ASTM B795-07
(Test Method)Standard Test Method for Determining the Percentage of Alloyed or Unalloyed Iron Contamination Present in Powder Forged (PF) Steel Materials
Standard Test Method for Determining the Percentage of Alloyed or Unalloyed Iron Contamination Present in Powder Forged (PF) Steel Materials
SIGNIFICANCE AND USE
Cross product contamination occurs whenever alloy steel powders are processed in the same equipment as iron powders.
Unalloyed iron particles, because they may not harden upon heat treatment, are a potential source of soft spots in low-alloy steel parts.
Alloyed iron particles, having higher hardenability than an iron or carbon steel matrix, are a potential source of hard spots.
Hard or soft spots may cause problems in service or machining.
The results of the tests may be used to qualify parts for shipment in accordance with guidelines agreed between purchaser and manufacturer or to check the suitability of mixes for use in powder forging.
SCOPE
1. Scope
1.1 This test method covers a metallographic procedure for determining the percentage of alloyed or unalloyed iron contamination present in powder forged low-alloy steel materials and the percentage of alloyed iron contamination in powder forged iron and carbon steel materials.
1.2 Property values stated in SI units are the standard.
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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Designation: B795 − 07
StandardTest Method for
Determining the Percentage of Alloyed or Unalloyed Iron
Contamination Present in Powder Forged (PF) Steel
1
Materials
This standard is issued under the fixed designation B795; 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* 4.2 The polished and etched sample is examined micro-
scopically at a magnification of 100× and a systematic point
1.1 This test method covers a metallographic procedure for
count made of features with etching characteristics different
determining the percentage of alloyed or unalloyed iron
from that of the matrix.
contamination present in powder forged low-alloy steel mate-
rials and the percentage of alloyed iron contamination in
4.3 The amount of contaminant is reported as a percentage
powder forged iron and carbon steel materials. to the nearest 0.1%.
1.2 Property values stated in SI units are the standard.
5. Significance and Use
1.3 This standard does not purport to address all of the
5.1 Cross product contamination occurs whenever alloy
safety concerns, if any, associated with its use. It is the
steel powders are processed in the same equipment as iron
responsibility of the user of this standard to establish appro-
powders.
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. 5.2 Unalloyed iron particles, because they may not harden
upon heat treatment, are a potential source of soft spots in
2. Referenced Documents
low-alloy steel parts.
2
2.1 ASTM Standards:
5.3 Alloyed iron particles, having higher hardenability than
B243Terminology of Powder Metallurgy
an iron or carbon steel matrix, are a potential source of hard
E3Guide for Preparation of Metallographic Specimens
spots.
3. Terminology
5.4 Hard or soft spots may cause problems in service or
3.1 Definitions—Definitions of powder metallurgy terms
machining.
can be found in Terminology B243. Additional descriptive
5.5 The results of the tests may be used to qualify parts for
information is available in the Related Material Section of Vol
shipment in accordance with guidelines agreed between pur-
02.05 of the Annual Book of ASTM Standards.
chaserandmanufacturerortocheckthesuitabilityofmixesfor
3.2 Definitions of Terms Specific to This Standard:
use in powder forging.
3.2.1 cross product contamination—the unintentional mix-
6. Apparatus
ing of powders with distinct differences in chemical composi-
tion.
6.1 Equipment for the metallographic preparation of test
specimens.
4. Summary of Test Method
6.2 A metallographic microscope permitting observation
4.1 Asection representing the core region is taken from the
and measurement at a magnification of 100×.
powder forged material and prepared for metallographic ex-
amination.
7. Sampling
7.1 Takeametallographicspecimenfromthepowderforged
1
This test method is under the jurisdiction of ASTM Committee B09 on Metal
material. The polished surface of the specimen should be not
Powders and Metal Powder Productsand is the direct responsibility of Subcommit-
tee B09.11 on Near Full Density Powder Metallurgy Materials.
less than that required to superimpose 2500 grid points at a
Current edition approved Oct. 1, 2007. Published November 2007. Originally
magnificationof100×.Multiplesectionsarepermittedinorder
e1
approved in 1988. Last previous edition approved in 2002 as B795–93(2002) .
