Success or failure decision method null of suffering inspection material such as

摘要

PURPOSE:To obviate overestimating and overlooking of sub-source flaws by combining the results of flaw detections by various flaw detection methods including surface flaw detection, angle beam flaw detecting and normal beam internal flaw detection to make decision on acceptance or rejection of a material to be inspected. CONSTITUTION:The material to be inspected such as billet is subjected to the flaw detection by the surface flaw detection using a surface flaw detector such as magnetic particle flaw detector, the ultrasonic angle beam flaw detection using an ultrasonic flaw detector and the ultrasonic normal beam internal flaw detection, respectively. As to the flaws shallower in the evaluated flaw depth than the flaw removing limiting value among all the flaws detected by the surface flaw detection and the flaws detected by the angle beam flaw detection, the flaws in the respective evaluated flaw positions are removed down to the flaw removing limiting value. The flaws which are detected by the normal beam internal flaw detection and the flaws which are deeper in the evaluated flaw depth among the flaws detected by the angle beam flaw detection are processed as the internal flaws (including the sub-surface flaws).