Investigation into the Effect of Spot Weld Electrode Life and Quality on the Corrosion Behavior of Galvanized Automotive Steel Using the Three-dimensional Scanning Vibrating Technique

Abstract

The Three dimensional Scanning Vibrating Electrode Technique (3D SVET) – which allows the measurement of non-planar samples - has been used to investigate the effects that spot weld tip lifetime (i.e. number of welds produced by a tip between dressings) has on corrosion of spot welded steel. Cathodic activity is concentrated within the spot weld when weld tips are fresh (used for <10 welds) or aged (>1000 welds) whilst anodic activity is found on the spot weld perimeter. This is due to copper deposition within the weld and zinc enrichment around the spot weld as a result of the welding process.