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.

Effect of temperature on the crevice corrosion resistance of Ni-Cr-Mo alloys as engineered barriers in nuclear waste repositories

2012 ◽  
Vol 1475 ◽  
Author(s):  
Edgar C. Hornus ◽  
C. Mabel Giordano ◽  
Martín A. Rodríguez ◽  
Ricardo M. Carranza
Keyword(s):  
Corrosion Resistance ◽  
Crevice Corrosion ◽  
Chloride Concentration ◽  
Localized Corrosion ◽  
Effect Of Temperature ◽  
Corrosion Susceptibility ◽  
Engineered Barriers ◽  
Corrosive Environments ◽  
Waste Repositories

ABSTRACTNi-Cr-Mo alloys offer an outstanding corrosion resistance in a wide variety of highly corrosive environments. Alloys 625, C-22, C-22HS and HYBRID-BC1 are considered among candidates as engineered barriers of nuclear repositories. The objective of the present work was to assess the effect of temperature on the crevice corrosion resistance of these alloys. The crevice corrosion repassivation potential (ER,CREV) of the tested alloys was determined by the Potentiodynamic-Galvanostatic-Potentiodynamic (PD-GS-PD) method. Alloy HYBRID-BC1 was the most resistant to chloride-induced crevice corrosion, followed by alloys C-22HS, C-22 and 625. ER,CREV showed a linear decrease with temperature. There is a temperature above which ER,CREV does not decrease anymore, reaching a minimum value. This ER,CREV value is a strong parameter for assessing the localized corrosion susceptibility of a material in a long term timescale, since it is independent of temperature, chloride concentration and geometrical variables such as crevicing mechanism, crevice gap and type of crevice former.

URANUS 76N

Alloy Digest ◽  
2009 ◽  
Vol 58 (1) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
Physical Properties ◽  
Tensile Properties ◽  
Heat Treating ◽  
Localized Corrosion ◽  
High Chromium ◽  
Equivalent Number ◽  
Nitrogen Contents

Abstract URANUS 76N contains high chromium, molybdenum, and nitrogen contents and has a pitting resistance equivalent number (PREN) ≥ 40. These factors explain why the duplex austenitic/ferritic stainless grade is very resistant to localized corrosion. The alloy has been used for offshore applications. This datasheet provides information on composition, physical properties, tensile properties, and shear strength as well as fracture toughness. It also includes information on corrosion resistance as well as forming, heat treating, and joining. Filing Code: SS-1028. Producer or source: Industeel USA, LLC.

Localized Corrosion of Nuclear Grade Alloy 800 Under Steam Generator Layup, Startup and Operating Conditions

2012 ◽  
Vol 1 (1) ◽  
pp. 13-20 ◽  
Author(s):  
Y. Lu
Keyword(s):  
Corrosion Resistance ◽  
Steam Generator ◽  
Elevated Temperatures ◽  
Chloride Concentration ◽  
Operating Conditions ◽  
Nuclear Grade ◽  
Localized Corrosion ◽  
Pitting Potential ◽  
Alloy 800 ◽  
Secondary Side

The localized corrosion resistance of nuclear-grade Alloy 800, which is one of the preferred steam generator (SG) heat exchange tube materials of CANDU and PWR reactors, was studied under simulated SG secondary side crevice chemistry conditions at ambient temperature as well as at elevated temperatures. Series of cyclic potentiodynamic polarization tests were performed to study the localized corrosion resistance of Alloy 800 as a function of chloride ion concentration in the SG crevice solution at 40°C, 150°C and 300°C. Based on the experimental results, empirical equations were provided for calculating the pitting potential of nuclear grade Alloy 800 in the SG secondary side crevice chemistries with different levels of chloride concentration at SG layup, startup and operating temperatures.

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.

Localized Corrosion Resistance of Mn-Substituted Austenitic Stainless Steels: Effect of Molybdenum and Chromium

CORROSION ◽  
1976 ◽  
Vol 32 (7) ◽  
pp. 274-277 ◽  
Author(s):  
R. J. BRIGHAM ◽  
E. W. TOZER
Keyword(s):  
Corrosion Resistance ◽  
Stainless Steels ◽  
Crevice Corrosion ◽  
Composition Range ◽  
Austenitic Stainless Steels ◽  
Localized Corrosion ◽  
Critical Pitting Temperature

Abstract The pitting and crevice corrosion resistance of a number of Mn-substituted austenitic stainless steels has been determined quantitatively using temperature as a localized corrosion criterion. The go/no-go temperatures, the critical pitting temperature (CPT), and the crevice corrosion temperature (CCT) can be summarized by the equations and for Mn-substituted austenitic stainless steels over the composition range 0 to 5% Mo and 18 to 22% Cr. The resistance to localized corrosion of these Cr-Ni-Mn-Mo alloys is compared with that of Cr-Ni-Mo austenitic stainless steels.

Comparison of Several Accelerated Laboratory Tests for the Determination of Localized Corrosion Resistance of High-Performance Alloys

CORROSION ◽  
1983 ◽  
Vol 39 (3) ◽  
pp. 98-102 ◽  
Author(s):  
P. E. Manning
Keyword(s):  
Corrosion Resistance ◽  
High Performance ◽  
Laboratory Tests ◽  
Test Procedure ◽  
Localized Corrosion ◽  
Test Results ◽  
Ferric Ions ◽  
Nickel Base ◽  
Temperature Test

Abstract Results of immersion pitting, immersion crevice, and slow scan potentiodynamic pitting tests are compared to assess the relevance of particular types of accelerated laboratory tests for localized corrosion. The alloys examined include 317 L, 20-type alloys, duplex stainless steels, and nickel-base alloys. The solutions utilized are acid chloride-type with and without ferric ions [Fe2(SO4)3] as an oxidizing species. The acids examined include sulfuric, hydrochloric, and mixtures of these two acids. The best accelerated test for rating localized corrosion resistance of alloys is the immersion pitting temperature test. Results from this test procedure best simulate and correlate with the service performance of alloys.

URANUS B25

Alloy Digest ◽  
2004 ◽  
Vol 53 (9) ◽  
Keyword(s):  
Fracture Toughness ◽  
Corrosion Resistance ◽  
Shear Strength ◽  
High Temperature ◽  
Heat Treating ◽  
Localized Corrosion ◽  
High Chromium ◽  
Temperature Performance ◽  
Equivalent Number ◽  
Nitrogen Contents

Abstract The high chromium, molybdenum, and nitrogen contents of alloy Uranus B25 (also referred to as UR B25) and its pitting resistance equivalent number (PREN) of >=42 explain why the grade is very resistant to localized corrosion even in acidified oxidizing environments. The alloy has also been used for seawater applications. This datasheet provides information on composition, physical properties, microstructure, hardness, elasticity, tensile properties, and shear strength as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as heat treating and joining. Filing Code: SS-907. Producer or source: Industeel USA, LLC.

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