A method of inhibiting tarnish formation of silver or silver alloy and corrosion of gold or gold alloy by applying a thin coating of bismuth on the silver, silver alloy, gold or gold alloy. The thin bismuth coating does not compromise the electrical performance of the silver, silver alloy, gold or gold alloy even after thermal aging.

Introducing metal ions into fluids produced from a wellbore may inhibit the formation of scale on downhole production equipment. The ions may be introduced by one or more electrodes disposed in downhole locations such as in a sand control screen assembly, an inflow control device or in a production tubing base pipe. Parameters indicative or predictive of scale formation may be monitored, and an electrical voltage supplied to the electrodes may be adjusted to in response to any predetermined threshold of the parameters being exceeded. In some embodiments, a chemical ion source may be provided, which may release ions in response to erosion or corrosion reaction controlled by electrical power. Electric control of scale production allows for targeted feedback control of the amount of metal ions released as a scale inhibitor without requiring storage of downhole chemical solutions or the passage of fluid lines to downhole locations.

Introducing metal ions into fluids produced from a wellbore may inhibit the formation of scale on downhole production equipment. The ions may be introduced by one or more electrodes disposed in downhole locations such as in a sand control screen assembly, an inflow control device or in a production tubing base pipe. Parameters indicative or predictive of scale formation may be monitored, and an electrical voltage supplied to the electrodes may be adjusted to in response to any predetermined threshold of the parameters being exceeded. In some embodiments, a chemical ion source may be provided, which may release ions in response to erosion or corrosion reaction controlled by electrical power. Electric control of scale production allows for targeted feedback control of the amount of metal ions released as a scale inhibitor without requiring storage of downhole chemical solutions or the passage of fluid lines to downhole locations.

A mixture for coating a metal substrate to prevent or limit scale formation. The mixture comprises 20 to 90% by weight of at least one of: an oxide ceramic material, an aluminosilicate mineral or glass frit. The mixture further comprises 1 to 20% by weight of clay and 3 to 70% by weight of an alkali metal silicate.

A film-forming apparatus is connected to a carbon steel cleanup system pipe of a BWR plant. Formic acid and hydrogen peroxide are injected into the circulation pipe of the film-forming apparatus. An iron elution accelerator aqueous solution containing 3000 ppm of formic acid and 1500 ppm of hydrogen peroxide is brought into contact with the inner surface of the cleanup system pipe, and Fe2+ is eluted from the cleanup system pipe by formic acid, and hydroxyl radicals generated from hydrogen peroxide. The film-forming aqueous solution produced from the iron elution accelerator aqueous solution by injecting the nickel formate aqueous solution is brought into contact with the inner surface of the cleanup system pipe, and the Ni ions incorporated into the inner surface by the substitution reaction are reduced by the electrons generated at the time of elution of Fe2+ to form a Ni metal film on the inner surface thereof.

The invention relates to a method for increasing a corrosion resistance of a component formed with a magnesium-based alloy against galvanic corrosion, in particular micro-galvanic corrosion. According to the invention, an increase in a corrosion resistance against galvanic corrosion is achieved in a simple manner in that a surface layer of the component having a predefined thickness, which surface layer is formed with the magnesium-based alloy, is heated in order to configure the surface layer with a homogenized solid solution phase, whereupon the surface layer is cooled such that the surface layer is formed with a supersaturated solid solution phase. The invention furthermore relates to a corrosion-resistant component which is obtainable by a method of this type.

The invention relates to a method for increasing a corrosion resistance of a component formed with a magnesium-based alloy against galvanic corrosion, in particular micro-galvanic corrosion. According to the invention, an increase in a corrosion resistance against galvanic corrosion is achieved in a simple manner in that a surface layer of the component having a predefined thickness, which surface layer is formed with the magnesium-based alloy, is heated in order to configure the surface layer with a homogenized solid solution phase, whereupon the surface layer is cooled such that the surface layer is formed with a supersaturated solid solution phase. The invention furthermore relates to a corrosion-resistant component which is obtainable by a method of this type.

The present invention provides a method of preventing high temperature corrosion on a heat exchanging surface of a biomass boiler, including: a first feeding step, supplying a first biomass fuel to the boiler; a deposition step, performing combustion on the first biomass fuel during initial operation of the boiler, and forming an inert deposition layer on a surface of a heat exchanger of the boiler; a second feeding step, supplying a second biomass fuel different from the first biomass fuel to the boiler; and a normal combustion step, performing combustion on the second biomass fuel. A direct contact of an alkali metal chloride with a metal pipe wall is prevented by forming an inert deposition layer on the surface of the heat exchanger of the boiler in the deposition step, thereby establishing a physical barrier between the heat exchanging surface of the boiler and the alkali metal chloride to effectively solve a problem of preventing corrosion on the metal pipe wall of the boiler.

The present invention provides a method of preventing high temperature corrosion on a heat exchanging surface of a biomass boiler, including: a first feeding step, supplying a first biomass fuel to the boiler; a deposition step, performing combustion on the first biomass fuel during initial operation of the boiler, and forming an inert deposition layer on a surface of a heat exchanger of the boiler; a second feeding step, supplying a second biomass fuel different from the first biomass fuel to the boiler; and a normal combustion step, performing combustion on the second biomass fuel. A direct contact of an alkali metal chloride with a metal pipe wall is prevented by forming an inert deposition layer on the surface of the heat exchanger of the boiler in the deposition step, thereby establishing a physical barrier between the heat exchanging surface of the boiler and the alkali metal chloride to effectively solve a problem of preventing corrosion on the metal pipe wall of the boiler.

The present invention relates to a method for reducing or preventing the formation or activity of a corrosion-associated biofilm on a metal surface, wherein the method comprises contacting the metal surface with a liquid composition comprising biocidal preparation. The present invention also relates to a microbicidal composition comprising at least one alcohol, one liquid hydrocarbon, a bacteriophage immobilized on a magnetic nanocomposite, at least one phage releasing reagent and one stabilizer. The microbicide composition and method of the present invention reduces biofilms on surfaces, and consequently, reduces, mitigates, or eliminates MIC in internal surface of the oil transporting pipelines.