Heat Transfer Calculation And Visualization Research Of Mould Powder In Round Billet Continuous Casting

Mould powder is one of the crucial technologies in continuous casting process. Its properties have important effect on the technical operation and billet's quality. The research of mould powder is usually classified into two parts according to geometry domain: gap slag and surface powder. More work has developed about the lubrication status and fluid behavior of gap slag and many breakthroughs have achieved. While surface powder's behavior plays an important role on the liquid steel's initial solidification and billet's surface quality and directly affects liquid slag's filtration and lubrication. In this paper, a 3D mathematical model about the surface powder's thermal behavior was established and corresponding numerical calculation was conducted on the base of billet and mould's temperature calculation. The measured mould temperature data of the steel plant's continuous casting round billet was used as the calculation initial input and the foundation of model's testing. The effect of powder's physical property and related technical parameter on the thermal distribution of surface powder layers was emphasized. Furthermore, an experimental expression was introduced and corrected combined with round billet production to calculate the thickness of gap slag. And the powder consumption was also calculated.The results suggest that temperature of surface powder increase gradually from the powder surface to meniscus and the increase was quickened when temperature was close to the melting point. The liquid layer of powder is 9mm thick and the sintered one is 11 mm or so. The heat transfer coefficient, melting heat and melting temperature of mould powder have predominant effects on the liquid layer's thickness. The thickness of liquid layer increases with heat conduction coefficient's increase and melting heal/temperature's decrease. Properly improvement of casting speed is helpful to increase the liquid layer and assist it to reach the steady thickness. The slag film between the billet and mould is about 1mm and the liquid film is about 0.1mm. Powder consumption of round billet with 180mm diameter is 0.135 Kg/m2 which is consistent with measured value cited from relevant literature.Moreover, the calculation data was used to realize the high quality and alternate visualization image show on the Visual C++ development platform and OpenGL technology,which provide an immediate post-process method of billet/mould/powder. The animation of surface powder's thermal distribution was also realized. It accelerates the data process speed and the timely new data can be used more effectively, which made it possible that human being may communicate with data in image.