【国外标准】 Standard Specification for Compacted Graphite Iron Castings

This specification deals with compacted graphite iron castings. These materials shall be examined metallographically for the acceptance graphite formation. The acceptable graphite formation in the microstructure of the test coupon or casting lug shall contain 80% minimum Type IV graphite. The iron shall conform to the requirements for tensile properties: tensile strength, yield strength, and elongation. Test bars and test coupons shall be cast in dried, baked, or chemically bonded molds consisting of an aggregate of silica sand with appropriate bonders and shall be subjected to the same thermal treatment as the castings they represent.1.1 This specification covers castings made of compacted graphite iron, which is described as cast iron with the graphite in compacted (vermiform) shapes and essentially free of flake graphite in the bulk of the casting.1.2 No precise quantitative relationship can be stated between the properties of iron in the various locations of the same casting and those of a test bar cast from the same iron (see Appendix X1).1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3.1 Exception—The inch-pound units in Figs. 1-3 are standard. SI units are added for information only.NOTE 1: The length of the keel block shall be 6 in. (152 mm).FIG. 3 Mold for Modified Keel Block1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.