Microscope observations (with the optical microscope-polarized
light and the scanning microscope) of the C15 steel sample
surfaces carburized with the use of The FineCarb method revealed
the occurrence of the outlined grains of previously existing
austenite of different shade. For a sample after the boost steps only
the dominant shade of the grainswas gray with a few brighter areas
(optical microscope). In the scanning microscope image of the
grains these areas were darker. The diffusion steps led to a change
in the shade, which was especially visible when observing the
samples with the scanning microscope, which showed grains as
a gray shade.