The chemical composition of molten metal is detected in front of the furnace, and the results are shown in Table 1. In order to reflect the influence of parameter changes on the simulation results, the actual components are input into ProCAST system, and the real-time nonlinear change curves of thermal conductivity and density of ZG25MnCrNiMo are calculated, as shown in the figure.
| Main chemical elements | C | Si | Mn | Cr | Ni | Mo | P | S | Fe |
| Regulations | 0.25-0.32 | 0.40-1.50 | 1.30-1.85 | 0.50-0.60 | 0.45-0.50 | 0.25-0.30 | ≤0.35 | ≤0.35 | — |
| Actual | 0.26 | 0.45 | 1.40 | 0.55 | 0.45 | 0.25 | ≤0.35 | ≤0.35 | 0ther |
The material of the mold shell is the shell molding sand mold material in the material warehouse, and the thickness of the mold shell is 8mm. Other investment casting pouring process parameters and boundary conditions are shown in Table 2. In scheme a, the investment casting pouring temperature is 1550 ℃ and the investment casting pouring time is 15s; Since the overall quality of scheme B is about 47% higher than that of scheme a, the pouring temperature of investment casting in scheme B is 1580 ℃ and the pouring time of investment casting is 30s.
| Parameters | Numerical value |
| Pouring temperature T1 / ℃ | 1550/1580 |
| Mold shell preheating temperature T2 / ℃ | 400 |
| Ambient temperature T0 / ℃ | 20～25 |
| Pouring time t / s | 15/30 |
| Heat exchange coefficient between mold shell and casting H1 / (w · m-2 · k-1) | 500 |
| Heat transfer coefficient between shell and air H2 / (w · m-2 · k-1) | 10 |
| Gating system / riser | 8 |
| Casting body | 5 |