Oil well acidizing, although a stimulation process, induces the corrosion of metallic equipment a... more Oil well acidizing, although a stimulation process, induces the corrosion of metallic equipment and well tubing. There is, at present, a high demand for effective and less toxic high-temperature corrosion inhibitors for the acidizing process due to the failing of the existing inhibitors at high temperatures occasioned by increases in the well depths. In this study, aspartame (ASP), a commercially available natural compound, is examined as a corrosion inhibitor for T95 carbon steel in 15 wt.% HCl solution at 60, 70, 80, and 90 °C using the weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), and optical profilometry (OP) techniques. It was found that ASP possesses a corrosion inhibiting effect at the studied conditions. Inhibition efficiency increased with increases in temperature. With 2000 ppm ASP, inhibition efficiency of 86% was achieved from the weight loss method ...
IOP Conference Series: Materials Science and Engineering
Zn electrodeposition on low carbon steel (LCS) within an acid bath composed of ZnCl2, H3BO3 and K... more Zn electrodeposition on low carbon steel (LCS) within an acid bath composed of ZnCl2, H3BO3 and KCl solution at predetermined quantities of ginger, celery and pomegranate extracts with respect to plating time was evaluated. Results obtained showed the plant extracts significantly influenced Zn electrodeposition on LCS with respect to concentration. Ginger extracts induced the highest Zn electrodeposited with values between 0.0867 g and 0.1219 g. Comparison of corrosion resistance between the non-plated and Zn electrodeposited LCS (with and without extract additives) were determined with potentiodynamic polarization method. Results showed ginger, pomegranate and celery extracts enhanced the corrosion resistance of Zn electrodeposited LCS with highest corrosion rate values of 2.48 mm/y, 2.78 mm/y and 1.95 mm/y compared to 7.96 mm/y for non-plated LCS and 6.58 mm/y for Zn electrodeposited LCS without plant extracts.
IOP Conference Series: Materials Science and Engineering
Gravimetric and statistical analysis was used to assess the protection performance of aminobenzen... more Gravimetric and statistical analysis was used to assess the protection performance of aminobenzene compound on 1070 aluminum alloy in 1 M HCl solution in volumetric concentrations of 2.5%, 5%, 7.5%, 10%, 12.5% and 15%. Data output shows aminobenzene performed poorly at lower concentrations (2.5% to 10% aminobenzene concentrations) with highest value of 61.3% at 10% concentration and 480 h of exposure time. However, at higher concentrations the corrosion and oxidation of the aluminium surface was effectively suppressed with peak value of 81.7% at 480 h of exposure. Aminobenzene inhibition performance was determined to be highly concentration dependent with limited variation with respect to observation time. Standard deviation data showed significant variation of protection performance data at lower aminobenzene concentrations due to variation of the protection performance data with respect to observation time and thermodynamic instability of the inhibition mechanism. At 12.5% and 15%...
1,4-Diaminobenzene was studied for its electrochemical influence on the corrosion behaviour of mi... more 1,4-Diaminobenzene was studied for its electrochemical influence on the corrosion behaviour of mild steel in dilute H 2 SO 4 and HCl acid at ambient temperature with the application of weight loss technique, open circuit potential measurement and potentiodynamic polarization test. Results show the inhibition efficiency of the organic derivative varied with concentration with maximum inhibition efficiency of 70% and 78.2% at 0.093M inhibitor concentration in H 2 SO 4 acid and a maximum inhibition efficiency of 81.1% and 94.3% at 0.069M inhibitor concentration in HCl acid from weight loss and polarization tests proving to be more effective in HCl. Potential measurement results varied, with passivity potentials being maintained at specific concentrations. SEM observations showed a significant morphological appearance with contrasts micrographs from uninhibited samples. X-ray diffractometry confirmed the absence of reaction products and phase complexes associated with corrosion. Statistical analysis showed relevance and statistical significance of concentration and exposure time on the inhibition performance of 1, 4diaminobenzene.
