“The combination of these two effects significantly increases the strength of the material and delays component failure under dynamic load. In addition, the forming capacity and energy absorption capacity improve considerably in the event of an impact” explains Nadine Lehnert, project manager at Fraunhofer IWU.
The process chain begins with a coarse-grained casting blank. In cold forging, this is partially martensitically strengthened by impact extrusion. Subsequent heat treatment converts the martensite back into fine-grained austenite. This structural-mechanical control allows a targeted improvement of the component properties.
Wide range of applications in safety-critical areas
The new alloy is suitable for a wide range of industries thanks to its high strength, crack resistance and ductility:
- Automotive: Screws, chassis components, crash absorbers, and body structures could benefit from high energy absorption and crash safety.
- Aerospace: Structural components and fasteners can become lighter and more resilient with the new steel casting.
- Medical Technology: The strength and biocompatibility of implants and surgical instruments could increase.
Construction and Infrastructure: Mountain anchors and fasteners for bridges and tunnels would gain in safety thanks to enhanced crack resistance. The alloy excels where durability under extreme loads is crucial.
Energy-efficient cold forming as a production advantage
The new material is ideal for energy-efficient cold forming. This avoids costly heating processes such as preheating, rolling or descaling, thereby saving CO₂ and operating costs. At the same time, the process chain is significantly shortened.
“The cold forming process chain is significantly shorter and more efficient. We start with a pre-cast workpiece, which is then formed directly” says Lehnert.
