Thermo-mechanical coupled analysis of hot press forming with 22MnB5 steel

Abstract

This paper mainly concerns the thermo-mechanical analysis to evaluate the process parameters in the hot press forming with the 22MnB5 sheet such as the austenitization temperature, transport and quenching time for enhancing the efficiency in the production cycle. It is noted that the transport time is most influencing process parameter in the hot press forming to increase production efficiency without sacrificing the strength of the final product. In addition, we newly proposed a scheme to reproduce the flow curves of the hot stamped 22MnB5 sheet with respect to the martensite fraction by correlating the numerical analyses and tensile test results. To take into consideration of the strength variation in the hot stamped door impact beam, entire part is partitioned into several domains on which adaptive flow curves are assigned with respect to the martensite fraction. It demonstrates a good agreement with experimental 3-point bending test with the hot stamped door impact beam when applying the proposed method adopting adaptive flow curves with respect to the martensite fraction.