連鋳鋳型内凝固におよぼす操業要因の影響  [in Japanese] Influence of Casting Conditions on the Solidification of Steel Melt in Continuous Casting Mold  [in Japanese]

Effects of high withdrawal rates, fluid mold slags, and mold taper on the occurrence of breakouts or surface cracks of the strand cast slabs have been evaluated by using an elasto-plastic stress analysis model previously developed. The model has made it possible to predict the air-gap formation, and hence hot spot formation at the corner portion of the shell/mold boundary as well as the stress mode in the shell. Choice has been made of casting conditions which can minimize the hot spot formation and yield compressive stress in the shell. Commercial scale casting experiments carried out on a Voest type straight mold and a Mannesmann type curved mold have confirmed that the chosen conditions are effective to prevent the breakout and crack formations of the shell. A mechanism of the formation of longitudinal corner cracks and longitudinal facial-cracks has also been discussed.