The quenching deformation and cracking of plastic mold operating parts and the early fracture of the application process are all related to the hot working process of the mold.
(1) Casting process, which is an important link in the manufacturing process of mold operating parts. Regarding molds for high alloy tool steels, skills are usually required for metallographic arrangements such as carbide distribution. In addition, the scale of casting temperature should be strictly controlled, the correct heating standard should be formulated, the correct casting force method should be adopted, and slow cooling or timely annealing after forging should be used.
(2) Preliminary heat treatment. Depending on the information and requirements of the mold operating parts, pre-heat treatment processes such as annealing, normalizing or quenching and tempering should be adopted to improve the arrangement, eliminate the disadvantages of the casting blank arrangement, and improve the processing technology. High-carbon alloy mold steel can eliminate reticulate cementite or chain carbide through proper preliminary heat treatment, spheroidize and refine carbide, and promote uniformity of carbide distribution. This will help to ensure the quality of quenching and tempering and improve the life of the mold.
(3) Quenching and tempering. This is a key link in the heat treatment of plastic molds. If overheating occurs during quenching and heating, the workpiece will not only cause greater brittleness, but also simply cause deformation and cracking during cooling, which seriously affects the life of the mold. Special attention should be paid to the prevention of oxidation and decarburization when the die is quenched and heated. The heat treatment process standards should be strictly controlled. If the conditions are agreed, vacuum heat treatment can be used. After quenching, it should be tempered in time, and different tempering processes should be adopted according to the technical requirements.
