In order to figure out the effect of shot peening on steam oxidation behavior of Inconel740 H

the Inconel740 H with and without shot peening was oxidized in pure steam at 700 ℃ and 750 ℃for exposure time up to 1 000 h.The mass gain of samples was measured by electronic balance

the oxide films were analyzed through XRD and SEM.The results show that the Inconel740 H with different surface states were oxidized approximately following aparabolic law.The oxidation rate raised up with the water vapor temperature

and more internal oxides were observed at higher temperatures.However

shot peening accelerated the transformation of oxide morphologies.A dense and flat oxide layer without raised oxides on grain boundary was observed on the Inconel740 H with shot peening.The inner diffusion of oxygen was accelerated by shot peening

leading to an increase in the oxidation rate.The research results can provide theoretical basis for pretreatment of the Inconel740 Hsteel.