Views: 2 Author: Site Editor Publish Time: 2020-09-28 Origin: Site
The hot working quality of the die has great influence on the performance and service life of the die. In the actual life and work of our mold workshop on the design and production of various molds are required to keep improving, but the specific operation will also have problems, which we follow mold manufacturers to discuss the use of stamping die problems.
The quenching deformation and cracking of the working parts of the mould and the early fracture of the using process are all related to the hot working technology of the mould.
(1) Forging process, which is an important link in the manufacturing process of mold working parts.
For the die of high alloy tool steel, the technical requirements for the microstructure such as carbide distribution are usually put forward. In addition, the forging temperature range should be strictly controlled, correct heating specifications should be formulated, correct forging force method should be adopted, and slow cooling or timely annealing should be adopted after forging.
(2) Preparatory heat treatment.
According to the different materials and requirements of the working parts of the mold, annealing, normalizing or tempering and other preparatory heat treatment processes should be used to improve the organization, eliminate the organizational defects of forging blank, and improve the processing technology. After proper preparatory heat treatment, the reticulated secondary cementite or chain carbides can be eliminated, the carbides can be spheroidized and refined, and the distribution uniformity of carbides can be promoted. This is conducive to ensure the quenching and tempering quality, improve the life of the mold.
(3) Quenching and tempering.
This is the key link in mold heat treatment. If overheating occurs during quenching heating, it will not only cause greater brittleness of the workpiece, but also easily cause deformation and cracking during cooling, seriously affecting the life of the die. Special attention should be paid to prevent oxidation and decarburization during quenching and heating of punching die. Heat treatment process specifications should be strictly controlled. Vacuum heat treatment can be used if conditions permit. After quenching should be tempered in time, and according to the technical requirements to adopt different tempering process.
(4) Stress relief annealing.
The purpose of the annealing treatment is to eliminate the internal stress caused by rough machining, so as to avoid excessive deformation and crack caused by quenching. For the mould with high precision, after grinding or electric machining, the mould also needs to be de-stressed and tempered, which is helpful to stabilize the precision of the mould and improve its service life.