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ASTM A942-95(R2018) pdf free download

ASTM A942-95(R2018) pdf free download.Standard Specification for Centrifugally Cast White Iron/Gray Iron Dual Metal Abrasion- Resistant Roll Shells
1. Scope
1.1 This specification covers double pour, centrifugally cast, abrasion-resistant roll shells for general application. The outer layer is white iron and the inner layer is gray iron. There shall be no gradient of mottled iron between the white iron and the gray iron. 1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard. 1.2.1 Within the text, the SI units are shown in brackets. 1.3 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Classification
3.1 The white iron portion of the casting shall be classified by type based upon Brinell hardness. 3.2 The gray iron portion ofthe casting shall be classified by class based upon tensile strength.
4. Ordering Information
4.1 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 ofwhite iron layer (8.1), 4.1.4 Surface condition—as cast 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), and 4.1.8 Special position of marking information, if required (Section 14). 4.2 Additional requirements may be agreed upon between the manufacturer and the purchaser.
5. Materials and Manufacture
5.1 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.
6. Chemical Composition
6.1 A chemical analysis shall be performed by the manu- facturer on both the white and gray irons. The chemical compositions shall be controlled to obtain the required me- chanical properties.
8. Other Requirements
8.1 The thickness of the white iron layer shall be a mini- mum of 1 ⁄ 2 in. 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 the specified thickness.
9. Finish and Appearance
9.1 All exterior surfaces shall be machined or ground prior to the rolls being placed into service. 9.2 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-preventive coating.
10. Sampling
10.1 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 separately cast test bars poured in accordance 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 Methods
11.1 The hardness test shall be performed in accordance with Test Method E10, using a 10-mm tungsten carbide ball and 3000-kgf load. Test results shall be considered accurate up to 700 HB.
12. Inspection
12.1 All tests and inspections required by this specification shall be performed by the manufacturer or other reliable source whose 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 by the purchaser.

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