Electrosynthesis of Poly(ortho-phenetidine) Coatings on Steel and Investigation of Their Corrosion Protection Properties

Poly(ortho-phenetidine) coatings on 304 stainless steel (304 SS) surface have been synthesized by using the galvanostatic technique. The electrosynthesized coatings were characterized by Fourier Transform Infrared Spectroscopy (FT-IR), UV-visible absorption spectrometry and Scanning Electron Microscopy (SEM). The anticorrosion performances of poly(ortho-phenetidine) coatings were examined in 0.1 M HCl medium by the electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization technique. The corrosion rate of poly(ortho-phenetidine)-coated 304 SS was found ~10 times lower than bare 304 SS and corrosion potential increased from –0.29 V for uncoated 304 SS to –0.19 V versus Ag/AgCl (3 M KCl) for poly(ortho-phenetidine)-coated 304 SS electrode. Electrochemical measurements indicate that poly(ortho-phenetidine) coating has good inhibiting properties with an efficiency of ~93% at 1.5 mA cm^–2 applied current density in acidic corrosive media. The results of this study obviously ascertain that the poly(ortho-phenetidine) has an outstanding potential to protect 304 SS against corrosion in an acidic environment.     

Corrosion Protection of Mild Steel with Polyaniline–Thiokol Rubber Composite Coatings

The anti-corrosion performance of polyaniline-thiokol rubber (PANI/TR) composite coating applied to mild steel samples in artificial brine and hydrochloric acid environments is for the first time evaluated in this paper. The PANI/TR composite -coatings on mild steel were electropolymerized in a nonaqueous solution. EDS, XPS and SEM were concurrently used to characterize the structure, as well as composition of the coating and show that the structure is favorable to the corrosion protection. Both potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) demonstrated that the PANI/TR coating outperforms PANI coating both in the adhesion to the substrate and its corrosion protection, making the free corrosion potential by about 100mV more positive. As a result, the mild steel corrosion was greatly impeded by applying PANI/TR composite conductive polymer coating.     

Zinc‐Aluminium‐Coatings as Corrosion Protection for Steel

An analysis was made to investigate the influence of the alloying of sprayed coatings on the corrosion performance in climates of practical relevance and to evaluate the optimised alloy compositions. Furthermore, the mechanism of corrosion and coating formation was evaluated. The protective effect increased up to an aluminium content of 15 and 22 wt%, respectively, with corrosion rates below 1 µm per year. Electrochemical investigations found a distinctive decrease in the cathodic reaction together with an accumulation of aluminium in per cent and a depletion of zinc. Due to the increasing concentration of aluminium within the layer and the correlated presence of inhibitive corrosion products, the cathodic reaction and therefore the corrosion of the sprayed zinc‐aluminium coatings can be increasingly eliminated.     

Adsorption and Corrosion Inhibition Behavior of Polyethylene Glycol and Surfactants Additives on Mild Steel in H2SO4

The adsorption and corrosion inhibition behaviors of polyethylene glycol (PEG) alone and in the presence of surfactants sodium dodecyl benzene sulfonate and cetyltrimethyl ammonium bromide on mild steel in 0.1 M H₂SO₄ in temperature range of 30-60 °C was investigated using weight loss method, solvent analysis of iron ions, scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDAX), atomic force microscopy (AFM) and determination of kinetic/thermodynamic parameters. The inhibition efficiency (IE) of PEG increased with increasing concentration showing a maximum IE of 86.91% at 30 °C at 25 ppm but decreased with increasing temperature. Inhibiting action of PEG is synergistically enhanced on addition of small amount of surfactants. Surface morphology of the corroded mild steel specimen as evaluated by SEM, EDAX and AFM confirmed the existence of an adsorbed protective film on the mild steel surface. The calculated thermodynamic/kinetic parameters reveal that adsorption process is spontaneous and obey Langmuir adsorption isotherm.     

Effect of Pyrrole and N-Methylpyrrole Coatings on Corrosion Resistance of Mild Steel

COATING ON THE SURFACE of metals bypolymeric materials have been widely used inindustries for the protection of this materials against ofcorrosion[1-4].Electropolymerization is an effective technique forthe surface coating of various conductive materialswith wide variety of polymers with various thick nesses[5].Recently,electropolymerization of pyrrole on steelsubstrates has been investigated with the aim ofproducing uniform and strongly adherent coatings[6-9].It was found that only lim…     

Protection of Steel Bridges From Corrosion

Abstract

Atmospheric corrosion is only one of many causes of deterioration of structures, and protective measures applied to bridges are usually successful, in the sense that disasters resulting from corrosion are rare. Most bridge steelwork requires careful protection and regular inspection and maintenance, though in certain circumstances various grades of steel can be left uncoated. Depending on the intended life of a bridge, the procedure which in the long run is the most economic is usually one which employs a high standard of initial protection, so that unnecessarily frequent repainting is avoided. The circumstances in which steel piles can safely be used to support a bridge structure are briefly discussed. The protection of superstructure steelwork begins at the design stage, when much can be done to minimise subsequent corrosion troubles. Guidance is given on the choice of protective films, with or without a preliminary coating of non-ferrous metal. The standard of surface preparation needed for each type is given and its importance emphasised. The advantages of carrying out part of the protective work at the factory are explained, and special points to be considered at joints, bearings and road decks are described.

