基于实验与3D—CAFE法的高硅钢铸锭凝固行为

发布时间：2018-03-10 19:30

本文选题：硅钢　切入点：凝固　出处：《工程科学学报》2017年03期 　论文类型：期刊论文

【摘要】：通过空冷和水冷实验研究了高硅钢的铸态组织,发现高硅钢铸态组织主要由粗大的柱状晶构成,水冷铸锭中柱状晶比例高达90%以上.依据铸锭的化学成分和晶粒统计结果,确定了3D-CAFE法模拟所需的枝晶生长动力学系数及高斯分布等参数.采用CAFE法对不同冷却条件下高硅钢的凝固过程进行模拟研究,发现空冷铸锭较水冷铸锭的温度场更均匀,糊状区更宽阔;空冷铸锭呈"过渡式"凝固,水冷铸锭呈"分层式"凝固;空冷流场较水冷流场更稳定,凝固末期冒口处出现明显的抽吸现象,而水冷模拟结果中未观察到该现象.组织模拟结果发现,模拟得到的高硅钢凝固组织无论是形貌还是晶粒尺寸都与实验结果相一致;最后通过改变浇注温度模拟研究了过热度对高硅钢凝固组织的影响,结果表明,随着过热度的降低,铸锭中心等轴晶率提高,晶粒数量增加,晶粒尺寸变得细小.
[Abstract]:The as-cast structure of high silicon steel was studied by air-cooling and water-cooling experiments. It was found that the as-cast structure of high silicon steel was mainly composed of coarse columnar crystals, and the ratio of columnar crystals in water-cooled ingot was more than 90%. Based on the results of chemical composition and grain statistics of the ingot, The parameters of dendritic growth kinetic coefficient and Gao Si distribution for 3D-CAFE simulation were determined. The solidification process of high silicon steel under different cooling conditions was simulated by CAFE method. It was found that the temperature field of air-cooled ingot was more uniform than that of water-cooled ingot. The gelatinization zone is wider, the air-cooled ingot is "transitional" solidification, the water-cooled ingot is "stratified" solidification, the air-cooled flow field is more stable than the water-cooled flow field, and the suction phenomenon appears at the riser at the end of solidification. However, this phenomenon was not observed in the simulation results of water cooling. The results of microstructure simulation showed that both the morphology and the grain size of the solidified microstructure of high silicon steel obtained by simulation were consistent with the experimental results. Finally, the effect of superheat on solidification structure of high silicon steel was studied by changing the pouring temperature. The results showed that with the decrease of superheat, the equiaxed crystal ratio in the center of ingot increased, the number of grains increased and the grain size became fine.
【作者单位】：北京科技大学钢铁冶金新技术国家重点实验室;
【分类号】：TG260

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