PL3753B1 - Core mass for steel castings. - Google Patents

Description

The subject of the present invention is a core which does not have the above-mentioned disadvantages. This core consists of an upper layer entirely of aluminum vapor or also of bodies containing aluminum vapor, with the addition of conventional binders, such as molasses, tar ] or others. A core made in this way has the advantage that it prevents not only sticking of the cast material to the core due to its high pressure resistance, but also the core itself after casting or upon burning of the binder contained therein, it does not show sintering and can be extracted with the simplest tool and even with the hand without difficulty, as experience has shown. This is a great advantage, for the sake of the health of the workers engaged in cleaning the castings. The tests performed have shown a saving when using these sources, while keeping the castings above 70%. The second advantage is that the mentioned core material, due to its long Compatibility can be used almost constantly after adding only fresh binder. Further attempts to obtain greater strength of the core after forming, relatively dry the core, and greater porosity to facilitate the outflow of harmful gases, showed the effectiveness of adding a mixture of lime and clay. It is also possible to replace aluminum nitrides and bodies containing this compound in a complete mixture of lime and clay, which has the greatest refractoriness and does not contain harmful additives. By using a mixture of lime and clay, a better bonding of the core is obtained after the formation of the stick, relative to drying, a greater porosity of the core, allowing for better drainage of harmful branch, and easier removal of the core from the finished casting. PL

Claims (3)

Patent claims. 1.The core for the production of smooth steel castings, especially hollow ones such as molds, valve seats, pump housings and other machine parts, characterized by a shell that consists entirely of aluminum nitride or bodies containing aluminum nitrides with the addition of ¬ forests, tar or other common binders. 2. The core according to claim 1, the alternative is that a mixture of lime and clay is added to the gliitou nitride or the aluminum nitride containing clay. 3. The core according to claim The method of claim 2, wherein the aluminum nitride or the bodies containing aluminum nitride are replaced by a mixture of lime and clay. Eckert, Oppelt & Cie. G. m. B. H. Zastepca: M. Kryzan, patent attorney. Print by L. Boguslawski, Warsaw. PL