The inhibition and adsorption effects of Lavandula and Ricinus communis oils on mild steel corros... more The inhibition and adsorption effects of Lavandula and Ricinus communis oils on mild steel corrosion in 0.5 M H2SO4 were studied at ambient temperature of 25°C. Gravimetric and potentiodynamic polarization measurement methods were used for the experiments. A Digi-Ivy potentiostat, interfaced with a computer for data acquisition and analysis was used for the potentiodynamic polarization experiments. The inhibition performance decreased with increasing concentration of the mixed inhibitors in the H2SO4 test medium. The low inhibitor concentrations of 2 ml, 4 ml, 6 ml/250 ml H2SO4 were relatively similar and had weight loss values of 0.152 g, 0.254 g, 0.21 g, respectively. At 336 h of the experiment, the concentration of 12 ml/250ml H2SO4 hаԁ the highest recorded weight loss value of 0.821g. The corresponding corrosion rate values for these concentrations were respectively 0.84 mm/year, 1.40 mm/ year and 1.16 mm/year. The corrosion inhibition efficiency values for the 12 ml/250 ml H2SO...
Electrochemical noise measurement is one of the novel techniques currently being used in corrosio... more Electrochemical noise measurement is one of the novel techniques currently being used in corrosion monitoring. Two major methods of analysis in use are the Fast Fourier Transform (FFT) and the Maximum Entropy Method (MEM). This paper reviews the techniques fundamental background – types of noise, physical data; description, classification and characteristics; mathematical background of random data and spectral analysis. Recent progress made in its application to corrosion monitoring and other electrochemical reaction phenomena are also examined.
International Journal of Electrochemical Science, 2014
The plating quality effect of manihot esculenta c. (cassava) leaf extract as addition agent on th... more The plating quality effect of manihot esculenta c. (cassava) leaf extract as addition agent on the electroplating of zinc on mild steel in acid chloride solution was investigated in the laboratory. The experiments were performed using different extract additive concentrations, different plating time and fixed pH conditions. A DC – supply at defined operating parameters was used to perform the electroplating of zinc on mild steel. The surface of the plated steel was examined using a scanning electron microscope (SEM) equipped with Energy Dispersive Spectroscopy (EDS). This was used to examine the surface of the plated steel for surface morphology and for surface elemental composition analysis. Distinct variable surface characteristics were obtained depending upon the concentration of the additive and the plating time. The corrosion resistance of the plated surface was determined by gravimetric, potential measurement and corrosion current methods. The coating efficiencies were also de...
The effect of Camellia Sinensis (green tea) extract as a green inhibitor on the corrosion of alum... more The effect of Camellia Sinensis (green tea) extract as a green inhibitor on the corrosion of aluminium alloy in 0.8M sulphuric acid was studied at room temperature. Weight loss/corrosion rate and potential measurement techniques were used for the experimental work. The results were further analysed using the two-factor ANOVA test. Potential measurement was performed using a digital voltmeter and a saturated calomel reference electrode. The tea extract was obtained from the green tea leaves. The results obtained showed effective corrosion inhibition of the extract on the aluminium alloy test specimens in the different concentrations of sulphuric acid used. The extracts gave appreciable corrosion inhibition performance of aluminium at 20 and 40% concentrations with the weight loss of 236mg (0.236g) and 265 mg (0.265g) respectively. ANOVA test confirmed the results at 95% confidence, and further showed that concentration of green tea extract had greater effect on potential and weight l...
An investigation of the plating quality effect of Allium cepa extract as addition agent on the el... more An investigation of the plating quality effect of Allium cepa extract as addition agent on the electroplating of zinc on mild steel in acid chloride solution was done in the laboratory. Different extract concentrations, different plating time and fixed pH conditions were used to perform the experiments. A DC – supplier at defined operating parameters was used to perform the electroplating of zinc on mild steel. Scanning electron microscope (SEM) equipped with Energy Dispersive Spectroscopy (EDS) was used to examine the surface of the plated steel for surface morphology and surface elemental composition analysis. Variable surface characteristics were obtained depending upon the concentration of the additive and the plating time. Potential measurement, corrosion current and gravimetric methods were used to monitor and determine the corrosion resistance of the plated surface. The coating efficiencies were also determined. Entirely new and different metal substrate surface morphology we...
The corrosion resistance and/or susceptibility of Type 316 austenitic stainless steel was separat... more The corrosion resistance and/or susceptibility of Type 316 austenitic stainless steel was separately performed at ambient temperature in different concentrations (the intermediate and the concentrated) of sulphuric acid, H2SO4, and phosphoric acid, H3PO4. Similar tests were also performed by the addition of 2% (20g/l) sodium chloride, NaCl, to each of the specified acid concentrations to form their acid chlorides. Potentiostatic polarization method was used for the corrosion investigation. The electrochemical corrosion reactions exhibited both the passive and active corrosion reactions characteristics. The acids at the intermediate concentrations show more obvious active corrosion reactions; while in the concentrated form they were relatively passive – the passivity that was associated with the oxidizing nature of the concentrated acids. The addition of 2% NaCl to each of the test medium concentration gave increased active corrosion reactions that could be due to the test electrodes...
