Effect of Cu, Cr and Ni on mechanical properties of 0.15 wt.% C TRIP-aided cold rolled steels

Cold-rolled steels based on 0.15C–1.5Mn–1.5Si–0.5Cu containing Cr or/and Ni were prepared, and intercritical annealing and isothermal treatment, were carried out. The addition of Cu or Cu+Ni resulted in a large increase of the retained austenite volume fraction as well as an improvement of elongation and the strength-ductility balance. However, the addition of Cr or Cu+Ni showed a dual-phase deformation behavior having higher tensile strength and lower elongation.