A Study of Spot Welding of Plated Steel (Part 2)

The behavior of plated metal during spot welding

Abstract

Nickel, copper, chromium and tin plated steel in 1 mm thickness are spot-welded and cross sections of the welds are subjected to microprobe analysis to make clear the behavior of the plated metal during spot welding. The observation of macrophotographs and microprobe analysis elucidate that in spot welding of the nickel, copper and chromium plated steel, plated metals mingle into the weld nugget under violent stirring motion of the fused metals, resulting in formation of homogeneous alloys in the short weld time (about 10 cycles) and that, on the other hand, in spot welding of the tin plated steel, tin is expelled from the weld interface because of its low melting point and it does not mingle into the weld nugget.