SU822970A1 - Pickup preventing paint for casting moulds and cores - Google Patents

Description

(54) ANTI-GRINDING PAINT FOR CASTING FORMS AND RODS

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FIELD OF THE INVENTION The invention relates to a foundry, namely, a composition of non-stick paints for casting molds and cores.

Nonstick-based paints based on various refractory fillers containing bonding materials and stabilizers are known, contributing to the stability of fillers in the sprayed media. In this case, a sulphite-yeast brew (SDB) is used as a binder, and bentonite D- is used as a stabilizer.

Closest to the invention of the technical essence and the achieved result is anti-burn paint, vtachacada refractory filler (cryptocrystalline graphite), organic bonding (sul1) yeast mash) bentonite and water

However, the paint does not have a sufficiently high poor input resistance and does not always provide a high-quality surface of iron castings.

The purpose of the invention is to improve the quality of the surface of iron castings and increase the sedimentation stability of the paint.

The goal is achieved by the fact that the paint, including the refractory filler, organic binder, bentonite and water, also contains shale powder in the following ratio of ingredients, wt.%: Refractory filler 50, 0-53.0 Organic binder 6, 0-10.0 Bentonite . 2.0-4.0 Slate powder 2.0-10.0 Water Else As a fireproof filler, the dye contains cryptocrystalline graphite, pyrophyllite or shungite. As an organic binder, the dye contains sulphite-yeast bligku, dextrin or molasses.

Shale powder consists of 35-55% organic matter and 45-65% mineral substances (Si 0 25.26; AljOj 6.47; RvdO5 5.43; CaO 44.94; MdO, 93; 50 7.85; K, 2P 2.19; Na / iO 0.3; 0.19; Ti04-0.5 and pp 0.48%).

Slate is easily ground in any aggregates used for grinding lumpy materials — ball mills, jet grinding plants, Katkov runners, etc. The slate powder used in the paint composition has a specific surface of 700-1000 cm / g, which corresponds to its dispersity of 0.16-0.05 m. In tab. Table 1 shows the compositions of the paint to be offered. In tab. Figure 2 shows the properties of the edge of compositions 1–4. The mineral substances that make up the paint have a high swelling capacity, which makes it possible to form a stable spatial structure of the nonstick paint. The deterioration of the surface quality of cast iron castings produced in the stained forms with the proposed countering paint is explained by the fact that the slate powder contains up to 35-55% of organic matter, which decomposes under the influence of temperature in the metal form, releasing a significant amount of pyrocarbon. The thinnest film of pyrocarbon formed on the surface layer of the cavity is practically not wetted by liquid metal, and thus interferes with the interaction of metal oxides with the mold material, i.e. helps to eliminate casting burner and improve surface quality.

Graphite Sedimentation stability,% Durability on is2, 4-2,7 1,14-1,96 1,0 tiraniye, kg

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Claims (2)

Table 2 98-99 The optimum amount of shale powder is 2.0-10.0%. At the same time, an increase in shale powder in excess of 10.0% does not lead to a noticeable increase in paint stability, but contributes to an increase in its gas-creation, which negatively affects the formation of a high-quality surface of the casting. In addition, the use of shale powder within the specified limits in paint compositions based on talc and pyrophylitum eliminates the bright-colored patches on the surface of castings, which are the product of thermal transformations of these fillers that occur when casting forms with cast iron. The paint is prepared as follows. A binder (ADD) and water are poured into the mixer, and mixed for 2-3 minutes, after which the refractory filler, bentonite, and shale foam are loaded. The mixing process is continued for another 12-15 minutes until a homogeneous suspension with a density of 45 g / cm is obtained. Applied by painting or dipping on the surface of the mold or rod, the paint layer is dried at 150-200 C for 40-60 minutes. The proposed nonstick paint has increased sedimentation stability and provides for obtaining iron castings with improved surface quality, i t a b l c i 1 1.3.7 0.8–1.07 0.8–1.10 The depth of paint penetration into the mold, mm Roughness The surface of the casting at rccrc The invention claims Nonstick paint for casting molds and cores, including a refractory filler, organic bond, bentonite and water, characterized in that, in order to improve the quality of the surface of chuf-un cast and increase sedimentation the stability of paint, it contains shale powder in the following ratio of ingredients, wt.%: Refractory filler 50-53 Continued table. 2 Compositions 0.2-0.3 130-260 130-140 0.1-0.3 0.1-0.3 120-130 120-130140-160 Organic binding 6-10 2-4 Bentonite 2-10 Shale water Water Rest Sources of information that are taken into account during the examination 1. SP Doroshenko. and others. Polucheotlivok without burn in sand max. M., Mechanical Engineering, 1978, 64, 69i 2. In the same place 127.