Method of improving the tolerances of outside diameter and of wall thickness during size-rolling and stretch-reducing of roughly pierced tube blanks

摘要

In order to provide a method of avoiding differences in the diameter or wall thickness of the finished tubes resulting from different temperatures of the roughly pierced tube blank, it is proposed that the temperature of the roughly pierced blank be measured over its length before introduction into the rolling mill and that the rolling speed be adjusted by regulating the number of revolutions as a function of temperature drop in such a way that, during rolling, an opposite temperature increase or decrease of the roughly pierced tube blank in accordance with the measured temperature drop takes place.