1. Introduction

In continuous casting of steel, controlling the transfer of molten steel from the tundish to the mold is one of the most critical tasks for ensuring product quality, process stability, and operational safety. Among the refractory flow-control and protection devices used in this zone, the Sub Entry Shroud (SES) plays a decisive role. The sub entry shroud is not merely a mechanical connection between the tundish nozzle and the mold; it is a key metallurgical component that protects molten steel from reoxidation, stabilizes flow, and directly influences inclusion behavior and surface quality of the cast strand.

1. Introduction

In modern steelmaking, continuous casting has become the dominant technology for transforming molten steel into semi-finished products such as slabs, blooms, and billets. Within this process, the tundish plays a critical role as an intermediate vessel between the ladle and the mold. Beyond its function as a distributor of liquid steel, the tundish is also a metallurgical reactor where temperature control, inclusion flotation, and flow optimization occur. One of the most important flow-control devices installed in the tundish is the tundish stopper rod.

1. Bevezetés

A Sub-Entry Shroud (SES) – más néven acélbevezető védőcső – kulcsfontosságú tűzálló elem a folyamatos acélöntési technológiában. Ez a cső köti össze az acélüst kifolyó fúvókáját a közbenső üst (tundish) bemeneti rendszerével, illetve egyes konfigurációkban a merülő belépő fúvókával (SEN).

A SES elsődleges feladata az, hogy megvédje az olvadt acélt a levegővel való érintkezéstől, megakadályozza a másodlagos oxidációt, csökkentse a nitrogénfelvételt, valamint stabilizálja a fémáramlást.