3000系列铝合金板带连铸连轧工艺基础研究

In twin-belt continuous cast (CC) processing, the molten metal is poured between two rotating steel belts to produce a cast slab, and then the slab is immediately fed into three consecutive hot rolling mills, forming hot band products. Aluminum sheet produced by the CC processing provides an energy savings of at least 25% and an economic savings of more than 14% over sheet made from conventional direct chill (DC) cast ingots. However, the formability of CC aluminum sheets is somewhat inferior to that of their DC counterparts after the same down stream processing. Therefore, to improve the formability of CC aluminum sheets is currently a key technology problem to be solved in the aluminum industry. The goal of the proposed research project is to investigate the evolution of microstructure and texture during the CC processing of AA 3000 series aluminum alloys, to establish the mathematical formulae for the volume fraction of recrystallized grains, grain size and texture volume fractions as a function of processing parameters, to analyze quantitatively structural factors affecting the evolution of microstructure and texture, and to reveal the formation mechanism of M and P recrystallization textures by EBSD. The grain structures of in-line anneal continuous cast aluminum sheets are evaluated for processing of ultra-fine grain aluminum alloys. The tensile properties, earring value and Olsen value of aluminum sheets under conditions of various processing parameters are measured, and the effect of M and P recrystallization textures on the formation of aluminum sheets is determined. A mathematical model for the relationship between earing profile and texture/grain shape coefficients is established by using Man's theories, and the quantitative relation between earing value and texture volume fractions is obtained for quality improvement of CC aluminum sheets.

铝合金板带连铸连轧工艺是将熔融铝液注入到滚动的钢带之间，连续铸造出板坯，经在线热连轧成板材。与热轧工艺相比，该工艺不但简化工艺流程，降低生产成本，还节约大量能源。然而在相同后序工艺条件下，其成形性却低于传统的热轧板材，如何提高铝合金板材的成形性是当前需要解决的关键技术问题。本项目拟系统研究3000系列铝合金板带连铸连轧加工过程中微结构和织构的演变，建立再结晶体积分数、再结晶晶粒尺寸和织构体积份数与加工参数的数学关系式，定量分析影响微结构和织构演变的因素，揭示M和P再结晶织构的形成机制；阐明在线快速加热条件下的晶粒细化机制，确定最佳的细晶铝合金加工工艺；评价不同工艺下铝合金板材的力学性能和成形性，确定M和P再结晶织构对板材成形性的作用；扩展Man的理论，推导制耳轮廓与织构系数和晶粒形状系数的关系式，建立制耳率与织构体积分数的数学关系式，为高性能铝合金板材的开发和应用奠定理论基础。

铝合金板带连铸连轧工艺是将熔融铝液注入到滚动的钢带之间，连续铸造出板坯，经在线热连轧成板材。与热轧工艺相比，该工艺不但简化工艺流程，降低生产成本，还节约大量能源。然而在相同后序工艺条件下，其成形性却低于传统的热轧板材，如何提高铝合金板材的成形性是当前需要解决的关键技术问题。本项目系统研究了3000系列铝合金板带连铸连轧加工过程中微结构和织构的演变，建立了再结晶体积分数、再结晶晶粒尺寸和织构体积份数与加工参数的数学关系式，定量分析了影响微结构和织构演变的因素，揭示了M和P再结晶织构的形成机制；阐明了在线快速加热条件下的晶粒细化机制，确定了最佳的细晶铝合金加工工艺；获得了不同工艺下铝合金板材的力学性能和成形性，确定了M和P再结晶织构对板材成形性的作用；扩展Man的理论，推导出制耳轮廓与织构系数和晶粒形状系数的关系式，建立了制耳率与织构体积分数的数学关系式，为高性能铝合金板材的开发和应用奠定理论基础。