1、Designation: A942 95 (Reapproved 2012)Standard Specification forCentrifugally Cast White Iron/Gray Iron Dual Metal Abrasion-Resistant Roll Shells1This standard is issued under the fixed designation A942; the number immediately following the designation indicates the year oforiginal adoption or, in t
2、he case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers double pour, centrifugally cast,abrasion-resistant roll she
3、lls 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, theSI
4、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:2A48/A48M Specif
5、ication for Gray Iron CastingsE8 Test Methods 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 classifiedby type based upon Brinell Hardness.3.2 The gray iron portion of the casting
6、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 iron
7、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 required(Sec
8、tion 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 chillin
9、g.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 require-ment
10、s: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 the whit
11、e 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 Subcommittee A04.01 on Grey and WhiteIron Castings.Current edition approved Oct. 1, 2012. Published November 2012. Originallyapproved in 19
12、95. Last previous edition approved in 2007 as A942 95 (2007).DOI: 10.1520/A0942-95R12.2For 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
13、 page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States18.1.1 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
14、.1 All exterior surfaces 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
15、.9.4 Machined surfaces 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 cas
16、ting.10.3 The tension test of the gray iron shall be performed onspecimens obtained from separately cast test bars poured inaccordance with Specification A48/A48M. Standard test bar Bshall be the size of the test bar poured.10.4 Chemical analysis shall be performed on samplesobtained during pouring
17、of the iron.11. Test 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. Inspecti
18、on12.1 All tests and 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 rev
19、iew bythe purchaser.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
20、 all tests required 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, thec
21、asting identification 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-resistan
22、t; cast iron; centrifugal 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 o
23、f 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 andif not revised, either reapproved or withdrawn.
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25、ents 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
26、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 95 (2012)2
