Provided herein is a process for the pretreatment of workpieces having a surface of aluminum or aluminum alloys for noncutting forming and/or joining by welding or adhesive bonding to similarly pretreated, precoated workpieces, or to optionally precoated parts. The parts are composed of steel, galvanized steel, and/or alloy-galvanized steel. Further provided herein is a subsequent permanent corrosion-protecting treatment by phosphating, by means of a chromium-free conversion treatment, by application of primer, or by surface coating, where the workpieces are a) pickled by means of an aqueous, acidic solution comprising mineral acid by dipping or spraying, b) rinsed with water, and c) brought into contact with an aqueous, acidic, chromium-free solution including Zr as complex fluoride and Mo as molybdate by application by dipping or spraying. After subsequent drying, a layer weight from 2 to 15 mg/m.sup.2 of Zr and Mo is formed.

Provided herein is a process for the pretreatment of workpieces having a surface of aluminum or aluminum alloys for noncutting forming and/or joining by welding or adhesive bonding to similarly pretreated, precoated workpieces, or to optionally precoated parts. The parts are composed of steel, galvanized steel, and/or alloy-galvanized steel. Further provided herein is a subsequent permanent corrosion-protecting treatment by phosphating, by means of a chromium-free conversion treatment, by application of primer, or by surface coating, where the workpieces are a) pickled by means of an aqueous, acidic solution comprising mineral acid by dipping or spraying, b) rinsed with water, and c) brought into contact with an aqueous, acidic, chromium-free solution including Zr as complex fluoride and Mo as molybdate by application by dipping or spraying. After subsequent drying, a layer weight from 2 to 15 mg/m.sup.2 of Zr and Mo is formed.

The present invention addresses the problem of providing, a metal surface treatment agent capable of exhibiting excellent corrosion resistance and excellent coating adhesion in painted metal materials; and a metal surface treatment method using the metal surface treatment agent. The problem is solved by a pretreatment agent that is used in a pretreatment of a chemical conversion treatment performed for forming a chemical conversion coating on/over a surface of a metal material, the pretreatment agent containing: a metal alkoxide (A) containing at least one metal element selected from zirconium, titanium, vanadium, and aluminum; and at least one sulfonic acid (B) selected from methanesulfonic acid, ethanesulfonic acid, hydroxymethanesulfonic acid, and hydroxyethanesulfonic acid. The problem is also solved by a chemical conversion treatment agent that contains a zirconium alkoxide (a) and a zirconium-containing ion supply source (b), and has a pH of 1.5 to 6.5.

The present invention addresses the problem of providing, a metal surface treatment agent capable of exhibiting excellent corrosion resistance and excellent coating adhesion in painted metal materials; and a metal surface treatment method using the metal surface treatment agent. The problem is solved by a pretreatment agent that is used in a pretreatment of a chemical conversion treatment performed for forming a chemical conversion coating on/over a surface of a metal material, the pretreatment agent containing: a metal alkoxide (A) containing at least one metal element selected from zirconium, titanium, vanadium, and aluminum; and at least one sulfonic acid (B) selected from methanesulfonic acid, ethanesulfonic acid, hydroxymethanesulfonic acid, and hydroxyethanesulfonic acid. The problem is also solved by a chemical conversion treatment agent that contains a zirconium alkoxide (a) and a zirconium-containing ion supply source (b), and has a pH of 1.5 to 6.5.

