METHOD FOR HOT CUTTING OF CROP AND DEVICE THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a cutting method by which the shape of a cut surface in a joined part in continuous hot rolling, controlling the variation in the cutting angle of cutting tool smaller than in the conventional method and making the butting at the time of joining surer and a device therefor. SOLUTION: This crop cutting device consists of an inlet-side plate pressing device 16 and an outlet-side plate pressing device 17 in which a bar is moved while restraining it by a constant load of 3-15% of cutting load with an upper cutting tool 2, an lower cutting tool 3 and the plate pressing surface corresponding to the ascent and descent of the cutting tools on the line-symmetric position of respective upper and lower cutting tools to the bar and, when the cutting tool are opened to the thickness of the bar after cutting, the bar is released. The crop cutting device has a structure with which a cutting start angleβsatisfies -1.0<=β<=1.0 in the range of bar thickness of 25-50mm in order to reduce the variation in the cutting angle. By taking a plate pressing angleαas -1.0<=β<=4.0 deg., the variation in the cutting angle of the cutting tool is reduced and inconvenience due to the variation in the cutting angle of the cutting tool at the time of joining is prevented.