Moisture Distribution in Porous Oxide and Polymer Over-Layers and Critical Relative Humidity and Time of Wetness for Chloride and Non-Chloride-Bearing Atmospheres for Atmospheric Corrosion of Metals

The hygroscopicity property of the rapeseed at different temperature and humidity was experimental studied in this paper. Tested results show that: the moisture absorption rates increase with the increase of relative humidity at the early period of absorption, and higher temperature leads to earlier reach of moisture equilibrium; the critical relative humidity(CRH) increases with the increase of temperature; the optional relative humidity for safety storage of rapeseed should be controlled less than 60%.

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Calculating the Critical Relative Humidity from the Solubility of Electrolyte According to Extended Non-random Two Liquid Model

Chemical and Pharmaceutical Bulletin ◽

10.1248/cpb.57.943 ◽

2009 ◽

Vol 57 (9) ◽

pp. 943-947 ◽

Cited By ~ 5

Author(s):

Yingli Wang ◽

Xiancheng Zhan ◽

Chaoqun Xiang ◽

Jia Chen ◽

Lan Cao ◽

...

Keyword(s):

Relative Humidity ◽

Liquid Model ◽

Critical Relative Humidity

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.832.137 ◽

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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Three years outdoor exposure of low carbon steel in Mauritius

Anti-Corrosion Methods and Materials ◽

10.1108/acmm-12-2013-1328 ◽

2015 ◽

Vol 62 (4) ◽

pp. 246-252 ◽

Cited By ~ 2

Author(s):

Baboo Y. R. Surnam

Keyword(s):

Carbon Steel ◽

Atmospheric Corrosion ◽

Corrosion Behaviour ◽

Low Carbon Steel ◽

Exposure Period ◽

Outdoor Exposure ◽

Low Carbon ◽

Steel Buildings ◽

Content Type ◽

Time Of Wetness

Purpose – This paper aims to investigate the corrosion behaviour of carbon steel in the Mauritian atmosphere over a three-year period. Atmospheric corrosion is a serious problem in Mauritius. Design/methodology/approach – Carbon steel samples were exposed outdoors at various sites. Mass loss analysis was performed to determine the corrosion behaviour of the metal over the exposure period. Scanning electron microscopy and Raman tests were performed to investigate the formation of the corrosion products on the carbon steel surface. Findings – It was found that the corrosion loss at two of the sites considered did not vary clearly according to the bilogarithmic law. Time of wetness was found to be a main factor affecting atmospheric corrosion in Mauritius. The corrosivity of the atmosphere was found to lie between categories C3 and C4, according to ISO 9223. Originality/value – The results can be of essential help to the construction industry, especially as steel buildings are becoming very common in Mauritius. Moreover, as Mauritius is a tropical island, the results obtained can be useful in other tropical islands.

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The atmospheric conditions affecting sporulation of blue mould in tobacco

Australian Journal of Experimental Agriculture ◽

10.1071/ea9640178 ◽

1964 ◽

Vol 4 (13) ◽

pp. 178 ◽

Cited By ~ 2

Author(s):

BG Collins

Keyword(s):

Wind Speed ◽

Relative Humidity ◽

Air Temperature ◽

Critical Parameter ◽

Leaf Surface ◽

Atmospheric Conditions ◽

Blue Mould ◽

Growing Seasons ◽

Ambient Relative Humidity ◽

Critical Relative Humidity

Conditions favouring sporulation of blue mould (Peronospora tabacina Adam) having been established in the laboratory, a theoretical model has now been used to express the critical parameter, i.e. the relative humidity near the leaf surface where the spores form, in terms of the ambient atmospheric conditions. To test the validity of this model, wind speed, air temperature, and relative humidity mere measured over four growing seasons in three tobacco crops in the Ovens Valley, Victoria, and related to times of sporulation of the mould observed concurrently in these crops. 'Critical relative humidity,' a function of wind speed, air temperature, and heat loss from the crop is shown to be a more serviceable indicator of likelihood of sporulation than either ambient relative humidity or rainfall.

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