254SMO超级奥氏体不锈钢换热板片的腐蚀失效原因

Corrosion Failure Reason of 254SMO Super Austenitic Stainless Steel Heat Exchange Plat

某煤化工厂用于废水处理项目的换热板片(材质254SMO)使用约半年就发生了腐蚀失效。对该厂废水水质进行了分析,并对该换热板片进行了宏观检查、成分分析、金相分析、扫描电镜分析和能谱分析。结果表明:废水介质的含盐量高、污染物种类繁多、介质温度较高,形成了特殊腐蚀环境,且换热板片的密封圈会形成缝隙结构,由换热板片所处的介质环境和自身结构导致该板片发生点蚀和缝隙腐蚀,随着腐蚀的进行,最终造成254SMO超级奥氏体不锈钢换热板片失效泄漏。建议通过添加缓蚀剂和升级换热板材质等加强防护。

The heat exchange plate(steel 254SMO)used in a wastewater treatment project at a certain coal chemical plant had undergone corrosion failure after about half a year of service.The wastewater quality of the factory was analyzed,and the heat exchange plate was subjected to macroscopic examination,composition analysis,metallographic analysis,scanning electron microscopy analysis,and energy spectrum analysis.The results show that the wastewater medium had a high salt content,a wide variety of pollutants,and a high medium temperature,forming a special corrosive environment.The sealing ring of the heat exchange plate would form a gap structure,which was caused by the medium environment and its own structure of the heat exchange plate.As the corrosion progresses,it ultimately led to the failure and leakage of the 254SMO super austenitic stainless steel heat exchange plate.It was recommended to strengthen the protection of the system by adding corrosion inhibitors and upgrading the material of the heat exchange plate.