scholarly journals Effect of Chemistry Variations of Wrought N06022 Plates on the Repassivation Potential in 1 M NaCl at 90°C

2008 ◽  
Author(s):  
Kevin G. Mon ◽  
Raul B. Rebak
Keyword(s):  
Chemical Composition ◽  
Potentiodynamic Polarization ◽  
Heat Treating ◽  
Weight Percent ◽  
Nacl Solution ◽  
Nickel Chromium ◽  
Repassivation Potential ◽  
Heat Treated ◽  
Alloy 22 ◽  
Cyclic Potentiodynamic Polarization

ASTM standard B 575 provides the requirements for the chemical composition of Nickel-Chromium-Molybdenum (Ni-Cr-Mo) alloys such as Alloy 22 (N06022). The composition of each element is given in a range (e.g., the lowest content of Mo is specified as 12.5 weight percent and the highest as 14.5 weight percent. It is important to determine the dependence of Alloy 22 electrochemical behavior on the composition of the alloying elements as they vary from the lowest to the highest end of the ranges specified in ASTM B 575 standard. Seven heats of Alloy 22 plate were melted and processed. The plates were tested in the mill annealed (MA) and solution heat treated (SHT) condition. Cyclic potentiodynamic polarization tests were performed in 1 M NaCl solution at 90°C. Results show no influence of Alloy 22 chemistry variations or heat treating on the measured repassivation potential.

Experiment Investigation for Design on the Sensitization-Dependent Passivation Characteristics of AL-6XN in 3.5% NaCl Solution

2021 ◽  
Vol 21 (7) ◽  
pp. 3984-3988
Author(s):  
Kwang-Hu Jung ◽  
Seong-Jong Kim
Keyword(s):  
Heat Treatment ◽  
Potentiodynamic Polarization ◽  
Treatment Time ◽  
Test Methods ◽  
Double Loop ◽  
Nacl Solution ◽  
Heat Treated ◽  
Cyclic Potentiodynamic Polarization ◽  
Degree Of Sensitization ◽  
Characteristic Values

The sensitization and passivation characteristics of AL-6XN heat-treated for up to 24 h at 800 °C were evaluated through double loop electrochemical potentiodynamic reactivation (2 M H2SO4 + 0.01 M KSCN +2 M NaCl solution) and cyclic potentiodynamic polarization (3.5% NaCl solution) test methods. Furthermore, the dependence between the characteristic values (Epit, Erep, and degree of sensitization) was discussed. The σ phase was precipitated at the intergranular and intragranular in AL-6XN at 800 °C. When the heat treatment time exceeded 1 hour, AL-6XN occurred rapid sensitization due to the precipitation of σ phase. In a 3.5% NaCl solution, the passivation characteristics of AL-6XN with sensitivity were very poor and depended much on the degree of sensitization.

scholarly journals Repassivation Potential of Alloy 22 in Chloride plus Nitrate Solutions using the Potentiodynamic-Galvanostatic-Potentiostatic Method

2006 ◽  
Vol 985 ◽  
Author(s):  
Kenneth J. Evans ◽  
Raul B. Rebak
Keyword(s):  
Sodium Chloride ◽  
Potentiodynamic Polarization ◽  
Crevice Corrosion ◽  
Potassium Nitrate ◽  
Potentiostatic Method ◽  
Repassivation Potential ◽  
Alloy 22 ◽  
Cyclic Potentiodynamic Polarization ◽  
Nitrate Solutions

