ASTM A447/A447M-93(2007)
(Specification)Standard Specification for Steel Castings, Chromium-Nickel-Iron Alloy (25-12 Class), for High-Temperature Service
Standard Specification for Steel Castings, Chromium-Nickel-Iron Alloy (25-12 Class), for High-Temperature Service
ABSTRACT
This specification covers iron-base, heat-resisting alloy castings, intended for structural elements, containers, and supports in electric furnaces, petroleum still tube supports, and for similar applications. The alloys shall be electric-furnace processed and heat treated. The castings shall conform to the required chemical compositions of nickel, chromium, carbon, nitrogen, manganese, silicon, phosphorus, sulfur, and iron. The specimens shall undergo tension test after aging and short-time high-temperature tension test and shall conform to the required values of tensile strength and elongation. A stress-rupture test shall also be performed wherein the specimens shall conform to the required values of tensile stress. The specimen shall also conform to the required values of magnetic permeability.
SCOPE
1.1 This specification covers iron-base, heat-resisting alloy castings of the 25 % chromium, 12 % nickel class, intended for structural elements, containers, and supports in electric furnaces, petroleum still tube supports, and for similar applications up to 2000°F [1095°C]. The purchaser should inform the manufacturer when the service temperatures are to exceed 1800F [980C].
1.2 In the absence of significant proportions of elements other than those prescribed in Section 4 , the two types of alloys covered by this specification may in general be distinguished as follows:
1.2.1 Type I Alloys characterized by relatively low limiting creep stress at temperatures between 1500 and 2000°F [815 and 1095°C], and relatively high ductility at ordinary temperatures after aging for short periods at temperatures between 1300 and 1500°F [705 and 815°C].
1.2.2 Type II Alloys having relatively high limiting creep stress but which may develop low ductility at ordinary temperatures when aged for short periods at temperatures between 1350 and 1500°F [730 and 815°C].
1.3 The values stated in either inch-pound units or SI units are to be regarded separately as standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: A447/A447M – 93 (Reapproved 2007)
Standard Specification for
Steel Castings, Chromium-Nickel-Iron Alloy (25-12 Class),
for High-Temperature Service
This standard is issued under the fixed designationA447/A447M; 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.
1. Scope A781/A781M Specification for Castings, Steel and Alloy,
Common Requirements, for General Industrial Use
1.1 This specification covers iron-base, heat-resisting alloy
A800/A800M Practice for Steel Casting, Austenitic Alloy,
castings of the 25 % chromium, 12 % nickel class, intended for
Estimating Ferrite Content Thereof
structural elements, containers, and supports in electric fur-
E8 Test Methods for Tension Testing of Metallic Materials
naces, petroleum still tube supports, and for similar applica-
E21 Test Methods for Elevated Temperature Tension Tests
tions up to 2000°F [1095°C]. The purchaser should inform the
of Metallic Materials
manufacturer when the service temperatures are to exceed
1800°F [980°C].
3. General Conditions for Delivery
1.2 In the absence of significant proportions of elements
3.1 Material furnished to this specification shall conform to
otherthanthoseprescribedinSection4,thetwotypesofalloys
the requirements of SpecificationA781/A781M, including any
coveredbythisspecificationmayingeneralbedistinguishedas
supplementary requirements that are indicated in the purchase
follows:
order. Failure to comply with the general requirements of
1.2.1 Type I—Alloys characterized by relatively low limit-
Specification A781/A781M constitutes nonconformance with
ingcreepstressattemperaturesbetween1500and2000°F[815
this specification. In case of conflict between the requirements
and 1095°C], and relatively high ductility at ordinary tempera-
of this specification and Specification A781/A781M, this
tures after aging for short periods at temperatures between
specification shall prevail.
1300 and 1500°F [705 and 815°C].
1.2.2 Type II—Alloys having relatively high limiting creep
4. Process
stress but which may develop low ductility at ordinary tem-
4.1 The alloy for the castings shall be made by the electric-
peratures when aged for short periods at temperatures between
furnace process or by any other process approved by the
1350 and 1500°F [730 and 815°C].
purchaser.
1.3 The values stated in either inch-pound units or SI units
are to be regarded separately as standard. Within the text, the
5. Heat Treatment
SI units are shown in brackets. The values stated in each
5.1 Except as otherwise agreed upon between the manufac-
system are not exact equivalents; therefore, each system must
turer and the purchaser, the manufacturer shall not be required
be used independently of the other. Combining values from the
to heat treat the castings.
two systems may result in nonconformance with the specifi-
cation.
