某循环油蒸汽发生器管束发生断裂。通过现场检查,返厂检查,及取样检查(化学成分、显微组织、裂纹形貌、力学性能、断口形貌及表面垢物成分)对管束的失效原因进行了分析。结果表明:断裂失效是介质在管孔缝隙处蒸发浓缩后产生的应力腐蚀所致。最后,根据管束开裂失效的原因,从循环油蒸汽发生器管束的设计选材、制造、水质保障等方面提出了相应的建议。

The tube bundle of a circulating oil steam generator fractured. The failure causes of the tube bundle were analyzed by on-site inspection, return inspection and sampling inspection (chemical composition, microstructure, crack morphology, mechanical properties, fracture morphology and surface scale composition). The results show that the fracture failure of the tube bundle was caused by stress corrosion because of evaporation and concentration of the medium in the gap of the tube hole. Finally, according to the reasons for the failure of tube bundle cracking, some suggestions were proposed on design, material selection, manufacture and water quality assurance of the circulating oil steam generator tube bundle.