To investigate the effect of soft reduction on the centre macrosegregation during the continuous casting process, a mathematical model coupling flow, solidification and species transfer was developed. Moreover, a soft reduction model had been incorporated into the coupling model. The solidification model was validated by methods of the billet surface temperature measurement and the tracer experiment. The predicted results revealed that the carbon enrichment occurred at the solidification front during the solidification process of the molten steel. The centre segregation ratio was 1.2 in the billet centre without soft reduction. The calculation results and experimental results showed that the centre segregation ratio at the centre solidification fraction of 0.3 with soft reduction was 1.11 and 1.09, respectively. The experimental results with the soft reduction at the centre solidification fraction of 0.3 had a good agreement with the calculation results.

His academic background and research activities have been focused on ferrous metallurgy, in particular application of thermodynamics and kinetics of gas-solid reactions, kinetics of steel refining in the ladle furnace, physical modeling of bottom stirring in metallurgical ladles, slag foaming in the EAF, mathematical modeling of DRI melting in the EAF, etc.

A two-dimensional axisymmetric steady-state arc model and a three-dimensional current density distribution model are established in this study, and the effects of electrode embedded with magnesia-carbon material on electrode current density distribution and DC arc characteristics are studied. The results show that when the electrode embedded with magnesia-carbon material is used, the magnesia-carbon material in the electrode is not conductive, and the maximum current density (excluding cathode spots) increases with the increase of the radius of the magnesia-carbon material. Moreover, with the increase of the radius of magnesia-carbon materials, the maximum temperature and maximum axial velocity in the center of the arc, the maximum value of shear force, heat flux and pressure of arc on anode center are reduced, the position of the maximum temperature and the position of the maximum axial velocity migrate from near the cathode to the anode. The other temperature ranges first increase and then decrease in the radial direction, the shear force, heat flux, and pressure of arc on area within a certain distance from the center increases. Therefore, the appropriate radius of magnesia-carbon material can improve the heat transfer conditions and dynamic conditions of the arc on the area near the molten pool center.

The breakdown plays an important role in the process of arc striking, which can form an early conductive channel between electrode and molten pool. In this paper, a two-dimensional transient micro-gap breakdown model of argon gas under atmospheric pressure and a two-dimensional calculation model of electric field in arc were established, and the effect of the electrode embedded with magnesia-carbon material on the breakdown process and electric field in arc are studied. It is found that the breakdown process between the electrode and the molten pool develops in the form of positive streamer, whether using ordinary electrode or electrode embedded with magnesia-carbon material. The electrode embedded with magnesia-carbon material can accelerate the development of head of electron avalanche in the process of breakdown in micro-gap, increase the electron density of head of electron avalanche and shorten the time consumed in the process of breakdown. Under the external voltage in AC arc, the maximum value of electric field strength changes periodically, the region of the maximum value and maximum value increases with the increase of the radius of the magnesia-carbon material, resulting in serious distortion in the distribution of electric field, which can effectively reduce the breakdown voltage threshold.

Under the dual requirements of cost reduction and double carbon goal, it is more meaningful to reduce the continuous consumption of graphite electrode in ladle furnace. In this paper, the three-dimensional coupling model of electromagnetic field, heat transfer, flow field is established, and the influence of embedded steel rod on the current, temperature and continuous consumption of graphite in the electrode was studied. The current in graphite and steel rod is mainly distributed in the edge area near the left electrode, respectively. With the increase of the radius of the steel rod, the proportion of the current passing through the steel rod to the total current increases, the area of each temperature range above 500 K and the total continuous consumption rate of the electrode decrease.