Iron-base sintered alloy for valve seat
AssigneeToyota Jidosha Kogyo Kabushiki Kaisha
InventorsKametaro Hashimoto, Kenji Ushitani, Youichi Serino, Tetsuya Suganuma, Seishu Mitani, Kunizou Imanishi
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Abstract
Iron-base sintered alloy for the valve seats of internal combustion engines is an iron-base alloy powder containing, by weight, 6 - 20% chromium less than 2.0% nickel, and carbon 0.2 - 1.5%, together with at least one additive selected from among 0.3 - 1.5% manganese, 0.2 - 1.5% sulfur, 0.5 - 8% molybdenum, and 0.5 - 2.5% silicon, and molded to a sintered density of 6.2 - 6.8 g/cm.sup.3.
Claims9
Method of manufacturing an iron-base sintered alloy for use in valve seats which comprises the steps of adding 0.2- 15% carbon in the form of graphite powder, and at least two additives selected from the group consisting of 0.3- 1.5% manganese, 0.2- 1.5% sulfur, 0.5- 8% molybdenum, and 0.2- 2.5% silicon by weight to a constituent alloy in powder form having an iron base and containing 6- 20% chromium and 0- 2.0% nickel by weight, molding the resulting mixture to a required shape by applying pressure thereto, and then sintering the molding at a temperature of 1120.degree.- 1200.degree. C. to yield an alloy having a sintered density of 6.2- 6.8 g/cm.sup.3.
Dependencies are inferred from the claim text.