A Study of Zircaloy-2 Corrosion in High Temperature Water Using Ion Beam Methods

CORROSION ◽  
1981 ◽  
Vol 37 (10) ◽  
pp. 575-585 ◽  
Author(s):  
I. S. Woolsey ◽  
J. R. Morris
Keyword(s):  
High Temperature ◽  
Ion Beam ◽  
Short Circuit ◽  
Oxide Surface ◽  
Aqueous Corrosion ◽  
Protective Oxide ◽  
Transport Behavior ◽  
High Temperature Water ◽  
Diffusion Paths ◽  
Temperature Water

Abstract Corrosion experiments have been carried out on Zircaloy-2 specimens in water at 355 C to study the transport of oxygen and hydrogen (as deuterium) in growing corrosion films. The transport behavior was studied by using O18 and deuterium labelled water, and analyzing the corrosion films for these isotopes by the use of ion beam induced nuclear reactions. Analysis for O18 was performed by means of the O18 (p,α)N15 reaction, using incident 850 and 950 keV protons. The analyses for deuterium were made using the D(He3,d)p reaction employing incident 850 and 1300 keV He3 ions, and detecting the scattered α-particles. The composition of the corrosion films was also examined in 2.9 MeV and 3.9 MeV α-particle backscattering experiments. From these studies, it was concluded that the corrosion of Zircaloy-2 in high temperature water occurs predominantly by oxygen diffusion through the corrosion film via grain boundary or similar short circuit diffusion paths, to form fresh oxide at the oxide metal interface. The diffusivity of oxygen through the pre-breakaway films decreased with time as a result of a decrease in the available easy diffusion paths as the oxide aged. This was interpreted as the primary cause of the subparabolic kinetics normally observed prior to the rate transition during high temperature aqueous corrosion of Zircaloy-2. There was also evidence that increasing grain size deeper within thick pre-breakaway films contributes to the decrease in oxygen diffusivity. The oxygen transport behavior in post-breakaway corrosion films indicates that the rate transition results from the generation of new diffusion pathways in previously protective oxide. Unexpectedly high concentrations of deuterium were observed in the corrosion films. These were about 4.5% atomic at the oxide surface, falling to 1 % atomic at depths between 1 and 1.5 μm. The deuterium was also found to be highly mobile within the oxide, much more so than oxygen.

Effect of Temperature and Dissolved Oxygen on the Corrosion Behavior of Carbon Steel in High-Temperature Water

CORROSION ◽  
1991 ◽  
Vol 47 (7) ◽  
pp. 500-508 ◽  
Author(s):  
K. Mabuchi ◽  
Y. Horn ◽  
H. Takahashi ◽  
M. Nagayama
Keyword(s):  
High Temperature ◽  
Carbon Steel ◽  
Oxide Film ◽  
Dissolved Oxygen ◽  
Corrosion Behavior ◽  
Effect Of Temperature ◽  
Oxide Surface ◽  
X Ray ◽  
High Temperature Water ◽  
Temperature Water

Abstract The corrosion behavior of carbon steel in high-temperature water, and the structure and composition of the oxide film were examined as functions of dissolved oxygen concentration (DO), temperature (T), and corrosion time (t). The total amount of iron corroded (WT) was differentiated into the amounts of iron ions in the oxide (WF) and dissolved into the water (WD). The total rate of corrosion (rT), the rate of iron dissolution (rD), and the rate of accumulation of iron in the oxide (rF) were obtained by differentiating the time variations in WT, WF, and WD. The structure and composition of the oxide film were examined by x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and transmission and scanning electron microscopy. In general, rT increases with increasing DO and T, rD shows T- and DO-dependent minimum, and there is serious localized corrosion at high DO above 500 ppb. Oxide films consist of magnetite except at T=60°C, DO=50 to 200 ppb where a thin layer of hydrous ferric oxide is formed. At DO=500 ppb , the outermost part of the magnetite changes into γ-Fe2O3, and above DO=1.0 ppm, appreciable amounts of α-Fe2O3 cover the magnetite oxide layer. The rT and rD values are not related to the presence of αFe2O3 or Fe3O4 in the surface structure of the oxide, but clearly decrease as the OH−/Fe mole ratio at the oxide surface increases. The mechanism determining the corrosion rate changes is discussed.

