Effect of Ultrasonic Impact Strengthening on Surface Properties of 316L Stainless Steel Prepared by Laser Selective Melting

Abstract

In order to study the effect of ultrasonic impact (UIP) on the microstructure and properties of 316L stainless steel prepared by selective laser melting (SLM), the hardness of the surface layer and depth direction of the sample were tested with a micro hardness tester. Finally, the friction and wear test of the sample was assessed using a friction and wear tester. The electrochemical corrosion test was carried out on the samples before and after the ultrasonic shock using a CHI660E electrochemical workstation. The results show that after the ultrasonic impact on the 316L stainless steel prepared by SLM, the surface produces plastic deformation and work hardening, which improves the hardness of the material surface and enhances the wear resistance of the sample surface. With ultrasound shocks affecting the near surface of the sample, a deformation layer of about 100 μm depth is formed. After the ultrasonic shock treatment, the self -corrosion potential of the sample in the 3.5% NACl solution is slightly higher than the unproofed sample, and the density of the self -corrosion current is also lower than the unproofed sample., indicating that ultrasonic shock can reduce the corrosion rate of the material surface and enhance the abrasion resistance of the sample surface.