How are the stamped parts protected against corrosion?
source：未知 Writer： hmdmould Time：2021-04-27 10:52 Browse：
The application of metal stamping parts in our daily life is more and more common, but the requirement of metal stamping parts is also higher and higher. The corrosion resistance of metal stamping parts is one of them.
At present, although the service life of metal stamping parts meets the industry standard, the service life of most metal stamping parts can reach more than 15,000 times, and the neutral salt spray test test standard is 96 hours. In theory, they should last more than 10 years. However, the hardware fittings that regards door window accessory as has mechanical property not only, and still have certain adornment function. Like discoloration and rough profiles, users can't accept them. Rough, rusty, and faded hardware is undesirable. It is imperative to improve the corrosion resistance of metal stamping parts. Carbon steel is widely used in transmission lock, lining steel and other carbon steel stamping parts. How to improve its corrosion resistance is the key to its service life. Due to frequent exposure to rain and sunshine, the surface of Shanghai's PVC profile was severely corroded after less than three years of use. According to the relevant data, it can be seen that under the action of light and heat in the aging process, hydrogen chloride will be released on the surface of the PVC profile, which has a strong corrosive effect on the galvanized layer, which can explain why the surface of the PVC profile will be corroded. According to the relevant British standards, the corrosion of PVC profiles is very serious, in addition to 96 hours of neutral salt spray test, the thickness of the galvanized layer is not less than 40 meters, the current domestic standards only consider the time of salt spray test, and did not consider the thickness of the coating. If the passivation film is complete and the performance is good, the 10m coating can pass the 96-hour neutral salt spray test. Once the passivating film is damaged, it is easy to rust. The domestic electroplating industry generally believes that the 96-hour salt spray test is only a test of the protective performance of galvanized passivation film. In addition, according to the requirements of the use of the environment, the thickness of the galvanized layer can be divided into three grades: good environment, general environment and bad environment. The thickness of the galvanized layer is 61m, 121m and 24m respectively. Therefore, the metal stamping parts in the production process also need to be treated with anti-corrosion, in order to effectively avoid corrosion in the process of use. The main methods are: 11. Preheating the stamping parts before spraying can improve the adhesion of asphalt coating and accelerate the drying. Specially coated cement mortar lining can improve the corrosion resistance of the stamping parts.
Epoxy coal tar coating for metal stamping parts is a two component coating with high adhesion and smooth surface. Due to the difficult manufacturing process and high cost, epoxy ceramic lining has some limitations in use. With good adhesion and finish, it is an excellent anticorrosive coating for stamping parts. Aluminate cement coating or sulfate cement coating, these two special cement coating is suitable for the internal corrosion resistance of stamping parts, improve the corrosion resistance. Polyurethane coating is a new kind of green special coating developed to meet the requirements of environmental protection. It has good wear resistance and corrosion resistance.