Electrochemical noise analysis of duplex stainless steel 2101 exposed to different corrosive solutions

Abstract

The corrosion behaviour of duplex stainless steel 2101 exposed to 0.1 wt-%NaOH, 5.0 wt-%H₂SO₄ and 6.0 wt-%FeCl₃ solutions was investigated with an electrochemical noise technique. The time records revealed salient features of the steel in the three solutions, and the corresponding corrosion morphologies were shown. The slopes of the power spectral density plots of current and potential noises were associated with the nature of corrosion attack. The corrosion rates in the three media were reflected by the noise resistance, presenting good correlation with the results from linear polarisation and electrochemical impedance spectroscopy.

Keywords:

• Duplex stainless steel
• Electrochemical noise
• Linear polarisation
• EIS
• Corrosion mechanism