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Document Type |
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Thesis |
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Document Title |
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PhD thesis رسالة دكتوراه |
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Subject |
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A Study of Some Factors Affecting the Corrosion of SABIC Carbon Steel in Soil for Different Regions of Kingdom of Saudi Arabia |
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Document Language |
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English |
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Abstract |
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Influence of some factors (such as moisture content, temperature, soil treatment by sterilization or/and washing and inhibitor addition) affecting the corrosion behavior of SABIC carbon steel grade X60 (SCSX60) in soils for different regions of Kingdom of Saudi Arabia (Riyadh, Rabigh and Jeddah) was investigated using chemical and electrochemical measurements. Optical photograph and scanning electron microscopy also used to characterize the corrosion products formed on SCSX60 under the studied conditions. The results revealed that the corrosion rate of the studied soils increases with increasing soil moisture content up to maximum value at 10% moisture content, then tends to decrease at moisture content more than 10%. the results obtained from kinetic study showed that high corrosivity for the investigated soils under the studied conditions. Macroscopic observation of SCSX60 specimens showed that the produced corrosion patterns include uniform defects, pitted surfaces, striations, and channel defects. The corrosion products observed by SEM tend to confirm that the bacteria play an important role in the corrosion of SCSX60 in the studied soils. In each soil, the values of both and for SCSX60 electrode are shifted to more negative values with increasing moisture content, indicating that the corrosion rate of SCSX60 in the studied soils is moisture content dependent. The data obtained from chemical and electrochemical measurements at different moisture content levels revealed that the more frequent corrosivity order for the studied soils can be given as: Jeddah > Rabigh > Riyadh. Good correlation between the corrosivity order of the studied soils and soils variables was obtained. Electrochemical data for SCSX60 corrosion in the studied soils (10% moisture content) at different temperatures (30-60oC) revealed that the corrosion reaction was activated with increasing soil temperature and hence obeys Arrhenius equation. Various thermodynamic parameters ( , A, and ) for SCSX60 corrosion were estimated at each soil and well discussed. The results obtained from soil treatment by sterilization or/and washing illustrated that the rate of corrosion of SCSX60 was clearly decreased compared to untreated soil which varies according to the type of treatment process. For the various soil treatment, the corrosion rate of SCSX60 gives the following decreasing order: UT ˃ S ˃W˃ S-W. The soil treatment processes was found affect the physico-chemical properties of the studied soils with different extent. The effect of addition of three natural inhibitors obtained from plant origin (Matricaria Chamomilla, MC, Fenugreek, F, and Chili Pepper, CP) on the corrosion behavior of SCSX60 in the studied soils of 10% moisture content was investigated after 5 weeks of immersion and at ambient temperature (29 ±1oC) using weight loss method. It was found that the studied inhibitors are effective as corrosion inhibitors when used at high level of their concentration with the exception of MC inhibitor in Rabigh and Jeddah soils. In these two later cases a weak inhibition is detected at low concentration and an acceleration behavior is detected at high level of concentrations. Temkin adsorption isotherm was found to be the best adsorption model that fits the experimental inhibition data. |
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Supervisor |
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Dr. Ehteram Abdulla Mohammed Noor |
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Thesis Type |
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Doctorate Thesis |
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Publishing Year |
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1433 AH
2011 AD |
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Number Of Pages |
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257 |
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Added Date |
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Sunday, February 5, 2012 |
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Researchers
| عائشة حســين مبــاركي | Moubaraki, Aisha Hussain | Researcher | Master | ahm13988@hotmail.com |
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