Prediction of Periodic Centerline Porosity and Pulse Marks by CFD and Experimentation for Continuously Cast Copper

Abstract For 8 mm OFCu rod, the formation of pulse mark defects on exterior rod and periodic macroporosity (> 1 diameter pores) occurring internally along centerline castings have been observed noted to limit maximum attainable withdrawal rates (~ 4 m/s). Conversely, same casting witnessed for slower rates; therefore, investigations were performed investigate how motions (withdrawal, dwell, pushback) formed these could be prevented. Characterization physical properties cast rods by tensile testing analysis optical computed tomography (CT) imaging revealed correlations outer pitch length marks confirmed relationships lengths evaluated from metallurgical equations. Computational fluid dynamic modeling using Ansys Fluent v.R1 was applied quantify localized dissipation hotspots within die different motions. A mechanism leading porosity identified, which irrespective average enabled prediction location, frequency, magnitude defect.