Rolling contact fatigue performance of ductile iron improved by electric contact surface strengthening

This paper deals with the improvement of the rolling contact fatigue (RCF) performance of ductile iron by electric contact surface strengthening. Electric contact strengthening was based on the application of the contact resistance heating between the electrode and workpiece to enhance the surface performance. The microstructure, microhardness, residual stress and RCF resistance were investigated using optical microscope, field emission scanning electron microscope, Vickers hardness (HV0.1), X-ray diffraction and rolling contact testing machine. The microstructure, high surface hardness and compressive stress distribution were responsible for the improvement of the RCF resistance of ductile iron.