2024-11-22
Stainless steel-Magnetism and Other Properties of Stainless Steel
In their basic forms stainless steels have a ferritic grainstructure, similar to carbon steel, and are magnetic. Theaddition of nickel in the 300-series stainless steels modifiesthe crystal grain structure to austenitic. The austeniticgrades are mostly non-magnetic in the unworked state dueto their nickel content. When 300-series stainless steels arecold-worked, straining of the atomic lattice structure in theareas of cold-working forms the magnetic grain structuremartensite.Generally speaking, the higher the nickel content the morestable the austenitic structure and less magnetic responsefrom cold-working. Consequently 316 stainless steel, withhigher amounts of nickel, exhibits virtually no magnetismafter cold-working in most cases. While 304, with lowernickel content, may become mildly magnetic.