Corroded Metal Surfaces Research Articles

Investigation of airborne nanoparticles emitted during the laser cleaning process of corroded metal surface

Laser surface cleaning is a promising surface-cleaning technique owing to its numerous benefits, including its noncontact behavior, ease of control, high precision, and no secondary waste generation. However, it cannot prevent airborne nanoparticle emissions during the laser cleaning process. Therefore, the effects of laser-cleaning parameters on airborne nanoparticle generation are analyzed to design potential remediation methods. In this study, the nanoparticles released during the laser cleaning of corroded 304L stainless steel surfaces were investigated. Electrical low-pressure impactor analysis and electron microscopy were conducted to determine how laser parameters influenced the size and amount of emitted nanoparticles. Based on these findings, the feasibility of the filtering emitted nanoparticles using high-efficiency particulate air filters was examined.

Mitigation of hydrogen production on C-steel in HCl solution using a benzylidene compound

The mitigation influence of N 1-(4-(dimethylamino)benzylidene)-N 2-(2-((4-(dimethylamino)benzylidene)amino)ethyl)ethane1,2-diamine, (DBDB) against the corrosion of carbon steel and H2 production in 1.0 M HCl solution was studied. The experimental methods of mass loss, gasometry, potentiodynamic polarization, PDP, and electrochemical impedance spectroscopy, EIS, were utilized. The PDP data confirmed that the DBDB compound attitude is a mixed-type inhibitor. The protection efficacy rises with increasing the added amount of DBDB to reach 97% at 0.005 M concentration and 25 °C. The mitigation process was based on the adsorption of the DBDB molecules on the carbon steel obeying Langmuir’s model. Some thermodynamic functions like K ads and ΔG°ads are computed and discussed. The negative sign of ΔG°ads proves the stability of the adsorbed DBDB molecules on the corroded metal surface. The ΔG°ads values vary between −38.70 and −35.13 kJ/mol explaining the existence of both the physical- and chemisorption mixed processes. The lowering in the K ads value with temperature confirms that the adsorption of DBDB compound is favorable at lower temperatures. Theoretical quantum calculations agreed with the experimental data.

Improving the detectability and confirmation of hidden surface corrosion on metal sheets using active infrared thermography

This research aims to provide a simple approach to detecting and determining hidden corrosion using active infrared thermography with improved consistency in distinguishing hidden defect areas of metal sheets (galvanized steel and stainless steel) commonly used as part of building envelopes. Early studies on detecting hidden defects focused primarily on defects resulting from material loss. Equally important is the early detection of corroded metal surfaces hidden from the observer's plane of view through non-invasive means. In this study, two heating configurations using portable heaters were explored, along with two analysis approaches to aid in detecting and confirming the presence of hidden corroded surfaces. Metal sheets with or without hidden surface corrosion are detected, distinguished, and confirmed by observing differences in their mean surface temperatures and temperature distribution. The detection and confirmation involve two simple analysis approaches: (1) observing the differences in mean surface temperature and visual thermal contrast of the non-corroded surface available for monitoring during the heating-cooling cycle; and (2) comparing the distribution of temperature probability at a given temperature. The new method is considerably more practical as it would require only heating the region of interest to a temperature of no more than 70 °C using a portable heat source and detailed analysis requiring temperature distribution between 40 and 70 °C. The results from the detection and confirmation approaches also conform with basic principles of heat transfer, making the detection and analysis method not only practical but also scientifically sound. This method may potentially be adopted in building surveys, early detection, and post-monitoring of hidden corroded surfaces that may impact building envelope deterioration and structural integrity.

Corrosion Analysis Through an Adaptive Preprocessing Strategy Using The K-Means Algorithm

Corrosion is the process of the deterioration of metals through chemical and electrochemical reactions. The early identification of high-risk areas affected by corrosion allows time for making decisions to prevent disasters that could result from the phenomenon of corrosion. In this paper, the K-means clustering algorithm is used with various color-manipulation techniques to process and segment images of corroded metal surfaces. The goal of our research is to identify corrosion patterns in images. As an experiment, an image set of corroded surfaces demonstrating various levels of corrosion was processed. In the first phase, the images were processed with the K-means algorithm and then processed with color-manipulation techniques. The results show that this process provides relevant information regarding the surface being analyzed, successfully isolating in every test case the zone or area most affected by corrosion and highlighting the dimension of the problem. Based on our results, we recommend using the HSV technique for preprocessing images if the corroded area comprises less than 50% of the image, and an average value of k = 4 and k = 8 is recommended for obtaining significant patterns. This is important because identifying these types of patterns makes it possible for experts to make decisions without submitting these corroded metal surfaces to a second or third process or to manual analysis, and thus analytical complexity is reduced regarding time, costs, and resources.

