This paper presents the experimental results on a model regarding the stirring energy and mixing time of liquid steel refined with inert gas. The researches were focused on determining the stirring energy and mixing time for different systems and working parameters. For all the analysed cases an inversely proportional variation of mixing time versus stirring energy and gas flow rate was observed. The variation of the mixing time function of the injection

Semifinished continuously cast steel products represent the optimum solution for raw materials for hot-rolling sectors in that they present low costs and satisfactory quality. It should be observed though that, sometimes, longitudinal fissures appear on the surface of these semifinished products. The paper presents the results of material investigations undertaken at A.M. Hunedoara, using discs taken from continuously cast blooms on faulty areas.

An efficient solution to the manufacture of tubular products lies in the use of continously cast round billets, as they present lower costs and satisfactory quality. The study analyzes the factors that determine high performance results of this solution: quality of liquid steel, technological level of the casting system, parameter-optimized automatic control and regultion of the whole process and data monitoring and processing. The research analyzes