inated in the i3. Tesla, too, is reducing the share of aluminium and titanium in its model 3 in favour of steel. The European steel industry is now able to supply ultra high-tensile yet light and formable steels. They score with their ease of processing, the homogenous surface for painting, higher raw material availability, and their ability to be combined with other materials.
“The share of high strength steels amongst the steel grades used in vehicle construction will rise from its current level of 18% to 30%,” says Jan Kleibrink of the Handelsblatt Research Institute, citing preliminary work by the Posco Research Institute. According to the World Steel Association (worldsteel), this would allow vehicle weights to be reduced by between 25% and 39%, leading to potential savings of 3 tonnes to 4.5 tonnes of greenhouse gas emissions over a vehicle’s service life. Rather than disproportionately expensive weight reduction, the trend is now towards achieving a balance between weight and costs by using a mix of different steel grades with aluminium and plastic surfaces.
Irrespective of the material used, absolute priority is given to the safety of a car body in the event of an accident. That’s why, to date, a combination of aluminium and steel has been used. New steel grades have 3 to 4 times the tensile strength of conventional steels, making them particularly suitable for use in safety relevant areas, as the study shows. voestalpine is regarded as a technology leader in the production of ultra high strength yet increasingly lightweight body parts which ensure passenger safety while helping to significantly extend the electric vehicle range by reducing the overall weight.
Steel components in the electric motor and drive
The HRI study examined the choice of materials in the electric motor as well. The outcome is that steel also plays a crucial role in the motor and drive. Between 40kg and 100kg of so called non-grain-oriented electrical steel are used in the construction of a purely electric vehicle. That could increase demand for this magnetically-soft material to over a million tonnes a year in Europe alone, depending on demand. Steel manufacturers are focusing on making these electrical steels tougher and thinner in order to reduce the weight of the motor.
As the physical limits in this field have almost been reached, in future manufacturers will differentiate themselves primarily through their expertise in bonding, joining, and forming technologies. In addition, special alloys with a higher silicon and aluminium content reduce heat loss in the motor during magnetic reversal by up to 30%. Manufacturers able to demonstrate expertise in this segment will secure themselves an excellent starting position in the growing electromobility market.
Battery protection: Attractive field of activity for European steel manufacturers
Three quarters of batteries are currently manufactured in Asia, the study confirms. For European industries, this means a lack of expertise and of access to sufficiently established value chains. Not so for the housing: The battery elements need a correspondingly large container which offers sufficient protection in the event of a crash and prevent substances from leaking after an accident.
Battery casings are a new field of activity for European material manufacturers, and also for voestalpine which offers particularly lightweight and secure battery housing solutions. As the battery module as a whole can account for up to 40% of a vehicle’s weight, in addition to the safety aspects, such criteria as weight, cost-effectiveness, and sustainability are all considerations in material selections. In contrast to aluminium, titanium, and fibre composites, steel has the advantage of a superior ability to withstand distortion during accidents.
The advantages of steel for climate protection
Climate protection is the key driver of electromobility. However, if fossil fuels are used in the production of aluminium or carbon, and where the electricity in charging stations is not generated from renewables, the carbon footp