SU884827A1 - Pickup preventing coating for casting moulds and cores - Google Patents

Description

(54) ANTI-GRUNTING COATING FOR CASTING FORMS AND RODS The invention relates to the drinking industry, in particular to anti-frit coatings of dp casting molds and rods. A nonstick coating is known, which includes manganese chloride and water in a ratio of 1: 1 E. The disadvantage of this coating is the absence in its composition of a material with high heat resistance, which makes it possible to change such coatings only for castings with a relatively small wall thickness of 5-110 mm. Coating j, 2j, conejvzhaschee, wt.h.: Dusty quartz78 Manganese ore8 Binding agent LKBZH (liquid bard foundry concentrate 6 Stabilizer including Bentonite2 Substrate lye6 Water Up to 1.6-1.8 g / sec. However, this coating has insufficiently high heat resistance. The closest to the proposed technical essence and the achieved result is a non-stick coating J for casting molds and cores, containing, wt.h .: Manganese dioxide 12-15 Chromo-magnesite 30-40 Distin-sippimant15-25 5% solution of polvksbtiral in ethyl alcohol 10-20 Oanako, when pouring a mold with metasht, the known coating does not provide the required rate of oxidation of the veins of metaraia, which makes it difficult to form easily separable burns on the surface of the castings. The purpose of the upgraded geni is to ensure the formation of a separable burn on BeiRHocTH castings. In order to achieve this goal, a coating comprising chromomagnesite, disteve (: n and it "1git and popivinilG utn solution) o / 1I in ethanol, additionally solr it and potassium-aluminum alum in the following ratio of ingredients, m / 1s, h:

Potassium-aluminum

alum12-15

Hrs Omagnezkt4O-50

Diet n-sillimanit1O-20

5% solution palivinkbutiral in etypovym

alcohol1O-20

Capium-aluminum alum A KfeCi) at a temperature above 92СРс decomposes with intensive oxygen evolution. The composition of gases during decomposition also includes water vapor, oxidizing the effect of which increases at tempo88 O-9OCf C. The oxidation process is also enhanced when present in gases 50 and 9 O which are released when unzipping alum. Highlight gases O2, SuOp and 9Oz have a high reactivity to iron and increase the oxidation of solid metal veins, which ensures the formation of easily detachable burns on the surface of the castings.

Chromomagnesite has a high heat resistance (more than 18OO C), a minimum thermal resistance of the thermal expansion coefficient, increases the strength of the coating and in the ratio indicated in

according to the invention, provides easy separation of the burn from the stack of castings.

Diste-shshimanite has a high dispersion, (more) and provides a smooth coating.

A 5% solution of polyvinyl butyral in ethyl alcohol is taken as a binder, stabilizer and phase wrench and creates a covering ability of the coating. The compositions and properties of the coating according to the invention are given in table. 1 and 2.

The coating is prepared in the following manner.

5% solution of polyvinyl butyral in ethyl alcohol is washed down into the mixer

(60% of the total), then the bulk components are introduced and transferred to a homogeneous mass. Then the remaining part of the liquid phase is introduced and it is mixed for another 6-8 minutes, after which the resulting coating is ready for use.

The coating is used to color XTS molds and rods. Coloring is carried out with a brush. Forms poured steel 11OG13L. Mass of castings up to 5OO kg, wall thickness 30-50 mm. The frequency class of the cast surface is Ep 300, no burn-on.

The implementation of the invention will improve the quality of the surface of the castings and reduce the amount of cleaning and rubble works, which will ensure an annual economic effect in the amount of 13 thousand rubles.

Table 1

Density, g / cm

Viscosity s

Sedimentary stability,%

Spreadsheets

Claims (3)

1.6-1.8 18-20 85-9 O Coating ability Thermal stability, with high coatings, cut conditional conditional degree Nuleva (Kumannn fugitive easily detachable during embossing) The oxidation rate of metal veinlets, g / cm with Formula of ejection Non-stick coating for casting molds and rods, including chromomagnesite, dytenyl-sillimanite, and solution (polyvinyl butyral in ethyl alcohol, characterized in that in order to ensure the formation of an easily separable piece on the surface of the castings, the coating additionally contains potassium aluminum alum at eduk dem sootnsipenii in ents, parts by weight .: Kalvevo-aluminum kvastsy12-15 Hroms ksagnezit4X5-5 About Continued table. 2 Good 5O Good osha 50 5O 2-3 2-3 Nuleva Leva 0, O067 Diet n-sillimanit10-2 О 5% solution polivish lbutyral in ethyl 10-20 Sources of information taken into account during the examination 1.Valin Yu , P. and Rasul (f. A, M. Okioliteli - new anti-combustible materials. Chel binsk, South Uralskoye publishing house, 1966, p. 62.. 2. Svarika A. A. Coating foundry molds. M., Mechanical Engineering, 1977, p. 78, 3. USSR author's certificate on application no. 2696841 / О2, cl. In 22 SZ / OO, 1978.