Editing Stainless steel (section)

=== Magnetism ===

[[Martensitic stainless steel|Martensitic]], [[Duplex stainless steel|duplex]] and [[ferritic stainless steel]]s are [[Permeability (electromagnetism)#Values for some common materials|magnetic]], while [[austenitic stainless steel]] is usually non-magnetic.<ref>{{Cite web |date=October 2008 |title=Atlas Tech Note: qualitative sorting tests for steels |url=https://www.atlassteels.com.au/documents/TN1-qualitative%20sorting%20tests%20rev%20Oct%202008.pdf |access-date=2022-08-24 |website=Atlas Steels}}</ref> Ferritic steel owes its magnetism to its [[Cubic crystal system|body-centered cubic]] [[crystal structure]], in which iron atoms are arranged in cubes (with one iron atom at each corner) and an additional iron atom in the center. This central iron atom is responsible for ferritic steel's magnetic properties.{{Citation needed|date=September 2024}} This arrangement also limits the amount of carbon the steel can absorb to around 0.025%.<ref>{{Cite web |title=What Is The Difference Between Ferritic, Austenitic & Martensitic Stainless Steels? |url=https://www.accu.co.uk/p/112-what-is-the-difference-between-ferritic-austenitic-martensitic-stainless-steels-accu |access-date=2022-08-24 |website=Accu.co.uk}}</ref> Grades with low coercive field have been developed for electro-valves used in household appliances and for injection systems in internal combustion engines. Some applications require non-magnetic materials, such as [[magnetic resonance imaging]].{{citation needed|date=June 2021}} [[austenitic stainless steel|Austenitic]] stainless steels, which are usually [[Permeability (electromagnetism)#Values for some common materials|non-magnetic]], can be made slightly magnetic through [[work hardening]]. Sometimes, if austenitic steel is bent or cut, magnetism occurs along the edge of the stainless steel because the crystal structure rearranges itself.<ref>{{Cite web |title=Why don't magnets work on some stainless steels? |url=https://www.scientificamerican.com/article/why-dont-magnets-work-on/ |access-date=2022-07-22 |website=Scientific American |language=en}}</ref>
{| class="wikitable"
|+Magnetic permeability of some austenitic stainless steel grades after annealing 2 hours at 1050{{nbsp}}°C<ref>{{Cite news|last1=Fofanov|first1=D.|title=Magnetic properties of Stainless Steels: applications, opportunities, and new developments|date=29 Nov 2011|work=Stainless steel World Conference|last2=Riedner|first2=S.}}</ref>
|-
! EN grade
! 1.4307
! 1.4301
! 1.4404
! 1.4435
|-
| Magnetic permeability, μ
| 1.056
| 1.011
| 1.100
| 1.000
|}