Effect of Precipitates on Surface Cracks in Continuous Casting of Steel

In recent years, the required properties of steel products are getting higher and higher, and the steel composition contains more alloy elements. Also, steelmakers are facing pressure to change their ironmaking & steelmaking processes to reduce CO2 emissions. In these environmental changes, maintaining and further improving the quality of casts produced by continuous casting are important issues. However, surface cracks in casts are greatly influenced by composition and thermal history. This is because one of the factors causing surface cracks is the influence of fine precipitates that form on austenite grain boundaries. Although the relationship between surface cracks and precipitates has been researched in the past, there have been few considerations using kinetic simulations. Therefore, this study evaluates the influence of precipitates on surface cracks from the calculation approach using MatCalc, which enables thermodynamic and kinetic simulations of precipitation in steel, and the experiment approach using IMC-B tests. These efforts are expected to develop strategies for the steel composition and process design and to improve the quality of cast even in the various environmental changes.