摘要
对某锅炉水冷壁管内壁腐蚀原因进行分析。根据对水冷壁内壁腐蚀产物进行化学元素分析、金相检测、SEM扫描电镜及EDS分析和XRD分析结果 ,认为腐蚀原因是凝汽器铜管发生腐蚀泄漏,使炉水质量变差。Cu2+在水冷壁内壁表面上沉积,对水冷壁管内壁保护膜产生破坏作用,导致水冷壁管内壁出现点蚀。而炉水处理过程中磷酸盐的加入,促进了Cu等金属元素在内壁的沉积,加剧了腐蚀。水冷壁内壁的腐蚀产物不断生成并附着在内壁上,既造成管壁持续减薄,又影响了管子的传热效果,使管子在运行中一直处于超温状态,组织逐渐老化。管壁的减薄和材质的老化共同导致该管子无法承受内部介质压力而发生泄漏。为防止同类事故再次出现,制定了具体的处理措施。
The causes of severe corrosion of internal corrosion and leakage of the water wall tube were analyzed. A fixed-scheme was formulated. According to chemical element analysis, metallographic examination, SEM, EDS and XRD analysis results of corrosion product of inner of water wall tube, the main reason was the condenser copper tube corrosion,which can lead to the failure of the condensation-retained abnormality. Cu2＋deposited on the inner wall of the water wall surface has damaging effects on the tube protective film. As the runtime went on, pitting corrosion occured. The added phosphate promote the deposition of metallic elements such as Cu on the tube inner surface and corrosion. The corrosion products generate continuously and attached inside the walls, which made the tube thinning and affected the heat transfer effect. The tube was in a state of overheat in the runtime and the microstructure gradually age. Tube wall thinning and material aging together lead to the internal medium pressure which cannot afford and the leaking pipe. To prevent the similar accident,the concrete treatment measures were put forward.
出处
《热加工工艺》
CSCD
北大核心
2014年第22期211-214,共4页
Hot Working Technology
关键词
腐蚀
水冷壁
凝汽器
corrosion
water wall tube
condenser
