Abstract:Zinc diffusion kinetics of double-phase brass as they were corroded in seawater was investigated by means of metallography microscope and mathematics regression analysis. The results showed that, the dezincification corrosion ofβ-phase continuous HMn58-2 brass is characterized byβ-phase volume diffusion, while that ofα-phase continuous HSn62-1 brass is controlled byα-phase grain boundary diffusion. Apparent diffusion coefficients of zinc in both types alloys were calculated out by founding diffusion equation and boundary conditions. It was found that the value of theoretical calculation is close to that of experimentally measured, and it confirmed that Sn element inhibits dezincification of brass. The relativity between the dezincification depth and corrosion rate of different double-phase brasses immersed in seawater was revealed.

Key words: seawater corrosion; brass; dezincification; boundary diffusion