Abstract: Microstructure and hardness along the radial direction of the 16MnCr5 low carbon alloy steel camshaft after carburizing and quenching and low temperature tempering process were studied by means of OM, SEM, XRD and hardness test. The results show that the 940 ℃ carburazing period is suitable for 16MnCr5 steel. Microstructure of the camshaft changes significantly along the radial direction, as the surface structure is high-carbon acicular martensite and 10% retained austenite with hardness reaching 750 HV and effective hardened layer depth of above 1.5 mm, and the matrix structure is a mixed structure of bainite and low carbon martensite.

Key words: 16MnCr5 steel, carburizing, camshaft, microstructure