Dissertations / Theses: 'Mild steel – Corrosion'

1

Tran, Thu N. B. "Corrosion Mechanisms of Mild Steel in Weak Acids." Ohio University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1400078277.

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2

Navabzadeh, Esmaeely Saba. "Galvanic Localized Corrosion of Mild Steel under Iron Sulfide Corrosion Product Layers." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou151551709542735.

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3

Abdul-Salam, Ezzet Hameed. "Fatigue crack propagation in mild steel." Thesis, University of Salford, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.291749.

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4

Wang, Shufan. "Effect of oxygen and CO₂ corrosion of mild steel." Ohio : Ohio University, 2009. http://www.ohiolink.edu/etd/view.cgi?ohiou1235976914.

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5

Wang, Shufan. "Effect of Oxygen on CO2 Corrosion of Mild Steel." Ohio University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1235976914.

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6

Rihan, Rihan Omar. "Erosion-corrosion of mild steel in caustic and inhibited acid solution /." [St. Lucia, Qld.], 2001. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16325.pdf.

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7

Cheung, Chin Wa Sunny. "Biofilms of marine sulphate-reducing bacteria on mild steel." Thesis, University of Portsmouth, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241657.

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8

Brown, Bruce N. "The Influence of Sulfides on Localized Corrosion of Mild Steel." Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1386325647.

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9

Prieto, Nieto Claudia L. "Mechanical Characteristics and Adherence of Corrosion Products on Mild Steel." Ohio University / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1574678745737727.

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10

Yang, Yuan Feng. "Calcium and magnesium containing anti-corrosion films on mild steel." Thesis, University of Manchester, 2010. https://www.research.manchester.ac.uk/portal/en/theses/calcium-and-magnesium-containing-anticorrosion-films-on-mild-steel(34a7b76f-8ba6-49a7-a1fa-d87f52dc230f).html.

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Under normal conditions, cathodically protected mild steel in seawater is protected by a precipitated film of calcium carbonate and magnesium hydroxide, the so-called calcareous film. This study has attempted to investigate the dynamics of calcareous deposit formation during cathodic protection and the composition of calcareous deposits formed under different applied current densities, and also the role played by the initial current density in forming a good quality calcareous deposit. In addition, an under protection situation can occur where current demand values are under estimated, or where structures are approaching the end of their design lives. In these conditions, a calcareous film might well occur but complete protection is probably not possible. These situations have also been studied. At low insufficient current densities where steel corrosion is still occurring, a clear correlation exists between the iron containing corrosion product and the overlaying magnesium hydroxide layer. Such effects have also been investigated using pH titration analysis, where the effect of co-precipitation of the iron and magnesium oxides/hydroxides has been shown. At higher current densities a layered precipitate has been shown to occur consisting of an inner magnesium containing layer and an outer calcium containing layer. At obvious overprotection current densities, the mechanical stresses involved in hydrogen evolution are assumed to give rise to film cracking. To augment and compliment the study on calcareous calcium/magnesium films formed during cathodic protection, a calcium-magnesium containing pigment has also been investigated in aqueous solutions at open circuit as a possible corrosion inhibitor. Another study looked at the same inhibitor in conjunction with a sacrificial zinc anode. Very effective inhibition has been shown with the film containing not only magnesium, calcium and phosphorous but also zinc. In all the investigations electrochemical methods have been used together with various surface analytical techniques.

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11

Holloway, Mark. "Corrosion of steel reinforcement in slag-based concrete." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365811.

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12

Abosrra, L. R. "Corrosion of steel reinforcement in concrete : corrosion of mild steel bars in concrete and its effect on steel-concrete bond strength." Thesis, University of Bradford, 2010. http://hdl.handle.net/10454/5417.

