Editing Cast iron (section)

===Malleable cast iron===
{{Main|Malleable iron}}
Malleable iron starts as a white iron casting that is then [[heat treatment|heat treated]] for a day or two at about {{Convert|950|C|abbr=on}} and then cooled over a day or two. As a result, the carbon in iron carbide transforms into graphite and ferrite plus carbon. The slow process allows the [[surface tension]] to form the graphite into spheroidal particles rather than flakes. Due to their lower [[aspect ratio]], the spheroids are relatively short and far from one another, and have a lower [[cross section (geometry)|cross section]] vis-a-vis a propagating crack or [[phonon]]. They also have blunt boundaries, as opposed to flakes, which alleviates the stress concentration problems found in grey cast iron. In general, the properties of malleable cast iron are more like those of [[mild steel]]. There is a limit to how large a part can be cast in malleable iron, as it is made from white cast iron.{{Citation needed|date=March 2021}}