Effects of Strain Rate and Environmental Medium on Stress Corrosion Cracking Behavior of 2205 Duplex Stainless Steel

The effect of strain rate on stress corrosion cracking (SCC) behavior of 2205 duplex stainless steel in three environmental mediums was investigated through slow strain rate test. The results showed that when the strain rate was 1.5×10^-5 s^-1, no SCC occurred when 2205 duplex stainless steel was in distilled water and seawater solution, and its tensile fracture in seawater mixed solution containing Cl^- was typical SCC morphological characteristics. In seawater mixed solution containing Cl^-, when the strain rate was greater than 2×10^-5 s^-1, the stress corrosion susceptibility coefficient of 2205 duplex stainless steel was less than 25%, which was in the safe area. When the strain rate was 1×10^-5~2×10^-5 s^-1, its stress corrosion susceptibility coefficient was in the dangerous zone, 2205 duplex stainless steel might suffer from SCC. When the strain rate was reduced to 1×10^-5 s^-1, its stress corrosion susceptibility coefficient was 25%~35%, in the dangerous zone and brittle fracture zone, 2205 duplex stainless steel would suffer form SCC.