Numerical Simulation On Solidification And Heat-transfer Of Hazelett Continuous Casting Of Aluminum Alloy Slab

Hazelett twin-belt continuous casting and rolling process is absorbing more and more attention of aluminum alloy plate and strip producers of the world for its advantages, such as short procedure, low energy consumption, low production cost and high productivity. Environment-friendly and high productivity continuous casting and rolling process is becoming main trend of aluminum alloy plate and strip processes. The conventional DC casting/hot mill process route include melting and alloying, DC casting, sawing, surface milling, rolling ingot preheating, and hot rolling(both roughing and finishing). The hot rolled strip is subsequently cold rolled to finish gauge. With twin-roll casting, the steps include melting and alloying, casting and coiling. The strip is subsequently cold rolled to finish gauge. In the twin-belt process, casting is followed by in-line hot rolling to produce a hot rolled strip that is thinner than twin-roll cast strip, requiring less subsequent cold rolling.The quality of Hazelett twin-belt continuous casting has big influence on the property of finished hot-rolled aluminum strip. The numerical simulation study on solidification and heat transfer of the twin-belt continuous casting is important to improve the surface quality, microstructure, and mechanical property of continuous casting aluminum strip and very helpful to take advantage of the heat in the as-cast strip to save energy and reduce the environmental impact, which is the biggest advantage of the Hazelett process. So it is very necessary to do some numerical simulation research on solidification and heat-transfer of Hazelett twin-belt continuous casting process.In this paper, a two-dimensional heat-transfer model which considers a generalized energy equation that is valid for the solid, liquid, and mushy zones in the Hazelett continuous cast was developed to simulate the solidification and heat transfer of twin-belt continuous casting of aluminum alloy slab by the finite element method under some assumptions. The heat transfer of Hazelett caster mold interface was described by an overall thermal resistance model. The steady state temperature field during the continuous casting was computed and the temperature distribution of slab surface, center and continuous casting exit was also computed when casting was close to steady state. the influence of process parameters such as casting speed, superheat and belt coat on temperature distribution was investigated. The result of calculation indicated as follows:(1) The Hazelett heat-transfer model built in this paper reflects mushy zone evolution, the length of liquid core and slab temperature distribution for the heat transformation process completely during Hazelett twin-belt continuous casting.(2) Continuous casting speed and twin-belt coat have big influence on temperature field, especially twin-belt caster exit temperature, super heat has much influence on the formation position of shell(3) Process parameters such as continuous casting speed, super heat, twin-belt coat have little influence on the temperature difference between center and surface of Hazelett casted slab, which is mainly influenced by twin-belt cooling condition...