Nitrogen alloying of liquid steel by gas injection in the ladle and/or converter

Trials of nitrogen alloying of liquid steel by bottom nitrogen-gas injection during the post-blow stir in the converter, and in the steel ladle at atmospheric pressure and under vacuum were performed in the steel plant of the AG der Dillinger Huttenwerke.A unified model, valid for both converter and steel ladle was developed to describe nitrogen pickup in liquid steel by gas injection. By a tailored nitrogen stirring in the converter and/or ladle, it is possible to reach an aimed nitrogen range with good accuracy.