Editing Stainless steel (section)

=== High-temperature ===

At elevated temperatures, all metals react with hot gases. The most common high-temperature gaseous mixture is air, of which oxygen is the most reactive component. To avoid corrosion in air, carbon steel is limited to approximately {{convert|480|C|F|sigfig=2|abbr=}}. Oxidation resistance in stainless steels increases with additions of chromium, silicon, and aluminium. Small additions of [[cerium]] and [[yttrium]] increase the adhesion of the oxide layer on the surface.<ref>{{Cite web |url=https://www.bssa.org.uk/topics.php?article=107 |title=Oxidation resistance of stainless steels |publisher=British Stainless Steel Association |access-date=1 October 2021 |archive-date=7 August 2020 |archive-url=https://web.archive.org/web/20200807084144/https://www.bssa.org.uk/topics.php?article=107 |url-status=live }}</ref> The addition of chromium remains the most common method to increase high-temperature corrosion resistance in stainless steels; chromium reacts with oxygen to form a chromium oxide scale, which reduces oxygen diffusion into the material. The minimum 10.5% chromium in stainless steels provides resistance to approximately {{convert|700|C|F|sigfig=2|abbr=}}, while 16% chromium provides resistance up to approximately {{convert|1200|C|F|sigfig=2|abbr=}}. Type 304, the most common grade of stainless steel with 18% chromium, is resistant to approximately {{convert|870|C|F|sigfig=2|abbr=}}. Other gases, such as [[sulfur dioxide]], [[hydrogen sulfide]], [[carbon monoxide]], [[chlorine]], also attack stainless steel. Resistance to other gases is dependent on the type of gas, the temperature, and the alloying content of the stainless steel.<ref>{{Cite web |last=American Iron and Steel Institute |date=April 1979 |title=High Temperature Characteristics of Stainless Steel |url=https://nickelinstitute.org/en/library/technical-guides/high-temperature-characteristics-of-stainless-steel-9004/ |url-status=live |archive-url=https://web.archive.org/web/20180307082335/https://nickelinstitute.org/~/media/Files/TechnicalLiterature/High_TemperatureCharacteristicsofStainlessSteel_9004_.ashx |archive-date=7 March 2018 |access-date=1 October 2021 |website=Nickel Institute}}</ref><ref>{{Cite web |last=Elliott |first=Peter |date=August 1990 |title=Practical Guide to High Temperature Alloys |url=https://nickelinstitute.org/en/library/technical-guides/practical-guide-to-high-temperature-alloys-10056/ |url-status=live |archive-url=https://web.archive.org/web/20180307150834/https://nickelinstitute.org/~/media/Files/TechnicalLiterature/PracticalGuidetoHigh_TemperatureAlloys_10056_.ashx |archive-date=7 March 2018 |access-date=1 October 2021 |website=Nickel Institute}}</ref> With the addition of up to 5% aluminium, ferritic grades Fe-Cr-Al are designed for electrical resistance and oxidation resistance at elevated temperatures. Such alloys include [[Kanthal (alloy)|Kanthal]], produced in the form of wire or ribbons.<ref name="ISSF-2017">{{Cite book|url=http://worldstainless.org/publications/brochures_and_posters|title=The ferritic solution Properties/advantages/applications|date=April 2017|publisher=ISSF, International Stainless Steel Forum |isbn=978-2-930069-51-7|access-date=15 October 2018|archive-url=https://web.archive.org/web/20181012045555/http://www.worldstainless.org/publications/brochures_and_posters|archive-date=12 October 2018|url-status=dead}}</ref>