Precautions for the heating process of injection molds

In order to make the injection mold process produce exquisite workpieces, we will heat the injection mold, which can not only improve the precision of the injection mold, but also improve the quality and precision of the workpiece. Regarding the matters needing attention in the heating process of injection molds, there are four main links, which are the casting process, preparation for heat treatment, quenching and tempering, and stress relief annealing. Here are the points of attention for each link.

Casting process. This is an important link in the manufacturing process of working parts for injection molds. For Automotive Injection Molding of high-alloy tool steels, technical requirements are usually put forward for the metallographic structure such as the dispersion of material carbides. In addition, the casting temperature scale should be strictly controlled, the correct heating standard should be drafted, the correct casting force method should be selected, and the slow cooling or timely annealing after forging should be performed.

Prepare for heat treatment. Depending on the materials and requirements of the working parts of the injection mold, annealing, normalizing or quenching and tempering should be used to prepare heat treatment processes to improve the organization, remove the structural shortcomings of the casting blank, and improve the processing technology. The high-carbon alloy die steel can remove the network secondary cementite or chain carbide through appropriate preparation heat treatment, so that the carbide can be spheroidized and refined, and the uniformity of carbide dispersion can be accelerated. This will help ensure the quality of quenching and tempering and improve the life of the mold.

Quenching and tempering. This is the key link in mold heat treatment. If overheating occurs during quenching and heating, it will not only cause the workpiece to form greater brittleness, but also easily cause deformation and cracking when it becomes cold, which will seriously affect the life of the mold. Special attention should be paid to prevent oxidation and decarburization when the die is quenched and heated, and the heat treatment process standard should be strictly controlled. When conditions permit, vacuum heat treatment can be selected. After quenching, it should be tempered in time, and different tempering processes should be selected according to the skill requirements.

Stress relief annealing. After processing the parts of the injection mold, the stress relief annealing treatment should be carried out. The purpose is to relieve the internal stress formed by rough machining, so as to avoid excessive deformation and cracks caused by quenching. For molds with high precision requirements, stress relief and tempering treatment are required after grinding or electrical machining, which is conducive to stabilizing the precision of the mold and improving the service life. Heat treatment is a process that every injection mold needs to experience before leaving the factory, but not every injection mold factory can implement it in a standard manner. It also needs to pay attention to process skills. The mold factory has set a new standard for mold heating for the industry, making Each set of molds produced has reached a fine height.