The interplay between atmospheric corrosion and antimicrobial efficiency of Cu and Cu5Zn5Al1Sn during simulated high-touch conditions

The interplay between atmospheric corrosion and antimicrobial efficiency of bare Cu and Cu5Zn5Al1Sn was studied upon exposures simulating high-touch surface conditions. The survival of the bacteria Bacillus subtilis during surface contact with Cu and Cu5Zn5Al1Sn was examined under different degrees of surface oxidation, tarnishing, wettability and copper ion release. Depending on surface conditions complete bacteria inhibition was obtained within 4 min on Cu and within 6–10 min on Cu5Zn5Al1Sn. The antibacterial efficiency increases slightly with copper release rate and is governed by complex interactions between the corroded metal surface, bacteria and extracellular polymeric substances produced by the bacteria.

Synthesis, structural analysis and corrosion inhibition application of a new indazole derivative on mild steel surface in acidic media complemented with DFT and MD studies

A great deal of consideration has been given to the development of new compounds having diverse functionality. In this report, a new indazole derivative bearing a nitro group, namely 2-(3-chloro-5-nitro-1H-indazol-1-yl) acetic acid (CNIA) was synthesized, characterized, and used as corrosion inhibitor for mild steel (MS) in 1.0 M HCl. A full characterization of the prepared compound was performed using single‐crystal XRD, FT-IR, and UV–vis measurements; its corrosion inhibition properties were experimentally evaluated by potentiodynamic polarization (PDP) curves as well as electrochemical impedance spectroscopy (EIS) measurements, and theoretically by Density Functional Theory (DFT) and molecular dynamics (MD) simulations. Scanning electron microscope (SEM) was used to examine the morphology of the corroded metal surface before and after the inhibition. The findings demonstrated that the application of CNIA significantly reduced the corrosion rates of MS. The corrosion inhibition ability of the synthesized compound was also identified at a lower concentration in all experiments, reaching a maximum of 89 % at 10−3 mol/L. The results of potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) confirmed that CNIA could be categorized as a mixed type inhibitor with an increased polarization resistance at higher concentrations. Langmuir's adsorption isotherm was found to fit the adsorption of CNIA molecules on the MS surface. SEM photographs showed obvious less-corroded morphologies in the presence of the CNIA as compared to untreated MS surface. Theoretical calculations were proposed to explain the mechanism of the inhibition effect and found that it is due to the donor/acceptor properties of the inhibitor and its parallel disposition over the steel surface. The present compound could be a promising corrosion inhibitor for mild steel in HCl solutions, and showed a corrosion inhibition property that is superior to similar compounds.

Synergistic effect of SAMs of S-containing amino acids and surfactant on corrosion inhibition of 316L stainless steel in 0.5 M NaCl solution

The corrosion inhibition performance of S-containing amino acids L-cysteine (CYS) and L-methionine (MET), as environmental friendly self-assembled monolayers (SAMs), for 316L stainless steel in 0.5 M NaCl solution at room temperature was studied by potentiodynamic polarization curves as well as electrochemical impedance spectroscopy (EIS) measurements. The property of the inhibitive molecules adsorbed on 316L steel surface was studied by FTIR spectroscopy, while the morphology of corroded metal surface was analyzed by scanning electron microscopy (SEM). The results showed that the SAMs of individual CYS and MET significantly retarded the corrosion rates of 316L steel, and the inhibitive property could be enhanced further by combined use with sodium dodecyl benzene sulfonate (SDBS) which often served as a surfactant. It was also found in all measurements that CYS always performed better than MET in corrosion inhibition property, without consideration of the assistance of the SDBS. The conclusions of potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) measurements indicated that SAMs of CYS or MET separately and in collaboration with SDBS could be classified as mixed type inhibitor. The adsorption of CYS and MET separately on 316L steel surface obeyed Langmuir's adsorption isotherm. SEM photographs showed obviously less-corroded morphologies in the presence of the SAMs compared to untreated metal surface. Based on the electrochemical measurements, type of adsorption isotherm, FTIR analysis and morphological characterization as well as the support of quantum chemical calculations, a theoretical model was proposed to explain the mechanism of the synergistic inhibition effect of SAMs of CYS and the surfactant (SDBS) for corrosion of 316L steel.

