Analysis Acid Corrosion Behavior of Epoxy Coating under Stress

2011 ◽  
Vol 413 ◽  
pp. 336-340
Author(s):  
Xin E Yan ◽  
Xiao Bei Su

By analyzing effort factors of epoxy coating adhesion such as water absorption, acid corrosion and cycles stress, the acid carrion behaviors of epoxy resins as coating under stress have be evaluated. The results showed that under solution swelling, mechanical load and aggressive media interaction, epoxy coating adhesion drop distinctly and completely lost the ability of corrosion protection.

2005 ◽  
Vol 59 (11-12) ◽  
pp. 317-320
Author(s):  
Milica Gvozdenovic ◽  
Branimir Grgur ◽  
Zorica Kacarevic-Popovic ◽  
Vesna Miskovic-Stankovic

The corrosion behavior and thermal stability of epoxy coatings electrodeposited on mild steel and on mild steel with electrochemically deposited polyaniline (PANI) film were investigated by electrochemical impedance spectroscopy (EIS) and thermo gravimetric analysis (TGA). The aim of the paper was to present new findings on the corrosion protection of mild steel by a duplex PANI/-epoxy coating in 3% NaCI solution and to determine the effect of thin PANI film on the protective properties of the coating. PANI film was deposited electrochemically on mild steel from an aqueous solution of 0.5 mol dm"3 sodium benzoate and 0.1 mol dm"3 aniline at a constant current density of 1.5 mA cm"2. Non-pigmented epoxy coatings on mild steel and on mild steel with PANI film were obtained by cathodic electrode position at constant voltage and stirring conditions. The resin concentration in the electrode position bath was 10 wt.% solid dispersion in water at pH 5.7. The applied voltage was 250 V, the temperature 26?C and the deposition time 3 min. It was shown that thin PANI film could be used to modify the surface of mild steel prior to epoxy coating deposition, due to the increased corrosion protection of a duplex PANI/epoxy coating comparing to an epoxy coating on mild steel in 3% NaCl solution.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 113
Author(s):  
Jacob Ress ◽  
Ulises Martin ◽  
Juan Bosch ◽  
David M. Bastidas

The protection of mild steel by modified epoxy coating containing colophony microencapsulated corrosion inhibitors was investigated in this study. The corrosion behavior of these epoxy coatings containing colophony microcapsules was studied by electrochemical analysis using cyclic potentiodynamic polarization and electrochemical impedance spectroscopy. The microcapsule coating showed decreased corrosion current densities of 2.75 × 10−8 and 3.21 × 10−8 A/cm2 along with corrosion potential values of 0.349 and 0.392 VSCE for simulated concrete pore solution and deionized water with 3.5 wt.% NaCl, respectively, indicating improved corrosion protection in both alkaline and neutral pH. Electrochemical impedance spectroscopy analysis also showed charge transfer resistance values over one order of magnitude higher than the control sample, corroborating the electrochemical corrosion potential and current density testing results. Overall, the use of colophony microcapsules showed improved corrosion protection in simulated concrete pore solution and DI water solutions containing chloride ions.


Author(s):  
Akarsh Verma ◽  
Kamal Joshi ◽  
Amit Gaur ◽  
V. K. Singh

In this article, bio-composites derived from starch-glycerol biodegradable matrix reinforced with jute fibers have been fabricated using the wet hand lay-up and compression moulding techniques. Samples having different weight percentages of jute fiber in the starch matrix have been analysed. The fibers surface was chemically treated by alkaline sodium hydroxide for improving the interphase bonding between fiber and matrix. Tensile test for the composites were done and the sample with highest tensile strength was selected for further tests that included water absorption, scanning electron microscopy and thermal analysis. It has been concluded that the ultimate tensile strength was found to be maximum for the composition of 15% fiber by weight composite as 7.547 MPa without epoxy coating and 10.43 MPa with epoxy coating. The major disadvantage of bio-composite is its high water absorption property, which in this study has been inhibited by the epoxy resin layer. Herein, the results of various tests done disclose a noteworthy improvement in the overall properties of bio-composite, in comparison to the neat biodegradable starch matrix.


Author(s):  
M.A. Serekpayeva ◽  
◽  
G.А. Kokayeva ◽  
R.K. Niyazbekova ◽  
S. Kardybai ◽  
...  

