ASTM A988/A988M-11 PDF

ABSTRACT This specification covers hot isostatically-pressed, powder metallurgy, stainless steel piping components such as flanges, fittings, valves, and similar parts, for use in pressure systems and temperature service applications. The specification includes several grades of martensitic, austenitic, age hardening, and austenitic-ferritic stainless steels. Compacts shall be manufactured by placing a single powder blend into a can, evacuating the can, and sealing it. The powder shall be prealloyed and made by a melting method (such as but not limited to air or vacuum induction melting, followed by gas atomization) to produce the specified chemical composition for carbon, manganese, phosphorus, sulfur, nickel, chromium, molybdenum, columbium, tantalum, copper, tungsten, and nitrogen. Other manufacturing requirements including compact homogeneity, microstructure, and can material removal are given. Heat treatment requirements, such as austenitizing or solutioning, cooling, quenching, tempering, and ageing, and structural integrity requirements, such as density, hydrostatic tests, and ultrasonic tests are detailed as well. Mechanical properties include tensile strength, yield strength, elongation, and hardness. Product analysis shall conform to the chemical requirements. SCOPE 1.1 This specification covers hot isostatically-pressed, powder metallurgy, stainless 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 martensitic, austenitic, age hardening, and austenitic-ferritic stainless 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 parentheses. 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 non-conformance with the standard. 1.6 The following safety hazards caveat pertains only to test methods portions 8.1, 8.2, 9.5-9.7, and Section 10 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 and health practices and determine the applicability of regulatory limitations prior to use.