孟庆勇,王福明,李长荣,李梦龙,庞瑞朋

• 1:北京科技大学冶金与生态工程学院
• 2:北京科技大学材料科学与工程学院

摘要(Abstract)：

基于体积平均的两相数学模型,耦合求解温度场、流场和浓度场,模拟计算过热度对12Cr2Mo1R大扁锭凝固过程碳元素宏观偏析的影响。本模型将钢液密度设为依赖于温度和溶质浓度的函数。因而,可以综合考虑温度梯度、浓度梯度以及体积收缩等因素对钢液流动的作用,能够更加精确地预测凝固过程溶质元素分布。本次实验研究了过热度对凝固前沿温度梯度、凝固速率和钢液流动速率影响规律,以及最终碳元素宏观偏析情况。模拟结果表明:过热度的增加导致铸件表面区域凝固前沿温度梯度升高,而对中心线区域凝固前沿温度梯度的影响不显著;过热度对铸锭凝固速率的影响很小。此外,过热度的增加使得钢液流动速度相应增加,并使得固液两相区宽度相应的减小。铸锭凝固过程中碳元素宏观中心偏析总体表现为:当过热度<40℃时,增加过热度对加剧铸锭中心偏析不显著;然而,当过热度>40℃时,提高过热度使得铸锭中心偏析急剧恶化。

关键词(KeyWords)： 过热度;中心偏析;数值模拟;大扁锭

Abstract:

Keywords:

基金项目(Foundation): 国家自然科学基金(51374018,51174020);; 国家高技术研究发展计划项目(2013AA031601);; 中央高校基本科研业务费专项资金(FRF-SD-12-010A)

作者(Author): 孟庆勇,王福明,李长荣,李梦龙,庞瑞朋

DOI: 10.13289/j.issn.1009-6264.2015.03.044

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