Addition Of Corrosion Inhibitor Research Articles

Electrochemical Analysis of an API X100 Steel Immersed in NACE Brine Solution with Addition of Corrosion Inhibitor

In this research the electrochemical performance of a high strength low alloy steel (HSLA) in contact with a brine solution containing a filmic inhibitor was studied. The API X100 steel was obtained through a casting of steel followed by a rolling process. The steel was microstructurally and mechanically characterized. A multiphasic ferrite-bainite morphology was found, as well as an average hardness of 209 HB after rolling, and using a correlation between Brinell hardness and tensile strength, a resistance of 104,500 Psi was determined. The steel was characterized by Electrochemical Impedance Spectroscopy (EIS) using a brine solution with 50 ppm of corrosion inhibitor like electrolyte. In the electrochemical analysis a capacitive system was obtained, which was influenced by the processes of mass transfer and adsorption, which limited the charge transfer processes. The addition of inhibitor improved the absorption processes by limiting the oxide-reduction processes

Leaching Behavior and Corrosion Inhibition of a Rare Earth Carboxylate Incorporated Epoxy Coating System.

While paint coatings act as important barriers to corrosion, defects can lead to localized, rapid metal loss. The addition of corrosion inhibitors that are capable of leaching from a coating to protect the metal surface at a defect can prevent this type of corrosion. This work investigates the release and corrosion protection capabilities of two rare earth (RE) carboxylate inhibitors from an epoxy coating as an initial step to understanding their leaching behavior and interaction with the coating system. Leaching experiments were performed via inductively coupled plasma mass spectroscopy (ICP-MS) analyses of the solutions in which free-standing coatings loaded with varying concentrations of inhibitor compounds had been immersed. Inhibitor release from the epoxy coating was observed to be dependent on initial inhibitor concentration, inhibitor chemistry, and solution pH conditions. The coating systems with greater initial inhibitor loadings showed higher leaching rates, particularly in acidic environments. Following immersion, the absence of characteristic inhibitor peaks in the FTIR spectra of the coatings also confirmed leaching had taken place. Cross-sectional views of the coatings after exposure to the pH 1 environment presented a chloride infusion zone at the coating/solution interface where the inhibitor had leached out. The RE active inhibition provided by the leached RE carboxylate inhibitors was verified by exposure of a coating defect to a chloride contaminated environment.

Effect of addition of corrosion inhibitors on corrosion behaviors of PCV material under diluted artificial seawater environment

ABSTRACT Fukushima Daiichi nuclear power plants (1F) were damaged by unprecedented severe accident in the great east Japan earthquake, and seawater and freshwater had been injected as an emergency countermeasure for the core cooling. Although, the primary containment vessel (PCV) was not supposed to be exposed to diluted seawater, the PCV will be exposed to diluted seawater environment until fuel debris removal is completed. Therefore, it is necessary to establish a countermeasure of corrosion for the PCVs made of carbon steel. In this study, the effect of the addition of corrosion inhibitor, which is one of the corrosion countermeasures, was investigated by two types of corrosion tests. As a result of the immersion corrosion test, it was found that any of the three kinds of corrosion inhibitor could suppress corrosion of carbon steel. In addition, as a result of the inhibitor interim addition test, it was found that corrosion of carbon steel covered with corrosion products could be suppressed by optimizing the additive amount of corrosion inhibitor in the cooling water.

Corrosion inhibition and friction-reduction property of tetrazole derivatives on copper

PurposeThis paper aims to evaluate the inhibitive effect and adsorption behavior of 5-(ethylthio)-1H-tetrazole (EHT) and 5-(benzylthio)-1H-tetrazole (BHT) on copper in a sulfur-ethanol system.Design Methodology ApproachEvaluation was carried out using electrochemical measurement and surface analysis techniques. Measurements of static friction coefficient by scanning electron microscopy and contact angle analysis were applied and finally confirmed the existence of the adsorbed film. The inhibitive mechanism of the two compounds was evaluated by means of quantitative calculation and molecular dynamics simulation. The friction coefficient of corrosion surface before and after adding corrosion inhibitor was determined through static friction coefficient measurements.FindingsThe electrochemical measurement indicated that the most effective concentration of two corrosion inhibitors was 70 mg L–1, while the inhibition efficiency of that was EHT > BHT. The friction coefficient data showed that the addition of corrosion inhibitor reduced the roughness of the corrosion surface. Adsorption behavior of two inhibitors followed the Langmuir’s adsorption isotherm and was attributed to mixed-type adsorption. The results of quantitative calculation and molecular dynamics simulation showed that tetrazole rings of the two inhibitors and its connected S atoms were adsorbed on Cu(111) surface in parallel.Originality ValueThe corrosion inhibition performance of two tetrazolium derivatives in a sulfur-ethanol system was studied by combining experiments with theory, which provided a theoretical basis for the future research.

