A conversion layer based on trivalent chromium and cobalt for the corrosion protection of electrogalvanized steel

Sarli, Alejandro Ramón Di; Culcasi, José Daniel; Tomachuk, Célia Regina; Elsner, Cecília Inês; Ferreira, José Maria F.; Costa, Isolda

doi:10.1016/j.surfcoat.2014.08.057

Cited by 27 publications

(14 citation statements)

References 68 publications

(68 reference statements)

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“…According to the fitting result and previous researches on formation mechanism of chromate conversion coating on steel, zinc, aluminum, magnesium, etc., when the as‐plated coating immerses in the passivation solution, the redox reactions are induced:

{normalC normalr}_{2} {normalO}_{7}^{2 ‐} + 3 normalN normali prefix+ 14 H^{+} ® 2 {normalC normalr}^{3 prefix+} + 7 H_{2} normalO prefix+ 3 {normalN normali}^{2 prefix+}

{normalC normalr}_{2} {normalO}_{7}^{2 ‐} + 3 normalC normalu prefix+ 14 H^{+} ® 2 {normalC normalr}^{3 prefix+} + 7 H_{2} normalO prefix+ 3 {normalC normalu}^{2 prefix+}

normalN normali prefix+ {normalC normalu}^{2 prefix+} ® {normalN normali}^{2 prefix+} + normalC normalu

{normalC normalr}_{2} {normalO}_{7}^{2 ‐} + 3 normalN normali prefix+ 14 H^{+} {normalC normalr}^{3 prefix+} + 7 H_{2} normalO prefix+ 3 {normalN normali}^{2 prefix+}

…”

Section: Resultsmentioning

confidence: 98%

Effect of Cu in electroless Ni–Cu–P coating on passivation process

Gan

Zhao

Kang

et al. 2016

Surface & Interface Analysis

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Electroless Ni-P and Ni-Cu-P coatings were passivated by chromate conversion treatment respectively. The anticorrosive performances of passivated coatings were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy measurements. The passivated Ni-Cu-P coating exhibited a high corrosion resistance with the i corr of 0.236 μA/cm, 2 while the value of passivated Ni-P coating was only 1.030 μA/cm, 2 indicating the passive film could improve the corrosion resistance of Ni-Cu-P coating to a significant extent. High-resolution X-ray photoelectron spectroscopy was used to determine the chemical states of elements detected in the passive film. Compared with passivated Ni-P coating, the passive film on Ni-Cu-P coating exhibited a higher ratio of Cr 2 O 3 to Cr(OH) 3 with the value of 72:28, which was the main factor for passivated Ni-Cu-P coating showing excellent corrosion resistance. The effect of Cu in electroless Ni-Cu-P coating on passivation process was discussed by the contrast experiment.

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{normalC normalr}_{2} {normalO}_{7}^{2 ‐} + 3 normalN normali prefix+ 14 H^{+} ® 2 {normalC normalr}^{3 prefix+} + 7 H_{2} normalO prefix+ 3 {normalN normali}^{2 prefix+}

{normalC normalr}_{2} {normalO}_{7}^{2 ‐} + 3 normalC normalu prefix+ 14 H^{+} ® 2 {normalC normalr}^{3 prefix+} + 7 H_{2} normalO prefix+ 3 {normalC normalu}^{2 prefix+}

normalN normali prefix+ {normalC normalu}^{2 prefix+} ® {normalN normali}^{2 prefix+} + normalC normalu

{normalC normalr}_{2} {normalO}_{7}^{2 ‐} + 3 normalN normali prefix+ 14 H^{+} {normalC normalr}^{3 prefix+} + 7 H_{2} normalO prefix+ 3 {normalN normali}^{2 prefix+}

…”

Section: Resultsmentioning

confidence: 98%

Effect of Cu in electroless Ni–Cu–P coating on passivation process

Gan

Zhao

Kang

et al. 2016

Surface & Interface Analysis

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“…12(b). It has been noted that the Cr 2p 3/2 and Cr 2p 1/2 at binding energy of 579.4 and 586.6 eV, respectively, were very closed to the of Cr 2p peaks in K 2 Cr 2 O 7 which suggested the Cr 6+ [51,52]. But from Fig.…”

Section: Stability and Prove Of Photo-reductionmentioning

confidence: 87%

Fabrication of mesoporous CuO/ZrO 2 -MCM-41 nanocomposites for photocatalytic reduction of Cr(VI)

