ASTM A842-85(2009)

Standard Specification for Compacted Graphite Iron Castings

ABSTRACT
This specification deals with compacted graphite iron castings. These materials shall be examined metallographically for the acceptance graphite formation. The acceptable graphite formation in the microstructure of the test coupon or casting lug shall contain 80% minimum Type IV graphite. The iron shall conform to the requirements for tensile properties: tensile strength, yield strength, and elongation. Test bars and test coupons shall be cast in dried, baked, or chemically bonded molds consisting of an aggregate of silica sand with appropriate bonders and shall be subjected to the same thermal treatment as the castings they represent.
SCOPE
1.1 This specification covers castings made of compacted graphite iron, which is described as cast iron with the graphite in compacted (vermiform) shapes and essentially free of flake graphite.  
1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.3 No precise quantitative relationship can be stated between the properties of iron in the various locations of the same casting and those of a test bar cast from the same iron (see Appendix X1).

General Information

• Status: Historical
• Publication Date: 30-Apr-2009
• ICS: 77.080.10 - Irons
• ICS: 77.140.80 - Iron and steel castings
• Technical Committee: A04 - Iron Castings
• Drafting Committee: A04.02 - Malleable and Ductile Iron Castings

Relations

• Replaces: ASTM A842-85(2004) - Standard Specification for Compacted Graphite Iron Castings
• Effective Date: 01-May-2009
• Replaced By: ASTM A842-10 - Standard Specification for Compacted Graphite Iron Castings
• Effective Date: 01-Dec-2010
• Referred By: ASTM A834-95(2020) - Standard Specification for Common Requirements for Iron Castings for General Industrial Use
• Effective Date: 01-May-2009
• Referred By: ASTM A1095-15(2019) - Standard Specification for High-Silicon Molybdenum Ferritic Iron Castings
• Effective Date: 01-May-2009

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: A842 – 85 (Reapproved 2009)
Standard Specification for
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Compacted Graphite Iron Castings
This standard is issued under the fixed designation A842; 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.
TABLE 1 Tensile Requirements
1. Scope
A B
Grade Grade Grade Grade Grade
1.1 This specification covers castings made of compacted
250 300 350 400 450
graphite iron, which is described as cast iron with the graphite
Tensile strength, min,
in compacted (vermiform) shapes and essentially free of flake 250 300 350 400 450
MPa
graphite.
Yield strength, min,
175 210 245 280 315
MPa
1.2 The values stated in SI units are to be regarded as
Elongation in 50 mm,
3.0 1.5 1.0 1.0 1.0
standard. No other units of measurement are included in this
min, %
standard.
A
The 250 grade is a ferritic grade. Heat treatment to attain required mechanical
1.3 No precise quantitative relationship can be stated be-
properties and microstructure shall be the option of the manufacturer.
B
The 450 grade is a pearlitic grade usually produced without heat treatment
tweenthepropertiesofironinthevariouslocationsofthesame
with addition of certain alloys to promote pearlite as a major part of the matrix.
casting and those of a test bar cast from the same iron (see
Appendix X1).
2. Referenced Documents 3.1.4 If samples other than those identified in Section 9 are
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required,
2.1 ASTM Standards:
3.1.5 Certification if so designated by the purchaser, and
A247 Test Method for Evaluating the Microstructure of
3.1.6 Special preparation for delivery if required.
Graphite in Iron Castings
E8/E8M Test Methods for Tension Testing of Metallic
4. Chemical Composition
Materials
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4.1 It is the intent of this specification to subordinate
2.2 Federal Standard:
chemical composition to mechanical properties; however, any
Federal Standard No. 123 Marking for Shipment (Civil
chemical requirement may be specified by agreement between
Agencies)
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the manufacturer and the purchaser.
2.3 American National Standard:
MIL-STD-129 Marking for Shipment and Storage
5. Requirements
3. Ordering Information 5.1 Compacted graphite cast iron shall be examined metal-
lographically for the acceptable graphite formation.
3.1 Orders for material to this specification shall include the
5.2 Themetallographicexaminationshallbeperformedona
following information:
casting, a separately cast test coupon, as shown in Fig. 1 or on
3.1.1 ASTM designation and year of issue,
a test lug from a casting. The test coupon or casting lug shall
3.1.2 Grade of compacted graphite iron required as identi-
represent the last metal from the treated batch. The casting lug
fied in Table 1,
dimension and location will be agreed on by manufacturer and
3.1.3 Special properties if required, (see 4.1 and 10.1),
purchaser.
5.3 When castings are produced to this specification by
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This specification is under the jurisdiction of ASTM Committee A04 on Iron
treating the iron in the mold for graphite form control, the
Castings and is the direct responsibility of SubcommitteeA04.02 on Malleable and
manufacturer may use separately cast test coupons or cut test
Ductile Iron Castings.
specimens from castings to qualify conformance of the micro-
Current edition approved May 1, 2009. Published September 2009. Originally
approved in 1985. Last previous edition approved in 2004 as A842 - 85 (2004).
structure requirements. When separately cast test coupons are
DOI: 10.1520/A0842-85R09.
used, the test coupons shall have a chemical composition
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
representative of that in the castings, produced from that iron
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
poured, and having a cooling rate equivalent to that obtained
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
through use of test molds as shown in Figs. 1-4.The size of the
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AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
cast coupon representing the castings shall be the option of the
Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
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purchaser. In case no option is expressed, the manufacturer
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036. shall make the choice. When test specimens are to be taken
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A842 – 85 (2009)
FIG. 1 Test Coupon for Microscopical Examination of Compac
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