Enhanced Pitting Corrosion Resistance of 304 SS in 3.5 wt% NaCl by Ultrasonic Nanocrystal Surface Modification

Abstract

© The Author(s) 2017. Published by ECS. All rights reserved. Surface nanocrystallization has been shown to increase corrosion resistance of metallic materials. Ultrasonic nanocrystal surface modification (UNSM) is a recently developed method, which utilizes low amplitude ultrasonic frequency vibrations superimposed on a static load to induce high strain rate plastic deformation on a material surface for grain refinement. The present work investigates the effective depth of the severe plastic deformation layer by UNSM treatment, identifies the microstructure change and phase transformation within this layer, and correlates them with the enhanced pitting corrosion resistance of 304 SS in 3.5 wt% NaCl solution.