Effect of Beracha-I type color etchant on the ferrite phase in different type Fe-C alloys

In material science, and particularly in metallography, various etching processes are frequently used to visualize grain structure. For some etching processes, it is sufficient to immerse the specimen into the etchant only for a few seconds, but for color etching, samples must be kept in the etchant for several minutes to achieve a colored surface layer. In our research, a measurement environment was created, in which the process of color etching can be observed in real-time. A closed microfluidic system ensured the controlled laminar flow of the etchant. The surface of the observed spherical graphite cast iron and DC01 low carbon steel was monitored from the beginning to the end of etching. Comparing the etching of the spherical graphite cast iron and the low carbon steel samples give a more comprehensive picture of the effect of Beraha-I type color etchant on the ferritic structure. Though the etchant reacts with the same ferritic phase in both cases, the etching process develops in different ways. The layer formation was much faster in the ferritic phase of DC01 steel, compared to ferrite in cast iron specimens.