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Materials Sciences and Applications 2016年第8期7卷 396-402页

作者： Joseph Yoeza Naimani Philip Joseph Buchweshaija Alinanuswe Mwakalesi Chemistry Department University of Dar es Salaam Dar es Salaam Tanzania Physical Sciences Department Sokoine University of Agriculture Morogoro Tanzania

In this study, corrosion inhibiting properties of amino pentadecylphenols (APPs) derived from Cashew Nut Shell Liquid (CNSL) on mild steel in aerated 0.10 M HCl at 303 K were studied using Electrochemical Impedance Spectroscopy (EIS) and potentiodynamic polarization measurements. Both methods indicated the potential of a mixture of amino pentadecyphenols to serve as a corrosion inhibitor in mild steel in 0.10 M HCl. Corrosion inhibition efficiencies were observed to increase with increase in the inhibitor concentration, with maximum corrosion inhibition of about 98% at inhibitor concentration of 600 ppm. The adsorption of the inhibitor on mild steel surface was found to obey Temkin adsorption isotherm, signifying physical adsorption of the inhibitor molecules on mild steel surface.

关键词： Corrosion Inhibitor Cashew Nut Shell Liquid Amino Pentadecylphenols mild steel

The Use of Models to Evaluate Corrosion Effects on mild steel Heat Exchanger in Water and Mono Ethanol Amine (MEA)

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Advances in Chemical Engineering and Science 2023年第4期13卷 336-350页

作者： Ojong Elias Ojong Jaja Zina Wosu Chimene Omeke Ana Anakri Ekpenyong Dadet Wilson Anaba Catherine Uloma Emenike Aguma Sedi Patrick Forwah Jacques Ndeh Department of Chemical Engineering Faculty of Engineering & Technology University of Calabar Calabar Nigeria Department of Chemical/Petrochemical Engineering Faculty of Engineering Rivers State University Port Harcourt Nigeria Department of Chemical Engineering Federal University Otuoke Otuoke Nigeria Department of Petroleum Engineering Faculty of Engineering & Technology University of Calabar Calabar Nigeria Department of Chemical Engineering University of Benin Benin Nigeria Department of Clinical Biochemistry and Immunology Faculty of Medical Laboratory Sciences University of Calabar Calabar Nigeria

Heat exchanger is an important equipment used in process industries for cooling and heating purposes. Its design configuration which involves the flow of cold and hot fluids within the exchanger subjects it to corrosion attack. The article utilized the principle of mass and energy conservation in the development of weight and temperature models to study the effect of corrosion on mild steel coupon inside the exchanger containing water and Mono ethanol amine (MEA). The models developed were resolved analytically using Laplace Transform and simulated using Excel as simulation tool and data obtained from experiment in the laboratory to obtain profiles of weight loss and temperature as a function of time. The weight loss and performance of mild steel under various corrosive conditions were examined which indicates the effect of corrosion on the mild steel heat exchanger in water and MEA media. The result shows that water is more corrosive than MEA at higher temperatures and at lower temperatures of 35°C and 1 atm, MEA has inhibitive properties than water as indicated by the weight loss result with time. The comparative analysis between the results obtained from the model simulation and experimental results shows that the result obtained from the model is more reliable and demonstrated better performance characteristics as it clearly shows mild steel heat exchanger experiences more corrosive effect in water medium than MEA at higher temperatures. And at lower temperatures, MEA becomes more inhibitive and less corrosive than water. The model simulation results correlate with various literatures and hence, it is valid for future referencing.

关键词： Model Corrosion Effect Heat Exchanger Simulation Media mild steel Coupon

Effect of Catharanthus roseus (Vince rosea) and Turmeric (Curcuma longa) Extracts as Green Corrosion Inhibitors for mild steel in 1 M HCl

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Materials Sciences and Applications 2016年第10期7卷 654-671页

作者： Rabab Mohamed Abou Shahba Abd El-Aziz El-Sayed Fouda Azza El-Sayed El-Shenawy Amina Salah Mohamed Osman Department of Chemistry Faculty of Science El-Azhar University Nasr city Egypt Department of Chemistry Faculty of Science El-Mansoura University El-Mansoura Egypt

The corrosion inhibition of mild steel by Catharanthus roseus (Vince rosea) and Turmeric (Curcuma longa) extracts as green inhibitors in 1 M HCl solutions has been investigated by using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), hydrogen evolution measurements and scanning electron microscope (SEM) techniques. Results obtained show that these investigated compounds are good inhibitors and act as mixed type inhibitors. The inhibition efficiencies increase with increasing inhibitor concentration. The SEM results show the formation of protective film on the mild steel surface in the presence of Catharanthus roseus and Turmeric extracts. The results obtained from different tested techniques are in good agreement.

