Thermal Elasto-plastic Stress Analysis of Solidifying Shell in Continuous Casting Mold

Abstract

Temperature- and Stress-field in solidifying shell, and air gap formation in continuous casting mold have been numerically investigated by using a mathematical model to find conditions for strand-casting defect-free slabs. The model is based on a two dimensional non-steady state heat transfer analysis connected with a two dimensional thermal elasto-plastic stress analysis, and is capable of including the interaction between the temperature- and the stress-field. The model also involves operating variables, such as slab size, withdrawal rate, casting temperature, rate of water cooling in mold, mold taper, and, in particular, characteristics of mold flux.
Calculated variation of heat flux along the mold height agrees well with experimental one. Also, calculated shell profile, which exhibits retarded solidification owing to the formation of air gap near the corner of the shell, closely resembles experimental one.
The model developed in the present work has enabled us to get comprehensive information on the mode of solidification in continuous casting mold under varying casting conditions without making elaborating experiments. The model has been utilized as a potential simulator to determine optimum casting conditions for strand casting a variety of steels at high withdrawal rate.