Corrosion and Auger Studies of a Nickel‐Base Metal‐Metalloid Glass: I . The Effect of Elemental Interactions on Passivity in the General Corrosion of Metglass 2826A

Abstract

The general corrosion behavior of , Metglass 2826A, was assessed as a function of heat‐treatment and surface finish by cyclic potentiodynamic anodic polarization. The general corrosion resistance of Metglass 2826A decreased in this order: supersaturated solid solution (SS) anneal, polished, as‐received, subcritical anneal ( then ) and a high temperature primary crystallization (MP) anneal. Ranking of the general corrosion resistance was correlated with the partitioning of elemental species as determined by AES analysis and through the definition of interaction parameters. Good passivity is achieved by a strong positive (+) Cr‐B association and by interactions, (+) Ni‐P, (−) P‐B, which promote the formation of a Cr‐B complex. Passivity is degraded by metal‐metal and metal‐metalloid mixing as reflected in the establishment of positive interactions for Fe‐Cr, Ni‐Cr, and Ni‐B.