Sumitomo Metal Industries, Inc.

Takeo Kudo

Yasutaka Okada

Kunihiko Yoshikawa

Akio Ikeda

Taishi Moroishi

Hiroo Ohtani

Yoshio Tarutani

Masaaki Igarashi

Akira Seki

Shigeki Azuma

Nobuo Otsuka

Masaru Nishiguchi

Tadashi Fukuda

A corrosion-resistant austenitic alloy suitable for use in heat transfer tubes for heat-recovery boilers which withstands uniform corrosion, intergranular corrosion, and stress corrosion cracking in refuse-fired boilers and black-liquor combustion boilers. The alloy consists essentially, on a weight basis, of C: not more than 0.05%, Si: not more than 4%, Mn: not more than 7.5%, Ni: 25-55%, Cr: more than 20% and not more than 35%, Mo: an amount satisfying the following inequality (1) when Mn(%).ltoreq.2.5 or inequality (2) when 2.5.ltoreq.Mn(%).ltoreq.7.5,

Corrosion-resistant alloy heat transfer tubes for heat-recovery boilers

A high-Cr, high-Mo duplex stainless steel having excellent corrosion resistance as well as improved toughness and workability has a chemical composition which consists essentially, on a weight basis, of C: 0.03% or less, Si: 0.4% or less, Mn: 2.0% or less, Cr: 26.0-30.0%, Ni: 5.0-9.0%, Mo: 3.0 -4.5%, N: 0.10-0.35%, Al: 0.01-0.04%, optionally one or both of Cu and W in a total amount of 0.05-3.0% and/or one or more elements selected from Ca, B and Ce in a total amount of 0.001-0.01%, and a balance of Fe and incidental impurities, wherein the following inequality (1) is satisfied:

Duplex stainless steel having improved corrosion resistance

A sintered stainless steel exhibiting improved resistance to stress corrosion cracking which comprises a matrix phase and a dispersed phase and a process for manufacturing same are disclosed. The dispersed phase is of an austenitic metallurgical structure and is dispersed throughout the matrix phase which is comprised of an austenitic metallurgical structure having a steel composition different from that of the dispersed phase or a ferrite-austenite duplex stainless steel.

Sintered stainless steel and production process therefor

A precipitation-hardening Ni-base alloy exhibiting improved resistance to corrosion under a corrosive environment containing at least one of hydrogen sulfide, carbon dioxide and chloride ions and method of producing the same are disclosed. The alloy is of the .gamma.'-phase, or (.gamma.'+.gamma.')-phase precipitation hardening type in which Ti is restricted to less than 0.40% and is comprised of:

Precipitation-hardening nickel-base alloy and method of producing same

A sintered stainless steel and sintered seamless steel pipe exhibiting improved resistance to stress corrosion cracking are disclosed. The metallurgical structure comprises a matrix phase and a dispersing phase, which are different from each other in their metallurgical structures, the matrix phase comprising a substantially single ferritic structure, and the dispersing phase comprising a structure selected from the group consisting of an austenitic structure, an austenitic+ferritic dual phase structure, an austenitic+martensitic dual phase structure, and an austenitic+ferritic+martensitic triple phase structure. The sintered seamless stainless steel pipes are useful as heat exchanging tubes and piping to which sea water or industrial water is fed.

A process for manufacturing high strength deep well casing, tubing, and drill pipes, which have improved resistance to stress corrosion cracking is disclosed. The process comprises the steps of preparing an alloy composition which is:

Process for making high strength deep well casing and tubing having

An alloy useful for manufacturing high strength deep well casing, tubing and drill pipes for use in oil-well operations is disclosed. The alloy exhibits improved resistance to stress corrosion cracking in the H.sub.2 S--CO.sub.2 --Cl.sup.- environment, which comprises the following alloy composition:

Alloy for making high strength deep well casing and tubing having

An alloy useful for manufacturing high strength deep well casing, tubing and drill pipes for use in oil-well operations is disclosed. The alloy exhibits improved resistance to stress corrosion cracking in the H.sub.2 S--CO.sub.2 --Cl.sup.- -environment, which comprises the following alloy composition:

An alloy useful for manufacturing high strength deep well casing, tubing and drill pipes for use in oil-well operations is disclosed. The alloy exhibits improved resistance to stress corrosion cracking in the H.sub.2 S-CO.sub.2 -Cl.sup.- environment, which comprises the following alloy composition:

An alloy useful for manufacturing high strength oil-well casing, tubing and drill pipes for use in oil-well operations is disclosed. The alloy exhibits improved resistance to stress corrosion cracking in the H.sub.2 S--CO.sub.2 --Cl.sup.- environment, which comprises the following alloy composition:

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Nishinomiya, Japan

Takeo Kudo