N80钢CO2腐蚀产物膜在水/砂两相流介质中的磨损性能

采用高温高压静态釜对N80油套钢在CO2中的腐蚀行为进行了模拟腐蚀试验;利用自制的磨损试验装置对比分析了腐蚀产物膜在水/砂两相介质中的磨损性能同成膜温度、CO2压力、流速及砂粒度之间的关系;用扫描电子显微镜分析了N80钢表面CO2腐蚀产物膜及其磨损表面形貌,用表面形貌仪测定了磨损试验前钢表面CO2腐蚀产物膜的粗糙度.结果表明:成膜温度和压力对钢表面腐蚀产物膜的表面粗糙度具有显著影响;N80钢表面CO2腐蚀产物膜磨损表面形貌沿深度方向存在差异,对应的抗磨性能亦有所不同;两相介质中的砂粒度越大或流体相对流速越大,则腐蚀膜的磨损越剧烈.

Wear Behavior of CO2 Corrosion Scales on Well Tube Steel N80 in Water-Sand Two-Phase Fluid Medium

An autoclave was used to simulate the corrosion behavior of N80 steel in CO_2 atmosphere at elevated temperature and pressure. The wear behavior of the resulting CO_2 corroded product scales on the N80 steel in a water-sand two-phase fluid medium was examined on a test rig designed in our lab. The correlations among the wear behavior of the scales and the temperature and CO_2 pressure at which the scales were formed, and the flowing velocity and sand granularity of the two-phase fluid medium, were investigated. Thus the surface roughness of the original scales was determined using a profilometer, while the worn surfaces and cross-sections of the scale were observed using a scanning electron microscope. Results indicated that the surface roughness of the original corrosion product scales was dependent on the temperature and CO_2 pressure for the simulating corrosion tests, and the morphologies of the worn surfaces and cross-sections of the scales varied with varying wear depths, which corresponded to the differences in the microstructures, especially the grain granularity and compactness of the scales. Moreover, the erosion-wear behavior of the scales was also dependent on the flowing velocity and sand granularity of the two-phase fluid.