炉烟处理灰水装置管道的失效分析

Failure analysis on ash water equipment piping for cooling water flue gas treatment

采用光谱分析、金相检验、扫描电镜、电子能谱分析等技术 ,对炉烟处理灰水装置中失效管道材料进行了化学成分、显微形貌、金相组织等综合检测分析。结果表明烟气管道腐蚀区域呈现典型的均匀腐蚀 ,喷射管、布气管腐蚀区域呈现典型的点腐蚀形貌 ,腐蚀产物中 S、O、Cl等元素大量超标。表明混合气中含有的 SO2 、CO2 酸性气体和海水中的 Cl- 离子对管道内表面腐蚀起主要作用 ,而混合气中灰颗粒和泥沙对管道内壁的冲刷与磨损是造成管道损伤的另一重要因素。还进一步讨论了实际工况下管道的腐蚀机理 ,并提出相应的预防措施。

Using such techniques of optical spectrum analysis,metallography examination,scanning electron microscope and electron energy spectrum analysis the comprehensive inspection analysis of chemical composition,microstructure and metallography morphology were carried out on the failure piping sample.Experimental results show that the corrosion area of the piping shows typical uniform corrosion.The corrosion area of ejector pipe and gas distribution pipe represents a typical pitting corrosion and the contents of S,O and Cl contained in the corrosion product are seriously beyond the standard.The result proves that SO_2 and CO_2 in the mixed gas and Cl^- in sea water play a role in the corrosion of the inner wall of the piping and ash particles and mud sand in the mixed gas are another important factor for the piping damage.The corrosion mechanism of the piping under service condition was discussed and the corresponding protective measurement was put forward.