HIGHLY WEAR-RESISTANT VALVE SEAT FOR USE IN INTERNAL COMBUSTION ENGINE AND MANUFACTURING METHOD THEREFOR

摘要

A highly wear-resistant valve seat insert is provided. When an iron-based powder, a hard-particle powder, and a graphite powder are mixed to obtain a mixed powder, for formation of a layer on a valve-contacting face side, the hard-particle powder having an average particle size 15-50 μm, and the iron-based powder having an average particle size 15-50 μm are blended so a matrix part composition after sintering is a composition containing C: 0.3 to 2.0% by mass, one or more kinds selected from Co, Si, Ni, Mo, Cr, Mn, S, W, and V at 70% by mass or less in total, the balance being Fe and unavoidable impurities and a matrix part structure after sintering is a structure which contains hard-particles at from 10 to 65% by mass with respect to a total amount of a layer on a valve-contacting face side and disperses the hard-particles at 1000 particles/mm2 or more.

主权项

1. A highly wear-resistant valve seat insert for internal combustion engine, the valve seat insert for internal combustion engine comprising one layer or integrated two layers, made by an iron-based sintered body wherein
at least a layer on a valve-contacting face side of the valve seat insert has a matrix part composition which contains C: 0.3 to 2.0% by mass, contains one kind or two or more kinds selected from among Co, Si, Ni, Mo, Cr, Mn, S, W, and V at 70% by mass or less in total, the balance being Fe and unavoidable impurities, and a matrix part structure which contains hard-particles at from 10 to 65% by mass with respect to a total amount of the layer on the valve-contacting face side and disperses the hard-particles at 1000 particles/mm2 or more.