材料期刊网

目的：研究TP110 TS油管钢在酸性气田环境中的应力腐蚀开裂行为。方法通过模拟酸性气田环境,采用动电位极化法、电化学阻抗法、电化学充氢、恒载荷浸泡试验和慢应变速率拉伸试验等方法进行研究。结果在酸性气田环境中,100℃时TP110 TS钢中的含氢量大幅度降低,氢脆作用减弱,导致其应力腐蚀敏感性低于60℃。 TP110 TS钢在100℃的酸性气田环境中,当拉应力超过70％σs 时才表现出一定的应力腐蚀敏感性,表明该材料在实际使用过程中应力水平应保持在70％σs 以下,但当温度降低到60℃,其安全应力门槛值要降为50％σs。结论 TP110 TS钢在酸性气田环境中的应力腐蚀机制是阳极溶解与氢脆的混合机制。拉应力的存在会缩短TP110 TS钢的耐腐蚀寿命,且拉应力越大,耐腐蚀寿命越短。

ABSTRACT:Objective To study the stress corrosion cracking (SCC) behavior of TP110TS oil pipeline steel in the simulated sour
gas field environment. Methods Potentiodynamic polarization, electrochemical impedance method, electrochemical hydrogen char-ging, constant load test methods such as immersion test of constant-loading specimen and slow strain rate tensile test were used for research in the simulated sour gas field environment. Results It showed that the amount of hydrogen in the TP110TS oil pipeline steel in the sour gas field environment was substantially decreased when the temperature was 100 ℃, the hydrogen embrittlement effect was diminished, which resulted in the decreased stress corrosion sensitivity as compared to that at 60℃. In the sour gas field environment with a temperature of 100℃, the TP110TS steel showed some stress corrosion sensitivity only when the tensile stress on the steel exceeded 70%σs . It showed that the stress level of the material in the process of actual use should be kept below 70%σs . However, when the temperature was reduced to 60 ℃, its security stress threshold value should be decreased to 50%σs . Conclu-sion The SCC mechanism of TP110TS oil pipeline steel in the sour gas field environment was mixed-controlled by both anodic disso-lution (AD) and hydrogen-induced (HE), and the existence of the tensile stress shortened the corrosion life of the TP110TS steel and the greater the tensile stress was, the shorter the corrosion life became.