How to solve the common problems in polishing


Excessive polishing
The biggest problem most frequently encountered in the polishing process is "over polishing" which means that the longer the polishing time, the poorer the quality of the mold surface.
If there is excessive polishing, there are two phenomena: "orange peel" and "pitting"
  
The cause of "pitting" on the surface of the workpiece
Because there will be some non-metallic impurities in the steel, pitting from the surface of the steel during the polishing process results in pitting corrosion. The reasons for pitting corrosion are as follows:
1. The surface of the mold is rusted.
2. The black leather is not removed.
3. The polishing pressure is too high and the polishing time is too long.
4. The purity of the steel is not enough and the content of hard impurities is high.

Measures to eliminate pitting artifacts
1. Try to use the shortest polishing time and minimal polishing power.
2. The softest polishing tool should be avoided when the sand size is less than 1 mm.
3. Re-grind the surface carefully. The grain size is a bit coarser than the grain size used previously. The final step of grinding is done with a soft and crushed stone.

Elimination of the "orange peel" of the workpiece
When it is found that the surface quality is not ideally thrown, many people's practices will increase the polishing pressure and extend the polishing time, which will make the surface quality become more unsatisfactory.

The following methods can be used to remedy:
1) Perform stress relief at a temperature lower than the tempering temperature of 25 °C, use the finest sand number before polishing to achieve a satisfactory result, and finally polish with lighter force.
2) Remove the defective surface and grind it to a coarser level than the previously used sand number, then grind it to a lesser degree than before.

👆The cause of the "orange peel" on the workpiece

The rough surface is called "orange peel", and there are many reasons to produce "orange peel". The most common cause is due to overheating of the mold surface or excessive carburization. Excessive polishing pressure and long polishing time result in "orange peel". main reason.

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