Electrolytic polishing of stainless steel is a technology that uses electrochemical methods to improve surface finish and remove rough surfaces. This treatment method can not only improve the appearance of stainless steel, but also enhance its corrosion resistance and wear resistance.
Author: Marisa
Electrolytic polishing of stainless steel is a technology that uses electrochemical methods to improve surface finish and remove rough surfaces. This treatment method can not only improve the appearance of stainless steel, but also enhance its corrosion resistance and wear resistance.
The following are the detailed steps and key points for electrolytic polishing of stainless steel:
1. Preparation
Material selection: Make sure to use stainless steel materials suitable for electrolytic polishing. Common grades include 304, 316, etc.
Surface pretreatment: Before electrolytic polishing, the surface must be thoroughly cleaned and degreased, rusted, and other contaminants removed. Solvent cleaning, alkaline cleaning, or pickling are usually used.
2. Selection of electrolyte
Electrolyte composition: The electrolyte is usually composed of sulfuric acid, phosphoric acid, water, and a small amount of additives. Sulfuric acid and phosphoric acid are the main electrolytes, which can provide the necessary chemical environment for the redox reaction on the metal surface.
Concentration and temperature: The concentration and temperature of the electrolyte are key parameters. Generally, the ratio of sulfuric acid to phosphoric acid is 2:1, and the electrolyte temperature is controlled between 50-70°C.
3. Equipment setup
Electrolytic cell: The electrolytic cell should be made of acid-resistant materials such as polypropylene or fiberglass.
Anode and cathode: The stainless steel workpiece is used as the anode, and an inert electrode (such as lead or graphite) is used as the cathode.
Power supply: A DC power supply is used, and the voltage and current density need to be adjusted according to the specific processing requirements. Usually the voltage is 10-25V and the current density is 10-50A/dm².
4. Electrolytic polishing process
Hanging the workpiece: Hang the stainless steel workpiece in the electrolytic tank to ensure that the workpiece is completely immersed in the electrolyte and is not touched by other workpieces.
Power-on treatment: Turn on the power supply and start electrolytic polishing. During the electrolysis process, an oxidation reaction will occur on the surface of the anode (stainless steel workpiece), forming a thin oxide film, which will be evenly dissolved under the action of the electrolyte, thereby achieving the polishing effect.
Time control: The electrolytic polishing time is usually 3-15 minutes, depending on the initial state of the workpiece and the required polishing effect.
5. Post-processing
Cleaning: After the electrolytic polishing is completed, the workpiece is immediately cleaned thoroughly with clean water to remove the residual electrolyte.
Neutralization treatment: Sometimes it is necessary to use a dilute alkali solution to neutralize the acidic residue on the surface of the workpiece.
Drying: Finally, the workpiece is thoroughly dried to prevent water stains and secondary contamination.
6. Quality inspection
Surface quality: Check whether the polished surface is smooth and uniform, without scratches, spots and other defects.
Corrosion resistance: Evaluate the corrosion resistance of polished stainless steel through salt spray test or other corrosion tests.
Through the above steps, the electrolytic polishing of stainless steel can effectively improve the surface finish and corrosion resistance, and is suitable for a variety of industrial and decorative applications. In the whole process, the selection of electrolyte, temperature control, time management and post-processing steps are key factors to ensure the polishing effect.