Effect of Cl− and rust layer on stress corrosion cracking behavior of X100 steel base metal and heat-affected zone in marine alternating wet/dry environment

Abstract

The influence of stress corrosion cracking (SCC) behavior of ×100 steel base metal (BM) and heat-affected zone (HAZ) with a rust layer under an alternating wet/dry condition was investigated. The results indicated that ×100 steel was highly susceptibility to SCC, especially the HAZ. When the concentration of Cl − exceeded 2 mol/L, the magnitude of the SCC susceptibility of ×100 steel increase was less. The corrosion product layer had an effect on electrochemical corrosion and SCC. Cl − deposited in the corrosion product layer can cause pitting, and an increase in local H − owing to acidification, this outcome might lead to an increase in SCC susceptibility. The SCC of ×100 steel involved the mechanism of anodic dissolution (AD) and hydrogen evolution (HE). • The SCC behavior of ×100 steel BM and HAZ were studied by a self-made alternating dry/wet stress corrosion test device. • The effect of high concentration Cl − on the SCC susceptibility of ×100 steel was systematically studied. • The composition of the rust layer and its effect on SCC behavior are clarified. • Comparative analysis of SCC mechanism of BM and HAZ under high Cl − concentration.