Synergistic effect of chloride and NO2 on the atmospheric corrosion of bronze

2009 ◽  
Vol 56 (6) ◽  
pp. 299-305 ◽  
Author(s):  
Xia Cao ◽  
Ning Wang ◽  
Ning Liu
Keyword(s):  
Synergistic Effect ◽  
Design Methodology ◽  
Atmospheric Corrosion ◽  
Electrochemical Impedance ◽  
X Ray Diffraction ◽  
Impedance Measurements ◽  
Content Type ◽  
X Ray ◽  
Corrosion Kinetics ◽  
Tension Tests

PurposeThe purpose of this paper is to investigate the effect of chloride along with NO2 on the atmospheric corrosion of bronze using exposure tests.Design/methodology/approachSurface tension tests and electrochemical impedance measurements together with scanning electron microscopy (SEM) with energy dispersive atomic X‐ray, and X‐ray diffraction are used to characterize the corrosion behavior.FindingsThe results of the weight loss measurements show that the whole corrosion kinetics can be described approximately by: ΔW=atb; the synergistic effect of chloride and NO2 is observed clearly, though no nitrate existed in the corrosion products.Originality/valueA new catalyst theory has been suggested in this paper, i.e. that NO2 acts as a catalyst during the corrosion process when significant quantities of chloride also are present.

Structural, electrochemical and mechanical studies of ultrasonic irradiation enhanced electroplating Ni coating

2018 ◽  
Vol 65 (4) ◽  
pp. 333-339 ◽  
Author(s):  
Chaolei Ban ◽  
Shuqin Zhu ◽  
Jie Ma ◽  
Fangreng Wang ◽  
Zhengfeng Jia ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Ultrasonic Irradiation ◽  
Design Methodology ◽  
Electrochemical Impedance ◽  
Steel Substrate ◽  
X Ray Diffraction ◽  
Content Type ◽  
X Ray ◽  
Mechanical Studies

Purpose Ni coating was electroplated on carbon steel substrate to protect carbon steel. Design/methodology/approach During electroplating, the ultrasonic irradiation (UI) (1 kHz) action was in situ used with different frequency. The influence of UI on the microstructure, mechanical and electrochemical performance of the coating was studied with scanning electron microscopy, X-ray diffraction, microhardness measurement, polarization curves and electrochemical impedance spectroscopy. Findings The results show that comparing that without UI imposition, UI during electroplating can refine the coating grain and decrease the micro-pores in the coating, resulting in improvement of the coating corrosion and hardness. Originality/value The imposition of UI action during electroplating Ni coating can remove intrinsic pores in the coating and compact the coating. The potential bimetallic cell between substrate and plating layer can be insulated to enhance the corrosion resistance of Ni coating. The imposition of UI action during electroplating Ni coating can refine Ni coating grain size and improve the coating haredness.

The influence of hexamethylenetetramine on the structure and corrosion resistance of phosphate coating on AZ31 magnesium alloy

2016 ◽  
Vol 63 (3) ◽  
pp. 161-165 ◽  
Author(s):  
Jiansan Li ◽  
Yali Li ◽  
Yanqin Chen ◽  
Jiawei Sun ◽  
Chunxiao Wang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloys ◽  
Design Methodology ◽  
Energy Dispersive Spectrometry ◽  
Electrochemical Impedance ◽  
Phosphate Coating ◽  
X Ray Diffraction ◽  
Content Type ◽  
X Ray ◽  
Phosphate Coatings

Purpose This paper aims to report the influence of hexamethylenetetramine (HMTA) on phosphate coatings formed on AZ31 magnesium alloys. Design/methodology/approach These phosphate coatings were obtained by immersing magnesium alloys in phosphate baths with HMTA. The morphology and composition of the phosphate coatings were investigated via scanning electron microscopy, energy dispersive spectrometry and X-ray diffraction. Findings The phosphate coatings were mainly composed of CaHPO4·2H2O. The HMTA concentration in the phosphate bath influenced the crystallization and corrosion resistance of the phosphate coating. Originality/value The polarization curve shows that the anti-corrosion qualities of the phosphate coating were optimal when the HMTA concentration was 1.0 g/L in the phosphate bath. Electrochemical impedance spectroscopy (EIS) shows that the electrochemical impedances increased gradually when the HMTA concentration varied from 1.0 to 3.0 g/L.

