Effect of Mold Electromagnetic Stirring on the Gear Steel Solidification Behavior of Its Large-sized Round Casting

doi:10.3901/JME.2021.02.105

Abstract

Abstract: Mold metallurgy is a key aspect for the control of solidification in continuous casting process and the final product quality of special steel. Based on the φ 650 mm large-sized round casting process for 42CrMo steel semi-products,the initial solidification behavior with mold electromagnetic stirrer(M-EMS) and its installation have been studied by aids of a three-dimensional coupled model for the complex magnetic, fluid flow, heat transfer and solidification behavior. The results show that the copper tube of the mold has a magnetic shielding effect, which leads to a higher working efficiency of the stirrer can only be achieved by its lower installation position. Electromagnetic stirring can reduce the jet flow impingement on the initial shell through the side-ports of the nozzle, which can enhance the superheat dissipation and intensify meniscus fluctuations. As the stirrer installation position moves downward from 330 mm to 730 mm, the maximum meniscus level fluctuation is reduced by 2.5 mm, and the maximum tangential velocity of liquid steel at solidification front is increased by 0.069 m/s, the location of zero superheat degree of the center molten steel moves down by 0.159 m, and the range of uneven shell thickness at mold exit is reduced by 1.1 mm. It is suggested that when the M-EMS is installed at 530 mm below the meniscus, it is not only beneficial to the control of the mold level fluctuation and the uniformity of the shell growth for an improved surface quality of the strand, but also beneficial to the formation of equiaxed crystal owing to the dissipation of superheat at mold exit.

Key words: high-strength gear steel, large-sized round casting, M-EMS installation, mold level fluctuation, superheat dissipation

CLC Number:

TF777

WANG Pu, XIAO Hong, SHEN Houfa, CHEN Xiqing, CHEN Lie, LAN Peng, ZHANG Jiaquan. Effect of Mold Electromagnetic Stirring on the Gear Steel Solidification Behavior of Its Large-sized Round Casting[J]. Journal of Mechanical Engineering, 2021, 57(2): 105-111.

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