PRE-PAINTING MULTIMETAL PHOSPHATING PROCESS WITH LOW ENVIRONMENTAL IMPACT

摘要

Disclosed is a multimetal phosphating process which comprises the following steps: a) immersion of the metal part to be treated in an activating bath containing titanium polyphosphates and organic nitro compounds deriving from nitroguanidine; b) transfer of the metal part from the activation bath to a phosphating bath containing zinc, manganese, P2O5, chlorates, fluorosilicates and hydrogen peroxide.