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

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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Corrosion Processes on Weathering Steel Bridges Influenced by Deposition of De-Icing Salts

Materials ◽

10.3390/ma12071089 ◽

2019 ◽

Vol 12 (7) ◽

pp. 1089 ◽

Cited By ~ 3

Author(s):

Vít Křivý ◽

Monika Kubzová ◽

Petr Konečný ◽

Kateřina Kreislová

Keyword(s):

Road Traffic ◽

Protective Layer ◽

Corrosion Products ◽

Weathering Steel ◽

The Road ◽

Protective Layers ◽

Different Types ◽

Time Of Wetness ◽

Chloride Deposition

The safety and durability of bridges designed from weathering steels are conditioned by the development of a sufficiently protective layer of corrosion products. Air pollution, microclimate around the bridge, time of wetness, structural solution of the bridge, and the position and orientation of the surface within the bridge structure all influence the development of protective layers on the surface of the weathering steel. In this article, attention is focused mainly on the microclimatic effects resulting from the road traffic under the bridge. The influence of chloride deposition on the development of corrosion products is evaluated using experimental in situ testing. Two neighboring bridges made of weathering steel and crossing different types of obstacles were selected for this experiment. Relations and dependences between the measured parameters (deposition rate of chlorides, corrosion rates, thickness of corrosion products and the amount of chlorides in corrosion products) are evaluated and discussed.

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Dissimilar Welding of Low Alloy Steels Welded Joints: Effect of Run-Off and Run-On Plates

Metals ◽

10.3390/met11040642 ◽

2021 ◽

Vol 11 (4) ◽

pp. 642

Author(s):

Park Jeongung ◽

Gyubaek An

Keyword(s):

Physical Properties ◽

Base Metal ◽

Physical Property ◽

Charpy Impact ◽

Steel Structures ◽

Dissimilar Welding ◽

Low Alloy Steels ◽

Run Off ◽

The Impact ◽

Grade Steel

The steel run-off plates attached at the start and end of a weld usually have the same material, shape, and groove as the base metal according to the rules for designing and constructing ship steel structures. However, rather than using the same grade of base steel, readily available steel is often used for these plates to increase material utilization. When using dissimilar grade steel as a run-off plate, the physical properties of the base metal may be diluted if the weld joint of the base plate is penetrated, thereby lowering the physical property value of the joint. If the physical properties of the welded part of the real structure are lowered because of the dilution of the properties of the dissimilar grade steel material, the safety of the entire structure can be affected. Therefore, in this study, analyses of the metal microstructure, hardness, impact, and chemical composition were performed on surfaces where the run-off plate was removed after welding to examine the effect of dissimilar run-off plate. The results of this study reveal that the properties of the run-off plate were not diluted toward the base metal and the Charpy impact value at the weld end was up to 48% greater than the impact value at the start of the weld at a temperature of −40 °C.

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Investigation of atmospheric corrosion with use of permanent corrosion stations

Research Works of Air Force Institute of Technology ◽

10.2478/v10041-012-0002-4 ◽

2012 ◽

Vol 30 (1) ◽

pp. 25-44 ◽

Cited By ~ 1

Author(s):

Piotr Barszcz

Keyword(s):

