Behavior of nonmetallic inclusions in front of the solid-liquid interface in low-carbon steels
Behavior of nonmetallic inclusions in front of the solid-liquid interface in low-carbon steels
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DOI：
10.1007/s11663-000-0077-0
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发表时间：
2000-10-01
影响因子：
3
通讯作者：
Mizoguchi, S
中科院分区：
文献类型：
--
作者：
Kimura, S;Nabeshima, Y;Mizoguchi, S
本文研究了非金属夹杂物在运动固液界面前的相互作用现象。利用激光显微镜在高温实验中进行了原位观察。低氧铝镇静钢中的氧化铝夹杂物表现出众所周知的聚集行为。界面的前进速度在接近颗粒时先增大，但在吞噬过程中停滞，之后又增大。高氧加镁钢中的铝镁复合夹杂物在熔池中弥散分布。这些夹杂物在凝固过程中从前进界面逃逸，但在重熔过程中又在后退界面处聚集。这些微小的夹杂物被认为是局部流动的示踪粒子。在视频图像上测量了颗粒的速度，发现在界面附近有明显的加速或减速。得出的结论是，流动引起的马兰戈尼效应，由于在界面前的温度和氧含量的局部差异，特别是在较高的氧含量的情况下。然而，在低氧含量的情况下，流动较弱。
The present study is concerned with the interaction phenomena of nonmetallic inclusions in front of a moving solid-liquid interface. The in situ observation was done in a high-temperature experiment by using a laser microscope. Alumina inclusions in an aluminum-killed steel with low oxygen content exhibited the well-known clustering behavior. The velocity of the advancing interface first increased while approaching the particle, but became stagnant during engulfment and increased again after that. Alumina-magnesia complex inclusions in a magnesium-added steel with high oxygen content were very finely dispersed in the molten pool. These inclusions escaped from the advancing interface during solidification, but gathered again at the retreating interface during remelting. The tiny inclusions were thought to behave just as tracer particles of a local flow. The velocity of particles was measured on a video image, and the significant acceleration or deceleration was found near the interface. It was concluded that the flow was induced by the Marangoni effect due to the local difference in temperature and oxygen content in front of the interface, particularly in the case of a higher oxygen content. However, the flow was weak in the case of a low oxygen content.