Abstract
High purity iron, cast and rolled more than 20 years ago and stored without special precautions in the laboratory, has largely maintained its bright surface finish over this period of time, showing that iron is stably passivated by air. Since long‐term (>1 yr) oxidation studies of iron do not exist and since iron is usually thought to rust in air at moderate relative humidities, the thickness of the passivating oxide film was measured by Auger electron spectroscopy and depth profiling. After corrections for an adsorbed carbonaceous layer, the thickness was estimated to be 5–6 nm. This is in reasonable agreement with extrapolations of short‐term (<24h) oxide film thickness data from gaseous and anodic oxidation studies in the literature.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
