What are the characteristics of coated sand casting

Film sand casting what are the characteristics?

Coated sand is a common casting process in steel casting foundries. Sand the scope of application is also very wide, its process methods are also different, whether to make core or modeling, laminating sand the basic technological requirements of casting are: the heating temperature should be between 200-300 ℃, the curing time is between 30-150s, sand shooting the pressure should be 0.15-0.6Mpa, except for wet manual workers. The specific parameters need to be based on the model, type and core the weight and its complexity, the type of coated sand, etc. are adjusted. The principle of adjustment is: if it is a sand core with a relatively simple shape, it has good fluidity or coarser particle size, you can choose lower the sand shooting pressure, The thin sand core needs to choose a lower heating temperature, when the heating temperature is low, the manufacturer should appropriately extend the curing time, and vice versa.

What are the characteristics of coated sand for steel casting foundries?

1. The fluidity of coated sand is relatively good. The shape and core contour made with it will be very clear, the structure will be compact, and more complex sand cores can be manufactured, for example, cylinder block water jacket core and cylinder head and so on.

2. Film coating sand it has suitable physical strength performance, so it can be manufactured into high strength. The shell core coating sand can also be made into medium-strength hot core box coated sand, and can also be made into non-ferroalloy coated sand with relatively low strength.

3, steel casting foundry used film. Sand sand cores with good surface quality can be cast, and better surface quality of steel castings can be obtained by less or less coating, and the surface roughness can reach Ra = 6.3 ~ 12.5um, the dimensional accuracy can reach CT7 ~ CT9 level.

4. Coated sand has many advantages, and the cast castings have few defects, but the cost of the same coated sand is relatively high, and the energy consumption is relatively large. Core making and during the pouring process, it will produce a pungent smell, and when it is stored for a long time in high temperature or high humidity season, it may also produce problems such as caking.

5. Coated sand has good collapsibility and castings are easier to clean.

6. The sand core has strong moisture absorption resistance and exists for a long time, which is more conducive to storage, transportation and use.

The technology of coated sand in China is in in the middle of the 1950s, it was once stopped when it was 1960s. In the 1980s, due to the demand for products in the machinery industry and the rapid development of industry, it has created higher requirements for the quality of castings in the industry, so it has promoted the rapid development of the production and application technology of coated sand. Film sand since its development, it has become an indispensable casting process for steel casting foundries.