Higher requirements are put forward for the material, functionality, anti-corrosion and even decoration of the various parts of machinery and equipment. The comprehensive performance of the coupling rough parts and finished parts puts forward higher requirements, especially the continuous progress and improvement in the surface anti-rust process of iron parts, from the original spray paint, alkaline blackening liquid to the current Blackening process at room temperature. Due to the need for protection, the original method of painting on castings is no longer popular, and the paint will cover up cracks, pores, and paint drop on the castings.
The alkaline blackening liquid used has low efficiency and high energy consumption, especially when dealing with cast iron, it is easy to appear khaki, and the appearance is often not satisfied with the customer, and it is blackened at room temperature. Coupling castings due to the particularity of the manufacturing process, the surface of the casting is easy to rust, and it is difficult to handle after rust. If it is not paid attention to, not only the anti-corrosion ability of the workpiece is poor, but the decoration is not good. While putting forward higher requirements for corrosion resistance, according to the different working conditions of the castings, the castings (cast iron, cast steel) are required to be blackened at room temperature, phosphating treatment and other special anti-rust treatments.
The difference between iron castings and other steel parts is that the structure is loose and the carbon content is high. If improperly handled, it will directly affect the bonding strength of the blackened film and the matrix. Therefore, pretreatment is particularly important. The room temperature blackening process of coupling cast iron parts is a lower cost and simpler operation method for the blackening surface treatment of the casting parts. This process can give the cast iron parts a pure and elegant black appearance and improve the rust resistance of the cast iron parts. Thereby enhancing the value of the product. Therefore, we believe that this process can be widely used in cast iron anticorrosion treatment, and at the same time, it will continue to improve and innovate in production practice.
