Patent attributes
The method includes treating a metal sheet having a bcc structure and a surface satisfying conditions (a) or (b), molding the metal sheet to cause plane strain tensile deformation and biaxial tensile deformation, and allowing at least one part of the metal sheet to have a sheet thickness decrease rate of from 10% to 30%. Condition (a): an area fraction of crystal grains having a crystal orientation of 15° or less relative to a (001) plane parallel to a surface of the metal sheet is from 0.20 to 0.35. Condition (b): the area fraction of crystal grains having a crystal orientation of 15° or less relative to a (001) plane parallel to a surface of the metal sheet is 0.45 or less, the average crystal grain size thereof is 15 μm or less. The molded product satisfies conditions (a) or (b).