AbstractIn general, the susceptibility of Alloy 22 to suffer crevice corrosion is measured using the Cyclic Potentiodynamic Polarization (CPP) technique. This is a fast technique that gives rather accurate and reproducible values of repassivation potential (ER1) in most cases. In the fringes of susceptibility, when the environment is not highly aggressive, the values of repassivation potential using the CPP technique may not be highly reproducible, especially because the technique is fast and because transpassive corrosion may influence or mask the nucleation and propagation of crevice corrosion. To circumvent this, the repassivation potential of Alloy 22 was measured using a slower method that combines Potentiodynamic-Galvanostatic-Potentiostatic steps (called here the Tsujikawa-Hisamatsu Electrochemical or THE method). The THE method applies the charge to the specimen in a more controlled way, which may give more reproducible repassivation potential values, especially when the environment is not aggressive. The values of repassivation potential of Alloy 22 in sodium chloride plus potassium nitrate solutions were measured using the THE and CPP methods. Results show that both methods yield similar values of repassivation potential, especially under aggressive conditions.

scholarly journals Effect of Small Variation in the Composition of Plates and Weld Filler Wires on the General Corrosion Rate of Ni-Cr-Mo Alloys

2005 ◽  
Author(s):  
David V. Fix ◽  
John C. Estill ◽  
Rau´l B. Rebak
Keyword(s):  
Corrosion Rate ◽  
Filler Metal ◽  
Small Variation ◽  
Weight Percent ◽  
General Corrosion ◽  
Nickel Chromium ◽  
Immersion Corrosion ◽  
Heat Treated ◽  
Alloy 22 ◽  
G 28

The ASTM standard B 575 provides the requirements for the chemical composition of Nickel-Chromium-Molybdenum (Ni-Cr-Mo) alloys such as Alloy 22 (N06022) and Alloy 686 (N06686). The compositions of each element are given in a range. For example, the content of Mo is specified from 12.5 to 14.5 weight percent for Alloy 22 and from 15.0 to 17.0 weight percent for Alloy 686. It was important to determine how the corrosion rate of welded plates of Alloy 22 using Alloy 686 weld filler metal would change if heats of these alloys were prepared using several variations in the composition of the elements even though still in the range specified in B 575. All the material used in this report were especially prepared at Allegheny Ludlum Co. Seven heats of plate were welded with seven heats of wire. Immersion corrosion tests were conducted in a boiling solution of sulfuric acid plus ferric sulfate (ASTM G 28 A) using both as-welded (ASW) coupons and solution heat-treated (SHT) coupons. Results show that the corrosion rate was not affected by the chemistry of the materials within the range of the standards.

scholarly journals Effect of Chemistry Variations in Plate and Weld Filler Metal on the Corrosion Performance of Ni-Cr-Mo Alloys

2006 ◽  
Author(s):  
David V. Fix ◽  
Rau´l B. Rebak
Keyword(s):  
Sulfuric Acid ◽  
Corrosion Rate ◽  
Filler Metal ◽  
Weight Percent ◽  
Corrosion Performance ◽  
Nickel Chromium ◽  
Immersion Corrosion ◽  
Heat Treated ◽  
Alloy 22 ◽  
G 28

The ASTM standard B 575 provides the requirements for the chemical composition of Nickel-Chromium-Molybdenum (Ni-Cr-Mo) alloys such as Alloy 22 (N06022) and Alloy 686 (N06686). The compositions of each element are given in a range. For example, the content of Mo is specified from 12.5 to 14.5 weight percent for Alloy 22 and from 15.0 to 17.0 weight percent for Alloy 686. It was important to determine how the corrosion rate of welded plates of Alloy 22 using Alloy 686 weld filler metal would change if heats of these alloys were prepared using several variations in the composition of the elements even though still in the range specified in B 575. All the material used in this report were especially prepared at Allegheny Ludlum Co. Seven heats of plate were welded with seven heats of wire. Immersion corrosion tests were conducted in a boiling solution of sulfuric acid plus ferric sulfate (ASTM G 28 A) using both as-welded (ASW) coupons and solution heat-treated (SHT) coupons. Results show that the corrosion rate was not affected by the chemistry of the materials in the range of the standards.

