Optimized process control in the anti-corrosive metal pretreatment based on fluoride-containing baths

US10458022B2 · kind B2 · utility

Assignee

• Henkel AG & Co. KGaA · DE

Inventors

• Jan-Willem Brouwer · Willich, DE
• Christian Stromberg · Goldkronach, DE
• Frank-Oliver Pilarek
• Jens Kroemer · Neuss, DE
• Fernando Jose Resano Artalejo · Dressendorf, DE
• Natascha Henze · Leverkusen, DE

Key dates

• Filing date: Jun 9, 2017
• Grant date: Oct 29, 2019
• Expiry date: Apr 6, 2038

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C23C22/86
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

A method for corrosion protection treatment, comprising contacting a series of components having metallic surfaces of iron and/or zinc with a passivating aqueous pretreatment solution, present in a system tank, containing compounds of the elements zirconium and/or titanium, and contacting with a source of fluoride ions wherein a portion of the pretreatment solution is discarded and replaced with a volume portion of one or more such replenishment solutions which in total are at least of equal size, by metered addition to the system tank of the pretreatment and wherein discarding as a function of the molar ratio of the elements fluorine to zirconium and/or titanium must not drop below a predefined value, the metered addition of replenishment solution takes place such that maintaining the concentration of the elements zirconium and/or titanium in the passivating aqueous pretreatment solution in the form of water-soluble compounds is ensured.