应变速率和环境介质对2205双相不锈钢应力腐蚀开裂行为的影响

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

通过慢应变速率试验,研究了应变速率对2205双相不锈钢在3种环境介质中应力腐蚀开裂(SCC)行为的影响。结果表明:当应变速率为1.5×10^(-5)s^(-1)时,2205双相不锈钢在蒸馏水和在海水溶液中未发生SCC,其在含Cl^(-)海水混合溶液中的拉伸断口呈典型的SCC形貌特征;在含Cl^(-)海水混合溶液中,当应变速率大于2×10^(-5)s^(-1)时,2205双相不锈钢的应力腐蚀敏感性系数小于25%,处于安全区,当应变速率为1×10^(-5)~2×10^(-5)s^(-1),其应力腐蚀敏感性系数处于危险区,2205双相不锈钢可能会发生SCC,当应变速率减小至1×10^(-5)s^(-1)时,其应力腐蚀敏感性系数为25%~35%,处于危险区和脆断区,2205双相不锈钢会发生SCC。

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.