Drastic corrosive coliation of petroleum oils and the decay of metals

In the industry of petroleum oil refining industry the term of corrosion is frequently applicable regarding the several incidents because of the corrosiveness of petroleum oils due to the presence of trace corrosive compounds in such petroleum oils since the occurrences. Usually the corrosion is the results of chemical or electrochemical process of metals when it is exposing to the corrosive environment. The investigations of the impact of the organic acids, salts, elemental sulfur and the Mercaptans on the corrosion rates of seven different types of ferrous metals and the analysis of the nature of the corrosion between these materials were the objectives of the existing research. The relevant corrosive properties of two different types of selected crude oils and the chemical compositions of selected seven different types of ferrous metals were tested by the standard methods and instruments. A batch of similar sized metal coupons was immersed in both crude oil samples separately as three homogeneous metal coupons per each crude oil container. In order of after 15, 30 and 45 days from the immersion the corrosion rates of such metal coupons were determined by the weight loss method as three sets of samples while observing the corroded metal surfaces through an optical microscope. In addition, the decay of ferrous and copper from metals into crude oils while the interaction and the deductions of the initial hardness of metals were tested. As the basic investigations there were observed the relatively lower corrosion rates from stainless steels, relatively higher impact from salts on the metallic corrosion at lower temperatures, formations of FeS, Fe2O3, corrosion cracks and pitting, significant decays of ferrous and copper from some metals and the slight reductions of the initial hardness of metals after the interaction with the petroleum oils.

The influences of the crude oils on the decay of metals

Crude oils are the essential resources for the usages of industrial purposes in various forms and the refining is a key process of separating the mixture of raw crude oils. In the existing research there were expected to investigate the impact of salts, organic acids, mercaptans and elemental sulfur of crude oils on the corrosion rates of seven different types of ferrous metals in both qualitatively and quantitatively. The chemical compositions of such selected ferrous metals and the above mentioned corrosive properties of two different types of crude oils were measured by the standard instruments and methodologies. A set of similar sized metal coupons were prepared from seven different types of metals and the corrosion rates of such metals were determined by the relative weight loss method. In addition, that the corroded metal surfaces were analyzed under the microscope, decayed metal concentrations and deductions of the initial hardness of metal coupons were measured. According to the obtained results that there were observed the lower corrosion rates from stainless steels with at least 12% of chromium and nickel, higher corrosive impact from salt, formations of FeS, Fe2O3, corrosion cracks and pitting corrosion.

Production of abrasive apricot kernel shell powder/boron nitride/polyester composites for cleaning of paint and corrosion on metal surfaces

AbstractIn this study, the synthesis and characterization of abrasive polyester composite discs reinforced with apricot kernel shell (AKS) particles and hexagonal boron nitride (BN) were carried out as an alternative to the methods used to remove the surface corrosion from metallic surfaces. Polyester composites were obtained by unsaturated polyester resin as a matrix and AKSs (1%, 3%, 5% and 10% weight ratio) with 200 mesh and 1% BN as reinforcements. Kernel shells as a source of cellulose were used for increasing mechanical stability of abrasive composite discs. The structure and chemical properties of the obtained composites were characterized by Fourier transform infrared spectrometer, X‐ray spectrophotometer and SEM analysis. Their thermal properties were determined by differential thermal analysis, thermogravimetric analysis and differential scanning calorimetry. The synthesized polyester composites were molded into cylindrical discs and the corrosion and paint layer abrasive properties of these discs on different corroded metal surfaces were investigated. The hardness of the prepared abrasive polyester composites were also measured as mechanical properties. The hardness values of prepared abrasive discs were determined as 21.9, 22.1, 23.4, 24.5 and 25.9 ± 0.1 for pure PE, 1%, 3%, 5% and 10% composites, respectively. In addition, the cleaning ability of the abrasive composites on the metal surface was determined by measuring the surface roughness and the amount of peeling. As a result, it has been determined that the most suitable optimum conditions are achieved with a contribution of 10% AKS particles reinforced composite structure considering the features such as cleaned surface roughness, cleaning suitability and composite abrasion.

