Quenching and Partitioning (Q&P) Die Quenching Processing of 30MnSiCrB6 Press Hardening Steel

Abstract

Press hardening steel (PHS) is increasingly being used for the manufacture of structural automotive parts. One of the most critical characteristics of PHS is a low residual ductility related to its martensitic microstructure. Recently, the application of quenching and partitioning (Q&P) processing to PHS has been shown to result in a significant improvement of the mechanical properties [1]. The present work focused on the use of Q&P processing to improve the ductility of PHS. The effect of the partitioning time on the microstructure and mechanical properties of a Q&P processed 30MnSiCrB6 PHS was analyzed. The Q&P processed 30MnSiCrB6 PHS contained a high volume fraction of C-enriched retained austenite, and excellent mechanical properties as compared to the standard 22MnB5 PHS grade. The considerable improvement of both the ductility and the bendability of the Q&P-compatible PHS should lead to an improved in-service ductility beneficial to passive vehicle safety.