Repair method for steel storage tank corrosion pit

Abstract

The invention relates to a repair method for a steel storage tank corrosion pit and belongs to the technical field of welding. A pit after repair comprises three parts, including aluminum for filling up the pit, an aluminum-sprayed erosion resistant coating on the inner surface and a carbon fiber sheet back-up coat on the outer surface. In the repair method, the aluminum for filling up the pit plays the roles of smoothing tank wall and facilitating construction of the erosion resistant coating in later period and delaying of tank wall corrosion because the erosion resistant coating is used as a positive pole after corrosion perforation; the aluminum-sprayed erosion resistant coating on the inner surface can isolate direct contact between stored matter and steel of the tank wall and play the roles of delaying or even stopping further erosion and protecting the tank wall; the carbon fiber sheet back-up coat on the outer surface plays the roles of solidifying the tank body and shearing internal pressure so as to prevent discarding of the storage tank caused by the fact that the tank wall is thinned and cannot bear internal pressure. The combined use of the three parts can lastingly and effectively protect and solidify the storage tank.

Description

technical field [0001] The invention relates to a method for repairing corrosion pits of steel storage tanks, belonging to the technical field of welding. Suitable for storing H in substances + Defect repair and tank reinforcement of steel storage tanks with low content levels and pit corrosion depths less than 1 / 2 tank wall thickness. Background technique [0002] With the development of the national economy, storage tanks have been widely used in the fields of industrial production and transportation, and have played a very important role in the production, storage and transportation of oil and gas materials, liquid chemical materials and other substances. And over time, in H 2 Under the joint action of substances such as S, water vapor and air, the steel storage tank will be gradually corroded, and defects such as pits will appear on the inner surface, which will seriously threaten the safe use of the storage tank and shorten the service life of the storage tank. There...

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Problems solved by technology

The above-mentioned invention has the following problems: ① The pit defect has not been filled, anti-corrosion and other treatments, and it may still be a weak link after reinforcement; ② The carbon fiber cloth layer directly pasted on the inner surface may react with the substances stored in the tank and be damaged. ③Put putty on the surface of the tank body and carbon fiber cloth will reduce the bonding force between carbon fiber cloth and tank body, carbon fiber cloth and carbon fiber cloth

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