Effect of polymerized ionic liquid based gel inhibitor on electrochemical performance of self-assembled nanophase coating

The corrosion process is a surface reaction that can be controlled by the addition of corrosion inhibitors, which adsorb on the reacting metal surface. The inhibitors could be applied to a metal surface in many different ways. In this contribution, influence of polymerized ionic liquid (PIL) was examined on inhibition performance of a coating using carbon steel samples. The PIL was loaded in self-assembled nanophase particle (SNAP) coating and the inhibition behaviour was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy and scanning kelvin probe techniques. The inhibition efficiency of the coating increases with the addition of PIL as observed from potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements. In addition, scanning kelvin probe (SKP) measurement provides further understanding on the strong interfacial properties of the modified coating compared to that of the SNAP.

Reaction of Chelating Agents and Catalyst with Sandstone Minerals During Matrix Acid Treatment

Chelating agents were used recently to stimulate sandstone formations in oil and gas reservoirs. Chelating agents replaced the old sandstone acidizing fluids such as mud acid (HF $$+$$ HCl). Mud acid has several problems such as high corrosion rate, reservoir unconsolidation problems, and incompatibility with the reservoir rocks. The objective of this study is to introduce different chelating agents diluted in deionized water and seawater combined with potassium carbonate as a catalyst and clay stabilizer to stimulate sandstones reservoirs. In this paper, solubility experiments were performed for Bandera and Berea sandstone rocks in high pH DTPA, ethylenediaminetetraacetic acid (EDTA), and hydroxyethylenediaminetriacetic acid (HEDTA) solutions. The optimum concentrations of both chelating agent and potassium carbonate were determined through the solubility experiments. Chelating agents were diluted using seawater and deionized water from an initial concentration of 40 wt%. Coreflooding experiments were performed on Berea and Bandera sandstone cores to assess the performance of the new formulation. Corrosion tests were conducted on actual tubing coupons made of L-80 alloy to check the corrosion rate of the new formulations. The enhancement in the core permeability was recorded after using the chelating agent and the catalyst to investigate the effectiveness of the formulation in sandstone acidizing. The solubility results showed Berea and Bandera sandstone have good solubility in HEDTA, EDTA, and DTPA chelating agents. EDTA chelating agent combined with potassium carbonate enhanced the permeability of both sandstone cores. EDTA chelating agent combined with catalyst has a corrosion rate of $$0.01\,\hbox {lbm/ft}^{2}$$ at $$350\,^{\circ }\hbox {C}$$ compared to $$0.65\,\hbox {lbm/ft}^{2}$$ for the mud acid plus 3 vol% corrosion inhibitor at the same temperature. The corrosion inhibitor additives will be eliminated in the new formulation which will reduce the cost of the stimulation fluid.

Instantaneous Impedance Analysis of Non-Stationary Corrosion Process: a Case Study of Carbon Steel in 1M HCl

The paper concerns the problem of evaluation of stationarity of carbon steel corrosion in 1M HCl. Comparison of corrosion rate with addition of corrosion inhibitor to the reference measurement is the most often used way of evaluating inhibitor efficiency. Such an approach is valid only if corrosion rate is a stationary process. Two complementary techniques were used simultaneously: volumetric analysis of evolved hydrogen and instantaneous impedance spectroscopy monitoring. Changes of the electrode surface area and chemical composition have a major impact on the dynamics of both cathodic and anodic processes. On the base obtained results, authors claim that the stationarity of the process determined most often on the base of corrosion potential is ineffective and insufficient.

