不同状态310S奥氏体不锈钢在H2S/CO2环境中的应力腐蚀行为

目的探究不同状态310S奥氏体不锈钢在H2S/CO2环境中的应力腐蚀行为。方法研究三种不同状态310S奥氏体不锈钢在湿H2S环境中的应力腐蚀行为和电化学测试,并探究影响310S应力腐蚀开裂的因素及其机理。结果经过冷变形处理后,310S奥氏体不锈钢的抗应力腐蚀性能有所提升,而900℃时效处理会使310S钢材更易遭受应力腐蚀的影响。此外,施加载荷会使材料的耐蚀性变差。在SSRT实验中,固溶处理后的试样应力腐蚀敏感性为88.1%,时效处理后则升高至91.5%,冷轧后则降低至85.3%。另外还观察到,裂纹通常起源于试样表面局部腐蚀处。通过准原位充氢-TEM实验发现,氢原子扩散进基体后,会促进位错运动,导致位错更易发生塞积,从而引发应力集中。结论冷轧态310S具有最好的耐蚀性能,其次为固溶态,时效态310S的耐蚀性能最低。在湿H2S环境下,冷轧态310S的应力腐蚀敏感性最低,时效处理则会提高试样的应力腐蚀敏感性。H原子进入到310S内部会促进位错的运动、增殖与塞积,导致应力集中,从而降低局部的耐蚀性能。

Stress Corrosion Behavior of 310S Austenitic Stainless Steel with Different States in H2S/CO2 Environment

The work aims to investigate the stress corrosion behavior of 310S austenitic stainless steel with different states in H2S/CO2 environment.The stress corrosion behavior and electrochemical test of 310S austenitic stainless steel with three different states in wet H2S environment were studied,and the factors and mechanism influencing the stress corrosion cracking of 310S were explored.The stress corrosion resistance of 310S austenitic stainless steel after cold deformation treatment was improved,while the 310S steel was more susceptible to stress corrosion after aging treatment at 900℃.In addition,the corrosion resistance of the material would be worse when the load was applied.In the SSRT experiment,the stress corrosion sensitivity of the sample after solution treatment was 88.1%,that after aging treatment was increased to 91.5%,and that after cold rolling was reduced to 85.3%.Moreover,it was also observed that the crack usually originated from the local corrosion on the sample surface.From the quasi in situ hydrogen charging-TEM,the diffusion of hydrogen atoms into the matrix would promote dislocation movement,which would lead to dislocation plugging and stress concentration.Cold rolled 310S has the best corrosion resistance,followed by solid solution,and aging 310S has the lowest corrosion resistance.In the wet H2S environment,the cold-rolled 310S has the lowest SCC sensitivity,while the aging treatment can improve the SCC sensitivity.When H atom enters 310S,it will promote the movement,proliferation and plug of dislocations,which will lead to stress concentration and reduce the local corrosion resistance.