Investigation of the Development Processes of Self-Organizing, Protective Oxide Scales and Wear Resistant Surface Layers on the Fe-44%Cr-1%Ni-4%Al-0.3%La Alloy

2008 ◽  
Vol 595-598 ◽  
pp. 833-840 ◽  
Author(s):  
Olga Tsurtsumia ◽  
Elguja Kutelia ◽  
Boris Bulia ◽  
Omar Mikadze
Keyword(s):  
Surface Layer ◽  
High Temperature ◽  
Short Circuit ◽  
Cold Work ◽  
Metallic Matrix ◽  
Nano Particles ◽  
Oxide Surface ◽  
Protective Oxide ◽  
Complex Investigation ◽  
Self Organizing

Using the methods of scanning electron microscopy (SEM), Auger electron spectrometry (AES), fast electron diffraction (FED) in the “on reflection” regime and wavelength dispersive spectrometry (WDS) a complex investigation of the hierarchical sequence of amorphous Beilby layer formation has been studied due to the self-organizing dissipative processes, associated with extensive cold work, on the surface of an Fe-Cr-Ni-Al-La alloy, with high (>40%) chromium content. It was established that, the surface layer (≤1μm thickness) of the mechanically polished specimen of Fe-44%Cr-1%Ni-4%Al-0.3%La alloy consists of the amorphous Beilby layer and that its adjacent matrix layer, crushed due to the plastic deformation, formed an entropy “excited” functional system, which at the temperature of 1200°C in laboratory atmosphere permits the formation of an oxide surface layer with a micro-wrinkles modulated structure of uniform thickness, in the form of mixture of nanocrystallites (100÷500nm) made of oxides of atoms constituting the basic metallic matrix. Beneath this layer a thin alumina scale is observed to form. Increasing the oxidation temperature causes the regrowth of nanocrystallites and also the recrystallization processes, accompanied by solid-phase reactions between oxide nano-particles. This leads to scale delamination at the superficial oxide thin uniform alumina layer interface. The Al2O3 layer is characterized by high adherence with metallic substrate and provides protective features against both high temperature (1200°C) oxidation of the matrix and resistance to abrasion. By the pretreatment at 1200°C of the investigated alloy’s surface modified specimens, there forms a low thickness (several microns) scale which has ultra fine graininess (~1μ) with no porosity and blocked grain boundaries short-circuit diffusion paths. This gives to the scale the ability to protect the metallic matrix against high temperature gas (and other aggressive environment) corrosion.

Effect of Residual Etchant on the Corrosion Behavior of Zircaloy-2

CORROSION ◽  
1961 ◽  
Vol 17 (12) ◽  
pp. 566t-570t ◽  
Author(s):  
STANLEY KASS
Keyword(s):  
High Temperature ◽  
Corrosion Product ◽  
Corrosion Behavior ◽  
Oxide Films ◽  
Aqueous Corrosion ◽  
High Temperature Water ◽  
Corrosion Film ◽  
Temperature Water

Abstract The aqueous corrosion behavior of Zircaloy-2 surfaces contaminated with reaction product from the HNO3-HF-H2O etchant was studied. Surfaces slightly contaminated with residual etchant exhibit cloudy surfaces and corrode more rapidly than non-contaminated surfaces. The surfaces of coupons severely contaminated exhibit white continuously spalling oxide films in high temperature water. In 750 F steam, however, the corrosion is characterized initially by a spalling corrosion film followed by an adherent corrosion product. 6.3.20, 2.3.6

Microstructure Analysis of Stainless Steel Cladding on Low Alloy Steel Weld in a PWR Safe End Nozzle and Corrosion in High Temperature Water

