Nippon Steel Corporation

Mitsuru Tanino

Ryuji Uemori

Toshihiro Hanamura

Jin-ichi Takamura

Hajime Komatsu

Susumu Takemura

A Ti-Al intermetallic compound is prepared from a mixture of about 40 to 52 atomic % Ti, about 48 to 60 atomic % Al, and 10 to 3000 atomic ppm of at least one of P, As, Se, or Te. The mixture is melted and then solidified. The solidified product is annealed to form a uniform microstructure.

Process for the preaparation of a Ti-Al intermetallic compound

A Ti--Al intermetallic compound has a compressibility of at least 25% at room temperature and a superior high temperature oxidation resistance and consists essentially of about 40 to 52 atomic percent of Ti, about 48 to 60 atomic percent of Al, and 10 to 1000 atomic ppm of at least one of P, As, Se, or Te.

Ti-Al intermetallic compound with Se

The present invention relates to a heat treatment process of high-carbon chromium-nickel heat-resistant stainless steels for the purpose of improving the creep rupture strength of the steel at temperatures over about 800.degree. C particularly at about 1000.degree. C. The feature of the present invention lies in that heat-resistant stainless steels containing 0.2 - 1.5% C, 15 - 40% Cr, 10 - 50% Ni, 5% or less Si, 15% or less Mn, with the balance Fe, and impurities are heated for 1 to 60 minutes in a temperature range from 1280.degree. C to 1350.degree. C and then quenched to room temperature at cooling rates higher than 200.degree. C/min. in order to produce the eutectic carbide structure consisted of the matrix metal and carbide phases in which M.sub.7 C.sub.3 -type carbide is contained not less than 25% by weight of the total weight of the carbides, that are present in the said eutectic carbide structure, at grain boundary triple points, along grain boundaries and within grains.

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Kawasaki, Japan

Mitsuru Tanino