Corrosion Of Metal Surfaces Research Articles

Self-powered metal surface anti-corrosion protection using energy harvested from rain drops and wind

Corrosion of metal surfaces, especially ships and cultural relics, is one of the most concerns in asset protection, which costs billions of dollars worldwide each year. For the protection of metal surfaces, cathodic protection (CP) has been widely used as a primary technology. However, the application of the technology results in high energy cost and more serious environmental pollutions. In this work, a self-powered CP system for metal surface protection was designed by utilizing the energy harvested from natural rain drops and wind using a flexible triboelectric nanogenerator (TENG). The TENG power-supplying system can provide a practical energy source for sustainably driving the CP process without using an external power source. Stereoscopic microscopy, AC impedance measurements, polarization test and surface tension testing were used to verify the feasibility of self-powered CP process. Our results indicate that the flexible TENG can produce highly efficient CP system for almost all metallic structures. This work not only demonstrates a highly-simple-fabrication, great-performance and cost-effect approach to protect metal surfaces from corrosion, but also develops a new self-powered electrochemical technique for CP that can be widely used in metal cultural relics, ocean engineering, industry, transportation, and so on.

Deposition From a Sour Heavy Oil Under Incipient Coking Conditions: Effect of Surface Materials and Temperature

Fouling in vacuum tower furnaces has been a great challenge in refineries. At the elevated temperatures of these units, coke deposition is common. For sour oils, iron sulfide also accumulates in the carbonaceous deposits, arising from iron dissolved in the feed or from corrosion of metal surfaces. In this work, the combined fouling mechanism is investigated using an atmospheric tower bottom stream which contains 4.1 wt.% sulfur, and 744 wppm dissolved iron. Isothermal deposition experiments running for 6–24 hours have been carried out on a rotating cylinder in a 600-ml batch reactor, at bulk temperatures of 380–410°C and cylinder rotation speeds of 300 rpm. A ring of either carbon steel or alloy is mounted in the cylinder to serve as a corroding or noncorroding surface, respectively. After each experiment, the thickness and weight of deposit on the metal ring are determined. The compositions of deposit are characterized. The rates of deposit formation on the ring and the deposit composition are reported as functions of temperature for a number of metal surfaces. Radial profiles of deposit composition are presented. The probable fouling mechanisms are discussed, based on the present results.

Stub resonators for online monitoring early stages of corrosion

Here we demonstrate the proof-of-principle of a new type of sensor to assess effects due to corrosion of metal surfaces. The method can be applied to all situations where metals are exposed to a corrosive (fluidic) environment, including, for instance, the interior of pipes and tubes. The sensing device is based on the operating principle of a quarter wave length open-ended stub resonator. In the absence of corrosion, inner and outer conductors of the resonator are separated by a single dielectric, i.e., a fluid. Oxidation of the metal surface of inner and/or outer conductor changes the properties of the dielectric between inner and outer conductor because it introduces a dielectric permittivity that differs from that of the fluid. Additionally, corrosion affects the skin effect and the effective resistance of the corroding inner and outer conductors of the stub resonator. As a result the recorded amplitude-frequency (AF) plot shows a shift of the resonance frequency and/or a change of shape of the resonance peak(s). The two types of transmission line designs explored are coaxial and coplanar stripline (CPS). Irrespective the design, the method outlined here offers an equipment-undemanding, low maintenance and cost-efficient in-line early warning system to detect (the onset of) corrosion. The additional advantage of the system is the freedom of design as for its geometry, from coax to one embedded in printed circuit boards, both designs with hardly any constraints on the particular dimensions. Depending on the precise geometry, the sensor may be able to detect corrosion in tap water after just 1h. Experimental data (recorded after four days) are in close agreement with simulation data representing a 17μm homogeneous oxide layer.

