If you want to increase the service life of the mold and save costs, the hook net tells you that you can try to refine the grains by heat treatment. The use of grain refinement to improve the mechanical properties of the material can simultaneously increase the strength at room temperature and also increase the fatigue limit. In addition, the obtaining of fine crystal grains is relatively simple and can be obtained through appropriate heat treatment. Cyclic ultra-refining heat treatment is a common method for heat-refining grains. It only performs two steps of heating and cooling in cyclic heat treatment. It is a relatively simple and easy method for grain refining.
In the past, cyclic superfine heat treatment was only used for casting Ti-46Al-8.5Nb-0.2W alloy to transform its coarse lamellar structure into uniform and fine porridge structure. Now, this heat treatment can also be used for carbon tool steel materials, and it has also achieved ultra-fine grain. Its heat treatment process uses two salt bath furnaces. The workpiece is now placed in a high temperature salt bath furnace to be heated to the normal quenching temperature, and then quickly transferred to another salt bath furnace for cooling. This cycle is repeated, and finally a high temperature is performed. Quenched and then tempered for two hours.
Machining tests show that the carbide and residual austenite are uniformly distributed as spherical particles, and the martensite is relatively fine. By punching the convex and concave dies of the steel motor rotor core through four cycles of heat treatment, its life can be increased by more than 30%, and it has a very obvious effect on reducing the occurrence of cracks.
The above method can be used to obtain a uniform and fine structure. The principle is that it takes full advantage of the effects of rapid heating and cyclic processing to quickly heat, generate a large number of austenite nuclei, and appear and obtain fine grains; this The faster the process proceeds, the greater the temperature difference, and the better the refinement effect it gets.
