Serious defects in the continuous casting of steel, including surface cracks and depressions, are often related to thermal mechanical behavior during solidification in the mold. A finite-element model has been developed to simulate the temperature, shape, and stress of the steel shell, as it moves down the mold in a state of generalized plane strain at the casting speed. The thermal model simulates transient heat transfer in the solidifying steel and between the shell and mold wall. The thermal model is coupled with a stress model that features temperature-, composition-, and phase dependent elastic-visco-plastic constitutive behavior of the steel, accounting for liquid, δ-ferrite, and γ-austenite behavior. Depressions are predicted to form when the shell is subjected to either excessive compression or tension, but the shapes, severity, and appearance differ with conditions. Cracks appearing without depressions are suggested to form in the lower ductility trough when the shell is colder but more brittle. The local thickness of the shell and austenite layer appears to have major effects as well. The model reveals new insights into the formation mechanisms and behavior of surface depressions and longitudinal cracks in the continuous casting process.

No abstract

No abstract

Understanding and improving complex manufacturing processes such as steel continuous casting can have a tremendous global impact. Due to the extremely harsh environments, computational modeling is more important than ever in the study of these processes. Being able to visualize the model results in a manner that conveys accurate process understanding as well as being visually digestible can be difficult, especially for transient, three‐dimensional models. Depending on the objective, it is also important to distinguish between graphically‐pleasing and physically‐based visualization. Following physically‐based visualization guidelines can help make the model results easier to understand and interpret. Examples include: color maps based on temperature, glyphs to show multiple stress components, vector plots overlaying a scalar field, diverging and discrete color maps to differentiate tension and compression, and orienting figures so that gravity acts downwards. This paper explores methodologies for post processing, as well as the selection of some visualization parameters, for a variety of variables and models relevant to understanding and quantifying the complex phenomena in steel continuous casting. Finally a methodology is introduced for the processing of high‐density data from temperature sensors to better visualize potential quality issues on the surface of a continuously cast slab.