| 摘要 |
PROBLEM TO BE SOLVED: To provide a defect prevention method for reducing surface defects which occur by insufficient flame scarfing and rolling after that by forming the stable shape of a rolled stock in a blooming step. SOLUTION: The blooming provided with a hot scarfing step is applied to a steel ingot or a continuously cast steel base stock, wherein the ratio R/W of the radius R of curvature of bulged parts B which are respectively formed on both side faces of the rolled stock 3 on the inlet side of the final pass of rolling before the hot scarfing step to the distance W in the width direction from the side face 3s of the rolled stock on the inlet side of the final pass to the maximum projecting position Bmax of the bulged part is set to be≥0.5. When forming the side face of the rolled stock 3 as mentioned above, because the fall of the rolled stock 3 due to biting does not arise and the hot scarfing can be performed while a stable cross-sectional shape of the rolled stock 3 on the outlet side of the final pass is kept, the defect prevention method is effective to prevent the occurrence of the surface defects. COPYRIGHT: (C)2008,JPO&INPIT
|
