Increasing the efficiency of bar of high-quality steel ingots

The effect of various heat insulators for the head lateral surface on the development of chemical inhomogeneity of the ingot top is investigated on the 580 kg ingots of one and the same melting of the 45 steel in the earth molds. The impurity liquation in the axial zone of the ingots decreases with the increase in heat isolating efficiency of the head. In the head of the ingots the zones of the negative carbon liquation located near their surface are found. The carbon balance in the ingot top shows that 40-60% of the excess amount of carbon under the contraction cavity is taken from the negative liquation zones. On the commercial ingots of 4.5-6.5 t mass the possibility is established of decreasing the head volume by 3% at an average by utilizing the heat-insulating materials without deterioration of macrostructure and chemical homogeneity of the metal