NON-UNIFORM WATER FLUX DENSITY APPROACH APPLIED ON A MATHEMATICAL MODEL OF HEAT TRANSFER AND SOLIDIFICATION FOR A CONTINUOUS CASTING OF ROUND BILLETS.

In the present work, the water flux densities of nozzles with flat jet and full cone jet were experimentally measured using an apparatus in industrial scale that reproduces the secondary cooling of the continuous casting of round billets of Vallourec Tubos do Brasil. A mathematical model for heat transfer and solidification for the continuous casting of round billets was developed applying the experimental water flux density profile, establishing a non-uniform water distribution approach. The mathematical model was validated by experimental measurements of the billet superficial temperature, performed at the industrial plant. The results of the mathematical model using both uniform and non-uniform water flux density approaches were compared. The non-uniform water distribution approach enabled to identify important variations of the heat transfer coefficients and the billet temperatures, especially in the first cooling zone, and to assess more accurately the local effects of the water distribution on the thermal behavior of the strand. The non-uniform water flux density approach applied to the mathematical model was a useful and more accurate tool to improve the comprehension of the thermal behavior of the steel along the secondary cooling. [ABSTRACT FROM AUTHOR]