Atmospheric corrosion rates, time-of-wetness and relative humidity

1979 ◽  
Vol 30 (1) ◽  
pp. 38-42 ◽  
Author(s):  
Florian Mansfeld
Keyword(s):  
Relative Humidity ◽  
Atmospheric Corrosion ◽  
Corrosion Rates ◽  
Time Of Wetness

scholarly journals A Field Study of Atmospheric Corrosion of Carbon Steel after Short Exposure in Pelabuhan Ratu, West Java Province, Indonesia

2021 ◽  
Vol 18 (17) ◽  
Author(s):  
Gadang PRIYOTOMO ◽  
Siska PRIFIHARNI ◽  
Lutviasari NURAINI ◽  
Joko TRIWARDONO ◽  
Ahmad ROYANI ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Relative Humidity ◽  
Air Temperature ◽  
Atmospheric Corrosion ◽  
Short Exposure ◽  
Corrosion Attack ◽  
West Java ◽  
Corrosion Rates ◽  
Magnetite Fe3o4 ◽  
Chloride Deposition

The investigation of atmospheric corrosion of mild carbon steel as representative of offshore infrastructure has been carried out in the marine tropical of Pelabuhan Ratu, West Java, Indonesia. They are exposed up to 76 days of periods, and their corrosion rates are determined according to ASTM G1-03. The surface morphology, the elemental compositions and compounds were observed using a scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), respectively.  The environmental parameters of the test site are monitored during exposure, such as air temperature, relative humidity (RH), airborne salinity and dew temperature. Based on the results, the corrosion rates of steels were 2.79 and 2.8 mpy within the 27 and 76 days exposures, respectively. The presence of chloride deposition on the surface of steel can increase the severity of corrosion. Moreover, the detrimental effect of chloride was observed in rust product, which was covered by an oxygen element. The main phases of rust products present were magnetite (Fe3O4) and hematite (α-Fe2O3.H2O). Several cracks were observed in the rust layer, which tended to exfoliate and lose adherence and protectiveness from further corrosion attack. HIGHLIGHTS The presence of chloride deposition on the surface of steel can increase the severity of corrosion. The severity of corrosion attack mainly depends on the exposure time and some climatic parameters, such as relative humidity (RH), air temperature and chloride airborne. The uniform distribution of the chloride tends to increase the production of ferrous chloride in high RH condition and the aqueous layer deposited on carbon steel. There are two phases on corroded carbon steel such as hematite (α-Fe2O3.H2O) and Magnetite (Fe3O4) after exposure GRAPHICAL ABSTRACT

scholarly journals Atmospheric corrosivity in Bogota as a very high-altitude metropolis questions international standards

DYNA ◽  
2015 ◽  
Vol 82 (190) ◽  
pp. 128-137 ◽  
Author(s):  
John Fredy Ríos Rojas ◽  
Diego Escobar Ocampo ◽  
Edwin Arbey Hernández García ◽  
Carlos Enrique Arroyave Posada
Keyword(s):  
Relative Humidity ◽  
Atmospheric Corrosion ◽  
Meteorological Parameters ◽  
International Standards ◽  
Corrosion Rates ◽  
Pollution Problem ◽  
One Year ◽  
The City ◽  
Very High ◽  
So2 Concentration

<p>This paper presents the first systematic atmospheric corrosion assessment in Bogota. Main facts about the study are related with special characteristics of the City, such as population (more than eight million inhabitants), and altitude (2600 m over the sea level). Relative humidity, temperature, and SO2 concentration were measured. Simultaneously, corrosion rate of AIS/SAE 1006 plain steel was measured along one year. Results show that atmospheric corrosion is between C<sub>2</sub> – C<sub>3</sub> levels, according to the ISO 9223 standard. Nevertheless, estimations from meteorological parameters produce lower corrosivities and, taking into account SO2 concentrations, corrosivities in places with higher relative humidity, are higher than corrosivities measured on steel coupons. In general, the main pollution problem is particulate matter, but higher corrosion rates were directly associated with SO2 levels. Gaps between found results and international estimation methodologies are evident. Some explanations about that, are proposed.<strong></strong></p>

scholarly journals The Influence of Test-Panel Orientation and Exposure Angle on the Corrosion Rate of Carbon Steel. Mathematical Modelling

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 196
Author(s):  
Juan J. Santana ◽  
Víctor Cano ◽  
Helena C. Vasconcelos ◽  
Ricardo M. Souto
Keyword(s):  
Mathematical Model ◽  
Carbon Steel ◽  
Atmospheric Corrosion ◽  
Test Panel ◽  
Marine Atmosphere ◽  
Corrosion Rates ◽  
Qualitative Variables ◽  
Logarithmic Law ◽  
Time Of Wetness ◽  
Good Agreement

The effects of both test-panel orientation and exposure angle on the atmospheric corrosion rates of carbon steel probes exposed to a marine atmosphere were investigated. Test samples were exposed in a tree-shape metallic frame with either three exposure angles of 30°, 45° and 60° and orientation north-northeast (N-NE), or eight different orientation angles around a circumference. It was found that the experimental corrosion rates of carbon steel decreased for the specimens exposed with greater exposure angles, whereas the highest corrosion rates were found for those oriented to N-NE due to the influence of the prevailing winds. The obtained data obtained were fitted using the bi-logarithmic law and its variations as to take in account the amounts of pollutants and the time of wetness (TOW) for each particular case with somewhat good agreement, although these models failed when all the effects were considered simultaneously. In this work, we propose a new mathematical model including qualitative variables to account for the effects of both exposure and orientation angles while producing the highest quality fits. The goodness of the fit was used to determine the performance of the mathematical models.

