Influence of chromium additions on corrosion resistance of Co 75·5 Si 13·5 B 9 Nb 3 Cu 1 metallic glass in marine environment

Abstract

This study addressed the influence of Cr concentration on the corrosion resistance of Co_73·5Si_{13 ·5}B₉Nb₃Cu₁ metallic glass in simulated marine atmospheres with 1000 ppm of chlorides. Anodic and cyclic polarisation measurements were carried out to study the susceptibility to passivation and localised corrosion. The corrosion kinetics were analysed using dc electrochemical techniques. Every test was conducted using the same material in different states: amorphous, nanocrystalline and crystalline. The study also focused on changes in the magnetic properties of the material as a result of Cr addition and exposure to an aggressive medium. These properties depend mainly on the Cr concentration and the material state (amorphous, crystalline or nanocrystalline).