17-4 Stainless Steel is one of the most widely used precipitation hardening (PH) grades in the world. While soft and ductile in the annealed condition, it is capable of high properties with a single precipitation or aging treatment. 17-4 is characterized by good corrosion resistance, high hardness, toughness and strength. 17-4 Stainless Steel can be machined in the annealed condition, however condition H1150M will yield best results. Post machining solution treatment of parts will be required prior to final hardening if machining in this condition. 17-4 can be successfully welded by common fusion and resistance methods, this alloy should not be joined by oxyacetylene welding. AWS E/ER630 filler metal is recommended if required. 17-4 is commonly used in both aircraft and gas turbines, nuclear reactors, paper mills, oil fields, and chemical process components.
Forte Precision Metals Stock offers high quality standards including: UNS S17400, AMS 5643, ASTM A564, and ASTM A693 Grade 630.
Forte Precision Metals Stock 17-4 PH, which is used where high strength and good corrosion resistance are required, as well as for applications requiring high fatigue strength, good resistance to galling, seizing and stress corrosion. Suitable for intricate parts requiring extensive machining and welding, and/or where distortion in conventional heat treatment is a problem. The corrosion resistance of 17-4 is superior to that of hardenable straight chromium grades such as 416. It approaches the corrosion resistance of the non-magnetic chromium-nickel grades. Corrosion resisting properties will be affected by such conditions as surface finish and aging heat treatment. Common applications include uses in aircraft and gas turbines, nuclear reactors, paper mills, oil field industry, and chemical process components.
Mechanical properties can be optimized with heat treatment. Very high yield strength up to 1100-1300 MPa (160-190 ksi) can be achieved.
The grade should not be used at temperatures above 572°F (300°C) or at very low temperatures. It has adequate resistance to atmospheric corrosion or in diluted acids or salts where its corrosion resistance is equivalent to Alloy 304 or 430.