Enhancement of abrasion and corrosion resistance of duplex stainless steel by laser shock peening

Abstract

The results for laser shock peening of duplex stainless steel (22% Chromium-5% Nickel) using a pulsed Nd:YAG laser (wavelength =532 nm, pulse width = 8 us) for the application to high-capacity pumps for reverse-osmosis type seawater desalination plants are reported. By properly selecting the process parameters such as laser intensity of 10 GW/cm(2), laser pulse density of 75 pulse/mm(2), and 100 mu m thick aluminum foil as a protective coating layer, wear volume and corrosion rate of duplex stainless steel could be reduced by 39% and 74.2%, respectively.The number and size of corrosion pits produced on wear track during copper accelerated acetic acid salt spray test decreased approximately by half as a result of laser shock peening. It is shown that laser shock peening is a practical option to improve abrasion and corrosion properties of a seawater desalination pump parts. (C) 2012 Elsevier B.V. All rights reserved.