Solidification simulation and shrinkage optimization of big flat ingots

The temperature of a steel ingot of 28.7 t was measured during solidification and the temperature field and solidification process of the steel ingot were simulated by a finite element method. It is shown that the simulated values of the temperature field agree well with the measured data, indicating that this simulation is accurate and reliable. At the initial stage of solidification, the bottom of the steel ingot and the connection zone between the ingot mold and the insulating riser solidify faster. At 52 min, an air gap forms between the steel ingot and the adiabatic plate. At the first 3 h, the steel ingot solidifies parallelly from the mold wall to the center. The later stage of solidification is faster than the early stage. The solidification time is 428 rain in the center of the insulating riser and the final solidification time is 365 min in the center of the ingot body. The former is 15% longer than the later, which is benefit to control shrinkage cavities in the insulating riser only. Based on the simulation, the pouring temperature reduces from 1543℃ to 1533℃, which does not affect steel feeding but also can reduce 6 mm of the depth of shrinkage. This method can improve the quality of steel ingots.