The inhibition effects of methionine on mild steel in acidic media

Abstract The corrosion of metal surfaces causes huge financial damages to the industries annually, what has lead to an increase in the search for substances that can slow down or prevent corrosion rate. Green inhibitors which are biodegradable, without any heavy metals and other toxic compounds, are promoted. Amino acids are attractive as corrosion inhibitors because they are nontoxic. We have used methionine as corrosion inhibitor. Materials under investigation are two kind of low allow carbon steel marked as: Steel 39, Steel 44 usually applied to concrete as reinforcing bars, and manufacture in Elbasan. The inhibition effect of methionine on the corrosion behavior of low allow steel is investigated in sulfuric acid in presence of chloride ions, in form of NaCl (H2SO4 1M + Cl- 10-3M). Potentiodynamic polarization method is used for inhibitor efficiency testing. The pitting corrosion current shows that increasing concentration of the inhibitor causes a decrease in pitting current density, and inhibition efficiency increases with increasing concentration of the inhibitors.

Corrosion behavior of Cu-Ni-Ti in artificial blood plasma in presence of cholesterol

The Corrosion behaviour of Cu-Ni-Ti in artificial blood plasma in absence and presence of 50ppm and 100ppm of Cholesterol were studied by potentiodynamic polarization study and AC impedance spectra. The inhibition efficiencies of Cholesterol for the corrosion of Cu-Ni-Ti is increased with increasing concentration. Potentiodynamic polarization study shows that the corrosion of metal surface is greatly reduced with presence of Cholesterol. This may occur due to the formation of protective layer formed on the metal in presence of Cholesterol. The polarization study leads to the corrosion inhibition of Cu-Ni-Ti in artificial blood plasma in absence and presence of 50 ppm of Cholesterol and100 ppm of cholesterol is in the following decreasing order: Cu-Ni-Ti + artificial blood plasma + 100 ppm of Cholesterol > Cu-Ni-Ti + artificial blood plasma + 50 ppm of Cholesterol > Cu-Ni-Ti + artificial blood plasma The AC impedance spectra study reveals that the corrosion inhibition of Cu-Ni-Ti in artificial blood plasma in absence and presence of 50 ppm of Cholesterol and100 ppm of Cholesterol is in the following decreasing order: Cu-Ni-Ti + artificial blood plasma + 100 ppm of Cholesterol > Cu-Ni-Ti + artificial blood plasma + 50 ppm of Cholesterol > Cu-Ni-Ti + artificial blood plasma.

Effect of chlorine-based sanitizers properties on corrosion of metals commonly found in food processing environment

In order to gauge the effect of pH and chloride concentration on the corrosion of metal surfaces commonly found in a food processing environment, different metal samples (stainless steel, carbon steel, aluminum, and copper) were exposed to chlorinated and electrolyzed oxidizing (EO) water. The samples were suspended in the chlorinated and EO solutions in a way to observe corrosion on the metals completely submerged in the solution as well as above the solution’s surface. The pH and chloride concentrations of the chlorinated and EO water samples played a significant role in mass loss for all the metal samples. Increases in surface roughness were linked to pH and chloride concentrations. Metal surfaces left suspended above the solution surfaces showed greater increases in surface roughness compared to the metal surfaces completely submerged in the solutions. This data demonstrates the need for care when selecting and using a chlorine-based sanitizer in food processing environments.

Evaluation of Zinc Rich Paint (ZRP) Efficiency on Mild Steel in Seashore Environment

Exposure to humidity and salinity in atmosphere will accelerate the corrosion process of steel. Corrosion of metallic surfaces can be reduced or controlled by addition of chemical compounds to corrodent. Zinc is one of the most important components for commercial application in the corrosion protection of steel, for which it is extensively employed to coat or galvanize ferrous metallic products. In this paper is focused with directly on efficiency of ZRP coating applied on steel substrate under NaCl solution as artificial seashore environment by using Open Circuit Potential (OCP) measurements and Electrochemical Impedance Spectroscopy (EIS).

