| 摘要 |
Method of welding aligned aluminum torque tube components, comprising (i) defining a stepped square-butt joint to be welded by preforming the ends of said torque tubes and assembling such ends together in the nested condition; (ii) establishing an electrical direct current arc between a positive consumable aluminum-based electrode and said joint as cathode, the arc being shrouded in a shielding gas consisting, by volume, of 2-5% oxygen and the remainder inert gas, the current to the arc being pulsed at a frequency of 40-60 cycles per second while maintaining an average current of at least 200 amps; and (iii) while holding the pulsed arc in a predetermined orientation (i.e., position angle 45-60.degree., lead angle 5-15.degree., transverse angle 12.degree.) to the joint, moving the arc along the joint in a single pass at a relative speed of at least 60 inches per minute.
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