| 摘要 |
PURPOSE:To manufacture efficiently and economically a tube excellent in heat- transfer performance by feeding a skelp, having multiple lines of grooves formed in its one-side surface by hot rolling, into a welded pipe manufacturing line after finish cutting the grooves and forming it into a tube. CONSTITUTION:After heating a skelp 1 by passing it through the inside of an induction coil 4 of a high frequency induction heating device, multiple lines of grooves 2 are formed in the one-side surface of the skelp 1 along the flow direction of the skelp 1 by a mill provided with a grooved formrolling roll 7 and a flat roll 5. After once cooling the skelp 1 having the grooves 2 by passing it through a cooling line 11 successively, each root-corner RB part of the grooves 2 is formed into a sharp one by finish cutting the RB part with the aid of a rack cutter 8 of a cutting machine. Successively the finish-cut skelp 1 is fed into a welded tube manufacturing line such as an electric welded tube manufacturing installation 9, to form it into a tube 10; thereby obtaining a heat-transfer tube excellent in heat transfer performance, economically in high manufacturing speed. |
