Anodic Polarization Behavior Of Nickel-Chromium Alloys In Sulfuric Acid Solutions

Myers, James R.; Beck, F. H.; Fontana, Márcio

doi:10.5006/0010-9312-21.9.277

Cited by 42 publications

(14 citation statements)

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“…8a͒. Myers et al found that addition of 9 wt % Cr ͑about 10 atom % Cr͒ markedly reduced the critical current density for passivation and significantly reduced active current densities, 23 consistent with the XANES ͑described above͒ and the electrochemical behavior ͑Fig. 1͒ in this work.…”

Section: Discussionsupporting

confidence: 90%

In Situ X-Ray Absorption Near-Edge Structure Study of the Active and Transpassive Dissolution of Passive Films on Ni and Ni-Cr Alloys in 0.1 M H ₂ SO ₄

Oblonsky¹,

Ryan²

2001

J. Electrochem. Soc.

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The formation, reduction, and dissolution processes of passive films formed on Ni, Ni-9 atom % Cr, and Ni-18 atom % Cr alloys in deaerated pH 2, 0.1 M sulfuric acid were studied using in situ X-ray absorption near-edge structure during potential stepping from passive to cathodic or transpassive potentials. At passive potentials, Ni slowly dissolves from pure Ni and Ni-9 atom % Cr, while Cr from the Ni-9 atom % Cr alloy does not dissolve. At passive potentials, neither Ni nor Cr from the Ni-18 atom % Cr alloy dissolves. Stepping between passive and cathodic potentials results in the loss of Ni and Cr to different extents, depending upon the Cr content. No Ni dissolves from either the Ni or the Ni-Cr alloys when the potential is first stepped from the passive to the cathodic potential. Oxidized Ni is reduced to Ni metal in a solid-state reduction reaction. However, upon stepping the potential back to the passive range, Ni does dissolve, with the amount of Ni lost decreasing as Cr content increases: significant Ni dissolves at 0% Cr, a small amount dissolves at 9 atom % Cr, and almost no Ni dissolves at 18 atom % Cr. In contrast, for both the Ni-Cr alloys, approximately a monolayer of Cr dissolves during the step from passive to cathodic potentials, while no Cr dissolves when the potential is stepped back to the passive range. In pH 2 sulfuric acid, Cr in Ni-Cr alloys is susceptible to reductive dissolution but not active dissolution. Transpassivity was also explored. For pure Ni, transpassive dissolution begins above ϩ0.4 V referenced to mercurous sulfate electrode ͑MSE͒ and becomes rapid above ϩ0.5 V. For the Ni-Cr alloys, transpassive dissolution of both Ni and Cr begins above ϩ0.3 V MSE, becoming rapid at ϩ0.4 V. Although Cr provides protection to Ni from active dissolution and from dissolution at passive potentials, Ni does not protect Cr from dissolution at transpassive potentials.In recent years, in situ X-ray absorption near-edge structure ͑XANES͒ has been used to study the passivation behavior primarily of Fe and Fe-Cr alloys in basic and mildly acidic solutions. These studies have demonstrated that XANES can provide information on the oxidation state of specific species in the passive films, 1-4 the reduction and dissolution of individual film components, 1,2,4 the composition of passive films, 2 and the structure or local environment of components of the passive films. 3,5 This information is obtained while the sample is immersed in a bulk aqueous environment and is under well-defined electrochemical control.In this study, the effect of Cr alloying on Ni in deaerated pH 2, 0.1 M sulfuric acid is explored. First, the passivation, reduction, oxidative, and transpassive dissolution of pure Ni are examined. Then, the changes observed upon alloying with 9 and 18 atom % Cr are presented. The results are interpreted in terms of a percolation model for passivation 6 and are considered more generally in light of the wealth of studies on Ni and Ni-Cr alloys in sulfuric acid. The work presented here is an extension ...

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Section: Discussionsupporting

confidence: 90%

In Situ X-Ray Absorption Near-Edge Structure Study of the Active and Transpassive Dissolution of Passive Films on Ni and Ni-Cr Alloys in 0.1 M H ₂ SO ₄

Oblonsky¹,

Ryan²

2001

J. Electrochem. Soc.

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“…2,3 This enhanced passivity is generally attributed to a higher concentration of Cr(III) in the inner oxide layer than in the substrate alloy 4 due to the growth and defect annealing of a Cr(III) oxide barrier layer at the alloy/oxide interface. X-ray photoelectron spectroscopy (XPS) and scanning-tunneling microscopy (STM) have shown that the passive fi lm (on Cr, Fe-Cr, Fe-Cr-Ni, and Ni-Cr metals and alloys) consists primarily of an inner layer of Cr 2 O 3 and an outer layer of Cr(OH) 3 .…”

