END PORTIONS OF LARGE-DIAMETER TUBES CALIBRATION METHOD

摘要

FIELD: tube production, namely processes for calibrating tubes rolled in tube-rolling aggregates possibly with pilger mills. ^ SUBSTANCE: end portions of large-diameter tubes are calibrated by means of one pair of preliminarily calibrated rolls at reverse rotation by 90 - 110°. Length of calibrated zone is set by means of movable stops arranged in front and after calibrating rolls. Rear and front ends of tubes are reduced by diameter by means of different portions of calibrating rolls. After first reduction of front and rear ends of tube the last is rotated around its axis by angle 10 - 90° and it is again reduced. After calibration of front end of tube the last is moved according to manufacturing process through open non-calibrating portion of gage and rear end of tube is subjected to calibration. ^ EFFECT: possibility of calibrating front and rear ends of tubes directly in manufacturing flow at desired allowance by diameter. ^ 5 cl