Complementary layer thickness effects of Q235 and SUS304 layers of multilayered steels for improving of tensile strength and plasticity simultaneously

Abstract

Complementary layer thickness effects on strength and plasticity in Q235 and SUS304 steels provide a novel strategy to realize high strength and high plasticity of heterogeneous Q235/SUS304 multilayered steel. In this work, the tensile deformation behaviors and fracture characteristics of vacuum hot-rolled Q235/SUS304 multilayered steel with various layer thicknesses ranging from 223 μm to 5 μm were deeply investigated. The tensile strength improved with the reduction of layer thickness, and the uniform elongation was first increased and then decreased with decreasing layer thickness, and the peak value appeared at the layer thickness of 20 μm. Interestingly, the fracture elongation forms a high plateau value within the 10∼20 μm range. Further analysis reveals that the severe strain localization in the brittle SUS304 thin layers is delayed by the ductile Q235 layers, which is mainly attributed to the different texture evolution and dislocation configuration characteristics during tensile deformation.