Numerical modelling and experimental casting of 17%Mn–4%Al–3%Si–0.45%C wt-% TWIP steel via the horizontal single belt casting (HSBC) process

Abstract

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.