中文摘要：

钢中第二相的合理控制对于提高钢铁材料的综合性能具有重要意义，而第二相控制的关键在于准确掌握第二相在铁基体中的固溶与析出行为。多元第二相平衡固溶的定量计算是第二相固溶与析出行为研究中的一个难点问题。以铌、钒、钛的微合金碳氮化物为例讨论了钢中三元第二相平衡固溶的热力学模型与计算方法及其在含钛渗碳齿轮钢产品开发中的应用。由于该方法求解计算量较大，在其基础上开发了一套可以自动计算和对比分析其中各个控制参量的通用分析计算软件，该软件可以有效应用于微合金钢的成分设计、生产工艺控制和钢种开发等，具有重要的工程应用价值。

英文摘要：

The rational control of second-phase is significant to improve the comprehensive performance of steel material,and the key point in second-phase controlling is to accurately understand its solid solution and precipitation behavior in iron matrix.The quantitative computation of balanced solid solubility of multiplex second-phase is one of difficult problems in this area.The thermodynamic model and computing method of solid solution precipitation of ternary second-phase in steel were discussed,taking the Nb-V-Ti microalloying carbonitride as an example,and its engineering application in the development of Ti-bearing carbonized gear steel product was introduced.Due to the complexity of the theoretical model,a general-purpose calculation software was developed,which could automatically compute and analyze the controlling parameters in the model.This software is effectively applicable to the composition design,producing process control and new type development of microalloying steel,and has important practical application value.