NEW YORK ArcelorMittal SA has filed two more lawsuits against AK Steel Corp., Severstal Dearborn Inc. and Wheeling-Nisshin Inc. for allegedly infringing on its patent for aluminized boron steel sheet products, continuing a legal battle that is now more than three years old.
ArcelorMittal alleges that West Chester, Ohio-based AK Steel, Dearborn, Mich.-based Severstal and Follansbee, W.Va.-based Wheeling-Nisshin produce steel that is processed by companies that infringe on an aluminum-coated-steel patent held by ArcelorMittal France and ArcelorMittal Atlantique et Lorraine.
"Companies that process steel manufactured by (the defendants)for example, by heat-treating and stampingdirectly infringe one or more of the claims of the (patent)," according to documents filed April 16 in U.S. District Court in Delaware. "ArcelorMittal has been damaged by such infringement and will continue to be damaged by such infringement unless (the defendants) are enjoined from infringing by this court."
ArcelorMittals patent covers both hot-rolled and cold-rolled sheet steel but is limited to steel with a tensile strength above 1,500 megapascals (MPa), according to an appellate court ruling earlier this year (amm.com, March 27). AK Steels Ultralume product, for example, which has a tensile strength of up to 1,500 MPa, was not found to be in violation of ArcelorMittals patent.
However, the defendants are aware that at least some of their product, "upon further processing, achieves an ultimate tensile strength of greater than 1,500 MPa," Luxembourg-based ArcelorMittal said in its lawsuits.
Representatives for AK Steel and Severstal said they were confident they would win the case and be able to continue selling their aluminum-coated steel sheet products.
"The recent lawsuits filed by ArcelorMittal against AK Steel and Severstal represent a continued attempt by ArcelorMittal to overcome the fact that it lost on the infringement issue in its original lawsuit," an AK Steel spokesman said. "We do not believe that ArcelorMittal will be any more successful in this latest attempt and we intend to continue to vigorously contest its claims."
Wheeling-Nisshin did not respond to calls for comment.
An ArcelorMittal spokesperson said the company remains committed to protecting its intellectual property portfolio.