Investigations of the solidification structure of continuously cast slabs

Abstract

A study of solidification phenomena performed under industrial conditions is presented. The solidification structure of high carbon, medium carbon and microalloyed steel grades was observed and correlated to casting parameters such as superheat and secondary cooling. Experimental data of dendrite morphology are related to calculated solidification variables. The calculation is based on the solution of the enthalpy balance equation. An expression for the dependence of secondary dendrite arm spacing on solidification variables is proposed for columnar growth. The results are compared to the findings of other authors. The effect of chemical composition on secondary dendrite arm spacing was observed. Therefore the developed relationships are extended to carbon content on the basis of the presented experimental data.

Mathematical Model for Prediction of Composition of Inclusions Formed during Solidification of Liquid Steel

“…Several correlations and measurements of SDAS are reported in literature. 27,28) Won and Thomas 22) have critically analyzed some of them and proposed the following correlations. The investigators 22) have demonstrated the applicability of their correlations over a wide range of carbon concentration.…”

Simple model of microsegregation during solidification of steels

“…Using SDAS valto approximate the dendrites. Battle and Pehlke [36] developed ues measured by several different researchers [47][48][49][50][51] at various a similar numerical model for plate dendrites and included cooling rates and steel carbon contents, an empirical relationcoarsening of the dendrite arms. The approach of Matsumiya ship was obtained by a best fit as follows: et al has been developed further to consider the ␦/␥ transformation, which occurs during solidification of steels.…”

“…For carbon contents lower than 0.53 wt pct, when the melt cools down slightly below the liquidus temperature, solid nucleates and grows as ␦ phase until solidification is complete (low carbon content) or until the peritectic temperature is reached (middle carbon content). At the peritectic temperature, solid ␥ phase starts to form around the periphery of spacings [47][48][49][50][51] as a function of carbon content at various cooling rates.…”

“…[12] are in reasonable agreement with the previous causes a switch from ␦-phase to ␥-phase solidification once experimentally measured data. [47][48][49][50][51] the carbon concentration exceeds 0.53 wt pct C. This change suddenly lowers the diffusion rates, which increases micro-B. Multicomponent-Alloy Effect segregation and further lowers the solidus temperature.…”

Microstructure and Cleanliness of Rapidly Solidified Steels

“…Several research studies have been carried out with the aim of understanding the SDAS in steels. According to theoretical investigations from the past, the following relationships between SDAS (l 2 ) and solidification parameters have been established [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] The symbols and definitions are listed in Table 1. Material constants a n and exponents b n depend on steel composition.…”