Coil material and method for manufacturing the same

A coil material characterized by

• being formed from a cast sheet of a magnesium alloy,
• having a thickness of 7 mm,
• having an elongation at room temperature of 10% or less, and
• being coiled into the shape of a cylinder.

A coil material coiler to coil a sheet material continuously produced with a continuous casting machine into the shape of a cylinder, the coiler characterized by comprising:

• a chuck portion to grasp an end portion of the sheet material;
• and
• a heating device to heat the region, which is grasped by the chuck portion, of the sheet material,
• wherein the sheet material is formed from a magnesium alloy.

A method for manufacturing a coil material through coiling of a sheet material formed from a metal into the shape of a cylinder so as to produce the coil material, the method characterized by comprising the step of:

• coiling the sheet material with a coiler while the Centigrade temperature T of the sheet material just before coiling is controlled to be a temperature at which the surface strain, (t/R) ×100, wherein t represents the thickness and R represents the bending radius in millimeters, of the sheet material becomes less than or equal to an elongation at room temperature of the sheet material, wherein T is higher than 100,
• wherein the controlling of the Centigrade temperature T of the sheet material just before coiling, is applied to a place grasped by a chuck portion provided in the coiler;
• wherein the sheet material is a cast material of a magnesium alloy discharged from a continuous casting machine and the thickness t thereof is 7 mm or less, and a cast coil material having an elongation at room temperature of 10% or less is obtained,
• characterized in that the temperature of the sheet material is controlled in such a way as to make the temperature T of the sheet material just before coiling satisfy the following formula, where the minimum bending radius in coiling with the coiler is represented by Rmin, in millimeters:
• (
• T
• -
• 80
• )
• 2
• 450
• +
• 30
• 4000
• ≧
• t
• R
• ⁢
• ⁢
• min
• .
• [
• Equation
• ⁢
• ⁢
• 2
• ]