The structure formation features of carbon and low alloyed steels during cooling of the ingot and continuous cast billets

The investigation of the features of formation of austenite grains, ferrite and pearlite structure during the cooling process of the ingot and cast billets made of carbon and low-alloyed steels; the assessment of the contamination level by nonmetallic inclusions of the bottom casting ingot Ø 485 mm (open-hearth process of making steel) and continuous cast billets Ø 470 and 450 mm (EAF steelmaking process). Methodology. The metallographic methods of detection and determination of grain size and non-metallic inclusions. Findings. It has been determined that the microstructure of the continuous cast billets for the production of railway wheels has smaller austenitic grain, more uniform distribution of pro-eutectoid ferrite, lower content of non-metallic inclusions as compared with the microstructure of the ingot. Originality. It has been established that carbon content in the steel, along with the cooling rate, is one of the main factors defining the parameters of the microstructure during the solidification of the continuous cast billets. Practical value. The radical change in production technology and the replacement of an ingot to a continuous cast billet will significantly improve the quality as an original billet and finished steel products.