Dependence of hydrogen embrittlement on annealing time in medium-Mn steels

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Juanping Xu ◽  
Jinxu Li ◽  
Zheng Wang ◽  
Hao Fu ◽  
Ming Wu
Keyword(s):  
Hydrogen Embrittlement ◽  
Annealing Time ◽  
Martensite Transformation ◽  
Design Methodology ◽  
Warm Rolling ◽  
X Ray Diffraction ◽  
Electron Backscattered Diffraction ◽  
Content Type ◽  
X Ray ◽  
Two Samples

Purpose The purpose of this paper is to investigate the effect of the soft annealing time on the microstructure and hydrogen embrittlement (HE) of Fe-0.22C-11.54Mn-2.05Al steels. Design/methodology/approach Steels A and B with different morphologies were prepared by cold rolling after warm rolling, long/short softening annealing and finally annealing at 700 °C for 30 min. Uncharged and charged samples were subjected to tensile, and HE behavior was studied by electron backscattered diffraction, scanning electron microscopy and X-ray diffraction. Findings The two samples exhibited similar tensile strengths. The homogeneous equiaxed microstructure of steel B was found to be more conducive to relieve its HE sensitivity. Steel A exhibited bimodal-grained microstructures – blocky and lath. The formation of crack in the blocky grains of steel A resulted in a significant reduction in its plasticity and tensile strength. Originality/value The high HE susceptibility of steel A is mainly connected with the inhomogeneity of martensite transformation.

Corrosion inhibition of N80 steel in 10% HCl + 8% HBF4solution

2019 ◽  
Vol 66 (1) ◽  
pp. 1-10
Author(s):  
Juan Du ◽  
Yuning He ◽  
Pingli Liu ◽  
Yigang Liu ◽  
Xianghai Meng ◽  
...  
Keyword(s):  
Corrosion Inhibition ◽  
Design Methodology ◽  
X Ray Diffraction ◽  
Corrosion Morphology ◽  
Content Type ◽  
X Ray ◽  
N80 Steel ◽  
Corrosion Reaction ◽  
Hydrolysis Of ◽  
Scanning Electron

PurposeThis paper aims to analyze the corrosion and corrosion inhibition of N80 in 10 per cent HCl + 8 per cent fluoroboric acid (HBF4) solution for acidizing operation.Design/methodology/approachThe corrosion rate, kinetic parameters (Ea, A) and thermodynamic parameters (ΔH, ΔS) of N80 steel in fresh acid and spent acid, 10 per cent HCl + 8 per cent HBF4, 10 per cent HCl and 8 per cent HBF4solutions were calculated through immersion tests. The corrosion and inhibition properties were studied through X-ray diffraction and electrochemical measurements. The corrosion morphology of the corrosion product was examined by scanning electron microscopy (SEM).FindingsThe results demonstrated that the spent acid was the main cause of acidification corrosion, and the HBF4would cause serious corrosion to N80 steel. The results showed that the N80 steel was more seriously corroded in the spent acid than in fresh acid, and the hydrolysis of HBF4accelerates the dissolution process of N80 steel anode to control the corrosion reaction. The results showed that the acidification will definitely cause serious corrosion to the oil tube; therefore, necessary anti-corrosion measures must be taken in the acidification process.Originality/valueThe results showed that acidizing the formation with 10 per cent HCl + 8 per cent HBF4will definitely cause serious corrosion to the oil tube, especially when the spent acid flows back. Therefore, necessary anti-corrosion measures must be taken in the acidification process, especially in the spent acid flowback stage.

Influence of sour oil on calcareous deposit nucleation

2017 ◽  
Vol 64 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Morteza Hoseinieh ◽  
Taghi Shahrabi ◽  
Morteza Farrokhi Rad ◽  
Bahram Ramezanzadeh
Keyword(s):  
Electrochemical Impedance ◽  
Physical Adsorption ◽  
Inhibition Mechanism ◽  
X Ray Diffraction ◽  
Steel Electrode ◽  
Content Type ◽  
X Ray ◽  
Sour Crude ◽  
Corrosion Mechanisms ◽  
Scale Deposition

Purpose The aim of this paper is to investigate the influence of sour crude oil contaminant on the calcareous scale deposition under cathodic protection of carbon steel in artificial seawater. Design/methodology/approach Electrochemical and surface characterizations are carried out using chronoamperometry, electrochemical impedance spectroscopy, scanning electron microscope/energy dispersive spectroscopy, X-Ray diffraction and Raman spectroscopy techniques. Findings Results showed that sour oil limited the deposit nucleation regarding its volume concentrations. The inhibition mechanism was examined to be simultaneous acts of pH reduction and mackinawite formation beside minor physical adsorption of oil molecules on steel electrode. Originality/value There is no paper concerning the proposed subject, and the idea of this work is fully novel which is of great significance because of the consequences of disastrous oil spill phenomena on the integrity of exposed offshore facilities in terms of optimum protection against probable corrosion mechanisms.

