ROLLING OF BAR STEEL OR WIRE ROD WITH SMALL FINISH CIRCULAR ERROR

摘要

PROBLEM TO BE SOLVED: To roll steel bar or wire rod having small finishing circular errors by providing at least two successive rolling stands having large rigidity as precise rolling stands in a rolling mill. SOLUTION: A first precise rolling stand 5 is formed as a vertical stand and its rolls are provided with an egg shaped pass. A second precise stand 6 is formed as a horizontal stand and its rolls are provided with a circular shaped pass. The first rolling stand 5 is provided with a precise measuring device 9 and the width of egg shaped steel bars or wire rods 2 coming out of the stand 5 are always detected. The variation of measured width of egg shape is utilized in order to change at least the number of revolution of one side of the precise rolling stand so that the correct width of egg shape is always kept for adjusting tensile force between both stands 5 and 6. By this way, the rolling mill having small finishing circular errors is obtained.