Electroplating, hot-dip galvanizing, and mechanical plating are the most common methods for the surface of fasteners. The process of forming a coating on the surface of fasteners. After surface treatment, the fasteners can present a more beautiful appearance. Appearance, the corrosion resistance of the fastener itself will also be improved. The main purpose is to obtain the anti-corrosion ability of the fastener itself, so as to increase the reliability and adaptability of the
fastener. Therefore, the quality judgment of the surface treatment of the fastener is mainly to check the anti-corrosion ability of the fastener. Whether the increase is effective, and whether the increase is in line with the expected requirements.
1. Electroplating of
fasteners
The electroplating of fasteners refers to immersing the part of the fastener that needs to be plated in a specific aqueous solution, and the aqueous solution will contain some deposited metal compounds, so that after passing the current through the aqueous solution, the metal substances in the solution are precipitated and adhered to. on the immersed portion of the fastener. The electroplating of fasteners generally includes zinc, copper, nickel, chromium, copper-nickel alloys, etc.
2. Hot dip galvanizing of fasteners
The hot-dip galvanizing of
fasteners is to immerse the fasteners made of carbon steel into a molten zinc plating bath with a heat of about 510 ° C, so that the iron-zinc alloy on the surface of the fasteners will be converted into passive zinc, thereby Get a surface finish. The price of hot-dip galvanized fasteners is higher than that of electroplating, about 1.5 to 2 yuan per kilogram.
3. Mechanical plating of fasteners
The mechanical plating of
fasteners refers to impacting the surface of fasteners with the powder of plated metal through specific physical and chemical means, so that the plated metal forms a coating on the surface of the fastener through cold welding to reach the surface of the fastener. processing effect. Mechanical plating of fasteners is mainly suitable for spare parts such as screws, nuts and washers.
