| 摘要 |
PURPOSE:To improve the quality of a flux cored wire for welding in the stage of forming a band steel to a tubular shape, packing a flux therein, welding both ends of the band steel and producing said wire, by limiting the content of oxygen in the band steel and setting the area of wled metal in the tubular section at a specific value. CONSTITUTION:A band steel 2 of 8-100ppm content of oxygen is formed successively to a tubular shape with working rolls as shown by (a), (b), (c), and a flux F is packed therein from a hopper 3. The butted two end parts are sealed by TIG welding W. The tube is then passed through dies 4-1, 4-2, 4-3 and is drawn to a prescribed size, whereby a flux cored wire is produced. The weld heat input during the welding in this case is regulated and the wire is so welded that the sectional area ratio of weld metal with respect to the sectional area in the tubular metallic part of the wire attains 5-25%. Defects such as wetting of the flux occuring in the lack of the sealing property in the weld zone, and the leakage of the flux are prevented. |
