Centrifugal casting process

Metal filter, pouring temperature, casting speed, spraying use, take off casting, gating system, quantitative pouring, they are all necessary to determine or solve process problems in the production of centrifugal casting, because it directly affects the casting quality and production efficiency.

Metal filter

There are some residual difficult to remove in alloy liquid, put all kinds of filter to remove residual in gating system, such as foam ceramic filter and glass filter.

Pouring temperature

Most of centrifugal casting are tubular, set, ring parts, So  the liquid metal filling encounter less resistance, in the meanwhile centrifugal pressure or centrifugal force to strengthen the liquid metal filling ability.

Casting speed

The speed of casting is an important technological factor of centrifugal casting, when the casting and the casting process is different, the speed is different either.

Low casting speed can make the vertical centrifugal casting filling insufficiently, and the horizontal centrifugal casting appearing in the metal rain. In the meanwhile the casting will be in osteoporosis ,slag and the casting surface will be defect with concave and convex inequality .

If the casting’s speed is too high, the casting will be in defects with  crack and segregation, The surface of Centrifugal casting sand mold will form defects such as expanding box and make the machine enlarge vibration ,wear and power consumption. So the selection principles of casting speed should select the smallest value on the premise of guarantee the quality of castings.

The use of slag

To overcome the thick wall centrifugal casting’ defect of subcutaneous shrinkage cavity caused by Bi-directional solidification, we can pour the slag former with metal into type when pouring, The slag coverage within the casting’ surface which prevent heat dissipation from inner surface. Forming the cooling condition out-to-in, it can eliminate subcutaneous shrinkage cavity. In the meanwhile slag former can also be refined metal.

The way of pouring slag former: when pouring we can put powdery slag former into Pouring trough, which let molten slag into type with liquid metal.

The use of coating

The composition coating of centrifugal metal mold is similar with gravity metal mold. When pouring thin centrifugal casting, Due to remove residual coating on the surface of the mold is difficult, so the binder which is in the coating should be low residual strength after work in high temperature. It can be easy to clean up.

Gating system

Centrifugal casting gating system is made up with pouring cup, casting trough and pouring gate in the mold. When designing gating system, we should pay attention to the following principles:

1.When pouring the casting of long and large diameter, The gating system should make the metal liquid spread on the inner surface of the mold rapidly and uniformly.

2 When pouring , the pouring gate inner mold should be able to make metal liquid flows into the cavity smoothly;

3 After pouring, The pouring cup and pouring gate shouldn’t have metal and slag. If there are any residual metal and slag ,we should be easy to remove.

Quantitative pouring

The diameter of centrifugal casting is decided by the number of casting metal. So when pouring, we must control the number of metal pouring into the type to ensure the inner diameter size. In the production application, pressure sensor is installed in the casting ladle shelf, which ensure quantitative pouring automatic in centrifugal casting and Induction furnace electromagnetic pump .

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