Advanced high strength steels (AHSS) have been continuously developed and are increasingly adopted in car body manufacturing. The weldability of different steels is also different from each other resulting in changing process windows. With simulations and optimizations by SORPAS® 2D.welding, it is possible to evaluate the process windows and splash limits of different steels for setting up or improving the real welding processes.
In this post, we present a case study on the relation between the strength of steel and the process window.
Material selection
Four types of steels were used in the simulations – DC06, HSLA340, DP600, and USIBOR1500. For direct comparisons of weldability between different steels, all sheets were welded with a thickness of 1.0 mm and GI coating.
Simulation setup
- Welding machine & time- AC spot welding machine, 300ms
- Simulation mode – Generation of weldability lobe with Current & force
- Current range for weldability lobe – 4.5kA to 11.5kA with an increment 0.25kA
- Force range for weldability lobe – 2kN to 5kN with increment 0.4kN
Process window and strength of steel
The general trend of splash limits for spot welding two steel sheets of thickness 1.0 mm:
- The splash limit moves toward a higher current with a larger weld force.
- The splash limit moves toward a lower current for steels with higher strength.
For complex weld combinations of mixed materials, different sheet thickness and more than two sheets, please contact us.
