Stain rate sensitivity of deformation behavior in various sheet steels were investigated in order to find out the suitable steel for automotive anti-crash parts. Dual phase steels consisted of ferrite and martensite phases absorbed higher energy at strain rate of 2 × 103/s with lower yield strength at strain rate of 2 × 10-2/s, compared with other steels. Higher energy absorption of dual phase steels was due to high strain rate sensitivity of yield strength and n-value. Increase of volume fraction or large surface area of martensite phase in dual phase steel led higher strain rate sensitivity in work hardenability as well as yield strength.