2017 ◽  
Author(s):  
Qi Xiong ◽  
Zhanpeng Lu ◽  
Junjie Chen ◽  
Xiangkun Ru ◽  
Hongjuan Li ◽  
...  
Keyword(s):  
Stainless Steel ◽  
High Temperature ◽  
Oxide Film ◽  
Alloy Steel ◽  
Ion Beam ◽  
Water Environment ◽  
Low Alloy Steel ◽  
Spinel Oxide ◽  
High Temperature Water ◽  
Temperature Water

The complex microstructures of stainless steel (SS) cladding on low alloy steel (LAS) joint and the corrosion behavior in high temperature water environments were examined. Scanning electron microscopy, focused ion beam, transmission electron microscope and Raman spectroscopy were used. The heat-affected zone (HAZ) in the low alloy steel was mainly comprised of pearlite and ferrite, while the HAZ in the stainless steel was mainly comprised of austenite and ferrite. The HAZ in the low alloy steel was divided into overheated crystal region, complete recrystallization region and incompletely recrystallization region. A decarburization zone in the low alloy steel side and a carbon-enriched zone in the stainless steel side were identified. M23C6 and M7C3 precipitation were observed mainly in carbon-enriched zone. The surfaces of the weld after corrosion in simulated PWR primary water environment at 290 °C were significantly affected by dissolved oxygen. In aerated solution, the oxide film on A508III steel was mainly γ-Fe2O3, which becomes spinel oxide on the 309L/308L cladding. In deaerated solution, the oxide film was mainly Fe3O4 on A508III steel, which was spinel oxide on the 309L/308L cladding.

Structural Imperfections in thin Oxide Films Formed on Some Fe- and Ni-Base Alloys

1970 ◽  
Vol 28 ◽  
pp. 510-511
Author(s):  
L. P. Lemaire ◽  
D. E. Fornwalt ◽  
F. S. Pettit ◽  
B. H. Kear
Keyword(s):  
Oxide Scale ◽  
Oxidation Process ◽  
Short Circuit ◽  
Protective Oxide ◽  
Protective Oxide Scale ◽  
Thin Oxide Films ◽  
Diffusion Paths ◽  
Oxidation Resistant ◽  
Structural Imperfections ◽  
Short Circuit Diffusion

Oxidation resistant alloys depend on the formation of a continuous layer of protective oxide scale during the oxidation process. The initial stages of oxidation of multi-component alloys can be quite complex, since numerous metal oxides can be formed. For oxidation resistance, the composition is adjusted so that selective oxidation occurs of that element whose oxide affords the most protection. Ideally, the protective oxide scale should be i) structurally perfect, so as to avoid short-circuit diffusion paths, and ii) strongly adherent to the alloy substrate, which minimizes spalling in response to thermal cycling. Small concentrations (∼ 0.1%) of certain reactive elements, such as yttrium, markedly improve the adherence of oxide scales in many alloy systems.

scholarly journals The Role of Chromium in Iron-based High-Temperature Water-Gas Shift Catalysts under Industrial Conditions

2021 ◽  
pp. 120465
Author(s):  
M.I. Ariëns ◽  
V. Chlan ◽  
P. Novák ◽  
L.G.A. van de Water ◽  
A.I. Dugulan ◽  
...  
Keyword(s):  
High Temperature ◽  
Water Gas Shift ◽  
High Temperature Water ◽  
Iron Based ◽  
Water Gas ◽  
Temperature Water

Electrophoretic mobility of magnetite particles in high temperature water

2011 ◽  
Vol 66 (18) ◽  
pp. 4029-4035 ◽  
Author(s):  
Sonja Vidojkovic ◽  
Victor Rodriguez-Santiago ◽  
Mark V. Fedkin ◽  
David J. Wesolowski ◽  
Serguei N. Lvov
Keyword(s):  
High Temperature ◽  
Electrophoretic Mobility ◽  
High Temperature Water ◽  
Magnetite Particles ◽  
Temperature Water
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