目的 研究渗硅过程中的晶界占比对渗硅质量的影响，从而探究出制备6.5%Si硅钢的合理工艺。 方法 通过CVD法，利用真空管式炉制备6.5%Si硅钢。通过高温金相实验探究温度对晶粒尺寸的影响，利用高温与常温下的金相实验、扫描电镜(SEM)和能谱分析(EDS)分别统计平均晶粒尺寸、平均晶界宽度和扩散方向上晶粒内部与晶界上的硅含量，再利用MATLAB和Abaqus软件求解扩散系数和模拟分析微观渗硅。结果 1200 ℃下反应60 s，再扩散至140 s时，平均晶粒尺寸为140.45 μm，平均晶界宽度为76.31 nm，由实验数据计算得到的晶粒内部扩散系数为9.026×10^–6 mm²/s，晶界扩散系数为2.924×10^–3 mm²/s，晶界占比为0.163%。结论 晶界会影响渗硅扩散的速率与时间，晶界占总体积的比例越高，硅扩散越快，但相同时间内扩散越不均匀，导致硅钢片塑性下降。

This paper aims to study the influence of the proportion of grain boundaries in the siliconizing process on the siliconizing quality, so as to explore a reasonable process for preparing 6.5% Si silicon steel. through the preparation of 6.5% Si silicon steel by CVD method, this paper utilizes a vacuum tube furnace to prepare 6.5% Si silicon steel, utilizes high-temperature metallographic experiments to investigate the effect of temperature on grain size, respectively utilizes metallographic experiments, scanning electron microscopy (SEM), and energy spectroscopy (EDS) to count the average grain size, average grain boundary width, and silicon mass fraction in the grain and the grain boundary along the diffusion direction, and then utilizes MATLAB and Abaqus software to solve diffusion coefficients and perform microscopic silicon infiltration simulation analysis. The result indicate that the average grain size is 140.45 μm, and the average grain boundary width is 76.31 nm when reacted for 60 s and diffused for 140 s at 1200 ℃. The internal diffusion coefficient calculated from the experimental data is 9.026×10–6 mm2/s, the grain boundary diffusion coefficient is 2.924×10–3 mm2/s, and the proportion of grain boundaries is 0.163%. Therefore, it can be concluded that the grain boundaries will affect the rate and time of silicon diffusion. The higher the proportion of grain boundaries in the total volume is, the faster the silicon diffusion will be, but the more uneven the diffusion is within the same time, thus resulting in a decrease in the plasticity of the silicon steel sheet.