关键词： Catharanthus roseus Extract Turmeric Extracts mild steel

Life Cycle Assessment of Household Water Tanks—A Study of LLDPE, mild steel and RCC Tanks

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Journal of Environmental Protection 2016年第5期7卷 760-769页

作者： Kunal N. Shah Nanik S. Varandani Monika Panchani Environment & Energy Efficiency Research Wing (E&EERW) Gujarat Energy Research and Management Institute (GERMI) Gandhinagar India

A case of household water tanks, 1000 L capacity, made of RCC, LLDPE and mild steel (stainless steel) was evaluated for life cycle analysis. The scope of the research comprised of the raw materials, energy inputs and corresponding emissions during all phases of product making such as extraction of raw material, it’s processing, followed by manufacturing and transport, as well as use and reuse of the product. Simapro 8 (System for Integrated environMental Assessment of PROducts), a modelling software, from Dutch PRé Consultants was used to conduct the life cycle analysis. Simapro 8 enables systematic and transparent modelling and analysis of complex life cycles based on the recommendations of the ISO 14040 series of standards. In the present study the most common method which is acceptable worldwide “Recipe Endpoint method” (ReCiPe) was employed. ReCiPe computes the impact categories and classifies them into two classes based on relevant arrays of characterization factors. Simapro addresses impact categories viz. ozone depletion, human toxicity, ionizing radiation, photochemical oxidant formation, particulate matter formation, terrestrial acidification, climate change, terrestrial ecotoxicity, agricultural land occupation, urban land occupation, natural land transformation, marine ecotoxicity, marine eutrophication, fresh water eutrophication, fresh water ecotoxicity, fossil fuel depletion, minerals depletion, fresh water depletion at the midpoint level. While at the Endpoint level, the impact categories are multiplied by corresponding damage factors and integrated to be represented as three Endpoint level categories, viz. human health, ecosystems and resource depletion. The three endpoint categories are normalized, weighted, and aggregated into a single score. LCA studies indicate that household water tanks of LLDPE have least environmental implications considering impacts on human health, ecosystems and resource depletion as compared to its counterparts viz. Househ

关键词： Life Cycle Assessment Water Tanks Linear Low-Density Polyethylene (LLDPE) RCC mild steel Recipe Endpoint Method

Ethanol Extract of Vitex Doniana as a Green Corrosion Inhibitor for mild steel in Hydrochloric Acid Medium

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Journal of Chemistry and Chemical Engineering 2012年第8期6卷 708-714页

作者： Onuegbu Theresa Uzoma Iloamaeke Ifeoma Maryjane Umoh EnoObong Thompson Aj iwe Vincent Ishmael Egbulefu Umedum Ngozi Lilian Department of Pure and Industrial Chemistry Nnamdi Azikiwe University Anambra State 5025 Nigeria Superintendent Water and Special Chemicals Section Research and Development Division Nigerian National PetroleumCorporation Rivers State 53 73 Nigeria

Corrosion is a costly and complicated problem facing mild of Vitex doniana as a corrosion inhibitor for mild steel in HCI medium steel utility. This study investigated the use of ethanol extract Experimental methods used are gravimetric and thermometric The results showed that corrosion rate decreased as the concentration of ethanol extract of Vitex doniana increased and with decrease in temperature. Vitex doniana extract obeyed Langmuir and Tempkin adsorption isotherm. Physical adsorption was proposed from △G° and Ea. Inhibition efficiency （1%） and the degree of surface coverage （0） were calculated and all indicated that Vitex doniana was a good corrosion inhibitor.

关键词： Corrosion inhibition mild steel vitex doniana extract.

Kinetics of Atmospheric Corrosion of mild steel in Marine and Rural Environments

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Journal of Marine Science and Application 2015年第1期14卷 105-112页

作者： S. Palraj M. Selvaraj K. Maruthan M. Natesan CSIR-Central Electro Chemical Research Institute Karaikudi 630006 India

In continuation of the extensive studies carried out to update the corrosion map of India, in this study, the degradation of mild steel by air pollutants was studied at 16 different locations from Nagore to Ammanichatram along the east coast of Tamilnadu, India over a period of two years. The weight loss study showed that the mild steel corrosion was more at Nagapattinam site, when compared to Ammanichatram and Maravakadu sites. A linear regression analysis of the experimental data was attempted to predict the mechanism of the corrosion. The composition of the corrosion products formed on the mild steel surfaces was identified by XRD technique. The corrosion rate values obtained are discussed in the light of the weathering parameters, atmospheric pollutants such as salt content ＆ SO2 levels in the atmosphere, corrosion products formed on the mild steel surfaces.

