采用室内试验、现场验证和光谱分析相结合的方法, 以埋地金属管道的外腐蚀成因为切入点, 对北方盐碱土壤环境的腐蚀性进行研究。基于对油田现场土壤的理化试验结果, 确定关键因素, 以9种主要的土壤腐蚀影响因素为变量, 设计9因素3水平的室内腐蚀模拟正交试验。采用20号钢标准腐蚀试片, 进行模拟试验。并对试验结果进行方差分析, 研究了每个因素对土壤腐蚀速率的作用规律, 得到该区域土壤腐蚀因素的重要度次序由大到小为: Na+, 含水率, 温度, Ca2+, 孔隙度, pH, SO42-, HCO3-, Cl-。进一步对腐蚀产物主要成分进行光谱分析, 且与现场埋片腐蚀产物主要成分比较, 结果显示两者主要成分基本一致, 含量有所差别, 一定程度上验证了室内研究结果的可靠性。

Taking external corrosion of pipelines as a research point, laboratory test, site verification and spectral analysis were adopted to investigate the corrosion of saline-alkali soil environment in north China. Orthogonal simulation experiments with 9 factors and 3 levels were designed based on physical and chemical test results of local soil, taking 9 main corrosion factors as variables. Standard corrosion test slices of 20# steel were used to perform kinds of physical and chemical experiments for simulating local soil. Analysis of variance was done to these test results. The affecting rule on corrosion rate of soil was researched, and importance degree order of corrosion factors in this district was obtained, namely, Na+>moisture content>temperature>Ca2+>porosity>pH value>SO42->HCO3->Cl-. Furthermore, the main components of corrosion products were analyzed by X-ray fluorescence and compared with the corrosion products of site test slices. From these results, the main components of both corrosion products were consistent basically, but the contents were a bit different, which validates the reliability of laboratory test results to a certain extent.