Abstract
Solute segregation and formation of non-metallic inclusions during the solidification of a titanium-containing steel are modeled in this paper. The Ueshima model was used to describe the partitioning of solute elements in the steel, taking account of back-diffusion into the solid. Calculations were made for solidification of an AH-36-3u steel ingot cooled at 50 or 100 K min⁻¹. The simulations reveal that MnS inclusions are formed first, followed by TiN, Ti₂O₃ and SiO₂. Increased cooling rate accelerates the formation of non-metallic inclusions, but for the assumed rates of 50 and 100 K min⁻¹ the differences in amount formed are minimal. The results of these calculations for AH-36-3u steel give an approximate picture of the distribution of inclusions in the solidified ingot structure.

Key words
segregation, ingot solidification, non-metallic inclusions, back-diffusion

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