In many metal materials, in addition to stainless steel material is not easy to rust, other materials in the case of certain factors affected by the possibility of rust, stainless steel castings is also the case. For the quality of stainless steel castings, alkali etching must be done.
A dense oxide film is formed when the unprocessed side of the casting is not cooled. Due to the relatively short time of alkali etching, castings can not be thoroughly cleaned up, and the dissolution rate of cast aluminum parts is faster than that of alkali etching, which will cause excessive corrosion of cast aluminum parts.
In the process of stainless steel castings production, alkali corrosion treatment has become one of the essential links to effectively prevent the problems caused by the scrap of the workpiece. Stainless steel castings in the manufacturing process, in addition to the free silicon, there are a variety of compounds between the metal and other inclusions, but also because of casting aluminum parts of the cause of the formation of loose, so the chemical composition of uneven phenomena.