PURPOSE: To roll bar steel by stable reducing work by employing flat passes for other pass stages except shaping passes among reduction rolling passes for square steel and round steel and limiting the aspect ratios after rolling of continuous passes.
CONSTITUTION: A steel blank material W having a square section is subjected to rolling of continuous passes with couples of flat roll pairs 1, 1', 2, 2',Wn, n' whereby the material W is reduced to bar steel of a prescribed sectional shape. In the case of performing the rolling of continuous passes with said flat roll pairs, aspect ratios are adjusted to such ratios at which the long axis B which is the max. size of the cross sectional contour of the rolled material out from flat roll pairs γ, γ' in the respective passes is≤1.5 times the short axis H which is approximately at a right angle to said axis. As a result, the stable rolling is made possible without producing twists and overturns in the continuous passes with the flat pairs.
TANAKA TERUAKI
NODA AKIO
TAKEDA SATORU
INOUE MASATAKA
