Effects of Temperature and Strain Rate on Tensile Properties of TWIP Steel

The effects of temperature and strain rate on tensile properties of twining induced plasticity (TWIP) steel were investigated by tensile test.The results show that the strength gradually decreased and the plasticity gradually increased with the increase of the temperature,the strain hardening exponent reached and stayed at a relatively high level with the development of true strain,suggesting that the uniform deformation capability of TWIP steel was enhanced,which led to its global plasticity increase.With the increase of the strain rate,the flow stress increased and the plasticity decreased,but the tensile strength kept almost unchanged.The plateau zone in the strain hardening rate curve was obviously shortened,meaning that the twinning was suppressed and the maximum strain hardening rate was reached at a smaller strain.Moreover,the peak value of strain hardening exponent,the uniform deformation ability and the global plasticity dropped with the increase of the strain rate.