Wetting phase transition of grain boundaries and material performance of novel Inconel 718

•Inconel 718 GBs at 1200 °C are completely wetted as it was covered by secondary phases.•800 °C and 1200 °C compressed the wetted GBs and led to the improvement in ductility.•Sub-micrometric voids were observed at 1200 °C which cause to decrease the tensile strength. In this work grain boundary (GB) wetting phase transition of Inconel 718 is investigated. 15% GBs are totally wetted when the temperature is raised to 1200 °C. GB was characterized using Electron Backscattering Diffraction (EBSD). The experimental results revealed that the wetted GB fraction increases to 80% at 1200 °C and no evidence of transformation beyond this limit. The GBs clearly show that the wetting state and the cooling rate at about 1200 °C are almost similar to that of quenching. Under ambient condition, it exhibits low ductility which leads to the formation of second phase and increase in hardness and decrease of tensile strength.