材料期刊网

研究了我国开发的Zr-Sn-Nb合金(N18和N36)在360℃、18.6 MPa含LiOH高温高压水，400℃和500℃、10.3 MPa过热蒸汽中的腐蚀行为.结果表明，两种合 金试样在500℃腐蚀500 h未出现疖状腐蚀，而Zr-4合金在4 h就出现疖状腐蚀；在400℃腐蚀 245 d后，N18试样的增重低于Zr-4，而N36的增重高于Zr-4；在360℃含LiOH的高温高压 水中腐蚀300 d，两种合金试样的增重只有Zr-4的16%～25%.N18合金不仅在高温高压水中而 且在过热蒸汽中都具有优良的抗腐蚀性能.在Zr-Sn系合金中加入适量的Nb，一部分固溶在α -Zr中可以抵抗C、N等杂质对腐蚀性能的有害影响，另一部分形成第二相均匀弥散分布在合 金中可明显降低合金在高温水和过热蒸汽(500℃)中的氧化速率.氧化膜/金属界面处的氧化 膜生长存在不均匀性，转折后氧化膜的不均匀生长更明显.

The corrosion behaviors of Zr-Sn-Nb alloy (N18, N36) developed in China have been studied by out-of-pile autoclave in 360℃ wate r with 70 μg/g Li,in 400℃ and 500℃ high pressure steam.The results show that the nodular corrosion for two kinds of alloys did not occur after 500h,and Zr-4 alloy did after 4h in high-pressure oxygen at 500℃;that the weight gain of N18 samples is lower than Zr-4,and of N36 is higher than Zr-4 after 245 days in 400 ℃ high pressure steam;that the weight gain for two kinds of alloys samples is o nly 16%-25% that of Zr-4 after 300 days in 360℃ water with 70 μg/g Li.N18 allo y possesse s good corrosion resistance in both high temperature water and high pressure ste am.Addition of alloying element Nb in Zr-Sn binary system,on the one hand,solid solution of Nb in α-Zr can resist the detrimental effect of C,N impurities on c orrosion behavior,on the another hand,the formation of α-Nb second phase partic les and their uniform distribution in alloy can reduce greatly the oxidation rat io in high temperature water and high pressure steam.The nonuniform growth of o xide film occurs at the oxide film/metal interface,and that of oxide film become s more distinct after oxidant transition.