Heat-resistant anti-corrosion coatings protect against oxidation and corrosion of sulphides at high temperatures

China Coatings Online News Information
High temperature sulfur corrosion refers to the temperature above 240 degrees C, sulphides, monosulfur and other corrosion of equipment, and with the increase in temperature and aggravation. Long-term sulfur corrosion in the anti-corrosion coating research room found that sulfur corrosion at lower temperatures, on the metal surface formed FeS protective film, and when the temperature reached 200 degrees C, sulfur corrosion accelerated, 340-460 degrees C to the strongest degree, because sulfur The activity increases with the increase of the temperature, and its reactive type: Fe-S-FeS, and when the temperature rises to 375-430 degrees C, H2S can also react directly with iron, and its reactive Fe-H2S-FeS-H2.
in the process of high temperature sulfur pre-treatment, the increase of device treatment also has a significant effect on high temperature sulfur corrosion. A dense FeS protective film produced by high temperature sulfur corrosion on the metal surface has a certain protective effect on the equipment, which decreases the corrosion rate. Do a good job of corrosion in high temperature environment, anti-corrosion coating temperature can reach 800 degrees C, high temperature sulfur, sulphide corrosion, strength can reach 120Mpa, excellent corrosion resistance, high thermal conductivity, good heat transmission performance, high hardness, wear resistance Good, in a very good anti-corrosion environment to speed up heat transmission, this is anti-corrosion coatings, high-temperature anti-corrosion coatings using inorganic - organic modified grafting technology, solution resistance to high temperature, temperature resistance of 800 degrees C, heat transfer, weather resistance is good. Paint solid pigments using silicon carbide, passivated metal oxides, graphite and other good anti-acid and alkali materials, high-temperature sulfur, sulphide corrosion effect is good, sulfur-resistant strong oxidation and sulphide reduction, in addition to high-temperature anti-corrosion coating heat coefficient is high, infrared phase boundary temperature changes stable, good heat transmission, can be very good in the corrosion environment heat transmission, solve the problem of corrosion-resistant industrial equipment under the thermal. High temperature anti-corrosion coatings can be applied to sulfur and sulphide-related pipes, high-temperature synthesis, reactor, high-temperature anti-corrosion coatings can also be used in high-temperature chemical equipment, chimneys, high-temperature steam pipes, heat exchangers, high-temperature kilns, petroleum and petrochemical cracking equipment, engine components and exhaust pipes on high-temperature, thermal anti-corrosion. The excellent performance of thermal anti-corrosion coating ensures that the substation can be well protected, extend the service life of the substation, the paint performance is much larger than ordinary materials, the technical content reached the world's advanced level.
in addition to so3 dew point corrosion at low temperature, low temperature SO3 dew point corrosion of the process: H2S-O2-SO2-H2O-Q When excessive oxygen is present, there is the following reaction: SO2-O2-SO3-Q Q In the high temperature combustion furnace segment, SO3 does not corrode the equipment, but below 400 degrees C, high temperature anti-corrosion coating also has a very good anti-corrosion effect, SO3 and water vapor began to combine to produce thin sulfuric acid: SO3, H2O, H2SO4. When the amount of treatment increases, the flow rate increases, in the heat exchange tube, three-way, elbow and other places prone to turbulence and vortex, the surface protection film is easy to be washed off, exposing a new surface, start a new round of corrosion, so that the corrosion rate is greatly increased.
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