Relationship among parameters evaluating stress corrosion cracking

The threshold stress, sigma(c), for sulfide stress corrosion cracking (SCC) of seven pipeline steels and five other steels, the critical stress, Sc, f or seven pipeline steels and two drill rod steels with various strengths an d the susceptibility to SCC, I-RA or sigma(f)(SCC)/sigma(f), for four pipel ine steels, two drill rod steels and five other steels were measured. The r esults showed that there are no definite relationships among sigma(c), S-C and I-RA or sigma(f)(SCC)/sigma(f). The threshold stress for hydrogen induced cracking (HIC) during charging wi th loading in the H2SO4 solution, sigma(c)(H), decreased linearly with loga rithm of the concentration of diffusible hydrogen c(0), i.e., sigma(c)(H)=A -B Inc(0) for four pipeline steels. sigma(c)(H) obtained with a special cat hodic current i(c), which was corresponding to the diffusible hydrogen conc entration during immersing in the H2S solution, were consistent with a, for sulfide SCC for four pipeline steers. Therefore, a, for sulfide SCC can be measured using dynamically charging in the H2SO4 solution with the special cathodic current i(c).