| 摘要 |
PURPOSE:To provide a method for manufacturing welded tube by composite heat source by which increase in thickness is provented at the pressure weld part of a metallic strip. CONSTITUTION:In order to impart an upset quantity more than an adequate quantity to a metallic strip 7 at the time of normal welding, an inter-roll gap is set between squeeze rolls 1. In the early stage of the welding, the movement of the upper flange of the squeeze rolls 1 is detected by a gap sensor 4; through a controller 6, in order to make the inter-roll gap constant which fluctuates in accordance with the temp. rise of the end faces 8 of the metallic strip 7, a moving mechanism 1a is moved to make the upset quantity to the metallic strip 7 constant, and the pressure weld part is irradiated with a laser beam 3. Then, when the weld temp. reaches an optimum value through a two-color pyrometer 10, this control is completed, and the inter-roll distance of the squeeze rolls 1 is set to an adequate upset quantity to perform the welding. |
