针对某高含硫净化厂硫磺回收装置, 采用现场挂片方法研究了20G、16MnR、304L以及316L钢在装置中的耐腐蚀性能, 同时提出了相应的预防措施。结果表明: 304L和316L奥氏体不锈钢的耐腐蚀性能良好, 具有更好的适用性; 20G和16MnR钢存在严重的(亚)硫酸露点腐蚀、H2S-H2O腐蚀和高温硫化腐蚀现象, 腐蚀类型主要为均匀腐蚀; 过程气温度过高或过低以及水含量、氧含量的增加都会加快20G钢和16MnR钢的腐蚀速率; 液硫中20G钢和16Mn钢的腐蚀产物主要为铁的硫化物和氧化物; 气相腐蚀介质中20G钢和16MnR钢的腐蚀产物主要为FeSO4和FeSO3, 另外还有少量铁的氧化物和硫化物; 建议对易发生腐蚀的设备管线设置腐蚀监测点进行长期腐蚀监测, 并定期进行维护和保养。

For the sulfur recovery unit in a high sulfur purification plant, liquid sulfur corrosion coupon testing was performed to study the corrosion resistance of 20G, 16MnR, 304L and 316L steels in sulfur recovery unit, and corresponding preventive measures were put forward. The results show that 304L and 316L austenitic stainless steels had good corrosion resistance in liquid sulfur, while 20G and 16MnR steels suffered serious H2SO3/H2SO4 dew point corrosion, H2O-H2S corrosion and high-temperature sulfidation corrosion, and the corrosion mode was mainly uniform corrosion. The corrosion rate of 20G steel and 16MnR steel increased when the process temperature was very high or very low and when the water content and oxygen content increased. The corrosion products on 20G steel and 16Mn steel were mainly iron sulfide and oxide. In corrosive vapor, the corrosion products on 20G steel and 16MnR steel were mainly FeSO4 and FeSO3, in addition, a small amount of iron sulfide and oxide were found. Based on the results above, setting corrosion monitoring points and monitoring these points for a long time were suggested. What′s more, it is necessary to keep suitable repairing and maintenance for the easily corrosive positions.