Maintenance painting is needed between 10 and 20 times during the life of a steel bridge, and calls for careful attention backed up by regular, skilled and painstaking inspection. A good system of testing is needed, and simple tests giving quick results have distinct advantages, especially if they can be carried out at the site where painting is being done. Some actual examples of protective measures adopted on a variety of modern steel bridges are described.     

Cr添加对Ni-Cr-Mo激光熔覆层在含氯硫代硫酸盐溶液中耐蚀性的影响

通过微观结构观察和电化学测量,在硫代硫酸盐氯化物溶液中评估了Cr的添加对Ni-Cr-Mo激光熔覆涂层耐腐蚀性的影响。通过扫描电子显微镜和X射线衍射观察到了非常相似的微观结构和相组成。涂层主要有共晶和枝晶,并由包含Cr、Mo、W、Fe的γ-Ni固溶体和Cr_0.19Fe_0.7Ni_0.11固溶体组成。电化学结果表明,添加一定Cr含量的激光熔覆层表现出更好的耐腐蚀性。C28涂层表现出较高的开路电位值和较低的钝化电流密度,并且具有更大的阻抗模量和电荷转移电阻。随着Cr含量的增加,在含氯的硫代硫酸盐溶液中钝化膜的厚度变厚,膜的缺陷变少。Mott-Schottky分析表明,溶液中激光熔覆层上表面形成的钝化膜表现为n型和p型半导体。     

Processing and Development of Corrosion Resistance Surface-Active Thin Film Nanocellulose Composite Coatings for Mild Steel Protection

Protection of Metals and Physical Chemistry of Surfaces - Mild steels are applied in the construction of oil platforms and pipelines due to their ease of formability, machinability, good mechanical...     

石墨烯基防腐涂层研究进展

自石墨烯发现以来,其优异的导电性、力学性能、热导性、光学性能等吸引了研究学者的广泛关注。此外,石墨烯稳定的sp2杂化结构使其自身具有良好的化学惰性、抗氧化能力和抗渗透性,被认为是一种理想的防腐材料,在金属材料的防腐领域具有非常大的应用前景。基于此,综述了石墨烯防护薄膜和石墨烯/有机涂层在金属腐蚀防护领域的研究进展,并从分散角度阐述了石墨烯的功能化对有机涂层防腐性能的影响;同时归纳了石墨烯的高导电性对有机涂层防护性能的影响以及防护机理。最后展望了石墨烯薄膜和石墨烯有机涂层在金属腐蚀防护应用方面面临的一系列难题以及发展方向。     

Enhancement of Corrosion Protection of Steel Pipelines

The role of academician Ya. M. Kolotyrkin and his scientific school in the enhancement of the corrosion protection of main pipeline transport is illustrated by an example of the Russian fuel and energy sector. Based on the scientific achievements of the school, the requirements for complex pipeline protection, as well as the monitoring of its effectiveness, were formulated. Corrosion protection services were provided with new methods, facilities, and test equipment to make oil and gas pipelines more reliable.     

Protection of Steel Pipelines against Underground Corrosion

The problems of designing the electrochemical protection (ECP) of pipelines are considered. It is shown that the application of the same mathematical model describing the potential distribution along the pipeline allows one to minimize the error. The introduction of acceptance test of insulation by the method of cathodic polarization provides high reproducibility of rated parameters of ECP, whereas the consideration of time-variation in the protective properties of pipeline insulation enables one to determine the parameters of cathodic power sources for at least 10 years. The procedure of estimating the corrosion risk of a pipeline, taking into account eight factors affecting the corrosion, is reported.     

