| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the lower of yield from being lowered by defective heat treatment of a seam part with a simple structure even in the case of a tube with a specification to the toughness. SOLUTION: A seam heat treatment device 21 arranged at the downstream side of a welder in the electric resistance welded tube manufacturing line and water-cooling nozzles 23 arranged just after this seam heat treatment 21 are constituted so as to be shiftable to the front and the rear sides along the flowing direction of the electric resistance welded tube manufacturing line. Further, as necessity requires, the seam heat treatment device 21 and the water cooling nozzle 23 are constituted so as to be shiftable to the advancing direction and the direction crossed at the right angle of the electric resistance welded tube manufacturing line.</p> |
