Influence of Pyrrhotite on the Corrosion of Mild Steel

CORROSION ◽  
10.5006/2505 ◽  
2017 ◽  
Vol 74 (1) ◽  
pp. 37-49 ◽  
Author(s):  
Saba Navabzadeh Esmaeely ◽  
Gheorghe Bota ◽  
Bruce Brown ◽  
Srdjan Nešić
Keyword(s):  
Mild Steel ◽  
Steel Surface ◽  
Product Layer ◽  
Localized Corrosion ◽  
X Ray Diffraction ◽  
Galvanic Coupling ◽  
X Ray ◽  
H2s Corrosion ◽  
Corrosion Product Layer ◽  
Nacl Concentration

As a result of the electrical conductivity of pyrrhotite, it was hypothesized that its presence in the corrosion product layer on a steel surface could lead to localized corrosion. Mild steel specimens (API 5L X65) were pretreated to form a pyrrhotite layer on the surface using high-temperature sulfidation in oil. The pretreated specimens were then exposed to a range of aqueous CO2 and H2S corrosion environments at 30°C and 60°C. X-ray diffraction data showed that the pyrrhotite layer changed during exposure; in an aqueous CO2 solution it underwent dissolution, while in a mixed CO2/H2S solution it partially transformed to troilite, with some mackinawite formation. Initiation of localized corrosion was observed in both cases. It was concluded that this was the result of a galvanic coupling between the pyrrhotite layer and the steel surface. The intensity of the observed localized corrosion varied with solution conductivity (NaCl concentration); a more conductive solution resulted in higher localized corrosion rates, consistent with the galvanic nature of the attack.

Chromium Alloyed Steel Nitriding within Close-To-Critical Temperature Range

2014 ◽  
Vol 1013 ◽  
pp. 146-152 ◽  
Author(s):  
Zhanna G. Kovalevskaya ◽  
Vasilii A. Klimenov ◽  
I.M. Goncharenko ◽  
Yurii F. Ivanov ◽  
N.S. Belousova
Keyword(s):  
Critical Temperature ◽  
Mild Steel ◽  
Steel Surface ◽  
Arc Discharge ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Range ◽  
Pre Treatment ◽  
Nitride Layers ◽  
Scanning Electron

The paper presents X-ray diffraction and scanning electron microscope analyses, and durometer measurements used to investigate the structural properties and phase composition of nitride layers of type 20Kh13 mild steel. A method of nitriding by low-pressure arc discharge was applied along with the combined surface treatment including ultrasonic finishing and nitriding. It was shown that within the close-to-critical temperature range starting from 200oС, the nitride layers was formed on the surface of type 20Kh13 mild steel. The ultrasonic pre-treatment shown its effect on the steel nitriding that increased the amount of nitride phases and the value of microharness on the steel surface.

scholarly journals Corrosion of Copper in Unpolluted Chloride-Rich Atmospheres

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 866 ◽  
Author(s):  
Patricia Lopesino ◽  
Jenifer Alcántara ◽  
Daniel de la Fuente ◽  
Belén Chico ◽  
José Jiménez ◽  
...  
Keyword(s):  
Atmospheric Corrosion ◽  
Product Layer ◽  
Corrosion Products ◽  
X Ray Diffraction ◽  
Deposition Rates ◽  
X Ray ◽  
Corrosion Product Layer ◽  
Salinity Levels ◽  
Notable Increase ◽  
Chloride Deposition

The atmospheric corrosion of copper in pure coastal atmospheres has not been extensively studied. This paper presents the results of research carried out in pure coastal atmospheres with annual chloride deposition rates of between 110–1640 mg/m2·d. Copper specimens (99.99 wt % Cu) were exposed for 3, 6, 9, and 12 months at six testing stations located at different distances from the seashore. Tests were performed to determine the copper corrosion rate, the surface area coated with corrosion products, and the evolution of both magnitudes with exposure time. Conventional and grazing X-ray diffraction techniques were used to analyze the corrosion products formed—cuprite and the polymorphs botallackite, atacamite, and clinoatacamite—and their presence through the patina thickness, while scanning electron microscopy/energy dispersive X-ray spectrometry was employed to study the morphology of the resulting corrosion layers. The most relevant findings are a notable increase in atacamite and clinoatacamite formation at higher atmospheric salinity levels and longer exposure times, and the flaking-off of the corrosion product layer formed in the marine atmospheres with the highest chloride deposition rates.

