Corrosion Prevention Methods Research Articles

A Novel Predict Corrosion Rate Model Based on RBFNN

Predication Corrosion rate is quantitative method by which the effectiveness of corrosion control and prevention techniques can be evaluated and provides the feedback to enable corrosion control and prevention methods to be optimized. In this paper, a novel Model to predict corrosion rate based on RBFNN was proposed. A model is produced from experimental work for one year and eighty four specimens were used through this work using anode with a high level of precision. Learning data was performed by using a 36 samples test with different Environment Resistivity (ER), Impressed Current (IC), Location of Anode (LA), Corrosion Current (CC) and Corrosion Rate (CR). The RBFNN model has five input nodes representing the (ER, IC, CC, LN, and SA), sixteen nodes at hidden layer and one output node representing corrosion rate (CR). Simulation test use 6 data samples taken from the experimental results to check the performance of the neural network on these data and shows the proposed model can be use successfully to predicate the corrosion rate.

亜鉛めっき鋼板上のチオール自己組織化超薄膜の耐食性と皮膜構造

Thiol self-assembly super thin films have attracted attention from the viewpoint of surface design, e.g. chemical sensors, molecular devices and corrosion preventive films at a molecular level. On the other hand, chromate coatings on zinc coated steel sheets have been widely applied as an economical method of corrosion prevention. In response to recent environmental regulation, e.g., RoHS Directives, chromate-free coatings have been developed and applied to electrical appliances. However, a thinner chromate-free coating is required for the purpose of obtaining a better electro-conductivity, which influences the electromagnetic shielding performance of digital electrical appliances. In this paper, the corrosion resistance and film structure of alkane- and triazine- thiol self-assembly super thin layers on zinc coated steel sheets were investigated. The mechanism of corrosion prevention by the thiol layers was discussed in order to obtain a new design concept of thinner chromate-free coatings with high corrosion resistance. The alkanethiol layers showed high water-repellency and poor corrosion resistance, and the triazinethiol layers with three thiol groups per molecular showed relatively poor water-repellency and excellent corrosion resistance in spite of very small thickness such as a few monolayer thickness, which result from suppressing oxygen reduction reaction according to electrochemical measurement. It was found from XPS analysis that alkanethiol molecules combined to Zn form layers without decomposition, and triazinethiol molecules combined to Zn and the part of these molecules decomposed to form a new network structure.

AVALIAÇÃO DA INTEGRIDADE DE RECOBRIMENTOS COMPÓSITOS DE PET COMO PROTEÇÃO CONTRA CORROSÃO EM AÇO

The serious consequences of the corrosion process have become a problem of worldwide significance. The search for alternative methods of corrosion prevention and protection represents a way to promote a sustainable development, avoiding damages in the environment. The poly (ethylene terephthalate) (PET) is an important cosntituent of urban wast, which can be recycled. PET composite coatings, are coatings with a high potential, environmentally friendly and economically viable. The aim of this work is to produce PET composite coatings on steel, with glass flakes, glass powder, and zinc powder, in the concentrations of 0.1%, 1.0% and 10% (w/w). The corrosion resistance of the conjugates was evaluated using total immersion tests in sulfuric acid, salt spray tests, and electrochemical tests of potentiodynamic polarization.

Corrosion and surface chemistry of metals

Providing a carefully developed and comprehensive overview of the corrosion chemistry of metallic materials, this book covers the principal methods of corrosion prevention. It includes a systematic study of the physical chemistry of the surface supported by state-of-the-art analysis methods. The author builds a scientific foundation by developing t

Corrosion protection of oil production and refinery equipment

The review of methods of industrial equipment corrosion prevention is presented. Application of technological means using chemical reagents and surface-active substances is considered, namely dehydration and desalting of hydrocarbon products of deposits by surface-active substances – so called demulsifiers. Corrosion inhibitors and neutralizing agents for protection of condensation-refrigeration equipment and overheads of atmospheric columns are examined. The amount of reagents to be used and the process conditions were determined.

