真空感应熔炼实验结束后，在每炉实验的铸锭上取样。每个铸锭的取样位置相同。对样品样进行镶样、粗磨、细磨、抛光后。采用SEM-EDS观察合金试样的夹杂物，对于每种类型的夹杂物，至少观察20个。采用夹杂物自动分析设备SEM(ZEISS, EVO18)-EDS (Oxford, INCA)对合金试样的夹杂物进行更大面积上的统计分析。设定最小夹杂物为1μm。因此尺寸大于1μm的夹杂物信息才能被收集。对于每个合金，从不同部位取样进行自动分析，总面积为144mm2。利用公式计算夹杂物的数量密度(number density，简称ND)和面积百分数(area fraction，简称AF)。最后利用origin绘图软件绘制夹杂物数量密度随熔炼时间的变化曲线。

After the vacuum induction smelting experiment is completed, samples are taken from the ingots of each batch of the experiment. The sampling positions of each ingot are the same. After the sample is inlaid, roughly ground, finely ground and polished. The inclusions in the alloy specimens were observed by SEM-EDS. For each type of inclusions, at least 20 were observed. The inclusions in the alloy specimens were statistically analyzed on a larger area by using the inclusion automatic analysis equipment SEM(ZEISS, EVO18)-EDS (Oxford, INCA). Set the minimum inclusions to 1μm. Therefore, the information of inclusions with a size greater than 1μm can be collected. For each alloy, samples were taken from different parts for automatic analysis, with a total area of 144mm ². The number density (ND for short) and area fraction (AF for short) of inclusions are calculated by using the formula. Finally, the variation curve of the quantity density of inclusions with the melting time was plotted using the origin plotting software.