干熄焦高压锅炉管道用钢管爆裂原因分析

Analysis of Causes of High-pressure Boiler Pipe Bursting in Coke Dry Quenching

针对干熄焦高压锅炉管管道用钢管爆裂问题,开展了宏观断口、化学成分、显微硬度、金相组织、扫描电镜SEM+EDS等检验分析。结果表明:钢管迎气面外壁暴露在高温循环介质中,发生了高温硫腐蚀,腐蚀产物又受到循环介质的冲刷而脱落,暴露基体,再次腐蚀,如此循环往复,致使锅炉管外壁减薄,当锅炉管的强度不足以承受内部过饱和蒸汽的压力时,锅炉钢管向外爆裂。为避免事故再次发生,提出了改进建议。

For the cracking problem of high pressure boiler tubes in CDQ(Coke dry quenching)in the coking plant,inspection and analysis of macroscopic fracture,chemical composition,microhardness,metallographic structure,scanning electron microscope SEM+EDS,etc.were carried out.In the medium,high-temperature sulfur corrosion occurs,and the corrosion products are scoured by the circulating medium and fall off,exposing the substrate and corroding again.This cycle repeats,resulting in the thinning of the outer wall of the boiler tube;when the strength of the steel tube is not enough to withstand the pressure of the internal supersaturated steam the boiler pipe burst outwards.