炼厂循环水中不锈钢孔蚀电位的影响因素分析

Analysis of Influencing Factors for Stainless Steel Pitting Corrosion Potential in Refinery Circulating Water

通过对某炼厂生产装置中腐蚀较为严重的不锈钢换热设备进行调研、分析,确定该换热设备腐蚀失效的主要原因是由于循环冷却水垢下腐蚀造成的不锈钢点蚀穿孔。选取几种典型的不锈钢材料,模拟出循环水在换热设备的现场腐蚀环境,利用动电位极化的方法测定及对比其各自的点蚀电位,对上面所选取的材料通过改变腐蚀介质的氯离子浓度、pH值等几个主要影响因素,进而在同条件下对各种因素对不锈钢点蚀的影响进行评价。

Corrosion conditions of the stainless steel heat exchangers in refinery were investigated and analyzed,it was found that key reason of corrosion failure was stainless steel pitting corrosion under scale deposit formed by circulating water.Some typical stainless steel materials were chosen as samples in a series of experiments,their pitting potentials in the simulated corrosion environment were measured and compared by potential dynamic polarization technique.Main factors influencing the pitting including chloride ion concentration,pH value,temperature and so on were discussed.