Patent ID: 7559221

Claim:
A method of working a metal, comprising the steps of cooling a metal body extending in one direction by a first cooling mechanism and a second cooling mechanism along the extending direction of the metal; heating the metal body by a heating mechanism provided between the first cooling mechanism and the second cooling mechanism thereby locally reducing the deformation resistance of the metal body and forming a low deformation resistance region crossing the metal body; and changing a position of a first non-low deformation resistance region relative to a second non-low deformation resistance region in the metal body in a state that the low deformation resistance region is sandwiched between the first non-low deformation resistance region and the second non-low deformation resistance region thereby deforming the low deformation resistance region by shearing to make the microstructure of the metal body fine, wherein the position change is caused by a vibration applied to the metal body in the direction approximately orthogonal to the extending direction of the metal body.