Expect to see more body-in-white and other vehicle applications using advanced high-strength steel (AHSS) in future model years.
Examples of advanced steels in the 2015 MY include six different HSS grades for the Acura TLX sedan’s body structure (read more at http://articles.sae.org/13444/), the Chevrolet Colorado and GMC Canyon midsize trucks using more than 70% HSS in the body structure, and the Chrysler 200 midsize sedan with more than 60% AHSS content in its frame.
“Advanced high-strength steel is a continuum. We’ve been working on AHSS for more than a decade. They have evolved. The materials that are available today are not yet fully adopted by our customers, and that’s because the vehicles are redesigned every five to seven years. So that’s the entry point where you can do a full redesign and take advantage of these new materials,” said Lawrence Kavanagh, President of the Steel Market Development Institute (SMDI).
Kavanagh and Michael Williams, Senior Vice President–Strategic Planning & Business Development for United States Steel Corp. and the Chairman of SMDI CEO Group, were interviewed by Automotive Engineering during media days at the 2015 North American International Auto Show.
Various SMDI forums are designed to help engineers understand AHSS, in particular how these next-generation steels can be formed and welded. The goal is to put AHSS on an application track to assist automakers in achieving fuel efficiency, safety, and performance targets “without having to incur the cost penalties of alternative materials,” said Kavanagh.
Several concept studies address the benefits of using AHSS.
SMDI and WorldAutoSteel’s FutureSteelVehicle (FSV) project showed how AHSS can enable a five-star crash safety rating, reduce total lifecycle emissions, as well as reduce mass and emissions without a cost penalty. FSV’s proposed 2015 to 2020 MY vehicles are battery electric and plug-in hybrid electric for A- and B-Class vehicles as well as plug-in hybrid electric and fuel cell for C- and D-Class vehicles. The FSV case study spotlighted more than 20 new AHSS grades expected to be commercially available between 2015 and 2020.
An SMDI long products study with parts manufacturer Mahle identified opportunities for using advanced lightweight steel for engine parts, such as connecting rods, crankshafts, camshafts, and pistons. Other SMDI projects have spotlighted using steel for liftgates, doors, outer body panels, wheels, bumpers, and fuel tanks.
While chassis, body architecture, and outer panels remain the prime production application areas for steel, other materials are vying for a piece of the vehicle pie.
The aluminum alloys used throughout the 2015 Ford F-150’s body, marking a first for the full-size pickup truck, is one of the more notable examples. “The frame of that vehicle is actually AHSS, and it’s a very good use of advanced steel by the Ford design team,” said Kavanagh.
Material competitors will always be part of the business landscape.
“Competition can be good, and it really brings focus to your efforts to support an industry that’s very important, like the automotive industry. So we’re accelerating our innovation, we’re accelerating our product design, we’re accelerating our investments to be able to manufacture the products that will deliver a higher-value material solution than those other materials,” Williams said.
For more on AHSS developments, read this recent Q&A with ArcelorMittal's VP of Global R&D: http://articles.sae.org/13781/