Potential application of some coumarin derivatives incorporated thiazole ring as ecofriendly antimicrobial, flame retardant and corrosion inhibitor additives for polyurethane coating

Abstract Coumarin derivatives continue to draw the attention of synthetic organic chemists due to their versatile utility associated with them and their widely use as pharmaceuticals. Coumarin derivatives having various substituted thiazole rings at carbon-3 exhibit promising biological activities. In this research, two series of coumarin derivatives incorporated thiazole ring were prepared; coumarin thiazole derivative and benzo coumarin thiazole derivative, the structures of the products were confirmed by elemental analysis, FTIR, 1 HNMR and mass spectroscopy. The prepared coumarin derivatives I–III was incorporated physically into polyurethane coating as an additive. Experimental coatings were fabricated on a laboratory scale and applied by brush on steel and wood panels. The coated films were screened against gram-negative bacteria, gram-positive bacteria and fungi to evaluate the antimicrobial activity of the prepared coumarin derivatives. A flame retardant property, the corrosion resistance and the mechanical properties of these coated films were also examined to evaluate the drawbacks of the prepared coumarin derivatives as an additive. The obtained results showed that, the incorporation of a few amount of the prepared coumarin derivatives into polyurethane coating have led to improve the antimicrobial activity, flame retadancy, corrosion resistance, gloss and scratch hardness of the polyurethane coated films.

Determination of Naphthenic Acid Number in Petroleum Crude Oils and Their Fractions by Mid-Fourier Transform Infrared Spectroscopy

Naphthenic acid is a generic name used for all the organic acids present in crude oils. The quantitative determination of naphthenic acid number (NAN) is an essential parameter for petroleum refineries to evaluate corrosive properties of crude oils prior to their processing. Currently, most of the refineries are using total acid number (TAN) as a measure of corrosivity of crudes during their selection, valuation, and processing. Some of the organic molecules are being used as corrosion inhibitors to reduce corrosion in refinery process units, and the dosage of the same depends on the total acid number as it has been understood from the studies that acid inhibitors form a protective layer on the surface of the pipes and thus reduces the corrosion due to acids present in crude oil. TAN measurement by titration overestimates the acid number as each and every molecule like thiols and phenols etc. that are titratable by alkali are also included in the calculation and that causes the improper estimation of the addition of corrosion inhibitors. To get a better refinery margin in the present economic scenario, optimization of the addition of corrosion inhibitors is very much essential and thus accurate measurement of NAN is a primary concern. Hence, we present a quick and efficient mid-Fourier transform infrared (FTIR) spectroscopic method for the determination of NAN using a variable path length liquid cell with calcium fluoride windows. Two distinct photon absorption bands in the region of 1680 to 1800 cm–1 were observed during the spectral measurement and are due to the formation of monomeric and dimeric forms of carbonyl (C═O) group of carboxylic acids, and hence both are considered for the quantification. The method is applicable even to highly volatile crude oils that are not measurable by the normal attenuated total reflectance (ATR)-FTIR technique. This article also presents the effect of solvents, hydrogen bonding, formation of monomer and dimer, etc. Currently, this method is being applied for the determination of NAN for crude oils and straight run vacuum gas oil (VGO) samples as they contain either negligible or no carbonyl compounds other than carboxylic acids that interfere in the region of interest.

Adsorption and Corrosion Inhibition Behaviour of Some N-{n-[1-R-5-(quinoxalin-6-yl)-4,5-Dihydropyrazol-3-Yl]Phenyl}Methanesulfonamides on Mild Steel in 1 M HCl (n = 2, 3, 4; R = propanoyl, methylsulfonyl): Experimental and Theoretical Studies

