含硫原油对X65钢管道顶部腐蚀实验研究

Experimental Study on Top-of-Line Corrosion Behavior of X65 Steel by Crude Oil

利用高温腐蚀试验箱,模拟输油管道的腐蚀环境,研究X65钢管道在含硫原油中的腐蚀行为。利用扫描电子显微镜(SEM)、能谱分析(EDS)和X射线衍射(XRD)等分析技术,对比分析不同腐蚀时间、温度下样品腐蚀产物的组织形态与成分,研究腐蚀时间及原油温度对X65钢管的腐蚀影响规律。结果表明,随着腐蚀时间的延长,试样腐蚀速率先增大后减小,最后趋于某一定值;温度对试样腐蚀速率影响较明显,由于重力作用腐蚀产物呈下坠状附着在试样表面,腐蚀形态为全面腐蚀。在低温时腐蚀产物主要成分为铁的氧化物,在温度较高时腐蚀产物中出现Fe_2S等具有保护性的腐蚀产物。

The corrosion behavior of different locations of X65 steel oil pipeline was investigated using a high-temperature corrosion test chamber, which aims to simulate the real corrosive environments of oil pipelines. Then the morphology and composition of the corrosion scales were characterized by Scanning Electron Microscope（SEM）, Energy Dispersive Spectrometer（EDS） and Xray diffraction（XRD）. The results demonstrated that with the increasing time, the corrosion rate of X65 steel increased firstly and then slowed down to a lower level for long term. While temperature has obvious influence on the corrosion rate of the X65 steel, which presented the top area of the pipeline, where the steel suffered from uniform corrosion with formation of water drop-like corrosion products adhere to the steel surface. At low temperature, the main component of the corrosion products were iron oxide, in the contrast, at high temperature a protective corrosion product com-posed mainly of Fe2 S could form.