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Polishing Methods for Duplex Steel Flanges
1. The polishing methods of dual-phase steel flanges are manual, mechanical, chemical and electrochemical. The corrosion resistance and decoration of the flange can be improved by polishing. The existing stainless steel electropolishing solution still uses phosphoric acid and chromic anhydride. During the polishing and cleaning process, some chromium and phosphorus will be discharged into the waste water. pollution of the environment.
2. A passive film will be formed on the surface of the dual-phase steel flange, and the oxide film will begin to dissolve. Because the surface of the dual-phase steel flange is microscopically inconsistent, the microconvex part on the surface dissolves preferentially, and the dissolution rate will be greater than that of the concave part. The film dissolves and forms at almost the same time, but its speed is different. As a result, the surface roughness of the duplex steel flange is reduced, resulting in a smooth, shiny surface.
3. By polishing, some surface defects such as surface pores and scratches can be filled, thereby improving fatigue resistance and related corrosion resistance. The yield strength of duplex steel flanges is more than double that of austenitic stainless steel, and it has sufficient plasticity and toughness for this forming, as well as excellent resistance to stress corrosion cracking, especially in chloride ion environments.
Duplex Steel Flanges,polishing
The shielding gas pressure of the butt welding flange is to avoid slight leakage of the butt welding flange. The shielding gas in the furnace should be connected to a certain positive pressure. Assuming that it is hydrogen shielding gas, it is generally required to be above 20kBar.
Welding spatter, iron filings, grease and other external impurities should be removed from the moving area of the probe. The flaw detection cousin should be flat and smooth to facilitate the free scanning of the probe. The surface roughness R.<6.3μm should be ground if necessary.
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No.27 Gangqiang Road,Konggang Economic Zone,Yongxing Street,Longwan District,Wenzhou,China