Effect of CO2 on Anti-Corrosion Property of a Polyurea Coating Modified with Organosilicone

2014 ◽  
Vol 789 ◽  
pp. 466-470
Author(s):  
Qing Hao Shi ◽  
Bing Ying Wang ◽  
Bin Zhao

The corrosion mechanism of organic silicon modified polyurea composite coating under different CO2 partial pressures was studied using high-temperature autoclave, combined with scanning electron microscopy (SEM), adhesion tests and electrochemical impedance spectroscopy (EIS) technology. The experimental results showed that: there was no corrosion product formed on the surface of coating sample after high-temperature high-pressure corrosion test, and with the increasing of CO2 partial pressure, the coating adhesion and impedance values decline increases. Moreover CO2 partial pressure increases accelerated the failure process of polyurea composite coating system.

2015 ◽  
Vol 659 ◽  
pp. 555-559 ◽  
Author(s):  
Wichuda Wongtanasarasin ◽  
Rachsak Sakdanuphab ◽  
Kajpanya Suwansukho ◽  
Aparporn Sakulkalavek

In this study, we investigate a facet of the fabrication process of chromium nitride (CrN) film intended as a protective coating for pineapple blades. CrN thin films were deposited on unpolished stainless steel substrates (AISI304) by DC reactive magnetron sputtering in Ar+N2 gases. In principle, the proportion of nitrogen partial pressure to the total pressure in the sputtering process should have considerable effects on the CrN film’s chemical composition, its crystal structure, its hardness, and its corrosion resistance. We tested this supposition out by using several different nitrogen partial pressures in the sputtering process and observed the films deposited. The coatings were deposited at five different nitrogen partial pressures of 4.0x10-4 mbar, 8.0x10-4 mbar, 1.2x10-3 mbar, 1.6x10-3 mbar, and 2.0x10-3. The deposition times were controlled to achieve 5-µm thick films in each deposition. The films were analyzed by several analytical methods, such as X-ray diffraction (XRD), scanning electron microscope, micro-hardness and potentiostat in pineapple juice. The XRD spectra of the films showed face-centered cubic structure with (200) preferred orientation, positively identifying them as Cr2N and CrN thin films. The calculated d-spacing and lattice parameter of the CrN films increased with increasing nitrogen partial pressure; the ranges were 0.283–0.287 nm and 0.491-0.497 nm, respectively. The cross-section morphology of the CrN films reveals the columnar grain growth with a high density. The crystal structure and the grain texture correspond with the hardness property. The films corrosion potential, an indicator of their corrosion property, was varied from -0.14 to -0.05 volts with varying nitrogen pressure. The most corrosion resistant and the good hardness were the film fabricated at the nitrogen partial pressure of 1.2x10-3 mbar.


2018 ◽  
Vol 5 (7) ◽  
pp. 180405 ◽  
Author(s):  
Peng Xu ◽  
Zhengwu Tao ◽  
Zhihong Wang

A series of corrosion problems caused by high-temperature, high-pressure and high-acid gas environments has been an issue in oil and gas production for a long time. During the development of a high-acid gas field, the petroleum pipe is subjected to many aspects of corrosion, and the corrosion mechanism is complicated by the condition of the coexistence of H 2 S/CO 2 . Based on the study of the corrosion problem associated with the formate packer fluid in Southwest China, three kinds of steels were studied for corrosion prevention in the alloy G3/N80 steel/TP110SS steel. The study shows that the corrosion rate of the formate packer fluid is low, but corrosion is severe in environments characterized by high temperatures, high pressures and high-acid gas contents. Based on the consideration of cost and the difficulty of realization, an anti-corrosion system was constructed based on the existing packer fluid, mainly through the introduction of a variety of anti-corrosion additives. Through the selection of various additives and corrosion experiments, a corrosion protection system of formate packer fluid was developed. Corrosion tests show that the corrosion rate of the system must be less than 0.076 mm yr −1 to achieve the purpose of corrosion protection. The formate packer fluid with corrosion protection can meet the needs of the current application.


2012 ◽  
Vol 576 ◽  
pp. 429-433
Author(s):  
Hanafi Ani Mohd ◽  
Sukreen Hana Herman ◽  
Suryanto ◽  
Raihan Othman

Alloys for high temperature application always rely on their ability to form protective, dense Cr2O3 and Al2O3 scales. In case of Ni-Cr binary alloy, a minimum composition of Cr is required for the formation of continuous protective scale. However, addition of small amount of third element such as Al may results in decrease of required Cr composition to form protective scale. This study aims to clarify the effect of ternary element on the formation of protective scale quantitatively. Ni-Cr alloys composed with 2 mass% and 4 mass% of Al were exposed in oxidizing environment under Cr/Cr2O3, Fe/FeO and Ni/NiO oxygen partial pressure. The oxidation of all samples is following parabolic rate’s law. XRD and SEM results show that Al2O3 and Cr2O3 are formed internally. Parabolic rate’s constant of samples oxidized in Ni/NiO oxygen partial pressure is higher by few magnitude orders. Higher Al concentration decreases the parabolic rate’s constant. It is concluded that the formation of protective scale is enhanced by the addition of Al as ternary element in Ni-Cr alloys.


Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2614 ◽  
Author(s):  
Xiuqing Fu ◽  
Wenke Ma ◽  
Shuanglu Duan ◽  
Qingqing Wang ◽  
Jinran Lin

In order to study the effect of nano-CeO2 particles doping on the electrochemical corrosion behavior of pure Ni-Fe-Co-P alloy coating, Ni-Fe-Co-P-CeO2 composite coating is prepared on the surface of 45 steel by scanning electrodeposition. The morphology, composition, and phase structure of the composite coating are analyzed by means of scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The corrosion behavior of the coatings with different concentrations of nano-CeO2 particles in 50 g/L NaCl solution is studied by Tafel polarization curve and electrochemical impedance spectroscopy. The corrosion mechanism is discussed. The experimental results show that the obtained Ni-Fe-Co-P-CeO2 composite coating is amorphous, and the addition of nano-CeO2 particles increases the mass fraction of P. With the increase of the concentration of nano-CeO2 particles in the plating solution, the surface flatness of the coating increases. The surface of Ni-Fe-Co-P-1 g/L CeO2 composite coating is uniform and dense, and its self-corrosion potential is the most positive; the corrosion current and corrosion rate are the smallest, and the charge transfer resistance is the largest, showing the best corrosion resistance.


2021 ◽  
Vol 945 (1) ◽  
pp. 012043
Author(s):  
Jiang Lv ◽  
Zhi-li Chen

Abstract Distillation desalination can use solar energy and other renewable energy, it is one of the most potential technologies for desalination. However, distillation desalination system pervades problems such as low desalination efficiency and poor corrosion resistance. Based on our preliminary study (i.e., apply hydrophilic modification on the surface of distillation desalination tube can effectively improve desalination efficiency), this paper introduces a composite functional coating with the micro-arc oxidation (MAO) coatings sealed with hydrophilic organic coating-TiO2 hybrid sols (OT-MAO) by sol-gel process. Through contact angle measurement, scanning electron microscopy (SEM) and potentiodynamic polarization test to analyze and compare the performance of hydrophilicity and corrosion resistance of the MAO coatings and the OT-MAO composite coatings in high temperature seawater environment. The corrosion mechanism of the OT-MAO composite coatings was analyzed by electrochemical impedance spectroscopy (EIS). The results show that the OT-MAO composite coatings in high temperature seawater has much better hydrophilicity and corrosion resistance than the MAO coatings. This paper provides theoretical and technical reference for developing a new type of surface modified distillation desalination tube.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 517
Author(s):  
Bin Sun ◽  
Lei Cheng ◽  
Chong-Yang Du ◽  
Jing-Ke Zhang ◽  
Yong-Quan He ◽  
...  

The atmospheric corrosion behavior of a hot-rolled strip with four types (I–IV) of oxide scale was investigated using the accelerated wet–dry cycle corrosion test. Corrosion resistance and porosity of oxide scale were studied by potentiometric polarization measurements. Characterization of samples after 80 cycles of the wet–dry corrosion test showed that scale comprised wüstite and magnetite had strongest corrosion resistance. Oxide scale composed of inner magnetite/iron (>70%) and an outer magnetite layer had the weakest corrosion resistance. The corrosion kinetics (weight gain) of each type of oxide scale followed an initial linear and then parabolic (at middle to late corrosion) relationship. This could be predicted by a simple kinetic model which showed good agreement with the experimental results. Analysis of the potentiometric polarization curves, obtained from oxide coated steel electrodes, revealed that the type I oxide scale had the highest porosity, and the corrosion mechanism resulted from the joint effects of electrochemical behavior and the porosity of the oxide scale. In the initial stage of corrosion, the corrosion product nucleated and an outer rust layer formed. As the thickness of outer rust layer increased, the corrosion product developed on the scale defects. An inner rust layer then formed in the localized pits as crack growth of the scale. This attacked the scale and expanded into the substrate during the later stage of corrosion. At this stage, the protective effect of the oxide scale was lost.


Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 251
Author(s):  
Jijia Zhang ◽  
Jihu Wang ◽  
Shaoguo Wen ◽  
Siwei Li ◽  
Yabo Chen ◽  
...  

In this paper, an environmentally friendly waterborne polyurea (WPUA) emulsion and its corresponding coating were prepared, which was characterized by dynamic light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM). To improve the performance of the coating, we doped sulfonated graphene (SG) into WPUA to prepare composite coating (SG/WPUA). SG can be uniformly dispersed in WPUA emulsion and is stable for a long time (28 days) without delamination. The water resistance of the composite coating with 0.3 wt.% SG nanofiller was improved; the water contact angle (WCA) result was SG/WPUA (89°) > WPUA (48.5°), and water absorption result was SG/WPUA (2.90%) < WPUA (9.98%). After water immersion treatment, SEM observation revealed that the SG/WPUA film only generated enlarged microcracks (100 nm) instead of holes (150–400 nm, WPUA film). Polarization curves and electrochemical impedance spectroscopy (EIS) tests show that SG nanosheets with low doping content (0.3 wt.%) are more conducive to the corrosion resistance of WPUA coatings, and the model was established to explain the mechanism.


2021 ◽  
Author(s):  
Ziqi Zhang ◽  
Xiang Ni ◽  
Kaida Yao ◽  
Siqi Zhang ◽  
Yang Liu ◽  
...  

Enhance the antibacterial and anti-corrosion property on the premise of minimizing the biocompatibility loss of titanium implants.


Sign in / Sign up

Export Citation Format

Share Document