Stainless steel - Electro-polishing or electrolytic polishing

|Electro-polishing, to limit risk of adherence to the maximum

Electro-polishing is used to reduce the micro-roughness of a metal surface and thus limit the risk of adherence of external elements to the maximum.

 

|Electro-polishing, an anodic dissolution process

Electro-polishing is an anodic dissolution process normally used to remove a thin surface layer from a metallic material, due to a set of electrochemical reactions in a concentrated acid medium. The principle consists of immersing two metal electrodes in a solution (the electrolyte) between which an electric current is applied. The sample the surface of which is to be electro-polished is placed as an anode (positive electrode).  A reference electrode can be added to the other two in order to measure the voltages at their terminals.

Advantages of electro-polishing:

  • Surfaces of complex geometry can be treated, as well as hard materials.
  • Electro-polishing removes metallic inclusions and enables a new thin oxide layer to be formed which is homogenous and uniform and rich in chromium oxide.
  • The consequence of these surface changes is a clear improvement in resistance to corrosion, locally and generally.
  • Electro-polishing reduces the presence of surface defects and decreases roughness. Typical topography of an electro-polished surface consists of an evenly distributed group of "peaks and valleys”.

 

|Technochim – Large size electro-polishing baths

Technochim has a large size electro-polishing bath (7m x 2m x 2.5m). In addition it has its own know-how concerning the electrolyte’s chemical composition. Technochim has in fact developed an electrolyte that enables an extremely high brilliance of stainless steel to be obtained.

Technochim also has individual electro-polishing machines (portable rectifier or tampon electrolysis) in order to operate on its customers’ sites.