某换热器波纹板开裂原因分析

某公司生产的换热器波纹板开裂后发生串液现象,采用化学成分分析、金相检验、扫描电镜分析等方法,对波纹板开裂原因进行了分析。结果表明:该换热器在运行过程中不规范停车,停车后未及时排空液态介质;同时波纹板材料中镍、钼元素含量低于标准要求值,热侧介质自来水中Cl^-含量远超出技术要求,这些因素使得密封垫圈和波纹板交界处发生孔腐蚀,腐蚀孔连接形成裂纹,最终导致波纹板开裂失效。

Cause Analysis on Cracking of Corrugated Plates in a Heat Exchanger

The corrugated plates of a heat exchanger produced by a company cracked which resulted in liquidcrossing phenomenon happening.Chemical composition analysis,metallographic examination and scanning electron microscopic analysis were used to analyze the causes of cracking of the corrugated plates.The results show that the heat exchanger was not stopped according to the regulation during operation and liquid medium was not emptied in time after stopping.At the same time,the content of nickel and molybdenum elements in the corrugated plate material was lower than the standard requirement,and the content of Cl^- in hot side medium running water far exceeded the technical requirement.These factors caused hole corrosion happened at the interface between the junction of gasket and the corrugated plate,and cracks formed by connection of corrosion holes,which eventually led to cracking failure of the corrugated plates.