jinsi ya kuchagua mold sahihi na kesi ya kupoteza kufa

Mold selection
Die Material Selection is a very important link in the whole die making process. Uteuzi wa Nyenzo ya Die unahitaji kukidhi kanuni tatu, kufa ili kukidhi upinzani wa kuvaa, nguvu na ushupavu na mahitaji mengine ya kazi, kufa ili kukidhi mahitaji ya mchakato, na kufa lazima kukidhi matumizi ya kiuchumi. Hali ya kukunja inahitaji
1. Upinzani wa kuvaa. When the blank is plastically denatured in the die cavity, it flows and slides along the surface of the die cavity, causing severe friction between the die cavity surface and the blank, which leads to the failure of the die due to wear. Kwa hiyo, the wear resistance of the material is one of the most basic and important properties of the die. Ugumu ni sababu kuu inayoathiri upinzani wa kuvaa. Kwa ujumla, the higher the hardness of the die parts, the smaller the wear amount, the better the wear resistance. Zaidi ya hayo, upinzani wa kuvaa pia unahusiana na aina, amount, umbo, ukubwa na usambazaji wa carbudi katika nyenzo.
2. Strong toughness, die working conditions are mostly very bad, some often bear a larger impact load, resulting in brittle fracture. In order to prevent die parts in the work of sudden brittle fracture, 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. Utendaji wa fracture ya uchovu, die work in the long-term effect of cyclic stress, often lead to fatigue fracture. Its forms include low-energy repeated impact fatigue fracture, fracture ya uchovu wa mvutano, contact fatigue fracture and bending fatigue fracture. The fatigue and fracture properties of the die mainly depend on its strength, ukakamavu, ugumu, na maudhui ya inclusions katika nyenzo.
4. Utendaji wa joto la juu, when the working temperature of the mold is higher, will reduce the hardness and strength, leading to mold early wear or plastic deformation and failure. Kwa hiyo, the mold material should have high anti-tempering stability, in order to ensure that the mold in the working temperature, with a higher hardness and strength.
5. Resistance to cold and hot fatigue. Some dies are heated and cooled repeatedly in the working process, which makes the surface of

The die cavity subject to tension and pressure strain stress, causes surface cracking and spalling, increases friction, and hinders plastic deformation, reduced Dimensional accuracy, resulting in mold failure. Cold and hot fatigue is one of the main failure forms of hot working dies, and this kind of dies should have high cold and hot fatigue resistance. 6. Upinzani wa kutu, some molds such as plastic mold in the work, because of the presence of chlorine, fluorine and other elements in plastic, heat after decomposition out HCI, HF and other strong corrosive gas, erosion mold cavity surface, increase its Surface roughness, increase wear failure.
1) The material of the main working parts of the mold is improperly selected. The material has poor performance and is not wear-resistant; the die steel has not been refined and has a large number of smelting defects; the convex and concave molds, forging blanks and the forging process are not perfect, and there are hidden dangers of heat treatment.

2) Die structure design problem, the die structure is unreasonable. The slender punch is not designed with a reinforcement device, the discharge port is not smooth and piles up, and the discharge force is too large, and the punch is subjected to increased alternating load.

3) The ukungu making process is imperfect, which is mainly manifested in the poor internal quality of the convex and concave die forging blanks, and the heat treatment technology and process have problems, resulting in the convex and concave molds being incompletely quenched, soft spots and uneven hardness. Sometimes microcracks or even cracks occur, grinding and polishing are not in place, and the surface roughness value is too large.

4) No lubrication or lubrication but poor effect