Mild steel (MS) is a material of choice for diverse structural and industrial applications owing to its excellent mechanical strength and relatively low cost [1]. Certain requisite industrial activities involve the use of acidic solutions that constitute strong corrosive environment for MS. Therefore, corrosion of MS causes great economic loss and present huge safety threats to the concerned industries. Addition of corrosion inhibitors to aggressive solution has been identified as an economical and practical means of controlling metal corrosion. The existing data have shown that organic compounds containing O, N, S, and P heteroatoms, and pi-electron or aromatic systems often exhibit good anticorrosion properties [2,3]. Quinoxaline derivatives possess these features and their corrosion inhibition properties have been reported. These compounds form parts of many essential biological and pharmaceutical compounds and fit into the class of environmentally benign inhibitors [3]. In the present study, adsorption and corrosion inhibition properties of six quinoxaline derivatives namely, N-{n-[1-R-5-(quinoxalin-6-yl)-4,5-dihydropyrazol-3-yl]phenyl}methanesulfonamides: R = propanoyl & n = 2, 3, 4 for MS-2-PQPP, MS-3-PQPP, and MS-4-PQPP respectively; and R = methylsulfonyl & n = 2, 3, 4 for MS-2-PQPMS, MS-3-PQPMS and MS-4-PQPMS were investigated on MS in 1 M HCl solution. The techniques employed in the study include potentiodynamic polarization and electrochemical impedance spectroscopy. Quantum chemical calculations and molecular dynamic simulations studies were used to support experimental results. All the studied compounds were found to exhibit appreciable inhibition efficiency and they are all mixed type inhibitors. The compounds inhibit MS corrosion by adsorbing on the steel surface and geometrically blocking the active sites for the corrosion reaction. Both MS-3-PQPP and MS-3-PQPMS showed higher inhibition performances, which suggests that the interplay of electronic and steric effects of the carbonyl/methylsulfonyl substituents ensures higher inhibition performance when n = 3 (meta-substitution). The adsorption of the studied compounds obeyed the Langmuir adsorption isotherm model. Theoretical quantum chemical calculations and molecular dynamic simulations corroborate experimental results. References (1) De la Fuente, D.; Diaz, I.; Simancas, J.; Chico, B.; Morcillo, M. Corros. Sci. 2011, 53, 604. (2) Mashuga, M.E.; Olasunkanmi, L.O.; Adekunle, A.S.; Yesudass, S.; Kabanda, M.M.; Ebenso, E.E. Materials 2015, 8, 3607. (3) Olasunkanmi, L.O.; Obot, I.B.; Kabanda, M.M.; Ebenso, E.E. J. Phys. Chem. C 2015, 119, 16004. Figure 1

Ammonium molybdate added in hybrid films applied on tinplate: Effect of the concentration in the corrosion inhibition action

One of the ways to improve the anticorrosive properties of the hybrid films is with the addition of corrosion inhibitors based on inorganic salts. The protection mechanism involves the release of molybdate ions inserted in coatings by sol–gel during the immersion in the electrolyte, thereby minimizing the corrosion process. Siloxane–PMMA hybrid films are constituted by a silica network, to which the chains of poly (methyl methacrylate) (PMMA) are connected by covalent bonds (Class II) or by physical interactions (Class I). The stability and transparency enable the application of these materials in the coating of tinplate packagings in order to enhance corrosion resistance and reduce the brittleness of these products. In this context, the objective of this study is to coat the tinplate with a hybrid siloxane–PMMA (Class II) film obtained from a sol constituted of the alkoxide precursors: 3-(trimethoxysilylpropyl) methacrylate (TMSM), poly(methyl methacrylate) PMMA and tetraethoxysilane (TEOS), by varying the added corrosion inhibitor concentration from 0.01 to 0.02M. The films were obtained by a dip-coating process and characterized according to their morphological and electrochemical behavior. The results showed that hybrid films doped with corrosion inhibitors showed an increase in the layer thickness in comparison to the inhibitor-free film. Furthermore, the addition of a higher concentration of ammonium molybdate resulted in an increase of the corrosion performance of the hybrid films.

Electrospun protective self‐healing coatings for light alloys: A better understanding of the intrinsic potential of the technology

ABSTRACTPolymeric coating systems exhibit high potentiality to provide an effective barrier against corrosion of metallic surfaces. However, these coatings can lose their protective characteristics because of their high susceptibility to damage. Thus, the addition of corrosion inhibitors is desirable and considered as an alternative route for active corrosion protection. In the present work, eco‐friendly electrospun coatings of poly(vinyl alcohol) (PVA) loaded with cerium salts have been deposited onto aluminium 6082 alloy. Two different precursors of cerium (III) (i.e., cerium nitrate and cerium acetylacetonate) were added to the electrospinning solutions and the effectiveness of the resulting nanofibrous coatings was evaluated for the healing of generated defects. The microstructural features of the electrospun coatings have been investigated by scanning electron microscopy, infraredspectroscopy, and thermal analysis. Tensile tests were performed to assess the mechanical properties of the different fibrous coatings. The electrochemical behavior of both intact and damaged coatings was evaluated in 3 wt % NaCl solution by means of electrochemical impedance spectroscopy. All the deposited PVA coatings loaded with cerium(III) salts showed remarkable corrosion resistance. In the case of artificially damaged coatings, a self‐healing effect, which stops the development of the corrosion process and provides a significant recovery of the corrosion resistance, has been observed only for coatings loaded with cerium III acetylacetonate. The release of cerium from damaged PVA fibers has been demonstrated by means of inductively coupled plasma mass spectrometry. The observed self‐healing effect has been ascribed to the formation of cerium hydroxide on the defective zone, which hindered the corrosion process. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42728.

