Formation of the main atmospheric zinc end products: NaZn sub 4 Cl(OH) sub 6 SO sub 4 mult6H sub 2 O, Zn sub 4 SO sub 4 (OH) sub 6 multnH sub 2 O and Zn sub 4 Cl sub 2 (OH) sub 4 SO sub 4 mult5H sub 2 O in [Cl exp - ][SO sub 4 exp 2- ][HCO sub 3 exp - ][H sub 2 O sub 2 ] electrolytes

• Published in: Corrosion science Vol. 41; no. 6; pp. 1139 - 1164
• Main Authors: Ligier, V, Wery, M, Hihn, J Y, Faucheu, J.,-, Tachez, M
• Format: Journal Article
• Language: English
• Published: 01.06.1999
• ISSN: 0010-938X

The composition of new accelerated zinc corrosion electrolytes has been derived from the chemistry of atmospheric pollutants. Zinc plated specimens were exposed to these solutions and the growth of the corrosion products has been studied by means of scanning electron microscopy, x-ray microanalysis and grazing incidence x-ray diffraction. First, the main atmospheric zinc end products were identified according to different natural environments, i.e. NaZn sub 4 Cl(OH) sub 6 SO sub 4 6H sub 2 O for a marine atmosphere, Zn sub 4 SO sub 4 (OH) sub 6 nH sub 2 O for a rural environment and Zn sub 4 Cl sub 2 (OH) sub 4 SO sub 4 5H sub 2 O developed in industrial and urban atmospheres. Then, the corrosion sequences were estalished for the 3 electrolytes able to reproduce mechanisms close to the atmospheric corrosion sequences of zinc when it is exposed to marine, rural, urban and industrial atmospheres. Accelerated corrosion tests performed in such electrolytes would advantageously replace cyclic automobile test solutions by improving the resemblance between accelerated corrosion results and natural ones.