scholarly journals Corrosion Inhibition of Mild Steel by Poly(butylene succinate)-L-histidine Extended with 1,6-diisocynatohexane Polymer Composite in 1 M HCl

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
M. G. Tsoeunyane ◽  
M. E. Makhatha ◽  
O. A. Arotiba
Keyword(s):  
Mild Steel ◽  
Corrosion Inhibition ◽  
Polymer Composite ◽  
Electrochemical Impedance ◽  
Condensation Polymerization ◽  
X Ray Diffraction ◽  
Butylene Succinate ◽  
X Ray ◽  
Atomic Force ◽  
Corrosion Inhibition Efficiency

The ecofriendly poly(butylene succinate) extended with 1,6-diisocynatohexane composted with L-histidine (PBSLH) polymer composite was synthesized by condensation polymerization. The polymer composite was characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), and scanning electron microscope (SEM-EDX). The inhibition action of the polymer composite was investigated by conventional weight loss, potentiodynamic polarization, variable amplitude micro (VASP), and electrochemical impedance spectroscopy (EIS). The maximum corrosion inhibition efficiency of 78 % was obtained at concentration level of 600 ppm. The results revealed PBSLH as a mixed type corrosion inhibitor. The thermodynamic and kinetic parameters also revealed adsorption of PBSLH on to mild surface as exothermic and the adsorption was conformed to Langmuir model. The morphology of mild steel coupons was investigated by SEM and atomic force microscope (AFM) and the results showed PBSLH to have inhibited corrosion on mild steel in 1 M HCL.

Corrosion protection performance of titania nanoparticles filled poly(4-methyl-5-vinylthiazole) applied on mild steel in 3.5% sodium chloride solution

2020 ◽  
pp. 875608792093930 ◽  
Author(s):  
I Pugazhenthi ◽  
S Mohammed Ghouse
Keyword(s):  
Mild Steel ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Nano Particles ◽  
Titania Nanoparticles ◽  
X Ray Diffraction ◽  
Corrosive Media ◽  
X Ray ◽  
Polymer Hybrid ◽  
Transmission Electron

Mild steel materials have wide applications in marine construction, because they are low cost, available and easy to handle. However, they have to be protected from corrosive media by coating with polymer hybrid materials. This paper focuses on the anticorrosive properties of poly(4-methyl-5-vinylthiazole) PVTZ coatings on mild steel. Further the coating resistance is enhanced by incorporating Titania Nano particles (TiO2NPs). The nanoparticles were evaluated using X-ray diffraction studies (XRD) and transmission electron microscopy (TEM). PVTZ and its TiO2 nanocomposite were coated on mild steel. Their anticorrosive behavior was analyzed by potentiodynamic polarization and electrochemical impedance spectroscopy in 3.5% (w/v) NaCl.

Microstructure and Property of Wear-Resistant Coating Layer by High-Frequency Induction Cladding on Mild Steel Surface

2011 ◽  
Vol 239-242 ◽  
pp. 773-776
Author(s):  
Li Yang ◽  
Gang Li
Keyword(s):  
Wear Resistance ◽  
Mild Steel ◽  
High Frequency ◽  
Coating Layer ◽  
High Hardness ◽  
Alloy Coating ◽  
Alloy Layer ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Frequency Induction

In order to improve the wear resistance of mild steel products, the Fe-based alloy layer was melted on the surface of mild steel by high-frequency induction cladding. Using scanning electron microscopy, energy dispersive spectroscopy and x-ray diffraction observation of microstructure of the alloy coating, wear resistance of the coating was evaluated. The results showed that: between the coating and the substrate is metallurgical bonded; The microstructure of coating layer was compact actinomorphous structure with plentiful nubby and strip eutectics; Actinomorphous structure was mixed structure of martensite and γ alloy solid solution covered with a large number floriform and dendrite eutectic; The coating has high hardness and good wear resistance.