The performance effects of thiourea and dextrin as addition agents on the electroplating of zinc ... more The performance effects of thiourea and dextrin as addition agents on the electroplating of zinc on mild steel in acid chloride solution were experimentally investigated. The experiments were performed under different additive concentrations, different plating time and fixed pH conditions. The zinc electroplating on mild steel was performed using a DC – supply at defined operating parameters. The surface of the plated steel was examined using scanning electron microscopy (SEM) for surface morphology; and Energy Dispersive Spectroscopy (EDS) for surface elemental composition analysis. Different surface characteristics were obtained depending upon the concentration of the additive and the plating time. The corrosion resistance of the plated surface was determined by gravimetric method. The quality of the electro-deposition of zinc was good as indicated by the microstructural feature of the plated surface. The electrodeposition process was sensitive to changes in additive concentration...
This study reports the effect of Camellia Sinensis (green tea) extract as a green inhibitor on th... more This study reports the effect of Camellia Sinensis (green tea) extract as a green inhibitor on the corrosion of aluminium alloy in 0.5M hydrochloric acid. Weight loss/corrosion rate and potential measurement techniques were used for the experimental work. The results were further analysed using the two-factor ANOVA test. Potential measurement was performed using a digital voltmeter and a saturated calomel reference electrode. The tea extract was obtained from the green tea leaves. The results obtained showed effective corrosion inhibition of the extract on the aluminium alloy test specimens in the different concentrations of hydrochloric acid used. The extracts gave appreciable corrosion inhibition performance of aluminium at 100 and 80% concentrations with the weight loss of 652mg (0.652g) and 674 mg (0.674g) respectively. ANOVA test confirmed the results at 95% confidence, and further showed that concentration of green tea extract had greater effect on potential measurements where...
The corrosion inhibition performance of Neem leaf (Azadirachita indica) extract on the corrosion ... more The corrosion inhibition performance of Neem leaf (Azadirachita indica) extract on the corrosion of mild steel test specimen immersed in 0.5 M HCl and H2SO4 acids respectively at the ambient temperature of 30°C and elevated temperature of 80°C was investigated. The experimental work was performed by the use of weight loss method and the potential measurement technique. From the weight loss values, corrosion rates were determined by calculation. In the results obtained, the leaf extract, in sulphuric acid medium, gave its best corrosion inhibition performance at 0.50 g/l extract concentration at 30°C. A more appreciable corrosion inhibition performance was achieved in the dilute hydrochloric acid at 0.25 g/l extract concentration and also at 30°C.
Carburization tests and analysis were performed on some samples of radiant tube alloys of ethylen... more Carburization tests and analysis were performed on some samples of radiant tube alloys of ethylene furnaces at three petrochemical plants. These tubes had undergone carburization in service with some losing their structural integrity. This study evaluates and compares the carburization resistance performances of some of these tubes in service and identifies the cause of their degradation. The polished surfaces of the test samples were visually observed. The depth of carburization zones for each test sample was measured. Scanning electron microscopy and energy dispersive x-ray spectroscopy were used to examine the carburization zones and the rest part of the specimens and to characterize the microstructure and elemental composition of the tubes’ material. Optical microscope (Image analyzer) was used to examine the etched surface of each of the test samples. Microhardness testing was performed to determine their mechanical strength. Visual inspection revealed the sagging in some of th...
In the last two decades sachet water production and consumption has become an integral part of ou... more In the last two decades sachet water production and consumption has become an integral part of our consumption culture in Nigerian cities and towns. Its emergence and growth has some significant environmental and socio-economic implications. The aim of this study was to assess social impacts of sachet water production in Nigeria. This paper reports a Social Lifecycle Assessment Methodology developed to evaluate social effects of sachet water production on workers and on the local community where its production is taking place. The methodology is demonstrated with a case study on a Sachet Water brand production by a company in Sango-Ota. The social performance score of the sachet water production facility is 35.7% on workers and 50% on local community. The overall social performance is 42.3%. Results of the analysis revealed social benefits and community engagement as significant issues. The facility therefore needs to make significant improvement on a number of social aspects of its...
