Current developments of nanoscale insight into corrosion protection by passive oxide films

TL;DR

This paper reviews recent nanoscale experimental and theoretical advances in understanding passive oxide films, crucial for metal corrosion protection, focusing on composition, grain boundary behavior, and organic inhibitor interactions.

Contribution

It provides a comprehensive overview of recent nanoscale insights into passive oxide films, highlighting key issues and future research directions in corrosion science.

Findings

Chromium enrichment and homogeneity at nanoscale in passive films

Corrosion behavior of grain boundaries in early intergranular corrosion

Interaction of organic inhibitors with incompletely passivated surfaces

Abstract

Oxide passive films are a key for the durability of metals and alloys components as well as a central issue in corrosion science and engineering. Herein, we discuss current developments of the nanometer and sub-nanometer scale knowledge of the barrier properties and adsorption properties of passive oxide films brought by recent model experimental and theoretical investigations. The discussed aspects include (i) the chromium enrichment and its homogeneity at the nanoscale in passive films formed on Cr-bearing alloys such as stainless steel, (ii) the corrosion properties of grain boundaries in early intergranular corrosion before penetration and propagation in the grain boundary network, and (iii) the interaction of organic inhibitor molecules with incompletely passivated metallic surfaces. In all three cases, key issues are highlighted and future developments that we consider as most relevant are identified.