废杂铜再生水平连铸黄铜铸坯的宏观偏析

Macro Segregation of Horizontal Continuous Casting Brass Blanks Produced Using Recycled Copper Scrap

以废杂铜再生生产的水平连铸黄铜铸坯为研究对象,研究铸坯中元素的宏观偏析,以及铸坯直径对宏观偏析的影响。结果表明,铸坯下表面处铜含量最低,从下到上其含量逐渐增加,在距离铸坯底部约30 mm处,铜含量有一个明显的增加,而后一直到铸坯的顶部,其变化幅度很小。铸坯下表面处铅含量最高,而后呈快速下降的变化规律,在20 mm内下降了约1.1%,再向铸坯的顶部变化时,总体上分布比较均匀,在130 mm内,最大波动约为0.21%。在同样的连铸条件下,减小铸坯直径,可以部分的降低宏观偏析的幅度,但是宏观偏析区域所占比例不会明显的减小。铜的分布不均匀主要是由于铅的分布不均匀造成的,并提出了解决铅偏析的方法。

The macro segregation and the effect of diameter of casting blank on the macro segregation in horizontal continuous brass casting blank produced using copper scrap as raw material were studied.The results show that copper content is the lowest on the bottom surface of casting blank,and the content gradually increases from bottom to top.The copper content sharply increases at about 30 mm distance from the bottom of casting blank,and then the variation amplitude is very small up to the top of casting blank.Lead content is the highest on the bottom surface of casting blank and then rapidly decreases 1.1% within 20 mm distance from the bottom,and then lead distribution is relatively uniform from that position to the top.The biggest fluctuation of lead element is 0.21%.Under the same continuously casting condition,the macro segregation can be partly decreased through reducing the diameter of casting blank,but the macro segregation region will not be significantly reduced.The uneven distribution of copper is mainly caused by the uneven distribution of lead,and several methods for solving lead segregation are suggested.