镍基单晶合金在900℃硫酸盐熔盐中的热腐蚀行为

摘要

采用X-射线衍射、扫描电镜及能谱等测试手段,研究了一种镍基单晶合金在75％ Na2SO4+25％ K2SO4熔盐中的热腐蚀行为,该熔盐θ为900℃.结果表明,镍基单晶合金热腐蚀严重,出现严重的内硫化和内氧化；外层腐蚀产物由Al2O3 、Cr2O3 Ni2Cr2O4和Co2Cr2O4相组成,内层为Al2O3和CrS；镍基单晶合金表面形成的氧化物发生碱性溶解.%The hot corrosion behaviors of single-crystal Ni-based superalloy were investigated at 900 t in molten sulfate by using SEM,XRD and EDAX. The results showed that the oxidation and sulfuration of alloy were co-occured during the hot corrosion. After corrupted for 30h, the oxide in the outer layer was consist of A12O3 ,Cr2O3 ,Ni2Cr204 and Co2Cr2O4 phases,the oxide in the inner layer was identified as CrS and A12O3 phase. And the dissolution of the oxides on the alloy surface obeys the regularity of alkaline dissolving.