Editing Stainless steel (section)

=== Corrosion resistance ===

Although stainless steel does rust, this only affects the outer few layers of atoms, its chromium content shielding deeper layers from oxidation.

The addition of nitrogen also improves resistance to pitting corrosion and increases mechanical strength.<ref name="ISSFstaff_SSFamilyPDF_20200308">{{cite web |author=International Stainless Steel Forum |date=8 March 2020 |title=The Stainless Steel Family |url=http://www.worldstainless.org/Files/issf/non-image-files/PDF/TheStainlessSteelFamily.pdf |url-status=live |archive-url=https://web.archive.org/web/20160324085201/http://www.worldstainless.org/Files/ISSF/non-image-files/PDF/TheStainlessSteelFamily.pdf |archive-date=24 March 2016 |access-date=8 March 2020 |location=Brussels, Belgium}}</ref> Thus, there are numerous grades of stainless steel with varying chromium and molybdenum contents to suit the environment the alloy must endure.<ref>{{cite web |author=International Stainless Steel Forum |date=21 September 2018 |title=Corrosion Resistance of Stainless Steels |url=https://www.imoa.info/download_files/stainless-steel/issf/educational/Module_05_Corrosion_Resistance_of_Stainless_Steels_en.pdf |url-status=live |archive-url=https://web.archive.org/web/20210701021619/https://www.imoa.info/download_files/stainless-steel/issf/educational/Module_05_Corrosion_Resistance_of_Stainless_Steels_en.pdf |archive-date=1 July 2021 |access-date=16 June 2021}}</ref> Corrosion resistance can be increased further by the following means:
* increasing chromium content to more than 11%<ref name="ISSFstaff_SSFamilyPDF_20200308" />
* adding nickel to at least 8%<ref name="ISSFstaff_SSFamilyPDF_20200308" /> 
* adding molybdenum (which also improves resistance to [[pitting corrosion]])<ref name="ISSFstaff_SSFamilyPDF_20200308" />