Yield of Y, La, Ce in high temperature alloy during electroslag remelting process

¹ School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, P.R. China
e-mail: zhanglifeng@ustb.edu.cn
² Center for Iron and Steelmaking Research, Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA
³ Ironmaking Plant, Wuhan Iron and Steel Company Limited, Wuhan 430083, P.R. China
⁴ 4. CISDI R&D Co., Ltd, Chongqing, Chongqing 401122, P.R. China

Received: 1 December 2015
Accepted: 10 March 2016

Abstract

In the current study, samples of ingots and slags after electroslag remelting (ESR) were analyzed to investigate the reoxidation of the rare earth (Re) metals Y, La and Ce from high temperature alloys during remelting. The yield of Y, La and Ce in high temperature alloys during ESR is enhanced by increasing the concentrations of their oxides in the slag, and by adding CaO to the slag. Alumina in the slag should be avoided during ESR, since Y, La and Ce are easily oxidized by Al₂O₃, and because Al₂O₃ lowers the activity of the rare-earth element oxides. The effect of Re₂O₃, CaO and Al₂O₃ content in the slag on the activity of Re₂O₃ was estimated using the Temkin model.