A mathematic model for solidification process of 35 t polygonal ingot of 40CrNiMo steel (/% : 0.37-0.44C
0.17-0.34Si
0.50-0.80Mn
≤0.035P
≤0.035S
0. 60-0.90Cr
1.25-1.65Ni
0.15-0.25Mo) has been established by using three-dimensional software Procast to simulate the ingot temperature field and steel shrinkage rate during pouring (for 1313 s) and mold-filling solidification (for 73942 s) process. Results show that the simulation-calculated complete solidification time of ingot-20.5 h is basically the same as measured solidification time of ingot in situ-22 h; the shrink rate of steel is ≤2.5%
the cast ingot has no secondary pipe and only has light porosity.