Toyo Kogyo Co., Ltd.

Kiyokazu Inmaru

Tsuyoshi Morishita

Junichi Yamamoto

Koji Yagii

Kenji Miyake

Toshio Yagi

A valve-seat material ideal for valve seats for vehicle-engine exhaust valves with no cobalt contained therein, superior in general use, has superior wear-resistance in high-temperature oxidizing atmosphere, and can be used independently of types of fuel to be used in the non-lead gasoline, lead-contained gasoline, L.P.G. or the like. The recession amount of the valve is extremely decreased and the wear resistance is remarkably improved.

Hard-particle dispersion type sintered-alloy for valve seat use

Method of fabrication of material suited for use in a thermal reactor according to which austenitic stainless steel is dipped in a bath of molten aluminium in addition of silicon and then receives heat treatment in specific temperature ranges, whereby preferential diffusion of silicon in the steel material is effected. The diffused silicon prevents diffusion of aluminium and ensures that thickness of plating layers remains at a value such that distortion of a plated element does not occur even after prolonged service.

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Higashihiroshima, Japan

Kiyokazu Inmaru