| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a valve seat material made from an iron-based sintered alloy for an internal combustion engine, which is suitable for an engine using gas fuel and is superior in abrasion resistance. <P>SOLUTION: This valve seat material includes hard particles of 10-60% by mass% dispersed in a matrix phase, wherein the matrix phase includes 0.3-1.5% C and one or more elements selected from among Ni, Co, Mo, Cr and V, in a total amount of 1 to 20%; and the hard particles have a composition comprising one or more intermetallic compounds from among an intermetallic compound containing Fe, Mo and Si as main components, an intermetallic compound containing Co, Mo and Si as main components and an intermetallic compound containing Ni, Mo and Si as main components, 1-15% Si, 20-60% Mo, 10-70% one or more elements selected from among Cr, Ni, Co and Fe, and the balance unavoidable impurities; and have Vickers' hardness of 500HV 0.1 to 1,200HV 0.1: has a density of 6.7 g/cm<SP>3</SP>or higher: and a radial compression strength of 350 MPa or higher. Thereby, the valve seat material has excellent abrasion resistance even in an environment of a gas fuel engine and has improved aggressiveness to the opposite material. The valve seat material may include a solid lubricant. <P>COPYRIGHT: (C)2007,JPO&INPIT |
