Reduction of Tundish Stopper Rod Corrosion Caused by Covering Powder

Using tundish covering powders based on the Ca–aluminate system can be advantageous since they present better performance regarding absorption of inclusions and prevention of steel reoxidation by the atmosphere. However, producing ultralow‐carbon steel can lead to severe corrosion of the tundish stopper rod at the slag line when using this material. The corrosion rate can be so high that the stopper rod fractures, causing an interruption in the production sequence. Considering that corrosion is primarily a chemical process, and the potential for corrosion can be estimated through chemical equilibria calculations, simulations using computational thermodynamics are performed to design tundish‐covering powders to reduce the stopper rod corrosion rate at the slag line. Then, a new Ca–aluminate material is produced and tested at a steel mill. The stopper rod wear rate decreased more than six times on average with the optimized tundish covering powder. Steel cleanliness is not affected by the change in the covering powder.