| 摘要 |
PURPOSE: A hot rolling method is provided to obtain a steel material with high strength and superior low-temperature toughness by reducing temperature differences between the surface, inside, core and edges of a material. CONSTITUTION: A hot rolling method comprises the steps of: heating a material to the solid solution forming temperature, maintaining the material at temperatures above the solid solution forming temperature, and making the material crack at temperatures below the solid solution forming temperature. The heating step includes a first heating step and a second heating step in which the material is heated at a lower heating speed than the first heating step. The temperature of the material extracted from a heating furnace after the cracking step is 50-100°C lower than the solid solution forming temperature. [Reference numerals] (AA) Temperature; (BB) Time |
