Development and Microstructure Observation of 780MPa Cold Rolling TRIP-aided Steel

780 MPa cold-rolled TRIP steel was devoloped, and partial heat treatment conditions were pre-established according to actual conditions of factory production line.The optimal heat treatment conditions for the Fe-C-Si-Mn testing steel to obtain excellent strength-ductility balance were investigated by means of thermal simulation tests on Gleeble-3800 and then the microstructures were studied especially in residual austenite distribution.