Method for preparing erosion-wear-resisting composite coating

Abstract

This invention relates to a surface engineering field used in the protection of power station boiler pipelines including: spot welding a layer of hardness alloy lattice on a cleaned metal matrix with self-protection metal core weld sticks, in which, the weld current is 180-220A, voltqge is 18-22V, welding point space is 2-5mm, diameter of the welding point is 4-5mm and the height is 2-3mm, the welded metal matrix is sprayed with sand to eliminate the oxidized skins, rust and the old coating and expose the metallic brightness then a compound layer of anti-erosion and anti-abrasion is sprayed on the matrix by an arc spraying method.

Description

Technical field: [0001] The invention belongs to the field of coating preparation in material processing engineering, and the invention is mainly applied to the protection of power plant boiler pipes. Background of the invention: [0002] With the rapid growth of my country's economy, the demand for electricity is increasing. In the power structure, my country's firepower equipment accounts for more than 3 / 4 of the total installed capacity, and the situation of excessive firepower will last for a long period of time. Therefore, accelerating the development of high-efficiency, low-pollution thermal power units and accelerating the development of clean coal combustion technology is the development direction of my country's thermal power technology. The circulating fluidized bed (CFB) boiler not only solves the problem of efficient and rational utilization of energy, but also greatly reduces the emission of pollutants. As an environment-friendly boiler, it can burn various fu...

AI Technical Summary

Problems solved by technology

[0003] In circulating fluidized bed boilers, the boiler pipes are in harsh environments such as high temperature, vulcanization, fly ash, slag, etc., and the generated flue gas contains a large number of hard fly ash particles. When the convective heating surface tube bundles, the surface of the tube wall is severely worn, resulting in serious damage to the local heating surface, and even causing tube explosion and leakage, resulting in shutdown accidents, causing great direct and indirect losses to the national economy

The most severely worn area of ​​the circulating fluidized bed boiler tube is at the junction of the combustion zone and the water wall. The general wear-resistant coating cannot guarantee the safe operation of the boiler during an overhaul period. Therefore, a corrosion-resistant wear-resistant coating was developed. Coating is very important

[0004] Commonly used arc spraying anti-erosion wear protective coating is easy to crack and peel off under a large impact load because the bonding mode between the coating and the substrate is mechanical bonding and very little metallurgical bonding, and the coating thickness is also limited. Within 1mm, if it is too thick, it is easy to peel off due to the accumulation of residual stress in the coating, and the low bonding strength and thin coating are not enough to effectively and durably protect power plant boiler pipes in a highly erosive environment. protection of

Images