NEW YORK A judgment in a patent lawsuit filed by ArcelorMittal SAs French units against AK Steel Corp., Severstal Dearborn Inc. and Wheeling-Nisshin Inc. has been sent back to U.S. District Court in Delaware for further review.
The U.S. Court of Appeals said a jury verdict that a U.S. patent for boron steel sheet with an aluminum-based coating held by ArcelorMittal France and ArcelorMittal Atlantique et Lorraine had not been infringed upon by the other steelmakers was based on an incorrect definition of the product.
Fridays remand ruling said the Delaware court misinterpreted the definition of boron steel sheet and decided incorrectly that the definition applied to steel sheet that was hot-rolled but not cold-rolled. Furthermore, ArcelorMittal did not fully disclose all the specifications of the boron sheet, which were used to determine the commercial success of the steelmakers boron sheet products. Thus, when a jury decided that ArcelorMittals patent was not infringed, the decision did not properly consider the patent or the product in dispute, the appeals court said, and sent those items back to the district court for review.
"This decision definitely confirms ArcelorMittals position that the Usibor patent also applies to cold-rolled steel for hot stamping and was not limited to hot-rolled steel, as falsely alleged by the defendants," an ArcelorMittal USA Inc. spokeswoman told AMM in an e-mail. "ArcelorMittal is pleased with the decision confirming its patent rights ... and will continue to defend its patent rights against any potential infringement moving forward."
West Chester, Ohio-based AK Steel said the decision affirmed the initial judgment of "no infringement" and only questioned findings as to the patents validity. "Regardless of the outcome of the new trial on the validity of the patent, the Court of Appeals decision will allow the company to continue to offer the product for sale to customers in the United States."
The federal court in Delaware previously denied ArcelorMittals appeal of the verdict (amm.com, Aug. 29, 2011), and ArcelorMittal later appealed to the higher court.
ArcelorMittal did not respond immediately to requests for comment. Wheeling-Nisshin declined to comment.
Severstal is reviewing the courts decision and its options, a spokeswoman for the Dearborn, Mich.-based steelmaker told AMM in an e-mail.