In the early stage of the extrusion die, a reasonable surface nitriding process must be carried out on the die. It should be noted that surface nitriding cannot be completed at one time. During the service period of the mold, repeated nitriding treatment must be carried out 3-4 times. Generally, the thickness of the nitriding layer is required to reach about 0.15mm. The mold cavity should be cleaned, and no alkali residue or foreign particles should be left. Under normal circumstances, the number of nitriding times of the mold should not exceed 4-5 times. It should be noted that nitriding can only be carried out after a suitable production process in the early stage of nitriding.

Before the mold is put on the machine, the working belt must be ground and polished, and the working belt is generally required to be polished to a mirror surface. Before the mold is put on the machine, the working belt must be ground and polished, and the working belt is generally required to be polished to the mirror to check the flatness and verticality of the working belt of the mold before assembly. The quality of nitriding determines the polishing finish of the working belt to a certain extent. The mold cavity must be cleaned with high-pressure air and brushes, and there must be no dust or foreign matter, otherwise the working belt will be easily pulled down by the metal flow, and the extruded profile products will have defects such as rough surface or scribing.

During extrusion production, the heat preservation time of the mold is generally about 2-3 hours. When using the mold, there must be a mold support, a mold sleeve and a support pad that match the mold, so as to avoid the mold outlet surface and the support pad due to the excessively large inner hole of the support pad. The contact surface is too small, causing the mold to deform or crack.

Use the correct alkaline cleaning (cooking) method. After the mold is unloaded, the mold temperature is at 500°C. If the mold temperature drops rapidly, the mold is prone to cracking. The correct method is to place the mold in the air at 100°-150°C and then immerse it in alkaline water after the mold is unloaded. After the extrusion is completed, the extrusion rod retreats first before the extrusion cylinder, and the pressure remains in the extrusion cylinder, and then the extrusion cylinder retreats. At the same time, part of the residual aluminum in the shunt hole of the mold can be pulled out with the pressure residual, and then the alkali is carried out. cook.

The use of the mold is used from low to high and then to low. In the middle of the use of the mold, since the performance of the mold has basically been in a stable state, the use intensity can be appropriately increased. In the later stage, the metal structure of the mold has begun to deteriorate, and the fatigue strength, stability and toughness have begun to enter a decline curve after long-term production and service. At this time, the strength of the mold should be appropriately reduced until the mold is scrapped.

Strengthen the use and maintenance records of molds in the extrusion production process, improve the tracking records of each set of molds, and strengthen the use and maintenance records of molds in the extrusion production process to facilitate management.