scholarly journals Evaluation of Protective Coatings for High-Corrosivity Category Atmospheres in Offshore Applications

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1325 ◽  
Author(s):  
Ainara López-Ortega ◽  
Raquel Bayón ◽  
José Luís Arana

The interest in renewable energies obtained from the resources availed in the ocean has increased during the last few years. However, the harsh atmospheric conditions in marine environments is a major drawback in the design of offshore structures. The protective systems that are employed to preserve offshore steel structures are regulated by several standards (ISO 12944, NORSOK M-501), which classify the corrosivity category of offshore installations as C5-M and Im2. In this work, three coatings employed in offshore components protection have been evaluated according to these standards by performing weathering aging tests in different climatic cabinets. The coatings studied were a thermally sprayed carbide coating with an organic sealant (C1), a thermally sprayed aluminum (TSA) coating with an organic topcoat (C2), and an epoxydic organic coating reinforced with ceramic platelets (C3). The only coating that reached the higher categories in all the tests was the C2 coating. The C1 coating presented ferric corrosion products coming from the substrate in some of the tests, and blistering was detected in the C3 coating.

2019 ◽  
Vol 121 ◽  
pp. 02003
Author(s):  
Gennadiy Konovalov

The article discusses options for optimal repair systems with several advantages compared with competitive solutions in the market of protective coatings. The proposed materials have a high tolerance to the degree of surface preparation, compatibility with old protective systems, as well as low levels of internal stresses arising in the repair layer of coating, which significantly reduces the risk of pulling off the old protective coatings after repair.


2021 ◽  
Vol 31 (2) ◽  
pp. 30-42
Author(s):  
Marek Henryk Dohojda ◽  
Beata Backiel-Brzozowska ◽  
Bożena Dohojda

Abstract The article presents important problems occurring in the operation of large-size steel structures protected by paint coatings. In our atmospheric conditions, corrosion of steel structures cannot be avoided, even with the use of protective coatings. The problem of environmental pollution with corrosion products and exfoliated paint then appears. When designing corrosion protection, durability of protection is assumed based on environmental corrosivity categories, but in practice degradation of paint coatings can occur much faster. The problem of premature peeling of paint results, among other things, from its faulty application and use. Steel structure repairs are usually carried out comprehensively, and new protection requires the removal of damaged coatings, mainly by sanding. As a result of the mechanical action of the abrasive material, old paints and corrosion products are removed, which results in a very large amount of waste that settles on the adjacent area. Due to the age of paint removed, this waste often contains compounds such as lead, chromium or zinc, which pose a real threat to the natural environment around the renovated buildings. In the article, based on the observations carried out directly on the exemplary structures in renovation, the actual scope of the waste emission was determined. This is a contribution to further spectrometric studies to determine the exact area of contamination and to identify heavy metals in the waste arising from the renovation of steel structures with paint coatings.


2019 ◽  
Vol 28 (4) ◽  
pp. 645-677 ◽  
Author(s):  
Sahar A. Galedari ◽  
Amirhossein Mahdavi ◽  
Fardad Azarmi ◽  
Ying Huang ◽  
André McDonald

2010 ◽  
Vol 44-47 ◽  
pp. 610-613
Author(s):  
Qiang Liu ◽  
Bing Jian Zhang

The conservation of historic stone buildings and sculptures is receiving growing attention because of weathering. Now, the techniques for stone conservation are primarily achieved through the use of organic coating treatments. Although some defects of organic protective materials have been recognized, the further shortcoming is still short of awareness. Here we show our investigations of the side effect of organic coating treatments. Some kinds of common stones, including sandstone, tuff, granite, dolomite and marble, were selected as protected objects. Organic silicon compounds were used as protective coatings. The artificial weathering, including salting, freezing and heating, was designed. The treated stones’ decaying was investigated. The results reveal that the treated stone decaying is aggravated. Moreover, the destruction mechanism has been discussed.


