Resistance spot welding with variable electrode force-development and benefit of a force profile to extend the weldability of 22MnB5+AS150

Abstract

Compared with conventional steels, press-hardened steels with an aluminium-silicon coating have a smaller welding range, which is resulting in reduced process stability. For this reason, an analytical methodology is required, which can optimise the welding parameters and extend the welding range significantly. Consequently, most publications focus on the variation of welding time and welding current at a constant electrode force. This paper deals with the design of a force profile to improve weldability and joint quality. The basis for this investigation is the identification of significant characteristic values by the recorded process signals.