Constant strain-rate testing of AISI type 304 stainless steel in 0.5 M H2SO4 + 0.1 M NaCl solution at room temperature with controlled potential

The constant strain-rate (CSR) test method has been applied to investigate the stress corrosion cracking (SCC) susceptibility of AISI Type 304 stainless steel in 0.5 M H₂SO₄ + 0.1 M NaCl at 25°C within a range of controlled potentials. Cracks were found to form in two distinct potential regions: in the cathodic range, and in the passive potential region. A clear differentiation between the two observed types of cracks was attempted. Crack morphology, the measured current during straining and the reduction of area were used as criteria. SCC was found to occur essentially in the passive potential region; in the cathodic range the cracks were due to hydrogen embrittlement.