Controlling the rate of cooling during the start-up phase of the Direct-Chill (DC) casting process is challenging and crucial as this region is highly prone to defect formation. During the DC casting process, primary cooling in the mold is followed by secondary cooling in which the partially solidied shell impinges with cooling water from an array of jets. The start-up phase of DC casting is the most critical phase because of its transient nature. This results in varying thermal boundary condition for the same set of parameters. The defect formation can be reduced by controlling the heat extraction in the secondary cooling zone. Hence, an accurate knowledge of boundary condition and the transient phenomenon occurring during the process is required for process optimization.weiterlesen