Fasteners are small, but they have a huge role. As an important mechanical part for fastening, it is necessary to perform regular maintenance. In this way, fasteners can play a better role in performance, use more safely, and prolong their service life. Improve the use of mechanical equipment. In order to prevent some problems with fasteners, the following points must be taken into account when carrying out routine maintenance of fasteners.
1. When the fastener is quenched, use silicate cleaning agent to clean the above impurities, and then carefully rinse to avoid leaving impurities on the fastener, affecting its normal application.
2. After the fasteners are tempered, there may be signs of discoloration. After the fasteners are soaked in ether for a period of time, there will be oily substances. This will indicate that the fasteners are not clean enough. . After the analysis was performed, it was known that the fasteners were stacked improperly when heated, resulting in slight oxidation of the fasteners in the quench oil.
3. If there is a white substance on the fastener, it is likely to be some phosphide. The reason for this phenomenon is due to the fact that the acid cleaner was not used for cleaning, and the rinsing tank inspection was not thorough.
4, high-strength screws quenching heat black with a uniform, smooth oil black outer surface. After testing for alkaline burns. Therefore, the steel fasteners cannot remove the surface alkaline substances in the quenching oil, thereby causing the surface to burn at a high temperature and aggravating the damage during tempering. It is recommended that the fastener be thoroughly cleaned and rinsed before heat treatment to completely remove the alkaline residue that causes the fastener to burn.
5. For large size fasteners, quenching with aqueous polymer solution is often used. Before quenching, it is cleaned and rinsed with an alkaline cleaner. After quenching, the fasteners are rusted on the inside. Therefore, it is necessary to exchange the rinsing water frequently to ensure that the fastener does not rust during rinsing.
6, high-strength fasteners often see some black stripes, the black stripes for the residue of the surface of the contaminants, baked oil for quenching, is the evolution of the gas phase in the quenching process. Because of the excessive aging of the quench oil, it is recommended to add new oil.
The above problems must be paid attention to, because it will directly affect the performance of fasteners, it may also lead to shorten the service life of the fasteners, resulting in early damage of the fasteners