元素硫沉积环境中P110钢腐蚀特征的对比

Comparative Research on Sulfur Deposition of Corrosion Behavior of P110 Tube and Casing Steel

通过模拟普光气田元素硫沉积环境,应用腐蚀失重法探讨了油套管用P110钢在不同温度、不同酸性条件硫沉积环境中的腐蚀失重规律,并辅以扫描电镜、能谱等技术研究了腐蚀产物膜的形貌、成分及结构。结果表明:P110钢在元素硫沉积的各环境条件中腐蚀速率极高;同时,由于两相中P110钢的腐蚀机理存在差异,在相同温度、相同酸性条件中硫相的腐蚀速率高于液相;随着腐蚀溶液初始酸性的增强,H+去极化作用增强,且内、外层腐蚀产物膜的硫含量均有所降低,对基体的保护性变差,腐蚀程度逐渐加重。

By simulating the environment of PUGUANG gas field and adjusting the temperature and acidity of the experimental system, corrosion rate of Pl10 steel was investigated using the weight loss method. Scanning electron microscope （SEM）, energy disperse spectroscopy （EDS） were applied to characterize the microstructure and composition of the corrosion products. Results show that Pll0 steel exhibited very high corrosion rate of Pl10 steel in the environments with sulphur deposition. The corrosion rate in the sulfur phase is higher than that in the solution phase because of the difference in corrosion mechanisms. The corrosion rate can be accelerated as the increasing of the initial acidity of the solution, which causes the enhanced depolarization of H＋ and the decreased content of sulfur in the inner and outer films, respectively.