The preparation and properties of multifunctional coating of aluminum alloy for medical external application

2015 ◽  
Vol 6 (3) ◽  
pp. 326-337
Author(s):  
Shu-Hao Deng ◽  
Xi Yang ◽  
Mao Wang ◽  
Jiao Wang
Keyword(s):  
Design Methodology ◽  
External Surface ◽  
Al Alloy ◽  
X Ray Diffraction ◽  
External Application ◽  
Content Type ◽  
X Ray ◽  
Photochemical Decomposition ◽  
Self Cleaning ◽  
Better Than

Purpose – The purpose of this paper is to improve anti-corrosion, self-cleaning, hydrophily and sterilization properties of aluminum (Al) alloy. Design/methodology/approach – A multifunctional coating for medical external application on Al alloy had been prepared by anodic oxidation, electrolytic coloring silver (Ag) and sealed in boiling water with nano-sized titanium dioxide (TiO2) particles. The multifunctional coating was characterized by X-ray diffraction, scanning electron microscope and energy dispersive spectroscopy. Other properties such as corrosion-resistance, wipe-resistance, hydrophilicity, photochemical decomposition and bactericidal antiseptic effect were also investigated. Findings – The results demonstrate that a golden film with multi-function had been obtained for medical external application. The main phase of coating is amorphous Al2O3, and nano-sized silver particle is electrodeposited in bottom of film hole, while nano-sized TiO2 is sealed on the external surface of coating. The properties of film, such as anti-corrosion, self-cleaning, hydrophily, sterilization are better than those of Al alloy substrate. Originality/value – Considering about this usage for medical external application, a multifunctional coating which has the properties such as decoration, anti-corrosion, sterilize and self-cleaning has been first prepared on Al alloy surface in the study. This coating would meet the requirements of medical external using and provide theoretical and practical foundation about Al alloy for medical use.

One pot and large-scale synthesis of nanostructured metal sulfides: Synergistic effect on supercapacitor performance

2020 ◽  
Vol 31 (8) ◽  
pp. 1367-1384 ◽  
Author(s):  
C Karthikeyan ◽  
R Dhilip Kumar ◽  
J Anandha Raj ◽  
S Karuppuchamy
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Synergistic Effect ◽  
Large Scale ◽  
Electrochemical Impedance ◽  
Metal Sulfides ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Metal sulfides received key interest as an electrode material for storage and conversion of energy. Here, the novel nanostructured N17S18 and (CoNi)3S4 materials were synthesized via one-step hydrothermal method, and the synergistic effect of metal ions and electrochemical properties was investigated. A new and simple solution growth technique was employed in this work. The prepared nanopowders were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy techniques. The X-ray diffraction analysis of the prepared nanopowder revealed the formation of cubic phase cobalt nickel sulfides (CoNi)3S4 and hexagonal phase nickel sulfides (Ni17S18). Scanning electron microscopy analysis display fibrous, flakes and sheet-like morphology for CoxSx, N17S18 and (CoNi)3S4, respectively. Fibrous and sheet-like morphology exhibits higher electrochemical performance in supercapacitors. The electrochemical behavior of the amorphous CoxSx, crystallite Ni17S18 and (CoNi)3S4 modified electrodes was investigated using electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic charge–discharge techniques. The specific capacitance of 57 F/g and 31 F/g were obtained for the amorphous CoxSx and crystalline (CoNi)3S4 powder, respectively. Amorphous CoxSx modified electrode retains 76% of initial capacitance after 1000 repeated cycling process. These results of this study suggest that the CoxSx and crystalline (CoNi)3S4 are appropriate materials for supercapacitor applications.

