Iron and steel in the condition of cooling on the surface galvanized, and hot dip galvanized steel pipe in the condition of hot dip on the surface, its adhesion is strong, not easy to fall off, hot dip galvanized pipe although also rust phenomenon, but in a long period can meet the technical and sanitary requirements.

1. Adjust electroplating process parameters

Large roll galvanized wire phosphating film is dark gray to black gray, the thickness is generally 5-20μm, has better corrosion resistance in the atmosphere. Membrane is a microporous structure, strong adsorption ability to paint, such as used as paint bottom, corrosion resistance can be further advanced. Metal oxidation treatment: Add steel products to NaOH and NaNO2 mixed solution, heating treatment, the surface can form a layer of thickness of about 0.5-1.5μm blue oxide film, in order to reach the purpose of steel corrosion prevention, this process is called blue treatment, referred to as blue.