采用浸蚀法和电解抛光法对IF钢（DC06钢和CR5钢）进行制样，对比了2种方法的制样效果，并分析了浸蚀剂种类及浸蚀时间对制样效果的影响。结果表明：浸蚀法制样较电解抛光法简单，但浸蚀法需要通过多次试验才能确定最佳浸蚀时间；电解抛光法的制样过程复杂，但制样效果较好，可获得晶界清晰的试样；使用体积分数为4%的硝酸酒精溶液浸蚀DC06钢和CR5钢时，浸蚀效果均较差；对于碳质量分数大于1×10^-5的DC06钢，选用硫酸铜盐酸溶液浸蚀6，10 s后可以观察到清晰的铁素体晶界；对于碳质量分数小于1×10^-5的CR钢，用硫酸铜盐酸溶液的浸蚀效果较差，电解抛光效果较好。

The samples of IF steel (DC06 steel and CR5 steel) were prepared by etching and electrolytic polishing methods. The sample preparation effects of two methods were compared. The influences of the type of etchant and etching time on sample preparation effect were analyzed. The results show that the sample preparation by etching was simpler than that by electrolytic polishing, but the best etching time need to be determined through many tests. The sample preparation process of electrolytic polishing was complex, but the sample preparation effect was good, and the sample with clear grain boundary could be obtained. The etching effects were poor when the DC06 steel and CR5 steel were etched by 4% nitric acid alcohol solution. The clear ferrite grain boundaries of DC06 steel with carbon mass fraction grater than 1×10^-5 could be observed after etching with cupric sulfate hydrochloric acid solution for 6, 10 s. The etching effect was poor of CR5 steel with carbon mass fraction less than 1×10^-5 after etching with cupric sulfate hydrochloric acid solution, and the electrolytic polishing effect was good.