After years of research and hundreds of designs, ArcelorMittal has developed a new ultra lightweight car door that's expected to improve fuel efficiency.
ArcelorMittal researchers, including engineers at the company's research and development center in East Chicago, spent three years working on the new lightweight car door, which weighs 27 percent less than existing steel car doors. The steelmaker expects to be able to shave up to 34 percent of the weight of the car doors once new grades of high-strength steel come to market in the next few years.
The new design should help automakers comply with the federal fuel economy standards that mandate vehicles average 54.4 mpg by 2025.
Automakers have been considering using aluminum and other metals to reduce the weight of vehicles so they burn less gas. Steelmakers have been trying to counter by developing lighter grades of steel.
Company officials are hailing the innovation as a breakthrough milestone. They also say their alternative is cheaper than car doors made with the rival metal aluminum.
"By applying the present solutions, a car door can be 30 percent less expensive than an aluminum door," said Greg Ludkovsky, vice president of global research and development. "Innovative steel solutions like the ultra lightweight car door solutions are further proof that steel is by far the most sustainable, the most versatile and the most affordable material to help carmakers produce lighter vehicles and achieve their weight-reduction targets on time."
ArcelorMittal's Northwest Indiana facilities already are making the high-strength steels that will be used in the new door design, said Blake Zuidema, director of global research and development for automotive product applications.
Locally, ArcelorMittal operates integrated steel mills in East Chicago and Burns Harbor, a global research and development facility in East Chicago, a hot strip mill in Riverdale, a plate mill in Gary, and processing and finishing joint venture facilities in New Carlisle.
The steelmaker developed the ultra lightweight car door to help automakers meet future fuel-efficiency regulations so they don't turn to aluminum or carbon fiber, Zuidema said.
"We're leading the fight for the steel industry against the use of aluminum in cars," he said.
New tailpipe emission rules will come into effect in Europe in 2015, and emission and fuel economy regulations are set to begin in the United States in 2021. Even tougher standards are being contemplated both in the U.S. and abroad.
Automakers have been studying every part of the vehicle to see where weight can be reduced. A gram of carbon dioxide emissions is saved for every 12 pounds the vehicle weight is reduced.
ArcelorMittal has been in talks with major automakers about incorporating the lighter car door design in future vehicles, Zuidema said.
The company's researchers went through more than 1,500 design iterations with the ultra lightweight door, which reduces the weight of a door from 40.3 pounds to 29.3 pounds. Use of the new design on a four-door sedan would save an estimated 2.7 grams of carbon dioxide-equivalent emissions per mile.
"We went through 1,500 design iterations, which basically means we came up with 1,500 different door designs," Zuidema said. "We talked to some of our friends in the auto industry, and no one can think of a component that underwent so many design iterations. This might be the single most highly engineered automotive component ever."
The door uses a mixture of advanced high-strength steels and ultra-high-strength steels, and achieves weight savings partly by using a thinner steel for the outer door panel. Though thinner, the outer panel is still strong enough to pass industry standards for dent resistance and is just as safe as existing steel doors, Zuidema said.
Steelmakers have been trying to come up with an answer to aluminum and other metals that automakers have been looking toward as a way to make more fuel-efficient vehicles, said New York-based steel industry analyst Charles Bradford. They have been trying to keep the business because the automotive industry currently accounts for about 20 percent of their demand.