Effect of Combined Stirring Modes on the Solidification Behavior of Special Steel Bloom Casting

doi:10.3901/JME.2020.12.099

Abstract

Abstract: The mold electromagnetic stirring(M-EMS) and final electromagnetic stirring(F-EMS) is widely used in the special steel bloom casting, which could improve the as-cast quality effectively. A segment-based three-dimensional mathematic model coupling the electromagnetic field, melt flow, heat transfer and solidification in the whole casting domain is established to study the effect of M-EMS and F-EMS on steel flow and solidification behavior of a bloom casting. The model is validated by the measured data of magnetic flux density in the stirrer center and the white band width for plant tests. According to the simulation and experimental results, M-EMS can introduce a horizontal swirling flow ahead of the solidification front, which changes the flow pattern of melt and promotes the superheat dissipation of molten steel in the mold, and promotes the equiaxed crystals ratio when entering the solidification end stirring zone. M-EMS can make the carter end advanced by 0.347 m, the liquidus cavity width of the final stirring zone and washing velocity of molten steel to the solidification front are reduced. Carbon segregation detection shows that although M-EMS causes subsurface negative segregation and positive segregation of CET transition zone, the significant improvement of center segregation causes the range of carbon content decrease from 0.035% to 0.029%, which promote the homogenization production of bloom casting. It suggests that the reasonable combined application of M-EMS and F-EMS can improve the homogeneity of as-cast macrostructure of special steel blooms, thereby improving heat treatment and service performance of rolled products.

Key words: bloom casting, combined electromagnetic stirring, carbon segregation, white band, crater end

CLC Number:

TF777

WANG Pu, LI Shaoxiang, ZHANG Zhuang, TIE Zhanpeng, DONG Yannan, ZHANG Wei, ZHANG Jiaquan. Effect of Combined Stirring Modes on the Solidification Behavior of Special Steel Bloom Casting[J]. Journal of Mechanical Engineering, 2020, 56(12): 99-106.

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