Numerical and Experimental Study on Carbon Segregation in Shaped Billet of Medium Carbon Steel with Combined Electromagnetic Stirring

Abstract

Carbon segregation is the major and classical internal defect in the continuous casting process of carbon steel. Based on the combined electromagnetic stirring equipment for new billet in a steel plant, China, the influence of combined electromagnetic stirring (M-EMS + F-EMS) on the carbon segregation of 300 mm × 340 mm special-shaped billet was studied via numerical simulation and on-site industrialization tests. The Lorentz force and carbon solute distribution were simulated under different EMS parameters. The formation mechanism of the carbon segregation of medium carbon steel with different combined electromagnetic stirring processes was analyzed. The results show that: (1) with the combined action of “solute flushing” effect and gravity, the carbon concentration in the loose side of the medium carbon steel casting billet is gradually lower than the fixed side, while the carbon concentration on the fixed side gradually accumulates more; and (2) under the action of combined electromagnetic stirring, the segregation index of casting billet could be controlled to remain between 0.96–1.05 and shows an increasing change in solidification from the skin to the center. When the current and frequency of M-EMS are 250 A and 2.0 Hz and the F-EMS are 180 A and 8.0 Hz, the carbon segregation defects in the special-shaped (300 mm × 340 mm) casting billet can be significantly improved.

Effect of Alloying and Microalloying Elements on Carbides of High-Speed Steel: An Overview

“…Optimizing the electroslag casting process to improve the carbide's shape and size and refine the solidified microstructure will be essential to enhance this technology. The physical field represented by electromagnetic stirring and pulse magneto-oscillation has made remarkable achievements in improving the quality of metallurgical billets [103][104][105][106][107][108][109][110][111]. These technologies, especially pulse magneto-oscillation solidification homogenization technology, show greater advantages in low-cost, large-scale, high-speed steel metallurgical manufacturing.…”

The Angular Velocity as a Function of the Radius in Molten Ga75In25 Alloy Stirred Using a Rotation Magnetic Field

“…The aim of simulating the solidification of alloys (like the semicontinuous casting of aluminium alloys or the continuous casting of steels) is to produce a tool that can integrate the planning of the process parameters, which can guarantee a suitable microstructure and good mechanical properties [1][2][3][4][5]. In the continuous casting of steel, magnetic stirring is used worldwide to obtain a microstructure without a columnar zone and central macrosegregation extending across the centre equiaxed zone, refine the grain size, minimise the shrinkage porosity and macrosegregation, and improve the surface quality [6][7][8][9][10][11][12][13][14][15][16][17][18]. The magnetic induction causes a melt flow, and its simulation is complicated and needs correct data, like the ω(B, r) function.…”