Numerical simulation on solidification behavior and structure of 38CrMoAl large round bloom using CAFE model

A coupled cellular automaton-finite element model was developed to simulate the solidification behavior and structure of 38CrMoAl large round bloom, in which mold electromagnetic stirring + final electromagnetic stirring was taken into consideration, under different superheat, casting speeds, and secondary cooling water flow. Industrial trials for infrared temperature measurement and macro etch experiments of the post-test round bloom samples were used to verify the simulated solidification structure and temperature field. The simulation results show that superheat and secondary cooling water flow have little influence on the surface temperature, center temperature, and center solid fraction while casting speed has a more obvious influence on solidification behavior. With the increase in the casting speed of 0.02 m min(-1), the solidification position is prolonged by about 1.64 m. With the increasing specific water ratio by 0.02 L kg(-1) each, the surface temperature of the secondary cooling zones decreases by about 18 degrees C, and the solidification position shortens by about 0.11 m. As the superheat increases from 10 to 40 degrees C, the ratio of the equiaxed crystal zone decreases from 35.98% to 23.98%. The casting speed and secondary cooling water flow increase the equiaxed crystal ratios of the large round bloom, but neither is significant, both being about 2%.