Bodyshell as Key Safety Factor: Ultra-High-Strength Materials

Key aspects of the safety concept at the heart of Mercedes-Benz vehicles include intelligent design and meticulous material selection. More so than ever before, Mercedes-Benz has given preference to ultra-high-strength steel alloys because they offer maximum strength whilst minimising weight and, therefore, are essential for meeting the strict safety and durability requirements.

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Occupant protection: Mercedes engineers have continued to perfect the idea patented by their mentor Béla Barényi – through a programme of accident research, crash tests and computer simulations.

Around 72 percent of all the bodyshell panels for the Mercedes-Benz E-Class e.g. are made from ultra-high-strength steel – a new record in passenger-car development. These ultra-high-strength, high-tech alloys, which boast three to four times the tensile strength of conventional high-strength steel grades, account for around eight percent of the weight. They are used at points where the material can be exposed to exceptionally high stresses during an accident – as a material for the B-pillars and the side roof frames to provide side impact protection, for example, or at the rear to produce a robust crossmember.

If these sophisticated alloys were not used, far more material would be required in order to meet the stringent safety requirements. The B-pillar is a perfect case in point: the body components which have to absorb high forces and transfer these into the body structure in the event of a side impact consist of sheet-metal shells and an extensive reinforcement which reaches as far as the upper edge of the belt deflector. One of the shells and the reinforcement are made from ultra-high-strength, hot-formed steel. Were they made using conventional sheet steel, however, the B-pillars would be more than a third heavier. In other words, the ultra-high-strength, high-tech alloy enhances safety whilst also reducing weight.

Enlarge   The tridion safety cell is a hemispherical steel cage which encloses the interior of the car and also forms he bulk of the smart’s chassis. In smart vehicles, the tridion safety cell ensures optimum occupant protection. The tridion safety cell is a hemispherical steel cage which encloses the interior of the car and also forms he bulk of the smart’s chassis. A small energy-absorbing crumple zone at the front of the car cleverly lessens any impact.