灰铸铁凝固数值模拟的形核率模型建立  

Nucleation Model for Numerical Simulation of Solidification of Gray Iron

作　　者：张宁[1] 郑洪亮 陈凯[1] 田学雷[1] 

机构地区：[1]山东大学材料液固结构演变与加工教育部重点实验室,山东济南250061

出　　处：《铸造》2010年第2期165-168,共4页Foundry

摘　　要：设计并浇注了一系列阶梯形灰铸铁件,采用金相显微镜研究了各铸件不同位置的共晶团数量,分析了影响灰铸铁共晶形核的主要因素,探求了灰铸铁的共晶形核规律。研究表明,过冷度和碳当量对灰铸铁共晶形核起主要作用。随着过冷度的增大,灰铸铁共晶形核率增大。随着碳当量接近共晶成分,灰铸铁共晶形核率也增大。在总结灰铸铁形核理论并结合试验所得数据的基础上,采用统计学方法分别得出有关亚共晶灰铸铁和过共晶灰铸铁的形核率公式,为凝固过程数值模拟的动力学计算提供准确模型。A series of stepped castings were designed and poured, and metallographic microscope was employed to determine the number of eutectic cells. The factors that influence nucleation and the regularity of nucleation rate were studied. It is revealed that the carbon equivalent and the degree of undercooling mainly determine the nucleation rate. The eutectic cell increases as the degree of undercooling rises. The number of eutectic cells increases as the carbon equivalent is close to the eutectic composition. On the basis of theories and experiment results, a regression model of nucleation of hypoeutectic cast iron and hypereutectic cast iron was obtained, which could be the more accurate model for dynamical analysis used in solidification simulation.

关 键 词：灰铸铁 形核率 凝固过程数值模拟 

分 类 号：TG251[金属学及工艺—铸造]