Properties of Bacterial Corrosion of Stainless Steel and Its Inhibition by Protamine Coating

We investigated characteristics of the corrosion of stainless steel specimens by bacteria and the effects of using antimicrobial coating on the surface for inhibiting corrosion. Bacillus sp. 2-A and Staphylococcus sp. 2-1 cells adhered tightly to a stainless steel SUS304 specimen, formed a microcolony or biofilm, and had highly corrosive activities. Microbially influenced corrosion (MC) was observed under or around adhering cells. However, dead cells were markedly less active than viable cells not only in corroding the specimen but also in adhering to its surface. The culture supernatant was not able to induce the corrosion of SUS304 effectively. A protamine coating on the specimen killed bacterial cells only on its surface, interfered with cell adhesion, and inhibited MC. From these results, adhesion of viable cells to the surface of a SUS304 specimen led to the outbreak of MC. Protamine was also found to be an effective substance tested for protecting the specimen from both cell adhesion and surface MC. We suggest that a protamine coating can be applied as a convenient and inexpensive corrosion prevention method.

Failure of a heat exchanger generated by an excess of SO 2 and H 2S in the Sulfur Recovery Unit of a petroleum refinery

The aim of this work is to investigate the level of damage to the heat exchanger in a Sulfur Recovery Unit (SRU) of a petroleum refinery. The by-products of oil refining are submitted to special treatment in order to meet technical specifications of corrosivity, sulfur content, acidity, formation of pollutant compounds, and color alteration. Sulfur is removed from the by-products in the form of H 2S, which is an acid gas that is sent to the SRU for sulfur production. The gases in the SRU are H 2S, CO 2, SO 2, and SO 3, which are corrosive to the mild steel equipment. The Unit is frequently forced to paralyze its activities due to the corrosion of its heat exchangers and pressure vessels, and the acid gas load is burnt causing the release of SO x into the atmosphere. The above occurs when generalized corrosion damages SRU equipment. The importance of this work is to emphasize that the leakage of acid gas and sulfur into the atmosphere is a direct result of corrosion, which causes economical and environmental damage. This study may be used to improve the control of The Claus Process and to minimize corrosion damage. The SRU does not, at present, carry out any corrosion prevention methods. The corrosion of mild steel is controlled by correct air admission to oxide H 2S, and to produce SO 2, which is the reagent in the reaction of sulfur production.

Methodology to study cost of corrosion

It is essential to have an in-depth understanding of corrosion phenomena, from both a scientific and a technological viewpoint, in order to develop strategies that minimise the costs associated with the corrosion of materials. Looked at in this way, corrosion can be seen to be not merely an economic problem. Studies of the Cost of Corrosion have been undertaken in several countries, including Japan, UK, USA, and have estimated losses to the national economy due to corrosion of up to 5% of Gross Domestic Product (GDP). This high cost stems directly from a general lack of awareness of the economic impact of corrosion, and the poor selection of protection measures. Although a definitive method to determine corrosion costs has not been established, the main methods that have been applied are the Uhlig method, which calculates corrosion related costs based on corrosion prevention methods; the Hoar method, which makes estimates in various industrial sectors, and the Input/Output method, based on an Input/Output matrix. The present study summarises the methods that have been widely used, and the results obtained in each one of the countries in which they have been applied. On this basis, a programme is proposed to estimate the costs of corrosion associated with several important industrial activities.

Evaluation of corrosion cost in some selected food and agro‐processing industries in Nigeria

PurposeBecause of the peculiar nature of food and agro‐processing industries, the industries cannot tolerate corrosion deposits in their production lines. Hence, there is the need to account for corrosion control before and during the production operations. This is more so in Nigeria where there is little or no proper accountability of corrosion cost in all production system.Design/methodology/approachThe industries investigated were grouped into: meat and meat product, dairy and milk, beverages and brewery, confectionery and agro‐processing centres. Questionnaires and interview pro forma were used to collect information from ten major factories/outlets in each category. The study involved the use of life cycle costing to assess corrosion management alternatives and to determine the annualized value of each option.FindingsAmong the corrosion prevention methods identified in the industries, greasing gave the least cost contribution (15.9 percent) to the total cost of corrosion prevention followed by painting (17.97 percent) and cleaning (66.14 percent) in that order, while the contribution of each corrosion maintenance method to the total cost of corrosion maintenance was, respectively, 13.08, 7.23, 20.73 and 58.96 percent for annual maintenance, repair, rehabilitation and wages of workers.Originality/valueThis study reveals some of the control measures commonly adopted for minimizing corrosion damage in some selected food and agro‐processing industries in Nigeria. It also investigated the cost implication of each measure and how it affects the present value of processing machineries in each industry. The results of the study have created a state of awareness of corrosion problems to stakeholders, which would encourage preventive actions.

