| 摘要 |
PROBLEM TO BE SOLVED: To provide a method capable of effectively preventing occurrence of stripping errors and seizure at an initial time of mandrel rolling.SOLUTION: A method of manufacturing a seamless steel pipe includes a repeating step of inserting a mandrel bar 2 to an original pipe 1 to perform mandrel rolling, pulling out the mandrel lever from the steel pipe subjected to the rolling, immersing the mandrel bar in a bar cooling water tank 4 for cooling, and then reusing the mandrel bar. Before the mandrel bar is inserted to the element pipe at an initial time of the repeating step, the mandrel bar is immersed in water in the bar cooling water tank of which water temperature is 50-100°C. |
