Flange surface insulation processing method

Abstract

The invention belongs to the technical field of surface engineering coating, and relates to the electrostatic powder spraying technology of surface engineering. The method comprises five steps: abrasive blasting, spraying, sintering, secondary spraying and sintering, and post-processing. An electrostatic spraying sintering method is used for depositing poly(ether-ether-ketone) powder on a butt joint surface of a flange and in a part of a pipe, and there is a certain distance away from a welding part. The surface of the flange is provided with a reliable flat insulating coating layer with the thickness from 300 microns to 500 microns, and the insulating coating layer is low in water absorption, is good in insulating effect, enables different types of metal at two ends of the flange to be isolated, is good in extruding resistance for the flange when a ship or a metal engineering structure deforms, can provide a good isolation protection effect, and effectively avoids the gap corrosion caused by the galvanic corrosion caused by the isolation elimination of different types of metal, pipe connection spacer aging and pipe miniature deformation. The method is simple, is reliable in principle, is low in preparation cost, is good in insulating effect, is long in validity period, is environment friendly, and is wide in application range.

Description

Technical field: [0001] The invention belongs to the technical field of surface engineering coating, relates to electrostatic powder spraying technology of surface engineering, in particular to a flange surface insulation treatment method, which can effectively prevent galvanic corrosion and crevice corrosion that occur when dissimilar metal materials are in contact. Background technique: [0002] The contact between dissimilar metal materials in ships and other metal engineering is unavoidable. Galvanic corrosion and crevice corrosion are common corrosion forms of flanges, especially flange flanges due to water absorption and aging of flange gaskets, or pipeline corrosion. Due to the micro-deformation under force, cracks appear, which cause serious corrosion or even perforation of crevice corrosion-sensitive materials such as copper, titanium and stainless steel. Corrosion failure accidents of metal components occur frequently, which accelerates the damage and aging of metal...

AI Technical Summary

Problems solved by technology

[0002] The contact between dissimilar metal materials in ships and other metal engineering is unavoidable. Galvanic corrosion and crevice corrosion are common corrosion forms of flanges, especially flange flanges due to water absorption and aging of flange gaskets, or pipeline corrosion. Due to the micro-deformation under force, cracks appear, which cause serious corrosion or even perforation of crevice corrosion-sensitive materials such as copper, titanium and stainless steel. Corrosion failure accidents of metal components occur frequently, which accelerates the damage and aging of metal materials, and brings negative impacts on the normal operation of ships. In the prior art, the solution to the problem of galvanic corrosion is mainly to implement electrical insulation measures between dissimilar metals. However, in the actual use of electrical insulation measures, the insulation state gradually deteriorates with the aging of insulating materials, and premature failure occurs. If the insulation effect is not good, galvanic corrosion will still occur, and it cannot isolate the galvanic corrosion current; to solve the problem of crevice corrosion, insulating sleeves and gaskets are used, and casings and gaskets made of different insulating materials are used Placed between dissimilar metal materials to isolate their contact and achieve insulation purposes. The insulating sleeves include glass fiber insulating sleeves, PVC sleeves, heat shrinkable sleeves, Teflon sleeves and ceramic sleeves, etc.; disclosed in Chinese patent 201310321466.7 An insulating sleeve includes an insulating tube, an umbrella shed coated on the insulating tube, a first flange and a second flange respectively connected to both ends of the insulating tube, and a conductor. The body is a column, and the conductor is directly connected to the first flange and closes the insulating tube together with the first flange; an insulating sleeve and an insulating tube disclosed in Chinese patent 201510490225.4, the insulating sleeve includes an insulator, and the insulator includes an intermediate The umbrella skirt and the lower flange connected to the lower end of the umbrella skirt, the head, including the oil conservator connected to the upper end of the insulator, and the terminal connected to the oil conservator, the tail, connected to the lower end of the insulator, the tail includes an insulating tube, and the insulation The tube is made of fiberglass, and the insulating tube is prepared by fiber winding and resin casting; an insulating tube and an insulating sleeve disclosed in Chinese patent 201510489210.6 include insulators, and the insulators include the middle shed part and the lower flange at the lower end of the shed part. The head is connected to the upper end of the insulator. The head includes the oil conservator connected to the upper end of the insulator and the terminal connected to the oil conservator. The insulating tube is connected to the lower flange. The insulating tube includes the upper transformer tube and the lower one. Oil-immersed tubes and transformer tubes include an inner tube and a conductive layer arranged outside the inner tube, and the conductive layer is grounded; however, the structure of the insulating sleeve is complex, and mismatches often occur during installation, resulting in conduction between dissimilar metals, which cannot be effective Solving Crevice Corrosion Problems

At present, there are no relevant reports and literatures on the design of insulating coating on the flange surface for direct anti-corrosion insulation