ASTM A247-17

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: A247 − 17
Standard Test Method for
1
Evaluating the Microstructure of Graphite in Iron Castings
This standard is issued under the fixed designation A247; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2. Referenced Documents
2
1.1 This test method covers the classification of graphite in 2.1 ASTM Standards:
cast irons in terms of type, distribution, and size by visual E3Guide for Preparation of Metallographic Specimens
comparisontoreferencephotomicrographs.Thistestmethodis
2.2 ASTM Adjuncts:
intended to be applicable for all iron-carbon alloys containing Iron Casting Graphite Microstructure Rating Chart (Wall
3
graphite particles, and may be applied to gray irons, malleable
Chart)
irons, compacted graphite irons, and the ductile (nodular)
3. Summary of Test Method
irons.
3.1 The reference micrographs included in this standard
1.2 The reference photomicrographs included in this test
form the basis for classification. Characteristic features of
method are in no way to be construed as specifications. In an
graphite particle shape and distribution are designated by
appropriate specification for a specific material where graphite
numerals and letters. Type, distribution, and size of observed
microstructure is an important consideration, this test method
graphitearecomparedwiththeidealizedmicrostructuresinthe
may be used as a reference to concisely define the graphite
standard charts and rated accordingly as closely as possible to
microstructure required.
the equal or similar microstructures in the charts.
1.3 These reference photomicrographs are offered primarily
to permit accurate reporting of microstructures of cast irons
4. Significance and Use
and to facilitate the comparison of reports by different labora-
4.1 The comparison of observed graphite particles with the
tories or investigators.
structures shown in the charts give only purely descriptive
1.4 The values stated in SI units are to be regarded as
informationonthetype,distribution,andsizeofthegraphitein
standard. No other units of measurement are included in this
the sample being evaluated. It does not indicate, except in a
standard.
very broad way, the origin of the graphite or the suitability of
the iron-carbon alloy for a particular service.
1.5 This standard does not purport to address all of the
safety concerns, if any, associated with its use. It is the
5. Test Specimens or Samples
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica- 5.1 The preferred sample is a section cut from an actual
casting that is being evaluated at a location agreed upon
bility of regulatory limitations prior to use.
between the manufacturer and purchaser. When this is
1.6 This international standard was developed in accor-
impractical, a test lug or projection often can be appended to
dance with internationally recognized principles on standard-
the casting and sawed or broken off to be used as the test
ization established in the Decision on Principles for the
sample. If neither of these methods is convenient, microstruc-
Development of International Standards, Guides and Recom-
turaltestcoupons,suchasthoserecommendedbytheCastIron
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
1
This test method is under the jurisdiction of ASTM Committee A04 on Iron contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Castings and is the direct responsibility of Subcommittee A04.21 on Testing. Standards volume information, refer to the standard’s Document Summary page on
CurrenteditionapprovedJuly1,2017.PublishedJuly2017.Originallyapproved the ASTM website.
3
in 1941. Last previous edition approved in 2016 as A247–16a. DOI: 10.1520/ Available from ASTM International Headquarters. Order Adjunct No.
A0247-17. ADJA0247A. Original adjunct produced in 2010.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
A247 − 17
4
Research Committee (5R) of the American Foundry Society 7.7 TypeVI is the exploded nodule graphite form occasion-
shall be cast from metal representative of the castings poured. ally seen in ductile iron in conjunction with Types I and II.
7.8 Type VII is the flake graphite form usually seen in gray
6. Polishing
iron.
6.1 Grinding and
...