Effect of Weak Acid Additions on the General and Localized Corrosion Susceptibility of Alloy 22 in Chloride Solutions

2008 ◽  
Vol 1107 ◽  
Author(s):  
Ricardo M. Carranza ◽  
C. Mabel Giordano ◽  
Martín A. Rodríguez ◽  
Raul B. Rebak
Keyword(s):  
Organic Acids ◽  
Crevice Corrosion ◽  
Electrochemical Impedance ◽  
Dissociation Constants ◽  
Formation Constants ◽  
Localized Corrosion ◽  
Acid Dissociation ◽  
Complex Formation Constants ◽  
Chloride Solutions ◽  
Alloy 22

AbstractElectrochemical studies such as cyclic potentiodynamic polarization (CPP) and electrochemical impedance spectroscopy (EIS) were performed to determine the corrosion behavior of Alloy 22 (N06022) in 1M NaCl solutions at various pH values from acidic to neutral at 90°C. All the tested material was wrought Mill Annealed (MA). Tests were also performed in NaCl solutions containing weak organic acids such as oxalic, acetic, citric and picric acids.Results show that the CR of Alloy 22 was significantly higher in solutions containing oxalic acid than in solutions of pure NaCl at the same pH. Citric and Picric acids showed a slightly higher CR, and Acetic acid maintained the CR of pure chloride solutions at the same pH. Organic acids revealed to be weak inhibitors for crevice corrosion. Higher concentration ratios, compared to nitrate ions, were needed to completely inhibit crevice corrosion in chloride solutions.Results are discussed considering acid dissociation constants, buffer capacity and complex formation constants of the different weak acids.

Localized Corrosion Susceptibility of Alloy 22 in Chloride Solutions: Part 1—Mill-Annealed Condition

CORROSION ◽  
2005 ◽  
Vol 61 (11) ◽  
pp. 1078-1085 ◽  
Author(s):  
D. S. Dunn ◽  
Y-M. Pan ◽  
L. Yang ◽  
G. A. Cragnolino
Keyword(s):  
Localized Corrosion ◽  
Annealed Condition ◽  
Chloride Solutions ◽  
Alloy 22 ◽  
Corrosion Susceptibility

Localized Corrosion Susceptibility of Alloy 22 in Chloride Solutions: Part 2—Effect of Fabrication Processes

CORROSION ◽  
2006 ◽  
Vol 62 (1) ◽  
pp. 3-12 ◽  
Author(s):  
D. S. Dunn ◽  
Y-M. Pan ◽  
L. Yang ◽  
G. A. Cragnolino
Keyword(s):  
Localized Corrosion ◽  
Chloride Solutions ◽  
Alloy 22 ◽  
Corrosion Susceptibility

Studies of reagents for spectrophotometric measurement of ionic magnesium

1977 ◽  
Vol 55 (22) ◽  
pp. 3909-3914 ◽  
Author(s):  
Dennis G. McMinn ◽  
Byron Kratochvil
Keyword(s):  
Complex Formation ◽  
Dissociation Constants ◽  
Formation Constants ◽  
Acid Dissociation ◽  
Disulfonic Acid ◽  
Acid Dissociation Constants ◽  
Spectrophotometric Measurement ◽  
Ph Range ◽  
Metal Ligand ◽  
The Ideal

Four mono-azo aryl dyes having the o-carboxy-o′-hydroxy functionality were investigated as reagents for the measurement of ionic Mg2+ in solutions containing complexing ligands. 2-(2′-Carboxyl-1′-benzeneazo)-1,8-dihydroxynaphthalene-3,6-disulfonic acid came closest to the ideal of having absorbance unaffected by pH over the pH range of interest and of differentiating between Ca2+ and Mg2+ complex formation. Ligand acid dissociation constants and formation constants for the metal–ligand complexes were measured.

