摘要:
PROBLEM TO BE SOLVED: To provide an atmospheric corrosion inhibitor capable of inhibiting the atmospheric corrosion of carbon steel in an environment with severe corrosiveness including chloride such as sea salt mist and sea sand, and to provide a coating material, carbon steel and a heat insulating material.SOLUTION: An atmospheric corrosion inhibitor to carbon steel includes at least one selected from the alkali metal salt of tetraboric acid and 15 to 20C aliphatic amine as an active ingredient, and is preferably used in the air including fine solid matter such as salt-containing sand and dust in particular.
摘要:
PROBLEM TO BE SOLVED: To provide a corrosion prevention method of a structural metal material that does not form a corrosion prevention coating on a surface of the structural metal material that comes into contact with a stagnant water.SOLUTION: In a corrosion prevention method of a structural metal material 20 that comes into contact with a stagnant water 60, an addition metal ion 41 for corrosion prevention that is an ion of the same metal element as a corrosion forming metal ion 40 as a metal ion generated when the structural metal material 20 corrodes is supplied into the stagnant water 60.
摘要:
PROBLEM TO BE SOLVED: To provide a method for effectively preventing corrosion of an economizer in a boiler having the economizer using exhaust gas heat of the boiler for boiler feed-water.SOLUTION: The method for preventing corrosion of an economizer using the exhaust gas heat of the boiler for heating boiler feed-water includes continuously passing water to the economizer by continuously operating a feed-water pump for feeding water to the boiler.
摘要:
PROBLEM TO BE SOLVED: To provide a method of estimating corrosion of a water system conveniently enabling management of an oxidizing agent-based slime control agent in a job site even when a plurality of oxidizing agents coexist in the water system.SOLUTION: The method of estimating the corrosion of the water system adds a halogen-based oxidizing agent reagent in water sampled from the water system and after addition, obtains free residual halogen concentration after passing a prescribed time. The corrosion of the water system is estimated on the basis of the correlation of the free residual halogen concentration of ORP obtained previously. The prescribed time is normally 5-180 seconds, and does not exceed 5-30 seconds in particular.
摘要:
A bath containing nickel ions and formic acid is injected into a film-forming aqueous solution flowing in a circulation pipe connected to a feed water pipe made of carbon steel in a BWR plant. This solution is supplied into the pipe through the circulation pipe, and a nickel metal film is formed on an inner surface of the pipe. After the film is formed, a film-forming aqueous solution containing iron (II) ions, formic acid, nickel ions, hydrogen peroxide, and hydrazine is supplied to the pipe. A nickel ferrite film is formed on the surface of the nickel metal film in the pipe. The nickel ferrite film comes into contact with water containing dissolved oxygen at or above 150° C. to transform the nickel metal film into a nickel ferrite film. A thick nickel ferrite film is formed on the inner surface of the feed water pipe.
摘要:
PROBLEM TO BE SOLVED: To provide a degreasing device having a mechanism to suppress rust formation due to galvanic corrosion of the galvanic cell formed between a metal product and a degreasing solution.SOLUTION: In the degreasing device which has an alkaline immersion degreasing tank 5 for degreasing the metal product 4, electron emission and metal ion elution due to galvanic corrosion of the galvanic cell formed between the metal product 4 and the degreasing solution are suppressed by installing an insulation part 6 on a grounding route between the metal product 4 and a peripheral dissimilar metal. Thereby a reaction of an eluted metal ion with a hydroxide ion is suppressed and rust formation can be suppressed.
摘要:
PROBLEM TO BE SOLVED: To provide a corrosion control method, by which a titanium foil can be adhered to the surface of a steel structure so as to be able to impart better corrosion-proof capability to the steel structure.SOLUTION: The corrosion control method, employed for coating the surface of a steel structure with a titanium foil to control corrosion, comprises the coating step of coating the surface of a steel material composing the steel structure with a coating material so as to form a coating layer, the coating step of coating a part on the surface of the coating layer, other than the weld bead part of the steel material, with the titanium foil, and the adhesion step of adhering a titanium tape to portions not coated with the titanium foil on the surface of the coating layer.