In an oxidising environment,
they are transformed into nitrates that, as ammonium salts, contribute to corrosion
by creating Cu(NH3)n Æ x complexes, where x can be 2Cl or 2NO
3 or SO2
4 and n can
range from 1 to 4. In the presence of such complexes, the copper passivity area disappears.
Nitrites can make a transient compound in the nitrate-ammonium transformation.