Factors affecting mold polishing quality
Because the mechanical polishing is mainly completed by manual, so the polishing technology is still the main reason affecting the quality of polishing.In addition, it is also related to mold materials, surface conditions before polishing, and heat treatment process.High quality steel is a prerequisite for good polishing quality. If the surface hardness of steel is uneven or the characteristics are different, it will often produce polishing difficulties.Various inclusions and pores in steel are not conducive to polishing.
1. Influence of Different Hardness on Polishing Process The increase of hardness increases the difficulty of grinding, but the roughness after polishing decreases.As the hardness increases, the polishing time required to achieve lower roughness increases correspondingly.At the same time, the hardness increases, and the possibility of over-polishing decreases accordingly.
2 workpiece surface conditions on the impact of polishing process steel in the cutting machinery processing of the breaking process, the surface will be damaged due to heat, internal stress or other factors, cutting parameters will affect the polishing effect.EDM surfaces are more difficult to grind than ordinary machined or heat-treated surfaces, so precision EDM trimming should be used before the end of EDM, otherwise the surface will form a hardened thin layer.If the EDM finishing specification is not properly selected, the depth of heat-affected layer can be up to 0.4mm.
The hardness of the hardened thin layer is higher than that of the substrate and must be removed.Therefore, it is best to add a rough grinding processing, completely remove the damage to the surface layer, constitute an average rough metal surface, to provide a good basis for polishing processing.