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...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℃,and the solidification position shortens by about 0.11 m.As the superheat increases from 10 to 40℃,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%.展开更多
Nickel-based superalloy lattice sandwich structures present higher stiffness,higher strength and higher temperature resistance in comparison with other metals.In this study,the Kagome unit was adopted to design the la...Nickel-based superalloy lattice sandwich structures present higher stiffness,higher strength and higher temperature resistance in comparison with other metals.In this study,the Kagome unit was adopted to design the lattice sandwich structure and ProCAST software was used to simulate the filling and solidification processes of the nickel-based superalloy.Grain morphology and sizes of the nickel-based superalloy lattice sandwich structures were simulated by using of cellular automaton coupled with finite element model(CAFE),and indirect additive manufacture combining with investment casting were carried out to fabricate the nickel-based superalloy lattice sandwich structures.The calculated grain morphology and sizes are in good agreement with the experimental results.The grains are mainly equiaxed with an average size of about 500µm.The simulated results also show that the superheat of melting and the mold preheated temperature have significant influence on the grain size of the Kagome lattice sandwich structures,lower superheat of melting and mold preheated temperatures are encouraged to obtain the fine grains while assuring the integrity of the Kagome lattice sandwich structures for industrial application.展开更多
文摘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℃,and the solidification position shortens by about 0.11 m.As the superheat increases from 10 to 40℃,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%.
基金financially supported by the National Science and Technology Major Project of China(No.2017ZA04014001)the Natural Science Foundation of Liaoning Province of China(Nos.2019-ZD-0997,20170540890)the Technology Development Fund of China Academy of Machinery Science and Technology(No.170217ZS01)
文摘Nickel-based superalloy lattice sandwich structures present higher stiffness,higher strength and higher temperature resistance in comparison with other metals.In this study,the Kagome unit was adopted to design the lattice sandwich structure and ProCAST software was used to simulate the filling and solidification processes of the nickel-based superalloy.Grain morphology and sizes of the nickel-based superalloy lattice sandwich structures were simulated by using of cellular automaton coupled with finite element model(CAFE),and indirect additive manufacture combining with investment casting were carried out to fabricate the nickel-based superalloy lattice sandwich structures.The calculated grain morphology and sizes are in good agreement with the experimental results.The grains are mainly equiaxed with an average size of about 500µm.The simulated results also show that the superheat of melting and the mold preheated temperature have significant influence on the grain size of the Kagome lattice sandwich structures,lower superheat of melting and mold preheated temperatures are encouraged to obtain the fine grains while assuring the integrity of the Kagome lattice sandwich structures for industrial application.
