Estado da arte na redução de obstruções de válvulas submersas em lingotamento contínuo de aços

To obtain high-quality steel, the variables in the process must be controlled and optimized to mitigate flaws. An important variable in the steel solidification process in steelmaking during continuous casting machine operation was studied in this work, the control of the liquid metal flow from the tundish to the mold, highlighting the crucial function of submerged entry nozzle. This study was conducted through a comprehensive literature review. The poor performance of the submerged entry nozzle, especially with obstruction, impacts the quality of steel and hinders productivity by affecting the sequencing of heats in the steelmaking. It is a common flaw in many continuous casting machines although the studies on phenomena affecting this refractory component are not yet fully understood, several factors are associated with failures. Practical recommendations have been formulated with the main techniques to reduce blockages, among which the modification of the submerged nozzle geometry stands out, aiming to increase the effective area and achieve a uniform velocity profile. Additionally, efficient argon injection plays a crucial role in minimizing non-metallic inclusions and improving steel flow.