The Effect of Annealing Process on the Microstructure and Properties of Inconel 718 Alloy

Inconel 718 of special metallurgy is often smelted by vacuum induction (VIM)+vacuum consumable remelting (VaR). The continuity and compactness of Inconel 718 Alloy Ingot poured in vacuum induction furnace are the key factors affecting the stability of subsequent remelting. In order to study the effect of annealing process on the internal stress and cracking tendency of Inconel 718 Alloy Ingot, the effects of different annealing processes on the residual stress and hardness of Inconel 718 Alloy were studied, and the residual stress of Inconel 718 Alloy was detected by X-ray diffraction method to confirm the change of internal stress. At the same time, combined with the heat treatment experiment, the influence law of precipitation relative residual stress and hardness was explored. The results show that the annealing heat treatment process at 850 ℃× 5h is an effective method to reduce the residual stress of Inconel 718 Alloy and ensure the material properties. The research indicates that the precipitation of γ 'phase is the key factor leading to the internal stress during the cooling process of ingot.