锅炉受热面复合陶瓷涂层的抗高温腐蚀性能

为寻找燃煤锅炉受热面高温腐蚀问题的解决方法,以过热器材料15CrMoG钢为研究对象,采用料浆法在其表面涂覆复合陶瓷涂层,并对涂层进行500℃高温烧结.分别测试了基材及涂层试样在SO2、H2S和硫酸盐环境下的抗高温腐蚀性能.结果表明:涂层表面不存在较大孔隙、裂纹等缺陷,涂层与基体之间具有较好的结合状态;涂层试样抗SO2、H2S和硫酸盐腐蚀性能优于基材15CrMoG钢,分别为基材的3.3,6.5,1.4倍;涂层经SO2及H2S气体腐蚀后,表面都生成了K2SO4颗粒,但由于涂层内部较为致密,阻止了S元素继续向内部扩散,因此涂层内部几乎没有K2SO4颗粒.

High-Temperature Corrosion Resistance of Composite Ceramic Coating Used in Boiler Heating Surface

In order to improve the high-temperature corrosion of 15CrMoG steel on the coal-fired boiler heating surface,the slurry method was used to prepare a composite ceramic coating for surface protection.After sintered at 500 ℃,large pores,cracks and other defects didn't exist on the surface of the coating.Furthermore,the binding status between substrate and coating was very well.In the simulated SO2,H2 S and sulfate atmosphere at high temperature of 500 ℃,the high-temperature corrosion resistance tests on the coated and uncoated samples were conducted.Results showed that the coated samples with ceramic coating were superior to the uncoated ones in terms of corrosion resistance in simulated SO2,H2S and sulfate atmosphere,which were improved 3.3 times,6.5 times and 1.4 times than that of the uncoated samples,respectively.Under the corrosion atmosphere of SO2 and H2S,K2SO4 particles generated on the coating surfaces,but the denser coating prevented the S element form diffusing into coating's interior part,and therefore,K2SO4 particles were hardly found in the inner part of the coating.