PAINTING PRE-TREATMENT PROCESSES WITH LOW ENVIORNMENTS IMPACT, AS AN ALTERNATIVE TO CONVENTIONAL PHOSPHATING TREATMENTS

摘要

Disclosed is a process alternative to the zinc phosphating and phosphodegreasing processes, which comprises: Zinc phosphating replacement a. a step of alkaline degreasing of the article to be phosphated; b. a first wash with tap water; c. a second wash with demineralised water; d. a conversion treatment in a bath containing zirconium salts, phosphates, fluoride complexes, ammonia, at least one corrosion inhibitor, at least one process accelerator, at least one sequestering agent, a reaction sludge thickening system, and optionally, titanium and vanadium compounds; e. a final wash before treatment of the article in the oven. Phosphodegreasing process replacement a. a conversion treatment in a bath containing zirconium salts, phosphates, fluoride complexes, ammonia, at least one corrosion inhibitor, at least one process accelerator, at least one sequestering agent, at least one surfactant, a reaction sludge thickening system, and optionally, titanium and vanadium compounds; b. a wash with tap water; c. a wash with demineralised water before treatment of the article in the oven.