BATH AND PROCESS FOR THE PHOSPHATIZATION OF METALLIC SUBSTRATES, CONCENTRATES FOR THE PREPARATION OF SAID BATH AND METALLIC SUBSTRATES HAVING BEEN SUBJECTED TO A TREATMENT BY SAIDBATH AND PROCESS

摘要

The invention relates to a bath and to a process for the phosphatization of metallic substrates as well as a metallic substrate having been subjected to said treatment by the said bath and process. The bath according to the invention, whose pH is from 1 to 5.5 and comprising the classical components of the phosphatization baths, is characterized by the fact that it comprises - from about 0.3 to about 25 g/l of zinc ion, preferably from 0.5 to 10 g/l, - from 5 to about 50 g/l of phosphate ion, preferably from 8 to 30 g/l, et - from about 0.01 to about 10 g/l, preferably from 0.03 to 3 g/l of a trivalent cobalt complex represented by one of the formulae (I) or (II). No figure.