Search for: steel-corrosion
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    The enhancing power of iodide on corrosion prevention of mild steel in the presence of a synthetic-soluble Schiff-base: Electrochemical and surface analyses

    , Article Electrochimica Acta ; Volume 55, Issue 20 , August , 2010 , Pages 6058-6063 ; 00134686 (ISSN) Lashgari, M ; Arshadi, M. R ; Miandari, S ; Sharif University of Technology
    The inhibitory action of N,N′-1,3-propylen-bis(3- methoxysalicylidenimine) {PMSI} on mild steel corrosion in sulfuric acid medium was investigated through electrochemical methods and evaluations based on infrared spectroscopy and scanning electron micrographs. The studies revealed that the molecule is a good mixed-type inhibitor (mostly anodic), acts as a multi-dentate ligand and repels the corrosive agents by hydrophobic forces. Its adsorption on metal surface has a physicochemical nature and obeys the Langmuir isotherm. At a critical (optimum) concentration, an anomalous inhibitory behavior was observed and interpreted at microscopic level by means of desorption/adsorption process and... 

    The effect of gas mixture of post-oxidation on structure and corrosion behavior of plasma nitrided AISI 316 stainless steel

    , Article Applied Surface Science ; Volume 283 , 2013 , Pages 584-589 ; 01694332 (ISSN) Karimzadeh, N ; Moghaddam, E. G ; Mirjani, M ; Raeissi, K ; Sharif University of Technology
    In this research, microstructure and corrosion properties of plasma nitriding and post-oxidation treated AISI 316 austenitic stainless steel have been studied. The plasma nitriding treatment was carried out at 450 C for 5 h in a D.C. plasma setup with a gas mixture of 25% N2-75% H2 followed by post-oxidation in gas mixtures of O2/H2: 1/3, 1/5, 1/9 and 1/12 for 30 min. The treated samples were characterized by SEM, XRD and roughness testing. Potentiodynamic and cyclic polarization tests were also employed to evaluate the corrosion resistance of the samples. The results showed that plasma nitriding treatment decreases corrosion resistance of the steel substrate. However, post-oxidizing... 

    Corrosion Resistance of Steel Reinforcement in Concrete Using Cellulose and Carbon Fiber Materials in Persian Gulf Water

    , M.Sc. Thesis Sharif University of Technology Gharaei, Pedram (Author) ; Zabihollah, Abolghasem (Supervisor) ; Shams, Mohammad Reza (Supervisor)
    Corrosion study of the reinforced concrete is one of the most commonly investigation for the construction in civil engineering. The corrosion of embedded steel for the structures in the marine area like the Persian Gulf Sea Water needed considerable attentions. Presence of chlorides and decrease of pH in pores reinforcement depth of concrete is a serious problem. Research the corrosion rate in reinforced concrete system using fibers with a rebar is investigated. Cellulose and Carbon fiber materials are used as inhibitors. The addition of small quantities of these materials into the concrete mixture, will change the concrete permeability and the corrosion resistance rate. Tests demonstrate... 

    Electrodeposition of Ni-P/Zn-Ni Compositionally Modulated Multilayer Coatings using Single bath Technique

    , Ph.D. Dissertation Sharif University of Technology Bahadormanesh, Behrouz (Author) ; Ghorbani, Mohammad (Supervisor)
    In present study, with the aim of fabrication of a sacrificial coating with superior barrier properties in comparison with Zn-Ni monolayer, a single Zn-Ni-P bath was developed for electrodeposition of Ni-P/Zn-Ni multilayers. The deposits that were prepared in developed bath at 5 mA/cm2 was dominantly Ni-P containing less than 1 percent Zn and the alloy deposited in 60 mA/cm2 was mainly Zn-Ni containing around 3.2 wt.% P content. The effects of bath ingredients on the electrodeposition mechanism was analyzed through voltammetry. Also, the composition, surface morphology and the growth mechanism as well as the phase structure of deposits were studied via SEM, EDS and XRD analysis. Zn-Ni... 

    Effect of Oleuropein as Green Inhibitor on Corrosion Protection of Painted Steel

    , M.Sc. Thesis Sharif University of Technology Pourghazian Esfahani, Alireza (Author) ; Ghorbani, Mohammad (Supervisor)
    The corrosion rate of steel (EN 10130 DC-04) in the presence of oleuropein in aqueous corrosive solutions (of different concentrations in 1M and 0.5M hydrochloric acid and also 3.5% sodium chloride) evaluated and results was shown that oleuropein can protect steel surfaces and it acts as good inhibitor. This means that the observations of linear polarization and weight loss experiments showed inhibitor efficiency more than 97% in acidic corrosive medium and above 74% for aqueous solution of 3.5% sodium chloride. Adding oleuropein at different concentrations (i.e. 300 ppm, 700 ppm, and 1000 ppm) to three different types of polymeric paint structures (nitrocellulose alkyd base, acrylic base,... 

