METHOD FOR CONTROLLING POURING FLOW RATE OF MOLTEN STEEL IN CONTINUOUS CASTING

摘要

PROBLEM TO BE SOLVED: To obtain the excellent controllability of pouring flow rate of molten steel without increasing the variation of a molten steel surface level in a mold even at the time of progressing the erosion in a nozzle or a stopper in multi- sequential continuous casting. ;SOLUTION: At the time of controlling the pouring flow rate of the molten steel into the mold by a stopper system in the continuous casting, an mutual relation between a stopper receiving part 1 material in the upper part of the nozzle and a nozzle abutting part material in the lower part of the stopper 2, is regulated so that the eroding ratio (eroded thickness of the stopper receiving part in the upper part of the nozzle/eroded thickness of the nozzle abutting part in the lower part of the stopper) becomes ≤0.5 and the shape of the stopper receiving part 1 in the upper part of the nozzle is formed into a conical shape. Further, the material of the receiving part 1 in the nozzle has a composition consisting of ≥70 wt.% zirconia content and ≤30 wt.% carbon content and on the other hand, the material of the nozzle abutting part in the lower part of the stopper 2 has a composition consisting of one or more kinds among ≥30 wt.% silica, ≥50 wt.% carbon, ≥30 wt.% alumina and ≥ 40 wt.% spinel.;COPYRIGHT: (C)1998,JPO