1、Designation: A 447/A447M 93 (Reapproved 2007)Standard Specification forSteel Castings, Chromium-Nickel-Iron Alloy (25-12 Class),for High-Temperature Service1This standard is issued under the fixed designation A 447/A447M; the number immediately following the designation indicates the yearof original
2、 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. Scope1.1 This specification covers iron-base, heat-resisting alloycastings o
3、f the 25 % chromium, 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. The purchaser should inform themanufacturer when the service temperatures are to exceed1800F 980C.1
4、.2 In the absence of significant proportions of elementsother than those prescribed in Section 4, the two types of alloyscovered 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
5、2000F 815and 1095C, and relatively high ductility at ordinary tempera-tures after aging for short periods at temperatures 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 sho
6、rt periods at temperatures between1350 and 1500F 730 and 815C.1.3 The values stated in either inch-pound units or SI unitsare to be regarded separately as standard. Within the text, theSI units are shown in brackets. The values stated in eachsystem are not exact equivalents; therefore, each system m
7、ustbe used independently of the other. Combining values from thetwo systems may result in nonconformance with the specifi-cation.2. Referenced Documents2.1 ASTM Standards:2A 781/A 781M Specification for Castings, Steel and Alloy,Common Requirements, for General Industrial UseA 800/A 800M Practice fo
8、r Steel Casting, Austenitic Alloy,Estimating Ferrite Content ThereofE8 Test Methods for Tension Testing of Metallic MaterialsE21 Test Methods for Elevated Temperature Tension Testsof Metallic Materials3. General Conditions for Delivery3.1 Material furnished to this specification shall conform tothe
9、requirements of Specification A 781/A 781M, includingany supplementary requirements that are indicated in thepurchase order. Failure to comply with the general require-ments of Specification A 781/A 781M constitutes nonconfor-mance with this specification. In case of conflict between therequirements
10、 of this specification and Specification A 781/A 781M, this specification shall prevail.4. Process4.1 The alloy for the castings shall be made by the electric-furnace process or by any other process approved by thepurchaser.5. Heat Treatment5.1 Except as otherwise agreed upon between the manufac-tur
11、er and the purchaser, the manufacturer shall not be requiredto heat treat the castings.6. Chemical Composition6.1 The castings shall conform to the requirements of Table1 as to chemical composition.7. Sampling7.1 Material for the tests specified in Sections 10, 12, and 13may be taken from separately
12、 cast test blocks of a form such asthat shown in Fig. 1, from another type of test block, from thecastings, or from coupons attached to the castings, as may beagreed upon between the manufacturer and the purchaser.7.2 Material for the magnetic permeability test specimen(Section 11) may be taken, pri
13、or to heat treatment, from thesame coupon as the specimen for the tension test after aging;from suitable specimens cast as parts of separately cast test1This specification is under the jurisdiction of ASTM Committee A01 on Steel,Stainless Steel and Related Alloys and is the direct responsibility of
14、SubcommitteeA01.18 on Castings.Current edition approved Nov. 1, 2007. Published December 2007. Originallyapproved in 1944. Redesignated as A 447 in 1961. Last previous edition approvedin 2003 as A 447/A 447M 93 (2003).2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact AS
15、TM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.blocks; or, by agreement bet
16、ween the manufacturer and thepurchaser, from castings representing the melt.7.3 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.7.4 In all cases, it shall b
17、e the manufacturers duty toprovide a sufficient number of samples for the specified tests.8. Number of Tests8.1 The purchaser shall specify not more than two tests. Thetests shall be selected from the following list, with therestriction that not more than one of the tension tests at hightemperature