Preparation of emulsifier-free acrylate cross-linkable copolymer emulsion and application in coatings for controlling indoor humidity

Indoor humidity has an important influence on our lives. Too high relative humidity (RH > 60 %) can cause the metal surface corrosion, electrical insulation fall, material deformation and so on. On the contrary, when the moisture content is too low (RH < 40 %), it causes skin chapping, decrease in respiratory system resistance, static electricity, etc. The humidity controlling coating is a kind of composite that controls the humidity of materials. In this study, the emulsifier-free acrylate copolymer emulsion (EF-AAC) containing ketocarbonyl and carboxyl groups was synthesized and the humidity controlling coating (EF-AAC-C) was prepared by EF-AAC, adipic dihydrazide (ADH) and porous fillers. The different proportions and the contents of KPS, NaHCO3, and the effects of polymerization time and reaction temperature on the stability of emulsion were investigated. The different ratios of fillers/emulsion and ADH/diacetone acrylamide for water resistance of coatings were also studied. Moreover, the structure of emulsifier-free acrylate copolymer was characterized by FTIR and TGA techniques. The particle morphologies were measured by transmission electron microscopy and dynamic light scattering. It showed that the distribution of emulsion particle size was narrow and uniform. The properties of humidity controlling coatings were studied with particular attention to the effects of the humidity controlling. Meanwhile, the water absorption of humidity controlling coatings was up to 260 %. The humidity controlling coatings revealed excellent properties of humidity sensitivity and humidity retention because of the composite porous structure due to fillers with emulsifier-free acrylate copolymer. The mechanism of breathing water molecules in obtained coatings was suggested and the composite could be widely used as indoor coatings for controlling humidity.

Metal Surface Corrosion: A General Way to Engineering Metal Oxide Films

Metal Surface Corrosion: A General Way to Engineering Metal Oxide Films

A Novel Dynamic Electromagnetic Heating-Magnetizing Device Used for Reverse Osmosis System

A novel, environmental friendly dynamic rotating electromagnetic heating-magnetizing device is proposed, which can heat up and magnetize the low temperature feed water of reverse osmosis system. The device converts input mechanical energy into heat energy completely. The structure and operation mechanism are discussed in detail, and the mathematical model of loss is established based on fundamental electromagnetic field theory. At last, the effects of water magnetization treated by the device are introduced, which inhibits scaling on the reverse osmosis membrane surface and slows down the corrosion of metal surface.

Role of polymer complexes in the formation of biofilms by corrosive bacteria on steel surfaces

The composition of exopolymer complexes (EPCs), synthesized by the monocultures Desulfovibrio sp. 10, Bacillus subtilis 36, and Pseudomonas aeruginosa 27 and by microbial associations involved in the corrosion of metal surfaces has been studied. An analysis of the monosaccharide composition of carbohydrate components, as well as the fatty acid composition of the lipid part of EPCs, was carried out by gas-liquid chromatography (GLC). It was found that bacteria in biofilms synthesized polymers; this process was dominated by glucose, while the growth of bacteria in a suspension was marked by a high rhamnose content. Hexouronic acids and hexosamine have been revealed as a part of B. subtilis 36 and P. aeruginosa 27 EPCs. Qualitative differences were revealed in the fatty acid composition ofexopolymers in biofilms and in a bacterial suspension. It was shown that the transition to a biofilm form of growth led to an increase in the unsaturation degree of fatty acids in the exopolymers of associative cultures. The results can be used to develop methods to control microbial corrosion of metal surfaces.

Electrografting of stainless steel by the diazonium salt of 4-aminobenzylphosphonic acid

Abstract Stainless steel has been widely used in areas such as automotive, aeronautics, marine industry, biomedical. Particularly for the processes but also for many other industrial applications, the corrosion resistance of stainless steel needs to be improved. As well-known, surface functionalization with mono- and multi-layers of organic materials is a promising solution to prevent corrosion of metal surfaces and stainless steel as well. This paper concentrated on developing a simple one-step method to strongly attach an efficient organic inhibitor to stainless steel substrate. Benzylphosphonic acid has been reported to be easily grafted on stainless steel surface by electroreduction of the diazonium salt of 4-aminobenzylphosphonic acid in sulphuric acid medium at low reduction potential (−0.01 vs. (Ag/AgCl)/V). In combination with XPS measurements, electrochemical impedance spectroscopy recorded in sulphuric acid and sodium chloride solutions containing redox probes allowed us to evidence the presence of a polybenzylphosphonic acid covalently coated on the steel surface. The pristine steel and modified surfaces were further characterized by linear sweep voltammetry in order to bring out the anticorrosive ability of the polybenzylphosphonic layer. Beside protection against corrosion, an easy attachment of aryl layer onto stainless steel substrate notwithstanding the presence of many components on its surface, even the isolating one, as reported in this work contributed to enlarge the applications of diazonium chemistry for surface functionalization.

