| 摘要 |
PURPOSE:To make the cooling speed uniform on a cooling floor in the pipe longitudinal direction and to prevent a bend, by reducing the heating temperature of the pipe end part where the cooling speed is delayed due to the thickness increase more than other parts. CONSTITUTION:A reheating furnace 1 can re-heat a pipe 2 in about 20m length and the heating zone is partitioned in 1-7 zones. The bend can be prevented by heating the temperature of 1, 7 zone equivalent to the pipe end of the pipe 2 by decreasing about 50 deg.C than the other zone. A reducing mill 3 is provided in succession to the reheating furnace 1 and a rolling material is cooled on a cooling floor 4. |
