Quantitative Analysis Methods of Chloride Deposition on Silver for Atmospheric Corrosion Monitoring in South Korea

CORROSION ◽  
10.5006/3622 ◽  
2020 ◽  
Author(s):  
Wonjun Choi ◽  
Dooyoul Lee ◽  
Chi Bum Bahn
Keyword(s):  
South Korea ◽  
Surface Analysis ◽  
Deposition Rate ◽  
Atmospheric Corrosion ◽  
Reduction Method ◽  
Alternative Methods ◽  
Corrosion Monitoring ◽  
X Ray ◽  
Analysis Tools ◽  
Chloride Deposition

The chloride deposition rate is one of critical factors affecting the atmospheric corrosion of metals, which can be monitored by exposing Ag specimens and analyzing their surfaces using various ways. Although a coulometric reduction method can provide an absolute chloride deposition rate, new and alternative methods can be pursed, i.e., methods using typical surface analysis tools (scanning electron microscopy-energy dispersive X-ray spectroscopy, SEM-EDS; X-ray diffraction, XRD; and X-ray photoelectron spectroscopy, XPS). Since the surface analysis tools can only provide relative values, a correlation between the coulometric reduction and surface analyses should be developed. To develop the correlation between them, Ag specimens were prepared by exposing them to the atmosphere at 12 locations in South Korea for one year. Surface analysis of retrieved Ag specimens yielded correlations for the chloride deposition rates between the coulometric reduction method and typical surface analysis tools. Each correlation showed a fairly linear relationship, especially ones obtained from SEM-EDS and XPS. The developed correlations can be used when estimating the chloride deposition rate by using surface analysis tools as an alternative to the coulometric reduction method.

scholarly journals Corrosion of Copper in Unpolluted Chloride-Rich Atmospheres

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 866 ◽  
Author(s):  
Patricia Lopesino ◽  
Jenifer Alcántara ◽  
Daniel de la Fuente ◽  
Belén Chico ◽  
José Jiménez ◽  
...  
Keyword(s):  
Atmospheric Corrosion ◽  
Product Layer ◽  
Corrosion Products ◽  
X Ray Diffraction ◽  
Deposition Rates ◽  
X Ray ◽  
Corrosion Product Layer ◽  
Salinity Levels ◽  
Notable Increase ◽  
Chloride Deposition

The atmospheric corrosion of copper in pure coastal atmospheres has not been extensively studied. This paper presents the results of research carried out in pure coastal atmospheres with annual chloride deposition rates of between 110–1640 mg/m2·d. Copper specimens (99.99 wt % Cu) were exposed for 3, 6, 9, and 12 months at six testing stations located at different distances from the seashore. Tests were performed to determine the copper corrosion rate, the surface area coated with corrosion products, and the evolution of both magnitudes with exposure time. Conventional and grazing X-ray diffraction techniques were used to analyze the corrosion products formed—cuprite and the polymorphs botallackite, atacamite, and clinoatacamite—and their presence through the patina thickness, while scanning electron microscopy/energy dispersive X-ray spectrometry was employed to study the morphology of the resulting corrosion layers. The most relevant findings are a notable increase in atacamite and clinoatacamite formation at higher atmospheric salinity levels and longer exposure times, and the flaking-off of the corrosion product layer formed in the marine atmospheres with the highest chloride deposition rates.

scholarly journals Optical Constant and Conformality Analysis of SiO2 Thin Films Deposited on Linear Array Microstructure Substrate by PECVD

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 510
Author(s):  
Yongqiang Pan ◽  
Huan Liu ◽  
Zhuoman Wang ◽  
Jinmei Jia ◽  
Jijie Zhao
Keyword(s):  
Thin Films ◽  
Film Thickness ◽  
Deposition Rate ◽  
Optical Constant ◽  
Photoelectron Spectroscopy ◽  
Linear Array ◽  
Chemical Vapor ◽  
Rf Plasma ◽  
X Ray ◽  
Sio2 Thin Film

