Morphology and Properties of Zn-Al-TiO2 Composite on Mild Steel

The influence of TiO2 composite and dispersed pure Al particle on zinc alloy electrodeposited on mild steel was studied from chloride bath solution.Microstructural and mechanical properties of the alloy were investigated. The structure, surface morphology, and surface topography of the deposited alloys were characterized by scanning electron microscopy (SEM) and atomic force microscope (AFM).In addition, hardness of the coated alloys was measured. It was found that the obtained Zn-Al-TiO2 alloyexhibited more preferred surface morphology and mechanical strength compared tothe substrate. The result shows the existence of interaction between TiO2 compounds and zinc alloy particulate. It also exhibited well bright dominate zinc coating on steel surface

Electrochemical Potential Monitoring of Corrosion and Inhibitors Protection of Mild Steel Embedded in Concrete in NaCl Solution

The corrosion and protection behaviour of mild steel embedded in concrete, and partially immersed in 3.5% sodium chloride solution, was studied in this investigation at ambient temperature by potential monitoring technique. The work was performed with a digital multimeter and a Cu/CuSO4 electrode (CSE) as the reference electrode. Extracts of pawpaw (carica papaya) leaves and sodium nitrite in different concentrations were separately and in combination, used as inhibitors. This paper reports the observed electrochemical response from the electrode potential monitoring of the embedded mild steel during the experiments. The results obtained, showed a reduction in the active corrosion reactions behaviour of the embedded mild steel in concrete admixed with different concentrations of sodium nitrite and the pawpaw leaves extracts thus indicating corrosion inhibition characteristic. The observed inhibition was attributed to the protective film provided on the steel’s surface in the concrete by the complex chemical compounds of the plant leaves’ extracts and the reaction of sodium nitrite with the alkaline environment of the concrete and its constituents. The combination of pawpaw extracts and the NaNO2 solution provided effective corrosion inhibition of the embedded steel by synergism. The 100% concentration of each of the inhibitors and when in combinations, exhibited the most effective corrosion inhibition performanc

PLANTS EXTRACTS CORROSION INHIBITION OF ALUMINIUM ALLOY IN H2SO4

Effects of tobacco (Nicotiana) and Kola tree (Cola acuminata) extracts on the corrosion inhibition of an aluminium alloy 2S (1200) grade specimens immersed in 0.5M sulphuric acid was investigated at ambient temperature by gravimetric and metallographic methods. Extracts of kola plant and tobacco in different concentrations were used as ‘green’ inhibitors. This paper reports the results obtained from the weight loss method, calculated corrosion rates, inhibitor efficiencies and the optical microscopy metallographic observations. Addition of different concentrations of the plants extracts gave clear reduction in weight loss and in the corrosion rate of the test samples. This apparent corrosion inhibition was associated with the protective film provided on the aluminium alloy’s surface by the complex chemical constituents of the plants extracts

Effect of Cola Acuminata and Camellia Sinensis Mixed Extracts on the Corrosion Inhibition of Mild Steel in 0.5M Sulphuric Acid

The corrosion inhibition effect of extracts of kola plant (cola acuminata) and green tea (camellia sinensis) in mixed form on the protection of mild steel specimens immersed in sulphuric acid solution was studied at ambient temperature by gravimetric and potential monitoring methods. The electrode potential monitoring was performed using a digital voltmeter and a saturated calomel electrode (SCE) as the reference electrode. Extracts of kola plant and green tea in different concentrations and combinations were used as ‘green’ inhibitors. There was significant reduction in the weight loss and in the corrosion rate of the test samples, particularly at the added extracts concentration of 100% and also at the concentrations of 50 and 25%. Some very good inhibitor efficiency values were obtained which suggested good corrosion inhibition performance of the added extracts at the concentrations used. Potential measurement values recorded showed a reduction in active corrosion reactions for all the combinations of the extracts. This behavior was attributed to the protective film provided on the steel’s surface by the complex chemical constituents of the plants extracts. The best corrosion inhibition performance for mild steel was obtained using the combined extracts of kola leaf and green tea at100% concentration. The combination of kola leaf, kola nut and green tea at the same concentration was also effective in corrosion inhibition performanc

