The ultralight steel bodywork of future cars
The very latest steel grades enable us to reduce the weight of cars. This has a direct impact on fuel consumption and the emission of exhaust gases. Since the bodywork is a car’s heaviest component, in environmental terms it is very significant to make it lighter.
Over the years, the intensified crash requirements and the demand for more comfort have rather increased the weight of cars. The latest models have improved standard equipment, increased sound insulation, and to improve the durability of the car in the event of a crash, steel bars and fortifications in the car structure. These elements all increase the weight of vehicles.
A worldwide consortium of steel companies, including ArcelorMittal Gent, has achieved a breakthrough in bodywork design: ULSAB or Ultra Light Steel Auto Body. It is a lighter and yet stronger steel structure for the so-called “body-in-white”, that is, the bodywork without the closing parts, so without doors, boot lid or bonnet. The prototype developed by ULSAB for a medium-class car weighs only 203 kg, which is 25% less than the weight of comparable “bodies-in-white” made of conventional steel.
To save even more weight, the steel sheets that make up the sandwich material (consisting of a sandwich of a steel sheet and polyethylene) have been made extra thin within the ULSAB project. Sandwich panels are used mainly for acoustic insulation, for instance between the bonnet and the passenger compartment.
The reduction in weight offers a number of significant advantages in terms of environment-friendliness during the entire life cycle of the vehicle, from the extraction of raw materials and steel production to the manufacture of the vehicle, fuel consumption during the actual use of the car and subsequent recycling. In 2005, the ULSAB project was presented with the Stars of Energy Efficiency Award of the American Alliance to Save Energy, an organisation that negotiates with governments and captains of industry around the world to reduce energy consumption.
A further environmental benefit is the fact that there are secondary weight savings in other parts of the vehicle. The ULSAB technology has prompted sister projects such as ULSAC (Ultra Light Steel Auto Closures) and ULSAS (Ultra Light Steel Auto Suspensions), which focus on the closing parts and suspensions respectively. By using high-strength steels also at a lower level, ArcelorMittal Gent has succeeded in further reducing the total bodywork weight of modern vehicles.