Federal Circuit Denies Petition by ArcelorMittal France for Rehearing in Patent Infringement Case

Washington, D.C. — The United States Court of Appeals for the Federal Circuit denied the petition of ArcelorMittal for a rehearing in its patent infringement lawsuit against AK Steel involving ULTRALUME®.

AK Steel produces flat-rolled carbon and stainless and electrical steels.  Their products are primarily for automotive, infrastructure, manufacturing, construction, and electricity-generation and distribution markets. The company, headquartered in West Chester, Ohio, also employs people in Indiana, Pennsylvania, and Kentucky.

ArcelorMittal is a multinational steel manufacturing corporation headquartered in Avenue de la Liberté, Luxembourg. It is the world’s largest steel producer, with an annual crude steel production of 97.2 million tons as of 2011.

At issue in this suit was a claim of patent infringement by ArcelorMittal France and ArcelorMittal Atlantique et Lorraine (collectively “ArcelorMittal”) against AK Steel et al. of Patent No. 6,296,805, entitled “Coated hot- and cold-rolled steel sheet comprising a very high resistance after thermal treatment,” (“the ‘805 patent”) which has been issued by the U.S. Patent Office

The ‘805 patent covers boron steel sheeting with an aluminum-based coating applied after rolling the sheet to its final thickness. The steel is used for “hot-stamping,” a process which involves rapidly heating the steel, stamping it into parts of the desired shape, and then rapidly cooling them.  The rapid heating and cooling alters the crystalline structure of the steel, converting it to austenite and then martensite.  By altering the steel’s microstructure in this manner, hot-stamping produces particularly strong steel.  Because hot-stamped steel is so strong, parts created using the process can be thinner and lighter than steel parts produced with other methods while being just as strong.

ArcelorMittal sued AK Steel and two other steel producers in the United States District Court for the District of Delaware, alleging infringement of the ‘805 patent.  In 2011, a jury found that defendants AK Steel, Severstal Dearborn, Inc., and Wheeling-Nisshin Inc. had not infringed ArcelorMittal’s patent and that the asserted claims were invalid as anticipated and obvious.

ArcelorMittal appealed from the judgment of the trial court, challenging both the district court’s claim construction and the jury’s verdict.

The federal circuit upheld the district court’s claim construction in part and reversed it in part. It also reversed the jury’s verdict of anticipation.  With respect to obviousness, a new trial was required because a claim-construction error by the district court prevented the jury from properly considering ArcelorMittal’s evidence of commercial success.

Despite the mixed results – partially affirming, partially reversing, partially vacating and remanding for a new trial – the decision of the federal circuit has confirmed that AK Steel did not infringe Arcelor’s patent and can sell Ultralume, its aluminized boron steel product.

Practice Tip: Patent decisions of the Federal Circuit, a federal appellate court, are unique in that they are binding precedent throughout the United States.  Decisions of the Federal Circuit can be superseded only by decisions of the U.S. Supreme Court or by legislation.  As such, Federal Circuit decisions are often the final word nationwide on the issues of patent law that the court decides.  In contrast, the authority of other federal appellate courts is restricted by geographic location.  In those courts, the federal common law often varies among the circuits (a “circuit split”). 

This case was before The Honorable Timothy B. Dyk, Circuit Judge, Raymond C. Clevenger, III, Circuit Judge and Evan J. Wallach, Circuit Judge United States Court of Appeals for the Federal Circuit, and assigned Case No. 2011 1638.

CAFC Opinion -ArcelorMittal v AK Steel

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