Analysis of solidification simulation results of sand castings

After the simulation calculation is completed, enter the visual viewer post-processing interface, observe the dynamic change of liquid metal temperature field through temperature in the thermal option, and select the node element corresponding to the thermocouple position in the sand casting in the evolution / profile menu bar of the main interface. The temperature measuring point is located at half of the wall thickness of the ring sand casting. In the ring sand casting, the point point1 with the same position as the actual sand casting Tc1 is selected as the node element. The node selection is shown in Figure 1.

It can be seen from Figure 2 that the difference between the simulated temperature field and the measured temperature using the inverse calculated interface heat transfer coefficient is very small, and the simulated temperature is basically consistent with the measured temperature before the solidification process is completed; After the temperature of the sand casting drops below the solidus, there is a slight deviation between the simulated temperature and the measured temperature, and the maximum temperature difference between the simulated temperature and the measured temperature of the annular sand casting is about 17 โ„ƒ, which also shows that there is a slight deviation between the interface heat transfer coefficient obtained by inverse calculation and the actual interface heat transfer coefficient after the solidus temperature is below the solidus temperature; Since the air gap layer formed at the inner and outer interfaces of the annular sand casting is assumed to remain unchanged after the liquid metal is completely solidified, in fact, after the sand casting is completely solidified, there will be a little cooling shrinkage in the cooling process of the casting, sand mold and sand core, so that the change of the air gap layer leads to a little change in the interfacial heat transfer coefficient, and the neglect of this process leads to temperature error, The error of temperature field after complete solidification of sand casting will not have much influence on the prediction of sand casting defects by the simulation software. Therefore, we can regard the interface heat transfer coefficient below the solidus temperature as a constant, which will not affect the prediction of simulated defects while simplifying the simulation process of sand casting.

Through the analysis of the above data, the interface heat transfer coefficient obtained by the back calculation program can be used in ProCAST simulation to obtain reliable temperature field calculation results. Therefore, it further confirms the accuracy and reliability of the interface heat transfer coefficient obtained by the back calculation program, and effectively improves the accuracy of ProCAST simulation.

spacer