The critical temperature for stress corrosion cracking for type 304 steel in chloride solutions based on competition concept between dissolution and cracking rates

Abstract

The crack growth rate, C, for Type 304 stainless steel was measured in-situ in 0.5M H2SO4 + 0.5M NaCl solutions at 25, 40 and 80° C. In this solution the steel suffers SCC thus C can be measured even at temperatures lower than the critical temperature for SCC, Tc, at and below which the steel will not suffer from SCC in the neutral chloride solutions. The crack growth rate, C, of SCC was determined in a certain range of potentials near Ecorr where the observed cracking rate, Cob, remained steady. This rate was found to be equal to the cracking rate measured in the neutral chloride solutions and is therefore applicable for use as the crack growth rate in the competition concept which states that SCC will not occur when dissolution rate exceeds cracking rate. Based on the competition concept the estimated Tc for Type 304 steel was 40-55° C which was nearly equal to 50° C measured in the previous work.