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ASTM A484M-1998 Standard Specification for General Requirements for Stainless Steel and Heat-Resistant Steel Bars, Billets, and Forgings
This ASTM A484M-1998 standard covers general requirements for stainless steel and heat-resistant steel bars, billets and forgings. The requirements for material, sizing, and tolerances are prescribed. For shapes, hollows, thread lengths, and other dimensions, see that published material specification covering the desired material.
This standard provides the chemical and mechanical requirements for stainless and heat-resistant steel bars in a metric form. Stainless materials in the range of 17-4PH to billet are covered, as well as heat-resistant steel and nickel-base alloy forgings.
Materials: These stainless and heat-resistant steel bars, billets and forgings are designated respectively in the categories of martensitic stainless, ferritic stainless, austenitic stainless and precipitation-hardening, and heat-resistant steel.
The types of steel covered in this standard are bar, billet and forging. Bars, with or without further cold-working, may be supplied as applicable to ASTM A511 or to ASTM A479/A479M, if so desired, for further processing such as cold forming, machining, and welding. Forgings may be supplied in the normalizing and annealed condition if so desired for further cold-working.
Size Tolerances: Forbars and billets, the size tolerances for ASTM A484/A484M depend on the type of material being supplied, with grouped and fractional designations as follows:
• Group I – low carbon stainless (13Cr)
• Group II – austenitic stainless
• Group III – precipitation hardening stainless
• Group IV – ferritic stainless
• Group V – high-alloy heat-resistant steel
Additional tolerance limits are listed in the standard for various sizes such as high-speed steel and Martensitic stainless grades and for manufacture by certain processes such as cogging and cold-heading.
For forgings, the size tolerances are covered in ASTM A743/A743M and A747/A747M and detailed in Tables 1 and 2 of this standard.
Chemical Requirements: Chemical composition requirements for the various grades of stainless steel and heat-resistant steel are covered in the ASTM A484M standard. Alloy content must conform to the prescribed limits for the specific grade in order for the material to qualify for the mechanical requirements set out in the standard.
Mechanical Requirements: The ASTM A484M standard is primarily for chemical composition requirements, but does contain mechanical property requirements. The basic strength levels for martensitic and ferritic materials as well as austenitic and precipitation hardening materials are set out in the standard, based on diameter or thickness. For example, the minimum ultimate tensile strength is set out as follows:
• Martensitic and ferritic grades 800 MPa (116 ksi)
• Austenitic and precipitation hardening grades 870 MPa (126 ksi)
For heat-resistant steel, the basic tensile strength level is set out as 980 MPa (142 ksi) and the Charpy V-notch impact requirement is set out as 43 J (32 ft-lb).
Documentation and Marking: All materials shall be identified with the name of the manufacturer and the material grade and size. The company name must be permanently marked on the material, either directly or by stamping or engraving.
It is important that the purchaser ensure the material supplied is in accordance with the ASTM A484M-1998 standard. This is particularly important for chemical and mechanical requirements, as well as size, shape and tolerances. The information must be obtained in order to properly qualify the material to be used in a specific application.
