Causes of die casting mold failure-Shuangcheng Hardware |Die Cast Product|Die Casting Mould

Causes of die casting mold failure

Date：

2022-04-06

Due to the long production cycle, large investment, high manufacturing accuracy and high price of the die casting mold, we expect a long service life of the mold. However, due to the harm of a series of internal and external factors such as materials and processing, the mold is scrapped due to premature failure, resulting in great consumption.

Due to the long production cycle, large investment, high manufacturing accuracy and high price of die casting die, it is expected that the die will have a long service life. However, due to the hazards of a series of internal and external factors such as materials and processing, the die will be scrapped due to premature failure, resulting in huge consumption

The main failure forms of the die casting die include bevel, corner crack, crack, hot crack (crack), scratch, wear, etc. The main reasons for the failure of the die casting die are: defects of the material itself, difficulties in processing, use, maintenance and heat treatment

As we all know, the application standard of die casting die is extremely extreme. Take aluminum die casting die as an example, the melting point of aluminum is 580-740. During application, the temperature of aluminum liquid is controlled at 650-720. In die casting without heating the die, the temperature of the cavity surface rises from room temperature to liquid temperature, and the cavity surface bears a large tensile stress. When ejecting, the cavity surface bears a large compressive stress. After more than 1000 times of die casting, Cracks and other defects will occur on the surface of the mold

It is not difficult to see that the application standard of die casting is fast heating and fast cooling. The die material should be a hot working die steel with high cold and hot fatigue resistance, fracture toughness and thermal stability. H13 (5Cr5CoV1Si) is a widely used material at this stage. It is known that 80% of overseas cavities are made of H13 material, and 3Cr2W8V is still widely used in China, but 3Cr2W8VT_ Poor process characteristics, poor heat transfer, high coefficient of linear expansion, and high thermal stress during operation, resulting in die cracking or even cracking. Moreover, when heated, it is easy to carburize, which reduces the wear resistance of the die. Martensitic steel is suitable for the die with low requirements on wear resistance and corrosion resistance, which is resistant to hot cracking. Tungsten molybdenum and other heat-resistant alloys are limited to small and medium-sized inserts with severe hot cracks and corrosion. Although these alloys are fragile and have vacancy sensitivity, they have the advantages of excellent heat transfer and excellent adaptability to the die casting die of thick die castings that must be cooled but cannot be equipped with water channels. Therefore, H13 still has satisfactory performance under effective heat treatment and production management

The materials used to manufacture the die casting die shall meet the design requirements in all aspects to ensure the design service life of the die casting die under its normal use standard. Therefore, before the capital is put into production, a series of inspections shall be carried out to solve the material problems. To prevent the initial scrap of the mold and the consumption of processing costs caused by poor materials, the common inspection methods include macro corrosion inspection, metallographic inspection and ultrasonic inspection

(1) Macro corrosion inspection: inspect the porous structure, shrinkage porosity, cracks, cracks, non-metallic material impurities, hammering cracks and joints on the surface of main materials

(2) Metallographic examination, to check the shrinkage, distribution, grain size and intergranular impurities of cementite on the dislocation of the main material

(3) Ultrasonic inspection, mainly to inspect the internal defects and dimensions of materials