Gravimetric and statistical analysis was used to assess the protection performance of aminobenzen... more Gravimetric and statistical analysis was used to assess the protection performance of aminobenzene compound on 1070 aluminum alloy in 1 M HCl solution in volumetric concentrations of 2.5%, 5%, 7.5%, 10%, 12.5% and 15%. Data output shows aminobenzene performed poorly at lower concentrations (2.5% to 10% aminobenzene concentrations) with highest value of 61.3% at 10% concentration and 480 h of exposure time. However, at higher concentrations the corrosion and oxidation of the aluminium surface was effectively suppressed with peak value of 81.7% at 480 h of exposure. Aminobenzene inhibition performance was determined to be highly concentration dependent with limited variation with respect to observation time. Standard deviation data showed significant variation of protection performance data at lower aminobenzene concentrations due to variation of the protection performance data with respect to observation time and thermodynamic instability of the inhibition mechanism. At 12.5% and 15%...
The electrochemical corrosion behaviour of n, n’-diphenylthiourea on the surface properties mild ... more The electrochemical corrosion behaviour of n, n’-diphenylthiourea on the surface properties mild steel in attenuated sulphuric and hydrochloric acids (3M concentration) contaminated with 3.5% recrystalized sodium chloride at ambient temperatures was examined through weight loss analysis, open circuit potential monitoring and potentiodynamic polarization. The surface morphology of the samples was analyzed with scanning electron microscopy and x-ray diffractometry. Statistical analysis of the results was done with aid of ANOVA software to assess their statistical relevance. Results show the thiourea derivative performed more excellently in sulphuric than hydrochloric acid based on inhibition efficiency values. Observations from SEM/XRD image and data further confirm the results of experimental data. Statistical derivations reveal the overwhelming influence of exposure time on inhibition performance compared to concentration of the organic compound.
In this paper, measurements of corrosion test data from steel reinforced concrete samples immerse... more In this paper, measurements of corrosion test data from steel reinforced concrete samples immersed in 3.5% NaCl, for simulating saline/marine environment, were analysed for investigating corrosion mechanism by Morinda lucida leaf extract admixtures on the steel rebar. Corrosion potential as per ASTM C876-95 R99, corrosion current by zero resistance ammeter and corrosion rate from linear polarization resistance instrument were subjected to the Weibull probability distribution as per Kolmogorov-Smirnov goodness of fit criteria. From this, electrochemical noise resistance was modelled through the ratio of Weibull standard deviation of corrosion potential to that of Weibull standard deviation of corrosion current after which the modelled noise resistance and the plant extract concentration were correlated with the corrosion rate. Results from these analyses of electrochemical test data showed that excellent correlation, of R = 98.07%, Nash-Sutcliffe Efficiency = 96.18% and ANOVA p-value...
Analysis of the protection performance of kolanut leaves (KL), kolanut fruits (KF), tobacco leave... more Analysis of the protection performance of kolanut leaves (KL), kolanut fruits (KF), tobacco leaves (TL) and bitter leaves (BL) extracts at 30%, 60% and 80% concentration on plain carbon steel in 0.5 M H2SO4 solution was done by gravimetric measurement and statistical evaluation. Data output showed KF and TL extracts performed effectively at all concentrations studied with protection performance output generally above 80%. KL and BL extracts performed poorly at the lowest concentration while at higher concentrations optimal protection performance outputs are 74.41% and 83.53%. The protection performance outputs of KL, KF and TL extracts varied significantly with observation time due to thermodynamic instability and unstable inhibition behavior. BF extract exhibited stable inhibition behavior due to general stability of its protection performance outputs with respect to observation time. BF and KL exhibited the highest and lowest standard deviation due to the degree of variation of th...
IOP Conference Series: Materials Science and Engineering
The corrosion resistance of as-received and heat treated C26000 brass (annealed and quenched) was... more The corrosion resistance of as-received and heat treated C26000 brass (annealed and quenched) was evaluated by gravimetric analysis in 0.5 M, 1 M, 1.5 M, 2 M, 2.5 M, 3 M and 3.5 M HNO3 solution. Generally, corrosion rate of C26000 increased with increase in HNO3 concentration and varies significantly with respect to observation time. Results showed that heat treatment has no influence on the corrosion resistance of the brass heat treated brass compared to the as-received sample. Application of garlic extracts in HNO3 solution at 0.5 M significantly decreased the corrosion rate of C26000 60% concentration with inhibition value of 79.46%. The garlic extract exhibited significant concentration dependent behaviour and its inhibition performance varies with observation time. Statistical evaluation showed the standard deviation values of as-received and heat treated C26000 varied with respect to mean inhibition data. However, variation increased with HNO3 concentration due to thermodynami...
