METHOD FOR PREDICTING QUALITY OF SLAB USING DEFECT INDEX OF IMPURITIES COMEING OFF SUBMERGED ENTRY NOZZLE

摘要

PURPOSE: A slab quality prediction method using a defect index of inclusion drop-out is provided to implement precise prediction of slab quality by predicting the inclusion drop-out degree of an immerged nozzle through frequency analysis of molten metal level and using the initial solidification nonuniformity according to the temperature variation of a side of the mold. CONSTITUTION: A slab quality prediction method using a defect index of inclusion drop-out comprises the steps of: measuring a molten metal level signal and a one-side copper plate temperature signal from a mold(30), dividing the molten metal level signal and the one-side copper plate temperature signal according to slab, obtaining the area of a region of 0.1Hz or less, the number of time of exceeding a reference level, and a defect probability index from the signals, and calculating a defect index of inclusion drop-out.