连续铸造稳态温度场非物理边界条件的确定

建立了描述连续铸造过程的温度场模型,用外推法得出凝固金属在结晶器出口侧的非物理边界条件模型,使稳态温度场的计算精确高效.利用该温度场模型及非物理边界条件模型计算了Al-Cu合金在半连续铸造过程中的稳态温度场,并以此确定的介观温度场作为液固相变模拟的条件,用多尺度计算技术模拟了Al-10%Cu合金在不同浇注温度时的凝固组织,得到了晶粒形貌和分布合理的微观组织.对ZL201合金的近液相线铸造组织的模拟结果与实验吻合.研究表明:该温度场模型及非物理边界条件模型适于稳态连续铸造过程的模拟,并可为金属凝固组织的多尺度模拟提供正确的温度场数据.

Non-physical Boundary Condition of Steady Temperature Field in Continuous Casting Process

A model of temperature field was developed to describe the continuous casting process.The model of the non-physical boundary condition of temperature field was also proposed by extrapolation technique for the castings out of the mould to get efficient and accurate calculation results of the steady temperature fields.Then,the steady temperature fields of Al-Cu alloys in semi-continuous casting process were calculated using the given models,and the mesoscale temperature field thus determined was taken as the conditions for the simulation of liquid-solid phase transformation.The calculated temperature fields were applied to the multi-scale simulation of the solidification of the Al-10%Cu alloys at different pouring temperatures,thus obtaining the morphology and reasonably distributed grain structure.It was found that the simulated grain size and morphology of near liquidus cast ZL201 alloy is well consistent with experimental results.All the results show that the models developed for temperature field and non-physical boundary condition are applicable to the simulation of steady continuous casting process,especially they can provide correct data of temperature fields as reference for the multi-scale simulation of solidified metal structure.