| Abstract: | The objective of this study was an evaluation of the influence of the type of coating on the working life of electrodes when spot welding interstitial free steels with heat immersion coatings of the Zn pure (GI) and Zn–Fe alloy (GA) types. To do so, the electrode life was determined and the behaviour of the Zn of the coating evaluated on the contact plate/electrode surface during its working life, using ESM/EDS. As a result, it was confirmed that the working life of electrodes when welding GA steel was much higher than with GI steel. The electrode life was shown to be dependent on the fusion point of the coating. With the GI steel, part of the zinc layer moves to the edge of the electrode/plate contact at the start of the working life of the electrode. With the GA steel, Zn displacement was not confirmed throughout the whole working life of the electrode, due to the high-fusion point of the coating. |
