This paper presents optimum operating parameters for the production of thin strips of 40 mm in width and ∼4 mm in thickness of Fe-17%Mn-4%Al-3%Si-0.45%C wt-% TWIP (TWinning Induced Plasticity) steel using the present version of the Horizontal Single Belt Casting (HSBC) process. A two-dimensional model was developed to examine the flow of molten metal in the HSBC process, primarily focusing on investigating the instabilities/turbulence that arises when molten metal encounters the moving belt. For computational fluid dynamics modelling, three belt speeds were tested, i.e. 0.4, 0.8 and 1.2 (m s −1 ), against a constant molten metal velocity of 0.8 m s −1 at the nozzle slot outlet. It was observed that the molten metal/air interface fluctuations were appreciably suppressed/reduced when the belt and molten metal velocities approached each other. The fluctuations formed are damped further downstream, and any remaining surface perturbations can be eliminated via hot plastic deformation. An appropriate heat treatment was also designed for the TWIP steel strips, in order to achieve the desired microstructure and mechanical properties.

In this research study, numerical modelling and experimental casting of AA6111 strips, 250 mm wide, 6 mm thick, was conducted. The velocity of the molten AA6111 alloy at the nozzle slot outlet was raised to 2 m/s, whilst the belt speed was kept at 0.3 m/s. The numerical model demonstrates considerable turbulence/fluctuations in the flow of the molten AA6111 alloy in the HSBC process, rendering its free surface highly non-uniform and uneven. These discontinuites in the flow resulted from the sudden impact of molten metal onto the inclined refractory plane, and then onto the slowly moving belt. However, it has been determined that these surface variations are rapidly damped, and as such are not detrimental to final strip surface quality. Any surface perturbations remaining can be eliminated via hot plastic deformation. The experimental findings are in accordance with the model predictions. Furthermore, at high metal heads inside the delivery launder, the molten metal was observed to be flowing inwards towards the center of the strip, thereby filling the centre depression region, formed otherwise. The model predictions were validated against experimental findings. A surface roughness and microstructural analysis was also conducted to determine the surface and bulk quality of the as-cast strip.

This research presents numerical modeling and experimental results on thin strips of Fe–21%Mn–2.5%Al–2.8%Si–0.08%C wt% steel, obtained using the horizontal single belt casting (HSBC) process. The free stream of the molten metal, exiting from a nozzle slot, was observed to be highly unstable and nonuniform, after interacting with a 30° inclined refractory plane of a delivery system. However, increasing the inclination of the refractory plane to 45°–60° allows the falling molten metal free stream to become much more stable and less fluctuating. In addition, the molten metal can undergo a hydraulic jump when impacting and flowing down these inclined refractory planes. These hydraulic jumps result in the generation of free surface waves, which travel further downstream. Fortunately, these instabilities are not usually detrimental to the surface quality of the casting, as they are rapidly damped, to disappear within a short distance, prior to solidification. The types and numbers of solid phases then forming for this steel, under the relevant Scheil cooling conditions, are determined using FactSage software. The surface roughness of the cast strip was evaluated using a Nanovea 3D surface profilometer. Microstructures of the cast and heat‐treated strips were determined using Optical and Electron microscopes.

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