to obtain the necessary area for measurement on small parts or
DOI: 10.1520/B0795-07.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or test pieces.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
7.2 The polished surface shall be parallel to the direction of
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. forging, that is, parallel to the direction of travel of the forging
*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 ----------------------
B795 − 07
punch, or as specified in the contract or purchase order, and (that is, a field of view) of the polished and etched specimen.
shall represent an area away from the surface of the material. Count and record the number of grid points falling upon
contaminant particles; if necessary, a separate count may be
8. Procedure
kept to distinguish between alloy contamination and unalloyed
8.1 Preparation of Specimens:
iron contamination in low-alloy steel materials, or, types of
8.1.1 Polishing—In polish
...
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.
e1
Designation:B795–93 (Reapproved 2002) Designation: B 795 – 07
Standard Test Method for
Determining the Percentage of Alloyed or Unalloyed Iron
Contamination Present in Powder Forged (P/F)(PF) Steel
1
PartsMaterials
This standard is issued under the fixed designation B 795; 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 (e) indicates an editorial change since the last revision or reapproval.
1
e NOTE—Titles of referenced documents were updated and paragraphs 4.3, 6.2, 7.1, and 8.1.2 were revised editorially in June
2002.
1. Scope*
1.1 This test method covers a metallographic procedure for determining the percentage of alloyed or unalloyed iron
contaminationpresentinpowderforgedlow-alloysteelpartsmaterialsandthepercentageofalloyedironcontaminationinpowder-
forged iron and carbon steel parts.materials.
1.2 Property values stated in SI units are the standard. Conversion factors to inch-pound units may be approximate.
1.3 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.
2. Referenced Documents
2
2.1 ASTM Standards:
B 243 Terminology of Powder Metallurgy
E 3Practice for Preparation of Metallographic Specimens
3
E562Test Method for Determining Volume Fraction by Systematic Manual Point Count Guide for Preparation of
Metallographic Specimens
3. Terminology
3.1 Definitions—Definitions of powder metallurgy terms can be found in Terminology B 243. Additional descriptive
information is available in the Related Material Section of Vol 02.05 of the Annual Book of ASTM Standards.
3.2 Description of Term Specific to This Standard:
3.2.1 cross product contamination—the unintentional mixing of powders with distinct differences in chemical composition.
4. Summary of Test Method
4.1 A section representing the core region of the part is taken from the powder forged partmaterial and prepared for
metallographic examination.
4.2 The polished and etched sample is examined microscopically at a magnification of 1003 and a systematic point count made
of features with etching characteristics different from that of the matrix.
4.3 The amount of contaminant is reported as a percentage to the nearest 0.1 %.
5. Significance and Use
5.1 Cross product contamination occurs whenever alloy steel powders are processed in the same equipment as iron powders.
5.2 Unalloyed iron particles, because they may not harden upon heat treatment, are a potential source of soft spots in low-alloy
steel parts.
1
This specification is under the jurisdiction of ASTM Committee B09 on Metal Powders and Metal Powder Products and is the direct responsibility of Subcommittee
B09.11 on Near-Full Density Powder Metallurgy Materials.
Current edition approved July 15, 1993. Published December 1993. Originally published as B795–88. Last previous edition B795–88.
1
ThistestmethodisunderthejurisdictionofASTMCommitteeB09onMetalPowdersandMetalPowderProductsandisthedirectresponsibilityofSubcommitteeB09.11
on Near Full Density Powder Metallurgy Materials.
e1
Current edition approved Oct. 1, 2007. Published November 2007. Originally approved in 1988. Last previous edition approved in 2002 as B 795 – 93(2002) .
2
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
, Vol 02.05.volume information, refer to the standard’s Document Summary page on the ASTM website.
*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 ----------------------
B795–07
5.3 Alloyed iron particles, having higher hardenability than an iron or carbon steel matrix, are a potential source of hard spots.
5.4 Hard or soft spots may cause problems in service or machining.
5.5The results of the tests may be used to qualify parts for shipment in accordance with guidelines agreed between purchaser
and manufacturer.
5.5 The results of the tests may be used to qualify parts for shipment in accordance with guidelines agreed between purchaser
and manufacturer or to check the suitability of mixes for use in powder forgi
...
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