In order to avoid nozzle clogging, argon gas was blown into submerged nozzle from stopper during slab continuous casting process, some inclusions attached on the bubbles can remove by bubble floatation during the continuous casting process. But the bubbles also affect the flow pattern, and may become entrapped to form defects in the final products. Defects due to bubble and non-metallic inclusions are very harmful to the quality of steel sheet, especially ultra low carbon steel. Argon gas can alleviate some problems, such as meniscus freezing and vortex formation, but can aggravate other entrainment mechanisms, such as the top surface fluctuations. Additionally, nonmetallic inclusions and slag can adhere to the surface of argon bubbles, leading to large defects if entrapped in the final products.
Authors: Wang Kun, Luo Yanzhao, and Zhen Xingang
Keywords: bubble, mold powder, inclusions, clogging