硫酸铵循环加热器换热管裂纹产生原因分析

Heat Exchange Tube Crack Reason Analysis of Ammonium Sulfate Circulating Heater

为解决用于加热浓缩硫酸铵母液的循环加热器(不锈钢00Cr17Ni14Mo2换热管)运行3个月后即有管裂纹产生的问题,分别采用光学显微镜和扫描电子显微镜(SEM)观察了裂纹和裂口的微观形貌,X射线能谱分析了裂口表面的化学成分,化学分析技术和金相分析技术分析了管材的化学成分和微观组织。结果表明,该换热管失效的主要原因是Cl-诱导的应力腐蚀开裂,管材的镍含量低于该型号国家标准要求,这必然会降低该不锈钢管材的耐腐蚀性能,从而导致应力腐蚀的发生。

In order to solve the problem of circulation heater(stainless steel 00Cr1714NiMo2 heat exchange tube) pipe crack after running 3 months for heating concentrated ammonium sulfate mother liquor,respectively adopted optical microscope and scanning electron microscope(SEM) to observe the crack and split microstructure,X-ray energy spectrum analyzed the split surface chemical composition,chemical analysis technology and metallographic analysis technology analyzed the pipe chemical composition and microstructure.The results showed that the main reason of heat exchange tube failure was the Cl-induced stress corrosion cracking;the nickel content of the pipe was lower than the model national standard requirement,which reduced the corrosion resistance of stainless steel pipe,thus leading the occurrence of stress corrosion.