| 摘要 |
PURPOSE:To omit processing such as heating and piercing by continuous rolling of a pair of ingots cast continuously in parallel in such a manner that they form annular sectional shape by superposition, and joining and fastening the faces of superposition. CONSTITUTION:A pair of ingots 2A, 2B having small deformation resistance that come out from a pair of molds 1A, 1B of a continuous casting machine are rolled continuously while guiding to move on toward each other. Facing inner faces of ingots 2A, 2B are made concave and opposite outer faces are made semicircular by grooving rolls 3 and outer periphery forming rolls 4. Facing inner faces of the concentric semicircular billets 10 are superposed and joined so as to make the sectional form concentric circles. Thus, a cylindrical billet 21 can be obtained simply, and a seamless steel pipe is manufactured from the billet 21. |