Corrosion of the marine infrastructure in polluted seaports

Corrosion affects both fixed and mobile marine installations and equipment made from two basic engineering materials: steel and reinforced concrete. Typical cases of corrosion appear in the retaining walls of marine ports and in the floating docks of shipyards. This situation has been aggravated in recent decades by the discharge of municipal, industrial, and agricultural effluents which contain and/or produce by biological and chemical decomposition, toxic and highly corrosive components. The corrosive substances include hydrogen sulphide (H2S), oxygen (O2), carbon dioxide (CO2), ammonia (NH3) and heavy metals. In this brief review, contaminated ports are described and typical cases of marine corrosion and methods of corrosion prevention and protection are discussed.

An evaluation of corrosion prevention practices in agricultural equipment manufactured and used in Nigeria

In order to evaluate the effectiveness of the corrosion prevention practices applied to agricultural equipment manufactured and used in Nigeria, it is necessary to identify the various corrosion prevention methods and specify the contribution and the efficiency of each method to corrosion protection. This paper outlines the basic corrosion prevention methods used in practice and attempts to evaluate the effectiveness of their use in relation to agricultural service in Nigeria. The results of this study indicated the use of oils, fats, waxes and lubricants on metal parts, spraying with gasoline on corrosion‐sensitive parts constituted the majority of applied corrosion protection in industries where the equipment is manufactured and/or used. The study concluded by giving practical recommendations that are essential for improving corrosion prevention in the Nigerian agricultural industry.

Enhancement of bond strength for epoxy-coated rebar using river sand

In this paper, improvement of bond strength for epoxy-coated rebars is studied. Although the epoxy-coated rebar is well accepted as an alternative corrosion prevention method in engineering practice, it still suffers from its poor bond performance, which requires modification of design parameters such as development length and splice length. Following our previous study [Proceedings of the Third Structure Engineering Conference (1996) 651–659], it is proposed to mix the river sand in the epoxy to improve the bond strength of epoxy-coated rebar. Specimens of several sizes of river sand and sand/epoxy weight ratios were studied. The single-rebar pullout test was performed to examine the bond strength. The open circuit potential method and the linear DC polarization method were conducted for corrosion rate measurements to ensure for keeping the merit of epoxy-coated rebar, i.e. the ability of corrosion. Experimental results show that the proposed method is very promising.

A novel photoelectrochemical method of metal corrosion prevention using a TiO2 solar panel

By using a simple TiO2 solar panel connected to a steel electrode, the concept of photoelectrochemical metal corrosion prevention has been demonstrated to be feasible in utilizing solar light for corrosion inhibition.

98/00596 High-temperature corrosion prevention method for heavy oil-fueled gas turbines

98/00596 High-temperature corrosion prevention method for heavy oil-fueled gas turbines

Gel‐Filled Boots for Corrosion Protection of Shipboard Waveguide Joints

ABSTRACT The Port Hueneme Division of the Naval Surface Warfare Center (PHD NSWC) recently completed a study of corrosion prevention methods designed to protect weapon system waveguides. Due to the nature of waveguides, the connecting flange joints are highly susceptible to aqueous and galvanic corrosion. The study found that molded plastic boots filled with silicone gel provided an excellent seal and protective barrier against the marine environment, far surpassing the capabilities of previous methods, including polysulfide (Class 1 Hazardous Material) and sealing tape. In both shipboard and laboratory tests, the gel‐filled boots lowered the corrosion protection system installation costs and extended maintenance periodicity.