Section: Introductionmentioning

confidence: 98%

The open-circuit ennoblement of alloy C-22 and other Ni-Cr-Mo alloys

Lloydis

Noël

Shoesmith

et al. 2005

JOM

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polarization, and electrochemical impedance spectroscopy were employed in the study. The composition of the fi lms formed was determined by x-ray photoelectron spectroscopy and time-of-fl ight secondary ion mass spectrometry. Passive oxide fi lm resistances increase and defect oxide fi lm concentrations decrease as fi lms thicken and chromium and molybdenum segregate to the alloy/oxide and oxide/solution interfaces, respectively. The high-chromium alloys exhibit higher fi lm resistances and lower fi lm defect concentrations consistent with the more positive potentials observed on these alloys. The results show that the observed ennoblement in corrosion potentials with time is coupled to the Cr/Mo segregation process and the suppression of defect injection at the alloy/oxide interface. By all measures, C-22 exhibited the best passive properties.

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“…The impact of Ni concentration in the composition of the steel on the formation and dissolution of the passive layer is usually considered to be insignificant, Ni serving to stabilize the austenitic phase without affecting the corrosion resistance. 31 Based on these results, a structure for the oxide layer of the X1CrNiSi18-15-4 SS is proposed and characterized by its n Cr /n Si molar ratio.…”

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confidence: 99%

Dissolution and Passivation of a Silicon-Rich Austenitic Stainless Steel during Active-Passive Cycles in Sulfuric and Nitric Acid

Laurent

Gruet

Gwinner

et al. 2017

J. Electrochem. Soc.

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The high Si containing X1CrNiSi18-15-4 stainless steel (SS) spontaneously forms a protective oxide film that is mostly composed of mixed chromium and silicon oxides. This film ensures a good durability of the industrial facilities the alloy was designed for, containing very acidic electrolytes such as hot and concentrated nitric acid, HNO 3 , in presence of oxidizing species. In the present work, the chemistry of the oxide formed and the passivation kinetics of the alloy in sulfuric acid, H 2 SO 4 , and for the first time in HNO 3 , were monitored by atomic emission spectroelectrochemistry (AESEC) over successive activation and passivation cycles of the material. X1CrNiSi18-15-4 SS was compared to a low Si containing SS, the X2CrNiN18-10 SS. It was found that a similar quantity and rate of passive film was formed during passivation, and dissolved during activation. Reproducible results were obtained over several active-passive cycles. The excess Cr was correlated with the dissolution rate decay during passivation. The Si/Cr ratio of the passive film was determined by X-ray photoelectron spectroscopy, energy dispersive X-ray spectroscopy (performed using transmission electron microscopy), and AESEC giving similar results within experimental error. The EDX profile suggest that the passive film consists of a Si rich outer and Cr rich inner layer.

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Anodic Polarization Behavior Of Nickel-Chromium Alloys In Sulfuric Acid Solutions

Cited by 42 publications

References 2 publications

In Situ X-Ray Absorption Near-Edge Structure Study of the Active and Transpassive Dissolution of Passive Films on Ni and Ni-Cr Alloys in 0.1 M H ₂ SO ₄

In Situ X-Ray Absorption Near-Edge Structure Study of the Active and Transpassive Dissolution of Passive Films on Ni and Ni-Cr Alloys in 0.1 M H ₂ SO ₄

The open-circuit ennoblement of alloy C-22 and other Ni-Cr-Mo alloys

Dissolution and Passivation of a Silicon-Rich Austenitic Stainless Steel during Active-Passive Cycles in Sulfuric and Nitric Acid

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Anodic Polarization Behavior Of Nickel-Chromium Alloys In Sulfuric Acid Solutions

Cited by 42 publications

References 2 publications

In Situ X-Ray Absorption Near-Edge Structure Study of the Active and Transpassive Dissolution of Passive Films on Ni and Ni-Cr Alloys in 0.1 M H 2 SO 4

In Situ X-Ray Absorption Near-Edge Structure Study of the Active and Transpassive Dissolution of Passive Films on Ni and Ni-Cr Alloys in 0.1 M H 2 SO 4

The open-circuit ennoblement of alloy C-22 and other Ni-Cr-Mo alloys

Dissolution and Passivation of a Silicon-Rich Austenitic Stainless Steel during Active-Passive Cycles in Sulfuric and Nitric Acid

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In Situ X-Ray Absorption Near-Edge Structure Study of the Active and Transpassive Dissolution of Passive Films on Ni and Ni-Cr Alloys in 0.1 M H ₂ SO ₄

In Situ X-Ray Absorption Near-Edge Structure Study of the Active and Transpassive Dissolution of Passive Films on Ni and Ni-Cr Alloys in 0.1 M H ₂ SO ₄