Continuous casting technology of hot cycle operations of tundish for clean steel slabs

In order to minimize the refractory and relining labor cost of tundish and to achieve high productivity, a practice of hot tundish recycling has been introduced at the No. 4 slab caster at Mizushima Works. A remarkable extension of tundish refractory life is obtained with the hot cycle tundish operation. Firstly, the skull and slag is dumped out of the tundish immediately after the end of casting at casting floor, followed by a quick exchange of the tundish nozzle. Then, the tundish is kept hot enough and inert with the N2 jet heater which can prevent the oxidation of adherent metal so as to secure the bottom slab qualities at the next casting. This report describes the successful recycle operation of hot tundish featuring the newly developed N2 jet heater and its effects on the slab qualities.