1、Designation: A447/A447M 11Standard Specification forSteel Castings, Chromium-Nickel-Iron Alloy (25-12 Class),for High-Temperature Service1This standard is issued under the fixed designation A447/A447M; the number immediately following the designation indicates the yearof original adoption or, in the
2、 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*1.1 This specification covers iron-base, heat-resisting alloycastings of the 25 % chromium
3、, 12 % nickel class, intended forstructural elements, containers, and supports in electric fur-naces, petroleum still tube supports, and for similar applica-tions up to 2000F 1095C.1.2 In the absence of significant proportions of elementsother than those prescribed in Section 5, the two types of all
4、oyscovered by this specification may in general be distinguished asfollows:1.2.1 Type IAlloys characterized by relatively low limit-ing creep stress at temperatures between 1500 and 2000F 815and 1095C, and relatively high ductility at ordinary tempera-tures after aging for short periods at temperatu
5、res between1300 and 1500F 705 and 815C.1.2.2 Type IIAlloys having relatively high limiting creepstress but which may develop low ductility at ordinary tem-peratures when aged for short periods at temperatures between1350 and 1500F 730 and 815C.1.3 The values stated in either SI units or inch-pound u
6、nitsare to be regarded separately as standard. The values stated ineach system may not be exact equivalents; therefore, eachsystem shall be used independently of the other. Combiningvalues from the two systems may result in non-conformancewith the standard.1.3.1 Within the text, the SI units are sho
7、wn in brackets.2. Referenced Documents2.1 ASTM Standards:2A781/A781M Specification for Castings, Steel and Alloy,Common Requirements, for General Industrial UseA800/A800M Practice for Steel Casting, Austenitic Alloy,Estimating Ferrite Content ThereofA957 Specification for Investment Castings, Steel
8、and Al-loy, Common Requirements, for General Industrial UseA1067 Specification for Test Coupons for Steel CastingsE8/E8M Test Methods for Tension Testing of MetallicMaterialsE21 Test Methods for Elevated Temperature Tension Testsof Metallic Materials3. General Conditions for Delivery3.1 Except for i
9、nvestment castings, material furnished tothis specification shall conform to the requirements of Speci-fication A781/A781M, including any supplementary require-ments that are indicated in the purchase order. Failure tocomply with the general requirements of Specification A781/A781M constitutes nonco
10、nformance with this specification. Incase of conflict between the requirements of this specificationand Specification A781/A781M, this specification shall pre-vail.3.2 Investment castings furnished to this specification shallconform to the requirements of Specification A957, includingany supplementa
11、ry requirements that are indicated in thepurchase order. Failure to comply with the general require-ments of Specification A957 constitutes nonconformance withthis specification. In the case of conflict between the require-ments of this specification and Specification A957, Specifica-tion A957 shall
12、 prevail.4. Ordering Information4.1 The inquiry and order should include or indicate thefollowing:4.1.1 A description of the casting by pattern number ordrawing (dimensional tolerances shall be included on thecasting drawing),4.1.2 Which standard (A447 or A447M) applies,1This specification is under
13、the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.18 on Castings.Current edition approved Oct. 1, 2011. Published November 2011. Originallyapproved in 1944. Redesignated as A447 in 1961. Last previous edition approv
14、ed in2010 as A447/A447M 10. DOI: 10.1520/A0447_A0447M-11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1*A
15、Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.1.3 The version of the alloy, i.e., Type I or Type II, to besupplied (Sections 1, 11, 12, 13, and 14).4.1.4 Options in th
16、e specification (Section 9), and4.1.5 The supplementary requirements desired including thestandards of acceptance.5. Process5.1 The alloy for the castings shall be made by the electric-furnace process or by any other process approved by thepurchaser.6. Heat Treatment6.1 Except as otherwise agreed up
