Corrosion rates were investigated in terms of inhibitor compositions i
n order to find synergism or antagonism between components. The intera
ctions between inhibitors were taken into account by second order equa
tions. Examination of regression coefficients and their significance i
ndicated that synergism may exist if concentrations of inhibitor compo
unds are 30 mg dm(-3) and below, but if the inhibitor compounds are ap
plied in concentrations of 100 mg dm(-3), antagonism, rather than syne
rgism takes place.