Abstract: 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.