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This thesis reports on the research outcome of corrosion mechanism and corrosion rate of mild steel in different environments (saline, alkaline solutions and concrete media) using potentiodynamic polarization technique. The study also included the effect of corrosion on bond strength between reinforcing steel and concrete using pull-out test. Corrosion of mild steel and 316L stainless steel with different surface conditions in 1, 3 and 5% saline (NaCl + Distilled water) was investigated. Specimens ground with 200 and 600 grit silicon carbide grinding paper as well as 1μm surface finish (polished with 1μm diamond paste) were tested. In case of mild steel specimens, reduction in surface roughness caused increase in corrosion rate, while in 316L stainless steel corrosion rate decreased as the surface roughness improved. Metallographic examination of corroded specimens confirmed breakdown of passive region due to pitting corrosion. Corrosion of mild steel was also investigated in alkaline solution (saturated calcium hydroxide, pH =12.5) contaminated with 1, 3 and 5% saline. A series of corrosion experiments were also conducted to examine the efficiency of various concentrations of calcium nitrite (CN) on corrosion behaviour of both as-received and polished mild steel in alkaline solution containing 3% saline after 1 hour and 28 days of exposure. Corrosion rate was higher for the as-received than polished mild steel surface under the same testing conditions in NaCl alkaline solution with and without nitrites due to the effect of surface roughness. Morphology investigation of mild steel specimens in alkaline solution ii containing chlorides and nitrites showed localized pits even at nitrite concentration equal to chloride concentration. Corrosion of steel bars embedded in concrete having compressive strengths of 20, 30 and 46MPa was also investigated. The effect of 2 and 4% CN by weight of cement on corrosion behaviour of steel bar in low and high concrete strengths specimens were also studied. All reinforced concrete specimens were immersed in 3% saline solution for three different periods of 1, 7 and 15 days. In order to accelerate the chemical reactions, an external current of 0.4A was applied. Corrosion rate was measured by retrieving electrochemical information from polarization tests. Pull-out tests of reinforced concrete specimens were then conducted to assess the corroded steel/concrete bond characteristics. Experimental results showed that corrosion rate of steel bars and bond strength were dependent on concrete strength, amount of CN and acceleration corrosion period. As concrete strength increased from 20 to 46MPa, corrosion rate of embedded steel decreased. First day of corrosion acceleration showed a slight increase in steel/concrete bond strength, whereas severe corrosion due to 7 and 15 days corrosion acceleration significantly reduced steel/concrete bond strength. Addition of only 2% CN did not give corrosion protection for steel reinforcement in concrete with 20MPa strength at long time of exposure. However, the combination of good quality concrete and addition of CN appear to be a desirable approach to reduce the effect of chloride induced corrosion of steel reinforcement. At less time of exposure, specimens without CN showed higher bond strength in both concrete mixes than those with CN. After 7 days of corrosion acceleration, the higher concentration of CN gave higher bond strength in both concrete mixes. The same trend was observed at 15 days of corrosion acceleration except for the specimen with 20MPa compressive strength and 2% CN which recorded the highest deterioration in bond strength.

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13

Ahmed, Mohamed. "Inhibition of mild steel corrosion in cooling systems by low- and non-toxic corrosion inhibitors." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/inhibition-of-mild-steel-corrosion-in-cooling-systems-by-low-and-nontoxic-corrosion-inhibitors(7dc2367d-7352-4ab2-85b1-39b09d6487d8).html.

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The aim of the research in this thesis was to study how environmentally friendly corrosion inhibitors for cooling water systems might be developed and used. Firstly, reduced toxicity inorganic corrosion inhibitors (i.e. nitrite/molybdate) were considered. Secondly, non-toxic inhibitors based on mono and di-basic salts of carboxylic acids were studied systematically as a function of carbon chain length. For nitrite inhibitor alone, a concentration of 7 mM NaNO2 was effective to inhibit carbon steel in chloride media of 10 mM NaCl, while 10 mM nitrite was needed in sulphate media of 3.66 mM Na2SO4. However, it was found possible to significantly reduce the concentration of nitrite by adding molybdate in synergy. This was attributed to the nitrite passivation combined with ferrous molybdate salt film pore plugging thus promoting a continuous and protective film on the material within these media. Thus, in pH 6-10 an inhibition efficiency of 97% was recorded with a mixture of 3 mM nitrite/2 mM molybdate in both chloride and sulphate media and at 25°C and 60°C. However as the solution pH decreased below pH 4 the inhibition efficiency decreased to about 47%.In the second part of the study, the use of sodium salts of carboxylic acids with different chain lengths has been investigated. In this part a summary of the performances and limitations of both mono- and di-sodium carboxylate inhibitors are presented. For mono-carboxylates, the inhibition efficiency reached a maximum value of 95% in stagnant aerated solutions at a chain length of C=4 with a critical inhibition concentration of 6 mM in 10 mM NaCl solution. However the inhibition efficiency gradually decreased as the number of carbon atoms in the chain length increased to more than 8, or less than 4, and this was in agreement with surface hydrophobicity and contact angle results. For lower chain lengths, the carboxylate anion becomes more acidic and complexing of the metal ion while for longer chain lengths, the carboxylate anion becomes less soluble and tends to micellise wherby the active groups are no longer available for surface adsorption. For di-carboxylates the inhibition efficiency improved in 10 mM NaCl at a given chain length compared with mono-carboxylates, and continued to increase to C=8 (sebacate), which achieved excellent inhibition efficiency. However, sebacate is costly so a blend with ethyl hexanoate was found to be economically favoured.

