ASTM B934-21

Standard Test Method for Effective Case Depth of Ferrous Powder Metallurgy (PM) Parts Using Microindentation Hardness Measurements

SIGNIFICANCE AND USE
5.1 The engineering function of many PM parts may require an exterior portion of the part to have a specified case depth and microindentation hardness. Measurement of effective case depth is used to determine the depth to which the microindentation hardness of the exterior portion of a part has been increased over that of the interior of the part.
SCOPE
1.1 This test method covers a procedure for determination of the effective case depth of powder metallurgy (PM) parts.  
1.2 A microindentation hardness traverse procedure is described to determine effective case depth. This test method may be used to determine the effective case depth for all types of hardened cases.  
1.3 The procedure for determining the microindentation hardness of powder metallurgy materials, as described in Test Method B933, shall be followed.  
1.4 Units—With the exception of the unit for density, for which the grams per cubic centimeter unit is the long-standing industry practice, the values in SI units are to be regarded as standard.  
1.5 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 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: 31-Mar-2021
• ICS: 77.160 - Powder metallurgy
• Technical Committee: B09 - Metal Powders and Metal Powder Products
• Drafting Committee: B09.05 - Structural Parts

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: B934 − 21
Standard Test Method for
Effective Case Depth of Ferrous Powder Metallurgy (PM)
1
Parts Using Microindentation Hardness Measurements
This standard is issued under the fixed designation B934; 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* E384 Test Method for Microindentation Hardness of Mate-
rials
1.1 This test method covers a procedure for determination
E691 Practice for Conducting an Interlaboratory Study to
of the effective case depth of powder metallurgy (PM) parts.
Determine the Precision of a Test Method
1.2 A microindentation hardness traverse procedure is de-
3
2.2 MPIF Standard:
scribedtodetermineeffectivecasedepth.Thistestmethodmay
Standard70 GuidetoSamplePreparationofFerrousPowder
be used to determine the effective case depth for all types of
Metallurgy (PM) Materials for Cross-Sectional Metallo-
hardened cases.
graphic Evaluation
1.3 The procedure for determining the microindentation
3. Terminology
hardness of powder metallurgy materials, as described in Test
Method B933, shall be followed.
3.1 Definitions of powder metallurgy (PM) terms can be
found in Terminology B243. Additional descriptive informa-
1.4 Units—With the exception of the unit for density, for
which the grams per cubic centimeter unit is the long-standing tion is available under “General Information on PM” on the
ASTM B09 web page.
industry practice, the values in SI units are to be regarded as
standard.
3.2 Definitions of Terms Specific to This Standard:
1.5 This standard does not purport to address all of the 3.2.1 case, n—that portion of a part, extending inward from
safety concerns, if any, associated with its use. It is the the surface that has a microindentation hardness, after
responsibility of the user of this standard to establish appro- hardening, equal to or greater than a specified hardness.
priate safety, health, and environmental practices and deter-
3.2.2 effective case depth, n—perpendicular distance from
mine the applicability of regulatory limitations prior to use.
the surface of the hardened case to the furthest point where a
1.6 This international standard was developed in accor-
microindentation hardness value equivalent to 50 HRC is
dance with internationally recognized principles on standard-
maintained, unless otherwise specified.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
4. Summary of Test Method
mendations issued by the World Trade Organization Technical
4.1 The powder metallurgy part is sectioned and the surface
Barriers to Trade (TBT) Committee.
prepared for examination. Microindentation hardness measure-
ments are taken at various depths below the part surface. The
2. Referenced Documents
distance where the microindentation hardness falls below the
2
2.1 ASTM Standards:
equivalent of 50 HRC is defined as the effective case depth,
B243 Terminology of Powder Metallurgy
unless otherwise specified.
B933 TestMethodforMicroindentationHardnessofPowder
Metallurgy (PM) Materials
5. Significance and Use
5.1 TheengineeringfunctionofmanyPMpartsmayrequire
an exterior portion of the part to have a specified case depth
1
This test method is under the jurisdiction of ASTM Committee B09 on Metal
and microindentation hardness. Measurement of effective case
Powders and Metal Powder Products and is the direct responsibility of Subcom-
depth is used to determine the depth to which the microinden-
mittee B09.05 on Structural Parts.
Current edition approved April 1, 2021. Published July 2021. Originally
tation hardness of the exterior portion of a part has been
approved in 2004. Last previous edition approved in 2015 as B934 – 15. DOI:
increased over that of the interior of the part.
10.1520/B0934-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
3
Standards volume information, refer to the standard’s Document Summary page on Available from Metal Powder Industries Federation (MPIF), 105 College Rd.
the ASTM website. East, Princeton, NJ 08540, http://www.mpif.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
1

