1000MW超临界锅炉低再管外壁腐蚀膜微观分析

为了保障超临界锅炉的长期安全稳定运行和降低检修成本,文中借助于OM、SEM、EDS、XRD等对1 000 MW超临界锅炉低再管表面腐蚀产物的形貌、元素组成及分布、物相构成等进行了分析。试验结果表明:1 000 MW超临界锅炉低再管垂直段表面的腐蚀层为两层,内层由Fe_2O_3、Fe_3O_4和少量Cr的氧化物构成,外层由Si、Al和Fe的氧化物构成。同时该锅炉的长时间超温运行加大了腐蚀膜开裂剥落的几率,进而造成了管子的腐蚀损伤,增加了爆管的可能性。

Microanalysis on Ektexine Corrosion Film of Low-temperature Reheater Tube for 1000 MW Supercritical Boiler

In order to ensure supercritical boiler operating safely and stably long-term,reduce the repair cost, an ektexine corrosion film of low-temperature reheater tube for 1000 MW supercritical boiler and its morphology, element compositions and distribution, phase compositions were analyzed by OM,SEM,EDS and XRD.The results show that two layers compose an ektexine corrosion film of low-temperature reheater tube for 1000 MW supercritical boiler.Inner composite layer is made up of Fe2O3,Fe3O4 and small amount of Cr-oxide, and outer with Si-oxide, Al-oxide and Fe-oxide.Meanwhile, long time operating under high temperature boosts peeling and cracking rate of corrosion film to cause the corrosion damage of tubes and increase the odds of tube explosion.