| 摘要 |
PURPOSE: To prevent the occurrence of defects, such as crack, by introducing compressive residual stress to a metal surface, to prevent the influence of the quality of the material to be treated, and to increase the applicability to the existing material to be treated. CONSTITUTION: The metal surface 1a of a material 1 to be treated is heated into spotted state. Then, a heating point P is successively shifted, and the metal surface 1a in a high-temp. state is cooled rapidly to apply a thermal stress exceeding the yield point. Subsequently, cooling is applied down to uniform temp. to establish compressive residual stress in the metal surface. Spot heating is performed by laser beam, etc. |
