Austenitic stainless steel: This type of stainless steel contains more elements that expand the γ region and stabilize austenite, which are all γ phase at high temperature. Since the Ms point is below room temperature during cooling, it has austenite structure at room temperature. 18-8, 18-12, 25-20, 20-25Mo and other chromium-nickel stainless steels, and low-nickel stainless steels with manganese replacing part of nickel and adding nitrogen such as Cr18Mn10Ni5, Cr13Ni4Mn9, Cr17Ni4Mn9N, Cr14Ni3Mn14Ti steels all belong to this category.
Austenitic stainless steels have many of the advantages mentioned above. Although the mechanical properties are relatively low, they cannot be strengthened by heat treatment like ferritic stainless steels. However, their strength can be improved by cold working and deformation by means of work hardening. The disadvantage of this type of steel is that it is sensitive to intergranular corrosion and stress corrosion, which needs to be eliminated through appropriate alloy additives and process measures.
