Thermo-mechnical Behavior Of Slab And Mold Based On Measurements In Slab Continuous Casting

As an important component of continuous casting machine, Uniformity and stability heat transfer conditions in mold are premise for stable operation of the casting machine and efficient production.It is plays an important role for control the initial solidification behavior of liquid steel to research heat and mechanical behavior occurs in the mold.For wide and thick slab continuous casting production process, In order to acquire the relevant laws of wide and thick plate mold heat transfer processes and characteristics, to explore factors affecting heat mold and control channels.Therefore, this paper use the date from a casting machine in a steel mill, for example, accumulated one year of casting data for detection and recording, respectively, discuss the impact of casting speed, superheat, inlet water temperature and other factors on heat flow in the mold. The results show that the mold flux increases with the rise of casting speed, increased to more than1.05m/min when the heat is no longer increasing, while the carbon content of0.13%in the crystallizer heat to a minimum, which indicated we need to design a rational a cold and mold powder process to form slow cooling to prevent the longitudinal and other defects.In a domestic steel mill continuous casting slab mold for the study, based on the measured data of copper mold temperature detection system, through the establishment of the mold/strand solidification inverse problem of heat transfer model, using the measured temperature inverse mold/slab heat flux. On this basis, create finite element model for mold based ANSYS. Carefully consider the impact of the model tank, coating of mold heat transfer, Between the mold hot surface and the slab with inverse heat flux as boundary conditions, based on mobile two-dimensional slice method to calculation mold temperature field. The results show, ANSYS simulation results are consistent with the results of inverse process proceeds, confirms the reliability of the inverse problem of heat transfer model. When the slab appears longitudinal crack, mold width direction of the surface temperature fluctuates significantly; In contrast, in normal conditions, the mold temperature is relatively uniform, no significant fluctuations. From the hot surface to the cold, the temperature distribution of copper is substantially parallel isotherms, In the area of copper cooling tank temperature curve arched, the root of deep tank cooler than the root of shallow tank water of a high temperature10℃.Using ANSYS to establish a two-dimensional transient model of slab solidification process, taking casting speed as slice movement speed, the solidification and stress state of slab from meniscus to mold exit are simulated. We use the simulation results of temperature field as the body load, considering the influence of the static pressure of liquid steel on the stress distribution. The stress distribution of slab is computed by using the coupling method. The results show that the temperature distribution at the same distance from meniscus fluctuate significantly when longitudinal cracks appear, however, the temperature distribution are relatively uniform under normal working condition. The actual position of longitudinal crack occurred is in the area of shell temperature and thickness sharply transited. According to the longitudinal crack criterion, the rapid solidification area of shell produces tensile stress on the surrounding shell, meanwhile the stress still have an effect in the near range, if the high temperature tensile strength of shell is lower than the stress, the crack will be generated.