No matter what products will have some unqualified defective, stainless steel flange is the same, stainless steel flange in the process of processing due to improper operation, or because of the assembly line machinery out of the small problems, resulting in the production of flange defects, common is serious weld defects. In the face of such products, there will be no customer demand, so the manufacturer will carry out "secondary processing" to deal with this batch of defective flanges.
First, use machine grinding.This is a commonly used method, but it produces obvious grinding marks, resulting in uneven surface (this is not the case with more advanced equipment), which will affect the aesthetics and is not conducive to being recognized and accepted by customers.
Second, use manual polishing.After manual polishing, pickling and passivation treatment is carried out. It is difficult to achieve uniform and uniform treatment effect for the workpiece with large area, and the ideal uniform surface cannot be obtained. Still have its drawback to have man-hour cost, accessory cost is higher also.
Third, adopt sulfuric acid "clean".Generally, the first use of sulfuric acid cleaning, and then manual polishing of stainless steel flange, the overall pickling passivation, in the presence of corrosive medium conditions will occur chemical corrosion or electrochemical corrosion and rust, can not remove due to scratch, welding splash and adhere to the surface of stainless steel carbon steel, splash and other impurities.