Evaluation of corrosion inhibitors in acid medium

Purpose – The purpose of this paper is to evaluate the corrosion inhibitor performance in acid medium through the determination of Fe2+ ions present based on reaction kinetics of steel with the acid. The use of corrosion inhibitors has been an excellent technique for protecting carbon steel pipes acidizing operations in oil wells. The inhibitor forms a chemical barrier on the metal surface that prevents or reduces attack by the acidic media. Design/methodology/approach – The experimental study provides a methodology to evaluate the performance of corrosion inhibitors in an acid medium, preferentially of concentrated hydrochloric acid. The process consists essentially of total immersion coupons of carbon steel, with continuous stirring, controlled temperature and quantitative determinations of iron ions from the dissolution of steel. The additions of commercial corrosion inhibitor base of ethoxylated amines of high molecular weight in an acid medium showed excellent performance at a temperature ranging from 25 to 45°C. Findings – This paper presents the mechanisms of protection, performance graphs and calculations of the activation energies of the addition of corrosion inhibitors in an acidic medium. Originality/value – The originality of this essay is to evaluate and correlate the performance of corrosion inhibitors with the activation energy in experimental conditions.

Multifunction Nanostructured Coatings

The active corrosion protection of metallic substrates can be achieved by addition of corrosion inhibitors to protective coatings. However, direct mixing of an inhibitor with coating formulations can lead to important drawbacks decreasing barrier properties of the coating and diminishing activity of the inhibitor. Also, soluble inhibitors can cause phenomena like osmotic blistering or be leached out spontaneously to the environment, which limits long-term performance and is environmentally pernicious. To overcome this problem and have controlled release of inhibitor different strategies of inhibitors storage in nanocontainers have been developed in order to produce smart self-healing coatings. In this work novel protective nanostructured coatings with self-healing ability are presented. This effect is obtained on the basis of nanocontainers that release entrapped corrosion inhibitors in response to local pH changes or presence of corrosive species. The development of new nanocontainers for organic and inorganic corrosion inhibitors achieved is described, especially the most promising from industrial point of view, based on Layered Double Hydroxides (LDH). The combination of different of these nanocontainers in the same coating system has proved to be effective to accomplish further functions as antifouling and sensing.

Material removal mechanism of copper chemical mechanical polishing in a periodate-based slurry

The material removal mechanism of copper in a periodate-based slurry during barrier layer chemical mechanical polishing (CMP) has not been intensively investigated. This paper presents a study of the copper surface film chemistry and mechanics in a periodate-based slurry. On this basis, the controlling factor of the copper CMP material removal mechanism is proposed. The results show that the chemical and electrochemical reaction products on the copper surface are complex and vary considerably as a function of the solution pH. Under acidic conditions (pH 4) the copper surface underwent strong chemical dissolution while the corrosion was mild and uniform under alkaline conditions (pH 11). The corrosion effect was the lowest in near neutral solutions because the surface was covered with non-uniform Cu(IO3)2·H2O/Cu-periodate/copper oxides films, which had better passivation effect. The surface film thickness and mechanical removal properties were studied by AES and AFM nano-scratch tests. Based on the combined surface film analysis and CMP experiment results, it can be concluded that the controlling factor during copper CMP in a periodate-based slurry is the chemical-enhanced mechanical removal of the surface films. The periodate-based slurry should be modified by the addition of corrosion inhibitors and complexing agents to achieve a good copper surface quality with moderate chemical dissolution.

