ASTM A436-84(1997)e1

NOTICE: This standard has either been superseded and replaced by a new version or
discontinued. Contact ASTM International (www.astm.org) for the latest information.
e1
Designation: A 436 – 84 (Reapproved 1997)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
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.
e NOTE—Keywords were added editorially in September 1997.
1. Scope 3.1.8 If different preparation for delivery requirements are
needed (see 15.1).
1.1 This specification covers austenitic gray iron castings
that are used primarily for their resistance to heat, corrosion,
4. Materials and Manufacture
and wear. Austenitic gray iron is characterized by uniformly
4.1 Melting may be done in any furnace that produces
distributed graphite flakes, some carbides, and the presence of
castings meeting the chemical compositions and mechanical
sufficient alloy content to produce an austenitic structure.
properties outlined in this specification. These include cupolas,
1.2 The values stated in inch-pound units are to be regarded
air furnaces, electric furnaces, crucible furnaces, etc.
as the standard.
4.2 By agreement between the manufacturer and the pur-
chaser, the castings may be stress relieved by heating to and
2. Referenced Documents
holding in the temperature range from 1150 to 1200°F (620 to
2.1 ASTM Standards:
650°C) for not less than 1 nor more than 2 h/in. of thickness in
E 30 Test Methods for Chemical Analysis of Steel, Cast
2 the thickest section. Heating and cooling shall be uniform and
Iron, Open-Hearth Iron, and Wrought Iron
shall be not more than 400°F (222°C)/h for castings less than
E 59 Practice for Sampling Steel and Iron for Determination
1 in. in maximum thickness, nor more than 400°F/h divided by
of Chemical Composition
3 the maximum section thickness in inches for thicker castings.
E 94 Guide for Radiographic Testing
During the cooling cycle, castings may be cooled in still air
E 165 Test Method for Liquid Penetrant Examination
after the temperature has dropped to 600°F (315°C).
E 351 Test Methods for Chemical Analysis of Cast Iron—
4.3 If the manufacturer can demonstrate that another treat-
All Types
ment provides satisfactory stress relief, it may be used by
E 433 Reference Photographs for Liquid Penetrant Inspec-
agreement between the manufacturer and the purchaser.
tion
4.4 Whenever dimensional changes in high-temperature
E 446 Reference Radiographs for Steel Castings Up to 2 in.
service are a problem, by agreement between the manufacturer
(51 mm) in Thickness
and the purchaser, the castings may be stabilized by heating at
1600°F (870°C) for 1 h/in. of section, for a minimum of 1 h.
3. Ordering Information
Otherwise, the austenite that is supersaturated with respect to
3.1 Orders for material to this specification shall include the
carbon may reject carbon during service and produce dimen-
following information:
sional changes.
3.1.1 ASTM designation and date of issue,
4.5 By agreement between the manufacturer and the pur-
3.1.2 Type of austenitic gray iron required (see 5.1),
chaser, castings with chilled edges or excessive carbides may
3.1.3 Heat treatment required (see 4.2 through 4.5),
be annealed at 1750 to 1900°F (955 to 1040°C) for ⁄2to5h,
3.1.4 If repair of castings is permitted (see 4.6),
followed by uniform cooling, preferably in still air.
3.1.5 Size and number of test bars required (see 11 through
4.6 Castings shall not be repaired by welding, plugging, or
8.4 and 12.1),
other methods without written permission from the purchaser.
3.1.6 If special tests are required (see Section 7 and 9.1),
3.1.7 If certification is required (see 14.1), and
5. Chemical Composition
5.1 Many combinations of alloys can be used to obtain an
1 austenitic gray iron. This specification includes only the six
This specification is under the jurisdiction of ASTM Committee A-4 on Iron
types defined by the chemical composition limits specified in
Castings and is the direct responsibility of Subcommittee A04.01 on Gray Iron
Castings.
Table 1.
Current edition approved Jan. 27, 1984. Published May 1984. Originally
5.2 The chemical analysis for total carbon shall be made on
published as A 436–59 T. Last previous edition A 436–78.
chilled cast pencil-type specimens or from thin wafers approxi-
Annual Book of ASTM Standards, Vol 03.05.
Annual Book of ASTM Standards, Vol 03.03. mately ⁄32 in. (0.8 mm) thick cut from test coupons. Drillings
A 436
TABLE 1 Chemical Requirements
Element Composition, %
Type 1 Type 1b Type 2 Type 2b Type 3 Type 4 Type 5 Type 6
Carbon, total, max 3.00 3.00 3.00 3.00 2.60 2.60 2.40 3.00
Silicon 1.00–2.80 1.00–2.80 1.00–2.80 1.00–2.80 1.00–2.00 5.00–6.00 1.00–2.00 1.50–2.50
Manganese 0.5–1.5 0.5–1.5 0.5–1.5 0.5–1.5 0.5–1.5 0.5–1.5 0.5–1.5 0.5–1.5
Nickel 13.50–17.50 13.50–17.50 18.00–22.00 18.00–22.00 28.00–32.00 29.00–32.00 34.00–36.00 18.00–22.00
Copper 5.50–7.50 5.50–7.50 0.50 max 0.50 max 0.50 max 0.50 max 0.50 max 3.50–5.50
A
Chromium 1.5–2.5 2.50–3.50 1.5–2.5 3.00–6.00 2.50–3.50 4.50–5.50 0.10 max 1.00–2.00
Sulfur, max 0.12 0.12 0.12 0.12 0.12 0.12 0.12 0.12
Molybdenum, max . . . . . . . 1.00
A
Where some machining is required, the 3.00–4.00 % chromium range is recommended.
are not reliable because of the probable loss of graphite. is expressed, the manufacturer shall make the choice. The test
5.3 Drillings taken from test coupons, broken test speci- bars shall be cast in open molds made of suitable core sand
mens, or castings shall conform to the requirements for with a minimum of 1 ⁄2 in. (38 mm) of sand on all sides and
chemical composition as given in Table 1. Sampling shall be bottom of the ⁄2-in. (13-mm) and 1-in. (25-mm) sizes, and 3 in.
conducted in accordance with Practice E 59 and chemical (76 mm) of sand for the 3-in. test bar.
analysis in accordance with Test Methods E 351 and Methods 8.2 By agreement between the manufacturer and the pur-
E 30. Test Methods E 30 should only be used for analyzing chaser, the 1-in. (25-mm) keel block shown in Fig. 2 may be
those elements for which specific coverage is not provided for used. It shall be an open mold made of suitable core sand with
in Test Methods E 351. a minimum of 1 ⁄2 in. (38 mm) of sand on all sides and bottom.
5.4 Spectrometric techniques may also be used for analysis, 8.3 It is recommended that test bars be poured immediately
but should a dispute arise concerning chemical composition, after the castings and from the same ladle of metal. If castings
chemical analyses determined by Test Methods E 351 and are to be heat treated, test bars shall be included in the same
Methods E 30 shall be used for referee analysis. furnace load.
8.4 By agreement between the manufacturer and the pur-
6. Mechanical Properties
chaser, tension test specimens may be cut directly from
6.1 Although these irons are not used primarily for their
centrifugal or other permanent mold castings. The location and
streng
...