Oil well acidizing, although a stimulation process, induces the corrosion of metallic equipment a... more Oil well acidizing, although a stimulation process, induces the corrosion of metallic equipment and well tubing. There is, at present, a high demand for effective and less toxic high-temperature corrosion inhibitors for the acidizing process due to the failing of the existing inhibitors at high temperatures occasioned by increases in the well depths. In this study, aspartame (ASP), a commercially available natural compound, is examined as a corrosion inhibitor for T95 carbon steel in 15 wt.% HCl solution at 60, 70, 80, and 90 °C using the weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscope (SEM), energy dispersive spectroscopy (EDX), and optical profilometry (OP) techniques. It was found that ASP possesses a corrosion inhibiting effect at the studied conditions. Inhibition efficiency increased with increases in temperature. With 2000 ppm ASP, inhibition efficiency of 86% was achieved from the weight loss method ...
IOP Conference Series: Materials Science and Engineering
Zn electrodeposition on low carbon steel (LCS) within an acid bath composed of ZnCl2, H3BO3 and K... more Zn electrodeposition on low carbon steel (LCS) within an acid bath composed of ZnCl2, H3BO3 and KCl solution at predetermined quantities of ginger, celery and pomegranate extracts with respect to plating time was evaluated. Results obtained showed the plant extracts significantly influenced Zn electrodeposition on LCS with respect to concentration. Ginger extracts induced the highest Zn electrodeposited with values between 0.0867 g and 0.1219 g. Comparison of corrosion resistance between the non-plated and Zn electrodeposited LCS (with and without extract additives) were determined with potentiodynamic polarization method. Results showed ginger, pomegranate and celery extracts enhanced the corrosion resistance of Zn electrodeposited LCS with highest corrosion rate values of 2.48 mm/y, 2.78 mm/y and 1.95 mm/y compared to 7.96 mm/y for non-plated LCS and 6.58 mm/y for Zn electrodeposited LCS without plant extracts.
IOP Conference Series: Materials Science and Engineering
Gravimetric and statistical analysis was used to assess the protection performance of aminobenzen... more Gravimetric and statistical analysis was used to assess the protection performance of aminobenzene compound on 1070 aluminum alloy in 1 M HCl solution in volumetric concentrations of 2.5%, 5%, 7.5%, 10%, 12.5% and 15%. Data output shows aminobenzene performed poorly at lower concentrations (2.5% to 10% aminobenzene concentrations) with highest value of 61.3% at 10% concentration and 480 h of exposure time. However, at higher concentrations the corrosion and oxidation of the aluminium surface was effectively suppressed with peak value of 81.7% at 480 h of exposure. Aminobenzene inhibition performance was determined to be highly concentration dependent with limited variation with respect to observation time. Standard deviation data showed significant variation of protection performance data at lower aminobenzene concentrations due to variation of the protection performance data with respect to observation time and thermodynamic instability of the inhibition mechanism. At 12.5% and 15%...
1,4-Diaminobenzene was studied for its electrochemical influence on the corrosion behaviour of mi... more 1,4-Diaminobenzene was studied for its electrochemical influence on the corrosion behaviour of mild steel in dilute H 2 SO 4 and HCl acid at ambient temperature with the application of weight loss technique, open circuit potential measurement and potentiodynamic polarization test. Results show the inhibition efficiency of the organic derivative varied with concentration with maximum inhibition efficiency of 70% and 78.2% at 0.093M inhibitor concentration in H 2 SO 4 acid and a maximum inhibition efficiency of 81.1% and 94.3% at 0.069M inhibitor concentration in HCl acid from weight loss and polarization tests proving to be more effective in HCl. Potential measurement results varied, with passivity potentials being maintained at specific concentrations. SEM observations showed a significant morphological appearance with contrasts micrographs from uninhibited samples. X-ray diffractometry confirmed the absence of reaction products and phase complexes associated with corrosion. Statistical analysis showed relevance and statistical significance of concentration and exposure time on the inhibition performance of 1, 4diaminobenzene.
