超临界CO_2对钢材的腐蚀实验研究

EXPERIMENTAL STUDY OF CORROSION OF STEEL IN SUPERCRITICAL FLUID CO_2

采用静态高温高压釜及SEM现代分析测试手段,在分析超临界CO2存在形式及与原油、水交互作用的基础上, 进行了超临界CO2时钢材的腐蚀实验研究。结果表明,在腐蚀系统SCF-CO2气相中,存在CO2腐蚀现象;液相中,腐蚀速率随压力增加而上升,12 MPa达到峰值后下降。在纯水中12 MPa时,液相和气相中的腐蚀速率趋于一致,腐蚀形貌表现为腐蚀瘤。30％的原油含量可在液相促进钢材腐蚀,腐蚀形貌表现为腐蚀瘤与腐蚀坑并存;但随含油量增加,会抑制钢材腐蚀。

With the static high pressure and high temperature kettle and the SEM method, and based on the analysis between the supercritical fluid CO2 and the interaction of the water and oil, the corrosion experimental study for the N80 steel grade in the supercritical fluid CO2 was investigated. The results were show that the CO2 corrosion was found in the SCF- CO2 gas phase. In the liquid phase, the corrosion rate was accelerated with the increasing of pressure; it got the peak at 12 MPa and then down. In the medium of pure water, the corrosion rate in the gas was agreed with the corrosion rate in the liquid at 12 MPa, the tubercules were observed in corrosion film. The corrosion rate in the liquid was accelerated if the crude oil content was 30%. The tubercules and poles were found in the corrosion film together. The CO2 corrosion of steel was restrained with the increasing of the oil content.