本研究主要在探討兩種鎳基超合金Inconel-625(In-625)和Hastelloy X(Has-X)在750~1050℃乾空氣下之氧化行為。整體而言,兩種合金之氧化動力學皆遵守二段式拋物線律,顯示固態擴散為合金氧化主要機制。經比較穩定增重區之氧化速率常數(K(下標 p))得知,兩種鎳基超合金的氧化速率相近,由顯微結構分析得知,合金氧化後的生成物以Cr2O3為主,並在氧化層表面有少量的MnCr2O4摻雜其上。
The oxidation behavior of two Ni-based superalloys, Inconel-625 (In-625) and Hastelloy X (Has-X) was studied at 750~1050℃ in dry air. The oxidation kinetics of both alloys followed a two-stage parabolic-rate law, indicating that diffusion is the rate-controlling step during oxidation. The steady-state rate constants (k(subscript p) values) of these two alloys were nearly identical. The scales formed on the two alloys were composed of a heterophasic mixture of mostly Cr2O3 and minor MnCr2O4.