The inhibition and adsorption effects of Lavandula and Ricinus communis oils on mild steel corros... more The inhibition and adsorption effects of Lavandula and Ricinus communis oils on mild steel corrosion in 0.5 M H2SO4 were studied at ambient temperature of 25°C. Gravimetric and potentiodynamic polarization measurement methods were used for the experiments. A Digi-Ivy potentiostat, interfaced with a computer for data acquisition and analysis was used for the potentiodynamic polarization experiments. The inhibition performance decreased with increasing concentration of the mixed inhibitors in the H2SO4 test medium. The low inhibitor concentrations of 2 ml, 4 ml, 6 ml/250 ml H2SO4 were relatively similar and had weight loss values of 0.152 g, 0.254 g, 0.21 g, respectively. At 336 h of the experiment, the concentration of 12 ml/250ml H2SO4 hаԁ the highest recorded weight loss value of 0.821g. The corresponding corrosion rate values for these concentrations were respectively 0.84 mm/year, 1.40 mm/ year and 1.16 mm/year. The corrosion inhibition efficiency values for the 12 ml/250 ml H2SO...
Electrochemical noise measurement is one of the novel techniques currently being used in corrosio... more Electrochemical noise measurement is one of the novel techniques currently being used in corrosion monitoring. Two major methods of analysis in use are the Fast Fourier Transform (FFT) and the Maximum Entropy Method (MEM). This paper reviews the techniques fundamental background – types of noise, physical data; description, classification and characteristics; mathematical background of random data and spectral analysis. Recent progress made in its application to corrosion monitoring and other electrochemical reaction phenomena are also examined.
International Journal of Electrochemical Science, 2014
The plating quality effect of manihot esculenta c. (cassava) leaf extract as addition agent on th... more The plating quality effect of manihot esculenta c. (cassava) leaf extract as addition agent on the electroplating of zinc on mild steel in acid chloride solution was investigated in the laboratory. The experiments were performed using different extract additive concentrations, different plating time and fixed pH conditions. A DC – supply at defined operating parameters was used to perform the electroplating of zinc on mild steel. The surface of the plated steel was examined using a scanning electron microscope (SEM) equipped with Energy Dispersive Spectroscopy (EDS). This was used to examine the surface of the plated steel for surface morphology and for surface elemental composition analysis. Distinct variable surface characteristics were obtained depending upon the concentration of the additive and the plating time. The corrosion resistance of the plated surface was determined by gravimetric, potential measurement and corrosion current methods. The coating efficiencies were also de...
The effect of Camellia Sinensis (green tea) extract as a green inhibitor on the corrosion of alum... more The effect of Camellia Sinensis (green tea) extract as a green inhibitor on the corrosion of aluminium alloy in 0.8M sulphuric acid was studied at room temperature. Weight loss/corrosion rate and potential measurement techniques were used for the experimental work. The results were further analysed using the two-factor ANOVA test. Potential measurement was performed using a digital voltmeter and a saturated calomel reference electrode. The tea extract was obtained from the green tea leaves. The results obtained showed effective corrosion inhibition of the extract on the aluminium alloy test specimens in the different concentrations of sulphuric acid used. The extracts gave appreciable corrosion inhibition performance of aluminium at 20 and 40% concentrations with the weight loss of 236mg (0.236g) and 265 mg (0.265g) respectively. ANOVA test confirmed the results at 95% confidence, and further showed that concentration of green tea extract had greater effect on potential and weight l...
An investigation of the plating quality effect of Allium cepa extract as addition agent on the el... more An investigation of the plating quality effect of Allium cepa extract as addition agent on the electroplating of zinc on mild steel in acid chloride solution was done in the laboratory. Different extract concentrations, different plating time and fixed pH conditions were used to perform the experiments. A DC – supplier at defined operating parameters was used to perform the electroplating of zinc on mild steel. Scanning electron microscope (SEM) equipped with Energy Dispersive Spectroscopy (EDS) was used to examine the surface of the plated steel for surface morphology and surface elemental composition analysis. Variable surface characteristics were obtained depending upon the concentration of the additive and the plating time. Potential measurement, corrosion current and gravimetric methods were used to monitor and determine the corrosion resistance of the plated surface. The coating efficiencies were also determined. Entirely new and different metal substrate surface morphology we...
The corrosion resistance and/or susceptibility of Type 316 austenitic stainless steel was separat... more The corrosion resistance and/or susceptibility of Type 316 austenitic stainless steel was separately performed at ambient temperature in different concentrations (the intermediate and the concentrated) of sulphuric acid, H2SO4, and phosphoric acid, H3PO4. Similar tests were also performed by the addition of 2% (20g/l) sodium chloride, NaCl, to each of the specified acid concentrations to form their acid chlorides. Potentiostatic polarization method was used for the corrosion investigation. The electrochemical corrosion reactions exhibited both the passive and active corrosion reactions characteristics. The acids at the intermediate concentrations show more obvious active corrosion reactions; while in the concentrated form they were relatively passive – the passivity that was associated with the oxidizing nature of the concentrated acids. The addition of 2% NaCl to each of the test medium concentration gave increased active corrosion reactions that could be due to the test electrodes...
