Improved corrosion inhibitors for well brines include a phosphonate or salts thereof, and a gluconic acid or salts thereof. The inhibitors are normally injected downhole into the brines. The most preferred phosphonates are amine polyphosphonates, used in combination with alkali metal salts of gluconic acid.

A method is disclosed for treating an anodized metal surface. According to the method, polynuclear clusters comprising aluminum oxide hydroxide are applied to the anodized metal surface.

A method is disclosed for treating an anodized metal surface. According to the method, polynuclear clusters comprising aluminum oxide hydroxide are applied to the anodized metal surface.

A cleaning liquid and an anticorrosion agent having an excellent corrosion inhibition function, and a method for manufacturing the same. The cleaning liquid contains alkanol hydroxyamine represented by general formula (1), alkanolamine represented by general formula (2), a solvent, and a basic compound other than the alkanol hydroxyamine and the alkanolamine or an acidic compound. In the general formula (1), R.sup.a1 and R.sup.a2 each independently represents a C1-C10 alkyl group having one to three hydroxy groups, or a hydrogen atom, R.sup.a1 and R.sup.a2 are not simultaneously a hydrogen atom, and R.sup.b1 and R.sup.b2 are not simultaneously a hydrogen atom.

##STR00001##

A cleaning liquid and an anticorrosion agent having an excellent corrosion inhibition function, and a method for manufacturing the same. The cleaning liquid contains alkanol hydroxyamine represented by general formula (1), alkanolamine represented by general formula (2), a solvent, and a basic compound other than the alkanol hydroxyamine and the alkanolamine or an acidic compound. In the general formula (1), R.sup.a1 and R.sup.a2 each independently represents a C1-C10 alkyl group having one to three hydroxy groups, or a hydrogen atom, R.sup.a1 and R.sup.a2 are not simultaneously a hydrogen atom, and R.sup.b1 and R.sup.b2 are not simultaneously a hydrogen atom.

##STR00001##

A corrosion-resistant coating on an aluminum-containing substrate such as an aluminum substrate, an aluminum alloy substrate (e.g., AA 2024, AA 6061, or AA7075), or other aluminum-containing substrate includes a corrosion inhibitor-incorporated ZnAl layered double hydroxide (LDH) layer and a sol-gel layer. A zinc salt and a corrosion inhibitor (e.g., a salt of an oxyanion of a transition metal such as a vanadate) is dissolved to form a zinc-corrosion inhibitor solution, and the substrate is immersed in or otherwise contacted with the solution to form the corrosion inhibitor-incorporated ZnAl LDH layer on the substrate. A sol-gel composition is applied on the corrosion inhibitor-incorporated ZnAl LDH layer of the substrate to form a sol-gel layer, and the sol-gel layer is cured.

A corrosion-resistant coating on an aluminum-containing substrate such as an aluminum substrate, an aluminum alloy substrate (e.g., AA 2024, AA 6061, or AA7075), or other aluminum-containing substrate includes a corrosion inhibitor-incorporated ZnAl layered double hydroxide (LDH) layer and a sol-gel layer. A zinc salt and a corrosion inhibitor (e.g., a salt of an oxyanion of a transition metal such as a vanadate) is dissolved to form a zinc-corrosion inhibitor solution, and the substrate is immersed in or otherwise contacted with the solution to form the corrosion inhibitor-incorporated ZnAl LDH layer on the substrate. A sol-gel composition is applied on the corrosion inhibitor-incorporated ZnAl LDH layer of the substrate to form a sol-gel layer, and the sol-gel layer is cured.

A method of improving corrosion resistance of a metal substrate comprising a zinc surface coated with zirconium oxide conversion coating by, prior to conversion coating, contacting the zinc surface with a composition comprising: a) iron(III) ions, b) a source of hydroxide ion; c) at least one complexing agent selected from organic compounds which have at least one functional group COOX, wherein X represents either a H or an alkali and/or alkaline earth metal; d) 0.0 to about 4 g/l cobalt (II) ions; and optionally e) a source of silicate: wherein the composition has a pH of at least 10.

A method of improving corrosion resistance of a metal substrate comprising a zinc surface coated with zirconium oxide conversion coating by, prior to conversion coating, contacting the zinc surface with a composition comprising: a) iron(III) ions, b) a source of hydroxide ion; c) at least one complexing agent selected from organic compounds which have at least one functional group COOX, wherein X represents either a H or an alkali and/or alkaline earth metal; d) 0.0 to about 4 g/l cobalt (II) ions; and optionally e) a source of silicate: wherein the composition has a pH of at least 10.

Methods for inhibiting corrosion, cleaning and/or providing biocidal efficacy in hydrogen rich environments that are in hydrogen systems or hydrogen mediums using saturated alkyl diquaternary compound containing compositions, saturated alkyl quaternary compound containing compositions, aldehyde containing compositions, and/or tetrakis(hydroxymethyl)phosphonium sulfate containing compositions are provided. The methods provide efficacious corrosion inhibition, cleaning and/or biocidal efficacy without loss of stability due to hydrogenation in hydrogen rich environments.