哈兹列特连铸连轧AA5052铝合金铸嘴挂渣成分及形成机理研究

Study on Composition and Mechanism of Nozzle Cavity Slag of Hazelett Continuous Casted and Rolled AA5052 Aluminum Sheet

采用SEM、EDS、XRD等方法研究了哈兹列特连铸连轧AA5052铝合金过程中铸嘴挂渣的成分和机理,并利用热力学吉布斯自由能计算了形成铸嘴挂渣结合物的驱动力,分析了挂渣结合物的反应形成过程.研究发现,铸嘴挂渣的主要成分为尖晶石、镁橄榄石、硅酸镁等.铸嘴中的SiO2或Al2O3与AA5052合金熔体中的Al、Mg和MgO等在铸造过程中长时间接触发生反应,生成尖晶石、镁橄榄石、硅酸镁等,其中主要是尖晶石成分,最终导致铸嘴挂渣.

This paper studied the dross composition and dross Mechanism of nozzle cavity on Hazelett continuous casted and rolled AA5052 aluminum alloy by scanning electron microscopy （SEM）,energy dispersive analysis （EDS）,X-ray diffraction （XRD）,etc.Using The Gibbs free energy thermodynamic function calculated driving forces of forming dross compound of nozzle cavity and analyzed formation on reaction of dross compound of nozzle cavity.The results showed that dross compound of nozzle cavity consisted of spinel,forsterite,Florisil,etc.The SiO2 or Al2O3 in nozzle cavity reacted with Al,Mg and MgO in AA5052 aluminum alloy melt to MgAl2O4,Mg2SiO4,MgSiO3,which were mainly spinel composition during casting process,eventually leading to dross of nozzle cavity.