煤气化装置湿洗单元管线腐蚀原因分析及防护  

Corrosion cause analysis and protection of wet cleaning unit pipelines in coal gasification unit

作　　者：李俊权 夏康哲 LI Junquan;XIA Kangzhe(Shenyang Branch of Shenzhen Grusen Technology Co.,Ltd.,Shenyang 110000,China)

机构地区：[1]深圳格鲁森科技有限公司沈阳分公司,辽宁沈阳110000

出　　处：《石油化工腐蚀与防护》2025年第1期59-64,共6页Corrosion & Protection In Petrochemical Industry

摘　　要：某煤化工企业的煤化工气化装置湿洗单元运行10 a的合成气外送管线发生泄漏,通过宏观观察、化学成分分析,硬度检测、金相分析、扫描电镜分析和能谱分析等方法对无缝弯头和直管段连接焊缝开裂泄漏的位置进行综合分析。结果表明:造成开裂的主要原因是管道内部介质具有腐蚀性,长期处于H_(2)CO_(3),H_(2)S和NH 4HS等腐蚀介质的环境中势必会发生腐蚀。在打底焊缝被完全腐蚀后,基材20#钢也开始产生较快的腐蚀;并随着20#钢的腐蚀减薄,在外界应力的作用下产生撕裂而发生泄漏。分析其腐蚀机理后,确定了其腐蚀类型为H_(2)CO_(3),H_(2)S和NH 4HS等腐蚀性介质和外应力双重作用下造成的腐蚀开裂。A leakage occurred in the syngas delivery pipeline of the wet washing unit of a coal gasification unit in in a coal chemical enterprise after 10 years of operation.Through macroscopic observation,chemical composition analysis,hardness testing,metallographic analysis,scanning electron microscopy,energy dispersive spectroscopy and other methods,the location of the cracking and leakage in the connection weld between seamless elbows and straight pipe section was comprehensively analyzed.The results indicated that the main cause of cracking was the corrosive nature of the internal medium of the pipeline,prolonged exposure to corrosive media such as H_(2)CO_(3),H_(2)S,and NH4HS would inevitably lead to corrosion.After the bottoming weld was completely corroded,the base material of 20#steel began to corrode faster;and with the corrosion and thinning of 20#steel,tearing and leakage occurred under external stress.After analyzing its corrosion mechanism,the corrosion type was determined to be corrosion cracking caused by the combined effect of corrosive media such as H_(2)CO_(3),H_(2)S,and NH 4HS,as well as external stress.

关 键 词：煤化工 气化装置 合成气 腐蚀分析 腐蚀防控 

分 类 号：TG1[金属学及工艺—金属学]