SiO2 thin films are deposited by radio frequency (RF) plasma-enhanced chemical vapor deposition (PECVD) technique using SiH4 and N2O as precursor gases. The stoichiometry of SiO2 thin films is determined by the X-ray photoelectron spectroscopy (XPS), and the optical constant n and k are obtained by using variable angle spectroscopic ellipsometer (VASE) in the spectral range 380–1600 nm. The refractive index and extinction coefficient of the deposited SiO2 thin films at 500 nm are 1.464 and 0.0069, respectively. The deposition rate of SiO2 thin films is controlled by changing the reaction pressure. The effects of deposition rate, film thickness, and microstructure size on the conformality of SiO2 thin films are studied. The conformality of SiO2 thin films increases from 0.68 to 0.91, with the increase of deposition rate of the SiO2 thin film from 20.84 to 41.92 nm/min. The conformality of SiO2 thin films decreases with the increase of film thickness, and the higher the step height, the smaller the conformality of SiO2 thin films.

scholarly journals Chemical, electrochemical, thermodynamic and adsorption study of EN8 dual-phase steel with ferrite-martensite structure in 0.5 M H2SO4 using pectin as inhibitor

2021 ◽  
Author(s):  
P. R. Prabhu ◽  
Pavan Hiremath ◽  
Deepa Prabhu ◽  
M. C. Gowrishankar ◽  
B. M. Gurumurthy
Keyword(s):  
Weight Loss ◽  
Adsorption Isotherm ◽  
Surface Analysis ◽  
Potentiodynamic Polarization ◽  
Dual Phase Steel ◽  
Inhibition Efficiency ◽  
Dual Phase ◽  
X Ray ◽  
Enthalpy And Entropy ◽  
Martensite Structure

AbstractThis paper presents the corrosion and inhibition behavior of heat-treated EN8 dual-phase steel with ferrite-martensite structure with pectin in 0.5 M sulphuric acid. The corrosion studies were performed using the weight loss method, electrochemical techniques such as potentiodynamic polarization measurements, and impedance spectroscopy. The study was done at different concentrations of pectin in the temperature range of 40 to 70 °C and immersion time of 1, 3, 5, and 7 h. The results showed that the inhibition performance of pectin has enhanced with an increase in pectin concentration and decreased with the temperature and time of exposure. From the weight loss study, highest inhibition efficiency of 76.43% was achieved at 5.0 g/L at 1 h of exposure at 40 °C. The maximum inhibition efficiency of 62% was obtained with 5.0 g/L of pectin at 40 °C by potentiodynamic polarization method. The energy, enthalpy, and entropy of activation and also thermodynamic parameters like free energy, enthalpy, and entropy of adsorption were assessed and discussed. Appropriate adsorption isotherm was fit to the obtained experimental outcomes and achieved Langmuir adsorption isotherm to be the best fit and obeyed physical adsorption. Surface analysis: scanning electron microscopy, X-ray diffraction techniques, atomic force microscopy, and energy dispersive X-ray were done with and without the addition of pectin. The metal surface appears to be uniform and smooth in the presence of pectin and adsorption was confirmed by surface analysis.

Evaluation Method for Time-Dependent Corrosion Behavior of Carbon Steel Plate Using Atmospheric Corrosion Monitoring Sensor

2009 ◽  
Vol 417-418 ◽  
pp. 417-420 ◽  
Author(s):  
Shigenobu Kainuma ◽  
Kunihiro Sugitani ◽  
Yoshihiro Ito ◽  
In Tae Kim
Keyword(s):  
Carbon Steel ◽  
Corrosion Behavior ◽  
Atmospheric Corrosion ◽  
Evaluation Method ◽  
Steel Plates ◽  
Time Dependent ◽  
Corrosion Monitoring ◽  
Corrosion Sensor ◽  
Atmospheric Exposure ◽  
Corrosive Environments

The purpose of this research is to propose a method for evaluating the time-dependent corrosion behavior of carbon steel plates using an atmospheric corrosion monitor (ACM) corrosion sensor consisting of a Fe/Ag-galvanic couple. Atmospheric exposure tests were carried out on steel　plates for periods of 6, 12, and 24-months on the island of Okinawa in Japan. The Specimens were mounted on racks at angles of 0, 45 and 90 to the horizontal to obtain corrosion data in various corrosive environments. In addition, the environments of the skyward- and groundward-facing surfaces of the specimens were monitored using ACM sensors. The sensor outputs were recorded during the exposure tests.

Surface Analysis by X-ray Photoelectron Spectroscopy of Sol−Gel Silica Modified with Covalently Bound Peptides

2007 ◽  
Vol 111 (40) ◽  
pp. 11850-11857 ◽  
Author(s):  
Sabrina S. Jedlicka ◽  
Jenna L. Rickus ◽  
Dmitry Y. Zemlyanov
Keyword(s):  
Surface Analysis ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
X Ray ◽  
Covalently Bound
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