Common problems and solutions in electrolytic polishing

Why are there spots or small pieces on the surface that appear to have not been polished after electrolytic polishing?
Before polishing, the oil removal is not thorough, and there are still oil stains on the surface.
Select a stainless steel degreaser, dissolve it in (15-20) and use it. Soak it for 10-20 minutes at 10~40 ℃. If the degreaser has been used for a long time, consider replacing it with a new tank solution.
Why are there gray black patches on the surface after polishing?
The oxide skin has not been completely removed, and there is still oxide skin present locally.
Increase the force to remove the oxide skin on the surface of the workpiece. You can consider choosing a specialized pickling solution to remove oxide scale.
3. What is the cause of excessive corrosion at the corners and tips of the workpiece after polishing?
Excessive current at corners and tips, or high electrolyte temperature and polishing time can lead to excessive dissolution.
Adjust the current density or solution temperature, or shorten the time. Check the electrical position and set shielding at the edges and corners.
4. Why is the workpiece not bright and appears gray and dark after polishing?
If the process indicators are all correct, it may be that the electrochemical polishing solution has aged and is ineffective, or the effect is not obvious.
Check if the electrolytic polishing solution has been used for too long, if the quality has decreased, or if the proportion of solution components is out of balance, and then make corresponding adjustments.
What is the reason for white stripes on the surface of the workpiece after polishing?
The relative density of the solution is too high, the liquid is too thick, and the relative density is greater than 1.8.
Increase the stirring degree of the polishing solution. If the relative density of the electrolyte is too high, add some fresh polishing solution or dilute it with an appropriate amount of water to a specific gravity of about 1.77.
6. Why are there negative and positive surfaces on the polished surface, as well as local lack of luster?
The position where the workpiece is placed is not aligned with the cathode, or the workpiece is shielded from each other.
Adjust the workpiece appropriately to ensure the appropriate position between the workpiece and the cathode, and ensure a reasonable distribution of power.
7. After polishing, the surface of the workpiece is flat and smooth, but some points or blocks are not bright enough, or there are vertical dark stripes. What is the general reason for this?
It may be that the bubbles generated on the surface of the workpiece during the later polishing stage did not detach and adhere to the surface in a timely manner, or there were airflow lines on the surface.
Increase the current density to increase the amount of gas evolution for bubble desorption, or increase the stirring speed of the solution to increase the flow of the solution.
8. What is the reason for the lack of luster and brown spots at the contact points between the workpiece and the hanging fixture, and the rest of the surface being shiny?
It may be due to poor contact between the component and the fixture, resulting in uneven current distribution, or a lack of contact points between the component and the fixture.
Polish the contact points of the hanging device to ensure good conductivity, or increase the contact area between the component and the hanging device.
9. None of the polished parts in the same groove may be bright, some may not be bright, or some may not be bright locally.
There are too many polished workpieces in the same slot, resulting in uneven current distribution or overlapping and shielding between workpieces.
Reduce the number of polished workpieces in the same slot, or pay attention to the placement of workpieces.
10. Why are there silver white spots near the concave part of the polished workpiece and the contact point between the workpiece and the hanger?
It may be that the concave part of the workpiece is shielded by the workpiece itself or the hanging tool.
Properly change the position of the workpiece so that the concave part can receive power lines, reduce the distance between electricity, or increase current density.
11. We have strictly followed the process specifications for operation. Why is there more or less excessive corrosion on the surface of no parts after polishing?
Whether the solution temperature is too high or the current density is too high may be a problem with pre-treatment before polishing.
Strictly implement the pre-treatment operation of electrochemical polishing to avoid excessive corrosion during the pickling process. Do not leave cleaning water on the surface of the workpiece and bring it into the polishing groove.
12. Why is there so much foam after using electrolyte for a long time?
The surface of the workpiece has not been degreased, and some oil stains float on the surface of the electrolyte, which brings difficulties to the operation.
Remove the oil stains from the surface and remove them before polishing.
13. After polishing, wipe it clean and throw it away without luster. What is the reason for the light blue shadow?
It may be that the electrochemical polishing solution has not been heated or energized after preparation, or the operating temperature of the solution is too low.
Heat the electrolytic polishing solution at 60 ℃ for one hour or heat the electrolyte to the specified temperature.
Why do brown spots appear when the workpiece is removed from the groove after polishing?
It may be due to insufficient electric polishing or a short time.
Choose to extend the polishing time appropriately. If it is ineffective, it may be due to insufficient temperature or current density.
Why is it easy to experience sparking during electrolysis?
There are three factors that can cause this phenomenon. Firstly, the contact point between the fixture and the workpiece is not firm. Secondly, the electrolyte density is too low. Thirdly, the current density is too high.
Change multiple methods of connecting the fixture to the workpiece, and try to increase the contact points between the fixture and the workpiece as much as possible. If the electrolyte density is too low, the electrolyte can be replaced.
What is the effect of operating temperature of stainless steel electrolyte on electrolytic polishing?
The usage temperature of the electrolyte is between 50-90 ℃, with lower temperature and slower polishing speed, resulting in a decrease in brightness. If the temperature is too high, the liquid will accelerate the corrosion of the workpiece, which can easily cause excessive corrosion of the workpiece, and the effective components of the electrolyte are easy to decompose.
When the temperature is low, it should be heated to the specified temperature. Various heating tubes (such as quartz or titanium material heating tubes) can be used for heating. The temperature will rise after prolonged operation. When the temperature exceeds 90 ℃, the work should be stopped. Mixing or cooling circulation can be used for heat dissipation. The optimal operating temperature is 50-70 ℃
17. The surface of stainless steel workpieces is uneven and the pits are convex. What is the reason for this?
There is a lot of surface rust, and the electrolyte only undergoes micro corrosion leveling. The more corroded electrolyte cannot be completely removed. If the polishing time is extended, a large amount of iron ions will sink into the bottom of the electrolyte, reducing its service life.
Thoroughly clean the rust on the surface of the workpiece. Choose a powerful specialized pickling activation solution to perform pickling activation treatment first.
18. Why do new electrolyte polishing also show pitting?
Perhaps the water content in the newly configured electrolyte is too high.
Warm the electrolyte to 60-80 ℃ for 1-3 hours and allow the water to evaporate appropriately.