18、(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, and8.1.4 Short-time high-temperature tension test.9. Retests9.1 Mechanical TestsIf any of the specimens first chosenfor any of the mechanical tests agreed upon fail to
19、 conform tothe specified requirements, an additional specimen from thesame melt may be tested. This additional specimen shallconform to the requirements prescribed for the test in question.9.2 Magnetic TestIf the magnetic permeability of thespecimen first tested does not conform to the requirementpr
20、escribed in 11.1, three additional specimens from the samemelt may be tested. At least two of these shall conform to theprescribed requirement.10. Tensile Properties After Aging10.1 The tensile properties of the material after aging shallconform to the following requirements:Type I Type IITensile st
21、rength, min, ksi MPa 80 550 80 550Elongation in 2 in. 50 mm, min, % 9 410.2 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 205C at rates notexceeding 200F 110C/h. The tension test specimens shallbe mac
22、hined from the heat-treated sample, and shall conformto the dimensions shown in Fig. 1 of Test Methods E8.10.3 The tension test shall be made in accordance with TestMethods E8. The speed of head of the testing machine shall beso adjusted that the rate of separation of the gage marks on thetest speci
23、men shall not exceed 0.1 in. 3 mm/min.11. Magnetic Permeability11.1 The magnetic permeability of the material shall con-form to the following requirements:Magnetic Permeability,maxType I 1.70Type II 1.05NOTE 1The magnetic permeability test gives a qualitative indicationof the ferrite content for all
24、oys falling within the range of chemicalcomposition specified in Section 6, excluding iron and other elements asmay be agreed upon. When special alloying elements are specified, theTABLE 1 Chemical RequirementsElement Composition, %NiA10.0014.00Cr 23.0028.00C 0.200.45N, max 0.20Mn, max 2.50Si, max 1
25、.75P, max 0.05S, max 0.05Fe and other elements as may be agreed upon between themanufacturer and the purchaserACommercial nickel usually carries a small amount of cobalt, and within theusual limits cobalt shall be counted as nickel.TABLE ContinuedMetric Equivalentsin. mm in. mm18 3.2 312 88.912 12.7
26、 4 101.61116 27.0 4116 103.2112 38.1 5 127.03 76.2 11 279.4NOTEPour through head; cover molten head with powdered charcoal,coke dust, etc., immediately after pouring, in order to keep head fluid aslong as possible.FIG. 1 Test Block for Tension Test SpecimenA 447/A447M 93 (2007)2magnetic permeability
27、 test is not recommended because its significancehas not yet been established for such alloys.11.2 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 ord
28、er to avoid errors thatmight arise from the presence of magnetizable oxides formedduring heating.11.3 Unless otherwise agreed upon between the purchaserand the manufacturer, the magnetic permeability shall bedetermined in accordance with Supplementary Requirement S1of Practice A 800/A 800M.NOTE 2Whe
29、re the test method used measures volume percent ferrite,conversion to magnetic permeability may be accomplished using thefollowing requirements:Volume, Ferrite, %,maxMagnetic Permeability,max181.051.7012. Stress-Rupture Test12.1 The following tensile stress shall be sustained for atleast 16 h withou
30、t rupturing the specimen:Tensile Stress,ksi MPaType IType II5 348 5512.2 The test specimen shall conform to the dimensionsshown in Fig. 1 of Test Methods E8.12.3 The specimen in the as-cast condition shall be mountedin the testing machine and held for1hat1600 6 10F 870 65.5C. The specimen shall then
31、 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.13. Short-Time, High-Temperature Tensile Properties13.1 The short-time, high-temperature tensile propertiesshall conform to the following requirements:Tensile S
32、trength, min, ksiMPaElongation in 2 in. 50 mm,min, %Type I as agreed upon betweenmanufacturer and purchaseras agreed upon betweenmanufacturer and purchaserType II 20 140 813.2 The test specimen shall conform to the dimensionsshown in Fig. 1 of Test Methods E8.13.3 The specimen in the as-cast conditi
