1、Designation: A 942 95 (Reapproved 2007)Standard Specification forCentrifugally Cast White Iron/Gray Iron Dual Metal Abrasion-Resistant Roll Shells1This standard is issued under the fixed designation A 942; the number immediately following the designation indicates the year oforiginal adoption or, in
2、 the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers double pour, centrifugally cast,abrasion-resistant roll
3、shells for general application. The outerlayer is white iron and the inner layer is gray iron. There shallbe no gradient of mottled iron between the white iron and thegray iron.1.2 The values stated in either inch-pound units or SI unitsare to be regarded separately as standard. Within the text, the
4、SI units are shown in brackets. The values stated in eachsystem are not exact equivalents; therefore, each system mustbe used independently of the other. Combining values from thetwo systems may result in nonconformance with this specifi-cation.2. Referenced Documents2.1 ASTM Standards:2A 48/A 48M S
5、pecification for Gray Iron CastingsE8 Test Methods for Tension Testing of Metallic MaterialsE10 Test Method for Brinell Hardness of Metallic Materi-als3. Classification3.1 The white iron portion of the casting shall be classifiedby type based upon Brinell Hardness.3.2 The gray iron portion of the ca
6、sting shall be classified byclass based upon tensile strength.4. Ordering Information4.1 Orders for material to this specification shall include thefollowing: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
7、 iron layer(8.1),4.1.4 Surface conditionas cast or machined,4.1.5 Type of white iron required for the outer layer of thecasting (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 requir
8、ed(Section 14).4.2 Additional requirements may be agreed upon betweenthe manufacturer and the purchaser.5. Materials and Manufacture5.1 Both the white and the gray irons may be melted by anysuitable melting process.5.2 The white iron portion of the casting shall be producedby chemistry rather than c
9、hilling.6. Chemical Composition6.1 A chemical analysis shall be performed by the manu-facturer on both the white and gray irons. The chemicalcompositions shall be controlled to obtain the required me-chanical properties.7. Mechanical Properties7.1 The white iron shall conform to the following requir
10、e-ments:Type I 450 to 500 HBType II 500 to 550 HBType III 550 to 600 HBType IV 600 to 650 HB7.2 The gray iron shall conform to the following require-ments:Tensile StrengthClass min, ksi min, (MPa)No. 20 20 (138)No. 25 25 (172)No. 30 30 (207)No. 35 35 (241)8. Other Requirements8.1 The thickness of th
11、e white iron layer shall be a mini-mum of12 in.1This specification is under the jurisdiction of ASTM Committee A04 on IronCastings and is the direct responsibility of SubcommitteeA04.01 on Grey and WhiteIron Castings.Current edition approved June 15, 2007. Published July 2007. Originallyapproved in
12、1995. Last previous edition approved in 2001 as A 942 95 (2001).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 websi
13、te.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.8.1.1 The thickness of the white iron layer shall be mea-sured on the roll face at each end and shall conform to thespecified thickness.9. Finish and Appearance9.1 All exterior surfa
14、ces shall be machined or ground priorto the rolls being placed into service.9.2 The manufacturer shall be responsible for providingcastings with adequate stock for final machining.9.3 Surfaces and corners of the machined castings shall befree from burrs and extremely sharp edges.9.4 Machined surface
15、s of the castings may be protected bythe application of a rust and corrosion 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 cropends removed from the casting.10.3 The tension
16、 test of the gray iron shall be performed onspecimens obtained from separately cast test bars poured inaccordance with Specification A 48/A 48M. Standard test barB shall be the size of the test bar poured.10.4 Chemical analysis shall be performed on samplesobtained during pouring of the iron.11. Tes
17、t Methods11.1 The hardness test shall be performed in accordancewith Test Method E10, using a 10-mm tungsten carbide balland 3000 kgf load. Test results shall be considered accurate upto 700 HB.11.2 The tension test shall be performed in accordance withTest Methods E8.12. Inspection12.1 All tests an
18、d inspections required by this specificationshall be performed by the manufacturer or other reliable sourcewhose services have been contracted by the manufacturer.Complete records of all tests and inspections shall be main-tained by the manufacturer, and shall be available for review bythe purchaser
19、.13. Certification13.1 When specified by the purchaser, the manufacturerscertification shall be furnished to the purchaser stating that thematerial was manufactured, sampled, tested, and inspected inaccordance with this specification. This certification shallinclude the results of all tests required
20、 by this specification andgive the thickness of the white iron supplied.14. Packaging and Package Marking14.1 When specified by the purchaser, the manufacturersname or identifying mark shall be stamped at one end in thegray iron portion of the casting. When further specified, thecasting identificati
21、on number shall be stamped at the castingend.14.2 Unless otherwise specified by the contract or purchaseorder, castings shall be packed in accordance with the manu-facturers commercial practice to ensure acceptance and safedelivery by the carrier.15. Keywords15.1 abrasion-resistant; cast iron; centr
22、ifugal casting; dualmetal; gray cast iron; 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 a
23、ny 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 andif not revised, either reapproved or withdrawn. Your comments are
24、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, which you may attend. If you feel that your comments have not recei
25、ved 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), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).A 942 95 (2007)2
