| 摘要 |
PURPOSE:To prevent generation of a crack at the time of bead treatment, by providing a bead part heating device and a lubricating oil heating device on a TIG welding pipe manufacturing device, and also heating the lubricating oil to a transition temperature or above of the bead part. CONSTITUTION:A bead part heating device 10 of a steel pipe 2 is placed on this side of an outside face rolling reduction roll 8 in the rear of an outside face polishing machine 5 of a TIG welding pipe manufacturing device. In this state, the bead part of the steel pipe 2 is heated to its transition temperature or above, and the bead part is pressed and smoothed by an inside face rolling reduction roll 6 and an outside face rolling reduction roll 8. In this case, lubricating oil supplied to the outside face rolling reduction roll 8 is collected to a collecting tank 14, is fed to a heating tank 16 by a pump 15, and the lubricating oil is also heated to a transition temperature or above of the bead part. Subsequently, it is stored temporarily in a storage tank 17 and is supplied to the outside face rolling reduction roll 8 and the inside face rolling reduction roll 6 by a flow rate adjusting device 18. Also, in case when thickness of a pipe is thin, and a temperature in case of bead treatment can be raised to the transition temperature or above by friction heat of the outside face polishing machine 5, it is unnecessary to operate the bead part heating device 10. |
