CONTINUOUS HOT ROLLING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a continuous hot rolling method by which the breaking of a sheet during rolling and the damage of the roll of a rolling mill are prevented by combining the joining manner of 'taper lap' and partial joining method. SOLUTION: In the continuous hot rolling method of executing hot rolling by making joint surfaces 3 of a preceding slab 1 and the succeeding slab 2 parallel to each other in the width direction of the slab and at a certain angle α deg.to a rolled surface and preliminarily welding a part of the respective surfaces, this continuous hot rolling method satisfies following conditions. (a) The above αis <=50. (b) The preliminary joining is executed over the entire length of joint lines in both side end parts of the slab which are formed with the joint surfaces of both slabs by laser beam welding and the respective depths of penetration are taken as >=1% of the width of the slab.