【作者】 臧启山； 姚戈； 苏会和；

【Author】 ZANG Qi-shan,YAO Ge,SU Hui-he (CFA of Institute of Metal Research,Chinese Academia of Sciences,Shenyang 110016,China)

【机构】 中国科学院金属研究所失效分析中心；

【摘要】 某换热器中多根不锈钢管发生开裂。宏观观察看到管材表面有大量的腐蚀坑,裂纹分叉;扫描电镜观察表明裂纹起始于腐蚀坑,断口高低不平,内外壁均有多个裂纹源,呈穿晶解理断裂形貌;腐蚀产物的EDS分析结果表明,腐蚀坑和锈蚀表面均含有相当高的硫和氯元素;此外钢管还承受工作应力和装配应力。综合分析表明换热器不锈钢管开裂属于应力腐蚀开裂。更多还原

【Abstract】 Some stainless tubes in a heat exchanger cracked during operation.Many small pits,branched cracks were seen on the failed tubes surfaces.SEM observation show that the cracks initiated at the pits,and both from inner and outside surface of each tube.The fracture surface was rough,and exhibited cleavage fracture morphology.EDS analysis at pits and tube surface show that high contents of sulphide and chloride existed in the corrosion products.Applied pressure stress and assembly stress were also exited.Therefore it was concluded that the tubes failure was attributed to the stress corrosion.更多还原