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Fasteners are common components in mechanical equipment and play a crucial role. However, corrosion of fasteners during use is a common cause of damage. In order to prevent corrosion of fasteners during use, surface anti-corrosion treatment is essential.

There are various methods for surface anti-corrosion treatment, such as spray painting, cold galvanizing, alloy catalytic liquid, and so on. And among them, the degree of corrosion resistance varies depending on the production process. Next, we will introduce the process steps and characteristics of spray painting treatment, cold galvanizing, and alloy catalytic solution in sequence.

1. Painting treatment

Process: The surface is first degreased, pickled, phosphated, passivated, or pre treated with a shot blasting machine for surface slag and rust removal. After that, an anti rust primer is sprayed once, and then a magnetic topcoat is sprayed for surface protection treatment.

Features: Uniform and consistent color; Sense of solidity; Excellent anti-corrosion performance. However, non professional manufacturers only consider winning bids at low prices and often do not undergo phosphating or shot blasting pre-treatment. They directly spray paint, which has a short anti-corrosion time and poor effectiveness; Alternatively, using small factories to produce inferior paint can reduce costs, as harmful substances are difficult to disperse and may have an odor for a certain period of time.

2. Cold galvanizing

Process: Using electrolytic equipment, the pipe fittings are degreased and pickled before being placed in a solution containing zinc salts. The negative electrode of the electrolytic equipment is connected, and a zinc plate is placed opposite the pipe fittings. The positive electrode of the electrolytic equipment is connected to the power supply, and a layer of zinc is deposited on the pipe fittings by directional movement of the current from the positive electrode to the negative electrode. Cold plated pipe fittings are processed first and then galvanized.

Features: Strong metallic color; Cold galvanized coating can be used for welding operations without affecting welding quality; Good anti-corrosion performance. However, the zinc powder content in cold galvanized paint is high, and thick coating construction is not recommended as it is prone to cracking of the paint film; The surface of the cold galvanized paint coating is a porous structure, which will leave air residue. Therefore, the topcoat or intermediate coat is prone to air bubbles.

3. Alloy catalytic liquid

Process: Put the blank into a 2-in-1 purification solution and soak for 2-10 minutes. After pre-treatment, clean the workpiece in clean water. Then, soak the cleaned workpiece in an alloy catalytic solution heated to 85 degrees Celsius for 10-20 minutes, which can be adjusted according to different product processing requirements. After washing with water, the finished product is made.

Features: The alloy catalytic liquid has a high bonding strength with the workpiece, strong corrosion resistance, and is not easy to peel or peel off. It not only maintains the original mechanical properties of the workpiece, but also increases wear resistance and corrosion resistance; The processed workpiece does not have excessive thickening at sharp corners or protruding edges, so there is basically no need for secondary grinding processing; No matter how complex the shape of the surface is, it can undergo surface treatment with almost no pitting or porosity.