Effect of Cooling Intensity and Position on Solidification in Semi-Continuous Casting of Copper

Abstract

Cooling heat flux effect in both primary and secondary cooling zone has been studied in semi-continuous casting of copper billet. Sufficient cooling is essential to reduce casting defects and to get high productivity, however low rate of solidification is aimed in order to get coarser grain size and softer metal for less losses in extrusion. A three-dimensional numerical model has been developed including solidification behavior of copper through mushy zone. At steady state and constant casting speed, solid shell thickness is monitored during the reduction of cooling rate at mould region to avoid breaking out. Heat flux intensity at mould plays important role not only in the formation of solid shell thickness. But, pool length and mushy zone thickness can be significantly increased by decreasing primary cooling intensity. Increase intensity of secondary cooling zone for two particular cases of primary cooling is tested. First case is tested at mould inlet water temperature of 38˚C, and second case at water temperature of 63˚C. Results showed that the combination of increasing secondary cooling intensity and reduction of primary cooling intensity can increase pool length and mushy zone thickness. Also, it is shown that, secondary cooling intensity can be magnified by up to 1.5 times for cooling water temperature of 63˚C to get pool length close to that of water temperature of 38˚C.

Hydraulic and numerical simulation of flow field characteristics in induction heating continuous casting tundish

“…Considering that the actual temperature difference between the front and back of channel-type tundish is about 8∼12°C . [26][27][28] It can be calculated from Equation (6) that the temperature difference between the two sides of the heating channel in the tundish hydraulic simulation is about 2.5∼3.7°C. In the process of hydraulic simulation experiment, through comparison, when a 3 KW heating rod is placed in the channel and the flow field is stable, the measured temperature difference between the front and back of the channel is between 2.8 and 3.6°C, which meets the Zb criterion requirement.…”

“…It inevitably produces a large temperature drop, which produces a large temperature difference in the tundish and has a greater impact on the quality of the steel billet. 5,6 In addition, there may be large differences in the melt temperature of the ladle due to different heating methods or ladle pouring time in the continuous casting process. Thus, the uncertainty of the inlet flow temperature is also a major obstacle to the realisation of low superheat constant temperature casting in the tundish.…”

Transient heat transfer and solidification modelling in direct-chill casting using a generalized finite differences method

“…The numerical modelling and simulation of physical phenomena involved in continuous casting (CC) and DCC processes are usually based on classical mesh -based approaches [5]. For example, several numerical algorithms based on Finite Element Method (FEM) have been developed for the modelling of three-dimensional fluid flow, heat transfer, and solidification in CC processes [6], the analysis of convective heat transfer in the molten metal and phase change in aluminum DCC [7], prediction of stresses, strains, mushy zone length, and heat transfer in DCC [8], the study of cooling and solidification of semi-continuous casting processes of copper [9], determination of two-fluid flow and the meniscus interface movement in an electromagnetic CC of steel [10], heat transfer study in the primary cooling zone in DCC using experimental measurements of the ingot, mould, and cooling water temperatures during casting [11], the simulation of mould cavity filling process, study of the influence of J. Min. Metall.…”