Mitsubishi Jukogyo Kabushiki Kaisha

Sumitomo Metal Industries, Inc.

Mitsubishi Kinzoku Kabushiki Kaisha

Hiroshi Susukida

Toshio Yonezawa

Hiroo Nagano

Kazuo Yamanaka

Takao Minami

Nobuya Sasaguri

Kichiro Onimura

Yasutaka Okada

Katsuji Kawaguchi

Mamoru Inoue

Kensho Sahira

Hisataka Kawai

Ichiro Tsuji

Toshio Kojima

Toshiki Takeiri

Hitomi Itoh

Yaautaka Okada

Makoto Yuge

Takaya Kusakabe

A nickel-chromium alloy excellent in a stress corrosion cracking resistance which is obtained by carrying out an annealing treatment under specific conditions, said alloy having the following composition:

Nickel-chromium alloy in stress corrosion cracking resistance

An alloy for heat transfer pipes excellent in an alkali stress corrosion cracking resistance which is obtained by heating and retaining said alloy at a temperature within the range of a temperature (T.degree.C.), at which a carbide in said alloy is thoroughly solubilized, to T+100.degree. C. for 1 minute or more; cooling it once to a level of 200.degree. C. or less; and carrying out a thermal treatment under conditions within a hatched range Z in FIG. 2, said alloy comprising: in terms of % by weight, 0.15% or less of C; 1.0% or less of Si; 1.0% or less of Mn; 25 to 35% of Cr; 40 to 70% of Ni; 0.5% or less of Al; 0.01 to 1.0% of Ti; 0.5 to 5.0%, in all, of one or more of Mo, W and V; 0.30% or less of P; 0.020% or less of S; and the residue of Fe and impurities.

Method for thermal treatment of alloy for heat transfer pipes

A method for a thermal treatment of a nickel based alloy, characterized in that said nickel based alloy for a material which will be subjected to a high-temperature and high-pressure water or vapor comprises, in terms of % by weight, 58% or more of Ni, 25 to 35% of Cr, 0.003% or less of B, 0.012 to 0.035% of C, 1% or less of Mn, 0.5% or less of Si, 0.015% or less of P, 0.015% or less of S, and the residue of Fe and usual impurities; in a first thermal treatment process, said nickel based alloy is heated and retained at a temperature of T.degree. C. to (T+100).degree.C. and is cooled at a cooling rate of a furnace cooling rate or more; and in a second thermal treatment process, said nickel based alloy is then retained at a temperature of 600.degree. to 750.degree. C. and at a temperature within a sensitization recovery range for a period of 0.1 to 100 hours and is cooled at a cooling rate of said furnace cooling rate or more.

Method for thermal treatment of nickel based alloy materials

A heat resistant nickel base alloy which is excellent in not only hot and cold workability but also high temperature strength properties and which also possesses satisfactory oxidation resistance. The nickel base alloy consists essentially of 0.001-0.15 percent carbon, 0.0005-0.05 percent calcium, 20.0-126.0 percent chromium, 4.7-9.4 percent cobalt, 5.0-16.0 percent molybdenum, 0.5-4.0 percent tungsten, with the total of molybdenum plus tungsten being from 9.0 to 16.5 percent, and the balance nickel and inevitable impurities. The alloy may further contain one selected from the group consisting of (1) 0.3-1.5 percent aluminum and 0.1-1.0 percent titanium, (2) 0.001-0.30 percent at least one of yttrium and rare earth elements, and (3) 0.01-1.0 percent at least one of niobium, vanadium and tantalum, whereby the aforementioned characteristics are further enhanced.

Heat resistant nickel base alloy excellent in workability and high

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Takasago, Japan

Hiroshi Susukida