A numerical simulation of a two-roll continuous casting machine has been performed. The influence of the key process parameters on the position of the end of solidification (called here solidification welding point: SWP), and on the stress state in the solidified strip have been analyzed. The stress and strain distribution in the rolling stage and the mechanism of the change of thermal stresses caused by air cooling on the edge crack were analyzed by the structural simulation in the plastic forming stage. The results show that the cracking tendency is the smallest when the cast-rolling temperature is 930 K, the heat transfer capacity of the roll is 3000 W/(m² K) and the cast-rolling speed is 3.2 m/min. The equivalent strain at the edge of the cast-rolled sheet is higher than that in the middle, and cracks are more likely to occur. After passing through the roll gap, the thermal stress changes through three stages: transient, transition and stability, and the shrinkage along the width direction is much larger than that in the thickness direction.

To reveal the influence of pulsed current density on the microstructural evolution and mechanical properties of Mg-Gd-Y-Zn-Zr rare-earth magnesium alloy wires, extruded Mg-10Gd-3.4Y-1.3Zn-0.4Zr alloy wire was selected as the research material. By regulating the current density in the range of 12–20 A/mm², the effects on temperature rise behavior, microstructural evolution, and mechanical properties were systematically investigated. The results show that as the current density increases from 12 A/mm² to 20 A/mm², the measured surface peak temperature rises from 207 °C to 497 °C, and the mechanical properties among the electropulsing-treated samples exhibit a trend of first increasing and then decreasing. Among these treated samples, the optimal combination of strength and ductility is achieved at a current density of 15 A/mm², at which the tensile strength and elongation reach 312.2 MPa and 13.6%, respectively. Microstructural analysis indicates that appropriate pulsed electrical parameters promote the dissolution, fragmentation, and homogenized dispersion of block-shaped long-period stacking ordered (LPSO) phases, thereby optimizing the internal strain state and facilitating the activation of non-basal slip. However, when the current density increases to 20 A/mm², excessive thermal input leads to grain coarsening and a network-like W-phase precipitation, indicating that excessive energy input can lead to microstructural instability and mechanical degradation.

Aiming to solve the persistent problem of edge cracking in magnesium alloy cast-rolling, this numerical simulation study introduces an innovative magnetic field-assisted approach. Utilizing Lorentz force, the process dynamically transforms the solidification front morphology from an arc-shaped (“Ɔ”) to a linear (“1”) configuration. Simulation results reveal that, while magnetic field-induced thermal effects minimally impact the solidification front, the Lorentz force fundamentally alters the flow field dynamics. This modification yields a more uniform temperature distribution and reduces velocity gradients between the symmetric center and edge regions, thereby promoting the transition to a linear solidification front essential for synchronous solidification and deformation across the entire plate width. Furthermore, variations in magnetic field intensity and frequency critically influence vortex flow position and density within the cast-rolling zone. The optimization goal was to maximize the angle α between the side surface and solidification front, which characterizes the linearity of the front. With optimized parameters of 0.49 T magnetic field intensity and 8 Hz frequency, angle α reaches 65°. This marks a 62.5% increase compared to the conventional (non-magnetic) cast-rolling scenario and achieves a near-linear (“1”) solidification profile.