Preliminaries of the Decay of Metals versus Petroleum Oils

Petroleum oils are predominantly made of various hydrocarbons with trace compounds including corrosive aided compounds that basically known as the salts, organic acids and various forms of sulfur. The scope of the current research was based on the investigations of the effect of salts, organic, elemental sulfur and Mercaptans of crude oils on the corrosion rates of seven different types of ferrous metals that important in the industry of crude oil refining. As the procedure the important corrosive properties of two different selected crude oils and the chemical compositions of the selected ferrous metals were analyzed by the standard instruments and methods. There were determined the corrosion rates of prepared metal coupons from selected ferrous metals with the similar dimensions after certain immersion time periods with respect to both crude oils by the weight loss method while analyzing the corroded metal surfaces through the microscope also simultaneously analyzed the decayed metallic elemental concentrations from metals into crude oils and the variations of initial hardness of the metals. As the foremost outcomes of the existing analysis there were obtained the significantly lower corrosion rates from stainless steels which are having at least 12% of chromium with sufficient amount if nickel, relatively higher corrosive impact from salts especially at the lower temperatures, formations of ferrous sulfides, ferrous oxides, corrosion cracks and pitting corrosion, significantly decay of copper from Monel metal, higher decay of ferrous from some of carbon steels and slight reductions of the initial hardness of metals after the formations of the corrosion on the metal surfaces.

Study on the effect of different types of crude oils on the rate of corrosion and the properties of some selected ferrous metals

Crude oil is a predominant natural resource and also it causes the metallic corrosion in the industry of crude oil refining due to some corrosive properties of crude oils. In the current research, it is expected to investigate the effect of such compounds of crude oils on the rate of corrosion of seven different types of ferrous metals which are frequently used in the crude oil refining industries. The sulfur content, salt content, acidity, and mercaptans content of each crude oil are determined in order to use XRF analyzer, salt analyzer, and titration methods. A set of equal size metal pieces are immersed in both crude oils separately for 15, 30, and 45 days and their corrosion rates are determined by using relative weight loss after these time periods while observing the corroded metal surface under the optical microscope, and the dissolved metal concentration in each crude oil sample is tested by the AAS. The hardness of each metal piece is tested before and after the immersion in crude oil with the aid of Vicker’s hardness tester. It is found that a higher amount of sulfur, acidity, and mercaptans and lower amount of salt present in Das blend than Murban. We have found there is some significant rate of corrosion from most of the metals and higher amount of dissolved metallic concentration in samples of both crude oils with respect to those metals. It is observed that there is a slight reduction in hardness of all metal pieces due to the corrosion.

An experimental study of the corrosion Process of metals in virtue of crude oils and the characteristics

Crude oils are dominant earth resources since composed with large number of hydrocarbons and some of trace compounds especially with corrosive compounds such as sulfur compounds, naphthenic acids and salts. In the current research the major scope was the investigations of the impact of such corrosive compounds on the corrosion of seven different types of ferrous metals in both qualitatively and quantitatively. According to the methodology such corrosive properties of two different types of selected crude oils were analyzed and the chemical compositions of seven different types of selected ferrous metals were detected by the standard methodologies and recommended instruments. The corrosion rates of such metals were determined by the relative weight loss method after certain immersion time periods in both crude oil samples while analyzing the corroded metal surfaces through a microscope. In addition that the decays of metallic elements from metals into crude oil samples were measured and the variations of the initial hardness of metals after the corrosion were measured by Vicker’s hardness tester. Basically there were observed the lower corrosion rates from stainless steels mainly with at least 12% of chromium and sufficient amount of nickel, higher progress of salts on the metallic corrosion at the normal temperatures while comparing with other corrosive compounds, formations of FeS, Fe2O3, corrosion cracks and cavities on the metal surfaces, decay of ferrous and copper from most metals while the immersion into crude oils and small and some insignificantly deductions of the initial hardness of metals.

