Performance Features of Submerged Entry Nozzle in High-Speed Casting on Thin-Slab CC Machine

Abstract

The development of the beyond-design productivity of a thin-slab CC machine has revealed abnormalities in the performance of a submerged entry nozzle. They are characterized by the mechanical failure of the refractory wall around the pony ladle attachment fitting. As established by the tests, the failure is caused by induced mechanical vibrations affecting the horizontal axis. Their occurrence has to do with the formation of hydrodynamic flux cycles in the molten metal of the crucible. These cycles transmit a sign-variable pulse to the submerged refractory body. It is established that the nozzle vibration frequency is similar to the crucible swinging frequency. An efficient solution for stabilizing the mechanical durability of the refractory was to enhance the configuration of the pouring nozzle in the pony ladle attachment fitting. This modification has improved the refractory item resistance to the hydrodynamic effects of the molten metal and allows continuing to increase the productivity of continuous thin-slab casting.