Abstract: Current research status of Q&P steel was introduced through four aspects: the production process of Q&P steel, the role of alloying elements, the thermodynamics and dynamics of C composition and the influence of process parameters, and the future research direction of Q&P steel was prospected. The microstructure of Q&P steel after quenching and partitioning process is martensite and retained austenite, the martensite provides high strength and the retained austenite produces a TRIP effect to enhance the plastic deformation ability with effect of stress and strain. The heart of the Q&P process is to get the maximum availability of stable retained austenite, which depends critically on the partitioning process of C, and the optimal quenching temperature can be predicted by thermodynamic theoretical model calculations. The addition of alloying elements can inhibit the precipitation of carbides, refine austenite grains and stabilize austenite. The process parameters have a great influence on the microstructure and mechanical properties of the Q&P steel, the quenching temperature determines the content of initial martensite and the subsequent partitioning process, and the partitioning temperature and partitioning time significantly affect the diffusion power of C atoms, so it is particularly important to select the appropriate process parameters.

Key words: Q&P steel, retained austenite, mechanical properties, microstructure