THE STRENGTH OF CORROSIVE PROPERTIES OF CRUDE OILS ON FERROUS METALS

Crude oil is an unrivaled earth resource for the most of industrial applications. In the refining process of crude oil, ferrous metals play a severe role against the harsh environment while confronting adverse influences of crude oils such as the corrosion of ferrous metals. The formation of metal oxides, sulfides, hydroxides or any compound related with carboxylic group on the metal surface is known as the corrosion also mainly depends on the sulfur content, acidity, salt content and mercaptans content of relevant crude oils as well as the chemical composition of the metal. In this research it was expected to speculate the effect of such corrosive properties of Murban and Das Blend crude oils on seven different types of ferrous metals which are used in crude oil refining industry of Sri Lanka. The sulfur content, salt content, acidity and mercaptans content of each crude oil were determined by the succession of XRF analyzer, analyzer of salt and titration methods. A range of similar sized pieces of seven different types of ferrous metals were immersed in both crude oils separately and their corrosion rates were determined after 15, 30 and 45 days from the immersion by the weight loss method while observing the corroded metal surfaces under the optical microscope. The metallic concentrations in both crude oil samples after the experiment were tested by the AAS. It was found that the higher content of sulfur, acidity, mercaptans and lower content of salt in the Das blend than the Murban. According to the corrosion rates of metals, four types of metals showed higher rate of corrosion in Murban while other metals are showing higher corrosion rate in Das blend also higher metallic concentrations were obtained from Murban crude oil samples than Das Blend crude oil samples in the analysis of the AAS.

Study of the Effect of Crude Oils on the Metallic Corrosion

Corrosion is a severe matter regarding the most of metal using industries such as the crude oil refining. The formation of the oxides, sulfides or hydroxides on the surface of metal due to the chemical reaction between metals and surrounding is the corrosion that highly depended on the corrosive properties of crude oil as well as the chemical composition of ferrous metals since it was expected to investigate the effect of Murban and Das blend crude oils on the rate of corrosion of seven different ferrous metals which are used in the crude oil refining industry and investigate the change in hardness of metals. The sulfur content, acidity and salt content of each crude oil were determined. A series of similar pieces of seven different types of ferrous metals were immersed in each crude oil separately and their rates of corrosion were determined by using their relative weight loss after 15, 30 and 45 days. The corroded metal surfaces were observed under the microscope. The hardness of each metal piece was tested before the immersion in crude oil and after the corrosion with the aid of Vicker’s hardness tester. The metallic concentrations of each crude oil sample were tested using atomic absorption spectroscopy (AAS). The Das blend crude oil contained higher sulfur content and acidity than Murban crude oil. Carbon steel metal pieces showed the highest corrosion rates whereas the stainless-steel metal pieces showed the least corrosion rates in both crude oils since that found significant Fe and Cu concentrations from some of crude oil samples. The mild steel and the Monel showed relatively intermediate corrosion rates compared to the other types of ferrous metal pieces in both crude oils. There was a slight decrease in the initial hardness of all the ferrous metal pieces due to corrosion.

A customised atmospheric pressure plasma jet for conservation requirements

In the last years atmospheric plasma has gained an increasing interest in the field of Cultural Heritage. Isolated experimentations that yet generated interesting results have drawn the attention of a wider community working on coating removal, oxide reduction and sterilization applications. Thanks to this growing multidisciplinary interest, the EU funded in 2011 the PANNA project, which includes the atmospheric plasma as a novel cleaning tool for cultural heritage. Plasma cleaning has some advantages compared to standard techniques because it avoids the use of solvents, it is contactless and differently from laser it works through a surface chemical action and not with mechanical shock or local heating. Moreover, atmospheric plasma has already shown good results in reducing mode for the conversion of corroded metal surface layers and in oxidation mode for biological cleaning and organic layer removal.In order to fulfil the Cultural Heritage requirements a novel plasma torch has been developed with a new design which allows to overcome the actual limits of commercial atmospheric plasma devices. The new device permits fast and effective treatments at temperatures lower than 50 °C, even at room temperature, without any electrode material deposition. These performances will be presented in relation to the removal of epoxy coatings and daguerreotype cleaning as examples.

