Fracture elongation of brittle/ductile multilayered steel composites with a strong interface

The ductile tensile deformation behavior of multilayered steel composites consisting of brittle martensitic steel and ductile steel layers, which were prepared by hot rolling to achieve a strong interface, was investigated. A clear enhancement of the fracture elongation with decreased layer thickness was seen, while the tensile strength ratio between the constituent materials as well as the hardening exponent was found to be crucial for optimizing the ductility. A good strength–ductility balance, 1.2 GPa tensile strength and 15% uniform elongation, was achieved solely using conventional steels.