33、on, 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 in the testing furnaceand held within this range of temperature for
34、 1 h, and the testload then applied.13.4 The test shall be made in accordance with PracticeE21except that the speed of head of the testing machine shallbe so adjusted that the rate of separation of the gage marks onthe test specimen shall not exceed 0.03 in. 0.8 mm/min.14. Defective Test Specimens14
35、.1 If any specimen shows defective machining or devel-ops flaws, it may be discarded and another specimen from thesame melt substituted.14.2 If any part of the fracture in any of the specimenssubjected to tension tests is more than34 in. 19.0 mm fromthe center of the gage length as indicated by gage
36、 marks placedon the specimen before testing, another specimen may besubstituted.15. Repair by Welding15.1 Weld repairs shall be inspected to the same qualitystandards as are used to inspect the castings.15.2 When heat treatment is specified, the castings shall beheat treated after welding.16. Keywor
37、ds16.1 ausenitic stainless steel; high temperature applications;stainless steel; steel castingsSUPPLEMENTARY REQUIREMENTSThe following supplementary requirements shall not be applied unless specified in the purchaseorder. A list of standardized supplementary requirements for use at the option of the
38、 purchaser isincluded in Specification A 781/A 781M. Those which are ordinarily considered suitable for use withthe specification are given below. Others enumerated in Specification A 781/A 781M may be usedwith this specification upon agreement between manufacturer and purchaser.S5. Examination of W
39、eld PreparationS8. MarkingS6. CertificationA 447/A447M 93 (2007)3APPENDIX(Nonmandatory Information)X1. BIBLIOGRAPHYX1.1 The following selected bibliography is appended foruse by those who may be interested in gaining some informa-tion about the complex behavior of metals under stress atelevated temp
40、eratures. The bibliography is by no meanscomplete, but will serve as an introduction to the subject.(1) Brophy, G. R., and Furman, D. E., “The CyclicTemperature Acceleration of Strain in Heat Resisting Alloys,”Transactions, TA-SEA, Am. Soc. Metals, Vol 30, No. 4,December 1942, pp. 11151138.(2) Fello
41、ws, J. A., Cook, E., and Avery, H. S., “Precision inCreep Testing,” Metals Technology, METYA,Am. Inst. Miningand Metallurgical Engrs. Technical Publication 1443, Vol 9,No. 5, August 1942, pp. 115.(3) Avery, H. S., Cook, E., and Fellows, J. A., “EngineeringProperties of Heat-Resistant Alloys,” Metals
42、 Technology ,METYA, Am. Inst. Mining and Metallurgical Engrs. TechnicalPublication 1480, Vol 9, No. 5, August 1942, pp. 122.(4) ASTM Recommended Practice E 22, for ConductingLong-Time High-Temperature Tension Tests of Metallic Ma-terials, 1958 Book of ASTM Standards, Part 3.(5) Gow, J. T., and Harde
43、r, O. E., “Balancing the Compo-sition of Cast 25 percent Chromium-12 percent Nickel TypeAlloys,” Transactions, TASEA, Am. Soc. Metals, Vol 30, No.4, December 1942, pp. 855935.(6) Gillett, H. W., “Some Things We Do not Know AboutCreep,” Henry Howe Memorial Lecture presented at a meetingof theAm. Inst
44、. Mining and Metallurgical Engrs.,August 1939.(7) Tapsell, H. J., “Creep of Metals,” Humphrey Milford,Oxford University Press, London (1931).(8) Symposium on Effect of Temperature on the Propertiesof Metals, Am. Soc. Mech. Engrs. and ASTM (1931). (Sym-posium issued as a separate publication, ASTM ST
45、P 12,ASTTA).(9) Compilation of Available High-Temperature CreepCharacteristics of Metals and Alloys, Joint Research Commit-tee on Effect of Temperature on the Properties of Metals (JointCommittee of Am. Soc. Mech. Engrs. and ASTM), March1938. ( ASTM STP 37, ASTTA).(10) Manjoine, M. J., “New Machines
46、 for Creep and Creep-Rupture Tests.”(Constant strain-rate tests) Transactions,TASEA, Am. Soc. Mech. Engrs., February 1945, pp. 111 and116.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this st
47、andard 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 five years a
48、ndif 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 committee,
49、 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, 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), 6
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