IMMERSION NOZZLE FOR CONTINUOUS CASTING

摘要

PROBLEM TO BE SOLVED: To restrain the sticking of non-metallic inclusion to the bell, part of an immersion nozzle by arranging horizontal and vertical through-holes for gas blowing regulated with diameter size and the number thereof respectively on the upper surface and the side surface of the bell part of the immersion nozzle. SOLUTION: An annular hollow chamber 5 for blowing gas into the bell part 6 of the immersion nozzle 1 for continuous casting which pours molten steel into a mold from a tundish, is provided. The >=10 pieces of vertical through-holes 3 are arranged on the upper surface of the bell part 6 from the hollow chamber 5 and the 1-15pieces of horizontal through-holes 4 are arranged on the side surface thereof and the diameter of each of through-holes 3, 4 is made 200-500μm. In this constitution, inert gas is supplied from a supplying hole 8 into the hollow chamber 5 under the constant pressure to execute gas bulling. By this method, non-metallic inclusion is floated up and the sticking of the inclusion to the part between the bell part 6 and a stopper 2 is restrained and the steel quality is remarkably improved.