The cloud diagram of solid phase distribution of vermicular cast iron is shown in Figure 1. From the solid phase nephogram, it can be seen that the solidification sequence of vermicular cast iron pressure plate casting is first from the inner circle and outer circle, then the middle plate surface, and finally the three lugs connected with the riser, forming a solidification sequence from two ends to the middle. This is because the interface between vermicular cast iron and the mold is cooled by the mold, so the heat dissipation is fast and the cooling speed is fast, so it solidifies first.
Because the compacted vermicular cast iron pressure plate is relatively symmetrical, two typical areas are selected, and then the nodes are selected for specific analysis. The solid rate values of the nodes (Fig. 2) are selected for sorting to make the solid rate time curve, as shown in Fig. 3.
From the solid fraction curve, it can be seen that the solidification sequence of compacted vermicular cast iron pressure plate is 1, 2 and 3. The complete solidification at point 1 is about 90s earlier than that at point 3. From the position of the pressure plate at points 1 to 3, the inner circle of the vermicular cast iron pressure plate (point 1) solidifies first, followed by the pressure plate surface (point 2), and the large lug connected with the riser (point 3) solidifies finally, forming a small range of sequential solidification from the inner circle to the large lug; Among points 4 to 6, points 4 and 6 solidify earlier than point 5. From the position of the pressure plate at points 4 to 6, the inner circle of the vermicular cast iron pressure plate (point 4) and the small lug (point 6) solidify first, and the difference in complete solidification time between the two is very small. The middle surface of the vermicular cast iron pressure plate (point 5) solidifies last, forming a close solidification from both ends to the middle, which corresponds to the solid-phase cloud diagram of vermicular cast iron.