| 摘要 |
PURPOSE:To improve the yield of product and to save the consumption of energy by obtaining the difference DELTAT between the boundary temperature, between a deformation region and a nondeformation region, and the lowest temperature in the cross section of a hot billet by using a specific equation in accordance with the whole rolling reduction DELTAE in the width direction of hot billet. CONSTITUTION:In accordance with the whole rolling reduction DELTAE in the width direc tion of a hot billet, the temperature difference DELTAT between the temperature TA of a boundary surface part PA, between the deformation and nondeformation regions of billet, and the temperature TB of the lowest temperature part CP in the cross section of billet, is calculated by using an equantion (1). The hot billet is reheated to be rolled in its width direction, by regulating the difference between the temperatures TA, TB to be equal to or lower than the calculated value. Because the difference between the temperatures TA and TB is regulated by the equation (1), the difference of metal flow in the rolling direction between the surface layer part and inner part of the billet is decreased, and the shear cracking in the surface layer part is reduced. Accord ingly, the generation of surface flaw is reduced to improve the product yield and the useless heating is reduced to save the energy consumption. |
