液硫池蒸汽伴热管腐蚀分析

Analysis on Steam Companions Corrosion of Sulfur Pit

某化工厂试车过程中液硫池316L蒸汽伴热管及液硫脱气泵夹套筒节发生腐蚀失效,腐蚀均发生在液面附近。通过研究硫黄环境下金属腐蚀机理,对腐蚀伴热管及液硫脱气泵夹套筒节进行宏观检查、能谱分析和金相分析,认为液硫存储过程中有水及空气存在时多种腐蚀协同发生,对不锈钢腐蚀严重。提出了液硫池密封设计和液硫池蒸汽盘管热喷铝等应对措施。

316L steam companions and molten sulfur degasification pump were corroded with striking rate during the test run,and its typical feature is that corrosion happens near the solid-liquid interface.The mechanism of metallic corrosion under sulfur environment was studied.Macro inspection,energy spectrum inspection and metallographic inspection were made on steam companions and molten sulfur degasification pump.It is concluded that multiple types of corrosion co-occur when there is water and air during the storage of liquid sulfur.Preventive measures were proposed,such as sealing design of sulfur pit,thermal spray aluminum of sulfur pit steam coil.