Why does stainless steel turn yellow when marked with a UV laser marking machine?

The reason why the UV laser marking machine turns yellow when marking stainless steel may be related to its working principle and the characteristics of the stainless steel material. First of all, the working principle of the UV laser marking machine is to irradiate the surface of the material with a high-energy laser beam, causing the material to quickly melt, vaporize or reach the ignition point. At the same time, it is filled at a certain speed to form fine, beautiful and easily identifiable text.

and patterns. However, during the laser marking process, the stainless steel material may be affected by the high energy of the laser beam, causing its surface to be oxidized, discolored or scorched, resulting in yellowing.

In addition, stainless steel is a highly reflective metal material, which may reflect part of the laser beam during the laser marking process, causing the energy distribution of the laser beam to change. This change may cause the heat-affected zone of the laser beam on the stainless steel material to become larger, causing the stainless steel material near the heat-affected zone to oxidize, discolor or burn, further leading to yellowing.

In addition, the thickness of the stainless steel material and the power of the laser beam may also be factors affecting the yellowing phenomenon. If the thickness of the stainless steel material is too large or the power of the laser beam is too high, it may cause the stainless steel material to be overheated during the laser marking process, resulting in yellowing.

In summary, there are many reasons for the yellowing phenomenon when UV laser marking machines mark stainless steel, including the working principle of the laser marking machine, the characteristics of the stainless steel material, and the parameter settings of the laser beam. In order to reduce the occurrence of yellowing, you can try to improve it by adjusting the parameters of the laser beam, selecting appropriate stainless steel materials, and optimizing the process parameters of the laser marking machine.