Ultra-strong cold-drawn 2507 stainless steel wire with heterogenous microstructure of dual-phase and grain size

Obtaining ultrafine grains through severe plastic deformation is a highly effective strategy for improving the strength of metallic materials. Due to the different deformation mechanisms between ferrite and austenite, the heavily drawn 2507 stainless steel wire possesses a significant heterogeneous structure at drawing strain ε = 6.65. In this study, a 2507 duplex stainless steel (DSS) with a strength of 2.7 GPa was prepared by cold drawing process. The deformation production of the ferrite in the wire is simply dislocation, which subsequently transforms to subgrain boundary and high angle grains boundary. While the production of the austenite is dislocation and twinning. In addition, based on the boundary strengthening, solid solution hardening and lattice friction, the contribution of the deformed ferrite and deformed austenite to the yield stress is 2260 MPa and 2800 MPa, respectively.