(May 17, 2017, 3:42 PM EDT) -- WASHINGTON, D.C. — In a divided May 16 ruling, the Federal Circuit U.S. Court of Appeals found no error in a Delaware federal judge’s decision to invalidate two claims of a reissue patent directed to a boron-containing steel sheet (ArcelorMittal, et al. v. AK Steel Corp., et al., No. 16-1357, Fed. Cir., 2017 U.S. App. LEXIS 8565)....