The invention comprises synergistic compositions of at least two metal carboxylates as corrosion inhibitors based on polycarboxylate anions and a variety of different cations. The inhibitors are designed to be added to film forming or other compositions to reduce the corrosion of the metal substrate on which the synergistic compositions are applied.

A method includes providing a workpiece with at least one surface having an anodized aluminum coating and a trivalent chromium sealant. The at least one surface of the workpiece is submerged in a post-treatment sealant solution for 0.5 to 20 minutes. The sealant composition consists essentially of a corrosion inhibitor formulation, a water soluble polymer, an organic complexing agent, and an oxidant. The corrosion inhibitor formulation is formulated from at least one anodic corrosion inhibitor compound, at least one cathodic corrosion inhibitor compound, or a combination thereof. A concentration of each of the corrosion inhibitor formulation, the water soluble polymer, the organic complexing agent, and the oxidant is each in a range of 1-50 mM.

The invention provides a liquid composition containing (a) an acidic oxidant, (b) nitric acid or a salt thereof, and (c) at least one carboxylic acid selected from the group consisting of monocarboxylic acids, dicarboxylic acids, and tricarboxylic acids, or a salt thereof. The liquid composition can be used to disinfect or sterilize a subject that includes a portion made of an aluminum-based metal.

An additive comprising one or more C.sub.3-C.sub.12 hydroxycarboxylic acids and/or one or more C.sub.3-C.sub.12 hydroxycarboxylic acid salts may be added to an aqueous system having galvanized metallurgy or a carbon steel surface in an effective amount to passivate a galvanized coating on the metallurgy or to decrease white rust formation or other types of corrosion upon the galvanized metallurgy or carbon steel surface in an aqueous system. In a non-limiting embodiment, the C.sub.3-C.sub.12 hydroxycarboxylic acid or the C.sub.3-C.sub.12 hydroxycarboxylic acid salt additive may utilize the zinc in the galvanized coating to achieve passivation. The passivation may occur while the system is shut down or in service. The aqueous system may be or include a cooling tower, a cooling water system, and combinations thereof. The additive may be used with or in the absence of a phosphorous-containing compound.

A water soluble metalworking concentrate is a combination of one or more amines; one or more ferrous corrosion inhibitors; one or more phosphate esters; one or more ether carboxylates; a ricinoleic acid condensate; one or more lubricating agents; deionized water and, optionally, one or more non-ferrous corrosion inhibitors. In use, the concentrate is diluted to a concentration of approximately 5% to approximately 10%. In use, the metalworking fluid exhibits excellent lubricity, low foam generation, emulsion stability, protection of ferrous and non-ferrous metals, biostatic stability and environmental compatibility.

An organic blend chemical additive comprising more than 50 wt. % organic solvent (e.g. methanol and/or ethylene glycol), less than 10 wt. % water, a nitrate salt, a maleic acid copolymer, and optionally an imidazoline may be delivered to a production well through a conduit having a stainless steel and corrosion resistant metal alloy surface, such as a capillary string or an umbilical tubing, the organic blend chemical additive being shown to be useful in inhibiting localized corrosion of and improving the repassivation of the equipment or conduit.

The present invention relates to novel corrosion inhibitor compositions for magnesium or magnesium alloys and to a process for inhibiting the corrosion of such metals using such compositions. The corrosion inhibitor composition for magnesium or magnesium alloys comprises at least one corrosion inhibiting compound which is capable of forming a complex with at least one of Fe(II), Fe(III), Cu(I), Cu(II) and Ni(II) ions, where the complex with at least one of Fe(II), Fe(III), Cu(I), Cu(II) and Ni(II) ions has a stability constant in aqueous solution at room temperature (about 21 C.) log K of greater than or equal to 3.5 wherein the corrosion inhibiting compound is selected from the group of pyridinedicarboxylic acids, and their salts or esters thereof.

Corrosion inhibitor formulations for use in heat transfer fluids include: (a) an optionally substituted benzoic acid or a salt thereof; (b) at least a first n-alkyl monocarboxylic acid or a salt thereof and a second n-alkyl monocarboxylic acid or a salt thereof, the first n-alkyl monocarboxylic acid and the second n-alkyl monocarboxylic acid being different; and (c) an azole compound. A ratio of weight percent of the first n-alkyl monocarboxylic acid or the salt thereof to weight percent of the second n-alkyl monocarboxylic acid or the salt thereof ranges from about 1:0.75 to about 1:2.00. A ratio of weight percent of the benzoic acid or the salt thereof to combined weight percent of the first n-alkyl monocarboxylic acid or the salt thereof and the second n-alkyl monocarboxylic acid or the salt thereof ranges from about 1:0.30 to about 1:2.25.

In this invention the use of glucamides in combination with at least one sulfur-based synergist chosen from the group of thiols, thioethers, thiosulfates, thioglycolic acids, thiourea or derivatives thereof in a formulation for corrosion inhibition in the gas and oil industry is described.

The present invention relates to antifreeze/anticorrosive concentrates, to processes for production of such concentrates from superconcentrates, to aqueous coolant compositions made from these concentrates and to the use thereof.