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研究了锌铜合金在电磁场下水平连铸坯的初生坯壳前沿位置变化规律,考察了铸坯横截面宏观组织、微观组织形貌及合金元素的分布。试验结果表明,坯壳前沿的位置是随着拉坯速度、浇注温度和电流强度的变化而变化的,其中尤以拉坯速度对其的影响最为明显。只有根据电流强度和浇注温度相对应调整拉坯速度才能达到改善组织和偏析的效果。较大的电流和拉坯速度促使坯壳前沿后移。当液-固界面位于冷却水套和搅拌器的交界处时,反偏析得到有效抑制。电磁场消除了普通水平连铸坯横截面组织不均匀、最后凝固点上移的现象。搅拌后上边缘和心部深灰色树枝状的富铜相并没有完全消失,只是尺寸略微变大,但边部和心部组织差异很小。当拉坯速度3 m/h、电流100 A时,边部和心部组织最为均匀细小,其他电流和频率时组织变化不大。Ti没有起到细化作用和抑制反偏析作用,反而使得液体变得粘稠,流动性变差。
The variation of the front position of primary shell of zinc-copper alloy in horizontal continuous casting billets under electromagnetic field was investigated. The macrostructure, microstructure and the distribution of alloying elements were investigated. The results show that the position of the front edge of the shell changes with the billet speed, pouring temperature and current intensity, especially the billet speed has the most obvious impact on it. Only according to the current strength and pouring temperature corresponding to adjust the casting speed in order to achieve the effect of improving the organization and segregation. Larger current and casting speed to promote the front edge of the shell forward. The reverse segregation is effectively suppressed when the liquid-solid interface is at the junction of the cooling jacket and the stirrer. Electromagnetic field to eliminate the ordinary horizontal cross-section of the cross-sectional organization is not uniform, the final freezing point up the phenomenon. After mixing, the upper edge and dark gray dendritic copper-rich phase in the heart did not disappear completely, but the size slightly increased, but the difference in the edge and heart tissue was very small. When the casting speed of 3 m / h, the current of 100 A, the edge and heart tissue is the most uniform small, other current and frequency changes in the organization. Ti does not play a refining role and inhibit the role of anti-segregation, but make the liquid become viscous, fluidity worsened.