The Effect of Alloying Elements on the High Temperature Oxidation of Solid-Solution Strengthened Ni-base Superalloys

摘要

The effect of major and minor alloying elements on the cyclic oxidation resistance of solid-solution strengthened Ni-base superalloys was studied. Ni-base superalloys with various Cr, W, Mo, Mn, Si, Al, La, C and B contents were produced. The samples were exposed at 1150°C in ambient air for 15 min. and then cooled down in room temperature for 5 min. cyclically. Weight changes after the cyclic oxidation were analyzed as a function of alloying contents. The simple statistical spalling model was used in some cases. With the simple statistical spalling model, the effect of alloying elements on the adhesion of oxide scale and on the oxidation rate can be analyzed respectively. The addition of W and Mo was beneficial to the oxidation resistance only in alloys with 18 wt.% Cr. Al reduced oxidation rate and improved adhesion of scale, while Si only reduced oxidation rate. The database produced by this study can be employed for alloy development tools such as neural network methods to develop Ni-base superalloys with improved oxidation resistance.