THE EFFECT OF MICRO-DROPLETS FORMATION CAUSED BYTHE DELIQUESCENCE OF THE DEPOSITED SALT PARTICLEON ATMOSPHERIC CORROSION OF METALS

摘要

Salt particle deliquescence on metal surface is one of the main causes for atmospheric corrosion initiation.It is observed recently that after a salt particle deliquesces and forms a droplet, a large amount ofmicro-droplets formed and grow-up surround the primary droplet. This work studied the characteristic ofmicro-droplets formation and its relation to atmospheric corrosion initiation. It is found out thatmicro-droplets formation rested with the RH and the corrosiveness of the primary-droplet solution to themetal, and micro-droplet zone exhibited cathodic character with higher pH and positive potential. Theresults revealed that micro-droplet formation depends on the RH which should be higher than that of oversaturated solution of the primary droplet, at the first, and the corrosiveness of the primary-droplet solutionto the metal, at the second. In addition, it is confirmed that the mocro-droplet can be formed only oncathodic zone around the primary droplet.