Study of cyclic oxidation and hot corrosion of 310 SS under the environmental impurities of Na2SO4+V2O5 at different temperatures

Abstract

The high temperature behaviour of 310 stainless steel has been studied at 750, 900, 950 °C in air and 2 mg per cm2 mixtures of molten salt (NA2SO4 60%+V2O5) environment. The corrosion behaviour and morphological development were investigated by weight change kinetics, characterization techniques, depths of attack, metal losses, and elemental analysis. The results of 310SS deposited with salt mixtures show that weight change kinetics in simple oxidation reveals a steady-state parabolic rate law after initial cyclic heating, while the kinetics with salt and vanadium oxide display multi-stage loss of material. The characterization results show that there is formation of oxides on the surface of oxidized sample and then the hot corroded samples show formation of respective metal sulphides which is the reason for spallation of material so that again internal layer is exposed to environment.