1、Designation: A 968/A 968M 96 (Reapproved 2001)Standard Specification forChromium, Chromium-Nickel, and Silicon Alloy Steel Barsand Shapes for Corrosion and Heat-Resisting Service1This standard is issued under the fixed designation A 968/A 968M; the number immediately following the designation indica
2、tes the yearof 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.1. Scope1.1 This specification covers hot- and cold-fin
3、ished alloysteel bars having a chromium content equal to or less than11.0 % including rounds, squares, hexagons, and hot-rolled orextruded shapes for use in corrosion and heat-resisting service.1.2 Some steels covered by this specification, especially thehigh silicon-containing steels, because of th
4、eir particular alloycontent and specialized properties, may require special care intheir fabrication and welding. Specific procedures are offundamental importance, and it is presupposed that all param-eters will be in accordance with approved test methods capableof producing the desired properties i
5、n the finished fabrication.1.3 The values stated in either inch-pound units or SI unitsare to be regarded separately as standard. The values stated ineach system are not exact equivalents; therefore, each systemmust be used independently of the other. Combining valuesfrom the two systems may result
6、in nonconformance with thisspecification.1.4 This specification and the applicable material specifica-tions are expressed in both inch-pound and SI units. However,unless the order specifies the applicable “M” specificationdesignation (SI units), the material shall be furnished ininch-pound units.2.
7、Referenced Documents2.1 ASTM Standards:A 484/A 484M Specification for General Requirements forStainless Steel Bars, Billets, and Forgings2A 751 Test Methods, Practices, and Terminology forChemical Analysis of Steel Products2E 527 Practice for Numbering Metals and Alloys (UNS)32.2 SAE Standard:SAE J
8、1086 Recommended Practice for Numbering Metalsand Alloys43. Ordering Information3.1 It is the responsibility of the purchaser to specify allrequirements that are necessary for material ordered under thisspecification. Such requirements may include, but are notlimited to, the following:3.1.1 Quantity
9、 (weight or number of pieces);3.1.2 Dimensions, including diameter or thickness (andwidth), shape or form, applicable prints or sketches, length, andso forth;3.1.3 Type or UNS designation (see Table 1);3.1.4 ASTM designation and edition year if other than latestedition;3.1.5 Heat-treated condition (
10、see Section 5);3.1.6 Finish (see Manufacture section of SpecificationA 484/A 484M);3.1.7 Supplementary requirements invoked for special ser-vices;3.1.8 Whether bars are to be rolled as bars or cut from stripor plate;3.1.9 Preparation for delivery (see Preparation for Deliverysection of Specification
11、 A 484/A 484M);3.1.10 Marking requirements (see Marking section ofSpecification A 484/A 484M);3.1.11 Surface preparation of shapes (see Manufacture sec-tion of Specification A 484/A 484M); and3.1.12 The intended use of the material, if the purchaserconsiders this useful information.NOTE 1A typical o
12、rdering description is as follows: 5000 lb 2000kg; 1.000-in. 25-mm round bar by 10 to 12 ft 3 to 4 m; UNS S70003;to Specification A XXX A XXX; annealed; centerless ground; plus anyoptional supplementary requirements; such as, for example, specialmarking instructions.1This specification is under the
13、jurisdiction of ASTM Committee A01 on Steel,Stainless Steel, and Related Alloys and is the direct responsibility of SubcommitteeA01.17 on Flat-Rolled and Wrought Stainless.Current edition approved Sept. 10, 1996. Published November 1996.2Annual Book of ASTM Standards, Vol 01.03.3Annual Book of ASTM
14、Standards, Vol 01.01.4Available from Society of Automotive Engineers, 400 Commonwealth Drive,Warrendale, PA 15096.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4. General Requirements4.1 In addition to the requirements of this spec
15、ification, allrequirements of the current editions of Specification A 484/A 484M shall apply. Failure to comply with the generalrequirements of Specification A 484/A 484M constitutes non-conformance with this specification.5. Heat Treatment5.1 UNS S70003 shall be furnished in the solution annealedco
16、ndition with subsequent light drawing and straighteningpermitted.6. Chemical Composition6.1 Chemical composition shall be reported to the pur-chaser, or his representative, and shall conform to the require-ments specified in Table 1.6.2 When a product analysis is performed or requested bythe purchas
17、er, the tolerance limits as described in SpecificationA 484/A 484M apply.6.3 Methods and practices relating to chemical analysisrequired by this specification shall be in accordance with TestMethods, Practices, and Terminology A 751.7. Mechanical Properties7.1 The material shall conform to the mecha
18、nical propertyrequirements specified in Table 2 for the grade ordered.At leastone room-temperature test shall be performed by the manufac-turer on a sample from at least one bar or shape from each lotof material.7.2 The yield strength shall be determined by the offset(0.2 %) method as prescribed in
19、Test Methods and DefinitionsA 370.7.3 Hardness measurements, when required, shall be madeat a location midway between the surface and the center of thecross section.8. Certification8.1 The material manufacturers certificate of compliancecertifying that the material was manufactured and tested inacco
20、rdance with this specification, together with a report of theresults required by this specification and the purchase order,shall be furnished at the time of shipment. The certificationshall be positively relatable to the lot of material represented.9. Product Marking9.1 Marking requirements shall be
21、 in accordance withSpecification A 484/A 484M.TABLE 1 Chemical Composition, %AGrade . . .UNS DesignationBS70003C 0.02Mn 2.0P 0.025S 0.010Si 6.5 to 8.0Ni 22.0 to 25.0Cr 8.0 to 11.0Mo 0.50AMaximum, unless range or minimum is indicated.BRefer to Practice E 527 and Recommended Practice SAE J 1086.TABLE
22、2 Mechanical Test RequirementsGrade UNS DesignationATensile Strength,min, ksi (MPa)0.2 % Yield Strength,min, ksi (MPa)Elongation in 2 in. or 50mm, min, %Hardness, maxBBrinell Rockwell B. . . S70003 78 (540) 35 (240) 40 217 95ARefer to Practice E 527 and Recommended Practice SAE J 1086.BEither Brinel
23、l or Rockwell B is permissible.A 968/A 968M 96 (2001)2ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent r
24、ights, 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 andif not revised, either reapproved or withdrawn. Your comments are invited either f
25、or 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, which you may attend. If you feel that your comments have not received a fair heari
26、ng 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), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).A 968/A 968M 96 (2001)3
