47 research outputs found
Electrochemical Characterization of the Corrosion of Mild Steel in Saline Following Mechanical Deformation
No full textUpgrading the corrosion properties of metallic materials has been the dream of many corrosion experts and material scientists. The present study investigated the influence of mechanical deformation by rolling process on the corrosion behavior of mild steel through an electrochemical process in a chloride-containing environment at room temperature. The microstructures before and after rolling and corrosion tests were analyzed by scanning electron microscopy (SEM). The mild steels were first subjected to cold rolling with approximately 30% rolling reduction, and the corrosion resistance of both the unrolled and rolled samples was then determined. The polarization results revealed that the rolled mild steel sample possessed a corrosion potential of −0.118 V, reduced corrosion current density of 0.133 mA/cm2, higher impedance, and phase angle maximum. The grain refinement and the surface roughness are related to the deformation and corrosion mechanisms
Passivation Behaviour of Surface-Treated 17-4PH Stainless Steel in Chloride-Containing Environment with Varying Concentrations
No full textThe influence of chloride concentration on the corrosion behaviour of SS17-4PH after surface treatment by mechanical deformation was investigated in 0.6–1 M concentration of NaCl aqueous solution through polarization study and morphology observation. The potentiodynamic polarization results revealed that the corrosion resistance of SS17-4PH decreases with increasing NaCl concentration. Unlike the SS17-4PH samples polarized in a higher concentration of NaCl (0.7 and 0.9 M concentration of NaCl) with higher corrosion current densities (1.486 and 3.085 mA/cm2, respectively), the sample polarized in 0.6 M NaCl exhibited a much lower corrosion current density of 0.807 mA/cm2. The lower corrosion current density value obtained signifes a better corrosion resistance and this can be accrued to the fact that increasing molarity of NaCl solution can increase the electron mobility and conductivity of solution thereby increasing the concentration of ions in the water and thus increases the corrosion rate (rate of oxidation)
Datasets on the corrosion behaviour ofnanostructured AISI 316 stainless steel treatedby SMAT
Get PDFThe present paper contains the experimental datasets on the corrosion behaviour of nanostructured AISI 316 stainless steel (SS) through polarization tests in 0.6 M NaCl aqueous solution at room temperature. The nanostructured layers were first obtained through surface mechanical attrition treatment (SMAT) method and the data information on the corrosion behaviour of the nanostructured layer was thereafter collected. Through potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) studies, the experimental datasets were obtained to investigate the combined effects of SMAT and low temperature annealing on the corrosion behaviour of 316 SS. The experimental datasets obtained include the open circuit potential (OCP), corrosion current densities, corrosion potential, Nyquist, impedance and phase angle. The datasets provided in this article will be of great help to most aerospace, automobile, and manufacturing industries in determining the actual and practical corrosion behaviour of AISI 316 SS in corrosive and aggressive environment
Influence of multilayered polymer coatings on the corrosion behaviour and microstructures of Al6061-T6 alloy
Get PDFThe influence of multilayered polymer coatings on the corrosion and microstructural properties of Al6061-T6 alloy was investigated. The electrochemical properties were determined in chloride solution via corrosion tests and electrochemical impedance spectroscopy (EIS) technique at room temperature. The microstructural properties and corrosion mechanism after polarization were studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM)/Kelvin probe force microscopy (KPFM) techniques. From the corrosion tests and SEM-AFM/KPFM analysis, the multilayered polymer coated (using polyacrylic acid - PAA) Al6061-T6 alloy experienced a positive shift in the corrosion potential (-0.648 V), signifying a possible corrosion protection ability. With a charge transfer resistance of 2.506×10−6 Ω cm2, and lesser corrosion products featured on the coated sample, the present work demonstrates that the deposition of multilayered polymer PAA coating can enhance the corrosion resistance of Al6061-T6 alloy.</p
Review: Corrosion Resistance Performance of Severely Plastic Deformed Aluminium Based Alloys via Different Processing Routes
