Influence of grain size on tellurium corrosion behaviors of GH3535 alloy

•Triple-layer scales occur in both the fine-grained and coarse-grained specimens.•Fine-grained specimens possess the thicker outer layer and the discrete inner layer.•Fine-grained specimens possess the shallower Te permeation along grain boundaries.•Fine-grained specimens possess the shallower Cr3Te4 existence along grain boundaries.•Fine-grained specimens provide more paths for the outward diffusion of Cr.