Corrosion Behavior Of Zinc Research Articles

Corrosion behavior of magnesium, aluminum and zinc as anodic materials in chloride based electrolytes for use in primary and secondary electrochemical power sources

Corrosion behavior of magnesium, aluminum and zinc in 0.2 mol dm −3 NH 4Cl; 0.1 mol dm −3 NH 4Cl with addition of 0.1 mol dm −3 Na-citrate and corrosion behavior of zinc in 0.3 mol dm −3 NH 4Cl with addition of 0.8 mol dm −3 Na-citrate and different concentration of ZnCl 2 were investigated. Corrosion current densities were determinated from the mass lost and from potentiodynamic (1 mV s −1) measurements. It was concluded that magnesium and aluminum are not suitable anodic materials for use in primary electrochemical power sources. On the other hand, it was concluded that zinc could be considered as possible anodic material in both primary and secondary electrochemical power sources.

Corrosion Behavior of Zinc, Galvanized, Mild Steel in Water-Concrete Environment

Abstract Types and causes of underlying corrosion processes must be determined precisely for each construction element exhibiting signs of deterioration, so that the selected repair works and protection methods are adequate. Only then will the protection and repairs be appropriately durable; this, in turn, will reduce the costs of building maintenance. The corrosion cause analysis of selected construction elements hereby presented is based on research conducted on the buildings as well as on laboratory and structural (microscopy and x-ray microanalysis) research.

The erosive wear and corrosion behavior of zinc- and aluminum-coated steels in simulated coastal environment

The telecommunication systems outside plants are made of a variety of materials; metals, alloys, polymers, concrete and so on. The interaction between the outside plant metal components and the environment leads to various types of corrosion. Metal-coated steel wires are widely used as supports for telecommunication cables. In coastal areas the metal-coated steel wire corrodes and even fractures in a short time. A two-step laboratory test, salt-spray after sand blast, was designed to simulate windy coastal environments and this test was adopted to evaluate the zinc- and aluminum-coated steel. This paper describes the mutual action of sand abrasion and marine corrosion that can lead to premature failure of the metallic coatings in the tropical coastal area. The results also show that the aluminum-coated steel performed only 60% better than the zinc-coated steel. Also it was found the erosive wear of zinc- and aluminum-coated steels fit a ductile-cutting model.

Zinc corrosion in simulated acid rain

Corrosion behavior of zinc in a simulated acid rain has been investigated by electrochemical impedance spectroscopy, atomic emission plasma spectroscopy and X-ray photoelectron spectroscopy. It was found that corrosion rate increases drastically in the solution of lower pH near 3. Corrosion potential shifts to less noble value with increasing pH at the lower pH 2.5 and shifts to more noble value at the higher pH 2.9. An oxide film of about 1 μm thick is revealed on zinc surface at pH 3.6, and no film is detected at pH 2.1. Electrochemical impedance diagram has an inductive loop for the solution of higher pH 3.2, while only depressed capacitive-loops are observed at pH below 2.9. The magnitude of the impedance diagram rises with the increasing period of immersion at higher pH 3.2, and decreases at lower pH 2.3. The phenomena observed are discussed in terms of Zn 2+ diffusion rate and change in the oxide film thickness.

Corrosion Characteristics of Chromated Zinc in Sodium Chloride Solutions

Abstract The corrosion behavior of zinc with a chromate conversion coating containing ∼ 0.02 g/m2 Cr(VI) was investigated. X-ray photoelectron spectroscopy (XPS) showed Cr(VI) was located in layers near the surface of the coating. Corrosion current densities and Cr(VI) content in the coating decreased with immersion time. An electrochemical reduction of Cr(VI) to Cr(III) parallel to oxygen (O2) reduction in the first stages of immersion was reviewed. Inhibition of the corrosion rate proceeded simultaneously with dissolution of the conversion coating. It was concluded that the thickness of the coating was not the most important factor to hinder O2 reduction. Corrosion inhibition was attributed to zinc surface passivation byproducts of ionization.

自動車用Zn及びZn系合金めっき鋼板の塗膜下腐食挙動

自動車用Zn及びZn系合金めっき鋼板の塗膜下腐食挙動

A Study of the Inhibiting Action of Benzene Thiols and Related Compounds on the Corrosion of Zinc in Acidic Media

Abstract The effect of benzenethiol and its methyl, amino, and carboxylic ring substituted derivatives, benzylthiol and thioglycollic acid on the electrochemical and corrosion behavior of zinc in CH3COOH, H2SO4, and HCl solutions was studied using the galvanostatic technique. In CH3COOH, compounds which function by an adsorption mechanism were found to have inhibitive effects on the corrosion of zinc, while those functioning by surface chelation were ineffective. In H2SO4 and HCl, with the exception of o-methylbenzenethiol (H2SO4 and HCl) and benzylthiol (H2SO4), all investigated compounds were found to accelerate zinc dissolution. Adsorption of the inhibitors followed the Langmuir isotherm, and the mechanism of both the hydrogen evolution reaction and zinc dissolution were found to be the same in the uninhibited and inhibited states.

The Effect of Several Electrode and Electrolyte Additives on the Corrosion and Polarization Behavior of the Alkaline Zinc Electrode

The corrosion behavior of zinc in at 25° C was investigated through measurement of the rate of hydrogen evolution at the corrosion potential. Anodic and cathodic potentiostatic polarization curves as a function of alloying and additions to the electrolyte were obtained. It was found that the corrosion and polarization behavior of 99.999% zinc can be explained by mixed‐potential theory assuming that the reactions were . Good agreement between theoretical curves obtained by computer solution of the kinetic equations corresponding to the above reactions and actual polarization measurements was obtained in the absence and presence of zincate. Theoretical and experimental corrosion rates also agreed well. Binary alloys [0.2–1.0 w/o (weight per cent)] and alloys (0.2–0.8 w/o) made up from high‐purity metals had values which were lower than those for zinc, while values of commercial zinc alloys were much higher than those of zinc, most likely due to the presence of low overvoltage impurities such as Cu, Ni, or Fe. Addition of 10−3M copper, tin, or lead ions to the electrolyte also influenced , which in the presence of metal ions noble to zinc is no longer equivalent to the corrosion rate. The strong increase of in the presence of Cu ions is explained by the low hydrogen overvoltage of Cu, while the decrease of in the presence of Pb ions is explained by the high hydrogen overvoltage of Pb. Anions such as Cl− or Br− do not affect . In the presence of thiourea, increases steadily, while S2− leads to severe corrosion.