Effect of Corrosion Inhibitor on the Compressive Strength of Polymer-Modified Cement Mortars

This study examined initial flow and compressive strength development of polymer-modified cement mortar according to the addition of corrosion inhibitor. Test results showed that with the increase of the amount of corrosion inhibitor, the initial flow of mortars increased whereas compressive strength decreased. The strength development of mortar specimens could be reasonably predicted using the modified ACI 209 equations.

PERFORMANCE OF BLENDED CORROSION INHIBITORS FOR REINFORCED CONCRETE

Use of chemical corrosion inhibitors has been recognized as one of the effective way of controlling rebar corrosion in reinforced cement concrete (RCC). Corrosion inhibiting admixtures fall into the specialty admixture category and are used to slow down corrosion of reinforcing steel in concrete. The addition of corrosion inhibitors to the mix, offers a viable corrosion protection measure. There are generally three groups of inhibitors: anodic, cathodic and mixed inhibitors. The effect of these chemicals on various physical properties of cement such as setting time, pH, and compressive strength needs to be explored before use. In the present investigation an attempt has been made to mix two commercially available corrosion inhibitors and evaluate its effect on setting time, pH and compressive strength. In the next part of the study electrochemical test involving the blended chemical corrosion inhibitor were also conducted on RCC slab specimen. Corrosion kinematic parameters have been estimated using potentio-dynamic polarization tests. It has been observed that the corrosion inhibitor does not have any adverse effect on physical properties of cement and cement concrete. The low corrosion current density exhibited by the inhibitor proves their potential in controlling corrosion initiation and propagation.

Active Corrosion Protection by Nanoparticles and Conversion Films of Layered Double Hydroxides

The active corrosion protection of metallic substrates can be achieved by the addition of corrosion inhibitors to protective coatings. However, direct mixing of inhibitors with coating formulations...

Influência do processo de cura das películas híbridas no desempenho de revestimentos obtidos por pintura epoxídica

O pré-tratamento com películas híbridas obtidas pelo processo sol-gel, a partir de precursores alcoóxidos específicos, tem sido uma alternativa, ambientalmente correta, proposta para a proteção contra corrosão de diferentes substratos metálicos, incluindo o aço galvanizado. Nas películas híbridas, os componentes inorgânicos contribuem para o aumento da resistência à corrosão e adesão ao substrato metálico, enquanto os componentes orgânicos aumentam a densidade, flexibilidade e compatibilidade funcional com sistemas orgânicos, como, por exemplo, a pintura. A adição de inibidores de corrosão, ou outros compostos, à película híbrida pode modificar as propriedades de barreira, melhorando a resistência à corrosão. No presente trabalho, o aço galvanizado foi pré-tratado com uma película híbrida obtida a partir de um sol constituído pelos precursores alcoóxidos 3-(trimetoxisililpropil) metacrilato (TMSPMA) e tetraetoxisilano (TEOS), com adição de nitrato de cério, na concentração de 0,01 M. Os filmes híbridos foram submetidos a diferentes mecanismos de cura: secagem ao ar, cura térmica e cura por radiação ultravioleta. Os sistemas obtidos foram caracterizados quanto à aderência, morfologia e comportamento eletroquímico. Além disso, foi avaliado o grau de hidrofobicidade dos sistemas pelo monitoramento do ângulo de contato. Para os ensaios acelerados de corrosão, em câmera de névoa salina, o aço galvanizado pré-tratado com película híbrida foi revestido com pintura epoxídica. Os resultados obtidos mostraram que os sistemas aço galvanizado/película híbrida/pintura epoxídica, com películas híbridas curadas ao ar e por radiação ultravioleta, apresentaram os melhores resultados quanto à resistência à corrosão.

Metal Corrosion Problems and Countermeasures in High Conductivity of Circulating Water

Objective: Through the test of air conditioning cooling water circulation system and the electrical conductivity of iron corrosion velocity, find out the method of corrosion control measures; Methods: Rotating hanging plate method and conductivity meter and other cooling water test air conditioning system in different conductivity of metal iron corrosion rate; Conductivity results: Air-conditioning cooling water circulation system of more than 1900 μs/cm, metal corrosion rate less than 0.05mm/a, shall meet the relevant standards. Conclusion: Through the addition of corrosion inhibitor, scientific emission and control of circulating cooling water pH, conductivity decreased circulating water cooling, can reduce the corrosion of iron, to ensure the safe and stable operation of cooling water pipe and equipment.