Cryogenic tensile fracture behavior of equal-channel angular pressed high-Mn steel

Abstract

In this work, the mechanical properties of equal-channel angular pressed high-Mn steel were investigated at cryogenic temperatures. Microstructural assessment demonstrated that the imposed large shear strains after 1 pass and 12 passes ECAP resulted in both grain refinement and formation of nanotwins in the material comprising a heterogeneous hierarchical fine structure. This microstructure contributes to a significant strength enhancement in a cryogenic environment. We show that ultrafine-grained high-Mn steels can have a great po-tential for sustaining in cryogenic environments owing to their high strength. Also, the effects of heterogeneity induced by heavy straining of the initially coarse-grained material are discussed.