Study of Steel Slab Shrinkage Features During Steel Continuous Casting

Аннотация

A method is developed for calculating absolute and relative values of steel slab linear shrinkage in a CBCM. Using existing mathematical models for slab solidification and cooling, supplemented by a method developed for calculating shrinkage, the effect of various CBCM process and design parameters in PAO Severstal’ on slab cross section reduction is studied. As a result of studies, a general pattern is found that describes the effect of carbon content and the distance from the metal surface in the mold with a casting rate of 1.0 m/min on the magnitude of steel slab relative linear shrinkage. It is found that alloys with a high carbon content have lower tendency towards shrinkage. The most significant influence of carbon content in an alloy on the amount of shrinkage is observed in the concentration range 0–0.16% due to δ → γ transformation. If the carbon content is higher than 0.16%, shrinkage slows down with an increase in carbon content due to the influence of volumetric change inhibited by a small quantity of liquid circulating between the dendrites, due to which the solidus temperature decreases, and steel only shrinks due to thermal contraction. The pattern obtained can be used in CBCM design with installation of a dynamic soft reduction system.