• 2023-08-14
• 458
• 5 Comments

How to solve the problem in the polishing of mold die parts

(1) Excessive polishing

The biggest problem encountered in the daily polishing process of mold parts is "excessive polishing", which means that the longer the polishing time, the worse the quality of the mold surface. There are two phenomena of excessive polishing: "orange peel" and "pitting". Excessive polishing occurs in mechanical polishing.

(2) The reason for the "orange peel" of the workpiece

The irregular rough surface is called "orange peel", there are many reasons for "orange peel", the most common reason is caused by overheating or excessive carburizing of the mold surface, polishing pressure is too large and polishing time is too long is the main reason for "orange peel". For example: polishing wheel polishing, the heat generated by the polishing wheel will easily cause "orange peel". The harder steel can withstand the polishing pressure will be larger, the relatively soft steel is prone to over-polishing, and the research has proved that the time of over-polishing will vary depending on the hardness of the steel.

(3) Measures to eliminate the workpiece "orange peel"

When the surface quality is found to be poor, many people will increase the polishing pressure and extend the polishing time, which often makes the surface quality worse.

The following methods can be used to remedy the problem:

1) Remove the defective surface, grind the particle size slightly coarser than the previous use of sand, and then grind, polishing strength is lower than the previous.

2) Stress relief at a temperature below the tempering temperature of 25 ° C, grinding with the finest sand before polishing until satisfactory results are achieved, and finally polishing with a lighter force.

(4) The cause of the formation of "pitting" on the workpiece surface

Because some non-metallic impurities in the steel, usually hard and brittle oxides, are pulled from the surface of the steel during the polishing process, forming micro-pits or pitting, the main factors that produce "pitting" are the following:

1) The polishing pressure is too large, and the polishing time is too long.

2) The purity of steel is not enough, and the content of hard impurities is high.

3) The surface of the mold is rusty.

4) Black material is not removed.

(5) Measures to eliminate workpiece pitting

1) Carefully re-grind the surface, the sand grain size is slightly coarser than the previously used particle size, using soft and sharpened stone for the final step of grinding before the polishing procedure.

2) The softest polishing tools should be avoided when the size of the sand is less than 1 mm.

3) Use the shortest polishing time and the smallest polishing force as possible.

The polishing of the cavity in the mold manufacturing process is a very important process, which is related to the quality and life of the mold, and also determines the quality of the product. Master the working principle and process of polishing, choose a reasonable polishing method, can improve the quality and life of the mold, and then improve the quality of the product.