Effect of Microstructure on the Corrosion Behavior of TiN Coatings

2011 ◽  
Vol 415-417 ◽  
pp. 1911-1916
Author(s):  
Marwan Azzi ◽  
Jolanta Eva Klemberg Sapieha
Keyword(s):  
Columnar Structure ◽  
Hard Coatings ◽  
Localized Corrosion ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
X Ray ◽  
Tin Coatings ◽  
Tin Film ◽  
Electrolyte Interface ◽  
Homogeneous Film

In this paper, the corrosion properties of AISI 301 stainless steel (SS) coated with 1-micron thick titanium nitride (TiN) hard coatings is investigated. TiN was deposited by pulsed magnetron sputtering resulting in different microstructure ranging from agglomerated crystallites to homogeneous film. Microstructure of the coatings was characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD), and energy dispersive spectroscopy (EDS). Resistance to general and localized corrosion was evaluated by potentiodynamic polarization in NaCl 1% solution. It has been shown that the existence of columnar structure in the TiN film reduces significantly the resistance to localized corrosion due to infiltration of liquid through paths at the grain boundaries. Furthermore, by comparing the polarization curves of TiN coatings deposited on SS and glass, it was shown that the electrochemical response of TiN-coated SS at low potentials is the result of electrochemical activity at the coating/electrolyte interface whereas at high potentials the increase in the current is the result of pits generated at the substrate/electrolyte interface at defects/pores within the coating.

scholarly journals Corrosion Behaviour of Zn-10Al-1.5Cu Alloy

2011 ◽  
Vol 2011 ◽  
pp. 1-6
Author(s):  
C. N. Panagopoulos ◽  
A. G. Tsopani
Keyword(s):  
Electron Microscopy ◽  
Corrosion Resistance ◽  
Corrosion Behaviour ◽  
Solution Concentration ◽  
Solution Temperature ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nacl Concentration ◽  
Scanning Electron

The corrosion behaviour of Zn-10Al-1.5Cu alloy in NaCl solution was examined. The used NaCl solution concentrations were 1M, 0.3M, and 0.003M for a constant temperature values of 7°C or 25°C or 45°C. The corrosion behaviour of this alloy was investigated under potentiodynamic corrosion conditions. The surface of the corroded alloy specimens was studied with the aid of scanning electron microscopy and X-ray diffraction techniques. It was observed that the increase of NaCl concentration in the corrosion solution for a constant value of temperature led to lower corrosion resistance of the alloy. For a constant value of solution concentration, the increase of solution temperature also led to the decrease of corrosion resistance of the same alloy.

scholarly journals A new attack upon the problem of fatigue of metals, using X-ray methods of precision

1936 ◽  
Vol 154 (883) ◽  
pp. 510-539 ◽  
Keyword(s):  
Tensile Stress ◽  
Mild Steel ◽  
Yield Point ◽  
Systematic Study ◽  
Fatigue Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
Static Tensile ◽  
Static Yield ◽  
Ray Methods

The failure of metals by fatigue has been investigated by applying precise methods of X-ray diffraction to a systematic study of the changes produced in the crystalline structure under various conditions of test. The material used for the experiments was a normalized mild steel (0*1% C). The fatigue tests were of three distinct types involving, respectively, ( a ) cycles of reversed torsional stressed, ( b ) cycles of reversed direct stresses, and ( c ) cycles of alternating direct stresses where the superior stress of the cycle was maintained at a constant value of tensile stress exceeding the static yield point of the material. In addition, comparable observations have been made of the changes in structure arising from the application of static tensile and static torsional stresses of various intensities including those causing fracture.

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