Investigation on Ladle Nozzle Clogging during Steel Pouring Process

摘要

Nozzle clogging during steel pouring and continuous casting process is a long-standing problem for Al-killed steels. The pouring flow rate through the nozzle often decreases due to nozzle clogging, which then can lead to serious operational problems. For example the metal flow is decreased and even entirely eliminated at sometimes. The clogging of the submerged entry nozzle from tundish to mold has been well studied. However, there is little research reported for the clogging of the shroud nozzle from ladle to tundish during steel pouring process. With serious clogging of ladle nozzle, even though the slide gate at the bottom of the ladle is fully open, the flow rate of the molten steel can hardly meet the demand of tundish, especially after pouring for some time, then the fluid level in tundish drops and the casting speed has to be decreased. During the continuous casting of Q235B steel at Qian'an steelmaking plant (Capitcal Steel Group, China), the clogging of ladle nozzle was observed The current paper is to investigate the causes of this clogging issue and investigate counter measures.