Atmospheric Corrosion ◽

Field Tests ◽

Research Process ◽

Technical Condition ◽

Corrosion Process ◽

Corrosion Products ◽

Physical Parameters ◽

Atmospheric Conditions ◽

The Impact

Field tests of atmospheric corrosion [7, 14, 15] are understood as investigation that are carried out in the Earth atmosphere at the ambient temperature in order to determine corrosion resistance of metals and pollution of environment by corrosion products, efficiency of corrosion protection or corrosion aggressiveness of environment [9, 11]. The investigation dedicated to prolongation of the technical service time of aircrafts as well implementation of their operation according to their actual technical condition are closely connected to investigation of corrosion processes under natural atmospheric conditions where specimens of materials are exposed to the impact of ambient factors and periodically subjected to tests that assume visual inspection, scheduled determination of weight and volume loss due to corrosion, appearance of specimens and alteration of their physical parameters [4]. Investigation results are obtained as measurements of weight and thickness of corroded specimens, photographs of specimen surfaces after withdrawing them back from the corrosion stations and removing corrosion products. On the basis of information acquired from investigations on corrosion it is possible to calculate parameters that are specific for the corrosion process that takes place within the region where a permanent corrosion station is located. The calculated parameters have been sourced from standards that are effective in Poland and worldwide [5, 6, 8, 10] but own specifications have also been developed based on the gained experience (Table 3). The research process involves also monitoring of atmospheric conditions that exist on the area where corrosion specimens are exposed [4]. Information related to atmospheric conditions is sourced from the Hydrometeorological Centre of Polish Army along with information that is published on the Internet by the Inspectorate of Environmental Protection. These information that reflect the atmospheric conditions make it possible to seek for the correlation between the parameters that are specific for the corrosion process and meteorological conditions.

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New atmospheric corrosion inhibitor of aluminum alloy D16

Corrosion Materials Protection ◽

10.31044/1813-7016-2020-0-11-38-46 ◽

2020 ◽

pp. 38-46

Author(s):

A.M. Semiletov ◽

◽

Yu.B. Makarychev ◽

A.A. Chirkunov ◽

L.P. Kazansky ◽

...

Keyword(s):

Aluminum Alloy ◽

Corrosion Inhibitor ◽

Atmospheric Corrosion ◽

Protective Layer ◽

Humid Atmosphere ◽

Water Condensation ◽

Equimolar Composition ◽

Aluminum Hydroxides ◽

Daily Water ◽

20 Nm

The application of mixed corrosion inhibitor (CI), which is an equimolar composition of oleoyl sarcosinate (SOS) and sodium flufenamate (SFF), for protection of D16 aluminum alloy from atmospheric corrosion has been studied. The polarization measurements used to assess the effectiveness of preliminary passivation of the alloy with solutions of SOS, SFF and their composition showed significant advantages of mixed CI. The XPS method was used to study features of CI adsorption on the surface of D16 alloy. It has been established that upon adsorption of SOS and SFF separately a monolayer is formed, firmly bonded to the alloy surface, thickness of which is not exceeding 2.6—3.2 nm. After the joint adsorption of these CI, the layer thickness reaches 12—20 nm. The composition of this layer includes a considerable amount of Al3+ ions (~20%) related to their compounds with SFF and SOS, as well as to aluminum hydroxides. A possible mechanism for the formation of such a protective layer is proposed. The results of corrosion tests in a humid atmosphere with daily water condensation on samples of D16 alloy confirmed the high protective ability of the mixed CI film.

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Impact resistance of steel materials to ballistic ejecta and shelter development using steel deck plates

Journal of Applied Volcanology ◽

10.1186/s13617-021-00105-8 ◽

2021 ◽

Vol 10 (1) ◽

Author(s):

Hiroyuki Yamada ◽

Kohei Tateyama ◽

Shino Naruke ◽

Hisashi Sasaki ◽

Shinichi Torigata ◽

...

Keyword(s):

