Localized Dissolution of Zn-Al Alloy Coated Steel in Neutral Solution with Cl<SUP>-</SUP> by Photon Rupture Method

Influence of Zinc Ions on Initial Stage of Localized Corrosion of Zn and Zn–Al Alloy Coated Steels with Photon Rupture Method

“…In previous work, we reported that these fluctuations were related to gas evolution, growth and detachment. [13][14][15] From this figure, the corrosion protection effect of Zn ions is hindered if the layer has small amount of Al, but the mechanism is not fully elucidated. Figure 11 shows a schematic representation of the possible mechanism of the effect of Zn ions on dissolution of the coated layer.…”

“…The irradiation with a pulsed laser beam is able to strip oxide film at extremely high rates without contamination from the removing tool of the film. This technique has been applied to localized corrosion of iron by Oltra et al 9) and by Itagaki et al, 10) and to localized corrosion of Zn and Zn-Al alloycoated steel by Sakairi et al [11][12][13][14][15] The authors have studied the behavior of artificial pits formed by photon rupture method on Zn and Zn alloy-coated steels, and reported that the direction of the rest potential shift was affected by the area ratio of the coated layer (Zn or Zn-Al alloy) to the steel in artificial pits. [16][17][18] Immediately after laser irradiation, the rest potential shifted to the negative direction while the coated layer was exposed to the solution, then, after the steel substrate becomes exposed to the solution, the rest potential shifted to the positive direction.…”

Initial Stage of Localized Corrosion in Artificial Pits Formed with Photon Rupture on 55mass%Al–Zn Coated Steels

“…The irradiation with a pulsed laser beam is able to strip oxide film at extremely high rates without contamination from the film removing tools. This technique has been applied to iron by Oltra et al 14) and by Itagaki et al,15) and to aluminum electrodes, 16) and to zinc and its aluminum alloy coated steel by Sakairi et al [17][18][19][20][21][22][23][24][25] This technique has also been applied to form micro patterns on metals, 26,27) and Sakairi et al has reported on the effect of zinc and steel area ratios in artificial pits, which were formed on coated steels by photon rupture, on the rest potential change direction. 28) After laser irradiation, the rest potential changes in the negative direction while the zinc coated layer is exposed to the solution,.…”