Heterostructure alleviates L?ders deformation of ultrafine-grained stainless steels

Ultrafine-grained (UFG) 304 stainless steel is much stronger than its coarse-grained counterpart. However, it develops undesired Luders bands during deformation. Here we report a bi-modal heterostructure that can effectively suppress Luders deformation in the UFG 304 stainless steel, which produces a strong strain hardening to improve the ductility and toughness, without sacrificing much strength. These superior mechanical properties are attributed to strain delocalization capability of the bi-modal heterostructure, which results in lower stress concentration and consequently postpones the martensitic transformation.

Automated summary

By introducing a bi-modal heterostructure, Luders deformation in UFG 304 stainless steel can be effectively suppressed, leading to improved ductility and toughness without sacrificing strength.