Toshiba Ceramics Co., Ltd.

Sumitomo Metal Industries, Inc.

Toshiyuki Hirao

Sei Hiraki

Kazumi Arakawa

Isao Imai

Kenji Sugiura

Kouichi Sueyoshi

Takao Suzuki

Toshitsugu Ishii

Hajime Yamashita

Masatoshi Yamazaki

Satoshi Kuroki

Ken Nakai

Metal nitride powder is prepared by heating a mixture substantially containing powder of a metal oxide or a metal hydroxide in a mixed gas of ammonia gas (NH.sub.3) and a hydrocarbon gas (CmHn) at a temperature ranging from 1300.degree. C. to 1,600.degree. C., in which the mixed gas has a ratio of ammonia gas (NH.sub.3) to hydrocarbon gas (CmHn) translated into CH.sub.4, ranging from 10 (NH.sub.3) to 1.0 (CH.sub.4) to 2,000 (NH.sub.3) to 1 (CH.sub.4), by volume. The metal nitride powder contains lesser amounts of oxygen and carbon.

Process for preparing metal nitride powder

A silicon aluminum oxynitride containing refractory for use in continuous casting is placed between a mold and a tundish and is formed by sintering an admixture of silicon nitride (Si.sub.3 N.sub.4), aluminum nitride (AlN), boron nitride(BN), and a mineral clay. The refractory further includes aluminum oxide(Al.sub.2 O.sub.3).

Refractory for continuous casting

A walking beam type heating furnace for steels has a conventional skid pipe through which a coolant flows, a skid button made of a ceramic material, a base fixed to an upper portion of the skid pipe, an attachment frame attached to the base for holding the skid button in its supporting position, and a thermal insulating material placed at a bottom portion of the skid button for supporting the skid button. The thermal insulating material has a high strength, high density, low thermal conductivity and high coefficient of thermal expansion such as quartz glass, vycol glass, hard glass and soda lime glass.

Skid button structure

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Kariya, Japan

Toshiyuki Hirao