Effect of post weld heat treatment on wear resistance of hot forging cast steel die coated with surfacing layer

The wear resistance capability of die surfacing layer under different Post Weld Heat Treatments (PWHT) was analysed by Finite Element Method (FEM) simulation and experiments. Taking the hot forging process of crankshaft as example, a wear model of hot forging die coated with surfacing layer was established by the software DEFORM-3D. The simulation results indicate that the wear resistance capability of the die surfacing layer is optimal when tempering temperature and holding time are 550 degrees C and 4h respectively. To verify the wear calculation result, 16 groups of different PWHT orthogonal wear tests were performed under atmospheric condition at 400 degrees C. The wear test result shows a good agreement with the FEM simulation result. SEM observation of the wear debris shows that oxidative wear plays a dominant role in 400 degrees C among 16 specimens. Furthermore, when tempering temperature and holding time are 550 degrees C and 4h respectively, the alloy carbide dispersively distributes in the metallographic structure, which can improve the wear resistance of the surfacing.