Laser surface cladding process of boiler pipe anticorrosive layer

Abstract

The invention relates to a laser surface cladding process, in particular to a laser surface cladding process of a boiler pipe anticorrosive layer. Detergent is used for removing oil and rust of a boiler pipe at the room temperature; a part to be treated is checked by using a dye penetrant inspection method; nickel-based alloy powder is fed in a laser molten pool by adopting a coaxial or paraxonic powder feeding device, and comprises the following chemical components in percentage by weight: 0.01-0.05% of C, 21-22% of Cr, 1.0-2.0% of Fe, 8-10% of Mo, 0.1-0.7% of Si, 3.5-4.2% of Nb, and 63-64.5% of Ni; a corrosion and abrasion resistant layer is formed on the surface of the part to be treated; and the process parameters are as follows: a focusing mirror F is 300-400 mm; the cladding power P is 2000-5000 W; the spot size D is 3-10 mm; the scanning speed V is 200-1000 mm/min; the overlap rate is 40-60%; and the crack flaw detection is performed for the prepared cladding coating layer. The laser surface cladding process enhances the high-temperature corrosion and oxidization resistance of the boiler pipe, prolongs the service life of the boiler pipe, reduces the production cost, largely improves the production efficiency of power plant boilers, and promotes the development of coal, coal power and coal chemical industry in the east junggar basin region.

Description

technical field [0001] The invention relates to a laser surface cladding process, in particular to a laser surface cladding process for a boiler tube anticorrosion layer. Background technique [0002] During the use of the high-temperature section of the boiler, the main failure mode is that a large area of ​​strong cohesive ash is formed in the high and low areas, accompanied by severe high-temperature corrosion, resulting in a large-area tube burst. Forced to shut down the furnace to remove dust and replace the pipes. At present, the common practice at home and abroad is to use arc spraying to prepare a layer of protective layer with excellent anti-corrosion function on the surface of the water-cooled wall; the second is to change the material of the furnace tube to improve its corrosion resistance; the third is to strictly control the combustion Composition of coal to reduce the presence of sulfur and other harmful impurities. Affected by the constraints of domestic...

AI Technical Summary

Problems solved by technology

However, in the face of Zhundong coal's high moisture, high coking, and serious contamination characteristics, the current boiler tube material and spraying protective layer methods cannot achieve results, which greatly limits the large-scale use of this coal type in power plant