Not only the shipbuilders there is a need for one-time, single steel casting of certain parts. In these cases, existing technology has to pre-make a wooden model to receive the outdoor imprint in the mold and core boxes for the formation of internal cavities of the casting. The complexity of manufacturing of model kits three to five times higher than the complexity of manufacturing of the castings.
To reduce it, and reduce the cost of a single steel casting innovators Kravchenko, Mikhail Bryzgalov, V. Vidic offered to do the model is not made of wood and Styrofoam. You do not need to extract the model from the mold before pouring, since under the action of hot metal, the foam is converted to a gaseous state and “evaporates” through the pores and holes form.
New casting method from alloys of ferrous and non-ferrous metals at the Styrofoam models has other benefits. This material is easily molded, and therefore, it is possible to obtain castings of complex configuration. The ability to “evaporate” allows you to make form one piece, and this, in turn, almost 30% reduces the amount of chipping and grinding works.
In the mold — “promodel”:
1 — EPS model; 2 — a; 3 — gazovikami hole; 4 — hole injection; 5 — liquid metal.
The complexity of the moulding and core operations reduced by 50%, while manufacturing these casting models in two and more times. Add to this that the Styrofoam is not in deficit and half to two times cheaper than wood.
Important his dignity and that he did not shrink, does not swell from moisture. This eliminates the warping of the patterns and core boxes for transport and storage especially.
The new process allows in many cases to abandon separately manufactured and installed in the form of sand cores: they are used only to perform small horizontal holes.
The introduction of the foam models in the foundry on a single enterprise provides an economic effect of about 30 thousand rubles per year.