The invention relates to an inorganic aqueous surface treatment agent for a single-face electrogalvanized, chromium free surface treated steel plate, a single-face electrogalvanized, chromium-free surface treated steel plate used for fuel tanks and a process of making the same. The inorganic aqueous surface treatment agent for a single-face electrogalvanized, chromium free surface treated steel plate comprises the following components: one or more metallic ion compounds comprising at least one of Zn.sup.2+, Mn.sup.2+, Mg.sup.2+, Ni.sup.2+, Al.sup.3+ and Ca.sup.2+; one or more vanadium compounds comprising at least one of V.sup.4+ and V.sup.5+; one or more compounds comprising at least one of phosphoric acid, pyrophosphoric acid, metaphosphoric acid, organic phosphoric acid and the ammonium salts thereof; one or more fluoric acid compounds comprising at least one of Zr, Ti, Si and Ha; one or more silane coupling agents comprising at least one of vinyl silane coupling agent, amino silane coupling agent, epoxy silane coupling agent and acryloxy silane coupling agent; a silica sol having a particle diameter less than 100 nm; one or more surfactants comprising at least one of carboxylate, sulfuric acid ester salt, sulfonate and phosphoric acid ester salt; wherein the total solid content in the inorganic aqueous surface treatment agent is 2 wt %-20 wt % of the surface treatment agent. The process for preparing the single-face electrogalvanized chromium-free surface treated steel plate used for fuel tanks comprises the steps of coating the plated surface of the single-face electrogalvanized steel plate with the above surface treatment agent, solidifying at a temperature of 70-100 C., and finally oil finishing on the surface to produce a skin film resulting from the surface treatment with a weight of 100-600 mg/m.sup.2.

Disclosed is a zirconium-based metal pretreatment coating composition that includes a metal chelator that chelates copper in the metal pretreatment coating composition and thereby improves adhesion of paints to a metal substrate coated with the pretreatment coating composition and the chelating agent is present in a sufficient amount to ensure that in the deposited pretreatment coating on the metal substrate the average total atomic % of copper to atomic % of zirconium is equal to or less than 1.1. The pretreatment coating composition is useful for treating a variety of metal substrates.

Disclosed is a zirconium-based metal pretreatment coating composition that includes a metal chelator that chelates copper in the metal pretreatment coating composition and thereby improves adhesion of paints to a metal substrate coated with the pretreatment coating composition and the chelating agent is present in a sufficient amount to ensure that in the deposited pretreatment coating on the metal substrate the average total atomic % of copper to atomic % of zirconium is equal to or less than 1.1. The pretreatment coating composition is useful for treating a variety of metal substrates.

Provided herein is a process for the pretreatment of workpieces having a surface of aluminum or aluminum alloys for noncutting forming and/or joining by welding or adhesive bonding to similarly pretreated, precoated workpieces, or to precoated parts. The parts are composed of steel, galvanized steel, and/or alloy-galvanized steel. Further provided herein is a subsequent permanent corrosion-protecting treatment by phosphating, by means of a chromium-free conversion treatment, by application of primer, or by surface coating, wherein the workpieces are a) pickled by means of an aqueous, acidic solution comprising mineral acid by dipping or spraying, b) rinsed with water, and c) brought into contact with an aqueous, acidic, chromium-free solution comprising Zr as complex fluoride and Mo as molybdate by application by dipping or spraying. After subsequent drying, a layer weight from 2 to 15 mg/m.sup.2 of Zr and Mo is formed.

Disclosed herein is a pretreatment composition comprising a Group IVB metal in an amount of 200 ppm to 5.000 ppm based on total weight of the pretreatment composition, total fluoride in an amount of 1.000 ppm to 25.000 ppm based on total weight of the pretreatment composition and an electropositive metal. Also disclosed herein is a pretreatment composition comprising a Group IVB metal in an amount greater than 500 ppm based on total weight of the pretreatment composition and free fluoride in an amount of 50 ppm to 750 ppm based on total weight of the pretreatment composition, wherein the pretreatment composition has a pHI greater than 4. Also disclosed herein are systems and methods for treating a substrate. Also disclosed herein are treated substrates.

A method for the manufacture of a substrate provided with a chromium VI-free and a cobalt-free passivation by the application of a first acidic passivation and a second alkaline passivation, containing a silane-modified and/or a siloxane modified silicate, with which an improved protection against corrosion is achieved, an aqueous, acidic composition for passivating and a passivated substrate, and a device for applying the passivation.