Abstract: The specimens of Si-Mn low carbon steel are processed into transformation induced plasticity(TRIP) and dual phase(DP) steel separately by different heat treatment. Then strain rate 0.001 s–1, 630 s–1, 1 490 s–1and 0.001 s–1, 560 s–1, 1 340 s–1 are studied by electronic universal testing machine and rotation disk bar-bar tensile impact apparatus separately. The results show that：The yield strength and tensile strength of TRIP and DP steel increase with increasing strain rate. Deformation localization in high strain rate leads to lower uniform elongation of TRIP and DP steel comparing with static tensile. Adiabatic heating in high strain rate causes uniform elongation and fracture elongation of TRIP steel in 1 490 s–1 and DP steel 1 340 s–1 are higher than that of TRIP steel in 630 s–1 and DP steel 560 s–1. The fracture elongation of DP steel in dynamic is bigger than that in static because adiabatic heating plays a leading role. TRIP steel is opposite since residual austenite transforms martensite.

Key words: Dual phase steel, Dynamic property, Transformation induced plasticity (TRIP) steel