电渣重熔H13模具钢过程碳偏析的模拟研究  

Simulation of carbon segregation during electroslag remelting of H13 die steel

作　　者：段怡如 李宝宽 黄雪驰 刘中秋 柴玉莹 Yiru DUAN;Baokuan LI;Xuechi HUANG;Zhongqiu LIU;Yuying CHAI(School of Metallurgy,Northeastern University,Shenyang,Liaoning 110819,China)

机构地区：[1]东北大学冶金学院,辽宁沈阳110819

出　　处：《过程工程学报》2022年第8期1074-1084,共11页The Chinese Journal of Process Engineering

基　　金：国家自然科学基金资助项目(编号:52104324,52171031);中央高校基本科研业务费(编号:N2025020)。

摘　　要：宏观偏析现象普遍存在于电渣重熔钢锭中,严重影响钢锭的均质性和凝固质量。建立了电渣重熔H13模具钢的三维瞬态耦合模型,对碳偏析现象进行模拟研究,并考虑合金元素间的相互影响。采用各向异性多孔介质模型模拟糊状区的动量衰减,Lever算法计算溶质再分配行为。模拟结果表明,碳元素富集在熔池底部,且随钢锭凝固而增多。重熔钢锭底部和边缘呈负偏析,中心和上部呈正偏析。在其他初始元素一定时,硅初始质量分数由0.8wt%增大至1.2wt%,碳元素正偏析指数增大了8.57%;钼初始质量分数由1.1wt%增大至1.75wt%,碳元素正偏析指数下降了1.89%,并且增加硅、钼元素初始质量分数可以使碳元素分布变得更为均匀;工作电流由3700 A降低至3100 A,重熔钢锭碳含量正偏析指数由0.0856降到0.0837,下降2.22%。Macrosegregation generally exists in the electroslag remelting(ESR) ingot, which seriously affects the homogeneity and quality of the ingot. A three-dimensional unsteady ESR mathematical model was established to study the macrosegregation phenomenon during ESR of large H13 die steel, and the interaction between alloying elements was considered. The anisotropic porous media model was used to simulate the momentum attenuation in the mushy zone. And solute redistribution behavior was calculated by the lever algorithm. The accuracy of the model was verified by experiments, and the distribution trend of carbon segregation index between simulation results and experimental results agree well. The simulation results showed that, at the beginning of melting, the metal pool was shallow and flat, and the metal rapidly solidified under the action of the cooling water in the bottom tank. With the progress of melting, the cooling effect of the bottom tank was weaker than the sidewall of the crystallizer, the metal pool profile deepened, and the carbon element was enriched at the bottom of the metal pool, and the concentration increased gradually. The bottom and edge of the ESR ingot showed negative segregation, while the center and top showed positive segregation. And the distribution of carbon segregation in ESR ingot did not change whether the initial element mass fraction and operating current were changed or not. When other initial elements were constant, the initial mass fraction of silicon increased from 0.8wt% to 1.2wt%, and the positive segregation index of carbon increased by 8.57%;The initial mass fraction of molybdenum increased from 1.1wt% to 1.75wt%, and the positive segregation index of carbon decreased by 1.89%. Under the condition of increasing the initial mass fraction of silicon and molybdenum, the distribution of carbon can be more uniform. When the working current decreased from 3700 A to 3100 A, the maximum positive segregation index of carbon decreased from 0.0856 to 0.0837, decreasing by2.22%.

关 键 词：电渣重熔 宏观偏析 数值模拟 溶质传输 熔池形状 

分 类 号：TF142[冶金工程—冶金物理化学]