Initial Solidification and Its Related Heat Transfer Phenomena in the Continuous Casting Mold

Abstract

The initial solidification of molten steel in the mold is very important, as it is the origin of the final slab, which associates with the surface defects and determines the final quality of casting slab. In this article, six main topics, including the initial solidification study method, molten steel solidification, mold flux structure, fluid flow, oscillation marks formation, and breakout are reviewed with the purpose to explore the intrinsic mechanism of the complex initial solidification process and its related multi-phase heat transfer phenomena. The results summarized here can provide a foundational understanding of the initial solidification and heat transfer phenomena occurring in the continuous casting mold.

A numerical approach for heat flux estimation in thin slabs continuous casting molds using data assimilation

“…Thomas et al 7 studied the steel flow and solidification in the mold including the transport of superheat with the turbulent transient flow of molten steel, surface level fluctuations, and the transport and entrapment of inclusion particles. On the other hand, a detailed description of the solidification in casting is available in the Stefanescu's monograph, 8 while a review on the initial solidification models was done by Wang 9 …”

Prediction Model for Degree of Solid-shell Unevenness during Initial Solidification in the Mold

“…Φ q in the specific carbon region is low due to air gaps that form as a result of peritectic transformation. [18][19][20] However, the solid-shell unevenness may not precisely coincide with Φ q of the mold, 21) because both phenomena are also affected by other factors including casting speed 21,22) superheat, 4,23) mold lubricant, 3,18,24,25) oscillation conditions and moldlevel fluctuation. 3,21,26,27) Some researchers have attempted to quantify the unevenness of solid-shell by measuring the solidification profile of steel according to the carbon concentration ([C]).…”

“…In addition, if the solid-shell is uneven, heat transfer is disturbed by air gaps that form between the solid-shell and the mold wall; this disturbance extends the time for which the initial solid-shell is exposed to high temperature, and thereby promotes coarsening of grains on the surface of the cast steel. [2][3][4][5][6][7][8] These coarse grains cause concentration of segregation and stress at grain boundaries, so surface cracking is facilitated. [9][10][11][12] During continuous casting, peritectic steels in which the solid-shell is unevenly solidified also have relatively large mold level fluctuations, which degrade the surface quality of the cast steel.…”

Characterization and Assessment of Mold Flux for Continuous Casting of Liquid Steel Using an Inverse Mold Simulator

“…To overcome the difficulties in experimenting with the interaction of various casting parameters on the mold flux behavior, inverse mold simulator techniques were introduced. [17][18][19][20][21][22][23][24][25][26][27] Inverse mold simulation is a unique experimental technique, intelligently designed to assess the performance of mold flux in a closely industry simulated environment. Inverse mold simulator study has gained importance due to involvement of dynamic conditions (e.g., liquid steel-flux interactions, mold flux melting, and infiltration; casting speed, oscillation frequency, and stroke; solidifying steel shell; and slag film) prevail during continuous casting operation.…”