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14

Tavassoli-Salardini, Fereshteh, of Western Sydney Nepean University, and Faculty of Science and Technology. "Inhibition of mild steel corrosion in aqueous media with sodium propionate." THESIS_FST_XXX_TavassoliSalardini_F.xml, 1996. http://handle.uws.edu.au:8081/1959.7/233.

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The potential use of sodium propionate as a corrosion inhibitor for mild steel in aqueous media is investigated using a range of electrochemical and surface analytical techniques. The use of sodium propionate for the inhibition of mild steel corrosion is discussed, and the effective pH range of sodium propionate using various buffers is investigated. The effectiveness of sodium propionate as an inhibitor for mild steel pitting corrosion in the presence of various concentrations of CI- is studied. The effect of some oxidants, IO3-, BrO3-, NO32- on the anodic behaviour of mild steel in deaerated 0.01M carboxylate solutions of acetate, propionate, formate, succinate and salicylate is investigated. The critical temperature for effective inhibition of mild steel corrosion with sodium propionate is established, and the chemical composition of the film formed on mild steel surface in sodium propionate solution is studied using surface sensitive Fourier transform infrared spectroscopy FTIR. The efficiency of sodium propionate is compared to that of conventional inhibitors and a mechanism for the inhibition of mild steel corrosion with sodium propionate is proposed.
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15

Tavassoli-Salardini, Fereshteh. "Inhibition of mild steel corrosion in aqueous media with sodium propionate /." View thesis, 1996. http://library.uws.edu.au/adt-NUWS/public/adt-NUWS20030901.133617/index.html.

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16

Snowden, M. E. "Studies of corrosion inhibitors for the conservation of mild steel artefacts'." Thesis, University of Portsmouth, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247648.

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17

Li, Youlin. "Erosion-corrosion of ductile materials by aqueous slurries." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.360883.

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18

Mohamed, Mohd Farid. "Water Chemistry and Corrosion Inhibition in High Pressure CO₂ Corrosion of Mild Steel." Ohio University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1429223819.

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19

Watkins, Peter Gareth. "The corrosion of mild steel in the presence of two isolates of marine sulphate reducing bacteria." Thesis, University of Portsmouth, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340914.

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20

Xu, Lichong. "Anaerobic corrosion of mild steel in seawater induced by sulfate-reducing bacteria (SRB)." Hong Kong : University of Hong Kong, 2001. http://sunzi.lib.hku.hk:8888/cgi-bin/hkuto%5Ftoc%5Fpdf?B2327315x.

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21

徐立沖 and Lichong Xu. "Anaerobic corrosion of mild steel in seawater induced by sulfate-reducing bacteria (SRB)." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2001. http://hub.hku.hk/bib/B31242546.

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22

Lee, Chi-Ming. "Pitting corrosion inhibition of mild steel by sodium molybdate and sodium silicate." Thesis, University of Nottingham, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292172.

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23

Han, Jiabin. "Galvanic Mechanism of Localized Corrosion for Mild Steel in Carbon Dioxide Environments." Ohio University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1258393107.

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24

Ning, Jing. "The Role of Iron Sulfide Polymorphism in Localized Corrosion of Mild Steel." Ohio University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1476660078407962.

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25

Howes, Thomas Edward. "Erosion-oxidation of mild steel in a fluidized bed environment." Thesis, University of Cambridge, 1997. https://www.repository.cam.ac.uk/handle/1810/253786.

