VALVE SEAT FOR INTERNAL COMBUSTION ENGINE AND ITS PRODUCTION METHOD

摘要

PROBLEM TO BE SOLVED: To provide a valve seat in which wear resistance is secured and machinability is improved by optimizing the base structure without dispersing expensive hard grains, and the cost reduction of can be attained. SOLUTION: This valve seat has a metallic structure composed of a bainitic single phase only or a mixed phase of bainite and martensite only, in which the area ratio between bainite and martensite in the cross-section is further controlled to (100:0) to (50:50), and also, the base hardness lies in the range of 250 to 850 Hv.