1. Wear resistance
When the blank is plastically denatured in the mold cavity, it moves and slides along the surface of the cavity, resulting in violent conflict between the surface of the cavity and the blank, and then causes the die failure due to wear. Therefore, the material wear resistance is one of the most basic and important functions of the mold.
Hardness is the primary factor affecting wear resistance. Generally speaking, the higher the hardness of die parts is, the smaller the wear loss is, and the better the wear resistance is. In addition, the wear resistance is related to the type, quantity, shape, size and distribution of carbides.
2. Strong tolerance
Most of the working conditions of dies are very bad, some of them often bear large impact load, and then lead to brittle cracking. In order to avoid sudden brittle fracture of die parts in operation, the mold should have high strength and endurance.
The resistance of die depends primarily on the carbon content, grain size and microstructure of the material.
3. Fatigue cracking function
In the process of mold operation, fatigue cracking is often caused by the long-term effect of cyclic stress. The methods include repeated impact fatigue cracking with small energy, stretching fatigue cracking, touch fatigue cracking and tortuous fatigue cracking.
The fatigue cracking function of the die mainly depends on its strength, resistance, hardness and the content of inclusions in the prediction.
4. High temperature function
When the working temperature of the die is higher, the hardness and strength will be decreased, which will lead to the early wear of the die or plastic deformation and failure. Because the mould data should have high tempering stability to ensure that the mold has high hardness and strength at the operating temperature.
5. Cold and hot fatigue resistance
Some molds are in the state of repeated heating and cooling in the process of operation, which causes the surface of the cavity to crack and fall off, increase the conflict force, prevent the plastic deformation, reduce the scale accuracy, and then lead to die failure. Cold and hot fatigue is one of the most important ways of hot working die failure. This kind of mold should have high resistance to cold and hot fatigue.
6. Corrosion resistance
Some moulds, such as plastic moulds, are decomposed into HCI, HF and other strong corrosive gases due to the presence of chlorine, fluorine and other elements in the plastic mold during operation, which corrodes the surface of the mold cavity, increases the surface roughness and aggravates the wear failure
