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This paper aims to clarify the corrosion inhibition effect of different corrosion inhibitor systems on the corrosion of metal pipe string by potassium persulfate plugging agent, so as to improve the injection capacity of polymer plugging well and reduce the corrosion of steel by oxidant plugging agent.

The effect of different corrosion inhibitors on the corrosion inhibition of N80 carbon steel in 1% potassium persulfate solution was studied by electrochemical experiment and weight loss experiment. The corrosion inhibition mechanism of potassium persulfate inhibitor and the synergistic mechanism among different inhibitors were analyzed.

The results indicated that when the temperature was 50°C, the inhibition effect of 0.2% sodium molybdate with a single inhibitor was the best at pH 8.5, and the inhibition rate was 70.17%. The inhibition efficiency of 0.2% sodium molybdate + 0.3% sodium silicate in the composite inhibition system can reach 94.38%. In the temperature range of 20°C–60°C, with the increase of system temperature, the inhibition effect of corrosion inhibitor will gradually weaken.

The corrosion inhibition system of N80 steel in potassium persulfate oxidant was mainly studied, and it clarified the influence of temperature and pH value on the corrosion inhibition effect, which provided guidance and suggestions for the corrosion inhibition of tubular string in the oilfield.

This paper aims to identify an inhibitor to protect rebar corrosion in concrete.

The authors use the simple method of polarization and calculate the change in open-circuit potential and corrosion current density.

Sodium molybdate is an efficient inhibitor compared with sodium tungstate for rebar corrosion in concrete.

This paper has limitation of 0.0001 M concentration of inhibitors for 400 days of exposure in 3.5 per cent sodium chloride solution.

The research focused on the concentration of both inhibitors in the range from 0.1 to 0.0001 M, which resulted in greater structural protection from corrosion in adverse conditions, such as coastal areas.

Transmission Mossbauer Spectroscopy of corrosion products of mild steel immersed in 3 per cent NaCl and 3 per cent NaCl containing 0.03 M concentrations of different inhibitors viz. sodium nitrite, sodium molybdate, sodium tungstate, sodium meta borate and sodium hexameta phosphate were carried out to understand the corrosion process occurring under these conditions. All corrosion products showed the presence of γ‐FeOOH and superparamagnetic (SPM) α‐FeOOH. However, the corrosion product obtained on mild steel in presence of nitrite showed non‐stoichiometric magnetite (Fe_3−xO₄) along with oxyhydroxides. The corrosion products of steel in presence of phosphate inhibitor showed the presence of ferrous phosphate. The Mossbauer results were supported by FTIR studies. Electrochemical studies showed a high polarisation resistance (Rp) in ease of nitrite inhibitors. Therefore, it can be concluded that an inhibitor which promote the formation Fe_3−xO₄ can provide better protection for steel substrate.

Chromium based conversion coatings have been used widely to delay the formation of white rust on galvanized steel sheets. As chromium is carcinogenic, an alternative chromium‐free conversion coating was developed for use on galvanized steel surfaces to delay the onset of white rusting. This paper seeks to address this issue.

The molybdate coating was produced on galvanized steel surface by dipping in a phosphate solution bath using Na₂MoO₄ as a corrosion inhibitor.

The cyclic polarization tests conducted on molybdates‐treated samples showed a wider potential band in 3.5 per cent NaCl solution, indicating that the coating is passivating in nature. The polarization (R_p) of both treated and untreated samples was evaluated in 3.5 per cent NaCl solution by electrochemical impedance spectroscopy (EIS) technique. It was observed that the polarization resistance (R_p) of molybdate treated galvanized sample is 2.3 times higher compared with the untreated one. The improved corrosion resistance also was evident from the simulated salt spray test results where the treated sample showed a five times improvement over the untreated sample.

The corrosion resistance of inorganic‐based chromium‐free conversion coatings has not been equivalent to that of chromium based conversion coatings. A chromium‐free conversion coating with enhanced corrosion performance by using water reducible polymer will be described in a future paper.

The developed chromium‐free passivation solution has been implemented for galvanized tube passivation. It is one of the best alternative chromium‐free chemicals for the prevention of white rust formation on galvanized materials during transit and storage.

This paper describes a new coating system for the galvanized material which will provide a significant improvement to white rusting resistance for the galvanizing industry.

Molybdenum compounds have a long history of corrosion inhibition in coatings applications. The use of molybdates as cooling water corrosion inhibitors has, however, been limited, although they do offer a number of benefits to the industrial water user.

