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Indexed by:Journal Papers

Date of Publication:2019-11-01

Journal:VACUUM

Included Journals:SCIE

Volume:169

ISSN No.:0042-207X

Key Words:Inconel 718 alloy; Electron beam smelting; Evaporation behavior; Alloy elements

Abstract:The Inconel 718 alloy was prepared by electron beam smelting, and the evaporation behavior of alloy elements was studied. The results show that it is feasible to calculate the activity and activity coefficients of Fe, Ni and Cr elements employing the Miedema model. When calculating the activity coefficients of Nb, Mo and Ti, the melt can be approximated as a dilute solution of these elements. While for Al, an activity coefficient compensation factor has to be introduced. As the smelting temperature and time increase, the mass fractions of Ni, Ti; Nb, Mo, and Fe increase, while the content of Cr decreases. As the mass of master alloy increases, the mass fractions of Ni, Nb, Mo, Ti, and Fe decrease first and then remain stable, while Al and Cr show opposite trends. In order to control the alloy composition, the mass of the master alloy should be greater than 1290.7 g. When the smelting power is 15 kW, the maximum smelting time is determined by the Cr, whose value is 673 s. After optimization of the smelting parameters, the alloy composition can be well controlled, and the mass fractions of Cr and Al are only reduced by 0.42% and 0.01%, respectively.