METHOD FOR STRAIGHTENING WARPAGE OF SEAMLESS STEEL TUBE

摘要

PURPOSE:To straighten the warpage of a steel tube with high precision and to improve the yield by arranging three rolls at a specified angle and at a specified interval in the preceding process of a sizer, rolling down the steel tub with rolls in the direction of a tube diameter and giving a tension to straighten the warpage of the steel tube. CONSTITUTION:A set of three parallel rolls 2a, 2b, 2c having a long barrel each are arranged respectively in parallel and at an interval of 120 degrees with the roll axis of the steel tube. The steel tube 1 is clamped by a clamping device 3 rotatably. Plural sets of this straightening device are arranged in front of the sizer, to which the steel tube 1 is supplied from the rolls. Compressive load is given by the parallel rolls 2a-2c rotating in the same direction in linear contact on the outer circumference of the steel tube 1 and rolling-down force is exerted in the direction of the tube diameter to make a required deformation. The steel tube 1 is rotated in an arrow direction under a rolling-down force and drawn, extracted by the external force given to the clamping device 3 in the arrow direction. In this way, the warpage of the steel tube can be straightened with high precision.