Reduction of Surface Cracking on Al-4.6%Mg Strips Cast Using a Vertical-Type High-Speed Twin Roll Caster with a Grooved Roll

Abstract

A roll with a groove was used to decrease surface cracking on strips cast using a vertical-type high-speed twin roll caster. The roll speed was 30 m/min. Al-4.6%Mg alloy was used because surface cracking easily occurs during roll casting of this alloy. The effect of roll load on the occurrence of surface cracks in Al-4.6%Mg was investigated before the grooved roll was evaluated. Importantly, surface cracking decreased as the roll load decreased. The roll load between the edges, that is, at the groove, became smaller than that at the edges corresponding to the flanges that formed the groove. The relationship between the depth of the groove and the occurrence of cracking was investigated. The groove on the roll was useful for reducing the number of cracks. However, cracking occurred at the center of the width direction. The cause of this cracking is discussed.