Impact Energy ◽

Impact Test ◽

Impact Resistance ◽

Protective Layer ◽

High Strength ◽

Steel Plates ◽

Corrugated Plates ◽

Shelter Construction ◽

The Impact ◽

Ballistic Ejecta

AbstractThe destruction caused by ballistic ejecta from the phreatic eruptions of Mt. Ontake in 2014 and Mt. Kusatsu-Shirane (Mt. Moto-Shirane) in 2018 in Japan, which resulted in numerous casualties, highlighted the need for better evacuation facilities. In response, some mountain huts were reinforced with aramid fabric to convert them into shelters. However, a number of decisions must be made when working to increase the number of shelters, which depend on the location where they are to be built. In this study, we propose a method of using high-strength steel to reinforce wooden buildings for use as shelters. More specifically, assuming that ballistic ejecta has an impact energy of 9 kJ or more, as in previous studies, we developed a method that utilizes SUS304 and SS400 unprocessed steel plates based on existing impact test data. We found that SUS304 is particularly suitable for use as a reinforcing material because it has excellent impact energy absorption characteristics due to its high ductility as well as excellent corrosion resistance. With the aim of increasing the structural strength of steel shelters, we also conducted an impact test on a shelter fabricated from SS400 deck plates (i.e., steel with improved flexural strength provided by work-hardened trapezoidal corrugated plates). The results show that the shelter could withstand impact with an energy of 13.5 kJ (2.66 kg of simulated ballistic ejecta at 101 m/s on impact). In addition, from the result of the impact test using the roof-simulating structure, it was confirmed the impact absorption energy is further increased when artificial pumice as an additional protective layer is installed on this structure. Observations of the shelter after the impact test show that there is still some allowance for deformation caused by projectile impact, which means that the proposed steel shelter holds promise, not only structurally, but also from the aspects of transportation and assembly. Hence, the usefulness of shelters that use steel was shown experimentally. However, shelter construction should be suitable for the target environment.

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Window operation behaviour and indoor air quality during lockdown: A monitoring-based simulation-assisted study in London

Building Services Engineering Research and Technology ◽

10.1177/01436244211017786 ◽

2021 ◽

pp. 014362442110177

Author(s):

Farhang Tahmasebi ◽

Yan Wang ◽

Elizabeth Cooper ◽

Daniel Godoy Shimizu ◽

Samuel Stamp ◽

...

Keyword(s):

Air Quality ◽

Indoor Air Quality ◽

Indoor Air ◽

Energy Demand ◽

Natural Ventilation ◽

Probabilistic Models ◽

Performance Model ◽

Outdoor Environment ◽

Ventilation Strategies ◽

The Impact

The Covid-19 outbreak has resulted in new patterns of home occupancy, the implications of which for indoor air quality (IAQ) and energy use are not well-known. In this context, the present study investigates 8 flats in London to uncover if during a lockdown, (a) IAQ in the monitored flats deteriorated, (b) the patterns of window operation by occupants changed, and (c) more effective ventilation patterns could enhance IAQ without significant increases in heating energy demand. To this end, one-year’s worth of monitored data on indoor and outdoor environment along with occupant use of windows has been used to analyse the impact of lockdown on IAQ and infer probabilistic models of window operation behaviour. Moreover, using on-site CO2 data, monitored occupancy and operation of windows, the team has calibrated a thermal performance model of one of the flats to investigate the implications of alternative ventilation strategies. The results suggest that despite the extended occupancy during lockdown, occupants relied less on natural ventilation, which led to an increase of median CO2 concentration by up to 300 ppm. However, simple natural ventilation patterns or use of mechanical ventilation with heat recovery proves to be very effective to maintain acceptable IAQ. Practical application: This study provides evidence on the deterioration of indoor air quality resulting from homeworking during imposed lockdowns. It also tests and recommends specific ventilation strategies to maintain acceptable indoor air quality at home despite the extended occupancy hours.

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Efficiency of Organic Corrosion Inhibitors Derived from Thai-Bael Fruit Extract for Preventing Corrosion in Carbon Steels

Asian Journal of Chemistry ◽

10.14233/ajchem.2020.22743 ◽

2020 ◽

Vol 32 (8) ◽

pp. 2043-2050

Author(s):

Phattarasuda Manantapong ◽

Nattanon Chaipunya ◽

Suttipong Wannapaiboon ◽

Prae Chirawatkul ◽

Worawat Wattanathana ◽

...

