Menu
Search
Filters
Close
Menu

51318-10979-Pitting corrosion of steam generator tubing alloys in chloride solutions with thiosulfate additions

Picture for Pitting corrosion of steam generator tubing alloys in chloride solutions with thiosulfate additions
Available for download

Alloys UNS N06600, N06690 and N08800 are used for steam generator tubes. Pitting corrosion was studied in 0.1 to 1 M chloride solutions with additions of thiosulfate ranging from 10-4 M to 10-2 M, at room temperature. The alloys were tested in solution annealed and thermally aged conditions.

Product Number: 51318-10979-SG
Author: Abraham A. Becerra Araneda / Mariano A. Kappes / Martín A. Rodríguez / Ricardo M. Carranza
Publication Date: 2018
Industry: Science of Corrosion
$0.00
$20.00
$20.00

Alloys UNS N06600, N06690 and N08800 used for steam generator tubes are prone to pitting corrosion in aqueous chloride-thiosulfate solutions. Pitting corrosion was studied in 0.1 to 1 M chloride solutions with additions of thiosulfate ranging from 10-4 M to 10-2 M, at room temperature. The alloys were tested in solution annealed and thermally aged conditions. Potentiodynamic curves showed an anodic peak at potentials slightly higher than ECORR in N06690 and N08800 for both metallurgical conditions. This peak results from a localized corrosion process that was named low potential pitting corrosion (LPPC), because pits repassivated when potential was scanned in the noble direction, and also to distinguish it from the conventional chloride pitting process observed at higher potentials. Cyclic potential scans up to potentials in the LPPC zone showed a hysteresis loop and repassivation potentials (ERP,LPPC) were very close to ECORR measured under deaerated conditions. According to the measured values of ERP,LPPC, N06690 was more resistant to pitting corrosion than N08800. Immersion tests in aerated 1 M NaCl with [Cl-]/[S2O32-] = 2000 led to pitting corrosion in all alloys, while in deaerated conditions, only N08800 was pitted.

Key words: N06600, N06690, N08800, localized corrosion, thiosulfate, chloride

Alloys UNS N06600, N06690 and N08800 used for steam generator tubes are prone to pitting corrosion in aqueous chloride-thiosulfate solutions. Pitting corrosion was studied in 0.1 to 1 M chloride solutions with additions of thiosulfate ranging from 10-4 M to 10-2 M, at room temperature. The alloys were tested in solution annealed and thermally aged conditions. Potentiodynamic curves showed an anodic peak at potentials slightly higher than ECORR in N06690 and N08800 for both metallurgical conditions. This peak results from a localized corrosion process that was named low potential pitting corrosion (LPPC), because pits repassivated when potential was scanned in the noble direction, and also to distinguish it from the conventional chloride pitting process observed at higher potentials. Cyclic potential scans up to potentials in the LPPC zone showed a hysteresis loop and repassivation potentials (ERP,LPPC) were very close to ECORR measured under deaerated conditions. According to the measured values of ERP,LPPC, N06690 was more resistant to pitting corrosion than N08800. Immersion tests in aerated 1 M NaCl with [Cl-]/[S2O32-] = 2000 led to pitting corrosion in all alloys, while in deaerated conditions, only N08800 was pitted.

Key words: N06600, N06690, N08800, localized corrosion, thiosulfate, chloride

Product tags
Also Purchased
Picture for INFLUENTIAL FACTORS RELATED TO LOCALIZED CORROSION OF MILD STEEL IN SLIGHTLY SOUR ENVIRONMENTS
Available for download

51318-10984-INFLUENTIAL FACTORS RELATED TO LOCALIZED CORROSION OF MILD STEEL IN SLIGHTLY SOUR ENVIRONMENTS

Product Number: 51318-10984-SG
Author: Wei Zhang / Bruce Brown / David Young / Srdjan Nesic / Marc Singer
Publication Date: 2018
$20.00

A comprehensive parametric study was performed using a small-scale laboratory setup with the aim of investigating the occurrence of localized corrosion of mild steel in marginally sour environments.
Picture for Localized Corrosion of Mild Steel under Iron Sulfide Layers in CO2/H2S Environment
Available for download

51318-10990-Localized Corrosion of Mild Steel under Iron Sulfide Layers in CO2/H2S Environment

Product Number: 51318-10990-SG
Author: Saba Navabzadeh Esmaeely / Gheorghe Bota / Bruce Brown / Srdjan Nesic
Publication Date: 2018
$20.00

Mild steel specimens (API 5L X65) were pretreated to form a pyrrhotite layer on the surface using high temperature sulfidation in oil, then exposed to a range of aqueous CO2 and H2S corrosion environments, leading to initiation of localized corrosion.

 
Picture for Effect of Alloying Elements on the Corrosion Behavior of Carbon Steel in CO2 Environments
Available for download

51318-10997-Effect of Alloying Elements on the Corrosion Behavior of Carbon Steel in CO2 Environments

Product Number: 51318-10997-SG
Author: Yoon-Seok Choi / Srdjan Nesic / Hwan-Gyo Jung
Publication Date: 2018
$20.00

The objective of the present study was to evaluate the effect of alloying elements (Cr, Mo and Cu) on the corrosion behavior of low carbon steel in CO2 environments. Six samples were prepared with varying Cr content from 0 to 2 wt.% and with added 0.5 wt.% of Mo and Cu.
Categories
Industry
Recently viewed
Popular tags
View all

Association for Materials Protection and Performance

© AMPP All Rights Reserved.
Membership Terms of Content Use
Contact Customer Support