Nanda

Pradhan

Parida

2017

Chemical Engineering Journal

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h i g h l i g h t sMesoporous ZrO 2 -MCM-41synthesized by in situ incorporation process. CuO@ZM-41 synthesized by modification of CuO onto the ZrO 2 -MCM-41. CuO@ZM-41nacomposite shows semiconductor behavior and mesoporosity. High surface area, lower e À and h + recombination are enhancing the photo-reduction. g r a p h i c a l a b s t r a c tMesoporous nanocomposite (CuO@ZM-41) is synthesized by incorporating mesoporous ZrO 2 (Z) into MCM-41 (M-41) framework followed by loading of CuO by wetness impregnation method. The synergism between CuO and the support material mesoporous ZM-41 and efficient light absorption on the surface of the composite is the key factor for the reduction Cr 6+ to Cr 3+ within 30 min time. a b s t r a c tMesoporous nanocomposites of CuO/ZrO 2 -MCM-41 (CuO@ZM-41) was designed by incorporating mesoporous ZrO 2 (Z) into the high surface area MCM-41 (M-41) framework followed by loading CuO by wetness impregnation method keeping Si/Zr ratio 10. The nanocomposites were studied under PXRD, N 2 sorption, DRS spectra, FTIR, XPS, NMR, HRTEM and PL to evaluate structural, morphological, optical properties and also the mesoporosity nature of the samples. The photo-reduction of Cr 6+ was performed over CuO@ZM-41 by varying pH, substrate concentration, and irradiation time and catalyst dose. Among all the catalysts, 2 CuO@ZM-41 was found to be efficient photocatalyst for the photo-reduction of Cr 6+ . Nearly 100% reduction of Cr 6+ has been achieved by 2 CuO@ZM-41 within 30 min. Intra-particle mesoporosity, high surface area, presence of CuO nanorods and electron transfer properties are the key factors for enhancing the photo-reduction activity of 2CuO@ZM-41.

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“…Thanyalux WANOTAYAN, 1) Yuttanant BOONYONGMANEERAT, 2) Joongjai PANPRANOT, 3) Eiji TADA 4) and Atsushi NISHIKATA 4) * trochemical impedance spectroscopy (EIS) is especially suitable for monitoring the degradation of galvanized steels exposed to accelerated corrosion tests and natural environments because it is a non-destructive method. The corrosion rate can be estimated from the charge transfer resistance that appears in the lower frequency region.…”

Section: Electrochemical Evaluation Of Corrosion Resistance Of Trivalmentioning

confidence: 99%

“…Electrogalvanized chromate steels are widely used for corrosion protection in various applications, including automotive, construction, and electrical. [1][2][3][4] To apply the coating, a steel substrate is submerged and electrochemically plated in a zinc bath and subsequently dipped in a chromiumbased passivation solution. The alkaline non-cyanide zinc plating solution and Cr 3 + -based passivation solution are environmentally-friendly chemicals that are available for these processes.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Evaluation of Corrosion Resistance of Trivalent Chromate Conversion Coatings with Different Organic Additives

et al. 2018

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The corrosion resistance of electrogalvanized steels with trivalent chromate conversion coatings is investigated electrochemically to analyze the effect of organic additives on the corrosion resistance under wet-dry cyclic conditions. Three sets of polyamine additives, namely (i) imidazole and epihalohydrin, (ii) polyquaternary amine salt, and (iii) polyethyleneimine, are examined and compared. Electrochemical impedance spectroscopy and anodic stripping were employed to evaluate the corrosion resistance. Crystal-structure and compositional analyses were also applied to demonstrate the role of organic additives in controlling the structure of the zinc layer and the formation of the trivalent chromate conversion film.

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A conversion layer based on trivalent chromium and cobalt for the corrosion protection of electrogalvanized steel

Cited by 27 publications

References 68 publications

Effect of Cu in electroless Ni–Cu–P coating on passivation process

Effect of Cu in electroless Ni–Cu–P coating on passivation process

Fabrication of mesoporous CuO/ZrO 2 -MCM-41 nanocomposites for photocatalytic reduction of Cr(VI)

Electrochemical Evaluation of Corrosion Resistance of Trivalent Chromate Conversion Coatings with Different Organic Additives

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