METHOD AND DEVICE FOR CONTROLLING ROLLING IN ONE-STAND-MULTIPASS ROLLING MILL

摘要

PURPOSE:To restrain offgages only near to welding zone of a rolled stock by temporarily opening a gap between work rolls so as to reduce variations in a load of the work rolls caused by welding zones when the welding zones of the rolled stock pass through the gap. CONSTITUTION:A one-stand-multipass rolling mill rolls a rolled stock S having welded joint parts P continuously through respective gaps G1, G2, and G3 between work rolls R1, R2, R3, and R4. A computing element 4 obtains the timing at which a joint part P passes through gaps G1... based on a distance L between the rolling mill and a joint detector 5, a moving speed V of the stock S by a speed detector 6, and the detected timing of the joint part P by the detector 5. A control system A adjusts the position of corresponding rolls R1... and opens gaps G1... temporarily in accordance with the passing timing of the joint part P obtained by the computing element 4. In this method, offgages are restrained only near to joint parts of the rolled stock, so that a yield is improved.