The outcomes of studying epoxy-based composite materials supplemented with microsilica are provided in the article. Microsilica was used as a filler. The samples were produced on the epoxy ED-20 basis supplemented with 2, 5 and 10 mas. % of microsilica. The structure and size of finely dispersed filler particles were defined. The obtained composites were tested for resistance to the effect of variable temperatures, corrosive, and abrasion. The study outcomes proved that samples supplemented with 2% of microsilica are more resistant to acid and alkali as well as to petrol than those ones supplemented with 25% of microsilica. Besides the amount of the filler from 2 to 10% doesn’t sufficiently affect the resistance to variable temperatures. When microsilica is added to epoxy resin, it causes scuff resistance increase. The conducted testing proved that the developed composite materials are resistant to the effect of variable temperatures, corrosive, and abrasion. This enables to use these materials as coatings and anti-corrosion protection during machine maintenance.


1993 ◽  
Vol 03 (C4) ◽  
pp. 249-252 ◽  
Author(s):  
T. MIURA ◽  
T. SUZUKI ◽  
Y. OKI ◽  
M. NUMAJIRI ◽  
K. KONDO ◽  
...  

2012 ◽  
Vol 96 (3) ◽  
pp. 923-927 ◽  
Author(s):  
Stanislav Kurajica ◽  
Lidija Curkovic ◽  
Emilija Tkalcec ◽  
Vilko Mandic

Author(s):  
Александр Михайлович Ефремов ◽  
Петр Дмитриевич Волянский ◽  
Павел Олегович Ревин ◽  
Сергей Владимирович Ануфриев

При сооружении трубопроводов в России, странах Европы и Африки наиболее распространенным является применение труб с трехслойными полиэтиленовыми покрытиями. В то же время опыт строительства магистральных нефте- и газопроводов в США, Канаде, ряде других стран свидетельствует о возможности использования эпоксидных покрытий в качестве эффективной антикоррозионной защиты труб. В этой связи была начата научно-исследовательская работа по определению целесообразности применения двухслойных эпоксидных покрытий для антикоррозионной защиты магистральных трубопроводов подземной прокладки, эксплуатируемых организациями системы «Транснефть». Цель настоящего исследования - оценка технической и экономической целесообразности использования эпоксидных покрытий как альтернативы полиэтиленовой изоляции трубопроводов. Были проведены лабораторные исследования образцов трех систем эпоксидных покрытий, осуществлен сравнительный анализ технических свойств эпоксидной и полиэтиленовой изоляции. Установлено, что эпоксидные покрытия превосходят полиэтиленовые по ряду свойств, в частности обладают повышенной стойкостью к температурным воздействиям, УФ-излучению, катодному отслаиванию, а также повышенной механической прочностью, что позволяет обеспечить сохранность покрытия при строительстве трубопроводов методом наклонно-направленного бурения и прокладке в скальных грунтах. Основные мощности по производству сырья для эпоксидных порошковых покрытий локализованы в России, в то время как сырье для полиэтиленовых покрытий в основном производится за рубежом. Установлена экономическая целесообразность применения двухслойного эпоксидного покрытия как альтернативы трехслойному полиэтиленовому покрытию для трубопроводов больших диаметров - более 720 мм. Для внедрения труб с двухслойным эпоксидным покрытием на объектах ПАО «Транснефть» проводится его апробация, включающая строительство опытного участка трубопровода. When constructing pipelines in Russia, Europe, and Africa, it is the most common to use pipes with threelayer polyethylene coatings. At the same time, the oil and gas pipeline construction experience in the USA, Canada, and a number of other countries, as well as the construction of the Zapolyarye - Purpe elevated main pipeline by Transneft PJSC, indicates the possibility of using epoxy coatings as an effective pipe corrosion protection solution. In respect thereof, research study to determine the feasibility of using two-layer epoxy coatings for corrosion protection of underground pipelines operated by the Transneft system entities was instituted. The purpose of this study is to assess the technical and economic feasibility of using epoxy coatings as an alternative to polyethylene insulation of pipelines. Laboratory studies of samples of three epoxy coating systems, as well as a comparative analysis of the process properties of epoxy and polyethylene insulation were conducted. It has been established that epoxy coatings are superior to polyethylene coatings in a number of properties, in particular, they are characterized by increased resistance to temperature effects, UV radiation, cathodic disbondment, as well as increased mechanical strength, which makes it possible to ensure safety of the coating during the construction of pipelines by directional drilling and laying in rocky soils. The main production facilities for raw materials for epoxy powder coatings are localized in Russia, while raw materials for polyethylene coatings are mainly produced abroad. The economic feasibility of using a twolayer epoxy coating as an alternative to a three-layer polyethylene coating for pipelines of large diameters (over 720 mm (28 in)) was established. Testing for the introduction of pipes with a two-layer epoxy coating at the Transneft PJSC facilities is being performed, including construction of an experimental pipeline section.


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