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This thesis is a contribution to research into erosion-corrosion investigating the rapid wastage of in-bed heat exchanger tubing in fluidized bed combustors. Two main new areas of research were investigated; erosion-corrosion of mild steel in a temperature gradient and erosion-corrosion modelling. It has been suggested that differences between the wastage behaviour measured in fluidized bed combustors and laboratory studies is due to laboratory tests being carried out isothermally (specimen and fluidized bed at the same temperature) whereas, in a FBC boiler, the fluidized bed is considerably hotter than the metal heat exchanger tubing. The fluidized bed test rig was modified to increase the temperature gradient between the specimen and the fluidized bed from initial tests conducted by Rogers (1992b). Tests were carried out over a range of bed temperatures (300-500° C) and cooled specimen surface temperatures (175-500° C) with a maximum temperature difference between the two of 250° C. It was discovered that the temperature of the wear scar during a test was up to 200° C hotter than the temperature at the back of the specimen where the specimen temperature was initially measured in tests by Rogers (1992b). After temperature calibration tests the wastage of the specimens in a temperature gradient were very similar to the wastage of specimens exposed isothermally at the same metal temperature. Short term oxidation experiments were conducted on mild steel to obtain oxidation kinetics for erosion-corrosion modelling. It was found that the initial apparent parabolic rate constant was an order of magnitude larger than at longer time. Erosion studies were conducted with the aim to obtain quantitative data on the particle flux and the erosive behaviour of the bed with temperature. Results were not accurate enough to yield quantitative data but provided an estimate of the particle flux in the fluidized bed test rig. Results obtained from the short term oxidation and erosion studies were used in simple erosion-oxidation models to construct erosion-corrosion regime maps which tended to predict metal erosion to higher temperatures than observed experimentally. Predictions of material wear from the combination of an oxide removal and spalling mechanism predicted sensible wastage rates which agreed with experimental results.

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26

Hazzaa, M. I. "Synergistic effects in the inhibition by chromate-containing mixtures of the corrosion of mild steel." Thesis, University of Manchester, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380533.

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27

Huang, Jin. "Mechanistic Study of Under Deposit Corrosion of Mild Steel in Aqueous Carbon Dioxide Solution." Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1385569495.

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28

Gao, Shujun. "Thermodynamics and Kinetics of Hydrogen Sulfide Corrosion of Mild Steel at Elevated Temperatures." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1528836064560164.

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29

Kerr, C. "Electrochemical porosity testing of electroless nickel coatings on mild steel substrates." Thesis, University of Portsmouth, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.484205.

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30

Chokshi, Kunal K. "A study of inhibitor-scale interaction in carbon dioxide corrosion of mild steel." Ohio : Ohio University, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou1089819131.

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31

Tanupabrungsun, Tanaporn. "Thermodynamics and Kinetics of Carbon Dioxide Corrosion of Mild Steel at Elevated Temperatures." Ohio University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1355328679.

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32

Chokshi, Kunal. "A Study of Inhibitor-Scale Interaction in Carbon dioxide Corrosion of Mild Steel." Ohio University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1089819131.

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33

Huang, Lei. "Investigation of Environmental Effects on Intrinsic and Galvanic Corrosion of Mild Steel Weldment." Ohio University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1338567512.

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34

Zhang, Wei. "Initiation and Propagation of Localized Corrosion of Mild Steel in Marginally Sour Environments." Ohio University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1605039352183903.

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35

Mansoori, Hamed. "Influence of Calcium and Magnesium Ions and their Carbonate Scales on CO2 Corrosion of Mild Steel." Ohio University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1578414196892282.

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36

Loto, CA, and API Popoola. "Effect of Tobacco and Kola Tree Extracts on the Corrosion Inhibition of Mild Steel in Acid Chloride." International Journal of Electrochemical Science, 2011. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000675.

