4. Metals likely to be phosphated

Mechanical parts or sheet metal assemblies are, as a general rule, phosphated on finished products. The steels are therefore in their final metallurgical structure, obtained by the appropriate heat treatments, and in their machined finished state specific to their use; they may also have already undergone mechanical or mechanochemical surface preparation (tribofinishing).

Phosphating can be carried out on all structures where the steel's chemical composition permits (see table 6 ).

However, the surface must be free of amorphous or passive layers 5