ASTM A842-85(1997)

Standard Specification for Compacted Graphite Iron Castings

SCOPE
1.1 This specification covers castings made of compacted graphite iron, that 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 considered as the 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).

General Information

• Status: Historical
• Publication Date: 09-Apr-1997
• 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

• Replaced By: ASTM A842-85(2004) - Standard Specification for Compacted Graphite Iron Castings
• Effective Date: 01-May-2004
• Referred By: ASTM A834-95(2020) - Standard Specification for Common Requirements for Iron Castings for General Industrial Use
• Effective Date: 10-Apr-1997
• Referred By: ASTM A1095-15(2019) - Standard Specification for High-Silicon Molybdenum Ferritic Iron Castings
• Effective Date: 10-Apr-1997

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
An American National Standard
Designation: A 842 – 85 (Reapproved 1997)
Standard Specification for
Compacted Graphite Iron Castings
This standard is issued under the fixed designation A 842; 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, that is described as cast iron with the graphite in
Tensile strength, min,
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 considered as the
Elongation in 50 mm,
3.0 1.5 1.0 1.0 1.0
standard.
min, %
1.3 No precise quantitative relationship can be stated be-
A
The 250 grade is a ferritic grade. Heat treatment to attain required mechanical
tweenthepropertiesofironinthevariouslocationsofthesame
properties and microstructure shall be the option of the manufacturer.
B
The450gradeisapearliticgradeusuallyproducedwithoutheattreatmentwith
casting and those of a test bar cast from the same iron (see
addition of certain alloys to promote pearlite as a major part of the matrix.
Appendix X1).
2. Referenced Documents
4. Chemical Composition
2.1 ASTM Standards:
4.1 It is the intent of this specification to subordinate
A 247 Test Method for Evaluating the Microstructure of
chemical composition to mechanical properties; however, any
Graphite in Iron Castings
chemical requirement may be specified by agreement between
E8M Test Methods for Tension Testing of Metallic Mate-
the manufacturer and the purchaser.
rials (Metric)
2.2 Federal Standard:
5. Microstructure Requirements Microstructure Requirements
Fed. Std. No. 123 Marking for Shipment (Civil Agencies)
5.1 Compacted graphite cast iron shall be examined metal-
2.3 American National Standard:
lographically for the acceptable graphite formation.
MIL-STD-129 Marking for Shipment and Storage
5.2 Themetallographicexaminationshallbeperformedona
casting, a separately cast test coupon, as shown in Fig. 1 or on
3. Ordering Information
a test lug from a casting. The test coupon or casting lug shall
3.1 Orders for material to this specification shall include the
represent the last metal from the treated batch. The casting lug
following information:
dimension and location will be agreed on by manufacturer and
3.1.1 ASTM designation and year of issue,
purchaser.
3.1.2 Grade of compacted graphite iron required as identi-
5.3 When castings are produced to this specification by
fied in Table 1,
treating the iron in the mold for graphite form control, the
3.1.3 Special properties if required, (see 4.1 and 10.1),
manufacturer may use separately cast test coupons or cut test
3.1.4 If samples other than those identified in Section 9 are
specimens from castings to qualify conformance of the micro-
required,
structure requirements. When separately cast test coupons are
3.1.5 Certification if so designated by the purchaser, and
used, the test coupons shall have a chemical composition
3.1.6 Special preparation for delivery if required.
representative of that in the castings, produced from that iron
poured, and having a cooling rate equivalent to that obtained
This specification is under the jurisdiction of ASTM Committee A-4 on Iron through use of test molds as shown in Figs. 1-4.The size of the
Castings and is the direct responsibility of SubcommitteeA04.02 on Malleable and
cast coupon representing the castings shall be the option of the
Ductile Iron Castings.
purchaser. In case no option is expressed, the manufacturer
Current edition approved April 26, 1985. Published June 1985.
shall make the choice. When test specimens are to be taken
Annual Book of ASTM Standards, Vol 01.02.
Annual Book of ASTM Standards, Vol 03.01.
from a casting, the location shall be agreed on by the purchaser
AvailablefromStandardizationDocumentsOrderDesk,Bldg.4SectionD,700
and the manufacturer and documented on the casting drawing.
Robbins Ave., Philadelphia, PA 19111-5094, Attn: NPODS.
5 It is the manufacturer’s required responsibility to maintain
Available from American National Standards Institute, 11 West 42nd Street,
13th Floor, New York, NY 10036. adequate controls and documentation to assure the customer
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
A 842 – 85 (1997)
FIG. 1 Test Coupon for Microscopical Examination of Compacted Graphite Iron
NOTE—The length of the keel block shall be 6 in. (152 mm).
FIG. 2 Design and Dimensions for Mold for Separately Cast
Cylindrical Test Bars
that test specimen microstructures are representative of micro-
structure in the castings shipped.
Metric Equivalents
in. mm in. mm
5.4 The acceptable graphite formation in the microstructure
1 1
⁄2 12.7 1 ⁄2 38.1
of the test coupon or casting lug shall contain 80 % minimum
1 25.4 2 ⁄2 63.5
Type IV graphite (see Plate 1, Graphite Form Types of Test
FIG. 3 Keel Block
Method A 247A 247). The percentage graphite can be arrived
at by using the manual particle count, semiautomatic or
7. Cast Test Bars
automatic image analysis methods. Whichever method is used,
7.1 Test bars shall be separate castings poured from the
the procedure should be agreed on between the manufacturer
same iron as the castings they represent. The 30 mm diameter
and the purchaser.
cylindrical test bar shall be used as described in Table 2 and
5.5 Unless otherwise specified, the matrix microstructure of
shown in Fig. 2.
castingscoveredbythisspecificationshallbesubstantiallyfree
7.2 Test coupons may also be cast to the size and shape of
of primary cementite.
the keel block or modified keel block shown in Fig. 3 and Fig.
6. Tensile Requirements
4 respectively.
6.1 The iron as represented by the test specimens shall 7.3 Test bars and test coupons shall be cast in dried, baked,
conform to the requirements for tensile properties, as identified or chemically bonded molds consisting of an aggregate of
in Table 1. silica sand with the appropriate binders.All molds shall have a
6.2 The yield strength presented in Table 1 shall be deter- thickness of sand adjacent to the test piece equal to or greater
mined at 0.2 % offset by the offset method as described in Test than the thickness of the piece.
Methods E 8ME8M. Other methods may be used by mutual 7.4 The test bars or test coupons shall be poured from the
agreement between manufacturer and purchaser. same ladle or heat of iron as the castings they represent.
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Please contact ASTM International (www.astm.org) for the latest information.
A 842 – 85 (1997)
FIG. 4 Mold for Modified Keel Block
TABLE 2 Diameter and Length of Cast Test Bar
10.2 If after testing, a test specimen shows evidence of a
As Cast Diameter, mm Length, mm defect, the results of the test may be invalidated and another
Test Bar Nominal
made on a specimen from the same lot.
Minimum Maximum Minimum Maximum
10.3 If the results of a valid test fail to conform to the
B 30 29 31 150 230
requirements of this specification, two retests shall be made. If
either retest fails to meet the specification requirements, the
castings represented by thes
...