Inhibition Effect of Kola Tree and Tobacco Extracts on the Corrosion of Austenitic Stainless Steel in Acid Chloride Environment

Corrosion and inhibitor protection of austenitic stainless steel (Type 304) specimens immersed in acid chloride solution was investigated at ambient temperature by weight loss method from which the corrosion rates were calculated and inhibition efficiency determined. Extracts of kola plant; the nut, bark and leaf and tobacco leaf in different concentrations were used as ‘green’ inhibitors. This paper reports the results obtained from the various tests performed in the acid chloride environment on the stainless steel during the experiments. The addition of different concentrations of the plants extracts gave some reduction in the active corrosion reactions behavior of the steel specimen in the strong acid chloride. There was a reduction in the weight loss and in the corrosion rate of the test samples, though not very significant. The stainless steel was self-passivated; the passive film was, however, significantly destroyed by the strong reacting species of the test solution. The reduction in weight loss was attributed to the protective film provided on the steel’s surface by the complex chemical constituents of the plants extracts. Effective protection of the austenitic stainless steel was minimally achieved in nearly all the extracts for the greater part of the experimental perio

Inhibition effect of potassium dichromate on the corrosion protection of mild steel reinforcement in concrete

The inhibition of potassium dichromate on the corrosion protection of mild steel embedded in concrete and partially immersed in sulphuric acid and sodium chloride environments was evaluated at ambient temperatures. The experiments were performed using electrochemical potential monitoring method. Varying quantities of the inhibitor was used. In the NaCl test medium, the effectiveness of the inhibitor improved as higher concentration was used. The best inhibition was achieved in the reinforced concrete sample admixed with 9 g potassium dichromate. Steel-reinforced concrete sample admixed with 3 and 9 g potassium dichromate inhibitor had the highest improvement in compressive strength. The potassium dichromate inhibitor was most effective amongst other inhibitor concentrations used when 7.5 g was admixed with the sample in the H2SO4 medium. The sulphuric acid medium had a deleterious effect on the strength of concrete test specimens

Inhibition Effect of Extracts of Carica Papaya and Camellia Sinensis Leaves on the Corrosion of Duplex (α β) Brass in 1M Nitric Acid

The effect of C. Papaya (pawpaw) leaves and C. Sinensis (tea) extracts as an organic „green‟ inhibitor on the corrosion of α β (duplex) brass (65-35% Cu-Zn alloy) in 1MHNO3 (nitric acid) was studied at ambient temperature. Weight loss/corrosion rate and potential measurement techniques were used for the experimental work. The tea extract was obtained from the green tea leaves. The results obtained showed effective corrosion inhibition of the extracts on the brass test specimens in the 1M nitric acid used. The different combined extracts concentrations also gave good corrosion inhibition performance. They also exhibited effective corrosion reactions synergism. The test specimen (duplex brass) gave some appreciable corrosion resistance in the test environmen

Corrosion Inhibition of Thiourea and Thiadiazole Derivatives : A Review

The continuous search for better corrosion inhibitors, due to vast differences in the media encountered in industry remains a focal point in corrosion control. The use of organic compounds to inhibit corrosion has assumed great significance due to their application in preventing corrosion under various corrosive environments. These compounds have great potential to inhibit aqueous corrosion due to film formation by adsorption on the metal surface. This paper reviews the inhibitive effect of thiourea and thiadiazole derivatives. This group of organosulphur and heterocyclic compounds and derivatives has important theoretical and practical applications, but their inhibition mechanism is not fully understood, despite extensive study. The effect of these compounds on the corrosion of metallic alloys was evaluated through assessment of various journals and experimental techniques. The corrosion rate was found to be a function of different variables. Due attention was paid to the systematic study of inhibitor action of derivatives with much emphasis on the functional groups of the molecular structure. From the comprehensive discourse presented, it is concluded that the derivatives fulfill the basic requirements for consideration as an efficient corrosion inhibito