1, wear resistance
When the blank is deformed in the mold cavity, it flows and slides along the cavity surface, causing severe friction between the cavity surface and the blank, which causes the mold to fail due to wear. So the wear resistance of the material is the most basic and most important performance of the mold.
Hardness is the main factor affecting wear resistance. Under normal circumstances, the higher the hardness of mold parts, the smaller the wear, wear resistance is also better. In addition, the wear resistance is also related to the type, quantity, shape, size and distribution of carbides in the material.
Mold working conditions are mostly very bad, and some often bear a greater impact load, resulting in brittle fracture. In order to prevent the mold parts in the work suddenly brittle fracture, the mold to have a high strength and toughness.
The toughness of the mold depends mainly on the carbon content of the material, grain size and tissue state.
3. Fatigue fracture performance
Mold work in the process, the long-term role in the cyclic stress, often lead to fatigue fracture. Its form has a small energy multiple impact fatigue fracture, tensile fatigue fracture contact fatigue fracture and bending fatigue fracture.
The fatigue fracture properties of the mold are mainly determined by its strength, toughness, hardness, and the content of inclusions in the material.
4. High temperature performance
When the mold working temperature higher, will make the hardness and strength decreased, leading to early wear or plastic deformation of the mold and failure. Therefore, the mold material should have a high resistance to tempering stability, to ensure that the mold at the working temperature, with a high hardness and strength.
5. Resistance to hot and cold fatigue properties
Some molds are in the process of repeated heating and cooling, so that the surface of the cavity by the tension, the role of stress stress, causing the surface cracking and peeling, increased friction, blocking plastic deformation, reducing the size of the accuracy, resulting in Mold failure. Hot and cold fatigue is one of the main forms of hot die failure, to help this type of mold should have a high resistance to hot and cold fatigue performance.
6. Corrosion resistance
Some molds such as plastic mold at work, due to the presence of chlorine in the plastic, fluorine and other elements, heat decomposition after the decomposition of HCI, HF and other strong corrosive gases, erosion mold cavity surface, increase its surface roughness, exacerbate wear failure.