Microstructure and mechanical properties of multilayered steel

Microstructure and corresponding mechanical properties of multilayered steel were revealed by SEM observation and analysis of tensile and bending properties. Analysis results show that the tensile strength of multilayered steel is 966 MPa, the elongation is 17% and this material exhibits excellent bending properties, the bending strength is 5 452 MPa, bending deflection is 22 mm when the multilayered steel is bent to 136°. From the tensile fracture and the microscopic appearance of bending to 180°, it can be found that brittle cracking appeared in big block phase of middle layer and dimple fracture characteristics appeared at matrix during the fracture process, delamination cracking were easily induced in the interface between Ni layer and the middle layer; However, there were satisfied interface between the martensitic layer of on both sides and the Ni layer, and a lot of plastic deformation with dimple morphology were produced in the interface between the martensitic layer of on both sides and the Ni layer with during the tension and produced in bending.