Fabrication of a New Ceramic Coating by Electrophoretic Method for Graphite Electrodes at High Temperature

Abstract

A large part of the cost of steel production in the world is related to the consumption of graphite electrodes. Electrode is the only material that maintains its electrical conductivity at high temperatures, and hence it is used as a conductor of electric current in EAF furnaces. Considering the high costs of graphite electrodes, any action that leads to reducing the consumption of graphite electrode can lead to increasing the productivity of steelmaking operations. In this study and as its novelty, the electrophoretic method was used to generate a ceramic coating for the protection of graphite electrodes. Electrophoretic deposition (EPD) is a two-step process in which charged particles suspended in a suspension move towards the oppositely charged electrode under the influence of an electric field which combine as a dense film on the surface. In the EPD technique, the particle size limit is not very important if a stable suspension is formed and micro and nano-sized particles can be used in this method. The numerical simulation of the thermal contour on the graphite electrode was done in ABAQUS software. Moreover, the surface morphology of graphite samples has been investigated via scanning electron microscopy (SEM). The created coating was a combination of Al2O3 and SiO2, which was placed on the surface of test samples by EPD treatment. The obtained results have the properties of resistance to thermal shock and show the increase in the life of coated graphite samples at different temperatures and times.