Physicochemical processes during the contact of steel with casting nozzles

Abstract

The results of physicochemical processes taking place in casting nozzles depend on the content of the steel of chemically active components and the composition of the refractory. An examination of the phase diagram of the systems forming contact zones in the nozzles enabled us to obtain a nomogram for determining the degree of erosion or tightening up of the nozzles in the intermediate ladles as a function of the composition of the refractory material and the content of aluminum in the steel being cast. In order to explain the stable feed of metal from the intermediate ladels in continuous steel casting plant in the crystallizer we recommend the casting of rimmed steel through magnesite nozzles, killed steel with a content of less than 0.01% aluminum through zircon nozzles, and containing more than 0.01% aluminum through fireclay (35–40% Al2O3).