抄録
The authors have succeeded in single pass large draught rolling of AZ31 and ZK60A magnesium alloy sheets by applying high speed rolling faster than 1000m/min with the starting sheet temperature below 200℃ without heating rolls. Heavy reduction larger than 60% was able to be applied by single pass without fracture of a rolled sheet even at room temperature. In this study, AZ31B and ZK60A sheets were rolled above 1000m/min. The microstructure and texture of rolled and quenched sheets were investigated. The rolled and quenched sheets showed fully recrystallized microstructure at higher reduction. The microstructure was homogeneous throughout the thickness. The finest recrystallized grain size was 2.2μm for AZ31B and 2.8μm for ZK60A sheets. These are much finer than that of commercially available sheets. The texture of sheets rolled above 100℃ was double peak texture in which the position of accumulation of (0001) poles tilts 15 to 20 degrees away from the sheet normal direction to front and reverse direction along RD axis.