Anticorrosion Efficiency of Cetyltrimethylammonium bromide, Sodium Dodecyl Sulfate and Tx-100 on Carbon Steel in Acidic Medium

Corrosion of metallic surfaces has continued to receive attention in the scientific world and has generated much concern with regard to material loss, especially in technological activities. The scientists in the field of corrosion are relentless in seeking better and more efficient ways of combating the corrosion of metals. Mostly saline media are the main agents that lead to corrosion, localized pitting corrosion is one of the main types of such corrosions.1 In addition to the other methods of corrosion inhibition, addition of inhibitors to the corrosion environment has been employed.2 Corrosion inhibitions of materials have been the focus of research for centuries, in many cases have been well investigated, and understood.3 Corrosion of materials generally takes place in the presence of oxygen and moisture and involves two electrochemical reactions, oxidation occurs at anodic site and reduction occurs at cathodic site.4 Inhibitors are usually used to protect material surfaces against deterioration from corrosion. The different types of inhibitors,

English

Biofouling and biofilm formations are of great concern to many modern industries, including marine, food, water, mining and medical field. The shipping industry has serious problems with biofouling (complex communities of marine organisms) on most surfaces submerged in seawater. This leads to problems such as increasing water resistance, fuel consumption and microbial corrosion of metal surfaces. The primary fouling agents on aquatic surfaces exposed to light happen to be algae and diatoms, whereas fungi and bacteria follow the trend, forming a biofilm on the surface. This further attracts the crustaceans and molluscs, which are responsible for macro-fouling. Various components such as tin, arsenic, mercury, lead and copper are used as the biocides. These components are polluting the environment affecting the marine life. The paper contents the use of herbal extract as the antifouling agent and approach for quantitative estimation of the antifouling activity of the&nbsp;Curcuma longa&nbsp;extract as compare to that of tin. &nbsp; Key words:&nbsp;Antifouling,&nbsp;Curcuma longa, leaching, paint, Gleocapsa.

Surface structure monitoring with plastic optical fiber

A sensor was designed using a plastic optical fiber to study the potential of detecting structural deformities and corrosion of metallic surfaces, in particular for applications in constricted areas such as pipes. The principle of the sensor is based on the collection of scattered light reflected by the surface imperfections. Several types of metallic materials in various surface profiles and stages of corrosion have been studied. The sensor was able to determine the position of ridges on the surface and corroded regions in all cases evaluated in the study. A sensitivity of 100 mV/mm was detectable for proximity and a vertical resolution of 1 mm has been measured.

Corrosion Estimation of Stainless Steel in Nitric Acid by an Optoelectronic Instrument Based on Diffuse Light Scattering Pattern Measurement

This paper presents the design and implementation of an optoelectronic instrument for measuring corrosion of metal surfaces, based on measurement of lightwave scattering pattern. The instrument consists of a thin beam light emitting diode (LED) that illuminates a tiny spot on the metal surface, and an array of photodiodes spread over a hemispherical structure covering the surface to record the light scattering pattern. A mathematical model of light scattering by a corroded metal surface is constructed in which a newly defined corrosion factor is correlated to light scattering pattern. The corrosion factor derived from the scattering pattern gives a measure of the degree of corrosion in a scale from 0 to 100. The temporal behavior of corrosion of stainless steel samples immersed in nitric acid of various concentrations is presented graphically. A semi empirical mathematical model describing the corrosion and dissolution processes in terms of the well-known bilogarithmic laws fits very well with the experimental results. The measured corrosion factor and the corresponding roughness factor as measured by an atomic force microscope are compared to show the relation between the two.

