Reasons for color difference in stainless steel wire mesh after welding

Why do stainless steel wire meshes exhibit color variations after sandblasting or welding? Stainless steel wire mesh is used for screening and filtration in acidic and alkaline environments. In the petroleum industry, it's primarily used for mud filtration; in the chemical fiber industry, it's used for screening and electroplating. The stainless steel wire mesh can partially melt or melt another part of the product, bonding two or more unrelated components together, causing discoloration due to high temperatures. For aesthetic reasons, overall pickling and polishing after finishing is recommended.
A passivation film forms on the surface of the stainless steel wire mesh, which essentially exists in the form of more stable oxides. It can be said that stainless steel mesh will eventually oxidize, but the degree of oxidation varies depending on the usage conditions. This phenomenon is called corrosion. Dust on the surface of stainless steel wire mesh is easily removed. It can be cleaned with soap, mild detergent, or warm water.
The surface of stainless steel wire mesh should first be rinsed with water using bleach and various acidic additives, then immersed in a neutral sodium carbonate solution or ammonia solution, and then rinsed with warm water or neutral detergent during the preparation of the stainless steel wire mesh. This is because it requires processes such as drawing, full diameter, and weaving.
During the processing of stainless steel wire mesh, some oil or dirt inevitably adheres to its surface. This necessitates surface cleaning and descaling to improve its appearance and quality. Oil, grease, and lubricants on the stainless steel wire mesh surface should first be cleaned with a soft cloth, followed by cleaning with ammonia, a specialized cleaner, or a neutral detergent.