JPS5447851A - Rolling method for slab by universal blooming kmill - Google Patents

Abstract

PURPOSE:To roll the slab at good rolling yield and superior dimentional accuracy and productivity, by arranging the caliber in the horizontal roll of the universal blooming mill, and by concentrically carrying out the reduction in the direction of breadth of the material depending on this caliber of the horizontal roll during the stage of intermediate rolling. CONSTITUTION:The initial reduction of the breadth of the steel ingot is carried out by the smooth first rolling face 3a, 3b, of the horizontal roll 1a, 1b, and then, the descaling is carried out. After the material is 90 degrees turned, the reduction in the direction of thickness is carried out by the first rolling face 3a, 3b, of the horizontal roll 1a, 1b, and the vertical roll 2a, 2b. Next, at the stage where the thickness of material becomes 50-30% of the initial thickness, the material is 90 degrees turned, and then, the reduction in the direction of thickness is concentrically carried out by the second rolling face 4a, 4b, and the third rolling face 5a, 5b, which are all provided with calibers, of the horizontal roll 1a, 1b. In the last stage, when the material is rolled into aimed size of breadth approximately, the material is again 90 degrees turned, and the finish rolling is carried out by the first rolling face 3a, 3b, of the horizontal roll 1a, 1b, and the vertical roll 2a, 2b; hereby, the slab of the specified size is obtained.