| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide the manufacturing method for steel sheets by which defects of the steel sheet is detected at an early stage and a countermeasure for removing these defective parts is easily worked out. SOLUTION: By providing an ultrasonic test equipment 20 on the inlet side of a pickling tank 8 in a pickling stage after hot rolling, flaw detection is continuously executed about the defects of the hot rolled steel sheet 15 during conveying, stamp (marking) is executed on the surface of the steel sheet in defective parts with marking devices 50 (50a, 50b). In the hot rolled steel sheet 15 after pickling, the stamp is read with a reader 13c and the defective parts on the hot rolled steel sheet 15 are removed.</p> |
