Fatigue Properties of Supersteel for Automobiles

The fatigue properties of 400 MPa grade supersteel, plain low carbon steel SS400 and microalloyed steel Q340TM were investigated through tensile-compression fatigue experiment with R = −1. The results indicate that the fatigue limit of the 400 MPa supersteel is higher than that of SS400 steel and close to that of the 340TM steel. According to the analysis of fatigue fracture, the fatigue striations of supersteel SS400 is thinner than that of SS400 steel and 340TM steel, and grain refinement can increase the fatigue limit.