Generalized dynamic transition resistance in spot welding of aluminized 22MnB5

The purpose of this work is to provide generalized information on the transition resistance properties in spot welding of the aluminium-silicon-coated 22MnB5 steel sheet for varying mechanical and electrical contact loads. As the transition resistance is a prominent influence factor on the magnitude of heat release in the process, it is crucial to have in-depth information on it at hand in order to optimize the mechanical properties of the weld by choosing appropriate process parameters. Based on resistance measurements, a numerical simulation method was employed in order to determine the specific transition resistance as a function of temperature and contact pressure. A mathematical formulation of the results is provided. At the sheet-sheet contact, the specific transition resistance was up to ten times higher than at the electrode-sheet contact. Additionally, it was shown that the local contact temperature is the largest influence factor on the specific transition resistance.