Active Standard ASTM A988 / A988M | Developed by Subcommittee: A01.22
Book of Standards Volume: 01.01
Historical (view previous versions of standard)
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.
This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
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.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
A262 Practices for Detecting Susceptibility to Intergranular Attack in Austenitic Stainless Steels
A275/A275M Practice for Magnetic Particle Examination of Steel Forgings
A745/A745M Practice for Ultrasonic Examination of Austenitic Steel Forgings
A751 Test Methods, Practices, and Terminology for Chemical Analysis of Steel Products
A923 Test Methods for Detecting Detrimental Intermetallic Phase in Duplex Austenitic/Ferritic Stainless Steels
A961/A961M Specification for Common Requirements for Steel Flanges, Forged Fittings, Valves, and Parts for Piping Applications
B311 Test Method for Density of Powder Metallurgy (PM) Materials Containing Less Than Two Percent Porosity
E112 Test Methods for Determining Average Grain Size
E165 Practice for Liquid Penetrant Examination for General Industry
E340 Test Method for Macroetching Metals and Alloys
E606 Practice for Strain-Controlled Fatigue Testing
G48 Test Methods for Pitting and Crevice Corrosion Resistance of Stainless Steels and Related Alloys by Use of Ferric Chloride Solution
ASME Specifications and Boiler and Pressure Vessel CodesB16.5 Dimensional Standards for Steel Pipe Flanges and Flanged Fittings Available from American Society of Mechanical Engineers (ASME), ASME International Headquarters, Three Park Ave., New York, NY 10016-5990, http://www.asme.org.
ASME Specification IX Welding QualificationsSFA-5.11 Specification for Nickel and Nickel-Alloy Covered Welding Electrodes
ICS Number Code 49.025.10 (Steels)
UNSPSC Code 40170000(Pipe piping and pipe fittings)