采用添加Na2B4O7的KCl-NaCl-Na3AlF6渣剂对浇注的工业纯铝自耗电极棒进行电渣精炼,以去除纯铝中的杂质铁,并改善其力学性能。结果表明:电渣精炼后纯铝中的铁含量随着Na2B4O7添加量和电渣重熔时间的增加而减少,在Na2B4O7添加量为9%和重熔时间为30min的情况下,铁含量从0.400%降低到0.184%。电渣精炼后,纯铝的弹性模量、屈服强度和抗拉强度得到改善,尤其是其延伸率提高了43%。铁含量降低的主要原因是电渣重熔过程中熔渣和铝液滴反应生成富铁相Fe2B。渣-液体系的反应热力学计算从理论上解释了Fe2B的生成。
The effect of electroslag refining on iron reduction from commercial aluminum was investigated.Cast electrodes of commercial aluminum were electroslag refined using KCl-NaCl-Na3AlF6 slag containing Na2B4O7.Experimental results indicate that the iron content decreases with increasing Na2B4O7 addition and remelting time,and the iron content decreases from 0.400% to 0.184% under 9% Na2B4O7 addition for 30 min remelting.The elastic modulus,yield strength and ultimate tensile strength commercial aluminum are improved,and the tensile elongation is increased by 43% after electroslag refining.The chemical reaction between melt and slag to form Fe2B is the main reason for iron reduction and the thermodynamic calculation of the chemical reaction theoretically accounts for the formation of Fe2B.