キルド鋼塊における底部等軸晶帯の生成モデル

抄録

A fairly simple model is proposed, which explains the formation mechanism of equi-axed crystals and predicts the profile of equi-axed zone in ingots. The validity of the model is proved by comparing the results of the experiments with that of the calculation according to the model.
The results are as follows:
(1) Profiles of equi-axed crystal zone in ingots, calculated by the above model, well coincide with that observed on the macro solidification structure of ingots.
(2) The model is based on the assumption that the rate of equi-axed crystal formation is proportional to the volume of liquid/solid zone (interdendritic zone).
(3) Therefore, equi-axed crystals in ingot are formed mainly at solidification front (liquid/solid zone) and sediment to the bottom of ingot to form equi-axed crystal zone, when the pouring temperature of steel is high enough and the steel meniscus is well covered with the exothermic powder, which excludes "showering" from the meniscus.