scholarly journals Kinetics of Zinc Corrosion in Concrete as a Function of Water and Oxygen Availability

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2786
Author(s):  
Petr Pokorný ◽  
Milan Kouřil ◽  
Vojtěch Kučera
Keyword(s):  
Corrosion Rate ◽  
Electrical Resistance ◽  
High Sensitivity ◽  
Active State ◽  
Galvanized Steel ◽  
Zinc Surface ◽  
Corrosion Kinetics ◽  
Zinc Corrosion ◽  
Kinetics Of ◽  
Oxidation Agent

This paper studies the effect of water as an oxidation agent and also of oxygen on zinc corrosion kinetics in active state in concrete, using high-sensitivity electrical resistance sensors. It was proven that zinc corrosion in active state is strongly affected by the presence of water at its surface. Zinc corrosion in real concrete in the absence of water can be misinterpreted as salt passivity. The presence of oxygen results in an increase of zinc corrosion rate, however at pH 12.6, passivity can occur. It was verified that corrosion products consisting primarily of Ca[Zn(OH)3]2·2H2O cannot effectively passivate zinc surface in concrete, even after 1800 h of exposure and zinc, or hot-dip galvanized steel can corrode at an unacceptable corrosion rate (more than 4 µm·a−1).

Effect of Solution Heat Treatment on Corrosion Kinetics Of Zirconium in 20 Percent Hydrochloric Acid At High Temperature and Pressure

CORROSION ◽  
1963 ◽  
Vol 19 (5) ◽  
pp. 169t-179t ◽  
Author(s):  
WILLIAM E. KUHN
Keyword(s):  
Heat Treatment ◽  
Hydrochloric Acid ◽  
Corrosion Rate ◽  
Solution Heat Treatment ◽  
Solution Treatment ◽  
Water Quenching ◽  
Precipitate Phase ◽  
Corrosion Rates ◽  
Corrosion Kinetics ◽  
Kinetics Of

Abstract An investigation has been made of the influence of amount and distribution of precipitate phase on the corrosion kinetics of “low purity” zirconium in 20 percent hydrochloric acid at 200 C. It was found that minimum corrosion rates, coincident with minimum values of activation energy and frequency factor in the Arrhenius relationship, were obtained by solution heat treatment at 700 C followed by water quenching. Such heat treatment gave a corrosion rate equivalent to that of alpha annealed iodide zirconium. A maximum corrosion rate was obtained by a beta solution treatment at 890 C followed by water quenching, whereas beta solution treatment at 1000 C gave sharply reduced corrosion rates. Nature of distribution of the precipitate phase profoundly influenced corrosion rate. A discontinuous pattern of intergranular and transgranular globular particles was substantially less deleterious than the same amount of impurity phase finely disseminated throughout the microstructure. The results of the investigation are discussed in terms of the possible roles of chlorine and hydroxyl ions in the corrosion mechanism. Relative effects on corrosion kinetics of statistical distributions of active sites (each characteristic of lattice configurations produced by lattice defects, solute atoms and precipitation phenomena) are also considered.

Thermal Decomposition of Li(NTO)·2H2O and Na(NTO)·H2O (NTO = Anion of 3-Nitro-1,2,4-triazol-5-one): Kinetics Derived from T-jump/FTIR Spectroscopy

2006 ◽  
Vol 71 (1) ◽  
pp. 129-137 ◽  
Author(s):  
Yuanhua Sun ◽  
Tonglai Zhang ◽  
Jianguo Zhang ◽  
Xiaojing Qiao ◽  
Li Yang ◽  
...  
Keyword(s):  
Ftir Spectroscopy ◽  
Energetic Material ◽  
Burning Surface ◽  
High Sensitivity ◽  
Control Voltage ◽  
Differential Scanning Colorimetry ◽  
Voltage Trace ◽  
Dsc Method ◽  
Phase Chemistry ◽  
Kinetics Of

A "snapshot" simulation of the surface reaction zone is captured by a thin film of material heated rapidly to temperatures characteristic of the burning surface by using the T-jump/FTIR spectroscopy. The time-to-exotherm (tx) kinetics method derived from the control voltage trace of the Pt filament can be introduced to resolve the kinetics of an energetic material owing to its high sensitivity to the thermochemical reactions. The kinetic parameters of the two title compounds are determined under different pressures. The results show that Li(NTO)·2H2O and Na(NTO)·H2O (NTO = anion of 3-nitro-1,2,4-triazol-5-one) exhibit weak pressure dependence, their decomposition is dominated by the condensed phase chemistry irrespective of the pressure in the 0.1-1.1 MPa range. The values of Ea determined here are smaller than those given by a traditional non-isothermal differential scanning colorimetry (DSC) method, which might be resembled as the surface of explosion more closely and enabled the pyrolysis surface to be incorporated into models of steady and possibly unsteady combustion. The kinetics can also be successfully used to understand the behavior of the energetic material in practical combustion problems.

