Haynes International, Inc.

Cabot Corporation

Narasi Sridhar

Paul Crook

Lee H Flasche

Disclosed is a nickel-base alloy for use under 'super oxidizing' environments, for example, concentrated sulfuric acid, fuming nitric acid, chromium acid and mixtures containing chromic acid. The alloy has good strength and may be precipitation hardened. Its thermal stability and weldability are excellent. The alloy has a high degree of resistance to pitting. A nominal composition contains, in percent by weight, about 20 chromium, about 2 copper, about 2 iron, about 2 molybdenum, about 5 silicon and the balance nickel plus normal impurities.

Corrosion resistant Ni- Cr- Si- Cu alloys

Disclosed is a duplex stainless steel containing about 25% chromium, about 2% copper, about 3% molybdenum, about 0.2% nitrogen, about 9% nickel and the balance iron plus modifying elements and impurities. In corrosion conditions, including severe pitting environments, the steel contains up to 3%, and preferably 0.2 to 1.0% niobium. The alloy is especially suited for use as a welding filler material. The steel, after welding, has improved Charpy impact properties, increased tensile ductility and corrosion resistance. The steel is also suited for use in the form of cast, wrought or powder products.

Tough weldable duplex stainless steel wire

Disclosed is a 'duplex' stainless steel especially suited for use in conditions requiring a high degree of wear and corrosion resistance; for example structural fasteners, such as nuts and bolts as used in chemical processing. The alloy typically contains, in weight percent, 12 cobalt, 20 chromium, 11 nickel, 5 silicon, 1.5 molybdenum, 2 copper, up to 0.2 nitrogen and up to 0.01 carbon. The 'duplex' structure preferably consists of about 30% ferrite and the balance essentially austenite.

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Carmel, IN, United States of America

Narasi Sridhar