Sumitomo Metal Industries, Inc.

Mitsubishi Jukogyo Kabushiki Kaisha

Kazuo Yamanaka

Hiroo Nagano

Toshio Yonezawa

Hiroshi Susukida

Takao Minami

Nobuya Sasaguri

Kichiro Onimura

Yasutaka Okada

Mamoru Inoue

Katsuji Kawaguchi

Haruhiko Kajimura

Tsuyoshi Kodama

Nobukatsu Fujino

Yaautaka Okada

Takeo Harada

Takaya Kusakabe

A zirconium alloy which has good creep strength and bending properties as well as improved corrosion resistance in nitric acid solutions of low, medium, and high concentrations and which can withstand stress corrosion cracking in highly concentrated nitric acid solutions even under a high anodic potential is disclosed. The zirconium alloy consists essentially of, by weight percent:

Zirconium-titanium and/or tantalum oxygen alloy

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

Herein disclosed is a method and an apparatus for judging the fitness of a steel composition for a particular casting practice in order to prevent excessive segregation of manganese and phosphorous in the course of the casting. We have discovered that the simultaneous segregation of manganese and phosphorous tends to cause the formation of bainite and/or martensite in steel plate product during the cooling of the steel plate after rolling. When the manganese and phosphorous concentrations satisfy the following requirement (1):

Method for judging the fitness of a steel composition to a casting

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Minooshi, Japan

Kazuo Yamanaka