Anodic Behavior of Alloy 22 in High Nitrate Brines at Temperatures Higher Than 100°C

2006 ◽  
Author(s):  
Gabriel O. Ilevbare ◽  
Robert A. Etien ◽  
John C. Estill ◽  
Gary A. Hust ◽  
Ahmet Yilmaz ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Crevice Corrosion ◽  
Silver Chloride ◽  
Current Work ◽  
Anodic Behavior ◽  
Chloride Solutions ◽  
Electrochemical Tests ◽  
Alloy 22 ◽  
High Chloride

Alloy 22 (N06022) may be susceptible to crevice corrosion in chloride solutions. Nitrate acts as an inhibitor to crevice corrosion. Several papers have been published regarding the effect of nitrate on the corrosion resistance of Alloy 22 at temperatures 100°C and lower. However, very little is known about the behavior of this alloy in highly concentrated brines at temperatures above 100°C. In the current work, electrochemical tests have been carried out to explore the anodic behavior of Alloy 22 in high chloride high nitrate electrolytes at temperatures as high as 160°C at ambient atmospheres. Even though Alloy 22 may adopt corrosion potentials in the order of +0.5 V (in the saturated silver chloride scale), it does not suffer crevice corrosion if there is high nitrate in the solution. That is, the inhibitive effect of nitrate on crevice corrosion is active for temperatures higher than 100°C.

scholarly journals Potentiometric and UV Spectral Studies of Binary and Ternary Complexes of Some Metal Ions withN-Acetylcysteine and Amino Acids

2009 ◽  
Vol 6 (s1) ◽  
pp. S117-S122 ◽  
Author(s):  
Shaesta Quyoom ◽  
Badr-Ud-Din Khan
Keyword(s):  
Amino Acids ◽  
Metal Ions ◽  
Aqueous Medium ◽  
Dissociation Constants ◽  
Formation Constants ◽  
Ternary Complexes ◽  
Acid Dissociation ◽  
Spectral Studies ◽  
Binary And Ternary Complexes ◽  
Structural Nature

The formation constants of the binary 1:1 and 1:2 complexes of Cu(II), Zn(II), Cd(II), Hg(II), and Pb(II) withN-acetylcysteine (NAC) and 1:1:1 ternary complexes of the said metal ions with NAC as a primary ligand and some biologically important amino acids as secondary ligands have been determined potentiometrically in aqueous medium. Acid dissociation constants of the ligands used and the formation constants of the binary and the ternary complexes were determined at 25 °C and in ionic strength I=0.1 mol dm-3(KNO3).The formation constants of the 1:1 complexes were found to be higher than 1:2 complexes and the metal ions follow the order Hg(II) >Cu(II) >Cd(II) >Zn(II). In addition UV-spectral studies of the NAC-Metal (II) complexes have also been conducted at appropriate pH values to give further information about the structural nature of NAC- Metal (II) complexes in aqueous medium.

Effect of Alloy Composition on the Localized Corrosion Resistance of Nickel Alloys

2012 ◽  
Vol 1475 ◽  
Author(s):  
Santiago Sosa Haudet ◽  
Martín A. Rodríguez ◽  
Ricardo M. Carranza
Keyword(s):  
Corrosion Resistance ◽  
Crevice Corrosion ◽  
Chloride Concentration ◽  
Testing Temperature ◽  
Localized Corrosion ◽  
Chloride Solutions ◽  
Equivalent Number ◽  
Engineered Barriers ◽  
Nickel Base ◽  
30 G 35

ABSTRACTNickel base alloys are considered among candidate materials for engineered barriers of nuclear repositories. The localized corrosion resistance is a determining factor in the materials selection for this application. This work compares the crevice corrosion resistance of selected nickel base alloys, namely 625, G-30, G-35, C-22, C-22HS and HYBRID-BC1. The crevice corrosion repassivation potential (ER,CREV) of the tested alloys was determined by the Potentiodynamic-Galvanostatic-Potentiodynamic (PD-GS-PD) method. The testing temperature was 60ºC and the chloride concentrations used were 0.1 M, 1 M and 10 M.A linear relationship between ER,CREV and the logarithm of chloride concentration was found. ER,CREV increased linearly with PREN (Pitting Resistance Equivalent Number) in concentrated chloride solutions. ER,CREV is the sum of three contributions: ECORR*, η and ΔΦ. ECORR* and η increased linearly with PREN, while ΔΦ increased linearly with PREN for concentrated chloride solutions, not showing a definite trend with PREN for the less concentrated solutions.

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