Electrochemical Corrosion Behavior of ER8 Wheel Steel in Neutral NaCl Solution

Abstract

In order to study the corrosion behavior of ER8 wheel steel in coastal neutral chlorine salt environment，the electrochemical corrosion behavior of ER8 wheel steel in neutral NaCl solutions with three different concentrations were analyzed through electrochemical tests， corrosion weight loss tests，scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques.The polarization curve results showed that the self-corrosion current density (Jcorr) was the largest in 5.0%(mass fraction， the same below) NaCl solution at the initial stage of immersion.After immersed for 576 h， Jcorr continued to increase at 2.0%and 3.5%NaCl solutions， and the average corrosion rate was more than 0.12 mm/a for 2 160 h.The SEM results indicated that the morphology of corrosion products were mainly flake and cluster structures.Because the morphology of corrosion products at the initial stage had more pores， it’s difficult to prevent Cl- from reacting with the substrate.The structure of corrosion products was more uniform and denser for 2 160 h.Moreover，the XRD results showed that the corrosion products were mainly composed of γ-FeOOH， α-FeOOH and Fe3O4.

Keywords

• wheel steel|er8|neutral nacl solution|corrosion rate|rust layer