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AK Steel Corp. v. Sollac

United States Court of Appeals for the Federal Circuit

September 23, 2003, Decided

03-1074, 03-1075, 03-1085, 03-1086


 [***1281]   [*1236]  LOURIE, Circuit Judge.

AK Steel Corporation appeals from the decision of the United States District Court for the Southern District of Ohio granting summary judgment that its U.S. Patent 4,800,135 was not infringed by Sollac and Ugine (collectively, "Sollac") and that certain claims of its U.S. Patent 5,066,549 are invalid.  AK Steel Corp. v. Sollac, 234 F. Supp. 2d 711 (S.D. Ohio 2002). Because the court properly construed the patent claims and correctly found no genuine issues [**2]  of material fact, we affirm.


AK Steel owns the '135 and '549 patents, which are directed to hot-dip aluminum-coated stainless steel. The '549 patent issued from an application that was a continuation of the application from which the '135 patent issued. As such, the two patents have different claims but share a common specification. That specification explains that aluminum-coated stainless steel has desirable resistance to corrosion and high-temperature oxidation. '135 patent, col. 1, ll. 14-23. Those properties make such steel useful in the manufacture of components for use in automotive exhaust systems and combustion equipment. Id. Hot-dip aluminum-coated steel is produced by passing heated steel strips through molten aluminum; however, it is challenging to get the aluminum to adhere or "wet" well onto the steel. Id. at col. 2, ll. 21-25. Wetting problems can result in crazing or flaking of the aluminum coating during subsequent bending of the strip. Id. at col. 2, ll. 26-27. The inventors of the patents in suit solved the wetting problem by maintaining the steel strip in a hydrogen atmosphere prior to entry into the aluminum coating bath. Id. at col.  [**3]  2, ll. 44-50.

The inventors also discovered that their invention did not work well unless the aluminum is substantially pure, as they stated in their patent application:

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344 F.3d 1234 *; 2003 U.S. App. LEXIS 19640 **; 68 U.S.P.Q.2D (BNA) 1280 ***

AK STEEL CORPORATION, Plaintiff-Appellant, v. SOLLAC and UGINE, Defendants-Cross Appellants.

Prior History:  [**1]  Appealed from: United States District Court for the Southern District of Ohio. Judge Susan J. Dlott.

 AK Steel Corp. v. Sollac, 234 F. Supp. 2d 711, 2002 U.S. Dist. LEXIS 20716 (S.D. Ohio, 2002)

Disposition: Affirmed.


patent, aluminum, coating, silicon, Steel, invention, metal, strip, alloy, invalidity, layer, encompass, experimentation, recited, contested, inventors, infringement, chromium, ferritic, genuine, novel, hot, anticipation, correctly, resistant, adherent, endpoint, replaced, crazing, flaking

Civil Procedure, Appeals, Standards of Review, De Novo Review, Judgments, Summary Judgment, General Overview, Summary Judgment Review, Standards of Review, Burdens of Proof, Movant Persuasion & Proof, Evidentiary Considerations, Motions for Summary Judgment, Entitlement as Matter of Law, Criminal Law & Procedure, De Novo Review, Patent Law, Jurisdiction & Review, Infringement Actions, Claim Interpretation, Fact & Law Issues, Infringing Acts, Specifications, Enablement Requirement, Defenses, Patent Invalidity, Presumption of Validity, Claims, Claim Language, Claim Evaluation, Scope of Enablement, US Patent & Trademark Office Proceedings, Description Requirement, Definiteness, Common Principles & Prior Art, Standards & Tests, Subject Matter Jurisdiction, Appeals, Proof of Enablement