| 摘要 |
<p>Device for joining workpieces by submerged arc welding uses a continuously moving row of consumable electrodes forming arcs, pref. in a common weld pool, plus a drive unit to produce relative motion between the workpiece and the electrodes and circuit elements connecting the workpiece and the electrodes to separate phases of a multiphase alternating current (A.C.) source. The novelty is the use of four electrodes, the first two and the last two being connected in pairs to sec. windings of two pairs of transformers with a Scott connection, the starts of the first and fourth sec. windings being connected to the first and fourth electrodes whereas the ends of the second and third sec. windings are connected to the second and third electrode, the remaining connections on the windings being linked to the workpiece. Large dia. pipes with wall thicknesses up to 40 mm can be welded at speeds of e.g. 1.3 m/min. E.g. the welding speed for 25 mm thickness is 1.2 m/min but with the invention 1.8 m/m can be achieved.</p> |
