Реферат

This specification covers a group of common requirements that, unless covered by the individual product specification in another ASTM document, applies to steel forgings for general use. Materials shall be produced primarily by either electric-furnace, basic oxygen, vacuum-induction (VIM), or open-hearth melting process. The primary melting may incorporate separate degassing or refining and may be followed by secondary melting, using electro slag (ESR) or vacuum arc remelting (VAR). Steel shall be forged by any of these three classes based on forging temperature: cold-worked forging, hot-cold-worked forging, or hot-worked forging. After forging, specimens shall be allowed to cool prior to reheating for heat treatment. Details of heat and product analyses for the evaluation of chemical composition are thoroughly discussed. Tension and hardness tests shall be conducted to evaluate mechanical properties such as percentage of elongation and reduction of area. Repair welding shall not be allowed unless permitted by the product specification.

Область применения

1.1 This specification covers a group of common requirements that, unless otherwise specified in the individual product specification, shall apply to steel forgings under any of the following specifications issued by ASTM:

ASTM
DesignationTitle A 266/A 266M Carbon Steel Forgings for Pressure Vessel Components A 288 Carbon and Alloy Steel Forgings for Magnetic Retaining Rings for Turbine Generators A 289/A 289MAlloy Steel Forgings for Nonmagnetic Retaining Rings for Generators A 290/A 290MCarbon and Alloy Steel Forgings for Rings for Reduction Gears A 291/A 291MSteel Forgings, Carbon and Alloy, for Pinions, Gears, and Shafts for Reduction Gears A 336/A 336MAlloy Steel Forgings for Pressure and High-Temperature Parts A 372/A 372MCarbon and Alloy Steel Forgings for Thin-Walled Pressure Vessels A 427Wrought Alloy Steel Rolls for Cold and Hot Reduction A 469/A 469MVacuum-Treated Steel Forgings for Generator Rotors A 470/A 470MVacuum-Treated Carbon and Alloy Steel Forgings for Turbine Rotors and Shafts A 471Vacuum-Treated Alloy Steel Forgings for Turbine Rotor Disks and Wheels A 508/A 508MQuenched and Tempered Vacuum-Treated Carbon and Alloy Steel Forgings for Pressure Vessels A 521Steel, Closed-Impression Die Forgings for General Industrial Use A 541/A 541MQuenched and Tempered Carbon and Alloy Steel Forgings for Pressure Vessel Components A 579/A 579MSuperstrength Alloy Steel Forgings A 592/A 592M High-Strength Quenched and Tempered Low-Alloy Steel Forged Fittings and Parts for Pressure Vessels A 649/A 649MForged Steel Rolls Used for Corrugating Paper Machinery A 668/A 668MSteel Forgings, Carbon and Alloy, for General Industrial Use A 723/A 723MAlloy Steel Forgings for High-Strength Pressure Component Application A 765/A 765MCarbon Steel and Low-Alloy Steel Pressure-Vessel-Component Forgings with Mandatory Toughness Requirements A 768/A 768M Vacuum-Treated 12 % Chromium Alloy Steel Forgings for Turbine Rotors and Shafts A 837/A 837M Steel Forgings, Alloy, for Carburizing Applications A 859/A 859MAge-Hardening Alloy Steel Forgings for Pressure Vessel Components A 891 Precipitation Hardening Iron Base Superalloy Forgings for Turbine Rotor Disks and Wheels A 909Steel Forgings, Microalloy, for General Industrial Use A 940Vacuum Treated Steel Forgings, Alloy, Differentially Heat Treated, for Turbine Rotors A 965/A 965MSteel Forgings, Austenitic, for Pressure and High Temperature Parts A 983/A 983MSpecification for Continous Grain Flow Forged Carbon and Alloy Steel Crankshafts for Medium Speed Diesel Engines A 1021/A 1021MMartensitic Stainless Steel Forgings and Forging Stock for High-Temperature Service

1.2 In case of conflict in requirements, the requirements of the individual product specifications shall prevail over those of this specification.

1.3 The purchaser may specify additional requirements (see 4.2.3) that do not negate any of the provisions of either this specification or of the individual product specifications. The acceptance of any such additional requirements shall be dependent on negotiations with the supplier and must be included in the order.

1.4 If, by agreement, forgings are to be supplied in a partially completed condition, that is, all of the provisions of the product specification have not been filled, then the material marking (see Section 17) and certification (see Section 16) shall reflect the extent to which the product specification requirements have been met.

1.5 As noted in the Certification Section (16), the number and year date of this specification, as well as that of the product specification, are required to be included in the product certification.

1.6 When the SI version of a product specification is required by the purchase order, Specification A 788/A 788M shall be used.

1.7 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 non-conformance with the standard.

1.8 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.