Influence of nonmetallic inclusions in rail steel on the high-temperature plasticity

Resumo

The influence of nonmetallic inclusions in Э76Ф rail steel on the high-temperature plasticity is considered. In terms of the shear strain, a plasticity maximum is observed in all three zones of the continuouscast billet: the crust, the columnar-crystal zone, and the central zone of the billet. The high-temperature torsion of samples heated to 950–1250°C with 10-min holding is studied for continuous-cast billet of electrosmelted rail steel. Oxides and silicates are present in the crust; oxides and oxysilicates are found in the columnar-crystal zone; and sulfides, oxides, silicates, and alumosilicates are found in the central zone of the billet. The concentration of inclusions that impair the plasticity is greatest in the central zone of the billet.