Fig. 1 Typical profiles of current density versus time for electropulses produced by capacitors connected in series and in parallel

Fig. 2 Surface residual stress of approximately 70 as-quenched samples before and after electropulsing treatment at different current densities: a 3942 A/mm2, b 4482 A/mm2, c 5184 A/mm2, d 5562 A/mm2. Square and circular points with the same serial number correspond to the same sample before and after electropulsing treatment, respectively

Fig. 3 Residual stresses of the as-quenched sample and electropulsed samples at different depths

Fig. 4 Residual stress reduction in the samples with initial residual stresses ranging from 50 to 500 MPa after electropulsing treatment at different current densities: a 3942 A/mm2, b 4482 A/mm2, c 5184 A/mm2, d 5562 A/mm2

Fig. 5 Residual stress reduction rate versus current density

Fig. 6 Plastic strain \(\Delta \varepsilon_{\text{p}}\) versus current density. The solid line is the experimentally obtained relationship between the plastic strain and the current density of six groups of samples, where the initial residual stress of the samples in each group was the same. The dashed lines are the experimental results of Conrad [13]

Fig. 7 TEM images of a as-quenched sample, b sample treated by electropulsing at a current density of 5184 A/mm2. These samples were observed from the [110] direction

Fig. 8 Determination of dislocation line directions. a Image obtained in the [001] beam direction. The dislocation lines are 65° from the horizontal. b Image obtained in the [023] beam direction. The dislocation lines are 58° from the horizontal. The samples were treated by electropulsing at a current density of 5184 A/mm2