ABSTRACT
Chromium is a metal that readily forms an oxide that is transparent and
happens to be extremely resistant to further degradation. As a further benefit
to alloying with steel, it is less noble than iron and thus tends to form its
oxide first. Increasing the chromium content in steel gradually above about
2% improves mild atmospheric corrosion resistance steadily up to a level of
about 12% where corrosion is essentially arrested. For exposure to mild, wet
environments the addition of about 11% chromium is sufficient to prevent
“rusting” of steel components, hence the term stainless.