Corrosive Behaviors of Crude Oils and their Effects on Ferrous Metals

Crude oil is an essential natural resource regarding the day today industrial applications within adverse experiences on some materials such as the corrosion on metals which is usually known as the formation of metal oxides, sulfides or hydroxides on the metal surface itself. In the current research there were considered the effect of elemental sulfur, mercaptans, organic acids and salts on the corrosion rates of seven different types of ferrous metals. The chemical compositions of ferrous metals were detected by XRF detector. Such corrosive properties of both crude oils were tested by standard methods and adequate instruments. A set of equal sized metal coupons from each metal type were immersed in both crude oils separately and the corrosion rates of each type of metal was determined in order to 15, 30 and 45 days from the immersion by the weight loss method while observing the corroded metal surfaces through an optical microscope. The initial hardness and the hardness after corrosion on each metal coupon were tested by Vicker’s hardness tester and the both ferrous and copper concentrations in each crude oil sample were tested by atomic absorption spectroscopy after the interaction with metals. According to the results there were observed strong corrosive tendency from Das Blend crude oil than the Murban crude oil. There were found relatively higher corrosion rates of carbon steels, relatively lower corrosion rates of stainless steels and intermediate corrosion rates form Monel in both crude oils. Most of metals showed some higher corrosion rates in Murban crude oil than the corrosion rates of the same metal in Das Blend crude oil eventually.

Biofilm forming microorganisms on various substrata from greenhouse of Botanical Garden “Jevremovac”

Diversity of subaerial biofilm forming cyanobacteria, algae and fungi was investigated on 10 different substrata from greenhouse of Botanical Garden ?Jevremovac?. Out of 37 documented taxa, 16 cyanobacterial and 10 algal taxa were identified. Remaining 11 taxa belong to the Kingdom of Fungi. The highest diversity of biofilm forming microorganisms, a total of 24 taxa, was detected on the corroded metal surface, while significantly lower number of taxa was recorded on other examined substrata. Cyanobacterium Porphyrosiphon sp., diatom Achnanthes sp. and green algae Chlorella sp. and Chlorococcum minutum were the most frequently encountered photosynthetic components of biofilms. In all analyzed samples, Trichoderma sp., followed by Cladosporium sp. and Rhizopus stolonifer, were the most frequently identified fungi.

Deposit Build-up and Corrosion in a Copper Flash Smelting Heat Recovery Boiler

The aim of the work was to improve the understanding of deposit formation and corrosion in a copper flash smelting plant, focusing on the effects of process gas temperature (400–900 °C) and heat-transfer surface temperature (160–320 °C) on deposit formation and corrosion rate. The rate of build-up increased as a function of process gas temperature, which was explained by a larger extent of sintering at higher temperatures, resulting in slagging and thus, in better adhesion of particles hitting the surface. The corrosion rate increased as a function of process gas temperature. Iron sulphate (FeSO4 or Fe2(SO4)3) was found at the interface between the deposit and the corroded metal surface, suggesting that corrosion was induced by sulphuric acid (H2SO4) from the reaction between SO3 (originating from SO2 in the process gas) and water vapour.

Investigation on eddy current pulsed thermography to detect hidden cracks on corroded metal surface

This paper explores the feasibility of eddy current pulsed thermography (ECPT) to detect hidden cracks on corroded metal surface without removing the corrosion layer. The detection mechanisms are analyzed by using electromagnetic and heat conduction theories. Experiments are conducted on a metallic bar with three hidden cracks and the validity of ECPT is verified with the analysis of IR images and thermal responses. In order to further improve the detection sensitivity of ECPT, the principal component analysis (PCA) is applied to enhance the features of hidden cracks in the raw IR images by eliminating the effects of uneven corrosion and non-uniform heating. It is found that ECPT combined with PCA provides a convenient and effective way to detect hidden cracks on corroded metal surface.