DESIGN AND INVESTIGATION ON THE HOT ROLLING TWIP STEEL WITH TRIP EFFECT
LIU Rendong1, 2) , SHI Wen3), HE Yanlin3), LI Lin3), WANG Fu1)
1) School of Materials and Metallurgy, Northeastern University, Shenyang 110819
2) Technology Center, Anshan Iron and Steel Group Corporation, Anshan 114009
3) School of Materials Science and Engineering, Shanghai University, Shanghai 200072
Cite this article:
LIU Rendong SHI Wen HE Yanlin LI Lin WANG Fu. DESIGN AND INVESTIGATION ON THE HOT ROLLING TWIP STEEL WITH TRIP EFFECT. Acta Metall Sin, 2012, 48(1): 122-128.
Abstract There exists obvious deficiency in traditional twining induced plasticity (TWIP) steel which exhibits excessive ductility but rather low strength. In order to improve the property, new composition of a test steel, i.e., Fe-18Mn-0.528Si-0.6C (mass fraction, %) steel is designed through increasing C content and decreasing Mn content upon the estimation result of stack fault energy and phase diagram calculation. That the γ→ε transformation may happen during deformation at room temperature in the designed steel is predicted through calculation. The microstructure, before and after tensile test, of the hot rolling test steel is analyzed with OM, XRD and TEM. It is shown that there occurs simultaneously TWIP and transformation induced plasticity (TRIP) effect in the steel treated by a special hot rolling process (rolling starting temperature 1100 ℃, finishing rolling temperature 850 ℃\linebreak and air cooling) and superior mechanical property with strength higher than 1 GPa and elongation rate higher than 60\% are then obtained which fit very well with the requirement of the third generation automobile steel. It is also revealed the existence of ε martensite obtained through quenching or induced by stress would damage the mechanical property.
Supported by National Basic Research Program of China (No.{\footnotesize\it 2010CB630802}) and National Natural Science Foundation of China (Nos.50934011 and 50971137)
