Effect of a Channel-Type Tundish Filter on Molten Steel Cleanliness and Casting Stability During the Continuous Casting of Ultra-Low-Carbon Steel

Al2O3-based inclusions in Ti-bearing ultra-low-carbon steel readily promote stopper-rod accretion and submerged entry nozzle clogging, thereby impairing molten steel cleanliness and casting stability. This study evaluated the performance of an LGTF11 channel-type tundish filter as an alternative to a conventional weir–dam flow-control system under full-scale industrial conditions. A simultaneous two-strand comparison was conducted during a representative six-heat DR07 slab-casting sequence. Filter performance was assessed by total oxygen and nitrogen analysis, automated ASPEX inclusion statistics, small-sample electrolytic extraction, SEM–EDS, filter-deposit characterisation, stopper-rod monitoring, submerged entry nozzle inspection, and hot-rolled product assessment. The filter reduced the mean total oxygen content from 24.0 to 19.0 ppm, a decrease of 20.8%. The total inclusion number density decreased from 28.3 to 12.9 particles mm−2, while the Al2O3-type inclusion density declined from 9.0 to 5.1 particles mm−2, corresponding to reductions of 54.4% and 43.3%, respectively. Reduced nozzle accretion, more stable stopper-rod and mould-level control, and a decrease in the hot-rolled warping-defect rate from 6.7% to 3.4% were also observed. These findings demonstrate the practical potential of the filter; however, they are derived from one representative industrial case and require validation across additional steel grades, tundish configurations, and operating conditions.