锅炉过热器无缝钢管渗漏原因  

Causes of seamless steel pipe leakage of boiler superheater

作　　者：刘连花 杨宏坤 杨勇 谢咏馨 卢凤池 黄玉玲 魏正龙 LIU Lianhua;YANG Hongkun;YANG Yong;XIE Yongxin;LU Fengchi;HUANG Yuling;WEI Zhenglong(The Center for Industrial Analysis and Testing,Guangdong Academy of Sciences,Guangzhou 510650,China;Guangzhou Shipyard International Co.,Ltd.(Intelligent Manufacturing Research Institute),Guangzhou 511462,China)

机构地区：[1]广东省科学院工业分析检测中心,广州510650 [2]广船国际有限公司工法研究所(智能制造研究所),广州511462

出　　处：《理化检验(物理分册)》2025年第3期62-66,76,共6页Physical Testing and Chemical Analysis(Part A:Physical Testing)

基　　金：国家自然科学青年基金项目(52301039)。

摘　　要：某锅炉过热器无缝钢管使用后出现渗漏现象,采用宏观观察、化学成分分析、金相检验、硬度测试、扫描电镜与能谱分析、X射线衍射分析等方法对钢管的渗漏原因进行分析。结果表明:锅炉过热器钢管的化学成分、显微组织和硬度均符合标准要求,但由于过热器长期在高温高压条件下运行,含Cr元素的碳化物沿晶界析出,严重削弱了晶界的耐腐蚀性能,且管内表面受腐蚀性介质腐蚀,管外表面受腐蚀性高温烟气冲刷,导致管内外表面出现应力腐蚀开裂,裂纹不断扩展,最终钢管发生渗漏现象。Leakage occurred in the seamless steel pipe of a boiler superheater after use.The leakage causes of the steel pipe were analyzed by means of macroscopic observation,chemical composition analysis,metallographic examination,hardness test,scanning electron microscope and energy spectrum analysis,X-ray diffraction analysis and other methods.The results show that the chemical composition,microstructure and hardness of the boiler superheater steel pipe met the standard requirements.However,due to the long-term operation of the superheater under high temperature and high pressure conditions,the carbides containing Cr elements precipitated along the grain boundary,which seriously weakened the corrosion resistance of the grain boundary.In addition,the inner surface of the tube was corroded by corrosive media,and the outer surface of the tube was scoured by corrosive high-temperature flue gas,resulting in stress corrosion cracking on the inner and outer surfaces of the pipe,and the cracks continued to expand.Finally,the leakage of the steel pipe occurred.

关 键 词：无缝钢管 耐腐蚀 渗漏 碳化物 应力腐蚀开裂 

分 类 号：TB31[一般工业技术—材料科学与工程] TG174[金属学及工艺—金属表面处理]