Corrosion kinetics of Al2O3+ZrO2·5CaO coatings applied on gray cast iron substrate

2017 ◽  
Vol 43 (17) ◽  
pp. 15708-15713 ◽  
Author(s):  
Abhinav ◽  
N. Krishnamurthy ◽  
Ranjana Jain
Keyword(s):  
Cast Iron ◽  
Gray Cast Iron ◽  
Gray Cast ◽  
Corrosion Kinetics ◽  
Kinetics Of

High-Temperature Corrosion of Ni3Al+ 2.9%Cr Alloy in Ar-0.2%SO2 Gas

2018 ◽  
Vol 775 ◽  
pp. 441-447
Author(s):  
Dong Bok Lee ◽  
Min Jung Kim ◽  
Gyu Chul Cho ◽  
Soon Young Park ◽  
Poonam Yadav
Keyword(s):  
High Temperature ◽  
Corrosion Rate ◽  
Corrosion Behavior ◽  
Kirkendall Effect ◽  
High Temperature Corrosion ◽  
Scale Spallation ◽  
Corrosion Tests ◽  
Cooling Period ◽  
Corrosion Kinetics ◽  
Period 2

The high-temperature corrosion behavior of Ni3Al+2.9 wt% Cr alloy was studied in SO2-containing environment. Corrosion tests were carried out at 900, 1000, and 1100 °C for 100 h in atmospheric Ar-0.2% SO2 gas. The alloy corroded relatively slowly due mainly to formation of Al2O3 in the scale. Its corrosion kinetics deviated from the parabolic corrosion rate law to a certain extent owing to ensuing scale spallation. This was attributed to (1) stress generated during scaling and the subsequent cooling period, (2) voids that formed due to the Kirkendall effect, and (3) incorporation of sulfur in the scale. The scale that formed after corrosion at 900 °C consisted of the outer NiO scale, middle NiAl2O4 scale, and inner Al2O3 scale. The increased corrosion rate at 1000 and 1100 °C led to formation of the outer NiO scale, and inner Al2O3 scale.

The steady-State corrosion kinetics of two-phase binary alloys forming the most-stable oxide

1996 ◽  
Vol 46 (5-6) ◽  
pp. 383-398 ◽  
Author(s):  
F. Gesmundo ◽  
P. Castello ◽  
F. Viani
Keyword(s):  
Steady State ◽  
Binary Alloys ◽  
Two Phase ◽  
Stable Oxide ◽  
Corrosion Kinetics ◽  
Kinetics Of

Strain Enhanced Corrosion in the Iron-Caustic System

CORROSION ◽  
1976 ◽  
Vol 32 (9) ◽  
pp. 353-357 ◽  
Author(s):  
RONALD B. DIEGLE ◽  
DAVID A. VERMILYEA
Keyword(s):  
Steady State ◽  
Corrosion Rate ◽  
Strain Rate ◽  
Electrolyte Concentration ◽  
Applied Strain ◽  
Crack Advance ◽  
Film Rupture ◽  
Applied Strain Rate ◽  
Corrosion Of Iron ◽  
Kinetics Of

Abstract Straining electrode experiments were performed to investigate the nature of strain enhanced corrosion of iron in caustic electrolyte. The strain enhanced corrosion rate was generally linearly dependent on applied strain rate, and its potential dependence paralleled that of steady-state polarization behavior on non-straining electrodes. Data was presented as ratios, in which is the corrosion rate in cm/s and is the corresponding strain rate. This ratio, which was shown in a previously published theory to be numerically equal to the crack advance per film rupture event during film rupture SCC, depended on electrochemical variables such as electrolyte concentration and temperature in a manner similar to the kinetics of caustic cracking. Conditions which are known to be marginal in producing caustic cracking resulted in values for of about 10−7 cm, in excellent agreement with a previously developed theory. It was concluded that strain enhanced corrosion in this system results from repetitive film rupture and repair during straining.

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