稀土元素微合金化提高HP40合金高温抗氧化能力研究

Study on High Temperature Oxidation Resistance of RE Modified HP40 Superalloy

摘要:

通过扫描电子显微镜（SEM）、X光电子能谱仪（EDS）、X射线衍射仪（XRD）等手段分析了稀土元素的添加对HP40合金抗高温氧化能力的影响。1100 ℃氧化120 h后增重最小的试样（HP40+Y）单位面积增重约为16.24 g/m2，远低于未添加稀土元素试样在相同条件下的氧化增重（36.45 g/m2），表明稀土元素的添加有效提高了合金的抗氧化能力。对试样氧化膜内部组成结构的分析发现，添加稀土元素后氧化膜表面存在一层完整的尖晶石氧化物，而未添加稀土元素的试样氧化后表层尖晶石不连续。另外，稀土元素促进了硅的内氧化，这种内氧化产物钉扎基体，增大了氧化膜与基体的接触面积，改善了氧化膜与基体界面的结合强度。

Abstract:

The effect of RE addition on the high temperature oxidation behavior of HP40 alloy was studied by SEM, EDS and XRD. The smallest mass gain of the sample with RE addition (Y addition) after 120 h oxidation at 1100 oC is 16.24 g/m2, much lower than that of the sample without RE addition (36.45 g/m2) oxidized under the same condition. The results indicate that RE can improve the high temperature oxidation resistance of HP40 alloy effectively. By analyzing the structure of the oxide scale, it can be inferred that RE addition helps to keep a continuous spinel outer layer while such layer on the sample without RE addition is discontinuous. Moreover, RE addition facilitates the formation of internal oxide, which penetrates into the matrix and increases the contact area with the matrix. As a result, it improves the scale adherence and inhibits the spallation.