HOT ROLLING METHOD FOR ROUND SECTION CONTINUOUSLY CAST INGOT SUBJECTED TO INLINE INDENTATION CUTTING

摘要

PURPOSE:To improve the yield of a product by subjecting a steel ingot to indentation working with upper and lower tools an to shearing with divided tools then to the biting for the 1st pass of a rough hot rolling mill in such a manner that the sharing direction intersects orthogonally with a roll surface. CONSTITUTION:The round section continuously cast ingot is subjected to the indentation working by the upper and lower tools b1, b2 and c1, c2 having a bisected and joined V sectional shape, then to shearing by a pair of the divided tools b1, c1 of the upper and lower tools in succession thereof in the inline cutting of said ingot. The indentation shearing direction in this stage is made parallel with each other at both end faces of the cut ingot; in addition, the ingot is bitten with the tools in such a manner that the indentation shearing direction of the continuously cast ingot is inclined about 45 deg. with the perpendicular direction, i.e., the shearing direction intersects orthogonally with the roll surface in the 1st pass of a square shaped caliber rolling train for hot rolling. The region where the surface flaws of the product are generated is decreased and the yield of the product is improved by the above-mentioned method.