The finite element analysis software ProCAST is used to simulate the flow field and temperature field in the iron mold sand coating process of nodular iron crankshaft, and predict and analyze the possible defects, so as to evaluate and optimize the process before tooling trial production.
- The finite element simulation calculation of the actual casting process of ZHY casting (pouring temperature 1420 ° C, sand shell thickness 6mm) shows that it takes 13s to complete the mold filling, and the crankshaft surface temperature drops to 600-700 ° C at 800s. The hot spot is judged according to the temperature field, and the shrinkage cavity casting defects are predicted. The results are basically consistent with the actual detection of ZHY casting.
- Explore the changes of temperature field and solidification time of castings under different pouring temperatures. At 1400 ° C, the cooling rate of the casting edge is fast, the solidification time of the crankshaft edge is only 0.4s, and the complete solidification of the surface takes 100s; At 1420 ° C and 1450 ° C, the edge solidification time needs about 40s and the surface complete solidification needs 200s. At 1400 ° C, the solidification speed of crankshaft is too fast, which is not conducive to the precipitation of graphite balls and reduce the feeding effect; At 1450 ° C, the cooling of the hot joint is slow, and the shrinkage cavity range at the hot joint is large; In contrast, 1420 ° C is the appropriate winding temperature.
- Explore the changes of temperature field and solidification time of castings under different sand shell thickness. When the thickness of sand shell is 4mm, the edge cooling speed is the fastest. When the thickness of sand shell is 6mm and 8mm, the temperature field changes little, and the solidification time is reasonable, which can be applied in practice. The thickness of sand shell can be selected according to the process conditions.