Basic phenomena of the twin-roll casting have been investigated by paraffin model casting, thermal analysis and steel casting experiments. The influence of the roll gap on roll-bonding behavior of the solidified shells and temperature distribution of the molten pool have been mainly investigated by paraffin model casting. On the other hand, the change of the molten pool temperature during casting has been calculated by the numerical analysis method. Based on the results of these simulations, twin-roll casting of the steel has been carried out.
Through these experiments and numerical simulation, it has been recognized that roll gap relates closely to segregation, crack occurence and breakout of the cast strip, and the decrease of the molten pool temperature. An appropriate roll gap should be a gap which does not cause breakout, but minimizes the squeezing out the mushy-state layer. It is also found that the tendency of segregation and crack occurence in the steel strip are well explained by paraffin model casting.