1. Wear resistance: When the blank is plastically deformed in the mold cavity, it moves and slides along the surface of the cavity, causing violent friction between the surface of the cavity and the blank, which causes the mold to take effect due to wear. Therefore, the wear resistance of materials is one of the most fundamental and important functions of the mold. Hardness is a secondary factor affecting wear resistance. Under normal conditions, the higher the hardness of the mold parts, the smaller the amount of wear and the better the wear resistance. In addition, wear resistance is also related to the type, quantity, shape, size and dispersion of carbides in the data.
2. The working conditions of the strong and tough die tools are mostly very bad, and some often accept larger impact loads, resulting in brittle fracture. In order to avoid the sudden brittle fracture of mold parts during work, the mold must have high strength and toughness. The toughness of the mold mainly depends on the carbon content, grain size and structure of the material.
3. Fatigue fracture function In the process of mold work, under the temporary action of cyclic stress, fatigue fracture is often caused. The methods include low-energy repeated impact fatigue fracture, tensile fatigue fracture, contact fatigue fracture, and bending fatigue fracture. The fatigue fracture function of the mold mainly depends on its strength, toughness, hardness, and the content of inclusions in the data.
4. Low temperature function When the working temperature of the mold is higher, it will decrease the hardness and strength, and cause the mold to wear out or plastic deformation in the late stage to take effect. Therefore, the mold material should have higher resistance to tempering fluctuations to ensure that the mold has a higher hardness and strength at the working temperature.
5. Anti-cold and heat fatigue function. Some die tools are in the form of repeated heating and cooling during the work process, which causes the surface of the cavity to be subjected to tension and pressure to change stress, causing surface cracks and peeling, increasing friction, and obstructing plastic deformation. The dimensional accuracy is reduced, which causes the mold to take effect. Heat and cold fatigue is one of the secondary ways that hot work die tools take effect. This type of mold should have a high resistance to cold and heat fatigue.
6. Corrosion resistance When some die tools such as plastic die tools are working, due to the presence of chlorine and fluorine in the plastics, strong corrosive gases such as HCI and HF will be resolved after heating, which will corrode the surface of the mold cavity and increase its surface roughness. , The aggravated wear takes effect.
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