Research on Q&P hot stamping process integrated with fractional cooling strategy

Abstract

Abstract Hot stamping technology has been widely used to produce high strength steel parts, but the elongation of the production is limited which leads to low ductility. In this paper, the quenching & partitioning treatment (Q&P) has been introduced into the existed hot stamping process to develop the Q&P hot stamping technology. Moreover, a fractional cooling strategy was also introduced, which improves the formability and helps to reduce the cooling requirement of the tool as well. By the presented process, the specimen was firstly quenched quickly to a suitable forming temperature by water spray method, then it was stamped and quenched inside the tool, and subsequently partitioned and secondly quenched to room temperature. The presented process can improve the elongation effectively and maintain the strength in a high level, which was proved by a series of Gleeble tests and real forming tests. OM and SEM observations were also provided to study the mechanisms of the process.