The structure and properties of κ-carbides in duplex lightweight steels

κ-carbide in lightweight steel is studied. Its thermal stability, crystal morphology, orientation relationship, degree of lattice misfit and mechanical properties are measured experimentally. The mechanisms for the microstructural evolution of κ-carbide are considered based on the crystal structure, lattice misfit, element diffusivity, and solute partition. The hard γ/κ grain and ductile α+κ grain provide an opportunity to develop the lightweight steels with desirable combination of mechanical properties.