The performance effects of thiourea and dextrin as addition agents on the electroplating of zinc ... more The performance effects of thiourea and dextrin as addition agents on the electroplating of zinc on mild steel in acid chloride solution were experimentally investigated. The experiments were performed under different additive concentrations, different plating time and fixed pH conditions. The zinc electroplating on mild steel was performed using a DC – supply at defined operating parameters. The surface of the plated steel was examined using scanning electron microscopy (SEM) for surface morphology; and Energy Dispersive Spectroscopy (EDS) for surface elemental composition analysis. Different surface characteristics were obtained depending upon the concentration of the additive and the plating time. The corrosion resistance of the plated surface was determined by gravimetric method. The quality of the electro-deposition of zinc was good as indicated by the microstructural feature of the plated surface. The electrodeposition process was sensitive to changes in additive concentration...
This study reports the effect of Camellia Sinensis (green tea) extract as a green inhibitor on th... more This study reports the effect of Camellia Sinensis (green tea) extract as a green inhibitor on the corrosion of aluminium alloy in 0.5M hydrochloric acid. Weight loss/corrosion rate and potential measurement techniques were used for the experimental work. The results were further analysed using the two-factor ANOVA test. Potential measurement was performed using a digital voltmeter and a saturated calomel reference electrode. The tea extract was obtained from the green tea leaves. The results obtained showed effective corrosion inhibition of the extract on the aluminium alloy test specimens in the different concentrations of hydrochloric acid used. The extracts gave appreciable corrosion inhibition performance of aluminium at 100 and 80% concentrations with the weight loss of 652mg (0.652g) and 674 mg (0.674g) respectively. ANOVA test confirmed the results at 95% confidence, and further showed that concentration of green tea extract had greater effect on potential measurements where...
The corrosion inhibition performance of Neem leaf (Azadirachita indica) extract on the corrosion ... more The corrosion inhibition performance of Neem leaf (Azadirachita indica) extract on the corrosion of mild steel test specimen immersed in 0.5 M HCl and H2SO4 acids respectively at the ambient temperature of 30°C and elevated temperature of 80°C was investigated. The experimental work was performed by the use of weight loss method and the potential measurement technique. From the weight loss values, corrosion rates were determined by calculation. In the results obtained, the leaf extract, in sulphuric acid medium, gave its best corrosion inhibition performance at 0.50 g/l extract concentration at 30°C. A more appreciable corrosion inhibition performance was achieved in the dilute hydrochloric acid at 0.25 g/l extract concentration and also at 30°C.
Carburization tests and analysis were performed on some samples of radiant tube alloys of ethylen... more Carburization tests and analysis were performed on some samples of radiant tube alloys of ethylene furnaces at three petrochemical plants. These tubes had undergone carburization in service with some losing their structural integrity. This study evaluates and compares the carburization resistance performances of some of these tubes in service and identifies the cause of their degradation. The polished surfaces of the test samples were visually observed. The depth of carburization zones for each test sample was measured. Scanning electron microscopy and energy dispersive x-ray spectroscopy were used to examine the carburization zones and the rest part of the specimens and to characterize the microstructure and elemental composition of the tubes’ material. Optical microscope (Image analyzer) was used to examine the etched surface of each of the test samples. Microhardness testing was performed to determine their mechanical strength. Visual inspection revealed the sagging in some of th...
In the last two decades sachet water production and consumption has become an integral part of ou... more In the last two decades sachet water production and consumption has become an integral part of our consumption culture in Nigerian cities and towns. Its emergence and growth has some significant environmental and socio-economic implications. The aim of this study was to assess social impacts of sachet water production in Nigeria. This paper reports a Social Lifecycle Assessment Methodology developed to evaluate social effects of sachet water production on workers and on the local community where its production is taking place. The methodology is demonstrated with a case study on a Sachet Water brand production by a company in Sango-Ota. The social performance score of the sachet water production facility is 35.7% on workers and 50% on local community. The overall social performance is 42.3%. Results of the analysis revealed social benefits and community engagement as significant issues. The facility therefore needs to make significant improvement on a number of social aspects of its...
