What problems will appear in the process of mold mirror polishing?
Mirror polishing means that the surface roughness of the workpiece can reach 12 levels or more after multiple polishing. The process is to use sandpaper with different roughness to polish the surface of the workpiece with flexible polishing tools and abrasive particles or other polishing media.
Mold polishing will undergo scale changes during the heat treatment process, and correction procedures are required. Moreover, the surface finish of the mold will be affected by the heat treatment medium. Because scale/shape changes and/or surface deformation will occur during the heat treatment process, the mold needs to be finely ground, so there is no need to grind the mold surface to a very smooth surface before heat treatment.
The question encountered in mold polishing is "over-polishing". Over-polishing means that the longer the polishing time, the worse the appearance of the mold. There are two scenes when there is over-polishing, namely "orange peel" (orange peel) and "micropits" (pinholes). Over-polishing occurs mostly in mechanical polishing. "Orange peel" (orange peel) The irregular and rough appearance is called "orange peel" (orange peel). There are many different factors for the occurrence of "orange peel" (orange peel). The common factor is that the mold surface is overheated. Or excessive carburization, and the polishing pressure is too high and the polishing time is too long. The harder steel can accept the greater polishing pressure, and the softer steel is prone to over-polishing. The study confirmed that the time of over-polishing is due to the hardness of the material. It's different. Finding that the appearance quality is not good, many people will add polishing pressure and extend the time. This practice usually makes the appearance quality worse.