JPS57195508A - Rolling method for thick plate - Google Patents

Abstract

PURPOSE:To prevent a rolling material from a fluting, generating at the tip of the material when biting it at the final pass in hot rolling, by rolling the material to make its top side thicker than the finish thickness at the final finishing pass, and performing a dummy pass by bringing said side to the top side reversely. CONSTITUTION:In cases of pass schedules that the difference between the thickness t2 of a rolling material A obtained after completing a rolling pass just before the final finishing pass, and the finish thickness (t) is >=1-2mm., or <1mm. the next rollings are performed respectively as follows. First in the former case, a roll gap t1 at the finishing pass is set to be >=1-2mm.+(t), and immediately after rolling the top part of material A by the length (l) into the thickness (t1), the roll gap is set to the thickness (t) to roll a remained part into the thickness (t) to obtain a material B, and then said thicker part 10 is rolled into thickness (t) by reversing the rolling direction and setting the gap to the thickness (t) in a dammy pass. Next, in the latter case, the roll gap is set to the thickness (t) to roll the remained part into the thickness (t) immediately after passing the material A as it is without changing the gap, then the material is reversed in a dummy pass to roll the remained part into the final thickness (t) by making said part the rolling top reversely.