Abstract
The evolution of as-cast γ grain in low carbon steel has been investigated using thin slab cast simulator. Fine columnar γ grain evolved from the surface to the center of the ingot was obtained, and second dendrite arm spacing was investigated. The γ grain size for the present cooling rate of approximately 2˜20 K/s showed a relatively good agreement with the estimated value by the previously predicted line of d γ =1.52γ-0.5 for low carbon steels based on the Classical Grain Growth Model (CGGM). The effect of some elements was examined and it was proved that ferrite stabilizing elements such as phosphorus and tin have great effect of reduction of austenite grain size and copper has little effect on it. On the basis of the effect obtained, guiding principles for the control of the as-cast microstructure have been found.
