Bright-band defects frequently occur on as-cast strips in the twin-roll strip-casting process, particularly at low-casting speeds, with intervals of approximate to 200 mm. Additionally, the cast-rolling force also exhibits minor fluctuations. With increasing casting speeds, the spacing between bright-band defects widens, and the severity of these defects diminishes. When the casting speed reaches a certain threshold, defects almost entirely disappear. Detailed analysis of the underlying causes of this phenomenon is essential for effectively preventing defect formation. In this study, the numerical simulation method is employed to analyze casting rolls' thermal deformation and the melt pool's solidification behavior, based on the production site equipment and process conditions. The causes of defects in as-cast strips are thoroughly analyzed based on simulation results, in conjunction with variations in the cast-rolling force. In this study, it is demonstrated that the thermal deformation of casting rolls and the position of the solidification endpoints collectively contribute to the fluctuations in cast-rolling force and are the primary causes of bright-band defects. Fundamental principles for preventing defects are provided based on actual on-site production. Furthermore, simulation results contribute to establishing a theoretical basis for selecting process parameters and controlling cast-rolling force during production. Bright-band defects in twin-roll strip casting, prominent at low speeds, diminish as casting speeds increase. In this study, numerical simulations are used to explore the thermal deformation of casting rolls and solidification behavior of the melt pool, linking these factors to defect formation. In these findings, strategies for defect prevention and process optimization based on production conditions are suggested.image (c) 2024 WILEY-VCH GmbH
