This study investigates the issue of fracture in the quench water tube of a coal hydrogenation gasifier in a petrochemical plant.The analysis was conducted by chemical composition,metallographic structure,microstructure,energy dispersive X-ray spectroscopy(EDS),and X-ray diffraction analysis(XRD).The results indicate that under the action of chloride ions and fluoride ions,pitting corrosion occurs in the quench water tube,and the pits become stress concentration points.In addition,iron sulfide(FeS)reacts with water and O2 in the air to form polythionic acid,which causes polythionic acid stress corrosion cracking in the 304 austenitic stainless steel where pitting occurs.To prevent the recurrence of similar corrosive cracking,material and process optimization recommendations are proposed to effectively reduce the safety production risks of the refining unit,providing valuable information for the long-term safe operation of coal hydrogenation.
关键词
煤制氢/激冷水系统/连多硫酸/应力腐蚀/失效分析
Key words
coal-to-hydrogen/stimulated chilled water system/liandosulfuric acid/stress corrosion/failure analysis
维普
万方数据