【摘要】：硅鋼作為變壓器鐵芯不可或缺的材料,廣泛應用于電力設備中,其擁有良好的軟磁性能,特別地,當硅含量達到6.5wt%時,磁致伸縮幾乎為零,低鐵損、高矯頑力,幾乎是完美的電工鋼材料。CVD法是目前唯一實現(xiàn)工業(yè)化生產(chǎn)高硅鋼的方法。本文基于CVD法制備高硅鋼的原理,提出了晶界擴散在硅綜合擴散中的重要作用,構建了一種硅體擴散和晶界擴散相結合的數(shù)值模型用于預測滲硅過程中硅含量的分布,并且分析了基材的前處理對滲硅效率的影響,對實現(xiàn)高硅鋼的工業(yè)化生產(chǎn)有著重要的參考價值�；贑VD法要求搭建了實驗室制備高硅鋼的設備,測定了管式爐的低溫和高溫恒溫區(qū),確定了反應氣SiCl4濃度與水浴鍋溫度的數(shù)值關系,確定其與載氣N2流量無關。介紹了實驗的操作以及工藝參數(shù)的控制方式,在真空管式爐內(nèi)進行CVD滲硅實驗,利用掃描電子顯微鏡(SEM)和能譜儀(EDS)沿滲硅深度方向定量測量了樣品晶界附近和晶粒內(nèi)部的硅含量,發(fā)現(xiàn)晶界附近的硅濃度以及滲透深度明顯高于晶內(nèi),說明晶界起到了快速擴散通道的作用。利用SEM和金相分析軟件得到了晶界寬度及晶粒大小等微觀參數(shù)并將其應用于幾何建模,基于Voronoi圖原理,在Matlab和ABAQUS軟件環(huán)境下建立了硅擴散模型。采用Boltzmann-Matano求取體擴散系數(shù),并將其代入模型計算;對比實驗和模擬的平均硅含量值得到了 1100℃和1200℃下的晶界擴散系數(shù),其比體擴散系數(shù)高103～104倍,經(jīng)過驗證,模型很好的預測了硅含量的分布。對基材進行熱處理,探究了溫度、保溫時間和加熱方式對晶粒大小的影響;通過對比基材退火前后滲硅的差異發(fā)現(xiàn),冷軋板比熱處理后的基材滲硅效率高;建立了基材平均硅含量和滲硅時間的關系式,對構建連續(xù)性滲硅裝置有著重要的指導意義。
[Abstract]:As an indispensable material for transformer core, silicon steel is widely used in power equipment. It has good soft magnetic properties. In particular, when silicon content reaches 6.5 wt%, magnetostriction is almost zero, low iron loss and high coercivity. Almost perfect electrical steel material. CVD method is the only way to produce high silicon steel. Based on the principle of preparing high silicon steel by CVD method, the important role of grain boundary diffusion in silicon comprehensive diffusion is put forward in this paper. A numerical model combining silicon diffusion and grain boundary diffusion is constructed to predict the distribution of silicon content in siliconizing process. The effect of pretreatment on the efficiency of siliconizing is analyzed, which has important reference value for realizing the industrialized production of high silicon steel. Based on the requirement of CVD method, a laboratory equipment for preparing high silicon steel was built, and the low and high temperature constant temperature regions of the tube furnace were measured. The numerical relationship between the reaction gas SiCl4 concentration and the temperature of the water bath pot was determined, and it was determined that it was independent of the N 2 flow rate of the carrier gas. The operation of the experiment and the control mode of the process parameters are introduced. The CVD siliconizing experiment is carried out in the vacuum tube furnace. The silicon content near and inside the grain boundary was measured quantitatively by scanning electron microscope (SEM) and energy spectrometer (EDS) along the direction of the depth of siliconizing. It was found that the concentration and penetration depth of silicon near the grain boundary was obviously higher than that in the crystal. The results show that the grain boundary acts as a fast diffusion channel. The microcosmic parameters such as grain boundary width and grain size were obtained by SEM and metallographic analysis software, and applied to geometric modeling. Based on the principle of Voronoi diagram, the silicon diffusion model was established under the environment of Matlab and ABAQUS software. The volume diffusion coefficient was calculated by Boltzmann-Matano, and calculated by the model. The average silicon content in the comparison experiment and simulation is worth the grain boundary diffusion coefficient at 1100 鈩，

本文編號：2214721