SINTERED VALVE SEAT AND PRODUCTION METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a sintered valve seat which exhibits excellent high-temperature abrasion resistance in a high-load engine environment such as in a CNG engine or a heavy-duty diesel engine and to provide a method for producing the same. SOLUTION: The sintered valve seat is composed of a Co-based alloy having a composition of 48 to 60 mass% Mo, 3 to 12 mass% Cr, 1 to 5 mass% Si, and the balance being Co and inevitable impurities, and having a structure comprising 5 to 40 mass% of hard phase mainly formed of molybdenum silicides and integrally precipitated and dispersed in the Co-based alloy matrix and a Cr sulfide dispersing around the hard phase. COPYRIGHT: (C)2007,JPO&INPIT