Valve system for internal combustion motor has a valve seat comprising matrix of iron-based sintered alloy and a dispersed powder of a silicon-chromium-molybdenum-cobalt intermetallic composition

摘要

The valve seat has a base element comprising a matrix of an iron-based sintered alloy and a dispersed powder of an Si-Cr-Mo-Co intermetallic composition. The powder has hardness HV600-HV1000 and mean particle diameter 20-70 microns . The matrix is 10-50 weight % of the total weight of the base element. Valve element has a base element comprising a martensitic steel matrix and a nitriding diffusion layer. The nitriding diffusion layer has hardness above HV500 and thickness greater than 20 microns . At least one or two elements selected from Ni, Cr, Co, Mo, Cu and V are added as constituents the matrix of the base element of the valve seat in an amount 1.0-20.0 weight % with respect to the total weight of the matrix. A solid lubricant is added to the base element of the valve seat on amount 0.1-5.0 weight % of the total weight of the base element of the valve seat. Copper, lead or a resinous material is infiltrated or impregnated into the base element of the valve seat. Independent claims are given for valve systems for internal combustion engines, and layouts of valves for internal combustion engines.