Effects of surface treatments on the corrosion and erosion-corrosion of 304 stainless steel in 3.5% NaCl solution

Effects of citric acid treatment, nitric acid treatment and potentiostatic treatment on the corrosion resistance and erosion-corrosion behavior of 304 stainless steel in 3.5 wt.% NaCl solution containing 2 wt.% sand particles have been investigated by electrochemical methods. The result indicates that all treatments contribute to a significant improvement of corrosion resistance due to the formation of a Cr oxide-rich passive film. However, only citric acid treatment increases the critical flow velocity and erosion-corrosion resistance of 304 stainless steel under impingement. Passive film formed on the nitric acid treated stainless steel is easily destroyed by sand particles. (C) 2016 Elsevier Ltd. All rights reserved.