The influence of corrosion on the fatigue strength of joined components from coated steel plate

Coated steel sheet is increasingly being used in various industries for products subjected to corrosive attack. Simultaneously, the importance of joining these materials is also increasing. This production step generally involves a damage to the protective coating. In the past, the primary aim was the protection of the unprocessed material. Today, however, awareness regarding the influence of corrosion in the joint area and its effect on the load-carrying properties of the joints is becoming increasingly acute. In the automobil industry, fatigue behaviour is one of the most important evaluation criteria. This paper reports on the influence of corrosion, partly in combination with mechanical loading, on the fatigue behaviour of spot welded, self-pierce-riveted, clinched, weld-bonded and clinch-bonded joints. The main aim of these investigations was the development of a suitable accelerated test which would allow the simulation in the laboratory of the various corrosive processes and long term loading as experienced in the field.