LAUSR

In order to obtain the products with high strength and ductility, the hot stamping technology of TRIP steel has been getting more attention in recent years. In this study, the effects of cooling rate on the mechanical properties of a typical TRIP780 steel used in hot stamping process were investigated with tensile tests, bending tests and impact tests. It was found that even though a lower cooling rate for the quenching of TRIP780 steel led to the formation of the bainite and ferrite mixture phases, the mechanical properties of the material containing these phases were similar to those of the material containing martensite only. TRIP780 steel exhibited twice the elongation with a similarly high strength as compared with the conventional boron steel, and its mechanical properties are insensitive to cooling rate, which was approved by the hot stamping experiment of a U-cap part.