation
Current edition appr
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