The phase analysis of the rusts generated beneath the primer containing micaceous iron oxide (MIO) and micaceous iron oxide
in combination with red lead (RL), zinc phosphate (ZP), basic lead silicochromate (BLSC) and zinc chromate (ZC) has been carried
out by Mössbauer spectroscopy at room temperature. The rust beneath the coating obtained after immersion of the painted panel
for six months in 3% NaCl, consists mainly of nonstoichiometric magnetite together with small fractions of γ-, α-FeOOH except
in the case of panel painted with RL containing MIO showed only a central doublet indicating the formation of γ-FeOOH and
SPM α-FeOOH. Non-stoichiometry of magnetite as calculated from the ratio of B/A sites of the peaks of magnetite in the spectrum
has been found depending on the nature of anticorrosive pigment present in the primer coating. The order of non-stoichiometry
has been found to be in order of ZC>BLSC>ZP>MIO.