PURPOSE: To improve the yield of a hot slender material in its cutting-off, by adopting a method of taking the length of the defective front part of the material into consideration to determine the cut-off length of the first piece.
CONSTITUTION: After a slender material W sent out of a finish-rolling machine 1 is cut off to a prescribed length by a cutting-off machine 11, the material is cooled. The material is then sent out from the cooling bed so that a prescribed number of such materials are prepared and then cut off to a product length by a cooling and cutting-off machine. In that case, a data processor 6 performs combined calculation on the basis of the predicted overall length, the temperature of the hot slender material W, the final product length, a tolerance and the length C of a flaw-including part. The length of the first cut-off piece including the front part of the slender material W is made larger than that of the second and succeeding cut-off pieces determined in relation with the overall length of the slender material, by a length prescribed depending on the specifications of the material. According to this cutting-off method, the yield of the material is improved and the production efficiency is heightened.
YAMAUCHI YUTAKA
KOBAYASHI HAJIME
UENO YASUNAGA
