Abstract: Influence of NH4Cl on the initial atmospheric corrosion of zinc was investigated via quartz crystal microbalance (QCM) in laboratory at 80%RH and 25℃. The results show that NH4Cl can accelerate the initial corrosion of zinc. Mass gain increase with the exposure time, but mass gain in the later doesn't change obviously due to the formation of the insoluble simonkolleite on zinc surface in the presence of NH4Cl. Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) was used to characterize the corrosion products. Zn5Cl2(OH)8·H2O, (NH4)2ZnCl4 and ZnO are the corrosion products on zinc. Brief discussion on the mechanisms of atmospheric corrosion of zinc in the presence of NH4Cl was introduced.

Key words: atmospheric corrosion, zinc, NH4Cl