the coating corrosion or oxidation in the environment, closed is a content of coating design must be considered. Any kind of thermal spraying coating method, there is porosity. With flame spray coating porosity, among them the most. In general, the coating porosity range is quite large. Flame spray coating porosity sometimes as high as 15% above, and high-speed oxygen - gas spray (HVOF) layer is below 1%. Table 2 is made of different thermal spraying coating porosity. As hot spraying anti-corrosion coating, is the most widely used electric arc spraying and flame spraying process, by can be seen in table 2 of these two kinds of coating porosity is relatively high, so in some circumstances coating closed processing is very necessary. In practice, although sometimes in the coating porosity is advantageous, however, in more cases, the porosity of the coating is not hope.
In many corrosive environment spraying metal anode sex coating on steel substrate are longer than traditional coatings to protect life. Reasonable coating design can obtain the most economic and effective protection. Reasonable coating design from the preliminary work environment protection components, influence factors and the result of careful analysis and study of the design life. Economic factors, of course, is also one of the most important content. For a specific project artifacts can choose anticorrosion scheme may have many kinds, therefore, the design requirement to the advantages and limitations of various methods have a wide range of understanding. Environmental protection, construction period and the maintenance methods are needed in the future into consideration.
At present, for large steel structure imposed by the thermal spraying anti-corrosion coating for zinc, aluminum, or their alloys. So which kind of material is more suitable? Above all, want to clear the work to protect the components under what conditions, if it is in the atmospheric conditions, it belongs to which kind of atmospheric conditions? Rural atmosphere, industrial atmosphere, or Marine atmosphere. If it is under the condition of industrial application, consider the working temperature, pH value of artifacts, exposure to chemical corrosion.
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