超级13Cr不锈钢在磷酸盐完井液中的应力腐蚀开裂敏感性研究

Stress Corrosion Cracking Sensitivity of Super 13Cr Stainless Steel in Phosphate Completion Fluid Environment

超级13Cr不锈钢常应用于高温井段,为明确其在高温磷酸盐完井液中的腐蚀及断裂风险,通过慢速率应变拉伸试验(SSRT)和高温高压电化学测试等,结合扫描电镜研究了超级13Cr不锈钢在高温磷酸盐完井液环境中的应力腐蚀开裂敏感性。结果表明:超级13Cr不锈钢在高温磷酸盐完井液环境下具有一定的应力腐蚀开裂敏感性,其应力腐蚀开裂机制为阳极溶解型;随温度升高,超级13Cr不锈钢表面的钝化膜稳定性下降,点蚀敏感性增加,应力腐蚀开裂敏感性增大。

The stress corrosion cracking （SCC） sensitivity of super 13Cr stainless steel in phosphate completion fluid at high temperature was studied by slow strain rate tensile （SSRT） test, high- temperature and high- pressure electrochemical analysis and scanning electron micro- scope. Results showed that super 13Cr stainless steel had a certain degree of SCC sensitivity in phosphate completion fluid at high temperature. The cracking mechanisms of which belonged to anodic dissolution type. With the increase of temperature, the stability of passivation films on super 13Cr stainless steel declined, while the sensitivity of pitting corrosion increased, which led to higher sensitivity of SCC.