Effect of a current pulse on the thermal fatigue behavior of cast hot work die steel

The effect of current pulse on the thermal fatigue (TF) behavior of cast hot work die (CHWD) steel was investigated. The CPT during the TF cycles of the samples can delay the crack nucleation and reduce the crack propagation velocity. It can seen that the circular heat affected zone is formed at the notch root of the sample treated with current pulse. The superfine microstructure which is advantageous to enhancing the obdurability of the materials is formed at the notch root by the CPT, thereby it can promote the energy required when the cracks nucleate in the notch root and can suppress the growth of the cracks.