PINHOLE DEFECT REDUCTION METHOD IN A CONTINUOUS CASTING CAPABLE OF CONTROLLING A COLLISION DEPTH BY PREDICTING THE DEGREE OF A PINHOLE DEFECT BY A MEASURED COLLISION DEPTH

摘要

PURPOSE: A pinhole defect reduction method in a continuous casting is provided to firstly control a collision depth by measuring the used amount of argon gas and the submerged depth of a submerged nozzle when the degree of the defect of a pinhole defect, and then the casting speed when the used amount of argon gas and the submerged depth reach the predetermined limit.;CONSTITUTION: A pinhole defect reduction method in a continuous casting comprises the following steps of: storing(S11) data about various operation factors including a casting width, the use of molten steel, the submerged depth of a submerged nozzle and the use of argon gas, calculating(S12) the collision depth from the break surface on which the molten steel ejected from the submerged nozzle is collided with the inner wall of a mold, determining(S15) which is variably controllable for at least one of the submerge depth of a submerging nozzle or the use of argon gas to reduce the collision depth below a standard depth when the calculated collision depth is above the standard depth based on the comparison of the calculated collision depth with the predetermined standard depth, and decelerating(S19) the speed of casting if neither the submerge depth of a submerging nozzle nor the use of argon gas is variably controllable.;COPYRIGHT KIPO 2013;[Reference numerals] (AA) Start; (BB,EE) No; (CC,FF) Yes; (DD,GG) End; (S11) Storing various operation factors(casting width, casting speed, submerging depth, use amount of argon gas, etc.); (S12) Calculating a collision depth using the operation factors; (S13) Comparing the calculated collision depth with a reference depth; (S14) Is it equal to or greater than the reference depth?; (S15) Determining whether it is possible to control the submerging depth and the use amount of argon gas within a set range to be equal to or less than the reference depth; (S16) Is it possible?; (S17) Changing at least one of the submerging depth and the use amount of argon gas within the set range; (S18) Continuously casting with the set operation factors; (S19) Reducing the casting speed in comparison with the current casting speed