Education of the republic of uzbekistan tashkent state technical university named after islam karimov

Figure 3 Sketch view of heat treatment: 1 punch, 2 inserts, 3 wallpaper, 4 pushers. 
 
Heat resistance (heat resistance) is a characteristic feature of die steels that characterizes 
the steel resistance to surface cracking during heat treatment. The higher the heat resistance, the 
higher the hardness of the steel and the lower the coefficient of thermal expansion. 
Thus, the main additional alloys in the prefabricated stamp are calculated in relation to the 
alloy that has high heat resistance. As a result, the wear of the stamping wallpaper is reduced, it 
can be used after several material changes, and thus the materials of the company are 
economically consumed. 
As an additional hardening, the working surfaces of the tool are subjected to a "fine 
nitriding" effect. Soft nitriding was carried out in cyanide baths containing 40% KCNO and 60% 
NaCN at 570 ° C by blowing with dry air to accelerate oxidation and salt separation. 
quenching 
oil 
rest 
air 

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Fine nitriding improves steel's overpressure resistance, tensile strength and corrosion 
resistance. One of the most important advantages of thin nitriding is the small change in volume 
of this part (increase by 3-10 µm) and the absence of deformation. Therefore, it is recommended 
that cutting and softening be completed first, followed by fine nitriding. 
Practical experience, based on statistics, shows that when using prefabricated dies, the 
number of parts stamped from one die to another is several times greater than the number of 
parts from the same material, the number of parts made by stamping. 
Figure-4. Dependence of the number of produced parts on the die material level. 
 
Conclusion. 
Increasing the durability of dies is one of the important tasks that must be 
considered during their production, repair and operation. The use of ready-made dies from 
chemical and thermal treatment allows to significantly reduce the loss of working time for repair, 
adjustment and manufacture of dies, reduce equipment failure during die replacement, and 
increase the number of stamped parts from one die. At the same time, the production of dies with 
additives, the production of cutting tools increases the overall production cycle, and the use of 
different materials in prefabricated dies and the heat treatment process becomes more expensive.