ASTM A436-84(2001)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: A 436 – 84 (Reapproved 2001)
Standard Specification for
Austenitic Gray Iron Castings
This standard is issued under the fixed designation A 436; 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.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope 3.1.5 Size and number of test bars required (see 11 through
8.4 and 12.1),
1.1 This specification covers austenitic gray iron castings
3.1.6 If special tests are required (see Section 7 and 9.1),
that are used primarily for their resistance to heat, corrosion,
3.1.7 If certification is required (see 14.1), and
and wear. Austenitic gray iron is characterized by uniformly
3.1.8 If different preparation for delivery requirements are
distributed graphite flakes, some carbides, and the presence of
needed (see 15.1).
sufficient alloy content to produce an austenitic structure.
1.2 The values stated in inch-pound units are to be regarded
4. Materials and Manufacture
as the standard.
4.1 Melting may be done in any furnace that produces
2. Referenced Documents castings meeting the chemical compositions and mechanical
properties outlined in this specification. These include cupolas,
2.1 ASTM Standards:
air furnaces, electric furnaces, crucible furnaces, and so forth.
E 30 Test Methods for Chemical Analysis of Steel, Cast
4.2 By agreement between the manufacturer and the pur-
Iron, Open-Hearth Iron, and Wrought Iron
chaser, the castings may be stress relieved by heating to and
E 59 PracticeforSamplingSteelandIronforDetermination
holding in the temperature range from 1150 to 1200°F (620 to
of Chemical Composition
650°C) for not less than 1 nor more than 2 h/in. of thickness in
E 94 Guide for Radiographic Examination
the thickest section. Heating and cooling shall be uniform and
E 165 Test Method for Liquid Penetrant Examination
shall be not more than 400°F (222°C)/h for castings less than
E 351 Test Methods for Chemical Analysis of Cast Iron—
1 in. in maximum thickness, nor more than 400°F/h divided by
All Types
the maximum section thickness in inches for thicker castings.
E 433 Reference Photographs for Liquid Penetrant Inspec-
During the cooling cycle, castings may be cooled in still air
tion
after the temperature has dropped to 600°F (315°C).
E 446 Reference Radiographs for Steel Castings Up to 2 in.
4.3 If the manufacturer can demonstrate that another treat-
(51 mm) in Thickness
ment provides satisfactory stress relief, it may be used by
3. Ordering Information
agreement between the manufacturer and the purchaser.
4.4 Whenever dimensional changes in high-temperature
3.1 Orders for material to this specification shall include the
service are a problem, by agreement between the manufacturer
following information:
and the purchaser, the castings may be stabilized by heating at
3.1.1 ASTM designation and date of issue,
1600°F (870°C) for 1 h/in. of section, for a minimum of 1 h.
3.1.2 Type of austenitic gray iron required (see 5.1),
Otherwise, the austenite that is supersaturated with respect to
3.1.3 Heat treatment required (see 4.2 through 4.5),
carbon may reject carbon during service and produce dimen-
3.1.4 If repair of castings is permitted (see 4.6),
sional changes.
4.5 By agreement between the manufacturer and the pur-
This specification is under the jurisdiction of ASTM Committee A04 on Iron
chaser, castings with chilled edges or excessive carbides may
CastingsandisthedirectresponsibilityofSubcommitteeA04.01onGrayandWhite
be annealed at 1750 to 1900°F (955 to 1040°C) for ⁄2to5h,
Iron Castings.
followed by uniform cooling, preferably in still air.
Current edition approved Jan. 27, 1984. Published May 1984. Originally
published as A 436–59 T. Last previous edition A 436–78. 4.6 Castings shall not be repaired by welding, plugging, or
Annual Book of ASTM Standards, Vol 03.05.
other methods without written permission from the purchaser.
Annual Book of ASTM Standards, Vol 03.03.
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A 436
5. Chemical Composition shape shown in Fig. 1. The size of bar cast to represent the
castingshallbeattheoptionofthepurchaser.Incasenooption
5.1 Many combinations of alloys can be used to obtain an
is expressed, the manufacturer shall make the choice. The test
austenitic gray iron. This specification includes only the six
bars shall be cast in open molds made of suitable core sand
types defined by the chemical composition limits specified in
with a minimum of 1 ⁄2in. (38 mm) of sand on all sides and
Table 1.
bottomofthe ⁄2-in.(13-mm)and1-in.(25-mm)sizes,and3in.
5.2 The chemical analysis for total carbon shall be made on
(76 mm) of sand for the 3-in. test bar.
chilled cast pencil-type specimens or from thin wafers approxi-
1 8.2 By agreement between the manufacturer and the pur-
mately ⁄32 in. (0.8 mm) thick cut from test coupons. Drillings
chaser, the 1-in. (25-mm) keel block shown in Fig. 2 may be
are not reliable because of the probable loss of graphite.
used. It shall be an open mold made of suitable core sand with
5.3 Drillings taken from test coupons, broken test speci-
aminimumof1 ⁄2 in.(38mm)ofsandonallsidesandbottom.
mens, or castings shall conform to the requirements for
8.3 It is recommended that test bars be poured immediately
chemical composition as given in Table 1. Sampling shall be
after the castings and from the same ladle of metal. If castings
conducted in accordance with Practice E 59 and chemical
are to be heat treated, test bars shall be included in the same
analysis in accordance with Test Methods E 351 and Test
furnace load.
Methods E 30. Test Methods E 30 should only be used for
8.4 By agreement between the manufacturer and the pur-
analyzing those elements for which specific coverage is not
chaser, tension test specimens may be cut directly from
provided for in Test Methods E 351.
centrifugal or other permanent mold castings. The location and
5.4 Spectrometric techniques may also be used for analysis,
orientation of such tension test specimens cut from castings
but should a dispute arise concerning chemical composition,
shall be specified as agreed upon by the manufacturer and the
chemical analyses determined by Test Methods E 351 and Test
purchaser.
Methods E 30 shall be used for referee analysis.
9. Workmanship, Finish, and Appearance
6. Mechanical Properties
6.1 Although these irons are not used primarily for their 9.1 The castings shall conform substantially to the dimen-
sions on the drawings furnished by the purchaser, or if no
strength,thetensilestrengthandBrinellhardnessareindicative
of the correct metallurgical structure. The six types shall drawing has been provided, to the dimensions predicated by
the pattern supplied by the purchaser.The castings shall be free
conform to the requirements given in Table 2.
of injurious defects. Surfaces of the castings shall be free of
7. Magnetic Property Requirements
burnt-on sand and shall be reasonably smooth. In other
7.1 A convenient shop test for differentiating the various respects, the castings shall conform to whatever points may be
types of austenitic gray iron is based on the fact t
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