Keyword(s):

Electrochemical Impedance Spectroscopy ◽

Impedance Spectroscopy ◽

Steel Surface ◽

Electrochemical Impedance ◽

Protective Layer ◽

Corrosion Current ◽

Carbon Steels ◽

Fruit Extract ◽

Polarization Measurements ◽

Hcl Solution

The inhibiting action of Thai-bael fruit extract at room temperature on hot-rolled steel in 1M HCl solution was studied. The chemical functional groups of the green inhibitors were characterized by Fourier-transformed infrared spectroscopy. The electrochemical activities of steel surface were investigated through linear polarization measurements, electrochemical impedance spectroscopy, surface assessment techniques based on optical microscopy and X-ray absorption spectroscopy. Electrochemical testing samples have been prepared in the form of square plates with the size 1 × 1 cm2. The organic corrosion inhibitor extract from Thai-bael fruit has shown the smallest corrosion current density (Icorr) of 114.8 μA cm-2 and corrosion potential (Ecorr) of -424.6 mV, compared with standard Ag/AgCl electrode potential. In comparison, similar tests in the bare HCl solutions yielded Icorr = 882.4 mA cm-2 and Ecorr = -445.8 mV. The mixed-type corrosion inhibiting behaviour was evidenced in the results of the polarization measurements. Electrochemical impedance spectroscopy reveals that the resistance to charge transfer due to the presence of the extracts has been increased by about four times that of the same test on the bare HCl solution, indicating the formation of a protective layer. The adsorption of the organic molecules near the steel-electrolyte interface is evident in the decreasing double-layer capacitance with the enhancing concentration levels of the extract. This latter finding supports the displacement of the water molecules by means of the adsorption of the inhibitors on the steel surface. The optical images of steel surface before and after being immersed in HCl solution also showed pieces of evidence of corrosion retardation. XANES study as well as the linear combination fitting revealed that the samples immersed in HCl solutions with Thai-bael fruit extract possess less Fe3+ compositions. All tendencies across the four examinations indicate that Thai-bael fruit extract could potentially inhibit the corrosion reaction of steel electrodes in the acidic solution.

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Optimizing the resistance of Ni-advanced weathering steel to marine atmospheric corrosion with the addition of Al or Mo

Construction and Building Materials ◽

10.1016/j.conbuildmat.2021.122341 ◽

2021 ◽

Vol 279 ◽

pp. 122341

Author(s):

Xuexu Xu ◽

Tianyi Zhang ◽

Wei Wu ◽

Shan Jiang ◽

Jianwei Yang ◽

...

Keyword(s):

Atmospheric Corrosion ◽

Weathering Steel

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Implications of Building Material Choice on Outdoor Microclimate for Sustainable Built Environment

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.650.82 ◽

2015 ◽

Vol 650 ◽

pp. 82-90 ◽

Cited By ~ 1

Author(s):

D. Kannamma ◽

A. Meenatchi Sundaram

Keyword(s):

Thermal Comfort ◽

Building Material ◽

Building Materials ◽

Climatic Factors ◽

Outdoor Environment ◽

Outdoor Thermal Comfort ◽

Physical Factors ◽

Physiological Equivalent Temperature ◽

Material Choice ◽

The Impact

The climatic conditions in a man-made urban environment may differ appreciably from those in the surrounding natural or rural environs.... each urban man-made buildings, roads, parking area, factories......creates around and above it a modified climate with which it interacts [1].Outdoor thermal comfort has gained importance in thermal comfort studies especially in tropical countries. In country like India, culturally the activities are spread both indoors and outdoors. Therefore the need for ambient outdoor environment gains importance. As there are many factors that contribute to outdoor thermal comfort (climatic factors and physical factors), this study aims in analyzing the impact of building material contribution, in an institutional courtyard. In order to understand the thermal contribution of various building materials and to suggest material choice to designers, ENVIMET is used for simulation purpose. The outdoor thermal comfort index employed in this study is PET (Physiological Equivalent Temperature), calibrated using RAYMAN.

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