Precipitation of (Zr, Hf)C in FeCrAlYHfZr alloys during electroslag remelting process

¹ School of Metallurgical and Ecological Engineering at University of Science and Technology Beijing (USTB), Beijing 100083, China
e-mail: zhanglifeng@ustb.edu.cn
² Ironmaking Plant, Wuhan Iron and Steel Company Limited, Wuhan 430083, P.R. China

Received: 14 July 2016
Accepted: 1 August 2016

Abstract

Three-dimensional morphology of (Zr, Hf)C in FeCrAlYHfZr alloys during electroslag remelting (ESR) was revealed by the method of non-aqueous solution electrolysis. Two types of (Zr, Hf)C carbides in FeCrAlYHfZr alloys were detected: isolated cubic carbides of (Zr, Hf)C were precipitated in intragranular and dendritic ones were precipitated in the grain boundary. In alloys with sufficient [C], there was a linear relationship between the (mole pct Zr)/(mole pct Hf) in carbides and [mole pct Zr]/[mole pct Hf] in alloys with the slope close to unity, while HfC was easier to be formed than ZrC in alloys with insufficient [C]. Extensive calculations were carried out to predict the composition of (Zr, Hf)C in FeCrAlYHfZr alloys with various concentrations of [Zr], [Hf] and [C].