钢质管道内腐蚀因素和解决腐蚀防护措施

本文综述了不同环境对钢质管材腐蚀行为及腐蚀机理,对含硫条件下、含CO2以及各种因素对钢质管道的影响分别进行了阐述。重点介绍管内腐蚀的原因,并通过实验研究,提出防腐蚀的办法,为今后解决钢质管道内腐蚀提供技术参考。     

电厂钢结构腐蚀防护应用

某滨海电厂4台机组锅炉炉架及其附属钢结构在海洋大气环境中腐蚀较重，本文分析腐蚀原因，提出切实可行的解决方案，确保电厂设施正常安全运行。     

钢结构腐蚀与涂层防护

钢结构处于不稳定状态会发生腐蚀现象,采用防腐蚀涂层是最有效、最经济、应用最普遍的方法,本文介绍了钢结构发生的电化学腐蚀反应现象,目前对涂层防护机理的研究现状及评定涂层防腐性能的方法,指出涂层防护机理的深入研究,对研制性能更优的防腐蚀涂料和涂装技术具有重要指导意义。     

北大桥钢结构桥梁腐蚀防护

钢结构采用合理的涂装配套方案一长效重防腐涂装及复涂工艺是提高钢结构防腐能力的有效途径。钢梁的防腐效果是和钢梁表面处理．涂装配套、施工质量等诸多因素密切相关．     

Effect of Graphite Addition on Structure and Properties of Ti(CN) Coatings Deposited by Reactive Plasma Spraying

Ti(CN) coatings with graphite addition ranging from 0 to 50 wt.% were prepared using reactive plasma spraying technology and their microstructure, mechanical, and tribological properties were investigated using scanning and transmission electron microscopy, x-ray diffraction analysis, x-ray photoelectron spectroscopy, Vickers microhardness testing, and block-on-ring wear testing. The results showed that graphite addition resulted in crystallite size refinement and an increase in the amount of amorphous phase. The Ti(CN) coatings consisted of a mixture of Ti(CN), graphite, CN _x , and amorphous phases. The hardness first increased then decreased as the graphite content was increased, with a maximum of 1450 HV_0.2 for 30 wt.% graphite addition. The fracture toughness decreased from 4.38 MPa m^1/2 to 2.76 MPa m^1/2 with increasing graphite content. The friction coefficient decreased due to unreacted graphite embedded in the matrix. Also, the wear rate first decreased then increased, with a minimum value of 2.65 × 10^?6 mm³ N^?1 m^?1 for 30 wt.% graphite addition. The wear mechanisms of the Ti(CN) coatings included abrasive, adhesive, and oxidation wear.     

聚乙二醇分散的锌铝铬涂层在3.5%NaCl溶液中的腐蚀行为及防腐蚀机理

采用强极化、弱极化、交流阻抗以及XRD和SEM等手段,分析了聚乙二醇分散的锌铝铬涂层在3.5 %NaCl介质中腐蚀电位、腐蚀电流密度、阻抗的变化和阳极钝化情况,以及腐蚀前后的物相组成和表面形貌,研究了涂层的防腐蚀机理.结果表明:涂层在腐蚀初期存在强烈的阳极钝化,随着腐蚀的进行,钝化现象逐渐减弱;在较长时间的浸泡下,涂层对钢基体的保护效果明显.防腐蚀机理为:腐蚀前期是涂层中的锌、铝粉活性溶解产生钝化,中期是钝化膜溶解、Cr<'6+>的再钝化及锌、铝粉提供电化学保护,后期主要是涂层屏蔽作用,而屏蔽作用是涂层的主要保护作用.     

Resistance to Corrosion of Zirconia Coatings Deposited by Spray Pyrolysis in Nitrided Steel

Coatings of zirconium oxide were deposited onto three types of stainless steel, AISI 316L, 2205, and tool steel AISI D2, using the ultrasonic spray pyrolysis method. The effect of the flux ratio on the process and its influence on the structure and morphology of the coatings were investigated. The coatings obtained, 600 nm thick, were characterized using x-ray diffraction, scanning electron microscopy, confocal microscopy, and atomic force microscopy. The resistance to corrosion of the coatings deposited over steel (not nitrided) and stainless steel nitrided (for 2 h at 823 K) in an ammonia atmosphere was evaluated. The zirconia coating enhances the stainless steel’s resistance to corrosion, with the greatest increase in corrosion resistance being observed for tool steel. When the deposition is performed on previously nitrided stainless steel, the morphology of the surface improves and the coating is more homogeneous, which leads to an improved corrosion resistance.     

乙二醇对海底管道CO2腐蚀的抑制作用

海上凝析气田开发普遍采用加注乙二醇(MEG)的方法保护海底湿气管道,抑制水合物形成,对管道内腐蚀也有一定的影响。本工作采用高温高压釜和电化学方法研究了乙二醇对海底管道内部CO2腐蚀的影响,结果表明,乙二醇对CO2均匀腐蚀具有显著抑制作用,抑制效果与国外的经验公式预测结果接近。乙二醇对管道内腐蚀起抑制作用的主要原因可能与降低水的活性、降低FeCO3的溶解性、促进生成腐蚀产物膜等因素有关。