METHOD FOR MANUFACTURING HOT ROLLED LONG COIL

• Main Authors: KUBOYAMA EIICHI, NAKAMOTO TAKEHIRO, TAZAKI FUMITADA, YOSHIYAMA TOMOAKI, KARASHIMA HIROSUKE, TAKAHASHI KOUYA
• Format: Patent
• Language: English
• Published: 25.05.2006
• Subjects: MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; PERFORMING OPERATIONS; PUNCHING METAL; ROLLING OF METAL; TRANSPORTING

PROBLEM TO BE SOLVED: To provide a method for manufacturing a long coil having a long coil length, which method can avoid the processing troubles caused by the bad shape in a finish rolling process due to the increase of the coil length (the increase of the weight per a coil) and the long stoppage of the rolling line caused by treating the residue of the coil, and further can prevent the generation of the scale defects due to the temperature rise at the surface of steel strips, by a small electric power of a bar heater and without deteriorating the homogeneity of material quality. SOLUTION: A heating pattern of the bar heater for carrying out the heating control for the whole width of a rough bar is varied according to the temperature drop of the rough bar located on the inlet side of the finish rolling mill with the progress of the finish rolling process such that the temperature difference between the portion from the quarter portion of the width to the middle portion of the width and the portion from the edge portion to the quarter portion is within the temperature difference which does not cause the drawing defects. In addition, the heating is carried out while continuing the increase of the rolling speed after the leading edge of the coil has engaged with a coiler until the tail edge of the coil has passed the utmost upstream side stand of the finish rolling mill. COPYRIGHT: (C)2006,JPO&NCIPI