ASTM B797-93(2007)
(Test Method)Standard Test Method for Surface Finger Oxide Penetration Depth and Presence of Interparticle Oxide Networks in Powder Forged (P/F) Steel Parts
Standard Test Method for Surface Finger Oxide Penetration Depth and Presence of Interparticle Oxide Networks in Powder Forged (P/F) Steel Parts
SIGNIFICANCE AND USE
The presence of surface finger oxide penetration and interparticle oxide networks are two of the properties used to evaluate powder forged steel parts for proper processing. Maximum acceptable depths of penetration of surface finger oxide penetration and acceptable concentrations of subsurface interparticle oxide networks depend on the component and its service environment.
Results of tests may be used to qualify parts for shipment.
SCOPE
1.1 This test method covers a metallographic method for determining the maximum depth of surface finger oxide penetration and the concentration of subsurface interparticle oxide networks in critical areas of powder forged steel parts.
1.2 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.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation:B797 −93(Reapproved 2007)
Standard Test Method for
Surface Finger Oxide Penetration Depth and Presence of
Interparticle Oxide Networks in Powder Forged (P/F) Steel
Parts
This standard is issued under the fixed designation B797; 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 4.2 For surface finger oxide penetration, the polished and
unetched sample is examined microscopically at a magnifica-
1.1 This test method covers a metallographic method for
tion of 400×. The maximum depth of penetration of surface
determining the maximum depth of surface finger oxide
finger oxides is measured.
penetration and the concentration of subsurface interparticle
oxide networks in critical areas of powder forged steel parts. 4.3 For interparticle oxide network concentration, the pol-
ished and unetched sample is examined microscopically at a
1.2 This standard does not purport to address all of the
magnification of 200 to 400× to determine the presence of
safety concerns, if any, associated with its use. It is the
interparticle oxide networks.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
5. Significance and Use
bility of regulatory limitations prior to use.
5.1 The presence of surface finger oxide penetration and
2. Referenced Document
interparticle oxide networks are two of the properties used to
evaluate powder forged steel parts for proper processing.
2.1 ASTM Standards:
Maximum acceptable depths of penetration of surface finger
E3 Guide for Preparation of Metallographic Specimens
oxide penetration and acceptable concentrations of subsurface
3. Terminology interparticle oxide networks depend on the component and its
service environment.
3.1 Definitions of Terms Specific to This Standard:
3.1.1 surface finger oxides—surface finger oxides are sur- 5.2 Results of tests may be used to qualify parts for
face oxides that follow prior particle boundaries into a powder
shipment.
forged part from the surface and cannot be removed by
6. Apparatus
physical means such as rotary tumbling. Examples of surface
finger oxides are shown in Fig. 1.
6.1 Equipment for the metallographic preparation of test
specimens.
3.1.2 interparticle oxide networks—interparticle oxide net-
works are continuous or discontinuous oxides that follow prior
6.2 A metallographic microscope permitting observation
particle boundaries in powder forged parts. Examples of
and measurement up to a magnification of 400×.
interparticle oxide networks are shown in Fig. 2.
7. Sampling
4. Summary of Test Method
7.1 A metallographic specimen shall be removed from the
4.1 A section representing both surface and subsurface
powder forged part to cover each designated critical area.
regionsofacriticalareaiscutfromthepowderforgedpartand
Criticalareasshallbedefinedbytheapplicablepartdrawingor
mounted for metallographic grinding and polishing.
the purchaser order. Specimens shall be taken from the powder
forged part in the condition in which it is to be supplied. The
polished surface of the specimens shall be parallel to the
This test method is under the jurisdiction of ASTM Committee B09 on Metal
Powders and Metal Powder Products and is the direct responsibility of Subcom-
forging direction, that is, parallel to the direction of travel of
mittee B09.11 on Near Full Density Powder Metallurgy Materials.
the forging punch.
Current edition approved March 15, 2007. Published April 2007. Originally
approved in 1988. Last previous edition approved in 2002 as B797 – 93 (2002).
8. Procedure
DOI: 10.1520/B0797-93R07.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
8.1 Preparation of Specimens—In mounting the specimen
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
for grinding and polishing, protection from rounding the edge
Standards volume informatio
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