Effects of electron beam smelting on removal of inclusions in nickel-based superalloys

Abstract

Electron beam smelting has been applied in refining nickel-based superalloys, which has been proved to be an effective method for removing inclusions. The inclusions are aggregated at the circular region (last solidified region) of the ingot surface periphery where the electron beam finally stayed by induced directional solidification after electron beam smelting. The relationship between the cleanness of nickel-based superalloys and the refining times was investigated. Based on the different refining times, the removal efficiency of inclusions was also discussed and the corresponding experiment was carried out to be compared. The results show that the area of the last solidified region on ingot surface decreases with the increasing of the refining times. The optimal refining time of nickel-based superalloys is considered in order to obtain a relatively high removal efficiency of inclusion and a low mass loss rate.