COMPOSITE SHEET HAVING ENHANCED DUCTILITY DURING COLD ROLLING, METHOD FOR COLD ROLLING USING THE SAME, METHOD FOR MANUFACTURING ROLLED SHEET USING THE SAME, AND ROLLED SHEET MANUFACTURED THEREBY

摘要

The present invention relates to a composite plate having an improved ductility during cold-rolling, a method of cold-rolling and a method of manufacturing a rolled plate using the composite plate, and a rolled plate manufactured by the methods. Specifically, the present invention relates to the composite plate having an improved ductility during a cold-rolling process including a plate made of a first material and a constraining member made of a second material and suppressing plastic deformation of the plate in the transverse direction, the method of cold-rolling and the method of manufacturing a rolled plate using the composite plate, and the rolled plate manufactured by the methods. According to the present invention, when cold-rolling is performed using the composite plate having an improved ductility during the cold-rolling process including the plate and the constraining member, the constraining member applies compressive stress in the transverse direction of the plate while the rolling process is performed to prevent generation of an edge crack, and a tensile twinning is formed to remarkably improve the ductility of the plate. Therefore, materials such as magnesium or magnesium alloy having low formability in low temperatures and had problems such as high costs due to hot processing and process complication can be used in manufacturing a high-quality plate which can be usefully used in various technical fields such as automobiles, aircrafts, and so forth, by the cold-rolling of the present invention.