Physical And Mathematical Modeling Of Big Steel Ingot Casting With Argon Blowing

This paper focuses on the effects of the bottom argon blowing process on the flow field of an ingot mold during the filling process by applying physical and mathematical modeling.Specifically,the effects of different blowing flow rates and positions on the mixing times at different surface heights were studied when one or double gas porous beams.In addition,the mixing time,the velocity field and inclusions removal rate in the optimized scheme were calculated by the mathematical modeling.The experiment was carried out with a physical model which is scaled down by 1:3.The results showed that a long time is needed to get homogenous without gas blowing for the bath of the ingot model and the time is increased when the filling height is increased.A remarkable decrease in mixing time could be found with gas blowing in the model.The mixing times range from 25 to 46s when a gas porous beam is located at a distance of 62mm from the nozzle center for one-side blowing.When two-side blowing gas porous beams were used,the mixing times vary between 18 and 46s and a better effect can be acquired when the beams were located at a distance of 102mm from the filling bottom center.Consequently,it was recommended that the blowing flow rate was 0.025m3/h and 0.035m3/h or 0.045m3/h when the filling heights are lower and higher than 300mm,respectively.In the mathematical modeling,the results obtained were verified by comparing the spout heights,mixing times to those of the physical model.The effects of different blowing flow rates on the mixing times and flow fields in the physical model were investigated by mathematical modeling.The results showed that the flow field in the optimized scheme with bottom argon blowing was more well-distributed compared to that of the original scheme without argon blowing.Meanwhile,the results also showed that it is favorable for the inclusions removal by introducing argon blowing in the ingot casting process.Comparing to the case without argon blowing,the inclusions removal rates have been increased by 6.94%and 3.97%for the filling heights of 1500 and 2780mm,respectively.