材料期刊网

以铸坯表层原奥氏体晶粒尺寸理论计算为基础，建立了连铸坯表层奥氏体晶粒尺寸计算模型，用面向对象的Visual Basic 6.0高级语言,开发了相应的计算机计算软件。该软件具有较好的准确性、实用性、通用性和易操作性，其仿真结果能较好地指导现场工作和实验室研究。通过仿真计算可以得出钢中碳质量分数为0.15%~0.18%时铸坯表层奥氏体晶粒尺寸较大，特别是碳质量分数0.17%时，原奥氏体晶粒尺寸最大。还可以得到结晶器冷却速度与表层原奥氏体晶粒尺寸的定量关系，随冷却速度的增大，铸坯表层原奥氏体晶粒尺寸呈指数的衰减关系。

A mathematical model of calculating original austenite grain size on the surface of the billet based on the calculation theory of the surface slab has been developed. The model can be solved by the object oriented computer language Visual Basic 6.0 and the corresponding computer simulation software has been programmed. The software has more accuracy, practicality, versatility and ease of operation. The simulation results can better guide the field work and laboratory research. The simulation results show that the austenite grain size is larger with carbon content of 0.15%-0.18%, especially the 0.17%C, the original austenite grain size is the largest. The quantitative relationship between the cooling rate of the mold and original austenite grain size has been obtained. Original austenite grain size of the slab surface presents exponential decay relationship with the increase of cooling rate.