No full textAluminium (Al) alloys are known for their high strength and good ductility, making them materials of choice in many aerospace and transport industries. However, they tend to yield to failure in practice as a result of localized corrosion including stress corrosion cracking, exfoliation corrosion, intergranular corrosion, and pitting corrosion. The formation of gradient-structured layers through several severe plastic deformation methods and heat treatments/coatings are the leading possible means of addressing their present shortcomings. The present work reviews the practical ways by which the aforementioned localized corrosion in Al alloys can be reduced to the minimum if not totally eradicated. The corrosion properties of severely plastic-deformed Al alloys obtained via different routes including ultrasonic shot peening, equal-channel angular processing, constrained groove pressing, among others, were extensively reviewed and summarized. The corrosion mechanisms as well as the factors responsible for the improvement or deterioration in corrosion resistance of Al alloys after surface modification were discussed, and the prospects and research trends for future developments are summarized
Passive film analysis and corrosion study of steel type 301 after mechanical deformation
No full textThe electrochemical properties of the passive film formed on surface-modified 301 stainless steel (SS) were examined in the present study. After surface treatment, the passive film analysis was carried out via X-ray photoelectron spectroscopy (XPS) technique, while the surface microstructure of the samples was examined by scanning electron microscope analysis. With Cr 2p, Fe 2p, O 1s, Ni 2p, and C 1s as the principal spectra in the passive film, the Cr 2p spectrum shows two major peaks at 574.3 eV and 583.8 eV corresponding to Cr 2p3/2 (Cr in the metallic state) and Cr 2p1/2, respectively. The Fe 2p spectrum has two major peaks of 707.1 and 720.1 eV corresponding to Fe 2p3/2 (Fe in metallic state) and Fe 2p1/2 peaks, respectively, while the binding energies of 853.3 and 875.1 eV for the Ni 2p spectrum correspond to nickel in the metallic state. The XPS spectra revealed a higher percentage of Cr in the passive film of the treated 301 SS when compared with other elements. From the polarization results, the treated 301 SS possessed a lower corrosion current density of 1.401 mA/cm2 and higher corrosion potential of − 0.085 V
Corrosion Study and Surface Analysis of the Passivation Film on Surface-Deformed AISI 304 Stainless Steel
No full textThe surface analysis of the passivation film formed on surface-deformed AISI 304 stainless steel was carried out in the present study, and its corrosion properties were also determined. The morphology of the surface layer and the phase identification before and after surface modification was examined via scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques, respectively. The composition of the resulting passive film as well as Cr distribution as a function of sputter depth was characterized by X-ray photoelectron spectroscopy (XPS) method. The XPS spectra revealed the existence of Cr, Fe, O, Ni, and C as the principal elements in the resulting passive films formed on the treated 304 steel sample with a high percentage of Cr at the top surface layer. Compared to the untreated sample, the potentiodynamic polarization tests revealed that the treated sample exhibited a better corrosion behavior in terms of higher corrosion potential, lower corrosion current density, and higher impedance.<br/
Corrosion resistance of surface-conditioned 301 and 304 stainless steels by salt spray test
Get PDFThe corrosion rate of surface-conditioned 301 and 304 stainless steels (SS) was determined by salt spray test in a controlled accelerated corrosive medium (9.5 L of pure distilled water + 500 g NaCl). By surface conditioning via mechanical attrition treatment, a gradient-structured layer was firstly generated on the surface of the samples before the salt spray test. The corrosion rate was determined by the weight loss before and after the salt spray test. Compared to the untreated 301 SS sample with a weight loss of 0.15 g, the surface-conditioned samples treated for 300 s and 1200 s experienced a lower weight loss of 0.04 and 0.02 g, respectively. A similar reduction in weight loss was achieved for 304 SS sample when treated for 5, 10, and 20 mins
Corrosion resistance of surface-conditioned 301 and 304 stainless steels by salt spray test
Get PDFThe corrosion rate of surface-conditioned 301 and 304 stainless steels (SS) was determined by salt spray test in a controlled accelerated corrosive medium (9.5 L of pure distilled water + 500 g NaCl). Surface conditioning via mechanical attrition treatment was firstly carried out before the salt spray test. The corrosion rate was determined by weight loss method before and after the salt spray test. Compared to the untreated 301 SS sample with a weight loss of 0.15 g, the surface-conditioned 301 SS samples treated for 300 s and 1200 s experienced a lower weight loss of 0.04 and 0.02 g, respectively. A similar reduction in weight loss was achieved for 304 SS sample when treated for 300, 600, and 1200 s
