Surface recrystallization and its effect on oxidation of superalloy C263

•Residual strain induced surface recrystallization was observed during oxidation.•Surface recrystallization occurred together with severe internal degradation (oxidation & nitridation).•Grain boundaries of recrystallized grains provide fast paths for outward and inward diffusion. Ni-base superalloy C263 has been oxidized from 700°C to 1100°C in artificial dry air. A continuous Cr rich (Cr, Ti)2O3 layer is formed during oxidation, while the oxidation kinetics deviated from the parabolic kinetics. The oxidation microstructures were different in as-machined and polished samples. Recrystallization below the oxide layer occurred in as-machined samples together with severe internal degradation (internal oxidation and nitridation). Grain boundaries provide paths for fast diffusion of O and N into the substrate and outward diffusion of Ti and Cr. Surface deformation and recrystallization exhibit detrimental effects on the oxidation behavior of C263.