Spot welding is the most applied resistance welding process for joining sheet metals. It has been used for many years in many industries. The fusion joint is produced by pressing pointed electrodes at the location to be welded in order to position the current and heat generation. The weld nugget size is largely dependent on the electrode tip contact area.
It is the predominant joining process for assembling car bodies and large components in the automotive industry. At the same time, the aerospace industry uses this method for interior components. Also widely used for manufacturing of furniture and domestic equipment etc.
The focus on high quality and developments quickly to the end-user, means that spot welding issues need to be solved quickly and in a cost-efficient way.
Spot welding problems
The commonly encountered problems include the following:
- expulsions (splashes or spatters)
- electrode degradation
- electrode misalignment
- shunt current loss between welded spots
- cold weld (or false weld) especially in spot welding of multiple sheets
- spot welding of dissimilar metals such as between aluminum and steel sheets
- electrode indentation on sheet surface at the welded point
- surface coatings
- surface oxides and contact resistance
- dynamic resistance
The solutions for problems
The most cost-efficient way to solve these problems is to work with simulations in combinations with a real live test. You need to focus on:
- optimization of the spot welding process
- interactive CAE design with real welding process conditions
- welding simulation enhanced artificial intelligence
You can optimize the process in a short time with software, whereas if you need to guess based on your experience it may take a lot of time and material before you have reached your goal.