Why is the screw chrome plated

Does double alloy screw need chrome plated

Chrome-plated treatment is mainly for anticorrosion, according to the production of different materials and the double alloy screw is required to be plated with chromium corrosion. The chromium plating layer has good chemical stability, which is not effective in alkali, sulphide, nitric acid and most organic acids, but can be soluble in hydrogen halide, such as the sulfuric acid which is free of heat of hydrochloric acid. The screw chrome can be anti-rust, anticorrosive, improve surface hardness, decorative effect, appearance also good-looking.

Double - alloy screw has to be chrome plated

Chromium plating is a kind of chromium plating. There are two methods for chrome plating. The first one is chrome plating, and the second is hard chromium plating. Electroplating hard chromium is a better method to increase surface hardness. This method has many advantages, so it is not used in most cases.

Double - alloy screw has the advantages of chromium plating

The advantage is, the surface is clean good, the advantage two, does not rust, a little rust spot does not have; 3. The original parts in the process of plating are small. 4. If the part size is not in place, you can achieve the size by adding a few silk chrome. In the visible range, chromium has a reflective capacity of about 65 per cent, between silver (88%) and nickel (55%), and is not discolored due to chromium, which can be used for a long time to retain its reflective ability rather than silver and nickel.

Chrome-plated manufacturing process

The main component of chrome-plating solution is not metal chromate, but chromic acid - chromic acid, which is a strong acid plating solution. Electroplating process, the complex cathode process, most of cathodic current consumption in hydrogen evolution and hexavalent chromium to trivalent chromium on the two side effects, screw barrel plating chromium cathode current efficiency is very low (10% ~ l8 (%). There are three abnormal phenomena: the current efficiency decreases with the increase of chromic anhydride concentration and the temperature decreases with the increase of temperature. The increase of current density increases.