1、Designation: A942 95 (Reapproved 2012)A942/A942M 95 (Reapproved 2012)1Standard Specification forCentrifugally Cast White Iron/Gray Iron Dual Metal Abrasion-Resistant Roll Shells1This standard is issued under the fixed designationA942;A942/A942M; the number immediately following the designation indic
2、ates theyear of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1 NOTEDesignation was converted to dual and editorial c
3、hanges were made throughout in November 2013.1. Scope1.1 This specification covers double pour, centrifugally cast, abrasion-resistant roll shells for general application. The outerlayer is white iron and the inner layer is gray iron. There shall be no gradient of mottled iron between the white iron
4、 and the grayiron.1.2 The values stated in either inch-poundSI units or SIinch-pound units are to be regarded separately as standard. Within thetext, the SI units are shown in brackets. The values stated in each system aremay not be exact equivalents; therefore, each systemmustshall be used independ
5、ently of the other. Combining values from the two systems may result in nonconformancenon-conformance with this specification.the standard.1.2.1 Within the text, the SI units are shown in brackets.2. Referenced Documents2.1 ASTM Standards:2A48/A48M Specification for Gray Iron CastingsE8 Test Methods
6、 for Tension Testing of Metallic MaterialsE10 Test Method for Brinell Hardness of Metallic Materials3. Classification3.1 The white iron portion of the casting shall be classified by type based upon Brinell Hardness.3.2 The gray iron portion of the casting shall be classified by class based upon tens
7、ile strength.4. Ordering Information4.1 Orders for material to this specification shall include the following:4.1.1 Specification title, designation, and year of issue,4.1.2 Quantity of castings required,4.1.3 Required dimensions and thickness of white iron layer (8.1),4.1.4 Surface conditionas cast
8、 or machined,4.1.5 Type of white iron required for the outer layer of the casting (7.1),4.1.6 Class of gray iron required for the inner layer (7.2),4.1.7 Certification, if required (Section 13), and4.1.8 Special position of marking information, if required (Section 14).4.2 Additional requirements ma
9、y be agreed upon between the manufacturer and the purchaser.5. Materials and Manufacture5.1 Both the white and the gray irons may be melted by any suitable melting process.5.2 The white iron portion of the casting shall be produced by chemistry rather than chilling.1 This specification is under the
10、jurisdiction of ASTM Committee A04 on Iron Castings and is the direct responsibility of Subcommittee A04.01 on Grey and White IronCastings.Current edition approved Oct. 1, 2012. Published November 2012. Originally approved in 1995. Last previous edition approved in 2007 as A942 95 (2007). DOI:10.152
11、0/A0942-95R12.10.1520/A0942-95R12E01.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an
12、ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In
13、 all cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States16. Chemical Composition6.1 A chemical analysis shall be performed by the
14、 manufacturer on both the white and gray irons. The chemical compositionsshall be controlled to obtain the required mechanical properties.7. Mechanical Properties7.1 The white iron shall conform to the following requirements:Type I 450 to 500 HBType II 500 to 550 HBType III 550 to 600 HBType IV 600
15、to 650 HB7.2 The gray iron shall conform to the following requirements:Tensile StrengthClass min, ksi min, (MPa)Class min, ksi min, MPaNo. 20 20 (138)No. 20 20 138No. 25 25 (172)No. 25 25 172No. 30 30 (207)No. 30 30 207No. 35 35 (241)No. 35 35 2418. Other Requirements8.1 The thickness of the white i
16、ron layer shall be a minimum of 12 in.8.1.1 The thickness of the white iron layer shall be measured on the roll face at each end and shall conform to the specifiedthickness.9. Finish and Appearance9.1 All exterior surfaces shall be machined or ground prior to the rolls being placed into service.9.2
17、The manufacturer shall be responsible for providing castings with adequate stock for final machining.9.3 Surfaces and corners of the machined castings shall be free from burrs and extremely sharp edges.9.4 Machined surfaces of the castings may be protected by the application of a rust and corrosion
18、preventive coating.10. Sampling10.1 Each casting shall be tested for chemical composition, hardness, and tensile strength.10.2 The white iron hardness shall be determined on crop ends removed from the casting.10.3 The tension test of the gray iron shall be performed on specimens obtained from separa
19、tely cast test bars poured inaccordance with Specification A48/A48M. Standard test bar B shall be the size of the test bar poured.10.4 Chemical analysis shall be performed on samples obtained during pouring of the iron.11. Test Methods11.1 The hardness test shall be performed in accordance with Test
20、 Method E10, using a 10-mm tungsten carbide ball and 3000kgf load. Test results shall be considered accurate up to 700 HB.11.2 The tension test shall be performed in accordance with Test Methods E8.12. Inspection12.1 All tests and inspections required by this specification shall be performed by the
21、manufacturer or other reliable sourcewhose services have been contracted by the manufacturer. Complete records of all tests and inspections shall be maintained by themanufacturer, and shall be available for review by the purchaser.13. Certification13.1 When specified by the purchaser, the manufactur
22、ers certification shall be furnished to the purchaser stating that thematerial was manufactured, sampled, tested, and inspected in accordance with this specification. This certification shall include theresults of all tests required by this specification and give the thickness of the white iron supp
23、lied.14. Packaging and Package Marking14.1 When specified by the purchaser, the manufacturers name or identifying mark shall be stamped at one end in the gray ironportion of the casting. When further specified, the casting identification number shall be stamped at the casting end.A942/A942M 95 (2012
24、)1214.2 Unless otherwise specified by the contract or purchase order, castings shall be packed in accordance with themanufacturers commercial practice to ensure acceptance and safe delivery by the carrier.15. Keywords15.1 abrasion-resistant; cast iron; centrifugal casting; dual metal; gray cast iron
25、; roll shell; white cast ironASTM 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 rights, and the riskof inf
26、ringement 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 for revision of this standa
27、rd 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 hearing you shouldmake your vie
28、ws 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). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).A942/A942M 95 (2012)13
