| 摘要 |
PURPOSE:To prevent the generation of outer surface flaws of a finished pipe by gradually reducing the outer diameter, at the outlet side of the end part to be rolled of a blank pipe, in a circular arcuate shape along the axial direction of the pipe. CONSTITUTION:A rolling device for reducing the wall thickness at the end part of a seamless pipe is constituted of a mandrel 13, which is inserted in the inside of the end part of a blank pipe 6 to support the pipe 6, and a rolling roll 14B which rotates to subject the pipe 6 to rolling reduction in its radial direction and revolves around the pipe 6 at the same time while being in rolling contact with the outer circumference of the pipe 6 mounted on the mandrel 13. The pipe 6 end 6A is formed into a circular arcuate shape by gradually reducing the outer diameter, of the end part 6A to be rolled of the pipe 6, in a smoothly curved shape along the axial direction of pipe 6 with the aid of the rolling roll 14B. |
