【摘要】 高压蒸发器管发生泄露。采用化学成分、金相、拉伸与能谱等方法对其材质进行鉴定,结果表明材质不是蒸发器管腐蚀泄露的原因。腐蚀形貌与射线检查结果表明:泄漏点主要发生在焊缝附近的热影响区,通过现场工况调查并结合未泄露管化学清洗前后形貌、酸洗模拟试验与内壁沉积物分析,表明内壁腐蚀特征与停用时积水情况有明显对应关系,酸洗过程不会对金属基体造成明显腐蚀损伤,腐蚀主要发生在化学清洗前;采用停用腐蚀模拟试验对现场工况进行还原,其结果与现场实际管子的腐蚀特征基本一致。因此,基建期间部分管子内局部有积水和污物导致发生停用氧腐蚀是本次蒸发器管泄露的主要原因。更多还原

【Abstract】 In order to find out the leakage cause of a SA210( A1) high-pressure evaporator tube,chemical composition analysis,tensile testing,metallographic examination and energy spectrum analysis were carried out. The results show that the leakage of the high-pressure evaporator tube was not caused by material problem. The corrosion morphology and X-ray inspection results show that the leakage occurred in the vicinity of the weld heat affected zone. Through the investigation on on-site conditions and morphology analysis on unleaked tube before and after chemical cleaning,pickling simulation test and analysis on sediment at the inner wall,it is found that there is a corresponding relationship between the corrosion characteristics of the inner wall and accumulated water during the period out of service. Picking process didn ’t cause significant corrosion to the substrate and corrosion occurred mainly before chemical cleaning. The on-site conditions reoccurred by deactivation corrosion simulation test.The results show that the corrosion characteristics are consistent with those of the actual tube on site. Therefore,the water and dirt in part of the tube during construction led to the deactivation oxygen corrosion,which is the main reason for the leakage of the evaporator tube.更多还原