Corrosion Behavior of GH3535 Alloy Induced by Selenium

Corrosion behavior of a Ni-16Mo-7Cr base superalloy was systematically investigated under a selenium (Se) atmosphere at 700 degrees C. It shows that Se can react with the alloy elements such as Ni, Mo, Cr et al. to form a reaction layer at the surface of alloy, which is mainly composed of Ni2Se3, MoSe2, and Cr3Se4. The tensile properties of the alloy are not greatly affected by changes of Se content. The slight decrease in the tensile strength is attributed to the formation of the reaction layer, which leads to the decrease in the effective undertaking area of the alloy. No intergranular diffusion characteristic of Se elements was observed, and the Se effect of embrittlement on grain boundaries is weaker than that of tellurium (Te).