An experimental study on stress corrosion behavior of A131/A and A131/ AH32 low carbon steels in simulated seawater

摘要

Stress corrosion behavior of ASTM A131/A and A131/AH32 steels were investigated in simulated seawater (SSW) through slow strain rate test (SSRT), static load test in combination with fracture observation, and also electrochemical assessments. According to the results, both steel showed susceptibility to stress corrosion cracking (SCC) in SSW but the SCC susceptibility was higher In steel grade A131/AH32. Scanning electron microscopy (SEM) observation of fractured surfaces exhibited SCC occurrence on both steel. The application of tensile stresses in the elastic range caused an increase in corrosion rate of the two steel in marine environments, however, the corrosion potential presented no changes. In the tensile stress of 70% of yield stress, the A131/AH32 steel demonstrated a higher increase in the corrosion rate than that of the grade A131/A steel. It was found that the general corrosion rate of steel grade A131/A was higher than that of grade A131/AH32 steel in the marine environment, and the reason was attributed to the differences on the steels' alloying elements in particular on carbon content.