【国外标准】 Standard Specification for Ferritic Ductile Iron Castings Suitable for Low-Temperature Service

This specification covers ductile iron castings suitable low temperature service. Castings shall be produced by casting or heat treatment and shall have essentially a ferritic structure that contains no massive carbides. The iron shall conform to the required chemical composition for carbon, silicon, phosphorus, magnesium, manganese, copper, nickel and chromium. The iron shall conform to the required tensile properties such as tensile strength, yield strength and elongation. Graphite contained in the microstructure shall be evaluated and the percentage of each graphite type shall be estimated. The surface of the casting shall be examined visually and shall be free from adhering sand, scale cracks, and hot tears.1.1 This specification covers ductile iron castings suitable for service at temperatures of −40 °F [–40 °C] and above.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.1.3 The following precautionary statement pertains only to the test methods portion, Section 11, of this specification: 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.1.4 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.