普适的碳氮化物析出热力学模型的建立

基于规则溶体模型、双亚点阵模型及第二相固溶析出理论,建立了普适的碳氮化物析出热力学模型.采用该模型,计算了不同温度下0.17C-0.023Nb-0.012Ti-0.004N钢中理想配比型及缺位型析出相与基体间的热力学平衡信息,包括基体成分、析出相成分及其体积分数.结果表明:在相同温度下,相比于理想型第二相,缺位型第二相的溶解度较大,析出体积分数较小;随着析出温度的降低,析出相逐渐由氮化钛演变为富含铌和碳的复合相,且不同类型第二相的体积分数差异逐渐缩小.

Development of Universal Thermodynamic Model for Carbo-Nitride Precipitation

Based on the regular solution approximation， the two sub-lattice model and dissolution and precipitation theory， a universal thermodynamic model for carbo-nitride precipitation was established. The model was used to calculate the thermodynamic equilibrium information including matrix composition， composition and volume fraction of precipitation between sub-stoichiometric or stoichiometric precipitation and matrix of the 0.17C-0.023Nb-0.012Ti-0.004N at different temperatures. The results showed that the solubility of sub-stoichiometric precipitation is bigger than that of stoichiometric precipitation， and the volume fraction of the former is less than the latter one at the same temperature. With the decrease of the temperature， the precipitation is gradually changing from titanium nitride to complex precipitation which is rich in niobium and carbon， and the volume fraction differences in different precipitations also decrease gradually.