Effects of Deformation on Atmospheric Corrosion of Galvanized Steel

2006 ◽  
Vol 510-511 ◽  
pp. 1134-1137
Author(s):  
Jae Woong Choi ◽  
Gil Ho Hwang ◽  
Hong Rae Cha ◽  
Sung Goon Kang
Keyword(s):  
Relative Humidity ◽  
Corrosion Test ◽  
Atmospheric Corrosion ◽  
Surface Damage ◽  
Corrosion Products ◽  
Galvanized Steel ◽  
Accelerated Corrosion ◽  
Corrosion Rates ◽  
Accelerated Corrosion Test ◽  
Surface Morphologies

The effects of deformation on corrosion behavior of galvanized steel were investigated. Accelerated corrosion test was conducted under the conditions of 30oC and 90% relative humidity with flowing 200ppm sulfur dioxide gas for five weeks. Surface morphologies and corrosion products were analyzed by SEM/EDS and XRD. The corrosion products were composed of hydrates of ZnSO4. And corrosion rates of each part, bottom, bended and wall, were increased with growing strain due to surface damage and enlargement of naked surface for corrosion.

Corrosion Behaviors of Mg-7Gd-5Y-1Nd-0.5Zr Alloys in CO2 Atmosphere under Different Relative Humidity

2014 ◽  
Vol 900 ◽  
pp. 39-42
Author(s):  
Quan Tong Jiang ◽  
Xing Gang Li ◽  
Yong Jun Li ◽  
Ming Long Ma ◽  
Guo Liang Shi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Weight Loss ◽  
Relative Humidity ◽  
Influence Factors ◽  
Corrosion Morphology ◽  
Corrosion Rates ◽  
Corrosion Behaviors ◽  
Peak Aged ◽  
Residual Mechanical Properties ◽  
Loss Rates

The corrosion behaviors of peak-aged Mg-7Gd-5Y-1Nd-0.5Zr alloys in CO2atmosphere under different relative humidity were investigated by OM, SEM. The weight loss rates, corrosion morphology and residual mechanical properties were also analyzed. The corrosion rates of specimens in CO2atmosphere at 70% relative humidity were highest than others. Relevancy of the influence factors included relative humidity and concentration of CO2were researched. The results show that relative humidity and concentration of CO2in the environment both played an important role in corrosion behaviors.

scholarly journals Maps estimates of atmospheric corrosion of low alloy steel in Costa Rica

2015 ◽  
Vol 7 (2) ◽  
pp. 181-191
Author(s):  
Javier Rodríguez Yáñez ◽  
Luis Garita Arce ◽  
Ericka Saborío Leiva
Keyword(s):  
Costa Rica ◽  
Alloy Steel ◽  
Atmospheric Corrosion ◽  
Climatic Data ◽  
Local Models ◽  
Low Alloy Steel ◽  
Atmospheric Parameters ◽  
Corrosion Rates ◽  
Wetting Time ◽  
Low Levels

The Corrosion maps used are to display quickly the different situations in a country. These maps developed are for low alloy steel in Costa Rica depending on climatic data and pollutant levels, considering the different regulations associated with ISO 9223 and models developed by the Center for Research in Corrosion (CICorr). The atmosphere in Costa Rica has high rates of Brooks, considered very corrosive. The corrosion controlling atmospheric parameters are the relative humidity (RH) and Wetting Time (TWH) associated with low levels of pollution and rural type atmospheres. The corrosion rates are between 25 and 80μm*yr-1 (Class 3 and 4 according to ISO 9223). Local models associated with the controlling parameters are more suitable for estimating the corrosion according to ISO 9223.

Corrosive Environment Factors and their Influence on the Development of Weathering Steel Corrosion Products

2020 ◽  
Vol 832 ◽  
pp. 137-146
Author(s):  
Monika Kubzová ◽  
Vit Křivý ◽  
Viktor Urban ◽  
Katerina Kreislova
Keyword(s):  
Atmospheric Corrosion ◽  
Steel Surface ◽  
Protective Layer ◽  
Steel Structures ◽  
Corrosion Products ◽  
Outdoor Environment ◽  
Weathering Steel ◽  
Low Alloy Steels ◽  
Time Of Wetness ◽  
The Impact

This article deals with the topic of atmospheric corrosion. Atmospheric corrosion causes damage to nearly 80% of all existing steel structures. The main parameters of atmospheric corrosion are the time of wetness (TOW), air temperature and aggressive corrosive agents such as chlorides, sulfur dioxide and others. Currently, low alloy steels with improved atmospheric corrosion resistance called weathering steels are used for the steel structures located in outdoor environment. A protective layer of corrosion products is created on the steel surface and this layer can reduce continuation of corrosion of steel. The time of wetness together with the effect of aggressive corrosive agents are various for surfaces oriented vertically or horizontally. Experimental tests of atmospheric weathering steel were carried out to monitor the impact of location and position of surface on the different constructions. These tests allow monitoring the development of corrosion products in real exposures. The article presents a part of the research, which includes monitoring the development of the thickness of corrosion products with regard to the position on the structure. Research is developed to refine of prediction models with the aim of improving determination of corrosion losses during the service life of the structure. Second part of these experiments is dedicated to measuring the deposition rate of chlorides. Chlorides have a corrosive impact on the steel surface. Under normal conditions the chlorides does not create suitable environment for the development of a protective layer of corrosion products.

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