The detailed heat treatment process of stamping mould is introduced
source：未知 Writer： hmdmould Time：2021-05-22 10:58 Browse：
Because of the different stamping process and the different operating conditions, there are many reasons that lead to the mould burst. The following comprehensive analysis of the stamping mould in the planning, production and use of the process, the cause of the mould burst, and put forward the corresponding improvement measures.
Heat treatment: deformation caused by improper tempering and tempering process
It has been proved that the hot working quality of the mould has great influence on the performance and service life of the mould. Through the analysis and statistics of the causes of mould failure, it can be seen that the "accidents" of mould failure caused by improper heat treatment account for more than 40%.
(1) Casting process
This is an important link in the production process of mold parts. For high alloy tool steel moulds, the technical requirements for material carbide dispersion and other metallographic structures are generally put forward.
(2) Heat treatment preparation
According to the different materials and requirements of the mould operating parts, annealing, normalizing or tempering should be selected to improve the layout, eliminate the defects of the slab arrangement and improve the processing technology.
High carbon alloy mould steel through appropriate heat treatment, eliminate the network secondary carbides or chain carbides, the carbide spheroidization refinement, promote the uniform distribution of carbides, is conducive to ensure the quality of quenching and tempering, improve the life of the mould.
(3) quenching and tempering
This is the key link of mold heat treatment. If overheating occurs in the quenching and heating process, it will not only make the workpiece form a greater brittleness, but also will simply cause deformation and cracking in the cooling process, which will seriously affect the service life of the mold.
When the mould is quenched and heated, special attention should be paid to preventing oxidation and decarburization, and the heat treatment process should be strictly controlled. When conditions permit, vacuum heat treatment can be chosen. After quenching should be timely tempering, and according to the technical requirements to choose different tempering process.
(4) Stress relieving annealing
After rough machining, the working parts of the mould shall undergo stress relief annealing. Its purpose is to eliminate the internal stress produced by rough machining and avoid excessive deformation and crack during quenching.
For the mould with high precision requirements, it is necessary to eliminate stress and temper after grinding or electrical processing, which is conducive to stabilize the precision of the mould and improve the service life.
Bad flatness and deformation in mold grinding
The surface quality of the working parts of the mold has a very close relationship with the wear resistance, crack resistance and adhesion resistance of the mold, which directly affects the service life of the mold, especially the surface roughness value has a great influence on the life of the mold. The large one.
If the surface roughness value is too large, there will be stress concentration in the use process, simply crack between the peak and valley, affect the durability of the mold, affect the corrosion resistance of the workpiece surface, directly affect the service life and precision of the mold, therefore, you should pay attention to the following points:
(1) In the process of mold workpiece processing, grinding and burning the appearance of parts should be avoided, and the grinding process conditions and methods should be strictly controlled (such as grinding wheel hardness, particle size, coolant, feed and other parameters);
(2) In the process of processing, the surface of the working parts of the mould should be avoided such macroscopic defects as knife marks, interlayers, cracks, impact scars and so on. The existence of these defects will cause stress concentration, which will become the root of cracking and lead to the early failure of mould.
(3) The method of grinding, grinding and polishing is adopted to obtain a smaller surface roughness value and improve the service life of the mold.