engleski

Electrochemical Passivation of a Biomedical-grade 316LVM Stainless Steel

The present work aimed at developing a simple electrochemical passivation method for a biomedical-grade stainless steel 316LVM in order to increase its pitting corrosion resistance. The results showed that the passivation of 316LVM by employing a cyclic potentiodynamic polarization method can provide a significant improvement in pitting corrosion resistance of the material. A complete absence of pitting in physiological solutions was achieved. Even at significantly higher concentrations of chlorides, relevant to marine and industrial applications, an improvement in pitting potential by ca. 870 mV was observed. An increase in temperature during the passivation process did not have a significant effect on the resulting passive film pitting corrosion resistance, while an increase in temperature of the testing solution resulted in a significant decrease in the pitting corrosion resistance of the material investigated. The results suggest that both a change in dielectric properties of the passive film and its enrichment in chromium are responsible for the observed improvement in corrosion resistance. A mechanism of the passive film pitting breakdown was proposed.

Stainless steel 316LVM; Passivation; Corrosion resistance; Semiconducting properties

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