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Corrosion and inhibitor protection of mild steel specimens immersed in acid chloride solution was investigated 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 tobacco in different concentrations were used as ‘green’ inhibitors. This paper reports the results obtained from the weight loss method, calculated corrosion rates and the observed electrochemical response from the electrochemical potential monitoring of the mild steel during the experiments. A reduction in the active corrosion reactions behaviour of the mild steel test specimens in the strong acid chloride was obtained with the addition of different concentrations of the plants extracts. There was a drastic reduction in the weight loss and in the corrosion rate of the test samples. This behaviour 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 mild steel was achieved in nearly all the extracts for the greater part of the experimental period. However, the most effective results were obtained from the tobacco extract and also from the extract of kola leaf.

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37

Benham, T. J. "Some effects of carbon dioxide based atmospheres on the fretting of mild steel." Thesis, University of Nottingham, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357758.

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38

Lee, Kun-Lin John. "A mechanistic modeling of CO₂ corrosion of mild steel in the presence of H₂S." Ohio : Ohio University, 2004. http://www.ohiolink.edu/etd/view.cgi?ohiou----------.

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39

Baker, A. T. "The corrosion of pure iron and mild steel in gases containing both oxygen and sulphur." Thesis, University of Manchester, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.355898.

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40

George, Keith. "ELECTROCHEMICAL INVESTIGATION OF CARBON DIOXIDE CORROSION OF MILD STEEL IN THE PRESENCE OF ACETIC ACID." Ohio University / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1049297358.

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41

Ruzic, Vukan. "Mechanisms of protective FeCO₃ film removal in single-phase flow-accelerated CO₂ corrosion of mild steel /." [St. Lucia, Qld.], 2005. http://adt.library.uq.edu.au/public/adt-QU20060626.102924/index.html.

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42

Suhor, Muhammad Firdaus. "Effect of Iron Carbonate Deposition on Mild Steel Corrosion in High Partial Pressure Carbon Dioxide Systems." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1532376719359574.

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43

Babic, Marijan. "Role of Interfacial Chemistry on Wettability and Carbon Dioxide Corrosion of Mild Steels." Ohio University / OhioLINK, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1483543296145156.

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44

Kahyarian, Aria. "Mechanism and Prediction of Mild Steel Corrosion in Aqueous Solutions ContainingCarboxylic Acids, Carbon Dioxide, and Hydrogen Sulfide." Ohio University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1541154736282768.

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45

Maguire, Sarah. "An investigation into the COâ†2 corrosion of mild steel using conventional electrochemical techniques and high resolution microscopy." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246221.

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46

Mohammed, Nor Azmi. "The Effect of Turbulent Flow on Corrosion of Mild Steel in High Partial CO₂ Environments." Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1363706400.

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47

Díaz, Jorge G. "Effect of Amines as Corrosion Inhibitors for a Low Carbon Steel in Power Industry." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4666/.

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Commonly used amines in power industry, including morpholine, DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), and DMA (dimethylallylamine) were evaluated for their effect on AISI 1018 steel at 250oF. Samples were exposed to an autoclave containing amine added aqueous solution at pH of 9.5 for 1, 2, 4, 6, 8, and 12 hours. Morphology studies were carried using scanning electron microscope (SEM), phase analysis was done utilizing Fourier transform infrared spectroscopy (FTIR), and weight loss was performed to assess kinetics of oxidation. Control samples showed the highest metal dissolution rate. DBU showed the best performance in metal protection and SEM indicated the presence of a free-crack layer formed by fine particles in that set. FTIR showed that DBU apparently favored the formation of magnetite. It is believed that fine particles impede intrusion of aggressive ions into the metal surface by forming a barrier layer. FTIR demonstrated that DMA formed more oxyhydroxides, whereas morpholine presented magnetite to hematite transformation as early as 2 hours. SEM revealed that control and DMA produced acicular particles characteristic of oxyhydroxides while morpholine and DBU presented more equiaxed particles.

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48

Bin, Hussin Mohd Hazwan. "Extraction, modification and characterization of lignin from oil palm fronds as corrosion inhibitors for mild steel in acidic solution." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0135/document.

