ASTM A602-94(2022)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:A602 −94 (Reapproved 2022)
Standard Specification for
Automotive Malleable Iron Castings
This standard is issued under the fixed designation A602; 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 hardness readings. The area or areas on the casting where
hardness is to be checked shall be established by agreement
1.1 This specification covers castings of ferritic, pearlitic,
between supplier and purchaser and shown on the drawing.
tempered pearlitic, and tempered martensitic grades of mal-
leable iron used in the products of the automotive and allied
5. Microstructure Requirements
industries. Castings shall be heat treated to meet this specifi-
cation.
5.1 Grade M3210 Ferritic Malleable Iron:
5.1.1 The microstructure of Grade M3210 malleable iron
1.2 The values stated in inch-pound units are to be regarded
shall consist of temper-carbon nodules distributed in a matrix
as standard. The values given in parentheses are mathematical
of ferrite.
conversions to SI units that are provided for information only
5.1.2 Because of reaction with the annealing furnace
and are not considered standard.
atmosphere,somedepletionofcarbonandsiliconoccursatthe
1.3 This international standard was developed in accor-
surface of the castings. This usually results in a rim which can
dance with internationally recognized principles on standard-
consist of coarse lamellar pearlite underlying a graphite-free
ization established in the Decision on Principles for the
ferritic surface layer. If the pearlite layer is excessive, it can
Development of International Standards, Guides and Recom-
result in poor machinability. The rim, therefore, shall not
mendations issued by the World Trade Organization Technical
exceed a depth greater than 0.050 in. (1.27 mm) as measured
Barriers to Trade (TBT) Committee.
from the casting surface.
5.1.3 The area below the rim can contain some pearlite;
2. Referenced Documents
however, it shall not exceed the amount shown in Fig. 1.
2.1 ASTM Standards:
5.2 Grades M4504, M5003, M7002, and M8501:
E10Test Method for Brinell Hardness of Metallic Materials
5.2.1 The microstructure of these other grades of malleable
iron shall consist of temper-carbon nodules distributed in a
3. Grades
matrix of ferrite and lamellar pearlite or tempered pearlite in
3.1 The specified grades with required hardness range and
air-quenchedcastingsoramatrixoftemperedmartensiteinthe
final heat treatment are shown in Table 1.
case of liquid-quenched castings.
3.2 The foundry may also produce Grades M4504 and
5.2.2 Because of reaction with the annealing furnace
M5003byliquidquenchingandtemperingoralloying,orboth.
atmosphere,somedepletionofcarbonandsiliconoccursatthe
surface of the castings. This usually results in a rim which can
4. Hardness
consist of a graphite-free layer sometimes containing more or
4.1 The foundry shall exercise the necessary controls and
less combined carbon than the underlying material.
inspection procedures to ensure compliance with the specified
5.3 All grades shall be free of primary graphite.
hardnessrange.Hardnessreadingsshallbetakeninaccordance
5.4 All grades shall not exceed 2% spheroidal primary
with Test Method E10 after sufficient material has been
carbides in the microstructure.
removed from the casting surface to ensure representative
5.5 The maximum surface ferrite layer and denodularized
zone shall be measured after polishing, etching in nital, and
This specification is under the jurisdiction of ASTM Committee A04 on Iron
viewing at 100×.
Castings and is the direct responsibility of Subcommittee A04.02 on Malleable and
Ductile Iron Castings.
Current edition approved Oct. 1, 2022. Published October 2022. Originally
6. Quality Assurance
approved in 1970. Last previous edition approved in 2018 as A602–94(2018).
DOI: 10.1520/A0602-94R22.
6.1 Sampling plans are a matter of agreement between
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
supplier and purchaser. The supplier shall employ adequate
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
equipment and controls to ensure that parts conform to the
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. agreed-upon requirements.
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A602−94 (2022)
TABLE 1 Grades of Malleable Iron
Casting Hardness
Grade Heat Treatment
Range
M3210 156 HB max annealed
A
4.8 BID min
M4504 163–217 HB air quenched and tempered
A
4.7–4.1 BID
M5003 187–241 HB air quenched and tempered
A
4.4–3.9 BID
M5503 187–241 HB liquid quenched and tempered
A
4.4–3.9 BID
M7002 229–269 HB liquid quenched and tempered
A
4.0–3.7 BID
M8501 269–302 HB liquid quenched and tempered
A
3.7–3.5 BID
A
Brinellimpressiondiameter(BID)isthediameterinmillimetresoftheimpression
of a 10 mm ball at 3000 kg load.
FIG. 1 Reference Photomicrograph Showing Allowable Pearlite
7. General
in Grade M3210 Iron (100×; 2% Nital Etch)
7.1 Castings furnished to this specification shall be repre-
7.3 Additional casting requirements may be agreed upon
sentative of good foundry practice and shall conform to
between the purchaser and supplier. These should appear as
dimensions and tolerances specified on the casting drawing.
additional product requirements on the casting drawing.
7.2 Minor imperfections usually not associated with the
8. Keywords
structural function may occur in castings. These imperfections
often are repairable; however, repairs shall be made only in 8.1 casting; ferrite; malleable iron; mechanical properties;
areasallowedbythepurchaserandonlybyapprovedmethods. pearlite;tempercarbonnodules;tensilestrength;yieldstrength
APPENDIX
(Nonmandatory Information)
X1. MATERIAL DESCRIPTION OF MALLEABLE IRON
X1.1 Definition and Classification X1.3 Microstructure
X1.1.1 malleable iron—a cast iron in which the graphite is
X1.3.1 The microstructure of malleable iron consists of a
present as temper-carbon nodules instead of flakes, as in gray
matrix of ferrite, pearlite, tempered pearlite, or tempered
iron, or small spherulites, as in ductile iron.
m
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