In order to improve the wear resistance and corrosion resistance of barite mill, and to play a decorative role, the surface coating technology based on metal material coloring technology has been widely used. The following is a description of the coloring of commonly used steel parts.

Under natural conditions, steel parts form an oxide film on the surface due to contact with oxygen in the air. Naturally, when forming a film, depending on the physical properties of the metal itself, the surface state and the oxidation conditions, the oxide film formed is thin, some is dense and complete, and some are loose and incomplete.

An oxide film which is dense and complete and has a certain mechanical strength on the surface of steel can be chemically or electrochemically. There are many oxidation treatment methods for steel, such as alkaline oxidation, alkali-free oxidation, high-temperature gas oxidation, and electrolytic oxidation.