Electrochemical behavior of thermally sprayed stainless steel coatings in 3.4% NaCl solution

2005 ◽  
Vol 47 (3) ◽  
pp. 605-620 ◽  
Author(s):  
P.H. Suegama ◽  
C.S. Fugivara ◽  
A.V. Benedetti ◽  
J. Fernández ◽  
J. Delgado ◽  
...  
Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 835
Author(s):  
Alexandre R. C. Nascimento ◽  
Samantha Michelle Gateman ◽  
Janine Mauzeroll ◽  
Sylvio Savoie ◽  
Robert Schulz ◽  
...  

Thermally sprayed stainless-steel coatings were produced with a wide range of deposition parameters. The electrochemical behavior of polished coatings was monitored for 3 weeks in 3.5 wt.% NaCl aqueous solution and compared to that of reference materials including a wrought stainless steel plate and a bulk ingot produced by arc melting of the spraying powder feedstock. Transitions in the polarization behavior are discussed based on the observed changes in coating microstructures as well as on the shifts in X-ray photoelectron spectra (XPS). Results show that the deposition parameters have a strong effect on the coating microstructures but the small differences in the polarization behavior of coatings mostly disappear after 1 week of testing. Microstructure evidence shows preferential corrosion at splats experiencing melting prior to deposition. Pitting and corrosion products between splat boundaries are also reported. XPS analysis shows that the coating surfaces are enriched in chromium oxides and hydroxides. Comparison between the coating and bulk stainless steels suggests that coating inherent defects play a major role on their impaired corrosion resistance.


2021 ◽  
Vol 10 (5) ◽  
pp. e32810513544
Author(s):  
Cecília Alves de Sousa ◽  
Carolina Ferrairo Danieletto-Zanna ◽  
Thamara Beline ◽  
Gustavo Zanna Ferreira ◽  
Leonardo Perez Faverani ◽  
...  

This study evaluated the effect of disinfection procedures and exposure to 0.9% NaCl solution cycles during sterilization, on the electrochemical, physical and chemical properties of different stainless steel alloys used in the biomedical field. Discs of F899 XM16, F899 303, and F899 420B alloys were cleaned with enzymatic detergent followed by 20 cycles of autoclave sterilization. Electrochemical tests were performed including open circuit potential, electrochemical impedance spectroscopy, and potentiodynamic polarization tests in 0.9% NaCl (n=5). Surface characterization was performed using scanning electron microscopy (SEM), energy dispersive spectroscopy, and surface roughness and microhardness both before and after the electrochemical test. Quantitative data were analyzed with a significance level of 5%. The corrosion current density and corrosion potential of the alloys did not present statistical differences. The capacitance values of the three oxide layers, polarization resistance, and impedance of Warburg were similar among the alloys. Considering the topography, surface roughness increased for all alloys in the post-corrosion period. The stainless steel alloys analyzed were negatively affected at the electrochemical behavior, corrosion kinetics, and surface characterization after the 0.9% NaCl solution and the autoclave sterilization cycles, confirming the need for regular exchanges of surgical instruments and drills used in medical and dental implantology.


The effect of electrochemical behavior of plasma sprayed NiCr–Cr2O3 (80:20) and Al2O3– 40% TiO2 as coating on stainless steel 316L were investigated. The polarization studies were carried out in 1.0M H2SO4 and 3.5% NaCl solution as a corrosive medium. The corrosion potential is more positive in the coated sample and gives good corrosion resistance when compared to bare sample. The surface characterization studies were carried out through electron microscope attached with energy dispersive spectroscopy. It was found that intergranular attack and pitting corrosion takes place in the sample exposed in 1.0M H2SO4 and large crater was found in the sample exposed in 3.5% NaCl solution.


2019 ◽  
Vol 27 (04) ◽  
pp. 1950140
Author(s):  
T. MANA ◽  
A. ATI ◽  
B. ZAID ◽  
N. SOUAMI

In this work, multicomponent Al-bronze alloys coated Tin-Bronze substrates, fabricated by thermal flame spraying, are characterized by X-ray diffraction and scanning electron microscopy coupled with energy dispersive spectroscopy. Mechanical characterizations are also presented: microhardness measurement and friction coefficient. The electrochemical behavior of tin-bronze samples uncoated and coated with multicomponent Al-Bronze coatings is studied in NaCl 3.5% solutions using potentiodynamic polarization curves and polarization resistance measurements. The microstructure of the coatings has a lamellar morphology. Each lamella is constituted of a mixture of Cu3Al globular micro precipitates ([Formula: see text]-phase) uniformly distributed over the solid solution matrix ([Formula: see text]-Cu). An oxide based on Cu, Al and Fe is also present in very low concentration. [Formula: see text]-phase is unexpected because it is present only above 570∘C in the Cu-Al phase diagram. Compared with the tin-bronze substrate, multicomponent Al-bronze coatings show a friction coefficient three times lower and have a better electrochemical behavior in 3.5% NaCl solution.


2018 ◽  
Vol 90 (9) ◽  
Author(s):  
Tomasz Babul ◽  
Anna Olbrycht ◽  
Szymon Pawlik ◽  
Janusz Trojanowski

Hybrid technologies are one of the directions of materials engineering development. They contribute to the subject of research on improving the performance of thermally sprayed steel coatings by thermo-chemical treatment. The paper presents the test results of arc spraying stainless steel coatings and then glow-discharge nitrided. The glow-discharge nitriding was performed with the following parameters: at 450 °C for 6 hours and at 530 °C for 4 hours. The results of the following tests are described and presented: metallographic (SEM), qualitative and quantitative analysis point EDS, measurement of hardness HV, hardness distribution, measurement of roughness parameters (Ra, Rz), wear resistance by the Amsler method. The results showed that the glow-discharge nitriding increases the hardness and the frictional wear resistance of thermal sprayed stainless steel X46Cr13 and X2CrNi18-9 coatings. The hybrid technology, combining thermal spraying of martensitic stainless steel X46Cr13 and glow-discharge nitriding at 530 °C for 4 hours, provides formation of a coating with the highest hardness and wear resistance of all the tested coatings. This coating can be applied to the regeneration of machine parts, which are required to have particularly high useful properties.


Author(s):  
V.V. Dushik ◽  
◽  
G.V. Redkina ◽  
N.V. Rozhanskii ◽  
T.V. Rybkina ◽  
...  

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