Characterization of pharaonic cartonnage from a late period, Saqqara excavations

2020 ◽  
Vol 49 (4) ◽  
pp. 255-264
Author(s):  
Hala A.M. Afifi ◽  
Heba Sayed Galal ◽  
Rushdya Rabee Ali Hassan
Keyword(s):  
Electron Microscopy ◽  
Design Methodology ◽  
X Rays ◽  
Ftir Analysis ◽  
Late Period ◽  
X Ray Diffraction ◽  
Content Type ◽  
X Ray ◽  
Ancient Egyptian

Purpose The purpose of this paper is to identify the pigments, mediums and ground layer used during the late era of ancient Egyptian civilization through the analysis of mummy Cartonnage based on the use of multiple analysis, such as electron microscopy, X-rays, scanning electron microscopy (SEM) and Fourier transform infrared (FTIR). Design/methodology/approach This study analyzed some fragments from a painted cartonnage of a mummy date back to the late period. Light microscopy, X-ray diffraction analysis, FTIR analysis and investigation of the surface morphology by SEM were used to identify the chemical and anatomical structure of cartonnage. Findings The results clearly showed use of copper and extracted gold from the veins of the quartz to get the golden pigment, but it is full of voids which were a major cause of the degradation. Originality/value The study is the first of its kind on the components of this cartonnage in Saqqara stores.

Carburization behavior of high velocity oxy fuel sprayed metallic coatings at 900°C

2014 ◽  
Vol 61 (6) ◽  
pp. 436-444 ◽  
Author(s):  
Abdul Quddus ◽  
Anwar Ul-Hamid ◽  
Huseyin Saricimen
Keyword(s):  
High Velocity ◽  
Petrochemical Industry ◽  
Design Methodology ◽  
Protective Layer ◽  
High Temperature Corrosion ◽  
Metallic Coatings ◽  
X Ray Diffraction ◽  
Corrosion Resistant ◽  
Content Type ◽  
X Ray

Purpose – The purpose of this investigation was to evaluate the performance of high velocity oxy fuel (HVOF) coated SS-310 samples in a carburizing environment. Design/methodology/approach – The carburization behavior of metallic coatings with three different compositions was studied under isothermal carburizing exposure conditions at 900°C for 125 hours. The coatings were deposited on SS 310 substrates using the HVOF technique. The ASTM Standard method was used to evaluate coating adhesion. Scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, X-ray diffraction and weight gain were used to evaluate the surface morphology, microchemical composition, phase constitution and degree of environmental protection imparted by the coatings. Findings – The experimental results indicate that Ni-rich coating offered better protection to SS 310 alloy compared to Co-rich coatings in carburizing environments. This was thought to be due to the formation of a continuous protective layer of Cr2O3 on the Ni-rich coating surface. Originality/value – The study has direct practical relevance to the petrochemical industry, particularly for refinery applications. In refinery service, SS310 is used in header damper plates. The useful service life of such header plates can be extended by the use of high temperature corrosion resistant metallic coatings. The present investigation highlighted the protection offered by Ni-based HVOF coated SS-310 samples in carburizing environment.

Corrosion investigation and evaluation of mechanical and structural properties of powder coatings

2016 ◽  
Vol 7 (1) ◽  
pp. 2-24 ◽  
Author(s):  
Elias P. Koumoulos ◽  
Ioannis A Kartsonakis ◽  
G Vlachakis ◽  
M Vlachakis ◽  
Costas A. Charitidis
Keyword(s):  
Aluminium Alloy ◽  
Design Methodology ◽  
Electrochemical Impedance ◽  
Spray Coating ◽  
Powder Coatings ◽  
Properties Of Coatings ◽  
Content Type ◽  
X Ray ◽  
Nanomechanical Properties ◽  
Corrosion Investigation

Purpose – The purpose of this paper is to deal with the study of properties of anticorrosion powder based coatings on aluminium alloy 2024. Design/methodology/approach – The powder based coatings were applied to the AA2024 substrates using a spray coating technique. All the substrates were covered with a primer prior the powder based coatings. The morphology and composition of the coatings was examined by scanning electron microscopy and energy dispersive X-ray analysis, respectively. Studies on the corrosion resistance of these coatings were made using electrochemical impedance spectroscopy. Findings – The results reveal that the powder based coatings together with the primer coatings demonstrate improved corrosion protection to AA2024 after exposure to corrosive environment. Moreover, the primer coating is mechanically enhanced compared to the top coating, while the top coating exhibited significant resistance to wear. Originality/value – The paper deals with the evaluation of corrosion and nanomechanical properties of coatings applied on aluminium alloy.

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