Dynamic de-oxidation and inline alloying of Al in continuous casting of billets and strips

Abstract

The method of controlled stepwise de-oxidation and alloying of carbon steel melt with Al-wire has been investigated. The melt is pre-deoxidized in the ladle, the main fraction of non-metallic inclusions is removed to the ladle top slag by stirring. Final de-oxidation and alloying takes place just before solidification in the continuous casting mould. In three steps from laboratory via a pilot facility to an industrial caster the efficiency of that method was tested. No disadvantage could be found; the benefits are high amount of [Al]diss., high yield rate, better macro-cleanliness, and improved process quality by avoiding depositions and clogging. By that method, the production of Al-killed carbon steel grades should be possible also with near-netshape casters which use in general small orifices in tundish and SEN.