METHOD FOR CONTROLLING CASTING OF INGOT

PURPOSE:To form an ingot having excellent quality by elucidating the association between the distribution condition of defects and steel making conditions, comparing the distribution condition of the defects discriminated by an ultrasonic flaw detection and the standard defect pattern and changing the steel making conditions according to the result of the comparison. CONSTITUTION:Part of the region of the continuously cast ingot or the rolling steel product obtd. from such ingot is subjected to the ultrasonic flaw detection over the entire surface in the transverse direction thereof. The distribution condition of the detects by the result of the flaw detection and the standard defect pattern are compared and the defect condition of the ingot or slab is judged. One or >=2 of the steel conditions such as the casting speed, depth of a immersion nozzle, additives for steel making and others are corrected to eliminate the defects in accordance with the result of the judgement.