Laser remelting method for steel electric arc spraying aluminum coating layer used for ocean platform

Abstract

The invention relates to the technical field of steel surface modification processing, in particular to a laser remelting method for a steel electric arc spraying aluminum coating layer used for an ocean platform, in order to solve the problem that the seawater corrosion resistant capacity of the coating layer is improved without increasing the thickness of the coating layer, and belongs to a material surface modification composite processing technology. By means of a electric arc spraying technology, a layer of the aluminum coating layer is prepared by using the surface of a steel base material on the ocean platform, then a laser remelting technology is used to iron melt the aluminum coating layer and the surface of a substrate, and after cooling is conducted, a Fe-Al alloy layer is formed; the surface of the coating layer is flat, the structure property can be improved, alloy combination is formed between the coating layer and the base material, a few amorphous state aluminum is generated in the coating layer, and the corrosion resistant performance of the coating layer can be improved.

Description

technical field [0001] The invention relates to the technical field of steel surface modification treatment for offshore platforms, in particular to a laser remelting method for arc spraying aluminum coatings on steel surfaces for offshore platforms, in order to solve the problem of improving the seawater corrosion resistance of the coating without increasing the thickness of the coating The problem belongs to the composite treatment technology of material surface modification. Background technique [0002] Offshore platforms are mainly used in the exploitation of offshore oil and natural gas. Due to the continuous development of oil and gas exploration areas to deep sea areas, offshore platforms will be subject to more severe physical and chemical corrosion such as typhoons, waves, tides, salt spray, electrolytes, and marine microorganisms; Especially in the wave splash area, the corrosion rate of steel is 6 times that of normal conditions, and a small amount of dam...

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Problems solved by technology

[0002] Offshore platforms are mainly used in the exploitation of offshore oil and natural gas. Due to the continuous development of oil and gas exploration areas to deep sea areas, offshore platforms will be subjected to more severe physical and chemical corrosion such as typhoons, waves, tides, salt spray, electrolytes, and marine microorganisms; Especially in the wave splash area, the corrosion rate of steel is 6 times that of normal conditions. A small amount of damage to the steel surface of the pile legs will lead to the generation of closed batteries, which will accelerate its corrosion rate, and the application of mobile offshore platforms has a great impact on offshore platforms. The anti-corrosion period puts forward new requirements; arc spraying aluminum is a long-term anti-corrosion process for metal surfaces. The theoretical service life of a 200μm thick aluminum coating in seawater is 30 years. In a strong tidal range environment, its service life is significantly reduced. Simply increasing the thickness of the coating to prolong the service life of the offshore platform will affect the mechanical properties of its load-bearing device; with the increase of the spray thickness, the voids in the coating , holes and other spraying defects will increase significantly; secondly, the combination of the aluminum coating and the substrate is a small amount of metallurgical bonding and a large amount of mechanical bonding, and the increase in the thickness of the coating will lead to the overall peeling off of the coating

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