深海油气设施用22Cr双相不锈钢的氢致应力开裂敏感性

Hydrogen Induced Stress Cracking Susceptibility of 22Cr Duplex Stainless Steel Used in Deep Sea Oil and Gas Facilities

利用腐蚀电化学方法、四点弯曲和慢应变速率试验等研究了阴保电位、外加应力和氢含量对深海油气设施常用22Cr双相不锈钢氢致应力开裂敏感性的影响。结果表明:当阴保电位负于-990 mV(SCE,下同)时,22Cr双相不锈钢在海水中的析氢反应显著加速。随阴保电位负移和外加应力增大,22Cr双相不锈钢氢脆敏感性增加,在-1150 mV阴保电位下,当拉应力超过95%σ_(0.2)时,可能出现氢致裂纹;在98%σ_(0.2)加载条件下,双相不锈钢中氢含量为10.6~12.6 mg/L时,可能诱发氢致裂纹。

Using corrosion electrochemical methods,four-point bending and slow strain rate tests,the effects of cathodic potential,applied stress and hydrogen content on the hydrogen-induced stress cracking sensitivity of 22Cr duplex stainless steel commonly used in deep-sea oil and gas facilities were studied.The results showed that the hydrogen evolution reaction of 22Cr duplex stainless steel in seawater significantly accelerated when the cathodic protection potential was negative than-990 mV(vs.SCE,the same below).With the negative shift of the cathodic protection potential and the increase of the applied stress,the hydrogen embrittlement sensitivity of 22Cr duplex stainless steel increased.When the tensile stress exceeded 95%σ_(0.2),hydrogen-induced cracking might occur at a negative potential of-1150 mV.Under 98%σ_(0.2)loading condition,when the hydrogen content of duplex stainless steel reached 10.6-12.6 mg/L,hydrogen-induced cracking might be induced.