The use of fasteners should pay attention to details, performance is very key, regular maintenance is the key, to ensure the normal operation of the machinery. In order to prevent some problems with fasteners, we must pay attention to the following key points when conducting daily maintenance of fasteners.
1.The pollution caused by rinsing.
Fasteners need to be cleaned with silicate detergent after quenching, and then rinsed, so they should be washed very carefully to prevent residues.
2.The fastener stacking is unreasonable.
After tempering, the fastener will show signs of discoloration, and there may be oily residues after soaking in the ether, indicating that the surface of the fastener is not clean. After the analysis, the fasteners are not stacked properly when heating, resulting in a slight oxidation of the fasteners in the quenching oil.
3.Surface residues.
There were white residues on the high strength screws, which were analyzed by instruments and confirmed as phosphate. This reaction occurred because the acid washer was not cleaned and the rinsing tank was not thoroughly checked.
4.Alkali burn.
High strength screw quenching waste heat black has a uniform, flat oil black outer surface. It is caused by alkali burn. Therefore, the steel fasteners can not remove the surface alkaline in the quenching oil, which causes the surface burns at high temperature, and increases the damage during tempering. It is recommended to thoroughly clean and rinse the fasteners before heat treatment, to completely remove the alkaline residue that causes burns to the fasteners.
5.Improper rinsing.
For large specifications, the fasteners are often used by quenching with polymer aqueous solution, and they are cleaned and rinsed with an alkaline cleaning machine before quenching, and the fasteners have rusted on the inside after quenching. So often exchange rinse water, to ensure that the fasteners will not rust.
6. Excessive rust.
High-strength fasteners often see some black stripes, this black stripes for the surface residual contaminants, for the baked dry quenching oil, is the evolution of the gas phase in the quenching process. Because it is quenching oil excessive aging, it is recommended to add new oil.
Post time: Aug-19-2022