| 摘要 |
This sintered alloy is used for the valve sheet of engine for operation with lead-free gasoline. This alloy provides a good workability and sinterability, prevention of contamination of the furnace by vaporization of lead during sintering process. This sintered alloy comprises 0.5 to 1.0wt.% C, 0.5 to 1.5wt.% Pb, 1.0 to 2.0wt.% Ni, 1.0 to 3.0wt.% Mo, 5.0 to 11.0wt.% Co, 0.5 to 1.0wt.% MnS, and the balance of iron. This alloy is produced by the processes of compacting a powder mixture having the same chemical composition as above as a starting material under 50 to 85KN/cm2, pre-sintering at 750 to 900deg.C for 30 to 60min under the atmosphere of reduction, compacting the pre sintered mixture under 80 to 110KN/cm2, final sintering at 1,100 to 1,200deg.C for 30 to 60min under the atmosphere of reduction, quenching at 800 to 900deg.C for 60 to 120min, and tempering at 500 to 600deg.C for 60 to 120min.
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