水モデルを用いた佐藤鋳型内のマクロ組織の解析と対流の推測

抄録

To intuitively understand non-uniform solidification and macrosegregation during continuous or ingot casting, the solidification structure of a transparent ammonium chloride aqueous solution was observed using a bridging-inducing Sato mold. First, using a heat-resistant glass cell equipped with a chill plate, the crystal growth of ammonium chloride dendrites near the chill plate was In-situ observed, and also an appropriate cell design was considered. Furthermore, using a constant flow velocity manufacturing device equipped with an electromagnetic stirrer, the relationship between the dendrite growth behavior and the perpendicular liquid flow velocity was investigated, and finally the flow velocity near the dendrite was estimated inside the mold.

By installing the chill plate and cooling stainless steel plates, the non-uniform solidification conditions was able to reproduced which was observed in actual steel and numerical simulations. At the chill plate, the dendrite growth velocity was relatively uniform. However, at the bottom half of the mold, the growth velocity increased or decreased depending on the observation location and solidification time. The growth velocity of the primary and secondary arms of dendrites, which grew perpendicular to the liquid flow at various velocities, increased almost linearly with increasing flow velocity. Using the relationship between the liquid flow velocity and dendrite growth velocity, the flow velocity near the dendrites could be estimated from the growth behavior such as the orientation and velocity of the secondary dendrite arms.