环烷酸腐蚀研究与选材探讨

Study on Naphthenic Acid Corrosion and Material Selection

采用静态挂片失重法分别对蓬莱19-3、北疆及旅大-10三种高酸原油的环烷酸腐蚀进行实验室模拟腐蚀评估。结合换剂检修期间的腐蚀调查结果分析,对环烷酸腐蚀环境的选材进行了探讨。挂片失重结果表明正确选择材料等级能有效防止环烷酸的腐蚀,在常减压装置腐蚀拐点温度以上及高流速部位选择Mo质量分数为不小于2.5%的316L不锈钢能有效阻止原油中的环烷酸腐蚀;根据对环烷酸腐蚀环境选材的结果提出了在选材时应该考虑在环烷酸腐蚀的温度范围内设重点防腐起始点。

The naphthenic acid corrosion of 3 high - TAN crude oils i.e. Penglai - 13 crude, Beijiang crude and Luda - 10 crude was studied by weight - loss coupon test and laboratory simulation corrosion test. The material selection for naphthenic acid corrosion environment was analyzed according to the results of corrosion investigation during the maintenance and replacement of chemical agent. The results of weight - loss coupon tests show that the correct selection of materials can effectively protect naphthenic corrosion. For the high velocity service and service with temperature higher than inflection point temperature in atmosphericand vacuum distillation unit, the 316L stainless steel with Mo no lower than 2.5 % should be selected, which could effectively prevent naphthenic corrosion of crude oil. It is also proposed to set initial corrosion temperature in the corrosion temperature range of the naphthenic acid for material selection.