Electropolishing is actually a method of polishing metal surfaces by electrochemical anodic dissolution. There are many factors that affect the electrochemical polishing of stainless steel, but the following are the main points.
1. electrolyte composition
According to the difference of polishing materials, the composition and density of the electrolyte used are different, and the polishing parameters are also different.
2. current density
The influence of current density on the surface leveling speed and the amount of metal dissolution is obvious. If the processing time is the same, the surface leveling and the metal dissolving speed are faster when the current density is large. The relative leveling rate in the uneven area (the ratio of uneven height before and after polishing) is independent of the current density when the same quantity of electricity is at the same time.
3. metallographic structure and original surface
Electrochemical polishing is very sensitive to the uniformity of metallurgical structure. The more homogeneous and fine metallographic structure of the metal, the better its polishing effect. If the metal exists in alloy form, the electrolyte with homogeneous alloy composition should be selected.
4. temperature and agitation
The temperature of electrolyte has great influence on the viscosity of the solution and the properties and composition of the anode film. The higher the temperature is, the faster the leveling speed is. When the temperature increased from 30 to 70, the dissolution rate of the metal almost increased by 1.5 times. For example, when the current density is 0.5A/cm, the electrolytic polishing time is 10min, the most suitable temperature is 100 C, but in order not to make the solution boil, it is generally about 70 C.
In electrolytic polishing, the electrolyte should be stirred as much as possible, which can not only promote the flow of the electrolyte, but also guarantee the ion diffusion of the polishing area and the supplement of the new electrolyte, and reduce the temperature difference of the electrolysis, thus ensuring the most suitable polishing condition.