Analysis and Solutions to Common Issues in Electrolytic Polishing

1.Why are there spots or small areas on the surface that appear unpolished after electro-polishing?

Analysis: Incomplete oil removal before polishing, resulting in residual oil traces on the surface.

2.Why do gray-black patches appear on the surface after polishing?

Analysis: Incomplete removal of oxidation scale; localized presence of oxidation scale.
Solution: Increase the intensity of oxidation scale removal.

3.What causes corrosion at the edges and tips of the workpiece after polishing?

Analysis: Excessive current or high electrolyte temperature at the edges and tips, prolonged polishing time leading to excessive dissolution.
Solution: Adjust current density or solution temperature, shorten the time. Check electrode positioning, use shielding at edges.

4.Why does the workpiece surface appear dull and gray after polishing?

Analysis: Electrochemical polishing solution is ineffective or not significantly active.
Solution: Check if the electrolytic polishing solution has been used for too long, quality has degraded, or if the solution composition is imbalanced.

5.Why are there white streaks on the surface after polishing?

Analysis: Solution density is too high, liquid is too thick, relative density exceeds 1.82.
Solution: Increase solution stirring, dilute the solution to 1.72 if the relative density is too high. Heat for one hour at 90-100°C.

6.Why are there areas without luster or with a Yin-Yang effect after polishing?

Analysis: Improper positioning of the workpiece relative to the cathode or mutual shielding between workpieces.
Solution: Adjust the workpiece appropriately to ensure proper alignment with the cathode and rational distribution of electrical power.

7.Why are some points or areas not bright enough, or vertical dull streaks appear after polishing?

Analysis: Bubbles generated on the workpiece surface during the later stages of polishing have not detached in time or are adhering to the surface.
Solution: Increase current density to facilitate bubble detachment, or increase solution stirring speed to enhance solution flow.

8.Why are contact points between parts and fixtures lackluster with brown spots while the rest of the surface is bright?

Analysis: Poor contact between parts and fixtures causing uneven current distribution, or insufficient contact points.
Solution: Polish the contact points on the fixtures for good conductivity, or increase the contact area between parts and fixtures.

9.Why are some parts polished in the same tank bright, while others are not, or have localized dullness?

Analysis: Too many workpieces in the same tank causing uneven current distribution or overlapping and shielding between workpieces.
Solution: Reduce the number of workpieces in the same tank or pay attention to the arrangement of workpieces.

10.Why are there silver-white spots near the concave parts and contact points between parts and fixtures after polishing?

Analysis: Concave parts are shielded by the parts themselves or the fixtures.
Solution: Adjust the position of the parts to ensure the concave parts receive electrical lines, reduce the distance between electrodes, or increase current density appropriately.



Post time: Jan-03-2024