1. Wear resistance
When the billet is plastic denaturated in the mold cavity, it flows and slides along the surface of the mold cavity, resulting in intense friction between the surface of the mold cavity and the blank, which leads to the failure of the mold due to wear. So the wear resistance of the material is one of the basic and important properties of the die. Hardness is the main factor affecting wear resistance. - Under normal circumstances, the higher the hardness of the die parts, the smaller the wear amount and the better the wear resistance. In addition, the wear resistance is also related to the type, quantity, shape, size and distribution of carbides in the material.
2, strong toughness
The working conditions of molds are mostly very bad, and some often bear large impact loads, which lead to brittle fracture. In order to prevent the die parts from breaking suddenly when working, the die should have high strength and toughness. The toughness of the die mainly depends on the carbon content, grain size and microstructure of the material.
3. Fatigue fracture performance
In the process of die working, fatigue fracture is often caused by the long-term action of cyclic stress. The fracture forms include multi-impact fatigue fracture with small energy, tensile fatigue fracture, contact fatigue fracture and bending fatigue fracture. The fatigue fracture properties of the die mainly depend on its strength, toughness, hardness, and the content of inclusions in the material.
4, high temperature performance
Talk about when the working temperature of the mold is higher, it will make the hardness and strength decrease, leading to the early wear of the mold or plastic deformation and failure. The die material should have high tempering stability to ensure that the die has high hardness and strength at the working temperature.
5, cold and hot fatigue resistance
Some molds are in the state of repeated heating and cooling in the process of work, so that the cavity surface tension, pressure change stress, cause surface cracking and peeling, increase friction, hinder plastic deformation, reduce dimensional accuracy, thus leading to mold failure. Hot and cold fatigue is one of the main forms of hot working die failure, so this kind of die should have high resistance to cold and hot fatigue.
6, corrosion resistance
When some molds, such as plastic molds, work, due to the presence of chlorine, fluorine and other elements in the plastic, after being heated, they decompose and precipitate HEI, HF and other strong erosive gases, which erode the surface of the mold cavity, increase its surface roughness and aggravate wear failure.