Study On Oxidation Weight Gain And Control Of Inconel 718 Superalloy Electrode

Inconel 718 high temperature alloy is one of the most widely used high temperature alloys at present.Its advantages mainly relies on its matrix γ,γ"phase,the main strengthening phase and auxiliary strengthening phase γ ′ phase,the formation of auxiliary reinforcement phase γ ′ phase mainly rely on Al and Ti elements,so need to strictly control in the process of electroslag remelting of Al and Ti element loss problem.The high temperature oxidation mechanism of Inconel 718 alloy as a consumable electrode in the electroslag remelting process is investigated,which provides a theoretical basis for determining a reasonable deoxygenation system in the metallurgical process,so as to accurately control the oxidizable elements such as Al and Ti of the high temperature alloy.Thistopic determines the oxidation temperature by studying the relationship between electrode and temperature in electroslag remelting process and the thermodynamics of metal oxidation and thermodynamics.Using high temperature furnace energy-saving mosi2 and box-type furnace respectively for Inconel 718 high temperature alloy in air atmosphere oxidation of the 8h under 1150 ℃,1000 ℃,1050 ℃,1100 ℃ and 1150 ℃ under 2h oxidation and variable temperature oxidation.The relationship between oxidative gain and oxidation time was plotted by calculating the oxidative gain.The oxidation products,morphology and composition of Inconel 718 alloy were analyzed by X-ray diffraction instrument,scanning electron microscope and energy spectrum analyzerThe experimental results show that: Inconel 718 under the high temperature alloy in air atmosphere,1000 ℃,1050 ℃,1100 ℃ and 1150 ℃ in a short period of time under the high temperature oxidation in the process of oxidation of the relationship between weight and oxidation time in line with parabola relationship.The oxidation film of Inconel 718 superalloy after high temperature oxidation is divided into outer oxidation layer,intermediate oxidation layer and inner oxidation layer,in which the outer oxidation layer is rich in Fe,Ni and a small amount of Cr elements,the intermediate oxidation layer is rich in Cr and Ti,and the inner oxidation layer is rich in Ti,Al and Nb elements.The strip and bend structure between the alloy matrix and the oxide layer is rich in AlInconel 718 high temperature alloy during high temperature oxidation of Cr and Ni alloy elements such as quickly to form in the oxidation of Ni and Cr spinel oxides,with the increase of oxidation time,oxidation Ti elements formed TiO2,Ti element to spread beyond the formation pore between oxide layer at the same time,accelerate the oxygen to the substrate internal diffusion,thus accelerating the oxidation of other alloying elements.In order to avoid oxidation of Inconel 718 alloy as a consumable electrode in the process of electroslag remelting,inert gas protection or coating of the consumable electrode can be adopted.