Correlation between microstructure evolution and creep of alloy 263

Abstract

This study discusses the temperature dependence of deformation mechanisms and microstructure evolution during creep. Alloy 263 was investigated for creep under various conditions of applied stress and temperature until fracture. The crept microstructure was analyzed using electron microscopy. The analysis shows the phase reaction of MC + gamma -> M23C6 (gamma', eta) in creep condition takes place. Moreover, the precipitation of eta, which has slower precipitation kinetics than gamma', was promoted by creep. Additionally, the interaction between gamma' and dislocations changed from shearing to by-passing with the increase of temperature because critical shear stress of each deformation mechanisms is dependent on temperature.