PRODUCTION OF LASER BEAM WELDED STEEL TUBE

摘要

PROBLEM TO BE SOLVED: To provide a production method of the laser beam welded steel tube without deteriorating the property of a welded part and capable of high speed welding. SOLUTION: In a producing method of the laser beam welded steel tube, by which a part to be welded of a steel tube formed to tubular is laser beam welded, both inner/outer faces of the formed tube are welded. A laser beam used for welding is preferably emitted from either a chemically induced oxygen iodin laser beam oscillator or a YAG laser beam oscillator and is transmitted through an optical fiber. Further, as necessary, a part to be welded is preheated before welding by high frequency heating and/or a seam part is heat treated after welding.