aluminum alloy die casting die steel?

1. High tempering resistance and hot and cold fatigue resistance

Aluminum alloy die-casting molds for continuous mass production should maintain their high hardness for a long time under a certain temperature, and must not stick to the mold to produce oxide scale. Therefore, the mold should have good oxidation resistance and tempering stability.

aluminum alloy die-casting mold is repeatedly heated and cooled by high temperature, and continues to expand and contract, resulting in alternating thermal stress. When this stress exceeds the elastic limit of the mold material, repeated plastic deformation occurs, causing thermal fatigue.

At the same time, the surface of the mold is corroded and oxidized by the molten metal for a long time, and microcracks will gradually occur. In most cases, thermal fatigue is an important factor in determining the life of die-casting molds.

2. Sufficient strength, hardness, plasticity and heat resistance

aluminum alloy die-casting mold is injected with molten metal, it is easy to deform or even crack due to high temperature, high pressure and thermal stress. Therefore, the die steel should have sufficient high temperature strength and toughness, as well as high hardness and heat resistance at working temperature.

3. Good thermal conductivity

aluminum alloy die-casting mold at a high temperature of 600-700 ℃ for a long time. In order to ensure other properties, it must have good thermal conductivity.

4. Good resistance to molten metal damage

, the die-casting pressure is also increasing, from 20-30MPa at low pressure to 150-500MPa at high pressure. High temperature and high pressure casting will produce obvious melting damage, and the mold should have greater resistance to this.

For this reason, the mold material must have high high temperature strength, low affinity for molten metal, small mold indicating roughness, appropriate protective layers such as oxidized molds and nitrided layers attached, and no decarburized layer.

5. Good air permeability, small heat treatment deformation

In general, the manufacturing method of the die casting mold is to carve the mold material after annealing out of the cavity, and then heat treat to obtain the required hardness; or heat treat the mold material before carving the cavity to obtain the required hardness.

heat treatment has high hardness and strength, and is not easy to produce melting loss and thermal fatigue.

No matter which method is used for heat treatment, it is necessary to obtain uniform hardness. Therefore, good hardenability is required, especially when the cavity is first engraved and then heat treated. Materials with small deformation should be used for heat treatment, which is especially important for large-size molds.