Physical and mathematical modelling of argon shroud for protection of steel stream during casting

Abstract

Physical modelling of argon shroud was carried out using a two-dimensional 1 : 1 scaled model in order to gain a basic understanding of air entrainment during casting. The flow pattern of protective gas was determined with particle image velocimetry technique. Computational fluid dynamics calculations were also conducted. The results of the particle image velocimetry measurements and computational fluid dynamics modelling showed mutual agreement. The main findings of the present study are the following. First, the use of vertical gas inlet outside the collar on the top of the vertical runner should be avoided. Second, the distance between the ladle and the collar should be minimised to reduce the oxygen entrainment by convection and diffusion. Third, a modest flowrate of argon gas should be used. Further increase in the gas flow does not seem to improve the protection.

Keywords:

• ARGON SHROUD
• INGOT CASTING
• REOXIDATION
• COLD MODEL
• PIV
• CFD