The strength of steel determines the structural properties of the car's body, which is the driving force behind the steel industry's continuous development and innovation, and the discovery of the amazing potential of steel materials. World Auto Steel and its members are dedicating to promote the application of advanced high-strength steels (AHSS) in the automotive industry. Their project team launched a campaign called Steel Your World in September 2017. The event invited the global automotive community to participate in the video shooting, that guests from different perspectives introduced the steel especially AHSS to the public, to open a window for car design.
Thinner, stronger, safer
For decades, the steel industry has pioneered a whole new class of materials that are 50% stronger than their predecessors. At the core of this innovation lies the ever-growing AHSS family. No other automotive material compares to the variety of steel strength levels today.
This means that the steel can be made thinner, yet retain its strength for vehicle structure performance and safety. Thinner material means less material is used, and therefore components are lighter, contributing to vehicle weight reduction and reduced environmental emissions. Because primary manufacture of steel produces fewer emissions than any other automotive material, it’s a win-win, both in terms of reduced steel manufacturing and vehicle emissions.
These AHSS capabilities result from their unique combination of strength and ductility. AHSS are complex, sophisticated materials, with carefully selected chemical compositions and multiphase microstructures resulting from precisely controlled heating and cooling processes. Various strengthening mechanisms are employed to achieve a range of strength, ductility, toughness, and fatigue properties.
How carmakers use AHSS
Carmakers focus on improving safety, performance, cost and design, all at the lightest weight possible for fuel economy. While there have been debates in the past about the best lightweight material, AHSS is still on top. AHSS have high strength and can be reasonably thinned in the design and application of the car body, and can achieve a weight-reducing effect under safety ensuring. Automotive body engineers must contend with extreme demands of multiple and complex loading conditions vital to vehicle handling. They also must meet requirements for strength. Almost every new car that is presented features AHSS and is significantly lighter than its predecessor.
Here are brief summaries about a few of them.
The strength of steel is found in the 2017 Jeep Compass, which includes a “safety cage” construction with more than 65 percent high-strength steel.
The 2016 GM Chevy Malibu shows off a stronger, lighter body structure that contributes to its efficiency and driving dynamics. Greater use of high-strength steels enabled engineers to design the body structure with thinner components in some areas, delivering comparable crash performance with lower weight.
The body structure of the new Kia Sportage redesign includes 51 percent AHSS, compared to only 18 percent for the car model that are no longer produced. It significantly improving the body structure and also increasing torsional rigidity to 39 percent.
The 2018 Honda Accord, winner of the 2018 Car of the Year, body structure is lighter and more rigid, utilizing 29 percent Ultra High-strength steel, the most extensive application of this weight-saving material in any current mass-produced Honda car. Overall, the new Accord employs 54.2 percent High-Strength Steel (above 440 MPa).