The nature of change in the amount and morphology of iron dendrites and excess phases in relation to the degree of high-carbon alloy melt supercooling is considered. It is revealed that in pure iron-carbon alloys by changing the degree of melt supercooling it is possible to obtain steel with a carbon content as in white cast iron, or white cast iron with a carbon content as in steel. It is shown that before forging Damascus steel the structure is ideal with a pearlite matrix, without secondary free cementite, and with excess ledeburite phase. Features of ferrite and ledeburite shape change with thermomechanical treatment (forging) are studied. It is detected that during deformation heating for forging there is ledeburite recrystallization into a more stable phase of eutectic carbide. Limits are determined for transformation of pure high-carbon alloys in carbide class steel of the Damascus type.