    Evaluation of the Effect of Olive Leaf Extract (Olive Leaf) as a Green Inhibitor on Corrosion of Concrete Steel Reinforcements in the Persian Gulf Sea Water Simulator

    , M.Sc. Thesis Sharif University of Technology Behroozi, Mohammad Hossein (Author) ; Afshar, Abdollah (Supervisor)
    In this project, olive leaf extract has been investigated as a green corrosion inhibitor or in other words environmentally friendly for rebars embedded in concrete in the Persian Gulf Sea water simulator. Olive leaves were prepared by ultrasonic method at 50 ° C with the help of ethanol solvent. The water-ethanol solvent was 70:30 and the resulting extract was immediately applied to the concrete mix in specified doses. Portland cement type 2 according to ISIRI-389-96 standard has been used to prepare concrete. The resulting extract powder was added to the samples in four different doses: 2%, 4%, 6%, 8% by weight of cement to prove the inhibitory function as well as the cathodic or inhibitory... 

    Failure analysis of a gas turbine marriage bolt

    , Article Journal of Failure Analysis and Prevention ; Volume 7, Issue 2 , 2007 , Pages 81-86 ; 15477029 (ISSN) Mohammadi, M ; Salimi, H. R ; Sharif University of Technology
    A gas turbine which output 18MW power exploded after 3h of ordinary operation and after 4,785 starts. The turbine's rotor had undergone repair after 77,000 operating hours. A piece was cut from the failed marriage bolt and tested using atomic absorption spectrometry in order to know the grade of the alloy. It was found that the marriage bolt is made from ASTM A193 B16 steel which is suitable. Hardness and microhardness measurement was also determined and showed that it was within the range of the specified hardness for ASTM A193 B16 steel. The marriage bolt's mechanical properties also meet technical specifications and showed that it contained anti-corrosion properties. Visual examination... 

    Effect of inhibitors on the corrosion of automotive aluminum alloy in ethylene glycol-water mixture

    , Article Corrosion ; Volume 67, Issue 12 , 2011 ; 00109312 (ISSN) Asadikiya, M ; Ghorbani, M ; Sharif University of Technology
    The effect of some inhibitors consisting of sodium nitrite (NaNO 2), sodium nitrate (NaNO 3), sodium molybdate (Na 2MoO 4), and sodium silicate (Na 2SiO 3) on the corrosion behavior of aluminum alloy 3303 (UNS A93303) in a water and ethylene glycol (C 2H 6O 2) mixture was investigated. In the first part, the tests were established without any galvanic coupling. In the second part, the tests were established with galvanic connections between the aluminum alloy and mild steel, stainless steel, copper, brass, and solder. Results show that the best corrosion inhibitor in both situations is sodium nitrate, according to its abilities to reduce corrosion rate, passivate the aluminum surface, and... 

    Effect of post weld heat treatment on mechanical and corrosion behaviors of niTi and stainless steel laser-welded wires

    , Article Journal of Materials Engineering and Performance ; 2016 , Pages 1-8 ; 10599495 (ISSN) Mirshekari, G. R ; Saatchi, A ; Kermanpur, A ; Sadrnezhaad, S. K ; Sharif University of Technology
    Springer New York LLC  2016
    Effects of post weld heat treatment (PWHT) on mechanical properties and corrosion behavior of NiTi shape memory wire, laser welded to the 304 stainless steel wire were investigated. The results showed that PWHT at 200 °C increased corrosion resistance and tensile strength of the joint up to ~1.8 times that of the as-weld joint, with no heat treatment. On the contrary, precipitation of neoteric intermetallic compounds like Fe2Ti, Cr2Ti, FeNi, Ni3Ti, and Ti2Ni in the welded region deteriorated these properties, when PWHT was conducted at 400 °C. Due to the vital effects of the PWHT performed after the laser welding, careful control of the PWHT temperature was found to be a prerequisite for... 

    The investigation of laser shock peening effects on corrosion and hardness properties of ANSI 316L stainless steel

    , Article International Journal of Advanced Manufacturing Technology ; Volume 88, Issue 5-8 , 2017 , Pages 1557-1565 ; 02683768 (ISSN) Ebrahimi, M ; Amini, S ; Mahdavi, S. M ; Sharif University of Technology
    Springer London  2017
    Laser shock peening (LSP) is known as a post processing surface treatment which can improve the mechanical properties of some materials. Shock waves are generated by confining the laser-induced plasma to cause a large pressure shock wave over a significant surface area. In the present study, effects of LSP on the electrochemical corrosion and micro hardness properties of 316L stainless steel alloy were investigated by changing the laser parameters such as the laser spot size, the average number of impacts, and the laser intensity. Since laser parameters do not cover the desired region of LSP, we have to use the proper design of experiment method, in which the D-optimal design of MATLAB was... 

