Detailed Introduction of Metal Mould Casting Technology (Dongguan Casting Steel Part)
Metal mould casting, also known as hard casting, is a casting method of pouring liquid metal into metal mould to obtain castings. Molds are made of metal and can be used repeatedly (hundreds to thousands of times).
Compared with sand casting, metal to casting has many advantages in technology and economy.
(1) The mechanical function of metal mold castings is higher than that of sand mold castings. The uniform tensile strength and yield strength of the same alloy can be increased by about 25% and 20% respectively. The corrosion resistance and hardness of the alloy are also improved obviously.
(2) The accuracy and surface finish of castings are higher than those of sand castings, and the quality and size of castings are stable.
(3) The process yield of castings is high and the consumption of liquid metals is reduced, which can generally save 15-30%.
(4) Shaping materials can be saved by 80-100% without sand or less sand.
In addition, the production efficiency of metal mould casting is high, the causes of casting defects are reduced, the process is simple, and it is easy to complete mechanization and automation. Although metal mould casting has many advantages, it also has some disadvantages. Such as:
(1) High production cost of metal moulds;
(2) Metal moulds are impermeable and non-retrogressive, which can easily lead to defects such as insufficient washing, cracking of castings or daytime of cast iron castings.
(3) In metal mould casting, the working temperature of the mould, the pouring temperature and the pouring speed of the alloy, the time of the casting staying in the mould, and the paint used have a very sensitive effect on the quality of the casting, which needs to be strictly controlled.
There are some constraints on the weight and shape of the castings that can be produced by metal mould casting, such as the simple shape of ferrous metal; the component of castings can not be too large; the wall thickness is also constrained, and the smaller wall thickness of castings can not be cast. Therefore, when deciding to adopt metal mould casting, the following factors must be taken into account: the shape and weight of the castings must be appropriate; the batches should be satisfied; and the time limit for completing the production task should be agreed.