IMPROVEMENT OF RESIDUAL STRESS

摘要

PURPOSE:To decrease residual stress without cooling the surface having residual stress by subjecting the surface on the side opposite from the surface having the residual stress to high frequency induction heating at the frequency corresponding to the thickness of the plate then cooling the heated surface of itself. CONSTITUTION:A flat plate 5 is subjected to high frequency heating by an induction heating coil 4 from the surface 6 side of the plate 5 to generate such a temp. distribution as shown in the figure. There is a need for heating the plate at the high frequency as the thickness is smaller and therefore such a temp. distribution as shown in the figure is not realized unless the frequency corresponding to the plate thickness is selected. Then the plate is held compressed on the high temp. side (heated surface side) and held tensed on the lower temp. side in proportion to the temp. difference. If the plate is naturally cooled, the residual stress is reduced without cooling the surface having the residual stress.