Residual stress reduction by pulsed magnetic treatment

Residual stress relief by pulsed magnetic treatment is attractive since the process is carried out at room temperature and magnetic fields that are easy to produce and control can be used. The extent of residual stress reduction due to a particular pulsed magnetic treatment was determined. Initially curved strip specimens were held flat to produce a known residual stress and then subjected to a pulsed magnetic treatment. Microhardness measurements before and after treatment and a mechanical model relating stress and indentation size were used to specify the change in residual stress due to pulsed magnetic treatment. Changes of stress near the surface of the specimens due to treatment were obtained. Reductions of residual stress of 4% - 7% were obtained for the particular pulsed magnetic treatment used on lower initial stress level specimens. For a higher initial stress level stress reductions of 8% - 13% were measured.