中文摘要：

采用粉末包埋法在耐热钢T91表面制备渗铝涂层并研究了T91、S304以及渗铝涂层在600℃和650℃下典型燃煤气氛4%HCl＋2%SO2＋94%O2中的腐蚀行为。结果显示耐热钢T91和S304合金在600℃和650℃下均受到了气氛中S和Cl的加速腐蚀。在2种温度下,低Cr含量的T91腐蚀时其表面均生成了外层富Fe内层富Cr的不具有保护性的FeCr混合氧化物层,腐蚀增重很大;Ni和Cr含量较高的S304由于硫化氧化和活化氧化机制使得表面腐蚀产物脱落严重,特别是在较高的温度650℃腐蚀时。当T91表面采用粉末包埋法渗铝后能显著降低在这2种温度下的腐蚀增重,原因是高温腐蚀后在涂层表面生成了一层连续、致密、与涂层结合良好的保护性氧化膜Al2O3,这层氧化膜能有效的防止S和Cl的渗透作用,因而对基体合金起到了良好的防护作用。

英文摘要：

In this article,powder embedding method was employed to deposit aluminized coating on heat-resisting steel T91 alloy,and then the high temperature corrosion behaviors of T91,S304 and the aluminized coating were investigated at 600℃ and 650℃in a 4%HCl＋2%SO2＋94%O2 mixed atmosphere based on typical coal-combustion surroundings.The results show that the corrosion behaviors of T91 and S304are accelerated by S and Cl at the two temperatures.After 300 h corrosion,the surface of T91,which contain lower Cr,forms a non-protective thick mixed FeCr oxides layer.The metal sulfates are found at interface of alloy/corrosion products,and the surface corrosion products formed by higher Ni and Cr on S304 are easily to exfoliate,especially at higher temperature 650℃.However,a continuous,compact,and protective Al2O3 layer is formed on the aluminized coating to prohibit quick corrosion on T91 surface in S and Cl mixed atmosphere at both two temperature.