CAM LOBE MEMBER, CAMSHAFT USING THE SAME AND METHOD FOR PRODUCING CAM LOBE MEMBER

摘要

A cam lobe member which comprises an iron based sintered alloy which contains 0.3 to 5.0 mass % of Ni, 0.5 to 1.2 mass % of C, 0.02 to 0.3 mass % of at least one of B and P, and the balanced amount of inevitable impurities, has a hardness of the peripheral surface thereof of HRC 50 or more, and has a density of 7.5 g/cm<3> or more; and a method for producing the cam lobe member which comprises providing an iron based alloy powder prepared so as to have the above composition of an iron based alloy, repeating two or more times a compression forming step of forming the alloy powder by compression into a prescribed cam lobe shape and a sintering step of sintering the resultant formed article, and then quenching and tempering the sintered article. The above iron based sintered alloy may further contain 2.5 mass % or less of Mo. The cam lobe member is excellent in the resistance to sliding such as abrasion resistance, scuffing resistance and pitting resistance, and thus can be suitably used for an engine to be operated under heavy load.