    Corrosion behavior of TLP bonded stainless steel 304 with Ni-based interlayer

    , Article Journal of Manufacturing Processes ; Volume 42 , 2019 , Pages 131-138 ; 15266125 (ISSN) Kazazi, A ; Ekrami, A ; Sharif University of Technology
    Elsevier Ltd  2019
    Transient liquid phase bonding of AISI 304 was carried out in a vacuum furnace using a Ni-based interlayer. The effect of bonding time on microstructure and mechanical properties of joints made at temperature of 1150 ⁰C was investigated. The results showed that isothermal solidification was completed within 20 min and the eutectic phase disappeared across the joint region. The joints with complete isothermal solidification were homogenized for 180 min at a temperature of 950 ⁰C. The shear test results showed that the average shear strength of the homogenized samples was about 83% of that of the base metal at the same heat treatment cycle. Corrosion behavior of the TLP-bonded samples and the... 

    Effect of photoelectrochemical activity of ZnO-graphene thin film on the corrosion of carbon steel and 304 stainless steel

    , Article Journal of Materials Engineering and Performance ; Volume 29, Issue 1 , 2020 , Pages 497-505 Razavizadeh, O ; Bahadormanesh, B ; Ghorbani, M ; Simchi, A ; Sharif University of Technology
    Springer  2020
    In this research, the ZnOG hybrid thin film was produced via solgel method. The surface morphology, band gap and photoactive properties of the films were studied by means of SEM, UV–Vis and photoluminescence analysis. In addition, the ability of the thin film in photocathodic protection of carbon steel (CS) and 304 stainless steel in 3.5 wt.% NaCl and Na2S solutions under dark and UV illumination was investigated by polarization test as well as OCP and current measurements during coupling of steels with ZnOG photoanode. The mix band gap is reduced to the orders of 1.17 eV through hybridization of ZnO with graphene oxide. In both NaCl and Na2S solutions, the ZnOG thin film could effectively... 

    Optimization of nano HA-SiC coating on AISI 316L medical grade stainless steel via electrophoretic deposition

    , Article Materials Letters ; Volume 285 , 2021 ; 0167577X (ISSN) Hosseini, M. R ; Ahangari, M ; Johar, M. H ; Allahkaram, S. R ; Sharif University of Technology
    Elsevier B.V  2021
    Biocompatible nanostructured coating plays an important role in enhancement of osseointegration ability of metallic implants. This study sets out to obtain optimized SiC concentration in Hydroxyapatite (HA) coating on AISI 316L stainless steel alloy through electrophoretic deposition method. Effect of SiC concentrations (1, 2, and 3%.wt) on the morphology, corrosion behaviour, and mechanical properties of the HA coating is investigated. Results show that SiC could obstruct the formation and growth of micro cracks in the HA coating where HA-3%SiC is considered as a crack free coating. Electrochemical tests reveal that SiC has improved the corrosion resistance of HA coating, and HA-3%SiC... 

    Active Corrosion Protection Application of Conducting Polymer Coating on Steel

    , M.Sc. Thesis Sharif University of Technology Naghavi, Samira (Author) ; Ghorbani, Habib (Supervisor)
    Corrosion is caused through chemical interactions between metal and gases in the surrounding environment. Conductive polymers are used for corrosion protection, polyaniline is the most environmentally stable out of all the conductive polymers, the most studied of this materials, is highly stable, synthesized easily, highly conducting, and readily converted between its various oxidation states.
    In this study we prepared nanoporous polyaniline coating on carbon steel to corrosion protection. Coating was included nanopouros polyaniline with doping molybdate (PANI-MoO_4^(-2)). To increase adhesion between steel and PANI-MoO_4^(-2) layer, oxalic acid was used. Polystyrene nanoparticle layer... 

    A Study on the Impact of Extract of Green Coffee Beans as a Green Corrosion Inhibitor of Mild Steel in Simulated Concrete Pore Solution

    , M.Sc. Thesis Sharif University of Technology Khalili Azar, Mojtaba (Author) ; Afshar, Abdollah (Supervisor)
    In this study, the effect of green coffee extract powder, as a green corrosion inhibitor of steel in a concrete simulation environment was investigated. In this study, the green coffee extract was obtained by the Maceration method and its performance was investigated by weight loss method, electrochemical methods including Polarization, Electrochemical Impedance Spectroscopy. Scanning Electron Microscopy images were also used to visualize the corroded areas. The results of the polarization test showed that 450 mg/lit of coffee extract powder at 25 °C has the corrosion inhibiting efficiency of about 82% and the corrosion rate of the bare sample reduced from 6 to 1.16 mpy. The dosage of 550... 

