When you hear the phrase “high-strength steel,” what immediately comes to mind? Is it the capability for lightweighting? How about its recyclability? Or how new technology is making sweeping changes in the steel industry?
Despite all of those being true, it probably wasn’t your first thought.
In 1951, a promising Mercedes-Benz engineer named Béla Barényi registered patent DBP 854.157 with the German patent office. This patented the concept of the “crumple zone,” where a vehicle’s body is designed to absorb impact in certain areas to reduce damage to the passenger compartment. This is done through a mix of materials, placing milder materials in areas away from passengers and protecting them by design. First used on the 1959 Mercedes W111, the concept was a significant break from general practice at the time, which was to make every exterior vehicle component stiffer. A completely stiff vehicle doesn’t absorb any impact, meaning passengers would feel the brunt of the impact generated by the collision. The crumple zone revolutionized the automotive industry’s approach to passenger safety and like many of Barényi’s innovations it’s still in use today.
Today’s crumple zones far outpace the safety and protection offered in those vehicles for a number of reasons. Though designs and technology have come a long way since the 1950s, the development of new steel grades has propelled the industry forward in its pursuit of safety. The latest grades of steel, known as advanced high-strength steel (AHSS), are up to five times as strong as previous grades and enable parts up to 35 percent lighter than the parts they replace. The high elongation (ability for the steel to be formed into parts despite its stiffness) and high-strength contribute to AHSS’s ability to absorb more energy as it deforms.
As regulations have made vehicle lightweighting a necessity, automakers are touting their use of high-strength steel in a vehicle’s construction. For example in larger, family-oriented vehicles like the 2017 Chrysler Pacifica, which features a body comprised of more than 72 percent high-strength steel.
The strongest steels have generally been placed in critical components of a vehicle’s passenger compartment. The passenger compartment surrounding the people inside includes the A- and B-pillars, roof rails and floor cross-members. Using high-tensile strength steel in these areas best protects passengers in the cases of rollovers and impacts to the front and side.
With more than 200 steel grades available, OEMs have the opportunity to utilize various grades throughout a vehicle. This allows automakers to use the right grade in the right application for exceptional occupant protection, crash energy management and durability. Knowing that AHSS is the fastest growing material in automotive applications, the steel industry continues to work closely with its customers to develop innovative grades and manufacturing technologies to provide tailored solutions for each application throughout the vehicle.
Do you know how much high-strength steel is in your vehicle? Let us know in the comments – we’d love to chat!