Metal expansion joint inner surface FEP electrostatic powder spraying process

Abstract

The invention discloses a metal expansion joint inner surface FEP electrostatic powder spraying process in the technical field of spraying processes. The process comprises the steps of (S1) substrate selection, (S2) polishing, (S3) high-temperature oil removal, (S4) sand blasting and cleaning, (S5) spraying material preparation, (S6) preheating, (S7) primer spraying and drying, (S8) finish coat spraying, (S9) high-temperature sintering, (S10) repeated spraying and sintering, (S11) detection and treatment and (S12) cleaning and packing; Teflon paint of fluorine paint with polytetrafluoroethylene as basal body resins is adopted, so that the excellent characteristics of metal expansion joints are improved, the service life of the metal expansion joints is prolonged, the paint spraying operation is simple, and the paint spraying is uniform; through previous polishing, high-temperature oil removal, sand blasting and cleaning, impurities and dust on the inner surfaces of the metal expansion joints are effectively removed, so that the sand blasting roughness is improved; and through later finished product appearance detection, coating film thickness detection, electrospark detection and adhesion detection, the inner surfaces of the metal expansion joints thickly sprayed are detected by multiple times, so that the coating quality is improved.

Description

technical field [0001] The invention relates to the technical field of spraying technology, in particular to an FEP electrostatic powder spraying process on the inner surface of a metal expansion joint. Background technique [0002] In practical application, the metal expansion joint is a kind of flexible structure arranged on the container shell or pipeline to compensate the additional stress caused by temperature difference and mechanical vibration; Reliable, good performance, compact structure and other advantages; metal expansion joints can be divided into elbow expansion joints, bellows expansion joints and casing expansion joints. [0003] The high-temperature exhaust of the gas turbine will have a great impact on the metal expansion joints in the flue and exhaust system. If frequent washing is added, the life of ordinary metal expansion joints will be greatly affected. Once the expansion joints rupture, it will cause high temperature The leakage of flue gas not only ...

AI Technical Summary

Problems solved by technology

At present, metal expansion joints after spraying are prone to drumming and falling off. The main reasons are: 1. Poor pre-treatment, resulting in incomplete removal of impurities and residual dust; 2. Insufficient sandblasting roughness; 3. Uneven sintering temperature 4. Wrong selection of spraying materials; 5. Incomplete post-testing, which seriously affects the service life of metal expansion joints.

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