Abstract

In the continuous casting of steel, the submerged entry nozzle is used to prevent reoxidation by air during the pouring of the molten steel supplied from the tundish to the mold. The submerged entry nozzle, therefore, plays a very important role in assuring high product quality.

However, clogging of the submerged entry nozzle often occurring in the continuous casting of ultra low carbon steel, causes degrading product quality, and also can be leaded to stop the casting process. So, many researchers have been trying to develop the nozzle to suppress clogging. But, evaluation of the nozzle performance was difficult, because nozzle clogging is complexly affected by operation condition of steelmaking and continuous casting process.

In this paper, a new test method with the nozzle that has two different materials of inner section was used to consider performance of the nozzle only.

The testing nozzle that has conventional material(more than 20wt% carbon) and low carbon material(less than 5wt% carbon) of Al2O3, SiO2, C was used in field test. After casting, in order to evaluate performance of the nozzle material, measurements of the clogging thickness of two different materials were carried out. According to test results, Hyundai Steel Company was able to improve clogging by optimizing the nozzle material.