P 217 - Corrosion behaviour of joints made of surface-finished sheet metal

Uncoated cold-rolled strip, hot-dip galvanised sheet metal, Galvannealed and Galfan were used. The materials were joined to themselves using the following joining methods: MAG, laser and resistance spot welding, MIG soldering, pressure joining and hemming. The results show that regardless of the corrosion test method, red rust occurs preferentially in the joining area. However, it is not possible to draw any conclusions about the actual strength of a corroded joint from this visual appearance of corrosion. A direct comparison of the materials with each other is also only permissible to a limited extent, as the corrosive media used attack the materials differently due to the prevailing corrosion mechanisms. However, each corrosion test method can be substituted on its own for quality assurance purposes. Statements about the corrosion behaviour of thin sheets under practical conditions are more likely to be obtained by combined test methods. The investigations also show that in the case of joined thin sheets, the positioning of the joining area in the test must be carried out in accordance with the position on the object intended by the designer. Studiengesellschaft Stahlanwendung e.V.