Duplex steel flange commonly used methods of polishing

- Feb 06, 2018-

In order to improve corrosion resistance and decorative dual-phase steel flange, it needs to be surface polished. Currently polishing methods are manual, mechanical, chemical and electrochemical four. The existing stainless steel electro-polishing liquid still uses phosphoric acid and chromic anhydride. During the polishing and cleaning process, some chromium and phosphorus will be discharged into the waste water and pollute the environment.(welding overlay,flange,pipe spooling)


Duplex steel flange surface formation of passive film, while the oxide film dissolved, the former is stronger than the latter. Due to the microscopic inconsistencies on the surface of duplex steel flanges, the surface of the microprojections is preferentially dissolved and the rate of dissolution is greater than that of the depressions. The dissolution and formation of the membranes are almost at the same time but at different velocities.(welding overlay,flange,pipe spooling)


As a result, dual-phase steel flange surface roughness becomes lower, to obtain a smooth, shiny surface. Polishing can fill the surface pores, scratches and other surface defects, thereby improving the fatigue resistance, corrosion resistance. Dual-phase steel flange yield strength than ordinary austenitic stainless steel more than double, but also the molding of the required plasticity and toughness; the other dual-phase steel flange has excellent resistance to stress corrosion cracking, especially in the chloride ion Environment; super duplex steel with high corrosion resistance, in some media, acetic acid, formic acid or even higher can replace high-alloy austenitic stainless steel, and even corrosion-resistant alloys.(welding overlay,flange,pipe spooling)