2019 ◽  
Vol 26 (4) ◽  
pp. 90-100
Author(s):  
Jacek Łubiński ◽  
Henryk Olszewski

Abstract In the design process of offshore steel structures, it is typical to employ commercial calculation codes in which simulation and evaluation of results are performed on the basis of the available standards (e.g. API, DNV, Lloyds). The modeling and solution rely on finite element methods and cover the simulation of the structure’s properties along with the influence of the marine environment – sea currents, wave and wind loading, as well as the influence of vibrations, buoyancy and accompanying mass of water. Both commercial and open source mathematical modeling software which is available nowadays allows for cost effective and flexible implementation of advanced models for offshore industrial structures with high level of credibility and safety. The models can be built to suit task-specific requirements and evaluated on the basis of the selected criterial system best suited to the needs of the customer. Examples of methodology for environmental and structural model development are presented, along with simulation results covering a wide scope of data, ranging from stress and deformation to resonant characteristics and issues of technological feasibility.


2020 ◽  
Vol 318 ◽  
pp. 01008
Author(s):  
Alina Timmermann ◽  
Mohamed Abdulgader ◽  
Leif Hagen ◽  
Alexander Koch ◽  
Philipp Wittke ◽  
...  

Thermally sprayed protective coatings are applied onto many mechanically stressed components such as support structures, shafts, turbine blades or heat exchangers. In addition to the static or cyclic load, a superimposition with corrosion processes occurs in many cases. Thermal sprayed ZnAl coatings are known for their performant corrosion protection properties. Within this context, the potential of ZnAl-based layer systems was analyzed regarding corrosion fatigue behavior. Therefore, a timeand cost-efficient testing strategy based on a corrosion-superimposed load increase procedure was used to estimate the effects of a corrosive attack during cyclic loading. The investigated coating systems were thermally sprayed and partially post-processed with a Machine Hammer Peening (MHP) operation. This treatment was identified as an appropriate technique for compressing and smoothing coated surfaces. The inter-relationships between the parametrization of the MHP process, the resulting surface integrity, and the estimated corrosion fatigue properties were analyzed. The investigations indicate a positive effect of MHP post-processing operations on the surface properties of the ZnAl-based coating system.


2017 ◽  
Author(s):  
Larry Stephenson ◽  
Alfred Beitelman ◽  
Richard Lampo ◽  
Ashok Kumar ◽  
Douglas Neale ◽  
...  

2021 ◽  
Author(s):  
Sathishkumar Pragasam

Abstract The impact of artificial lighting on birds and animals has been a subject of research for many decades. These studies have established that light pollution from offshore facilities result in disturbing effects on migratory birds and marine animals. It is understood from the various studies that light emanating from offshore structures attract birds at night and disorient them during their migratory flight. As they are distracted from their flight path, they are either found trapped by the light that they keep circling around the installations or make them to take shelter in the installations, ultimately making them miss their migratory journey. This results in reduced winter survival and reduced reproduction success. Many birds are also found to die eventually because of bird strike or by getting themselves incinerated in flares. Congregation of birds in offshore installations also lead to risks related to helicopter landing / take-off. It is also observed that artificial light attracts marine species like turtles and fishes, which result in adverse effects like alteration of feeding habits, impacted circadian rhythm and interference with their reproductive function. From the knowledge of aforementioned disruptive effects of artificial lighting, significant efforts have been made to develop lighting systems for offshore installations that are eco-friendly. Various means of mitigating the undesirable effects of artificial lighting in offshore installations are being tried in the last couple of decades.


Author(s):  
T. Lester ◽  
S.J. Harris ◽  
D. Kingerley ◽  
S. Matthews

Abstract Thermal spraying has been used to protect many steel structures from aqueous corrosion using Zinc and Aluminium, and to some extent their alloy coatings to provide galvanic protection. The lifetimes of the coatings can approach 50 years even when exposed in severe marine environments. Zinc coatings work by continuously sacrificing themselves and slowly dissipating over time. Aluminium coatings passivate more readily and form a barrier layer, the passivity makes them less able to protect damaged areas and to self heal. A new ternary coating system involving Aluminium, Zinc and Magnesium has been shown to be capable of providing both a passive barrier layer as well as being able to give galvanically active protection. Salt spray tests have shown that the resistance to red rust of these new coatings increases by 300% over similar thicknesses of the separate metal coatings. Processing by arcspray is straightforward and both adhesion and deposition efficiency are better than where Zinc is sprayed alone.


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