A study on the electrochemical deoxidation using ZrO₂ based solid electrolyte and a periodic DC voltage

An electrochemical deoxidation using a ZrO₂ based solid electrolyte was investigated to control the interfacial oxygen concentration between the molten steel and ZrO₂. The electrochemical deoxidation cell consisted of an MgO stabilized ZrO₂ and an external power supply. In a previous study with constant external DC voltage, the oxygen concentration at the interface between the solid electrolyte and the molten steel was decreased to 2.2 ppm, which was the limit caused by the cathodic over-potential when a constant external DC voltage was applied. In the present study, a novel process of using a periodic or cyclic voltage for the electrochemical deoxidation cell was developed, to surpass this limitation caused by the over-optential of the electrochemical cell and thus decreasing the oxygen concentration to sub-ppm levels at the interface between the molten Fe and the solid electrolyte.