Effect of Roll Load on Microstructure of Roll Cast Al-10%Mg Strip

Abstract

The effect of roll load on the microstructure of an Al-10%Mg strip cast using a vertcal-type high-speed twin-roll caster was investigated using roll stop and etching with Weck’s reagent. Roll stop was adopted to investigate the transformation of the microstructute near the roll bite. Weck’s reagent was used to visually determine the of the Mg solid-solution content. The roll load was 2, 88, or 420 N/mm and the roll speed was 30 m/min. A band zone formed at the center of the thickness direction for all roll loads. The Mg solid-solution content in the αAl in the band zone obtained at a roll load of 2 N/mm was greater than that obtained at roll loads of 88 and 420 N/mm. Recrystalization migh occur in the band zone of the strip at a roll load of 2 N/mm. The Mg solid-solution content in αAl near the surface was greater than that inside the strip in the thickness direction. The Mg solid-solution content in αAl near surface obtained at a roll load of 2 N/mm was greater than that obtained at roll loads of 88 and 420 N/mm.