Materials Chemistry and Physics, Vol.198, 243-249, 2017
Study on corrosion behavior of zinc exposed in coastal-industrial atmospheric environment
The corrosion behavior of zinc subjected to Liaoning Hongyanhe nuclear power station (a typical coastal industrial atmospheric environment) has been investigated by weight-loss measurement, scanning electron microscopy (SEM) observation, x-ray diffraction (XRD), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The experimental results reveal that the corrosion kinetics of the corrosion of zinc in coastal-industrial atmospheric environment followed empirical equation D = At, and with the increase of the exposure time polarization resistance (RP) and charge transfer resistance (R-ct) increased, the corrosion rate decreased gradually. XRD, SEM and EDS indicated that the depth and width of all pits increased with time and the surface corrosion gradually transformed into a uniform corrosion. The components of the rust layers were composed of Zn-5(CO3)(2) (OH)(6), NaZn4SO4 CI(OH)(6)center dot 6H(2)O and Zn-12(OH)(15)Cl-3(SO4)(3)center dot 5H(2)O. In the initial exposure period, the corrosion products was Zn-5(CO3)(2)(OH)(6), while with prolonged exposure, a two -layer structured corrosion products formed, which were comprised of NaZn4(SO4)CI(OH)(6)center dot 6H(2)O and Zni(2)(OH)(15)Cl-3(SO4)(3)center dot 5H(2)O, all these products were flaky-structured and compact enough to provide excellent protection. (C) 2017 Elsevier B.V. All rights reserved.