In-situ CPT of Duplex Stainless Steels in Artificial Seawater Using ECN

ABSTRACT This paper describes a novel methodology to measure the Critical Pitting Temperature (CPT) of a Duplex Stainless Steels (DSS) in artificial seawater based on the Electrochemical Noise (ECN) technique. The work presented here shows, for the first time, simultaneous in-situ micro-visualizatio...

Full description

Saved in:
Bibliographic Details
Published inNACE International Corrosion Conference Proceedings pp. 1 - 13
Main Authors GARFIAS-MESIAS, L F, Taylor, S R
Format Conference Proceeding
LanguageEnglish
Published Houston NACE International 01.01.2017
Subjects
Alloys
Composition
Corrosion
Duplex stainless steels
Electrochemical noise
Electrodes
Gas industry
Grain boundaries
Heat
Heat treatment
Localized corrosion
Microelectrodes
Microscopy
Noise
Seawater
Stainless steel
Uniform attack (corrosion)
Online AccessGet full text

Cover

More Information
Summary:ABSTRACT This paper describes a novel methodology to measure the Critical Pitting Temperature (CPT) of a Duplex Stainless Steels (DSS) in artificial seawater based on the Electrochemical Noise (ECN) technique. The work presented here shows, for the first time, simultaneous in-situ micro-visualization and CPT of two 25Cr Duplex Stainless Steel (DSS) microelectrodes with the same composition and heat treatment while immersed in artificial seawater. A recent publication5 by the author warns about the use of the PREN as the only requirement for CRAs selection and suggests that the qualification procedure should include fundamental testing to understand the factors that contribute to the degradation, e.g., general corrosion and/or localized corrosion of the alloy in the expected environmental conditions. Microelectrode Composition The samples where the microelectrodes were extracted were analyzed to find the composition of both the ferrite matrix and the austenite grains using a Scanning Electron Microscope (SEM) equipped with an Energy Dispersive Spectrometer (EDS), which provided X-ray mapping and particle analysis.