Four-electrode submerged arc welding process.

摘要

A four-electrode submerged arc welding process employs connections of four electrodes aligned in one row for alternating current source so that electromagnetic force Fx₄ in a direction opposite to a welding direction acting upon a middle point of the arc from the rearmost electrode is within -25≲Fx₄≲-10 (N/m). The connections are preferably selected such that phase differences among currents applied to the three electrodes other than the frontmost or rearmost electrode are 120°, respectively, and a phase difference of the remaining frontmost or rearmost electrode is within 0°±30° relative to the furthermost electrode.

With such connections of the four electrodes, the four-electrode submerged arc welding process remarkably prevents welding defects such as undercuts even at higher welding speeds.