| 摘要 |
PURPOSE:To reduce skin flaws and lug-split defects to a great extent by the procedure in which face-cutting is made for the upper and lower surfaces of slab prior to rough rolling and at the same time the sectional shape in the 4-corners of rectangular section is cut to the predetermined dimensions, and then rough rolling in the longitudinal direction is made while making rolling in the width direction. CONSTITUTION:The corner rounding for the 4-corners of slab is made in general in the conditions of a fellet width w of 5 to 40 mm, a fillet depth t of t >= T/20 (T is the thickness of slab), and a cutting amount of the upper and lower surfaces a of 3 to 15 mm. For vertical roll and edger, the number of uses of edger and the pressure lowering amount are selected properly according to the rolling degree of base metal and the pressure lowering amount of rough rolling. This method raises yield greatly and also reduces the amount of cuttings, thus reducing the remelting loss of cuttings. |
