The Effect of Basicity on the Radiative Heat Transfer and Interfacial Thermal Resistance in Continuous Casting

Heat-Transfer Phenomena Across Mold Flux by Using the Inferred Emitter Technique

“…With the lower interfacial thermal resistance due to the glassy bottom slag/mold interface, the steady-state heat flux of flux 1 at stage VIII is higher than flux 2 and flux 3. The results are consistent with previous studies [6,17,24] that the interfacial thermal resistance is the dominant factor affecting the heat-transfer between the strand and mold.…”

“…From the digital images, it was clearly observed that glassy films of flux 1 and flux 2 are partially crystallized at stage II with the increase of the incident energy, then get further crystallized (stage III) and step into a relatively constant state (stage IV), which is consistent with our previous observations. [24] Then, with the further addition of incident energy, the disk top surface temperature is getting higher and the melting/ crystal dissolution are initiated at the top surface as shown in the picture at stage VI. With longer annealing time, the molten layer moves down and leads to a larger reduction of the crystal volume at stage VII.…”

“…Here, it was assumed that [9,24] (1) heat is transferred in one direction from the mold fluxes to the copper mold; and(2) the total heat flux is consisted of radiative and conductive heat flux. Therefore, the total heat flux q tot through the mold flux film can be expressed as Eq.…”

<i>In-situ</i> Study of Crystallisation Behaviour of CaO–SiO₂–Na₂O–B₂O₃–TiO₂–Al₂O₃–MgO–Li₂O Fluorine-free Mould Fluxes with Different CaO/SiO₂ Ratios

“…The suppression of heat flux can be achieved by applying mould fluxes with high crystallisation tendency and, accordingly, thick crystalline layer [2][3][4][5][6] due to the scattering effect on thermal radiation at the grain boundaries. [7][8][9][10] Heat transfer is also suppressed by the formation of high thermal resistance pores, cracks and air gaps in the wake of the shrinkage of crystalline layer.…”

“…[7][8][9][10] Heat transfer is also suppressed by the formation of high thermal resistance pores, cracks and air gaps in the wake of the shrinkage of crystalline layer. 5,[11][12][13][14] Currently, most of the commercial mould fluxes contain fluorides, like CaF 2 and NaF, to improve lubricity and control heat transfer rate through the formation of cuspidine (Ca 4 Si 2 O 7 F 2 ). [15][16][17][18] However, the high volatility of fluorides at high temperature brings about serious problems such as health hazards to operators, acid rain and corrosion of submerged entry nozzle and secondary cooling system.…”