Automotive manufacturers are increasingly demanding stronger yet lighter components. The response of the steel industry is a consistent focus on lightweight construction. A view of its future.
Electric vehicles are the height of fashion, and are also encouraging today’s search for lightweight construction solutions. For the heavier its body, the shorter the distance a battery-powered vehicle can travel. A simple calculation really.
The lightness of steel
It was three years ago that the strategy consultants at Berylls forecast 400% growth in the market for lightweight automotive components to 2025. “Five or ten years ago a lot of money was invested in all forms of lightweight construction,” remembers Enno Arenholz (Head of Preliminary Research/Technology/Innovation, voestalpine Stahl GmbH). “Today suppliers and automotive manufacturers are all focusing on affordable lightweight construction, and here steel enjoys excellent prospects.” The costs for saving a kilogram of vehicle weight are much lower for steel than for aluminum.
Costs for saving 1 kg of vehicle weight:
- Steel: approx. 2 euros;
- Aluminum: approx. 4 euros;
- Carbon-fiber-reinforced plastics (CFRP): approx. 10-30 euros.
For vehicles in mass production, manufacturers will accept a cost of around 5 euros for each kilogram of weight saved—a clear factor favoring steel. To date lightweight construction involving the intensive use of aluminum, magnesium, titanium, or CFRP has been limited to special models and concept vehicles. Manufacturers continue to rely on ultra high-strength components made from steel for volume cars; in a VW Golf 7 they make up 28% of the body in white!
The strenght of steel
"The strength of future steels will determine their role in future cars."
Stronger steels means components which are at least as stable, but even thinner and therefore lighter. “Although the Max Planck Institute is currently studying steels with a strength of 7,000 MPa, we are at the 1,800 MPa level and looking forward to reaching the 2,000 MPa mark.” However, these research results indicate steel’s potential for lightweight construction. Another great plus for steel in the car of the future is its excellent environmental balance in life cycle assessments.
Ingo Olschewski, Senior Manager for Strategy and Consulting at the Forschungsgesellschaft Kraftfahrwesen mbH Aachen (fka), also highlighted the productive efficiency of steel in lightweight construction at the 11th voestalpine synergy platform.
"Lightweight design using modern steel applications will continue to play a role in electric cars. For instance, it improves driving dynamics, which in turn meets customer demands for greater driving comfort and safety."
With technologies such as hot forming press-hardened steels in an indirect or direct process, with phs-ultraform®, phs-directform®, as well as phs-rollform®, voestalpine is excellently equipped for the future of high-strength lightweight automotive construction.