Anti-high yin peeling: the research highlight of epoxy powder

China Coatings Online News Information: The research
anti-high temperature cathode stripping anti-corrosion epoxy powder coating is becoming a bright spot in the industry. The joint application of cathode protection and anti-corrosion layer is a technology commonly used in anti-corrosion of buried steel pipes, which has been applied in tens of thousands of kilometers of pipelines in China, and has achieved remarkable results. After long-term experience and technological progress, Sichuan gas east transmission engineering design on the epoxy powder coating performance indicators put forward higher requirements, such as: -1.5V voltage, 60 degrees C NaCl solution immersion 30d, cathode stripping radius ≤15mm. Through the analysis of the effect of cathode stripping on the coating, the powder coating of anti-high temperature cathode stripping was made by using the self-synthetic Amandall68 line-shaped three-function epoxy resin and Amanda999B interoperability network compound curing agent and auxiliary nano-silicon material, and the test results showed that the technical requirements of Sichuan gas east transmission engineering were reached. The corrosion-resistant layer of the pipe is not absolutely guaranteed to be free of any damage (coating at the filling port, coating density, coating pinholes, etc.) during production, transportation and construction, so it is not possible to completely isolate the pipe from the corrosive environment. And the various materials used for anti-corrosion insulation, to varying degrees, have absorbent and breathable, so after burying the ground will gradually absorb water. To maintain effective corrosion protection, cathode protection, i.e. joint protection, is necessary at the same time.
application of cathode protection and anti-corrosion layers can provide the most economical and effective protection for underground or underwater metal structures. Protective coatings are usually applied before use in order to isolate metal from dielectric ambient electrical insulation, and a good anti-corrosion layer protects more than 99% of the outer surface of the structure from corrosion.
China Coatings Online

Experts
recommend that when the pipe is jointly protected, the protective dosage (thickness >1mm) should be selected for the protective position of -1.10 to -1.15V (CSE) and the protective position of the thin coating (thickness ≤1mm) should be taken for the protective position of -1.05 to -1.10V (CSE). At the same time, consider the soil composition, humidity, temperature, coating type, application quality and microorganisms, etc. , appropriate adjustment of protection may be made. Protects pipes from damaging corrosion-resistant coatings. It is more effective to evaluate corrosion in different environments by polarizing current. Recently, Daqing Development Zone Qinglu Fine Chemical Co., Ltd., the coating cathode stripping test. Coating cathode stripping has a destructive effect on the coating, how to select the best protection potential in the operation of the actual buried steel pipe, cathode protection anti-corrosion layer (3PE anti-corrosion layer, the bottom layer is the melting epoxy powder) shedding reasons worth exploring. And the optimal protection of the position, cathode over-protection led to the corrosion layer shedding, improve the epoxy anti-corrosion powder coating anti-high temperature cathode stripping, anti-high temperature cathode peeling epoxy anti-corrosion powder coating was studied.
preparation and testing of applied test parts in the laboratory conforms to the following regulations: the test plate should be low carbon steel, the test surface should be sprayed and cleaned, and its rust removal quality should meet the requirements of GB/T 8923-1988 Sa 2.5, the surface anchor depth should be in the range of 40 to 100 m, the curing temperature of the coating applied should be 200 degrees C, the total thickness of the coating should be 200 to 300 m. High temperature, long-term coating cathode stripping test is a destructive test of the coating, the degree of coating cathode stripping radius, is the coating's impermeability, adhesion size, heat resistance, density and other indicators in the case of applied current comprehensive investigation and evaluation; Amandall68 line epoxy synthetic resin, and Amanda999B inter-transmission network composite curing agent, auxiliary nano-silicon material, made of anti-high temperature cathode peeling powder coating, the test results reached the technical requirements of Sichuan gas east transmission engineering. Regarding the cathode-resistant peeling test of the coating, a test piece with no leakage points should be used, the minimum leakage voltage of the electric spark leak detector should be 1800V; Inject at least 300mL of NaCl solution and mark the liquid position on the barrel, apply voltage to the test piece (apply voltage to the glycemic reference electrode) and keep the temperature constant under one or more of the following test conditions, remove the electrolyte at the end of the above test cycle and remove the test piece and cool it in the air to (20±3) degrees C.
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