17、on between the manufac-turer and the purchaser, the manufacturer shall not be requiredto heat treat the castings.7. Chemical Composition7.1 The castings shall conform to the requirements of Table1 as to chemical composition.8. Sampling8.1 Material for the tests specified in Sections 11, 13, and 14ma
18、y be taken from separately cast test blocks of a form such asthat shown in Fig. 2 of Specification A1067, from another typeof test block, from the castings, or from coupons attached to thecastings, as may be agreed upon between the manufacturer andthe purchaser.8.2 Material for the magnetic permeabi
19、lity test specimen(Section 12) may be taken, prior to heat treatment, from thesame coupon as the specimen for the tension test after aging;from suitable specimens cast as parts of separately cast testblocks; or, by agreement between the manufacturer and thepurchaser, from castings representing the m
20、elt.8.3 In the case of castings for unusual or severe service, thetest coupons shall be attached to the castings at convenientlocations as may be agreed upon between the manufacturer andthe purchaser.8.4 In all cases, it shall be the manufacturers duty toprovide a sufficient number of samples for th
21、e specified tests.9. Number of Tests9.1 The purchaser shall specify not more than two testsselected from the following list, with the restriction that notmore than one of the tension tests at high temperature (that is,9.1.3 or 9.1.4) may be required:9.1.1 Tension test after aging,9.1.2 Magnetic perm
22、eability test,9.1.3 Stress-rupture test, and9.1.4 Short-time high-temperature tension test.10. Retests10.1 Mechanical TestsIf any of the specimens first chosenfor any of the mechanical tests agreed upon fail to conform tothe specified requirements, an additional specimen from thesame melt may be tes
23、ted. This additional specimen shallconform to the requirements prescribed for the test in question.10.2 Magnetic TestIf the magnetic permeability of thespecimen first tested does not conform to the requirementprescribed in 12.1, three additional specimens from the samemelt may be tested. At least tw
24、o of these shall conform to theprescribed requirement.11. Tensile Properties After Aging11.1 The tensile properties of the material after aging shallconform to the following requirements:Type I Type IITensile strength, min, ksi MPa 80 550 80 550ElongationAin 2 in. (4D), min, % 9 4ElongationBin 5D, m
25、in, % 8.7 3.9AThese minima shall apply when tested according to Test Methods E8.BThese minima shall apply when tested according to Test Methods E8M.11.2 Samples from which the tension specimens are to betaken shall be heated for 24 h at 1400 6 25F 760 6 14Cand allowed to cool at least down to 400F 2
26、05C at rates notexceeding 200F 110C/h. The tension test specimens shallbe machined from the heat-treated sample, and shall conformto the dimensions shown in Fig. 8 of Test Methods E8/E8M.11.3 The tension test shall be made in accordance with TestMethods E8/E8M. The speed of the head of the testing m
27、achineshall be so adjusted that the rate of separation of the gagemarks on the test specimen shall not exceed 0.1 in./min 0.05mm/s.12. Magnetic Permeability12.1 The magnetic permeability of the material shall con-form to the following requirements:Magnetic Permeability,maxType I 1.70Type II 1.05NOTE
28、 1The magnetic permeability test gives a qualitative indicationof the ferrite content for alloys falling within the range of chemicalcomposition specified in Section 7, excluding iron and other elements asmay be agreed upon. When special alloying elements are specified, themagnetic permeability test
29、 is not recommended because its significancehas not yet been established for such alloys.12.2 The specimen shall be heated in air to 2000 6 25F1095 6 14C, held within this range for 24 h, and thenquenched in water. After quenching, all scale and superficialoxidized metal shall be removed in order to
30、 avoid errors thatmight arise from the presence of magnetizable oxides formedduring heating.12.3 Unless otherwise agreed upon between the purchaserand the manufacturer, the magnetic permeability shall bedetermined in accordance with Supplementary Requirement S1of Practice A800/A800M.TABLE 1 Chemical
