| 摘要 |
PURPOSE:To weld a thick joint of >=20mm. with a high efficiency by a conventional groove dimension by specifying a phase shift of a current flowing in an electrode of each pole, in case of AC three electrodes submerged arc welding. CONSTITUTION:The primary wiring of power sources 5, 6 of the first - the third pole power sources 5-7 is as before, but a current IM flowing in the second pole lags to a current IL flowing in the first pole by a phase difference of 90 deg.. Also, the primary side of the power source 7 is brought to wiring so as to become a reverse input to the power source 5, and a current IT flowing in the third pole is set to an opposite phase to IL. As a result, a heat input of a large current arc of the first pole 12 is spent efficiently for melting a base metal which is still cold before welding, and a remarkable deep penetration can be expected. Also, a swing of an arc of the second pole 13 becomes remarkably small, a molten pool 20 is put in order by inclining the second and the third poles 13, 14, and an effect for forming a good bead is promoted. Also, the arc of the poles 13, 14 and a transfer phenomenon of particles from an electrode end are stabilized. |
