重压下含铌钛连铸坯碳氮化物析出行为的研究

钢中合金元素的添加会不同程度的形成碳、氮化物进而提高钢材的组织与性能，为研究重压下铸坯析出物的析出行为，本文以规则溶液下亚点阵模型为基础，计算热力学平衡状态下热力学参数。通过热力平衡方程组，得出一定温度下，析出物摩尔分数、亚点阵中不同元素原子分配比，利用能谱分析及透射电镜观察验证这种析出模式。计算结果表明，不同压下制度铸坯中析出物主要为(Nb，Ti)(C，N)析出，尺寸在30～40 nm左右。

Study on evolution of precipitates in Nb Ti carbonitride at the slab heavy reduction

Adding alloying elements in steel forms some carbide and nitride， and the microstructure and properties of steel are improved. For the study of evolution of precipitates at the heavy reduction slab， this paper based on Sub-Lattice Model in regular solution to calculate the thermodynamic parameters at the thermodynamic equilibrium condition. Through the thermodynamic equilibrium equations， precipitates mole fraction， distribution ratio of the various elements in Sub-Lattice at a certain temperature were concluded. This precipitation pattern was verified using the energy spectrum analysis and transmission electron microscope. The calculation results show that precipitates under different heavy reduction casting are mainly (Nb， Ti) (C， N) precipitation， and the size is about 30-40 nm.