The effects of 20 kHz and 500 kHz ultrasound on the corrosion of zinc precoated steels in [Cl−] [SO2−4] [HCO−3] [H2O2] electrolytes

Abstract

The effects of 20 and 500 kHz ultrasound on the corrosion of precoated steels were studied by analysing the behaviour of a zinc coated steel electrode in the corrosion electrolyte [Cl−] [SO2−4] [HCO−3] [H2O2]. The electrolyte was subjected to 20 kHz ultrasound, 500 kHz ultrasound and silent conditions. Zinc plated specimens were exposed to those solutions and growth of the corrosion products was studied by scanning electron microscopy, X-ray microanalysis and grazing incidence X-ray diffraction. Mass transfer measurements were taken on platinum macro- and microelectrodes; they highlighted a specific effect of ultrasound on the growth of zinc corrosion products depending on frequency. Ultrasound greatly influenced corrosion rates; however, the reaction sequence appeared unchanged by the use of an ultrasonic field compared to silent conditions.