Electric resistance seam welding of can bodies - using lap joint with controlled width and two filler wires

摘要

In a process for the semi- or completely-automatic electric seam welding of thin sheet metal, which may be Sn- or Zn-coated, surface treated, or be black cold-rolled steel strip, using a lap joint where the overlap is smaller than the electrode width, the novelty is that the width of the lap joint is 3-6 times the sheet thickness, and flat electrode filler wires are used with width 2-3 times the width of the lap joint. A Z-shaped guide rail is employed to reduce the overlap to the required amt. at the point where welding occurs, guides or the electrode rollers ensuring the correct overlap. The flat filler wire pref. has thickness:width ratio 1:2.5-4.5.