NICROFER 5520 Co

Alloy Digest ◽  
1995 ◽  
Vol 44 (3) ◽  
Keyword(s):  
High Temperature ◽  
Chemical Composition ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Temperatures ◽  
Heat Treating ◽  
High Temperature Corrosion ◽  
Creep Properties ◽  
Nickel Chromium ◽  
Temperature Performance

Abstract NICROFER 5520 Co is a nickel-chromium-cobalt-molybdenum alloy with excellent strength and creep properties up to high temperatures. Due to its balanced chemical composition the alloy shows outstanding resistance to high temperature corrosion in the form of oxidation and carburization. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-480. Producer or source: VDM Technologies Corporation.

AISI 9840

Alloy Digest ◽  
1957 ◽  
Vol 6 (3) ◽  
Keyword(s):  
Fracture Toughness ◽  
Heat Treating ◽  
Good Combination ◽  
Nickel Chromium ◽  
Steel Mills ◽  
Treated Condition ◽  
Heat Treated ◽  
Molybdenum Steel ◽  
Heat Treated Condition ◽  
Lower Nickel

Abstract AISI 9840 is a nickel-chromium-molybdenum steel very similar to AISI 4340 with lower nickel and slightly higher manganese. In the heat treated condition it has good combination of strength, fatigue resistance, toughness and wear resistance. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness. It also includes information on forming, heat treating, machining, and joining. Filing Code: SA-55. Producer or source: Alloy steel mills and foundries.

XPS Studies on Composite TiO2-SiO2 Thin Films Deposited on Metal Substrate by Sol-Gel

2005 ◽  
Vol 475-479 ◽  
pp. 1647-1650 ◽  
Author(s):  
Xin Gang Yu ◽  
Hong Wen Ma ◽  
Fei Long ◽  
Hui Feng Zhao ◽  
Wenrue Bi ◽  
...  
Keyword(s):  
Thin Films ◽  
Chemical Composition ◽  
Photoelectron Spectroscopy ◽  
Substrate Surface ◽  
Sol Gel ◽  
Stable State ◽  
Weight Percent ◽  
Metal Substrate ◽  
Metal Substrates ◽  
Heat Treated

Through X-ray photoelectron spectroscopy, by the aid of Ar+ sputtering, chemical composition and the valence state of elements on surface and at depth of TiO2-SiO2 thin films and metal substrates have been studied. Results show that: on surface, elements of Cr, Mn, Ti, Fe exist in the form of their respective stable state, but Si is unstable and exhibits stoichiometrical disturbance when heat treated at 800°C; at depth, after sputtering for 5 minutes and 17 minutes, elements of Cr, Mn, Ti and Ni exist in the form of their respective stable state, but Si and Fe are unstable and exhibit stoichiometrical disturbances; at depth, after sputtering for 57 minutes, all of the Cr, Mn, Ti, Si, Ni and Fe exist in the form of their respective stable state. Results of chemical composition and their content by weight percent of TiO2-SiO2 thin films and metal substrates reveal that: Fe, Cr, and Mn diffuse from metal substrates to the thin films in scale; Ni diffuses few and Si collects to the metal substrate surface

scholarly journals Effect of Sr and Ti Addition on the Corrosion Behaviour of Al-7Si-0.3Mg Alloy

2017 ◽  
Vol 17 (2) ◽  
pp. 125-130 ◽  
Author(s):  
M. Uludağ ◽  
M. Kocabaş ◽  
D. Dışpınar ◽  
R. Çetin ◽  
N. Cansever
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Potentiodynamic Polarization ◽  
Corrosion Test ◽  
Corrosion Behaviour ◽  
Tensile Tests ◽  
Nacl Solution ◽  
Cyclic Potentiodynamic Polarization ◽  
Ti Addition

