Effect of Coupling of Eletropulsing Treatment and Ultrasonic Surface Modification on the Surface Nanostructure Layer of Steel

Abstract

Abstract A coupling of eletropulsing treatment and ultrasonic surface modification (C-E-U) was employed to design the nanostructured layer materials with high strength and surface protection of 40Cr17Mo steels. The surface properties of the specimens after dry cutting, coupling of ultrasonic-eletropulsing treatment (CUE) and coupling of eletropulsing-ultrasonic treatment (CEU) were characterized, respectively. A grain refinement layer was formed on the specimen’s surface after the coupling of eletropulsing treatment and ultrasonic surface modification. The residual stress on the top surface was reduced. This is caused mainly by two aspects: one is the aggregation of subgrain boundaries during deformation in order to form new grain boundaries processed by the ultrasonic effect; the other is that the acceleration effect of electropulsing. Moreover, it was found out that electropulsing is very effective to release residual stress in the material surface.