Computational simulation of the molecular structure of some triazoles as inhibitors for the corrosion of metal surface

The density functional theory (DFT) at the B3LYP/6-31G++ (d p) basis set level, ab initio calculations using the HF/6-31G++ (d p) and semi-empirical PM3 methods were performed on four triazole derivatives used as corrosion inhibitors, namely (5-amino 1,2,4 triazole (5-ATA), 5-amino-3-mercapto 1,2,4 triazole (5-AMT), 5-amino-3-methyl thio 1,2,4 triazole (5-AMeTT), 1-amino-3-methyl thio 1,2,4 triazole (1-AMeTT)), to investigate the correlation between its molecular structure and the corresponding inhibition efficiency (%IE). Quantum chemical parameters such as the highest occupied molecular orbital energy ( E HOMO), the lowest unoccupied molecular orbital energy ( E LUMO), energy gap (Δ E), dipole moment ( μ), sum of total negative charges (TNC), molar volume (MV), electronegativity ( χ), hardness ( η), softness ( σ) and the fraction of electrons transferred from the inhibitor molecule to the metal surface (Δ N), have been calculated. Furthermore, the adsorption energies of the inhibitors with the copper (1 1 0) surface were studied using molecular dynamic (MD) method. A good correlation between the theoretical data and the experimental results was found.

Atmospheric corrosion mapping of copper surfaces from diffuse light scattering measurements by an optoelectronic sensor system

A novel light scattering technique for mapping metal surface corrosion is presented and its results on copper exposed to atmosphere are reported. The front end of the instrument is made up of a sensor module comprising a thin beam light emitting diode (LED) illuminating a small spot on the metal surface, and a matched pair of photodetectors, one for capturing the reflected light and the other for sampling the scattered light. The analog photocurrent signals are digitized and processed online by a personal computer (PC) to determine the corrosion factor defined in terms of the two current values. By scanning the sample surface using the light beam and by computing the corrosion factor values simultaneously, a three dimensional graph and a two dimensional contour map are generated in the PC using Matlab tools. The values of the corrosion factor measured in different durations of exposure to atmosphere, which obey a bilogarithmic law, testify to the validity of our mathematical model.

Effect of inhibitors on corrosion resistance of carbon steel in suspensed liquid combined fertilizer

Inhibitors against corrosion of metal surfaces in salt solutions, especially of carbon steel in reference 5% NaCl solution and in suspension fertilizer were selected. We examined a corrosion kinetics, effect of corrosion protection, and also a penetration and a corrosion depth in the presence of various inhibitors.

A Reservoir to Reduce Rust

CHEMISTRY Many coatings that effectively impede the corrosion of metal surfaces contain chromates, which pose a substantial toxicity hazard. Conversely, passive polymer coatings can be damaged, and thus allow corrosive species to penetrate through to the metal surface. A polymer coating can be augmented using sol-gel techniques to add a thin organic or hybrid film that acts as a second barrier and also improves adhesion. Such layers are even more effective when doped with active corrosion inhibitors, but, over time, the inhibitors can weaken the structural integrity of the film. An appealing solution would be to use nanometer-scale reservoirs that bind corrosion inhibitors and release them in active form upon changes in pH, light, or humidity. Shchukin et al. used layer-by-layer deposition to prepare reservoirs with pH-responsive storage and release characteristics for aluminum surface protection. They coated silica nanoparticles with alternating poly(ethylene imine) and poly(styrene sulfonate) layers that entrapped a benzotriazole inhibitor and rendered it compatible with a zirconia/silica-based sol-gel coating. Electrochemical impedance measurements revealed that the corrosion resistance of films loaded with these reservoirs was comparable to that of the undoped sol-gel film and superior to that of sol-gel films treated with free benzotriazole. When the coatings were damaged with a microneedle before the measurements, the reservoir-doped films evinced a self-healing capacity and much longer-lasting corrosion resistance. — MSL Adv. Mater. 18 , 1672 (2006).