Stringent fuel-efficiency standards have pitted steel against rival metals in a race to make cars, trucks and SUVs lighter.
The stakes are high, an ArcelorMittal official warns.
If automakers were to replace steel wholesale with aluminum or other lightweight metals, mill closures and economic devastation would result, said Blake Zuidema, director of automotive product applications.
ArcelorMittal believes it has designed enough lightweight auto components and developed enough advanced grades of high-strength steel to help automakers reach the federally mandated average mileage of 54.5 mph. But automakers will ultimately decide whether they continue to make car frames and other parts with steel, or switch to aluminum, carbon fiber composite, magnesium or other metals.
"What's at stake is 15 million tons of flat rolled steel that goes to the automotive market," Zuidema said during a recent tri-state summit on regionalism at the Federal Reserve Bank of Chicago. "That's three big steel mills. The economic devastation would be unthinkable."
ArcerlorMittal's Northwest Indiana mills are heavily focused on the automotive industry, spokesman William Steers said. U.S. Steel's Gary Works and Midwest Plant in Portage also serve automakers.
"Much of the steel in the tri-state area is for the automotive market," Zuidema said.
The Luxembourg-based steelmaker, the largest in the world, has been working on new automotive component designs to preserve steel's place in cars, the steel industry's share of the automotive market, and jobs at its mills, he said.
"When they announced the new fuel economy regulations that would require the allowable tailpipe emissions to essentially be cut in half by 2025, every proponent of alternative metals was jumping for joy," Zuidema said. "They said it was game over for steel."
But the steel industry has risen to the challenge and come up with ways to reduce the weight in vehicles while using less steel, Zuidema said. Honda recently started using one of the ArcelorMittal's lightweight designs in its Acura MDX. ArcelorMittal and other steelmakers also have been making higher grades of steel that are just as strong but weigh less.
About 15 percent of the steel that goes into cars is now advanced high-strength steel, Zuidema said. Eventually, as much as 65 percent could be the higher grade.
Steelmakers hope automakers will stick with the heavier metal, which Zuidema said is cheaper and can be made in a more environmentally friendly way than aluminum or other rival materials.
"We are lightweighting products to close that gap to 54.5 mph and we can get there," he said. "The cost of steel is lower than aluminum or carbon fiber. The life-cycle carbon emissions are lower because less energy is needed to make steel. Five times as much CO2 is released when making aluminum. It's 10 times as much with carbon fiber, and 15 times as much with magnesium."