Long-term corrosion resistance of iron-based amorphous metal coatings

Novel iron-based amorphous metals, including SAM2X5 Fe(49.7)Cr(17.7)Mn(1.9)Mo(7.4)W(1.6)B(15.2)C(3.8)Si(2.4)), SAM1651 (Fe(48.0)Cr(15.0)Mo(14.0)B(6.0)C(15.0)Y(2.0)), and other compositions have been developed for use as corrosion-resistant coatings for spent nuclear fuel containers, as criticality control materials, and as ultra-hard corrosion-resistant material for ship applications. These amorphous alloys appear to have corrosion resistance comparable to (or better than) that of Ni-based Alloy C-22 (UNS # N06022), based on measurements of breakdown potential and corrosion rate in seawater. A variety of characterization tools, including scanning electron microscopy, cyclic polarization, linear polarization and electrochemical impedance spectroscopy, have been used to develop a thorough understanding of the corrosion performance of these alloys over prolonged exposure in seawater and concentrated brines at elevated temperature. U.S. Department of Energy, National Nuclear Security Administration Contract DE-AC52-07NA27344