Construction method for weldable wear-proof thick coating

Abstract

The construction process of forming thick antiwear coating includes the following steps: sand blasting the base material and arc spraying to form an antiwear weldable coating of 0.5 mm thickness; spot welding with heat resistant stainless weld rod to form 2.0-3.5 mm height weld spots in 50-60 mm interval on the surface and reaching to the base material; roughening the weld spots and arc spraying to form an antiwear coating of 2-3.5 mm thickness; polishing the weld spots to the same plane as the coating; and final hole sealing treatment of the coating. The thick antiwear coating has great thickness and high bonding strength, and is especially suitable for boiler pipes.

Description

[0001] Technical method [0002] The invention relates to a paint construction technology, in particular to a coating construction technology for improving the bonding strength of the coating and increasing the thickness of the coating through spot welding and rough surface treatment. Background technique [0003] For a long time, there has been no fundamental breakthrough in the field of arc spraying wear protection. Since the coating and the substrate are mechanically bonded, the thickness of the coating is limited by the bonding strength, and due to the physical, chemical and mechanical properties of the coating. , the thickness of the coating generally does not exceed 1 mm, even if a composite coating is used, it cannot exceed the forbidden zone of 2 mm or more. However, with the promotion and use of high-parameter and large-capacity circulating fluidized bed boilers, the wear of furnace tubes is becoming more and more serious. The thinner anti-wear coating obtained by con...

AI Technical Summary

Problems solved by technology

[0003] For a long time, there has been no fundamental breakthrough in the field of arc spraying wear protection. Since the coating and the substrate are mechanically bonded, the thickness of the coating is limited by the bonding strength, and due to the physical, chemical and mechanical properties of the coating. , the thickness of the coating generally does not exceed 1 mm, and even if a composite coating is used, it cannot exceed the forbidden area of ​​2 mm or more.

However, with the promotion and use of high-parameter and large-capacity circulating fluidized bed boilers, the wear of furnace tubes is becoming more and more serious. The thinner anti-wear coating obtained by conventional arc spraying is far from meeting the needs of boiler anti-wear. There are some disadvantages as follows:

[0004] 1. Due to the irregular movement of the layer-containing smoke, the degree of wear is inconsistent. Some parts of the coating wear quickly and fail, while some parts wear less

[0005] 2. Due to the different degree of scouring and unbalanced force, the phenomenon of partial loss of coating is serious

[0006] 3. With the occurrence of falling blocks, some bosses will appear, which will intensify the wear and tear

[0007] 4. Since the thermal expansion coefficients of the coating and the substrate are not exactly the same, the coating is easy to fall off under the action of alternating thermal stress, which will affect the normal operation of the equipment in severe cases