Answer:
Yes, it is possible to select high-strength steel SAS 670 for nonlinear design in RF‑CONCRETE Members. This way, you can perform stability analysis for columns, among other things. The steel can be selected in the Materials section of the add-on module (see Image 01). Since DIN EN 1992‑1‑1 only allows fyk = 500 N/mm² by default, this limit must be adjusted when using SAS 670.