Rolling manner and its rolling mill string null of rectilinear die

摘要

PURPOSE:To allow selective formation of web thicknesses, joint part thicknesses and effective widths to arbitrary sizes by providing a pair of upper and lower helical rolls adjustable in width in the direction orthogonal with a rolling direction between an intermediate rolling stage and a finish rolling stage. CONSTITUTION:An ingot 10 having a rectangular or dogbone shape in section as a stock is rolled to a roughly molded material by a breakdown mill BD in the roughing stage as the method for rolling a straight type steel sheet pile 5. The molded material is then rolled by intermediate universal mills R1, R2 and edger mills E1, E2 to intermediate rolled stocks 15, 16 having an approximately H section in the intermediate stage. Finally, the flange parts of the intermediate rolled stocks 15, 16 are curved or shaped by vertical horizontal rolls to form the joint parts 18, 19 in the finish rolling stage. A pair of the upper and lower helical rolls 45, 46 which come into contact with the inner side of the flanges of the intermediate rolled stocks 15, 16 and the axial centers of which have the prescribed axial angle alpha with the plane orthogonal with the horizontal plane of the rolling direction are provided adjustable in width in the rolling direction between the above-mentioned intermediate stage and the finish rolling stage.