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La biomasse lignocellulosique en Malaisie peut être considérée comme l'une des sources d'énergie renouvelable prometteuse. Elle est principalement composée de cellulose, d'hémicellulose et de lignine et est adaptée pour des applications dans les domaines de l'énergie et de la chimie en raison de sa disponibilité suffisante, de son faible coût et de son caractère renouvelable. La production de biomasse lignocellulosique en Malaisie est considérée comme élevée et est issue en grande partie de l'industrie de l'huile de palme (environ 60 millions de tonnes de déchets d'huile de palme sont générés en un an). Les déchets de l’industrie de l'huile de palme pourraient être utilisés comme ressources alternatives pour la production de papier et de carton. Cependant, dans ce contexte, d'énormes quantités de lignine seraient rejetées (par l'industrie des pâtes et papier) en raison du manque de prise de conscience de son potentiel. Avec une teneur élevée en groupes fonctionnels divers (-OH phénoliques et aliphatiques, les carbonyles, les carboxyles, etc.), la lignine pourrait être utilisée en substitution de produits actuels dans des applications industrielles telles que l'inhibition de la corrosion des métaux et alliages. Les frondes de palmier à huile (OPF) étant l'un des plus gros contributeurs de déchets de biomasse en Malaisie, elles ont donc été utilisées comme matière première dans cette étude. Afin d'améliorer l'extractabilité de la lignine et ses propriétés, l'extraction a été effectuée de différentes façons (par délignification directe et / ou des méthodes de pré-traitement combiné). Cependant, la forte hydrophobicité de la lignine limite sa capacité à agir comme inhibiteur de corrosion efficace. Par conséquent, des modifications de la structure de la lignine OPF ont été effectuées de deux manières ; (1) en incorporant des piégeurs de recondensation de la lignine (2-naphtol et 1,8-dihydroxyanthraquinone) pendant le prétraitement par autohydrolyse avant le traitement organosolv (pourcentage de rendement de la lignine: AHN EOL = 13,42 ± 0,71% et AHD EOL = 9,64 ± 0,84%) et (2) le fractionnement de la lignine à partir de procédés de délignification directs (Kraft, à la soude et organosolv) par l'intermédiaire d'une technique d'ultrafiltration à membrane (rendement en pourcentage de fractions de lignine perméat: Kraft = 5,41 ± 2,04%; soude = 12,29 ± 0,54% et organosolv = 1,48 ± 0,15%). Les propriétés physiques et chimiques des lignines modifiées ont été évaluées en utilisant l'infrarouge à transformée de Fourier (FTIR), la résonance magnétique nucléaire (RMN), chromatographie par perméation de gel (GPC), l'analyse thermique et la Chromatographie liquide à haute performance (HPLC). Des fractions de lignine modifiée présentant des teneurs en OH phénoliques élevées, des poids moléculaires, polydispersité et contenus en OH aliphatiques faibles ont abouti à des valeurs plus élevées de l'activité antioxydante. L'activité antioxydante semble être dépendante de la teneur en OH phénolique et en ortho-méthoxyle, grâce à la stabilité du radical formé et la capacité de réduire les ions Fe3+ en Fe2+ ions. En effet, les propriétés physico-chimiques améliorées et une activité anti-oxydante de lignine modifiée a donné une corrélation positive avec l'inhibition de la corrosion de l'acier doux dans l'action solution de HCl 0,5 M qui a été évaluée par spectroscopie d'impédance électrochimique (SIE), de polarisation et de la perte de poids mesure potentiodynamique. La meilleure efficacité de pourcentage d'inhibition (ex: 81 à 90%) a été obtenu à la concentration de 500 ppm pour les inhibiteurs de la lignine, mais a diminué avec l'augmentation de la température (303 à 333 K). Les données thermodynamiques indiquent que l'adsorption de la lignine modifiée sur l'acier doux a été spontanée et que les inhibiteurs ont été principalement adsorbés physiquement (physisorption), ce résultat étant confirmé par l'énergie d'activation de l'adsorption, Ea. [...]
Lignocellulosic biomass in Malaysia can be considered as one of the promising sources of renewable energy. It is mainly composed of cellulose, hemicellulose, and lignin and best-suited for energy and chemical applications due to its sufficient availability, inexpensive and is sustainable. In general, the production of lignocellulosic biomass in Malaysia was considered high and mainly derived from the palm oil industries (approximately 60 million tonnes of oil palm waste were generated in a year). The oil palm biomass waste could possibly be used as alternative resources for the production of paper and cardboard. However, massive amounts of lignin by-product could also be discarded in huge quantities (by the pulp and paper industry) due to lack of awareness on its potential. Having high content of diverse functional groups (phenolic and aliphatic –OH, carbonyls, carboxyls, etc.) and phenylpropanoid structure, lignin can lead to substitutes in industrial applications such as in corrosion inhibition of metals and alloys. Since the oil palm fronds (OPF) are one of the largest biomass waste contributors in Malaysia, it was therefore used as raw material in this study. In order to improve the lignin extractability and properties, the extraction was conducted in different ways (via direct delignification and/or combined pretreatment methods). Due to the high hydrophobicity of lignin, it limits the capability to act as efficient corrosion inhibitors. Hence, modifications of the OPF lignin structure were conducted in two ways; (1) by incorporating organic scavengers (2-naphthol and 1,8-dihydroxyanthraquinone) during autohydrolysis pretreatment before organosolv treatment (percentage yield of lignin: AHN EOL = 13.42±0.71 % and AHD EOL = 9.64±0.84 %) and (2) fractionation of lignin from direct delignification processes (Kraft, soda and organosolv) via ultrafiltration membrane technique (percentage yield of permeate lignin fractions: Kraft = 5.41±2.04 %; soda = 12.29±0.54 % and organosolv = 1.48±0.15 %). The physical and chemical properties of the modified lignins were evaluated by using Fourier Transform Infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, gel permeation chromatography (GPC), thermal analysis and high performance liquid chromatography (HPLC). Modified lignin fractions with higher phenolic –OH content but lower molecular weight, polydispersity as well as aliphatic –OH content resulted in higher values of antioxidant activities. The antioxidant activity seems be dependent on the increase of their free phenolic –OH and ortho-methoxyl content, through the stability of the radical formed and the ability to reduce Fe3+ ions to Fe2+ ions. Indeed, the improved physicochemical properties and antioxidant activity of modified lignin gave positive correlation with the mild steel corrosion inhibition action in 0.5 M HCl solution that were evaluated by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss measurements. The best percentage of inhibition efficiencies (IE: 81 – 90 %) were attained at the concentration of 500 ppm for all lignin inhibitors but decreased with the increase in temperature (303 – 333 K). Thermodynamic data indicated that the adsorption of the modified lignin onto the mild steel was spontaneous and the inhibitors were mainly physically adsorbed (physiosorption), supported by the activation energy of adsorption, Ea. The enhanced protective properties of the modified lignin will pave way for an alternative approach for the utilization of these natural waste materials