Gravimetric and statistical analysis was used to assess the protection performance of aminobenzen... more Gravimetric and statistical analysis was used to assess the protection performance of aminobenzene compound on 1070 aluminum alloy in 1 M HCl solution in volumetric concentrations of 2.5%, 5%, 7.5%, 10%, 12.5% and 15%. Data output shows aminobenzene performed poorly at lower concentrations (2.5% to 10% aminobenzene concentrations) with highest value of 61.3% at 10% concentration and 480 h of exposure time. However, at higher concentrations the corrosion and oxidation of the aluminium surface was effectively suppressed with peak value of 81.7% at 480 h of exposure. Aminobenzene inhibition performance was determined to be highly concentration dependent with limited variation with respect to observation time. Standard deviation data showed significant variation of protection performance data at lower aminobenzene concentrations due to variation of the protection performance data with respect to observation time and thermodynamic instability of the inhibition mechanism. At 12.5% and 15%...
The electrochemical corrosion behaviour of n, n’-diphenylthiourea on the surface properties mild ... more The electrochemical corrosion behaviour of n, n’-diphenylthiourea on the surface properties mild steel in attenuated sulphuric and hydrochloric acids (3M concentration) contaminated with 3.5% recrystalized sodium chloride at ambient temperatures was examined through weight loss analysis, open circuit potential monitoring and potentiodynamic polarization. The surface morphology of the samples was analyzed with scanning electron microscopy and x-ray diffractometry. Statistical analysis of the results was done with aid of ANOVA software to assess their statistical relevance. Results show the thiourea derivative performed more excellently in sulphuric than hydrochloric acid based on inhibition efficiency values. Observations from SEM/XRD image and data further confirm the results of experimental data. Statistical derivations reveal the overwhelming influence of exposure time on inhibition performance compared to concentration of the organic compound.
In this paper, measurements of corrosion test data from steel reinforced concrete samples immerse... more In this paper, measurements of corrosion test data from steel reinforced concrete samples immersed in 3.5% NaCl, for simulating saline/marine environment, were analysed for investigating corrosion mechanism by Morinda lucida leaf extract admixtures on the steel rebar. Corrosion potential as per ASTM C876-95 R99, corrosion current by zero resistance ammeter and corrosion rate from linear polarization resistance instrument were subjected to the Weibull probability distribution as per Kolmogorov-Smirnov goodness of fit criteria. From this, electrochemical noise resistance was modelled through the ratio of Weibull standard deviation of corrosion potential to that of Weibull standard deviation of corrosion current after which the modelled noise resistance and the plant extract concentration were correlated with the corrosion rate. Results from these analyses of electrochemical test data showed that excellent correlation, of R = 98.07%, Nash-Sutcliffe Efficiency = 96.18% and ANOVA p-value...
Analysis of the protection performance of kolanut leaves (KL), kolanut fruits (KF), tobacco leave... more Analysis of the protection performance of kolanut leaves (KL), kolanut fruits (KF), tobacco leaves (TL) and bitter leaves (BL) extracts at 30%, 60% and 80% concentration on plain carbon steel in 0.5 M H2SO4 solution was done by gravimetric measurement and statistical evaluation. Data output showed KF and TL extracts performed effectively at all concentrations studied with protection performance output generally above 80%. KL and BL extracts performed poorly at the lowest concentration while at higher concentrations optimal protection performance outputs are 74.41% and 83.53%. The protection performance outputs of KL, KF and TL extracts varied significantly with observation time due to thermodynamic instability and unstable inhibition behavior. BF extract exhibited stable inhibition behavior due to general stability of its protection performance outputs with respect to observation time. BF and KL exhibited the highest and lowest standard deviation due to the degree of variation of th...
IOP Conference Series: Materials Science and Engineering
The corrosion resistance of as-received and heat treated C26000 brass (annealed and quenched) was... more The corrosion resistance of as-received and heat treated C26000 brass (annealed and quenched) was evaluated by gravimetric analysis in 0.5 M, 1 M, 1.5 M, 2 M, 2.5 M, 3 M and 3.5 M HNO3 solution. Generally, corrosion rate of C26000 increased with increase in HNO3 concentration and varies significantly with respect to observation time. Results showed that heat treatment has no influence on the corrosion resistance of the brass heat treated brass compared to the as-received sample. Application of garlic extracts in HNO3 solution at 0.5 M significantly decreased the corrosion rate of C26000 60% concentration with inhibition value of 79.46%. The garlic extract exhibited significant concentration dependent behaviour and its inhibition performance varies with observation time. Statistical evaluation showed the standard deviation values of as-received and heat treated C26000 varied with respect to mean inhibition data. However, variation increased with HNO3 concentration due to thermodynami...
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Papers by Cleophas Loto