ASTM A748 A748M-1987(2003) Standard Specification for Statically Cast Chilled White Iron-Gray Iron Dual Metal Rolls for Pressure Vessel Use《压力容器用静铸冷硬白口铁 灰口铁双相金属轧卷标准规范》.pdf

1、Designation: A 748/A 748M 87 (Reapproved 2003)Standard Specification forStatically Cast Chilled White Iron-Gray Iron Dual Metal Rollsfor Pressure Vessel Use1This standard is issued under the fixed designation A 748/A 748M; the number immediately following the designation indicates the yearof origina

2、l 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 statically cast dual metal rollswith th

3、e outer layer of the roll body being chilled white iron ofdifferent chemical composition than the core and journals ofthe roll which is gray cast iron. The castings are suitable forpressure containing parts, the design strength of which is basedon the gray iron portion of the cylinder. The castings

4、aresuitable for service at temperatures up to 450F 232C.1.2 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 mustbe

5、used independent of the other. Combining values from thetwo systems may result in nonconformance with the specifi-cation.1.3 The following safety hazards statement pertains only tothe test method portion, 9, of this specification: This standarddoes not purport to address all of the safety concerns,

6、if any,associated with its use. It is the responsibility of the user of thisstandard to establish appropriate safety and health practicesand determine the applicability of regulatory limitations priorto use.2. Referenced Documents2.1 ASTM Standards:A 278 Specification for Gray Iron Castings for Pres

7、sure-Containing Parts for Temperatures Up to 650F (350C)2A 278M Specification for Gray Iron Castings for Pressure-Containing Parts for Temperatures Up to 345C Metric3A 667/A667M Specification for Centrifugally Cast DualMetal (Gray and White Cast Iron) Cylinders23. Ordering Information3.1 Orders for

8、material under this specification shall includethe following information:3.1.1 ASTM designation and year of issue,3.1.2 Dimensions of dual rolls,3.1.3 Class of gray iron in the roll core (see 4.2),3.1.4 Inspection requirements, if different (see 10.1),3.1.5 Certification, if required (see 11.1), and

9、3.1.6 Special position of marking information, if required(see 12.1).3.2 Any additional requirements not covered in this speci-fication are subject to agreement between the manufacturer andpurchaser.4. Materials and Manufacture4.1 The melting procedure shall be optional with thefoundry.4.2 The chill

10、ed white iron exterior of the roll body shall bemade to a minimum hardness of 60 Scleroscope “C”. The grayiron portion of the roll shall conform to the applicable class ofSpecifications A 278 and A 278M, as determined by designrequirements. The scope of this specification shall include Nos.20, 25, 3

11、0, and 35 of Specification A 278 Nos. 150, 175, 200,and 250 of Specification A 278M.4.3 The casting process shall be controlled to produce ametallurgical bond between the chilled white iron exterior andgray iron interior of the roll body.5. Test Requirements5.1 Tensile RequirementsTensile bars remov

12、ed from aprolongation at one end of the roll journal, in accordance withSpecifications A 278 and A 278M, shall have a tensile strengthnot less than 80 % of that specified by the applicable class ofSpecifications A 278 and A 278M.5.2 Thickness of Chilled White Iron:5.2.1 The thickness of the clear ch

13、illed white iron plus themottled iron at the roll face shall not be more than 30 % of thetotal finished wall thickness.1This specification is under the jurisdiction of ASTM Committee A04 on IronCastings and is the direct responsibility of Subcommittee A04.01 on Grey and WhiteIron Castings.Current ed

14、ition approved May 10, 2003. Published May 2003. Originallyapproved in 1977. Last previous edition approved in 1998 as A 748/A 748M 87(1998).2Annual Book of ASTM Standards, Vol 01.02.3Discontinued. Replaced by A 278/A 278M. See 2000 Annual Book of ASTMStandards, Vol 01.02.1Copyright ASTM Internation

15、al, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.2.2 The thickness of the chilled white iron exterior of theroll body shall be determined by measuring the chill depth atthe ends of the roll face.6. Finish6.1 All surfaces shall be machined or ground, or both,

16、priorto the rolls being placed into service.7. Number of Tests7.1 The number of tension tests shall be in accordance withSpecifications A 278 and A 278M.8. Specimen Preparation8.1 Test bars representing the gray iron portion of the rollshall be made from a prolongation at one end of the roll journal

17、in accordance with Specifications A 278 and A 278M. Tensiontest specimens machined from this prolongation shall conformto the dimensions shown for Specimen “C” in SpecificationsA 278 and A 278M.9. Test Method9.1 Tension test specimens shall fit the holders of the testingmachine in such a way that th

18、e load shall be axial. The use ofself-aligning shackles is suggested. After reaching a stressequivalent to 15 000 psi 100 MPa, the speed of the movinghead of the testing machine shall not exceed18 in. 3.2mm/min.10. Inspection10.1 The inspector representing the purchaser shall havefree entry at all t

19、imes, while work on the contract of thepurchaser is being performed, to all parts of the manufacturersworks that concern the manufacture of the material ordered.The manufacturer shall afford the inspector all reasonablefacilities to satisfy him that the material is being furnished inaccordance with

20、this specification. Unless otherwise specified,all tests and inspections shall be made at the place ofmanufacture prior to the shipment, and shall be so conducted asnot to interfere unnecessarily with the operation of the works.11. Acceptance and Certification11.1 Final acceptance of the casting sha

21、ll follow completemachining of the casting. Upon request of the purchaser andwhen so specified in the purchase order, a certification shall bemade on the basis of acceptance of the material. This shallconsist of a copy of the manufacturers test report or astatement by the supplier, accompanied by a

22、copy of the testresults, that the material has been sampled, tested, and in-spected in accordance with the provisions of this specification.Each certification so furnished shall be signed by an authorizedagent of the supplier or manufacturer.12. Product Marking12.1 Pressure-containing castings made

23、in accordance withthis specification shall have the name of the manufacturer orhis recognized trademark and the class of iron to which itconforms, cast or indelibly stamped on the surface indicated bythe purchaser or in such a position as not to injure theusefulness of the casting.ASTM International

24、 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 rights, and the riskof infringement of such rights, are entirely their ow

25、n 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 for revision of this standard or for additional standardsand should be ad

26、dressed 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 hearing you shouldmake your views known to the ASTM Committee on Standards, a

27、t 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 748/A 748M 87 (2003)2