The prefabricated components are made primarily from magnesia-based refractory aggregates and fine powders, combined with micro- and ultrafine powders, prefabricated into shape, and then treated by medium-temperature baking. This product can be used to improve the flow pattern of molten steel in the tundish under the kinetic energy of the ladle steel stream, facilitate the floating of inclusions, and enhance the quality of continuous casting billets.