MANUFACTURE OF SHAPE STEEL

PURPOSE:To directly striaghten without going through a cooling bed after completion of a finishing rolling by deciding a cooling speed by the plate thickness on each part in the cross section intersecting at right angles with the length direction, the component of the shape steel for the shape steel just after completion of hot finish rolling and rolling conditions. CONSTITUTION:The shape deformation of a shape steel is taken into consideration in case of a cooling and the cooling conditions are set as well by combining the material control. For instance, in the case of obtaining a H shape steel 7 by a hot finish rolling from the rolling steel for general structure a cooling is started after going through the temp. fall by the cool release at about 50 deg. C after rolling. The temp. distribution after rolling of the flange 7a and web 7b of the H shape steel 7 respectively varies and the cooling speed is decided from the conditions of the steel material component, shape steel plate thickness, rolling finish temp., cooling start temp., etc., without performing a forced cooling equally. And after cooling until the mean temp. of the whole cross section becomes 150 deg.C by the cooling speed on each part the straightening is performed directly without going through the cooling bed.