The
transformation-induced
plasticity steel is a kind of steels for automobile by transformation-induced plasticity (TRIP) effect to make retained
austenite in plate under action of plastic
deformation induce martensite nucleation and formation, produce local hardening then deformation no longer concentrate at local, finally phase transformation uniformly extend to whole material to increase strength and plasticity of steel sheet. In typical TRIP steel, C content is 0.2%, Mn 1%～2%, and Si 1%～2%. Structure of TRIP steel consists of 50%～60% ferrite, 25%～40% bainite or minor martensite, and 5%～15% retained austenite by hot rolling deformation heat
treatment or cold rolling + heat treatment. The strength and toughness of TRIP steel are higher than that of dual phase steel and micro alloying steel. The production process and properties of TRIP steels, the effect of retained austenite, alloy elements and heat treatment on TRIP effect and research trend of TRIP steel are presented in this paper.