论文部分内容阅读
利用电化学动电位测试技术和高温高压失重法研究了15Cr合金油管在CO_2以及与H_2S共存环境下的腐蚀行为和变化趋势,分析了H_2S与CO_2不同时间间隔共存后对材料腐蚀性能的影响。结果表明:在实验溶液中先加入CO_2,当腐蚀电位稳定后再加入H_2S腐蚀介质时,材料阳极钝化区不稳定;当先加入CO_2且时间间隔10 min后加入H_2S介质时,材料阳极钝化区域呈现相对较稳定的状态,维钝电流密度相对减小。材料在应力状态下的腐蚀电位相对非应力状态明显下降,并且腐蚀电流密度右移,耐蚀性相对下降。高温高压实验结果表明,应力的存在促进了腐蚀程度的加剧,平均腐蚀速率明显增大。材料在加载80%σs应力且当H_2S浓度达1 MPa时,试样表面出现明显的点蚀坑,试样发生应力腐蚀断裂。
The corrosion behavior and changing trend of 15Cr alloy tubing in the presence of CO_2 and H_2S were studied by electrochemical kinetic potentiometry and high temperature and high pressure lossless method. The influence of H_2S and CO_2 coexistence on the corrosion performance was analyzed. The results show that when the corrosion potential is stable and then H 2 S corrosion medium is added, the anodic passivation zone of the material is unstable. When CO 2 is added and the H 2 S medium is added after the interval of 10 min, the anodic passivation zone Showing a relatively stable state, the dimension of the current density is relatively reduced blunt. Corrosion potential of the material in stress state relative to the non-stress state decreased significantly, and the corrosion current density to the right, the relative decline in corrosion resistance. The experimental results of high temperature and high pressure show that the existence of stress promotes the increase of corrosion and the increase of average corrosion rate. When 80% σs stress is applied to the material and obvious obvious pitting corrosion occurs on the specimen surface when H_2S concentration reaches 1 MPa, stress corrosion cracking occurs on the specimen.