RESISTANCE SEAM WELDING

                           RESISTANCE SEAM WELDING

the resistance seam welding[RSEW] is a specialised process of spot welding.there the cylindrical electrodes are replaced by disc. electrodes are continuously rotated so that the workpieces get advanced understrength the at the same time the pressure on the joined is mounted the electrodes need not be separated at any time.the current is applied through the heavy copper electrodes in a series of pulses at proper intervals the timing is adjusted so that the pulses overlap each other and thus, form a continuous seam joint .if the timing of the pulses is increased then each of the weld formed would not overlap giving in intermitted seam.

                                     to achieve the pressure tightness the seam weld should at least overlap 10 to 25% of each nugget.

types of seam welding

1. continuous seam welding: continuous- they are as continuous if each individual spot overlaps the proceeding.one making a gas are liquid-press tight weld

2. intermitted seam welding: -they are said to be intermitted, if each individual weld, increment making a joint which has good mechanical strength but is not press tightly

3.lap seam welding: - it is the  most commonly  used in the seam welding it in this welding the peace or the edges to be are lapped sufficiently to be present are lapped sufficiently to prevent expulsion of molten metal from the edges of the workpiece