    Deposition and Properties of ZIF-8/SiO2 Hydrophobi Anti-Corrosion Coating

    , M.Sc. Thesis Sharif University of Technology Tajaslan, Parisa (Author) ; Dolati, Abolghasem (Supervisor)
    In this research, a coating was created on the steel surface using the network structure of zeolite imidazolate-8 (ZIF-8) and its effect on the corrosion behavior of steel was investigated. Then, the effect of two coupling agents, mercaptopropyltriethoxysilane (MPTES) and aminopropyltriethoxysilane (APTES) on the coating and its anti-corrosion properties was investigated. Then, in order to make a hydrophobic coating, the substrate was first coated with ZIF-8 and then a combination of silica nanoparticles plus hexamethyldisilazane (HMDS) and polymethylhydrogensiloxane (PMHS) was added to the initial solution and then coating was done. As a result of this process, the contact angle of water... 

    Titania nanostructured coating for corrosion mitigation of stainless steel

    , Article Protection of Metals and Physical Chemistry of Surfaces ; Vol. 50, issue. 3 , 2014 , p. 371-377 Barati, N ; Sani, M. A. F ; Sadeghian, Z ; Ghasemi, H ; Sharif University of Technology
    Anatase nanostructured coating has been prepared on 316 L stainless steel by sol-gel dip coating. The topography of the coatings surface has been analyzed using atomic force microscopy. The anticorrosion performance of the coatings has been evaluated using polarization curves. Effects of calcination temperature, withdrawal speed and times of coating on corrosion protection have been studied. The results showed calcination temperature of 400°C and withdrawal speed of 10 cm/min are desirable conditions to achieve high corrosion protection of 316 L stainless steel in chloride containing environments. Coatings with 3 times exhibit better resistance against corrosion in 0.5 molar NaCl solutions.... 

    The corrosion investigation of rebar embedded in the fibers reinforced concrete

    , Article Construction and Building Materials ; Volume 35 , October , 2012 , Pages 564-570 ; 09500618 (ISSN) Kakooei, S ; Akil, H. M ; Dolati, A ; Rouhi, J ; Sharif University of Technology
    Elsevier  2012
    One effective method for preventing corrosion of steel reinforcement and improving the mechanical properties of concrete is changing the physical nature of concrete by adding different materials. In this study, we have used polypropylene fibers as an additional material. We have compared the corrosion rate of rebar using different volume ratios and sizes of polypropylene fibers. Reinforcement potential increased as the amount of fibers increased from 0 to 2 kg m -3. The polypropylene fibers delay the initial corrosion process by preventing cracking, thereby decreasing permeability of the concrete. In addition, the corrosion rate of concrete samples made with Kish Island coral aggregate was... 

    An electrochemical synthesis of reduced graphene oxide/zinc nanocomposite coating through pulse-potential electrodeposition technique and the consequent corrosion resistance

    , Article International Journal of Corrosion ; Volume 2018 , 2018 ; 16879325 (ISSN) Moshgi Asl, S ; Afshar, A ; Yaghoubinezhad, Y ; Sharif University of Technology
    Hindawi Limited  2018
    Pulse-potential coelectrodeposition of reduced graphene oxide/zinc (rGO-Zn) nanocomposite coating is directly controlled upon a steel substrate from a one-pot aqueous mixture containing [GO-/Zn2+]δ+ nanoclusters. GO nanosheets are synthesized by modified Hummer's approach while Zn cations are produced in the solution and deposited on GO nanosheets using anodic dissolution technique. Eventually, nanoclusters are reduced to rGO-Zn film through an electrochemical process. Chemical composition, surface morphology, and corrosion resistance of the thin film are characterized. Results show that the corrosion resistance of rGO-Zn coating is approximately 10 times more than the bare steel. © 2018 S.... 

    Fatigue limit prediction and analysis of nano-structured AISI 304 steel by severe shot peening via ANN

    , Article Engineering with Computers ; February , 2020 Maleki, E ; Unal, O ; Sharif University of Technology
    Springer  2020
    AISI 304 stainless steel is very widely used for industrial applications due to its good integrated performance and corrosion resistance. However, shot peening (SP) is known as one of the effectual surface treatments processes to provide superior properties in metallic materials. In the present study, a comprehensive study on SP of AISI 304 steel including 42 different SP treatments with a wide range of Almen intensities of 14–36 A and various coverage of 100–2000% was carried out. Varieties of experiments were accomplished for the investigation of the microstructure, grain size, surface topography, hardness and residual stresses as well as axial fatigue behavior. After experimental...