Effect of Processing on Microstructures and Properties in Cr Hot-Stamping Steel

摘要

A new designed hot-stamping steel by Cr alloying without B addition was developed in the present work.The effect of reheating temperatures and cooling rates on the mechanical properties was studied in the experimental samples in order to get information for the design of processing parameters.The experimental results show that the austenite grain would significantly growth when the reheating temper-attire was reached to 1100 °C, resulting in the obvious decrease in mechanical properties.It implies that the reheat temperature should be kept below 1100 °C during hot-stamping which requires optimizing design of materials composition and facility.If the reheating temperature was kept in two phase range of ferrite and austenite, the elongation of the sample was increased without obvious decrease in the tensile strength.The effect of cooling rate on the microstructures and mechanical properties was analyzed.The experimental results illustrated that the plasticity of the samples could be enhanced by introducing partial bainite to improve comprehensive properties.The designed Cr steel is a good candidate for hot-stamping application.