Method for reducing the length of thickened ends when rolling pipes in a stretch reduction rolling mill

摘要

The invention relates to a method for minimizing thickened ends during the rolling of pipes in a stretch reducing mill. To this end the torque of individually driven mill stands is temporarily modified when the front and back ends of the pipes pass through the stretch reducing mill so that said pipe ends are rolled at roll speed ratios which are greater than the steady-state roll speed ratios. Between the steady-state and the increased speed ratios smaller than steady-state speed ratios are set.