【国外标准】 Standard Specification for Hot Isostatically-Pressed Alloy Steel Flanges, Fittings, Valves, and Parts for High Temperature Service

This specification covers hot isostatically-pressed, powder metallurgy, alloy steel piping components such as flanges, fittings, valves, and similar parts for use in pressure systems and high-temperature services. Compacts shall be manufactured by placing a single powder blend into a can, evacuating the can, and sealing it. The entire assembly shall be heated and placed under sufficient pressure for a sufficient period of time to ensure that the final consolidated part meets the density requirements. The powder shall be prealloyed and made by a melting method such as vacuum induction melting followed by gas atomization. Alloy steels shall undergo annealing, liquid quenching, and tempering in accordance to heat treatment temperature and cooling media requirements. The steel both as a blend and as a part shall conform to the chemical composition requirements for carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, molybdenum, columbium, tantalum, and titanium. Density measurement, microstructural examination, and hydrostatic, tension, hardness, and fatigue tests shall be performed; wherein, the specimens shall conform to the specified structural integrity and mechanical property requirements such as porosity, microstructure, tensile strength, yield strength, elongation, reduction of area, and Brinell hardness.1.1 This specification covers hot isostatically-pressed, powder metallurgy, alloy steel piping components for use in pressure systems. Included are flanges, fittings, valves, and similar parts made to specified dimensions or to dimensional standards, such as in ASME Specification B16.5.1.2 Several grades of alloy steels are included in this specification.1.3 Supplementary requirements are provided for use when additional testing or inspection is desired. These shall apply only when specified individually by the purchaser in the order.1.4 This specification is expressed in both inch-pound units and in SI units. Unless the order specifies the applicable “M” specification designation (SI units), however, the material shall be furnished to inch-pound units.1.5 The values stated in either inch-pound units or SI units are to be regarded separately as the standard. Within the text, the SI units are shown in brackets. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other. Combining values from the two systems may result in nonconformance with the specification.1.6 The following safety hazards caveat pertains only to test methods portions, 8.1, 8.2, and 9.5 – 9.7 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 to determine the applicability of regulatory limitations prior to use.1.7 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.