As we all know, stainless steel
screws are the original color. In most cases, surface treatment is not required unless required by customers. Some customers have mentioned before that stainless steel screws change color during application, reddening or blackening. So, what is the reason for the discoloration of stainless steel screws?
1. The discoloration of stainless steel plate is generally caused by the fact that the screws are not cleaned and tidy during the cleaning process after hardening treatment, and the cleaning solution is still left on the surface of stainless steel screws. Therefore, after being used for a period of time, the cleaning solution produces chemical changes with it, resulting in the discoloration of the surface of stainless steel screws.
2. There is also the red rust caused by the phosphating treatment film on the surface of stainless steel
screws after quenching and tempering. In order to prevent the discoloration of screws, we will remove the phosphating treatment film before the heat treatment process. In the process of heat treatment, we should appropriately raise the maturity of mesh belt furnace area.
3. After the stainless steel screw is quenched, the water quenching material remaining in the stainless steel
screw can easily reduce the rust prevention characteristics of the stainless steel screw and blacken after being used for a period of time. In the process of application, we should check the data information of the water quenching material every three or five times, so as to prevent the blackening of the surface of the stainless steel screw.
4. In the process of stainless steel screw quenching, if the oil is excessively aged, it may also cause the
screw to turn black. In the process of selecting oil quenching, the temperature should be generally reduced, generally 50 degrees is more suitable, which can ensure that the rate of oil aging can be reduced.