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Lee, Kun-Lin John. "A Mechanistic Moceling of CO₂ Corrosion of Mild Steel in the Presence of H₂S." Ohio University / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1108130173.

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50

Akhtar, Mst Alpona. "Hydrophobicity of Magnetite Coating on Low Carbon Steel." Thesis, University of North Texas, 2018. https://digital.library.unt.edu/ark:/67531/metadc1248389/.

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Superhydrophobic coatings (SHC) with excellent self-cleaning and corrosion resistance property is developed on magnetite coated AISI SAE 1020 steel by using a simple immersion method. Roughness measurement, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), contact angle measurement (CAM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), potentiodynamic polarization test, electrochemical impedance spectroscopy (EIS), and qualitative characterization of self-cleaning behavior, antifouling property and durability of the coatings are assessed. A water contact angle as high as 152o on the coated surface with excellent self-cleaning and resistivity to corrosion and good longevity in atmospheric air is obtained. Self-cleaning test results prove that these surfaces can find applications in large scale production of engineering materials. Potentiodynamic polarization tests and EIS tests confirm that the superhydrophobic low carbon steel surfaces have better resistance to corrosion compared to bare steel and magnetite coated steel in 3.5% NaCl solution. But the longevity of the coated steel surfaces in 3.5% salt solution is limited, which is revealed by the immersion durability test. However, hydrophobic coatings (HC) have better stability in normal tap water, and it can stay unharmed up to 15 days. Finally, hydrophobic coatings on low carbon steel surface retains hydrophobic in open atmosphere for more than two months. Results of this investigation show surface roughness is a critical factor in manufacturing hydrophobic steel surfaces. Higher contact angles are obtained for rougher and more uniform surfaces. A linear mathematical relationship (y =6x+104; R2 = 0.93) is obtained between contact angle (y) and surface roughness (x).

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