关键词： Kinetics atmospheric corrosion mild steel XRD weight loss

Development of a Predictive Model to Improve the Hardness of mild steel Welded Joint

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Engineering（科研） 2021年第4期13卷 215-223页

作者： O. O. Ogbeide L. M. Ebhota Department of Production Engineering University of Benin Benin City Nigeria Groove Engineering & Integrated Services Limited Lagos Nigeria

Structural integrity of weldment is greatly influenced by its process parameters and usually, it is expected for a welded joint to be stronger than its parent metal, but in actual fact, most failures occur at the welded joints and it is mostly due to poor combination of process parameters or inexperience of the welder. This poor combination leads to poor hardness exhibited at the welded joint. The aim of this study is to predict and improve the hardness of mild steel welded zone using the tungsten inert gas (TIG) welding process. Response Surface Methodology (RSM) was employed to analyze the welded response. 200 pieces of mild steel coupons measuring 27.5 × 10 × 10 mm were prepared and used for the experiment, the experiment was performed 20 times, using 5 specimens for each run, after which the hardness was measured and results analyzed respectively. The study produced eighteen (18) optimum results with the best selected to produce a material hardness of 299.269 N/mm2 with desirability of 95.6%, resulting from current of 120 amp, voltages of 20 and gas flow rate of 12 L/min.

关键词： RSM TIG mild steel Contour Plot

Origanum majorana Extracts as mild steel Corrosion Green Inhibitors in Aqueous Chloride Medium

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Journal of Environmental Protection 2016年第4期7卷 532-544页

作者： Hassen Challouf Nébil Souissi Mhamed Ben Messaouda Rym Abidi Adel Madani Tunis El Manar University Institut Préparatoire aux Etudes d’Ingénieurs El Manar Campus Universitaire El Manar Tunis Tunisia Carthage University Faculté des Sciences de Bizerte Laboratoire de Recherche “Application de la Chimie aux Ressources et Substances Naturelles et à l’Environnement” Jarzouna Tunisia Carthage University Institut Préparatoire aux Etudes Scientifiques & Techniques Laboratoire de Recherche “Matériaux Molécules et Applications” La Marsa Tunisia Carthage University Faculté des Sciences de Bizerte Laboratoire de Physique des Matériaux Jarzouna Tunisia

We optimized Origanum majorana (OM) extraction for mild steel corrosion inhibition in neutral 0.5 M chloride medium. The inhibition mechanism evolved in presence of the optimal extract was discussed when calculating the activation energy (Ea), the activation enthalpy (ΔaH) as well as the activation entropy (ΔaS). The OM extract molecules were investigated using the density functional theory (DFT) at B3LYP/6-31G(d,p) basis set level. 1-methyl-4-propan-2-ylcyclohexa-1,3-diene alpha-terpinene was predicted exhibiting the most inhibition capabilities.

关键词： Origanum majorana Corrosion Inhibition mild steel NaCl

Investigation of Aloe lateritia Gel as Corrosion Inhibitor for mild steel in 2 M HNO₃ and 1 M H₂SO₄ Media

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Journal of Minerals and Materials Characterization and Engineering 2016年第1期4卷 33-39页

作者： Lucas Paul Revocatus L. Machunda Department of Materials and Energy Science & Engineering Nelson Mandela African Institution of Science and Technology Arusha Tanzania Department of Water and Environmental Science and Engineering Nelson Mandela African Institution of Science and Technology Arusha Tanzania

Corrsion inhibition of Aloe lateritia gel for mild steel in 2 M HNO3 and 1 M H2SO4 solutions was investigated by potentiodynamic polarization, Scanning electron microscopy (SEM) and Foutier transform infrared (FT-IR). Inhibition efficiency increased with the increase of the concentration of the gel. The optimal concentration of the gel gives maximum inhibition efficiency of 77.4% and 70.3% in 1 M H2SO4 and 2 M HNO3 respectively. Polarization plots shows that, the gel works as a mixed type inhibitor altering both cathodic and anodic reaction. SEM proves the uniform and pitting corrosion at the surface of mild steel in 1 M H2SO4 and 2 M HNO3 respectively. Using FT-IR potential function groups from pure gel and some stretch shift was observed from corrosion product and some stretch shift from corrosion products was observed.

关键词： Corrosion Inhibitor mild steel Potentiodynamic Polarization Sulfuric Acid Nitric Acid

The Effect of Electrochemical Polishing Time on Surface Topography of mild steel

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International Journal of Plant Engineering and Management 2006年第3期11卷 145-150页

作者： WANG Bao-cheng ZHU Jin-hua State Key Laboratory of Mechanical Behavior of Metal Material Xi＇an Jiaotong University Xi＇an 710049 P. R. China College of Material Science and Engineering Taiyuan University of TechnologyTaiyuan 030024 P.R. China

This paper investigated the variation of the altitude density function （ADF） and the autocorrelation function （ ACF） about the surface profile of mild steel during electrochemical polishing （ECP）. The results show that the variation features of ADF with polishing time are fiat-steep-fiat, and the variation features of A CF with polishing time are random-regular-random. There is a fine surface smoothness at the special period of ECP. Both the original surface and the full ECP surface show an obvious roughness.

关键词： mild steel electrochemical polishing altitude density function autocorrelation function