高酸原油加工中常用材质的耐腐蚀性能

Anti-corrosion Properties of Common Materials in Processing High Acid Crude Oil

采用定点测厚、氢通量等腐蚀检测技术在2008--2010年对中石化四套加工高酸原油常减压装置进行了两年半的腐蚀监测，并将检测结果与AP1581中数据进行了对比。结果表明，20#材质在220℃以上即腐蚀明显；焦化装置高温进料线多为Cr5Mo，部分管道腐蚀减薄明显；304／321材质在288℃以下腐蚀轻微，但用于高温、高流速的转油线则腐蚀严重；316L材质抗高酸油腐蚀性能良好，即使是转油线也基本腐蚀轻微，腐蚀速率约0．1mm／a，少部分监测点腐蚀速率为0．1～0．2mm／a。

Corrosion detection technologies such as fixed thickness measurement and hydrogen flux testing were used to monitor the corrosion of 4 atmospheric and racuum distiuation units from 2008 to 2010 for about two and a half years. The monitoring results were compared with the database of API 581. The results showed that material 20# had obvious corrosion when the temperature was over 220℃. In the high temperature feed line of coking unit made of material Cr5Mo mainly, some of the pipelines were thinned by corrosion significantly. Corrosion of pipelines with material 304/321 was slight when the temperature was below 288℃. Serious corrosion occurred on material 304/321 when used for higher temperature and high fluid velocity transfer line. Material 316L had good anti-corrosion capability in processing high acid crude oil, even the corrosion of transfer line was slight. The corrosion rate of transfer lines with material 316L was about 0. 1 mm·a^-1, and small part of which was 0. 1-0.2 mm·a^-1.