Characteristics of Residual Stresses Generated by Induction Heating on Steel Plates

This paper presents experimental and numerical investigations on the characteristics of residual stresses generated by induction heating (IH) on 12 mm thick steel plates. IH at 250 degrees C and 350 degrees C provided high tensile residual stresses in the heating field but high compressive stresses away from the heating field. The double heating case generated higher compressive residual stresses-around 200 MPa-than the single heating case because of the superposition of the compressive residual stresses. It will be expected to improve the fatigue performance of welded joints when IH is applied for repair work on existing steel structural members susceptible to fatigue damage. Numerical simulation models for predicting residual stresses by IH were proposed by adopting the body heat flux input and the surface heat flux input. They will be beneficial for identifying the optimum heating conditions, such as the target temperature and the heating field, for applying IH to the actual repair work of the steel structural members.