Metallurgical Effects of a Novel Tundish Refining Process for High-Strength Low-Alloy Hot-Rolled Plate Steels

Resumo

A novel tundish refining technology has been developed for the production of complex alloying corrosionresistant steel plates made from continuously cast slabs. This technology includes application of filtering elements installed in the tundish buffers to provide a decrease in the nonmetallic inclusion content in the slab body. It also makes use of injection-vertical shrouding of the steel in the area of steel ladle-tundish for the reduction of oxygen and nitrogen content in the steel and for the reduction of aluminum consumption. Argon rinsing of liquid steel in the tundish through ceramic bottom lances with a modern design is proposed for the removal of fi ne inclusions (≤20 μm). There was an overall decrease of the tested steel contamination by 2.0–2.5 times, and the amount of sulfide inclusions decreased, on an average, by 65%, oxide inclusions by 40%, and nitride inclusions by 60%. Hydrogen removal reached up to 0.3–0.8 ppm. Comprehensive metallographic examinations confirmed the efficiency of the novel tundish refining process and the high yield of high-performance rolled plates.