Enhanced Mechanical Properties of a Hot-Stamped Advanced High-Strength Steel via Tempering Treatment

Abstract

The hot stamping process has an extensive range of applications due to its advantages over the traditionally used stamping techniques developed in the past. To enhance the mechanical properties of the indirectly hot-stamped parts, the quenching and partitioning (Q&P) process has been recently applied on boron-alloyed steel. In the current research, it was observed that the tempering treatment on the directly hot-stamped boron steel resulted in better mechanical properties and higher formability index compared with the reported results using the Q&P process. The nano-carbide formation and the dislocation annihilation during the tempering treatment were suggested as the evident reasons for the occurrence of the mentioned robust properties. The ease of the practical implementation of the tempering route together with the markedly enhanced mechanical properties of the tempered parts make the suggested method privileged. Additionally, the variations in the yield strength before and after tempering were quantitatively evaluated.