High current density electropulsing was used to release quenched residual stress in 40Cr steel. It was found that residual stress began to release when the current density was higher than a certain value. And when the current density was up to 6.3 kA/mm^2, the residual stress could be completely released in 700 μs at a temperature rise of about 360 ℃. The main reason for the stress release was proposed to be that the yield stress of the material decreased due to the electroplastic effect of current, and at the same time, there was a thermal compressive stress induced by the high-rate heating process of electropulsing. The thermal compressive stress and the residual stress might caused plastic deformation of the sample and therefore realized residual stress release.
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