---------------------- Page: 1 ----------------------
B934 − 21
6. Apparatus 8. Procedure
6.1 Knoop or Vickers Hardn
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: B934 − 15 B934 − 21
Standard Test Method for
Effective Case Depth of Ferrous Powder Metallurgy (PM)
1
Parts Using Microindentation Hardness Measurements
This standard is issued under the fixed designation B934; 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 test method covers a procedure for determination of the effective case depth of powder metallurgy (PM) parts.
1.2 A microindentation hardness traverse procedure is described to determine effective case depth. This test method may be used
to determine the effective case depth for all types of hardened cases.
1.3 The procedure for determining the microindentation hardness of powder metallurgy materials, as described in Test Method
B933, shall be followed.
1.4 Units—With the exception of the unit for density, for which the grams per cubic centimeter unit is the long-standing industry
practice, the values in SI units are to be regarded as standard.
1.5 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 safety, health, and healthenvironmental practices and determine the
applicability of regulatory limitations prior to use.
1.6 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.
2. Referenced Documents
2
2.1 ASTM Standards:
B243 Terminology of Powder Metallurgy
B933 Test Method for Microindentation Hardness of Powder Metallurgy (PM) Materials
E384 Test Method for Microindentation Hardness of Materials
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
3
2.2 MPIF Standard:
Standard 70 Guide to Sample Preparation of Ferrous Powder Metallurgy (PM) Materials for Cross-Sectional Metallographic
Evaluation
1
This test method is under the jurisdiction of ASTM Committee B09 on Metal Powders and Metal Powder Products and is the direct responsibility of Subcommittee B09.05
on Structural Parts.
Current edition approved Oct. 1, 2015April 1, 2021. Published November 2015July 2021. Originally approved in 2004. Last previous edition approved in 20102015 as
B934 – 10.B934 – 15. DOI: 10.1520/B0934-15.10.1520/B0934-21.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
3
Available from Metal Powder Industries Federation (MPIF), 105 College Rd. East, Princeton, NJ 08540, http://www.mpif.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
1

---------------------- Page: 1 ----------------------
B934 − 21
3. Terminology
3.1 Definitions of powder metallurgy (PM) terms can be found in Terminology B243. Additional descriptive information is
available in the Related Material section of Volume 02.05 of the under “General Information on PM” on the Annual Book of ASTM
Standards.ASTM B09 web page.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 case, —n—that portion of a part, extending inward from the surface that has a microindentation hardness, after hardening,
equal to or greater than a specified hardness.
3.2.2 effective case depth—depth, n—perpendicular distance from the surface of the hardened case to the furthest point where a
microindentation hardness value equivalent to 50 HRC is maintained, unless otherwise specified.
4. Summary of Test Method
4.1 The powder metallurgy part is sectioned and the surface prepared for examination. Microindentation hardness measurements
are taken at various depths below the part surface. The distance where the microindentation hardness falls below the equivalent
of 50 HRC is defined as the effective case depth, unless otherwise specified.
5. Significance and Use
5.1 The engineering function of many PM parts may require an exterior portion of the part to have a sp
...