工艺参数对Zn-4.5Cu-0.2Mn-0.3Bi合金水平连铸坯反偏析及凝固组织的影响

发布时间：2018-05-31 14:44

本文选题：Zn-.Cu-.Mn-.Bi合金 + 电磁场　；参考：《稀有金属材料与工程》2015年10期

【摘要】：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。
[Abstract]:The variation law of the front position of the billet shell in the horizontal continuous casting billet under the electromagnetic field was studied. The macrostructure, microstructure and distribution of alloying elements in the cross section of the billet were investigated. The results show that the position of the shell front changes with the change of casting speed, pouring temperature and current intensity, especially the influence of billet drawing speed. Only by adjusting the casting speed according to the current intensity and pouring temperature can the structure and segregation be improved. The higher current and the speed of billet drawing make the shell front move backward. When the liquid-solid interface is located at the junction of the cooling water jacket and the stirrer, the reverse segregation is effectively suppressed. The electromagnetic field eliminates the phenomenon that the cross section of the common horizontal continuous casting billet is not uniform and the final freezing point is moving up. After stirring, the copper-rich phase of dark gray dendriform in the upper edge and the center did not completely disappear, but the size of the copper-rich phase increased slightly, but the difference between the edge and the center was very small. When the drawing speed is 3 m / h and the current is 100A, the structure of the edge and heart is the most uniform and fine, while the other current and frequency have no effect of thinning and inhibiting the reverse segregation, but make the liquid become viscous and the fluidity becomes poor.
【作者单位】：大连理工大学;宁波博威合金材料股份有限公司;
【基金】：国家自然科学基金(51071035,51375070) 高等学校博士学科点专项科研基金(20100041110030)
【分类号】：TG249.7

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