At the IMechE "Lightweighting for carbon-free vehicles" conference, which took place on 23rd April at the Jaguar Assembly Plant in Birmingham, Professor Jon King, Director of Corus Automotive Engineering, explained that steel continues to remain the preferred body structure material for vehicle construction, used in 99% of all new cars in 2007.
Delegates heard that, although the average vehicle is now 50% heavier compared to 40 years ago, the use of Advanced High Strength Steels (AHSS) has provided solutions for cost-effective lightweighting on vehicles over the last 10 years or so, making them up to 60kg lighter, despite the huge improvements in structural safety. Further weight savings due to AHSS deployment are now being realised on many recently launched vehicles, which can equate to a saving of more than one tonne of CO2 over the vehicle’s lifespan.
The forthcoming EU legislation is proposing a 20% reduction in today’s CO2 levels, down to 130 g/km in 2012, with penalties for non-compliance by the vehicle manufacturer determined by a weight-based sliding scale. This switches the focus firmly towards cost-effective lightweighting measures to complement the efforts being made on powertrain efficiency and aerodynamic improvements. Professor King described the range of AHSS technologies and their attributes that makes steel the most cost-effective material for achieving weight savings in mass production applications.
As a natural consequence, material selection is assuming a greater priority in the vehicle development process. Choices need to be made early as they have a fundamental effect on vehicle architecture and manufacturing assumptions. At a detailed level, the development and use of advanced simulation tools is crucial, as the need for optimisation instead of compromise assumes greater and greater importance.
In his conclusions, Professor King explained: “These results are significant, with steel continuing to be the benchmark material in vehicle body construction. Looking forward to further technological developments and improved collaboration between vehicle manufacturers and their supply chains, huge possibilities exist for additional weight reduction and innovation, as the automotive industry faces increasing pressure and legislative measures to reduce emissions beyond 2012.”