Enhancing ductility of Q235/SUS304 multilayered steels via laminate-network coupling structure

Q235/SUS304 multilayered steel with laminate-network (LN) structure was successfully fabricated by warm rolling, achieving 67% increase in tensile ductility compared to the laminate-flat (LF) structure. In LF structure, shear banding deformation induces periodic necking or fracture in SUS304 layer during tensile testing. However, under the constraint of remarkably strengthened interfaces, the LN structure multilayered steel exhibits distinct multi-stage deformation behavior in the fracture zone, where the network structure progressively flattens, followed by the reoccurrence of periodic necking. This is because the LN structure can more effectively achieve strain and stress partitioning between the soft and hard phases.