Oxidation Behavior of GH3535 Superalloy at 700℃ and 900℃

The isothermal and cyclic oxidation behavior of GH3535 superalloy in air at 700 oC and900oC were investigated by using TGA method. The results show that GH3535 alloy has a good oxidation resistance to isothermal oxidation at 700℃and 900℃. But the alloy shows a worse resistance to cyclic oxidization, especially when cyclic oxidation at 900 oC the alloy suffered from accelerated oxidation with rather severe spallation of oxide scales. The X-ray and EDS analysis show that the formed oxide scale consists mainly of Cr2O3, Ni Mn2O4 and Fe Cr2O4 during isothermal oxidation. However, oxide products such as Mo O2, Ni Fe2O4, Ni Cr2O4, Ni Mn2O4, and Ni Mo O4 can be detected after cyclic oxidation. The oxidation resistance of the alloy decrease noticeably because of the cracking and spallation of the protective oxide scale as well as the continuous participant of Mo in the oxidation process.