31、 RequirementsElement Composition, %NiA10.0014.00Cr 23.0028.00C 0.200.45N, max 0.20Mn, max 2.50Si, max 1.75P, max 0.030S, max 0.030Fe and other elements as may be agreed upon between themanufacturer and the purchaserACommercial nickel usually carries a small amount of cobalt, and within theusual limi
32、ts cobalt shall be counted as nickel.A447/A447M 112NOTE 2Where the test method used measures volume percent ferrite,conversion to magnetic permeability may be accomplished using thefollowing requirements:Volume, Ferrite, %,maxMagnetic Permeability,max181.051.7013. Stress-Rupture Test13.1 The followi
33、ng tensile stress shall be sustained for atleast 16 h without rupturing the specimen:Tensile Stress,ksi MPaType IType II5 348 5513.2 The test specimen shall conform to the dimensionsshown in Fig. 8 of Test Methods E8/E8M.13.3 The specimen in the as-cast condition shall be mountedin the testing machi
34、ne and held for1hat1600 6 10F 870 65.5C. The specimen shall then be subjected to a steady tensileload while the temperature over the gage length is maintainedat 1600 6 10F 870 6 5.5C in an air atmosphere.14. Short-Time, High-Temperature Tensile Properties14.1 The short-time, high-temperature tensile
35、 propertiesshall conform to the following requirements:Tensile Strength, min, ksiMPaElongation in 2 in. 50 mm,min, %Type I as agreed upon betweenmanufacturer and purchaseras agreed upon betweenmanufacturer and purchaserType II 20 140 814.2 The test specimen shall conform to the dimensionsshown in Fi
36、g. 8 of Test Methods E8/E8M.14.3 The specimen in the as-cast condition, that is, withoutany heat treatment after cooling from the casting temperature,shall be subjected to a short-time tension test during which thetemperature shall be maintained at 1600 6 10F 870 65.5C. The specimen shall be mounted
37、 in the testing furnaceand held within this range of temperature for 1 h, and the testload then applied.14.4 The test shall be made in accordance with Practice E21except that the speed of head of the testing machine shall be soadjusted that the rate of separation of the gage marks on the testspecime
38、n shall not exceed 0.03 in. 0.8 mm/min.15. Defective Test Specimens15.1 If any specimen shows defective machining or devel-ops flaws, it may be discarded and another specimen from thesame melt substituted.15.2 If any part of the fracture in any of the specimenssubjected to tension tests is more than
39、34 in. 19.0 mm fromthe center of the gage length as indicated by gage marks placedon the specimen before testing, another specimen may besubstituted.16. Repair by Welding16.1 Weld repairs shall be inspected to the same qualitystandards as are used to inspect the castings.16.2 When heat treatment is
40、specified, the castings shall beheat treated after welding.17. Keywords17.1 austenitic stainless steel; high temperature applica-tions; stainless steel; steel castingsSUPPLEMENTARY REQUIREMENTSThe following supplementary requirements shall not be applied unless specified in the purchaseorder. A list
41、 of standardized supplementary requirements for use at the option of the purchaser isincluded in Specification A781/A781M. Those which are ordinarily considered suitable for use withthe specification are given below. Others enumerated in Specification A781/A781M may be used withthis specification up
42、on agreement between manufacturer and purchaser.S5. Examination of Weld PreparationS8. MarkingS6. CertificationA447/A447M 113SUMMARY OF CHANGESCommittee A01 has identified the location of selected changes to this standard since the last issue(A447/A447M 10) that may impact the use of this standard.
43、(Approved Oct. 1, 2011.)(1) Added citations to A957, A1067, and E8M where appli-cable,(2) Added Ordering Information,(3) Added minimum metric values for room temperatureelongation after aging,(4) Deleted Appendix X1.Committee A01 has identified the location of selected changes to this standard since
44、 the last issue(A447/A447M 93 (2007) that may impact the use of this standard. (Approved Oct. 1, 2010.)(1) Changed the limits for S and P in Table 1.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users
45、 of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every f
46、ive years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical
47、 committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken,
48、PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).A447/A447M 114
