9Cr18合金的燃气热腐蚀行为

Gas Hot Corrosion Behaviors of 9Cr18 Alloy

利用燃气热腐蚀试验、扫描电镜观察等手段,研究了9Cr18合金在高温燃气中的热腐蚀行为。结果表明:该合金燃气热腐蚀产物可分为内、外两层,且内、外两层之间存在较大的裂纹;外层腐蚀产物含有较多铬的氧化物,层内存在较多的横向裂纹;内层腐蚀产物铬的氧化物含量较低,且疏松多孔;合金表面和晶界发现有硫化物,合金存在明显的晶间腐蚀倾向;腐蚀初期腐蚀增重和腐蚀速率较快,随着时间的延长腐蚀增重和腐蚀速率趋于平缓。

The gas hot corrosion behaviors of 9Cr18 alloy in high-temperature gas were studied by hot gas corrosion test and SEM observing.The results show that the gas hot corrosion products of the alloy could be divided into two layers,and there were large cracks between the two layers.The outside layer contained more chromium oxide and transversal cracks,and the internal layer contained less chromium oxide and was loose and porous.Sulfur compounds were found on the alloy surface and grain boundaries,and the alloy had an obvious tendency to intergranular corrosion.The corrosion mass gain per unit surface area and corrosion rate were rather fast in the early stage,and then tended to be slow and steady.