6. Chemical Composition
6.1 The castings shall conform to the requirements of Table
2. Referenced Documents
1 as to chemical composition.
2.1 ASTM Standards:
7. Sampling
7.1 MaterialforthetestsspecifiedinSections10,12,and13
This specification is under the jurisdiction of ASTM Committee A01 on Steel,
may be taken from separately cast test blocks of a form such as
Stainless Steel and Related Alloys and is the direct responsibility of Subcommittee
that shown in Fig. 1, from another type of test block, from the
A01.18 on Castings.
castings, or from coupons attached to the castings, as may be
Current edition approved Nov. 1, 2007. Published December 2007. Originally
agreed upon between the manufacturer and the purchaser.
approved in 1944. Redesignated asA447 in 1961. Last previous edition approved in
2003 as A447/A447M – 93 (2003). DOI: 10.1520/A0447_A0447M-93R07.
7.2 Material for the magnetic permeability test specimen
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
(Section 11) may be taken, prior to heat treatment, from the
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
same coupon as the specimen for the tension test after aging;
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. from suitable specimens cast as parts of separately cast test
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
A447/A447M – 93 (2007)
TABLE 1 Chemical Requirements
blocks; or, by agreement between the manufacturer and the
purchaser, from castings representing the melt.
Element Composition, %
7.3 In the case of castings for unusual or severe service, the
A
Ni 10.00–14.00
test coupons shall be attached to the castings at convenient
Cr 23.00–28.00
locationsasmaybeagreeduponbetweenthemanufacturerand
C 0.20–0.45
N, max 0.20
the purchaser.
Mn, max 2.50
7.4 In all cases, it shall be the manufacturer’s duty to
Si, max 1.75
provide a sufficient number of samples for the specified tests.
P, max 0.05
S, max 0.05
Fe and other elements as may be agreed upon between the
8. Number of Tests
manufacturer and the purchaser
8.1 The purchaser shall specify not more than two tests.The
A
Commercial nickel usually carries a small amount of cobalt, and within the
usual limits cobalt shall be counted as nickel. tests shall be selected from the following list, with the
restriction that not more than one of the tension tests at high
temperature (that is, 8.1.3 or 8.1.4) may be required:
8.1.1 Tension test after aging,
8.1.2 Magnetic permeability test,
8.1.3 Stress-rupture test, and
8.1.4 Short-time high-temperature tension test.
9. Retests
9.1 Mechanical Tests—If any of the specimens first chosen
for any of the mechanical tests agreed upon fail to conform to
the specified requirements, an additional specimen from the
same melt may be tested. This additional specimen shall
conform to the requirements prescribed for the test in question.
9.2 Magnetic Test—If the magnetic permeability of the
specimen first tested does not conform to the requirement
prescribed in 11.1, three additional specimens from the same
melt may be tested. At least two of these shall conform to the
prescribed requirement.
10. Tensile Properties After Aging
10.1 The tensile properties of the material after aging shall
conform to the following requirements:
Type I Type II
Tensile strength, min, ksi [MPa] 80 [550] 80 [550]
Elongation in 2 in. [50 mm], min, % 9 4
10.2 Samples from which the tension specimens are to be
taken shall be heated for 24 h at 1400 6 25°F [760 6 14°C]
and allowed to cool at least down to 400°F [205°C] at rates not
exceeding 200°F [110°C]/h. The tension test specimens shall
be machined from the heat-treated sample, and shall conform
TABLE Continued
to the dimensions shown in Fig. 1 of Test Methods E8.
Metric Equivalents
10.3 The tension test shall be made in accordance with Test
in. [mm] in. [mm]
Methods E8. The speed of head of the testing machine shall be
1 1
⁄8 [3.2] 3 ⁄2 [88.9]
so adjusted that the rate of separation of the gage marks on the
⁄2 [12.7] 4 [101.6]
1 1
1 ⁄16 [27.0] 4 ⁄16 [103.2] test specimen shall not exceed 0.1 in. [3 mm]/min.
1 ⁄2 [38.1] 5 [127.0]
3 [76.2] 11 [279.4]
11. Magnetic Permeability
11.1 The magnetic permeability of the material shall con-
NOTE—Pour through head; cover molten head with powdered charcoal,
coke dust, etc., immediately after pouring, in order to keep head fluid as
form to the following requirements:
long as possible.
Magnetic
...
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