The Simulation Of Continuously Casting Process Of7A04Aluminum Ingots

In this paper, continuous casting ingot with diameter380and hollowingot with the diameter380/67were simulated by simulation softwareProCAST. To establish the model of temperature field in casting process, bychanging the pouring temperature, casting speed, cooling intensity, mold heightand mold wall thickness, and analyzes its influence on the temperature fielddistribution and the sump depth during casting.The simulation results show that, in the process of continuous casting,mould temperature variation can be divided into four stages: the initial casting,mold temperature rises rapidly; then the mould temperature decreases; startdrawing but the ingot not yet out of air cooling, mold temperature increased,with the dummy bar head drop, fresh high temperature aluminum liquidsupplement since casting, the mold temperature is rising again; the billet intosecondary cooling zone, amount of cooling water direct injection on the outersurface of billet, billet temperature decreased rapidly under the combined actionof a direct cooling water and the secondary cooling water, mold temperaturegradually decreased; When the dynamic equilibrium between the mold and themolten aluminum, the mould temperature to stabilize.Casting temperature is constant: the mold from top to bottom, thetemperature decreased; while not entering the secondary cooling zone, thetemperature decreases from top to bottom of the billet, but into the secondarycooling zone for some time, due to the strength of the secondary cooling zone isvery large, so that the surface temperature of the billet tends to be close. Thetemperature of the billet center decline slowest, with close to the edge, thetemperature drop faster. Ingots of different cross-section, the cross-section fromthe entrance the more distant, the faster the temperature drops.Increasing the pouring temperature or the casting speed, the temperature ofthe same position on the same cross-section increases, the greater thetemperature difference between inside and outside of the billet, the deeper sump;when increasing the cooling water strength, the internal and edge temperature drop rate of the ingot increases, the temperature at the same location on thesame cross-section is relatively low, the smaller the temperature differencebetween inside and outside the billet, the more shallow the sump.The higher the mold, the lower the temperature of the billet outer wallmid-point When the billet is not out of the mold. After the mold, the higher mold,the higher temperature of the billet mid-point. In the mold, the lower mold, thecloser the tip of the intermediate crystal pitch, so the higher the temperature.But the lower mold, the mid-point into the secondary cooling zone sooner, thusthe earlier the speeding up of billet cooling rate after the mold, at the same time,the lower mold, the lower the temperature of the billet mid-point. With theconduct of casting, the billet temperature under different converge mold height.The higher the mold, the molten aluminum temperature dropped more from intoand out of the mold.