Effect of Casting Temperature on Continuously-Cast Bearing Steel GCr15 Billet Structure Formation

Modeling is conducted for solidification and formation of a cast structure of continuously-cast blooms of steel GCr15 (Russian analog is steel ShKh15). A finite element method is used in order to model the formation of the crystal structure of continuously-cast blooms. Solidification is modelled for a bloom of steel GCr15 470 × 350 mm in cross section with different values of steel overheating above the liquidus line. Results of modeling are used for simulating continuously-cast billet macrostructure. It is shown that with a reduction in casting temperature the extent of the columnar crystal zone is reduced gradually within the structure, the extent of the skin and equiaxed zones is expanded, grain density increases gradually, and the maximum grain area and radius are significantly reduced. There are no small size fine dendritic crystals within the center of the equiaxed grain zone.