Effect of chilling of the top part of a steel ingot on the conditions of its crystallization and the quality of forgings obtained from it

Galkin, A. N.; Zyuban, N. A.; Rutskii, D. V.; Gamanyuk, S. B.; Puzikov, A. Ya.; Firsenko, V. V.

doi:10.1007/s11015-013-9713-1

Cited by 6 publications

(5 citation statements)

References 1 publication

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“…The pioneering work of Flemings et al, developed in the 1960s [4,5], set the theoretical bases for studying the mechanisms of macrosegregation. Since then, intensive research has been underway, and some critical process parameters have been identified and used as 'countermeasures' to produce sound ingots with improved quality and limited macrosegregation [6][7][8][9]. Specially, stringent control of the superheat [7], accelerating the solidification process in the mold [8], and improving ingot dimensions and configurations [9] have been investigated experimentally and numerically by researchers.…”

Section: Introductionmentioning

confidence: 99%

On the Effect of Filling Rate on Positive Macrosegregation Patterns in Large Size Cast Steel Ingots

et al. 2018

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The effect of filling velocity on positive macrosegregation in large size steel ingots was studied. Macrosegregation and macro/microstructures were characterized on the hot-tops and a portion of the upper section of two ingots. The measurements revealed that segregation features in the two ingots varied as a function of the alloying elements, and that the severity of positive macrosegregation in the casting body was reduced when the filling rate was increased. It was also found that at the higher filling rate, grain morphologies in the first solidified zones of the ingot changed from columnar to equiaxe, and secondary dendrite arm spacing (SDAS) became slightly smaller in the intermediate and final solidified zones. The experimental findings were analyzed in the framework of diffusion and convection-controlled solidification, as well as liquid metal flow theories. The solute dependence of segregation features was related to the difference in the solid-liquid partition coefficient and diffusion capability of each element in the liquid iron. Calculation of Reynolds numbers (Re) during the filling process, for both ingots, showed that higher filling velocity caused more instable movement of the liquid metal in the initial solidification stage, resulting in the modification of grain morphology, as well as accelerated solidification rate.

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Section: Introductionmentioning

confidence: 99%

On the Effect of Filling Rate on Positive Macrosegregation Patterns in Large Size Cast Steel Ingots

et al. 2018

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“…The entrainment of the air and mold powders during the initial filling process is of significance to the cleanliness and the quality of the ingot product. [2,3] Investigations have been performed to improve and control the flow pattern during the ingot filling process, [4][5][6][7][8] and extensive studies have been done on the heat transfer, [9,10] shrinkage cavity, [11][12][13] crack, [14,15] stress-strain, [16][17][18] segregation, [19][20][21] and the generation and removal of inclusions [3,22] during the cooling and solidification process of the steel ingot. Zhang et al [23] studied the influence of argon hood protection devices on air absorption and reoxidation during filling.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation on the Fluid Flow, Air Entrainment, Heat Transfer, and Solidification during Top Pouring and Cooling of a 303 Ton Heavy Ingot

Wei

Zhou

Chen

et al. 2023

steel research int.

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Herein, a mathematical model combined with the k–ε turbulence model, volume of fluid multiphase model, and heat transfer and solidification model is established to investigate the steel–air two‐phase flow and solidification during the filling process of a 303 ton heavy steel ingot. The measured temperatures at different times are employed to validate the current mathematical model. The results show that the predicted results are in good agreement with the measured results. At the initial stage of the filling process, a double‐roll flow pattern is formed near the junction between the liquid surfaces due to the high speed of the jet flow. The maximum impinging depth of the jet flow is 1.8 m and the maximum splash height of the molten steel is 0.3 m. An empirical formula for the variation of the entrained air volume with time is proposed. The maximum growth rate in the horizontal direction is 0.08 mm s−1. In the vertical direction, the maximum growth rate of the solidified shell on the central axis is 0.12 mm s−1. The distribution of primary dendrite arm spacing and secondary dendrite arm spacing is obtained by combining the predicted cooling rate.

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“…In order to achieve high quality large-size cast ingots, a better understanding of the influence of chemical composition and process parameters is needed in order to be able to take measures for minimizing the extent and intensity of macrosegregation. The measures commonly taken include control of chemical compositions (reduction of Mn and Si contents) [5], improvement in mold geometry [6,7], optimisation of casting process (control of melt temperature, mold preheating temperature, filling rate) [8,9], employment of engineering solution (intensive rapid cooling, mechanical vibration and electromagnetic stirring) [10,11], and application of multipouring technique (sequential pouring of molten steel from multiple ladles with different concentrations of alloying elements) [12]. Among the above strategies, superheat control is one of the simplest methods to implement.…”

Section: Introductionmentioning

confidence: 99%

Simulation and experimental validation of the effect of superheat on macrosegregation in large-size steel ingots

Zhang

Jahazi

Tremblay

2020

Int J Adv Manuf Technol

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A 3D model was employed to study the effect of melt initial superheat on the macrosegregation formation using FE modeling and experimentation methods. The casting process of three ingots with the initial melt superheats of 75°C, 65°C and 55°C were simulated. The three cases represented three variables encountered in industry during casting of large size ingots. For the above three studied cases, all other casting conditions were kept the same. Results showed that the variation of initial melt superheat gave rise to changes in temperature pattern, liquid flow field, solidification speed, and thermomechanical contraction. Under the combined actions of all these changes, lower superheat tended to alleviate the segregation intensity in the upper part of the ingot body, in the hot-top, and in the solute-rich bands between the ingot centerline and periphery. The beneficial effect of lower superheat on alleviation of segregation severity was confirmed by experimental chemical measurement results. The results were analyzed in terms of heat and mass transfer theories and allow for a better understanding of the underlying mechanisms responsible for the occurrence of macrosegregation in ingot casting process. The findings should be helpful for the casting process design of a given ingot of high value-added steels or other alloys.

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Effect of chilling of the top part of a steel ingot on the conditions of its crystallization and the quality of forgings obtained from it

Cited by 6 publications

References 1 publication

On the Effect of Filling Rate on Positive Macrosegregation Patterns in Large Size Cast Steel Ingots

On the Effect of Filling Rate on Positive Macrosegregation Patterns in Large Size Cast Steel Ingots

Numerical Simulation on the Fluid Flow, Air Entrainment, Heat Transfer, and Solidification during Top Pouring and Cooling of a 303 Ton Heavy Ingot

Simulation and experimental validation of the effect of superheat on macrosegregation in large-size steel ingots

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