摘要
用 Ｐｂ－５％Ｓｎ合金在垂直轴对称凝固的 φ７０ ｍｍ×１２０ｍｍ圆柱锭上模 拟了大型钢锭中Ａ偏析的形成，研究了Ａ偏析形成的临界导热条件。采用倾 角低速旋转法对轴对称凝固条件下通道偏析的防止作了初步尝试。结果表 明：通道偏析的形成条件是径向温度梯度大于７．５×１０－２°Ｃ／ｍｍ；凝固速度 小于临界凝固速度，临界凝固速度随着温度梯度的降低而降低。倾角低速旋 转可以有效地防止通道偏析的形成。当铸锭沿轴线倾斜２２°时，相对于绕垂直 轴旋转，防止偏析所需的转速可降低８０％．
Conditions for the formation and prevention of channel segregation have been studied in the lead-tin system, using a φ70 mm × l20 mm cylindrical mould. The results are summarized as follows: (1) Conditions for the formation of A-segregation in Pb-5%Sn alloy are that temperature gradient, G, must exceed 7. 5 × l0-2°C /mm and critical solidification rates decrease as temperature gradients decrease. (2) Mould rotation with slow rates, during the solidification, effectively prevent the formation or propagation of channel segregation. When axis is inclined to . the vertical by 22 deg, energy consumption to prevent channels is 20 per cent of that in the case of rotation around thd vertical axis.
出处
《大连理工大学学报》
EI
CAS
CSCD
北大核心
1992年第4期418-422,共5页
Journal of Dalian University of Technology
关键词
钢锭
凝固
偏析
糊状区
通道
channel
segregation
mushy zone
solidification
