Thermal mechanical behaviour during init

A transient finite-element model (CON2D) is employed to analyze the thermal-mechanical behavior during the initial solidification phase in continuous casting, with a focus on the effects of different steel grades. The model accounts for temperature-dependent material properties, thermal shrinkage, phase transformations, and utilizes distinct elastic-viscoplastic constitutive equations corresponding to each phase (liquid, solid, etc.). Simulations addressing fluctuations in metal level during casting reveal that greater depth of level drop results in increased distortion of the solidifying shell's tip, notably curving it away from the mold wall. This increased curvature is particularly pronounced for ultra-low-carbon (ULC) and peritectic steels, whereas low- and high-carbon steels exhibit a reduced distortion effect. These findings correspond with existing plant observations regarding the relationship between oscillation mark depth and steel grade. The results suggest that thermal distortion significantly influences the shape of oscillation marks on the lower side, and this effect is exacerbated by level fluctuations during the casting process.