Revisiting dynamics and models of microsegregation during polycrystalline solidification of binary alloy

Gong, Tongzhao; Chen, Yun; Li, Shanshan; Cao, Yingnan; Li, Dianzhong; Chen, Xing-Qiu; Reinhart, Gunther; Nguyen-Thi, Henri

doi:10.1016/j.jmst.2020.09.038

Cited by 16 publications

(11 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Figure 12 shows variations in the solute segregation index, S I , and solid fraction of the samples along the mold in the 45°, 135°, 225°, and 315° domains. The formula of the solute segregation index, S I , can be described by [ 7 ]

S_{normalI} = \frac{1}{V} \int_{V}^{} \frac{false| C_{i} - C_{0} false|}{C_{0}}

where C i is the solute concentration at the i th cell and V is the total domain volume. S I is appropriate to evaluate the spatial deviation of the solute concentration from C 0 .…”

Section: Resultsmentioning

confidence: 99%

“…The second and third terms on the right-hand side of Equation ( 6) are the effect of constitutional undercooling and curvature undercooling on the interface equilibrium concentration, respectively. [31] In Equation ( 6), C0 is the initial solute concentration, T l is the liquidus temperature at C 0 , m l is the slope of liquidus, Γ is the Gibbs-Thomson coefficient, and K is the local mean interface curvature, which can be described by Equation (7).…”

Section: Dendritic Evolution Modelmentioning

confidence: 99%

“…Figure 12 shows variations in the solute segregation index, S I , and solid fraction of the samples along the mold in the 45 , 135 , 225 , and 315 domains. The formula of the solute segregation index, S I , can be described by [7]…”

Section: Effect Of Local Mold/billet Heat Fluxes On Microsegragationmentioning

confidence: 99%

“…The main factors affecting microsegregation are the equilibrium distribution coefficient k 0 , diffusion coefficient D, cooling rate, etc. Extensive experimental studies, [1][2][3][4] theoretical analysis, [5,6] and numerical calculation [7][8][9] have focused on microsegregation during the solidification of alloys. Microsegregation models, such as the lever rule and Scheil equation, hold true for the solidification process with different simplifications and assumptions.…”

Section: Introductionmentioning

confidence: 99%

“…[10] With the development of the phase field (PF) method [11,12] and cellular automaton (CA) method, [13][14][15][16][17][18][19] the prediction of microstructure and quantitative analysis of microsegregation has become an important research tool in recent years. [7,8,10,20,21] Luo et al established a CA-finite difference (CA-FD) model for the simulation of solute diffusion-controlled solidification in continuous casting, and columnar growth and columnar to equiaxed transition were produced. [22] Wang et al established a CA-finite volume method model considering macroscopic heat transfer and microscopic dendritic evolution; grain structure in a selected region near the billet centerline of the steel grade for SWRH82B was simulated; and they studied the influence of secondary cooling intensity, casting speed, and superheating on the grain structure of the billet.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Modeling of the Nonuniform Microstructure and Microsegregation Formation of the Shell in Round Billet Continuous Casting

Wei

Wang

Liu

et al. 2022

steel research int.

View full text Add to dashboard Cite

To explore the influence of nonuniform heat transfer on the grain structure and microsegregation of carbon in shells inside the mold, a multiscale model considering heat conduction and dendritic growth is constructed for the round billet continuous casting. Adopting measured heat flux as the boundary conditions, heat conduction in the mold is solved by the finite difference scheme, and dendritic growth is modeled by the cellular automaton model. The temperature distribution of the round billet under measured heat flux is calculated, and the grain structure and the microsegregation of carbon in four selected regions are simulated. Herein, it is shown in the results that the different local heat fluxes lead to dissimilar variations in the surface temperature and grain structure of the shell. A close relationship exists between the carbon microsegregation and local heat flux; the carbon microsegregation decreases with heat flux. The high heat flux accelerates columnar dendritic growth and fines the columnar dendritic array so that the secondary arms are less developed and the microsegregation is improved.

show abstract

S_{normalI} = \frac{1}{V} \int_{V}^{} \frac{false| C_{i} - C_{0} false|}{C_{0}}

where C i is the solute concentration at the i th cell and V is the total domain volume. S I is appropriate to evaluate the spatial deviation of the solute concentration from C 0 .…”