Abstract: The use of precipitation strengthening method can increase the strength of steel while less damaging plasticity and toughness. This streng-thening method has become one of the research focuses in this field because of its characteristics of effectively improving the strength and toughness of steel, and has been widely used in the production of high-performance steel. The common strengthening precipitates in steel are microalloy carbonitrides, which can be divided into interstitial phases or interstitial compounds according to the ratio of the atomic radius of the microalloying elements Nb, V, and Ti to the atomic radius of C and N. The quantitative analysis of the precipitation about these two precipitates in austenite or ferrite is generally carried out by the law of solid solubility. The solid solubility product formula is derived from thermodynamics, but the actual precipitation process is in a non-equilibrium state. The precipitation of microalloy carbonitrides during hot rolling will affect the dynamic recrystallization of austenite, while the precipitation in ferrite during cooling has a strengthening effect. NrT curve and PTT curve are important parameters for measuring precipitation. They are formulated under certain alloy element content, precipitation temperature and hot rolling process para-meters. The precipitation kinetics is described by the NrT curve and the PTT curve, which are formulated under a certain alloy element content, precipitation temperature and hot rolling process parameters, and are important parameters for measuring precipitation. The average size of precipitated particles is the smallest at the nose tip temperature of the NrT curve, and the precipitation time is the shortest at the nose tip temperature of the PTT curve. The precipitation of particles in austenite can increase the complete recrystallization temperature, which is conducive to rolling in the non-recrystallization temperature range, thereby promoting grain refinement. The strengthening effects of precipitation in ferrite include interphase precipitation strengthening and dispersion precipitation strengthening. At present, the research on the strengthening effect of precipitates is mainly focused on controlling the volume fraction, size and shape of steel. At present, certain results have been achieved in related researches on the purpose of improving the strength and toughness of steel by controlling the volume fraction, size and shape of the precipitated phases in the steel. Future research focuses on the precipitation behavior under non-equilibrium conditions, the lattice mismatch between the precipitated phase and the matrix, the chemical increase of the precipitated phase, and the strengthening of the modulus caused by the deformation of the precipitated phase. Future researches should focus on the precipitation behavior under non-equilibrium conditions, the lattice mismatch between the precipitated phase and the matrix, the chemical increase of the precipitated phase, and the strengthening effect of the modulus strengthening caused by the precipitated phase deformation on the steel.
李钊, 吴润. 钢中强化析出相的理论基础及其应用研究进展[J]. 材料导报, 2020, 34(Z2): 412-417.
LI Zhao, WU Run. Research Development of Theoretical Basis and Application of Strengthening Precipitates in Steel. Materials Reports, 2020, 34(Z2): 412-417.