Effect of Ni content on the tensile properties and strain-induced martensite transformation for 304 stainless steel

▶ The α′-martensite of the low Ni-content STS increased by the strain-induced martensite transformation. ▶ With decreasing Ni content, the tensile strength, elongation and strain hardening exponent all increased. ▶ The variation of the elongation and the yielding phenomenon was due to the different behavior of the phase transformation with respect to the tensile test temperature and the Ni content. ▶ The 8.3∼9.0 wt.% Ni STS underwent the phase transformation (γ → ɛ) in the beginning of the tensile deformation at −60 °C.