The inhibition efficiency of the formulation consisting of 1‐hydroxyethane‐1, 1‐diphosphonic acid (HEDP), molybdate and Zn²⁺ in controlling the corrosion of mild steel in neutral aqueous environment containing 60ppm Cl‐ has been evaluated by the weight‐loss method. The formulation consisting of 50ppm HEDP, 300ppm molybdate and 10ppm Zn²⁺ has 97 per cent inhibition efficiency. The nature of the protective film has been analysed by using x‐ray diffraction (XRD), FTIR and fluorescence spectra. The protective film is found to be fluorescent and to consist of Fe²⁺‐HEDP complex, Fe₂(MoO₄)₃ complex and Zn(OH)₂. A suitable mechanism of corrosion inhibition is proposed based on the results obtained from the weight‐loss method, polarisation study, XRD, FTIR, fluorescence and atomic absorption spectra.

The purpose of this paper is to improve binding force between the coating and the steel substrate by using chemical modification on the steel surface; at the same time, it can also increase the corrosion resistance of the coating.

The main components of the conversion film include tannic acid, sodium molybdate and silane coupling agent KH560. After the preparation was completed, the samples were tested and analyzed, including surface morphology, conversion film components, bonding force with organic resins and corrosion resistance. Finally, it drew a conclusion that the conversion film can greatly improve the bonding strength of the steel substrate and epoxy resin.

When the content of tannic acid is 4 g/L meanwhile the content of KH560 is 20 g/L, the conversion film has the strongest binding force with epoxy resin, from 2.15 Mpa of untreated steel to 4.60 Mpa, growth of 140 per cent. At the same time, the resulting conversion film also improves the corrosion resistance of the steel surface by a small margin.

A method of enhancing the bond between an epoxy coating and steel is provided. Verify the mechanism of this method.

Two corrosion inhibitors for closed cooling water systems, nitrite-based and mixture of nitrite and molybdate corrosion inhibitor, are often compared to each other. This study aims to optimize these two inhibitors in terms of concentration and pH for carbon steel protection, with insights into the double layer structure on surface and its impact on corrosion inhibition.

Electrochemical analysis including electrochemical impedance spectroscopy and potentiodynamic test are carried out for quick assessment of corrosion inhibition efficiency and optimization, which is confirmed by immersion test and microscopic analysis. The electronic properties of the surface film are analyzed through Mott–Schottky method which provides new insights into the inhibition mechanism and the role of each component in mixture inhibitor.

Mixture of nitrite and molybdate is shown to present higher inhibition efficiency, owning to the double layer structure. Nitrite alone can form a protective surface film, whereas molybdate leads to an n-type semiconductive film with lower donor density, hence giving rise to a better inhibition effect.

Surface after inhibitor treatment has been carefully characterized to the microscopic scale, implying the effect of micro-structure, chemical composition and electronic properties on the corrosion resistance. Inorganic corrosion inhibitors can be tuned to provide higher efficiency by careful design of surface film structure and composition.

Almost every study on corrosion inhibitor applies such method for quick assessment of corrosion inhibition effect. Mott–Schottky test is one of electrochemical methods that reveals the electronic properties of the surface film. Previous works have studied the surface layer mainly through X-ray photoelectron spectroscopy. This study provides another insight into the surface film treated by nitrite and molybdate through Mott–Schottky analysis, and relates this structure to the corrosion inhibition effect based on multiple analysis including electrochemistry, microscopic characterization, thermodynamics and interface chemistry.

The discovery of the Hall‐Herqult process for the manufacture of aluminium made it possible to obtain the metal in large quantities. Soon it attained the position of a major industrial metal due to its lightness combined with strength, capacity to take up a high polish, excellent conductivity of heat and electricity. Moreover it gives a wide range of extremely valuable alloys with diverse elements such as copper, magnesium, nickel, silicon, zinc, etc.

The purpose of this paper is to investigate the efficient exploitation of bioactive compounds present in red, green and brown seaweeds to develop hygienic products.

To analyse the antioxidant properties and identification of significant bioactive compounds of green, red and brown seaweed treated cotton fabrics, total antioxidant activity, DPPH Free radical scavenging activity and gas chromatography-mass spectrometry analysis were used.

The experimental result specifies that the maximum antioxidant activity of 126.50 µg/ml and inhibition percentage of 76 ± 0.15 percent was achieved in the seaweed treated cotton fabrics. All six seaweed treated fabrics proved slightly lesser water vapour and air permeability compared with the untreated fabric.

The seaweed treated cotton materials are suitable for making wound dressing, surgical wear, face mask, sportswear, healthcare and hygienic applications.