| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily set the direction of residual compressive stress given to steel to be the same as that of the stress exerted in the steel, and to improve the dimensional accuracy by suppressing the distortion. SOLUTION: The steel is twisted in a range in which no plastic deformation is generated, a part with the tensile stress exerted in the state is heat-treated, and untwisted after the cooling. The total of the difference of the residual tensile stress subtracted from the tensile stress exerted in the heat-treated part, and the stress added by the stress generated when a non-treated part is restored to an original shape by elasticity is remained as the compressive stress. The residual compressive stress in the steel is balanced by this treatment in the forward and reverse directions.</p> |
