Steel Cleanliness Depends on Inflow Turbulence Intensity (in Tundishes and Molds)

Economically, steel cleanliness is important. Cleaner steel contains fewer inclusions. Inclusions are removed, and thus cleanliness improves when steel is molten. Consequently, simulation of steel flow must be as accurate as possible. Steel flow in tundishes and molds is turbulent. In most turbulent flows, it is assumed that turbulence is generated inside the flow rather than entering with inflow. Due to this assumption, inflow turbulence intensity (\(I_{\text{in}}\)) is sometimes not reported. If \(I_{\text{in}}\) is reported, its values differ greatly among different papers. The present study shows, for the first time, that \(I_{\text{in}}\) must be accurately specified because it affects steel cleanliness. In other words, the inclusions’ interaction (RTD curves), slag turbulence intensity and other factors concerning steel cleanliness depend on \(I_{\text{in}}\). This dependence is proved numerically by applying different \(I_{\text{in}}\)s to steel flows in two industrial tundishes, two industrial molds and water models of a tundish and a mold. In addition to revealing this dependence, the results also disclose interesting facts regarding steel cleanliness. For example, this article illustrates that a tundish’s performance can change with \(I_{\text{in}}\). Therefore, a tundish’s performance depends on the design of the upstream devices as well as its own design.