**Acknowledgements**

The present contribution is a part of the AiF project IGF-No. 20.616 B/DVS-No. 01.3145 of the German Research Association on Welding and Allied Processes (DVS). It was kindly supported by the AiF (German Federation of Industrial Research Associations) within the program for promoting the Industrial Collective Research (IGF) of the Federal Ministry for Economic Affairs and Energy (BMWi), based on a decision by the German Bundestag.
