Sintered sprocket for silent chain and production method therefor

摘要

A sintered sprocket has a high overall density and excellent contact pressure resistance. The sprocket is produced from a sintered alloy selected from the following alloys ((1) to (3)), is densified to have a relative density of 95% or higher in the surface layer of the gear teeth by forming by rolling, having a surface hardness of 700 HV or higher, and is useful for a crankshaft, a cam shaft, a balancer shaft, or a water pump shaft of an internal combustion engine:
(1) an Fe-Mo-C based sintered alloy containing Mo at 1.0 to 2.0% by mass;(2) an Fe-Mo-Ni-C based sintered alloy containing Mo at more than 1.0 and not more than 2.0% by mass, and Ni at more than 1.0 and not more than 2.5% by mass, or(3) an Fe-Mo-Ni-Cu-C based sintered alloy containing Mo at 0.3 to 1.0% by mass, Ni at not less than 1.5 to less than 3.0% by mass, and Cu at 1.0 to 2.5% by mass.