Modernization of continuous casting machines with the purpose of increasing of finished product quality

Abstract

To prevent formation or suppress development of crystallization,shrink and liquating defects different methods of physical impact on setting melt are used. For technology selection in every case economy, efficiencyand ecological norms should be considered first of all.Methods of physical impact on crystallizable billet considered: electro-hydro impulse impact, gas-impulse stirring, modifier input, inoculator input, consumable coolers input, ultrasonic impact, “soft” reduction, electromagnetic stirring (EMS).Due to authors’ opinion, EMS of liquid portion of a CC billet is the most effective method ofactive impact on crystallization process of a CC billet directly during casting resulted in a guarantee possibility to control the process of structure formation. At present in world practice the EMS of liquid metal at CC machines became an integral part of advanced technology of high quality billets obtaining. The requirements increase to products qualityand development of effective methods and means of melts electromagnetic processing resulted in a requirement of obligatory EMS usage when producing products of high quality steels.It was shown, that for a number of CC bullet macrostructure defects, arising from crystallization process, shrinkage and liquating phenomena, which can not be eliminated completely even at optimal CC machinesdesign features and rational technology parameters of CC process, additional methods of physical impact on the liquid metal setting needed. The method to be used depends on the CC technology and existing CC machines equipment.