Editing Heating element (section)

==== Ni-Cr(Fe) alloys (AKA nichrome, Chromel) ====
Ni-Cr(Fe) resistance heating alloys, also known as [[nichrome]] or [[Chromel]], are described by both ASTM and DIN standards.<ref name=":3">{{Cite report |url=http://www.astm.org/cgi-bin/resolver.cgi?B344-20 |title=Specification for Drawn or Rolled Nickel-Chromium and Nickel-Chromium-Iron Alloys for Electrical Heating Elements |last=B02 Committee |publisher=ASTM International |doi=10.1520/b0344-20 |language=en|url-access=subscription }}</ref><ref name=":5">{{Cite report |url=https://www.beuth.de/de/-/-/1151382 |title=DIN 17470:1984-10, Heizleiterlegierungen; Technische Lieferbedingungen für Rund- und Flachdrähte |publisher=Beuth Verlag GmbH |doi=10.31030/1164343|url-access=subscription }}</ref> These standards specify the relative percentages of [[nickel]] and [[chromium]] that should be present in an alloy. In ASTM three alloys that are specified contain, amongst other trace elements:

* 80% Ni, 20% Cr
* 60% Ni, 16% Cr
* 35% Ni, 20% Cr

Nichrome 80/20 is one of the most commonly used resistance heating alloys because it has relatively high resistance and forms an adherent layer of [[chromium oxide]] when it is heated for the first time. Material beneath this layer will not oxidize, preventing the wire from breaking or burning out.