| 摘要 |
<p>The can formed by overlapping the edges of a piece of sheet is passed between two electrodes whose terminals receive a permanent continuous current of sufficient amplitude to increase the temp. of the joint to a value just below the melting point. Current impulses of amplitude sufficient to increase the temp. to the melting point are superimposed on this continuous current to provide a line of contiguous welds along the joint. The frequency of the impulses is above 1 kilocycle.</p> |