Development and application of high-temperature corrosion-resistant materials and coatings for advanced waste-to-energy plants

Recently, the high-efficient thermal recycle technology of waste has become an important subject all over the world. In order to complete a highly-efficient waste burning boiler that produces the steam level of 500°C/100ata, the development and application of corrosion-resistant materials for use in a severely corrosive environment are key-technology, combining with corrosion prevention methods on designing and engineering of plants. The characteristics of high-temperature corrosion factors and corrosion behavior in waterwall and superheater tubes of waste-to-energy boiler are described first in this report. Then, the current development and application of corrosion-resistant boiler tubings and high-temperature coatings used for this kind of severe corrosive condition are summarized. Many kinds of alloys containing effective elements for corrosion tubings, and also applied by the coating processes of weld overlay and metal spraying. Furthermore, investigations of corrosion mechanism and laboratory evalutation methods which have a good reproducibility of an actual boiler are strongly needed to develop new materials.

Investigation of corrosion prevention method for determination of steel structure condition

Abstract Corrosion influences the service life of building materials and accordingly the service life of whole structures. In order to avoid corrosion activity it is necessary to separate the structures from the aggressive environment. It is very important to consider the materials, structure functions, environment and adequate protection against corrosion. The investigation has been made to develop a comprehensive expert system corrosion prevention method (ES-CPM), to establish the condition of corrosion protection on structures during their service life. New types of assessment have been proposed to create a uniform assessment of corrosion protection on structures, and an optimum procedure has been developed for its maintenance. An expert system has also been developed to select a corrosion protection system during the erection of steel structures and throughout their service life.

Interactions between cathodic protection and bacterial settlement on steel in seawater

Cathodic protection (CP) is a widely utilised method of corrosion prevention in aqueous systems. There is evidence that the electrochemical changes it produces on a metal surface influence the chemistry of the water and the settlement of fouling organisms. The interaction is in both directions, and fouling organisms and their products have an influence on the CP and on calcareous deposits formed on the metal in marine environments. The studies described show that on both stainless and nonstainless steels, CP retards the development of aerobic bacterial fouling. Increasing the CP decreases the number of bacteria. Additionally, the presence of organic material affects both the current required to maintain CP and the nature of the calcareous deposits formed. The results are discussed in relation to the electrochemistry of the system.

Quantitative measures of corrosion and prevention: application to corrosion in agriculture

The corrosion protection factor (c.p.f.) and the corrosion condition (c.c.) are simple instruments for the study and evaluation of the contribution and efficiency of several methods of corrosion prevention and control. The application of c.p.f. and c.c. to corrosion and prevention in agriculture in The Netherlands is considered in detail. Attention is paid to relations between c.p.f. and c.c., the corrosion costs, possible cost savings and the applied corrosion protection scheme on farms. It is shown that the c.p.f. and the c.c. are useful expedients in a preliminary analysis of corrosion costs and possible cost savings on farms in relation to the corrosion protection methods applied. It is concluded that significant cost savings on arable farms can be derived by improving corrosion protection. No statistically significant cost savings are possible by improving corrosion protection on the dairy farms considered in this research.

Electrochemical Study of Stainless Steels in High Temperature Urea Solutions

Abstract The corrosion of stainless steels in high temperature and high pressure urea solutions was studied by electrochemical measurements together with immersion tests to elucidate the corrosion mechanism and to rationalize the corrosion prevention methods. It was demonstrated that the corrosion of stainless steel was either active region dissolution, caused by the lack of dissolved oxygen, or dissolution near the transpassive region in process fluids with sufficient oxygen. High Cr/low Ni (or Ni-free)/Mo stainless steels were readily passivated. Stainless steels with high Cr content and/or with homogeneous distribution of Cr had superior resistance to corrosion near the transpassive region. As the temperature rose, the passivation current increased. At the same time, dissolution of oxygen into the simulated process fluids was more pronounced; therefore, high temperature was not necessarily unfavorable for passivation. Ammonia content in the process fluids strongly affected the passivation current; the current increased as the NH3:H2O molar ratio fell. By comparing the environmental variables in urea plants with the obtained data, guidelines for suitable corrosion prevention methods were developed.