Use of Cold Liquid Metal Models for Investigations of the Fluid Flow in the Continuous Casting Process

Abstract

The measurement of flow quantities in a real steal caster is still a huge challenging task. Up to now, only some rough velocity information was obtained from casting plants with liquid steel. More insight into the casting process can be achieved by model experiments, which operate with low melting point liquid metals. The advantage of such cold metal laboratory experiments consists in the capability to obtain quantitative flow measurements with a reasonable spatial and temporal resolution. They are therefore an important tool to investigate the flow structure and related transport processes in melt flows relevant for metallurgical applications. We present two experimental facilities for modeling the continuous casting process of steel. The parameters and dimensions of the facilities will be given. LIMMCAST, the bigger setup, is using the alloy SnBi and works at temperatures of 200-4008C. Possibilities for flow investigations in tundish, submerged entry nozzle, and mould will be discussed. Next, the smaller set-up Mini-LIMMCAST will be presented. This experimental setup works with the alloy GaInSn, which is already liquid at room temperature. During the last decade, new measurement techniques have been established for detecting the velocities in liquid metal flows and which are operating in the considered temperature ranges. By this, it is now possible to do experimental investigations for a satisfying characterization of flow quantities in the two models. A selection of results from both experimental setups will be shown. These flow measurements deliver a valuable experimental database being suitable for validation of numerical simulations.

Effect of Single-Ruler Electromagnetic Braking (EMBr) Location on Transient Flow in Continuous Casting

“…The position z ¼ 0 corresponds to the lower end of the nozzle. More details about the three-dimensional measurements of the magnetic field distribution can be found in Timmel et al [11,18]. The single-ruler-shaped magnetic field has a major field component, which is parallel to the narrow mold face in Y-direction.…”

“…The spacing between the transducers is 10 mm, resulting in a total height of the measuring field of 90 mm, as shown in Figure 1(d). A more detailed description of the measurement method and procedure is given elsewhere [18].…”

“…Electrically conducting walls allow for a closure of the induced currents outside the liquid region [14], which has a dramatic effect on the Lorentz force distributions [13], and a stabilizing effect on the flow [11][12][13][14][15]. Recently, mold flow in a scaled physical model with GaInSn, a low melting liquid metal alloy, has been studied with ultrasonic Doppler velocimetry (UDV) measurements [11,18] and large eddy simulations (LESs) [12][13][14] to investigate the effect of ruler electromagnetic braking (EMBr) on transient flow phenomena, with conducting (brass) versus insulated (plastic) side walls. The application of a single-ruler EMBr over the nozzle with insulated walls made the mold flow unstable, with large-scale wobbling of the jets.…”

Effect of Electromagnetic Brake on Transient Asymmetric Flow, Solidification, and Inclusion Transport in a Slab Continuous Casting

“…Subsequently, a 1/5-scaled physical model using low-melting liquid metal mercury was developed to validate the fluid field based on similarity principle, the Froude number for physical model was equal to the prototype, and the details can refer in previous work. [33] During this process, the transient velocity inside the physical model was measured by means of the Ultrasound Doppler Velocimetry (UDV), [34,35] in order to measure the horizonal velocity and vertical velocity, five sensors with a distance of 30 mm for each sensor were installed at the mold narrow wall and eight sensors with a distance of 15 mm for each sensor were installed at the free surface, respectively. Finally, the time-averaged horizontal velocity and vertical velocity were interpolated to obtain 2D contour plot.…”

Modeling Asymmetric Flow in the Thin‐Slab Casting Mold Under Electromagnetic Brake

“…[11] The asymmetric flow in the mold was investigated experimentally in early 1990 s by Gupta and Lahiri and later on supplemented by the consequent works of other researchers. [12][13][14][15][16][17][18][19] The interaction of the fresh hot melt turbulent flow with the solidifying solid shell is generally an important topic in the solidification process. It becomes especially crucial in continuous casting.…”