A federal appellate court set aside a lower court's jury verdict Friday that partly invalidated a patent ArcelorMittal held on a type of steel product produced in Indiana that has automotive industry applications.
The U.S. Court of Appeals for the Federal Circuit in Washington said the federal district court made an error in determining the standard the jury used to judge whether products made by rival steel companies including AK Steel Corp. violated ArcelorMittal's patent. The court said in its opinion that language the U.S. District Court in Delaware used in its jury instruction improperly excluded products that could better determine if infringement occurred.
The appellate court remanded the district court to hold a new trial to analyze whether a broader range of products would violate the patent and if ArcelorMittal obtained commercial success in the automotive market with the steel made using the production process described.
In a partial dissent from the three-judge panel's majority opinion, Circuit Judge Evan Wallach supported ArcelorMittal's claim the patent protected a larger range of products based on their tensile strength than those the district court considered under the basis for infringement.
The patent covers boron steel sheet with an aluminum-based coating that is applied after rolling the sheet to its final thickness. In the United States, the company's integrated steel mills in Northwest Indiana supply the steel under the Usibor trademark.
"ArcelorMittal is pleased with the decision confirming its patent rights for this innovative technology and will continue to vigorously enforce and defend its patent rights against any potential infringement moving forward," said ArcelorMittal USA spokeswoman Mary Beth Holdford in a statement issued Monday.
The Usibor technology was created in France by one of the Arcelor predecessors.
Two ArcelorMittal French units sued AK Steel, Severstal Dearborn Inc. and Wheeling-Nisshin Inc. on Jan. 22, 2010, claiming the firms violated a U.S. patent held. However, the jury verdict returned on Jan. 4, 2011, found that West Chester, Ohio-based AK Steel and other defendants didn't infringe on the patent and that the patent was not valid.
AK Steel said in a statement Monday regardless of the outcome of the new trial, the appellate court decision allows it to continue to offer the product for sale to U.S. customers.
The steel at issue is desirable within the automotive segment because the thinner, lighter weight, high-strength grades help vehicles meet safety requirements while improving fuel efficiency. The steel is used for the hot-stamping process, which modified the steel's crystalline structure to produce stronger grades, involves rapidly heating the steel, stamping it into parts of a desired shape and then rapidly cooling it.