The following conclusions, based on the results ob tamed, can be made:1. After corrosion treatment of Zn-Mn alloys with different manganese content and phase composition in free aerated neutral model medium with presence of corrosion activators Cl ions the compound ZHC appears on the specimen surface. It has a low product of solubility (10~(-14.2) mol/L)~9 and ensures higher protective ability in comparison with the pure zinc.2. ZHC forms readily only in the case when manganese is available. Galvanic coatings of the intermetallic Zn-Mn compound produce more thick and compact ZHC layers than samples containing the Zn-Mn (approx 6 percent) coatings in similar conditions of corrosion treatment.3. Contrary to other zinc alloys, Zn-Mn passivates in 5 percent NaCl solution at external anodic polarization due to the formation of ZHC. The newly created passive film consists entirely from this compound, but not from oxides and hydroxides as in other corrosion media. For example, the ZHC appears at a pH value of about 7.0 to 7.5, while the Zn(OH)_2 at pH values higher than 10.0.4. The results for this alloy at E_(corr) can be compared with our previous results from salt-spray-chamber. ~3 Chromated samples of Zn-Mn (approx 11 percent) resist up to 300 hours till 2.5 percent of their surface is damaged. Chromated pure zinc specimens from a slightly acidic bath and chromated samples of Zn-Mn (approx 6 percent) endure at these conditions almost 180 hours. ~3
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