分析了余热锅炉中二级过热器管(材质为12CrMoV)的失效原因,结果表明管子的腐蚀和超温可能与失效过程有关,但管子表面腐蚀是二级过热器管失效的主要原因。 利用X-射线衍射、金相、电子探针、红外、差热分析和化学分析等方法,研究了取自现场的腐蚀产物形貌、化学组份和结构。腐蚀产物主要是Fe_2O_3、Fe_2(SO_4)_3和铁的硫化物。因此腐蚀机制可能是Fe_2(SO_4)_3在高温下分解产生高分压的SO_3所引起的硫化和氧化。在分析结果的基础上,提出了解决这种问题的可能途径。
Exploration of the causes of failure of secondary superheater tubes made of 12CrMoV in waste heat boiler has been carried out. The results show that corrosion of tube surface is responsible for the service failure of secondary superheater tubes, though erosion and superheating of tubes may be involved in the failure processes.The structure, chemical composition and morphology of corrosion products on the damaged tube were studied by means of X-ray diffraction metallography, EMPA, IR, DTA and chemical analysis. The corrosion products are mainly composed of Fe_2O_3, Fe_2 (SO_4)_3 and sulfide of iron. Therefore, it is snggested that the mechanism of corrosion is sulfidation and oxidation caused by high partial pressure of SO_3 from decomposition of Fe_2 (SO_4)_3 at elevated temperatures in the system.On the basis of experimental results, possible methods to combat corrosion are proposed.
参考文献
[1] |
- 下载量()
- 访问量()
- 您的评分:
-
10%
-
20%
-
30%
-
40%
-
50%