Disclosed herein is a method for pretreatment of a metallic substrate for a subsequent metal cold forming process, said method including (1) providing at least one substrate, (2) contacting the at least one surface of the substrate provided in step (1) with an aqueous lubricant composition (A). and optionally (3) drying the coating film obtained after having performed step (2). Further disclosed herein are a pretreated metallic substrate obtainable by the aforementioned method, a method of cold forming of a metallic substrate including a step of subjecting the inventive pretreated metallic substrate to a cold forming process, an aqueous lubricant composition (A) as defined above, and a master batch for preparing the aqueous composition (A).

Disclosed herein is a method for pretreatment of a metallic substrate for a subsequent metal cold forming process, said method including (1) providing at least one substrate, (2) contacting the at least one surface of the substrate provided in step (1) with an aqueous lubricant composition (A). and optionally (3) drying the coating film obtained after having performed step (2). Further disclosed herein are a pretreated metallic substrate obtainable by the aforementioned method, a method of cold forming of a metallic substrate including a step of subjecting the inventive pretreated metallic substrate to a cold forming process, an aqueous lubricant composition (A) as defined above, and a master batch for preparing the aqueous composition (A).

The present application provides an anti-corrosion super-slippery aluminum capillary tube and method and device for preparing the same. The preparation starts with the etching and drying of the inner walls of an aluminum capillary tube, which leads to the formation of an alumina capillary structure surface with micro-nano scale roughness. Next, the alumina capillary structure surface is modified to form a low surface energy modifying layer. Finally, the modified alumina capillary structure surface is wetted by a prewetting solution, so that a continuous film of the prewetting solution is formed on the inner wall of the aluminum capillary tube to function as a lubricating layer. The lubrication layer, on one hand, reduces the flow resistance for convey of liquid media, on the other hand, prevents the conveyed liquids from directly contacting the aluminum capillary tube body, thereby avoiding the corrosion of the aluminum capillary tube by corrosive liquids.

The present invention relates to a method for forming a black-passivation layer on a zinc-iron alloy of a substrate, a black-passivation composition for depositing a black-passivation layer on such, in which the black-passivation composition includes one or more than one blackening agent selected from the group consisting of formula (I) and formula (II) as described hereinafter, and a respective use of said blackening agents for blackening a zinc-iron alloy.

The invention relates to a method for producing a silane-modified silicate. In order to obtain optimal corrosion protection properties, a silane compound according to the invention is at least partially hydrolyzed and/or condensed in the presence of a silicate compound at a pH value greater than or equal to 8 and then a pH value less than or equal to 7 is set by adding acid. The invention further relates to an aqueous acidic passivation composition for metal substrate coated with the passivation composition.

Provided herein is a reductive solution for preventing rouge formation on stainless steel, said solution comprising complexing anions, Fe.sup.2+, and, optionally, one or more pH modifiers. Further provided are methods for manufacturing said solution, methods for prevention of rouge formation on stainless steel surfaces, and related uses of the aforementioned reductive solution.

An aqueous acidic composition is provided for forming a chromium-containing chemical conversion coating on a member having an iron-based metal surface. The composition contains a water-soluble trivalent chromium-containing substance, a water-soluble zinc-containing substance, and a water-soluble polyvalent carboxylic acid compound. On the total composition basis, the water-soluble trivalent chromium-containing substance has a content of 60 mmol/L or more in terms of chromium, the water-soluble zinc-containing substance has a molar content in terms of zinc such that a ratio of the content is 0.6 or more to a molar content in terms of chromium of the water-soluble trivalent chromium-containing substance, and the water-soluble polyvalent carboxylic acid compound has a content of 55 mmol/L or more in terms of polyvalent carboxylic acid. The composition is free from allylamine, polyallylamine, aromatic sulphonic acid, aromatic sulphonic acid-formaldehyde condensate, and derivatives thereof, and fluorine-based substance, hexavalent chromium-containing substance, and film-forming organic component.

An aqueous acidic composition is provided for forming a chromium-containing chemical conversion coating on a member having an iron-based metal surface. The composition contains a water-soluble trivalent chromium-containing substance, a water-soluble zinc-containing substance, and a water-soluble polyvalent carboxylic acid compound. On the total composition basis, the water-soluble trivalent chromium-containing substance has a content of 60 mmol/L or more in terms of chromium, the water-soluble zinc-containing substance has a molar content in terms of zinc such that a ratio of the content is 0.6 or more to a molar content in terms of chromium of the water-soluble trivalent chromium-containing substance, and the water-soluble polyvalent carboxylic acid compound has a content of 55 mmol/L or more in terms of polyvalent carboxylic acid. The composition is free from allylamine, polyallylamine, aromatic sulphonic acid, aromatic sulphonic acid-formaldehyde condensate, and derivatives thereof, and fluorine-based substance, hexavalent chromium-containing substance, and film-forming organic component.

Provided is a zinc-based plated steel sheet having a post-treated coating filmed thereon including: a steel sheet; a zinc plated layer formed on the steel sheet; and a post-treated coating formed on the plated layer, wherein the atomic ratio (O/M) of oxygen (O) to metals (M) contained in the post-treated coating is greater than 2 and less than 20, and a method for post-treating a zinc-based plated steel sheet. According to this, the zinc-based plated steel sheet having the post-treated coating formed thereon has the effects excellent in lubricity, weldability, adhesiveness, film-removing property and paintability. As the method of post-treating a zinc-based plated steel sheet of the present invention employs a simple coating method irrespective of the kind of plating layer, the process is simple and economical and the process operation cost is low.

Provided is a zinc-based plated steel sheet having a post-treated coating filmed thereon including: a steel sheet; a zinc plated layer formed on the steel sheet; and a post-treated coating formed on the plated layer, wherein the atomic ratio (O/M) of oxygen (O) to metals (M) contained in the post-treated coating is greater than 2 and less than 20, and a method for post-treating a zinc-based plated steel sheet. According to this, the zinc-based plated steel sheet having the post-treated coating formed thereon has the effects excellent in lubricity, weldability, adhesiveness, film-removing property and paintability. As the method of post-treating a zinc-based plated steel sheet of the present invention employs a simple coating method irrespective of the kind of plating layer, the process is simple and economical and the process operation cost is low.