AbstractIn the present study, the corrosion behaviour of A356 (Al-7Si-0.3Mg) alloy in 3.5% NaCl solution has been evaluated using cyclic/potentiodynamic polarization tests. The alloy was provided in the unmodified form and it was then modified with AlTi5B1 for grain refinement and with AlSr15 for Si modifications. These modifications yield to better mechanical properties. Tensile tests were performed. In addition, bifilm index and SDAS values were calculated and microstructure of the samples was investigated. As a result of the corrosion test, the Ecorr values for all conditions were determined approximately equal, and the samples were pitted rapidly. The degassing of the melt decreased the bifilm index (i.e. higher melt quality) and thereby the corrosion resistance was increased. The lowest corrosion rate was founded at degassing and as-received condition (3.9x10-3mm/year). However, additive elements do not show the effect which degassing process shows.

scholarly journals Electrochemical Investigation of Corrosion Behavior Heat Treated Al-6Si-0.5Mg-xCu (x = 0, 0.5, 1, 2, and 4 wt%) Alloys

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
A. Hossain ◽  
F. Gulshan ◽  
A. S. W. Kurny
Keyword(s):  
Charge Transfer ◽  
Potentiodynamic Polarization ◽  
Corrosion Potential ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Nacl Solution ◽  
Transfer Resistance ◽  
Cu Content ◽  
Cu Alloy ◽  
Heat Treated

The corrosion behaviour of heat treated Al-6Si-0.5Mg-xCu (x=0.5, 1, 2, and 4 wt%) alloys in 0.1 M NaCl solution was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The potentiodynamic polarization curves reveal that 2 wt% Cu (Alloy-4) and 4 wt% Cu (Alloy-5) content alloys are more prone to corrosion than the other alloys investigated. But the EIS test results showed that charge transfer resistance (Rct) increases with increasing Cu content into Al-6Si-0.5Mg. Maximum charge transfer resistance (Rct) is reported with the addition of 2 wt% Cu and minimumRctvalue is for 4 wt% Cu content Al-6Si-0.5Mg alloy. Due to additions of Cu into Al-6Si-0.5Mg alloy, the magnitudes of open circuit potential (OCP), corrosion potential (Ecorr), and pitting corrosion potential (Epit) in NaCl solution were shifted to the more noble direction.

Determination of Crevice Corrosion Susceptibility of Alloy 22 Using Different Electrochemical Techniques

2010 ◽  
Vol 1265 ◽  
Author(s):  
Mauricio Rincon Ortiz ◽  
Martín A. Rodríguez ◽  
Ricardo M. Carranza ◽  
Raul B. Rebak
Keyword(s):  
Crevice Corrosion ◽  
Electrochemical Techniques ◽  
Localized Corrosion ◽  
Repassivation Potential ◽  
Alloy 22 ◽  
Cyclic Potentiodynamic Polarization ◽  
Corrosion Susceptibility ◽  
High Level Nuclear Waste ◽  
High Level

AbstractAlloy 22 belongs to the Ni-Cr-Mo family and it is highly resistant to general and localized corrosion. It may suffer crevice corrosion in aggressive environmental conditions. This alloy has been considered as a corrosion-resistant barrier for high-level nuclear waste containers. It is assumed that localized corrosion may occurs when the corrosion potential (ECORR) is equal or higher than the crevice corrosion repassivation potential (ER,CREV). The latter is measured by means of different electrochemical techniques using artificially creviced specimens. These techniques include cyclic potentiodynamic polarization (CPP) curves, Tsujikawa-Hisamatsu electrochemical (THE) method or other non-standard methods, such as the PD-GS-PD technique.The aim of the present work was to determine reliable critical or protection potentials for crevice corrosion of Alloy 22 in pure chloride solutions at 90°C. Conservative methodologies (which include extended potentiostatic steps) were applied for determining protection potentials below which crevice corrosion cannot initiate and propagate. Results from PD-GS-PD technique were compared with those from these methodologies in order to assess their reliability. Results from the CPP and the THE methods were also considered for comparison. The repassivation potential resulting from the PD-GS-PD technique was conservative and reproducible, and it did not depend on the amount of previous crevice corrosion propagation.

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