SU628996A1 - Composition for making heat insulation inserts and spacers for casting heads - Google Patents

Description

The invention relates to a foundry, in particular, to compositions of mixtures used for the manufacture of heat insulating inserts and inserts for foundry profits.

Closest to the proposed invention in its technical essence and the achieved result is a heat-insulating mixture containing 60-70 wt.% / O mineral fiber and 30-40 wt.% Liquid glass with a module 2.6 and a density of 1.0-1. 3 g / smz G.

As the mineral fiber in the described mixture, aluminosilicate fiber is used, for example, high-alumina wool.

Such a mixture is characterized by unsatisfactory ability to fill the tooling during the manufacture of heat insulating inserts and inserts. This is due to the large internal friction between the filler — mineral fiber and the binder — liquid glass.

Due to the low flowability of such a mixture, it is impossible to obtain heat-insulating inserts and inserts of a complex configuration with the help of

foundry compaction techniques. In addition, the mixture has an increased thermal conductivity due to the high content of liquid glass.

The purpose of the invention is to improve the ability of the mixture to fill the equipment in the manufacture of heat insulating inserts and inserts and increase its heat insulating properties.

This is achieved in that the mixture, including high alumina wool, water glass and water, contains the indicated ingredients in the following ratio, wt.o: High alumina wool 25-30 Liquid glass5-6

Water 64-70.

Due to the changed ratio of ingredients, it is possible to manufacture thermal insulating inserts and inserts of any configuration without using sealing devices by simply pouring the mixture into core boxes.

When the content of ingredients below the lower limit improves flowability and formability, decreases the coefficient of thermal conductivity. However, with an increase in the water content, the mixture acquires a higher moisture content, the excess of which is more difficult to remove during vacuuming. As a result, the durability of the cheese is reduced and the manufacturing process of the products becomes more difficult. Thus, reducing the content of ingredients is not feasible for technological reasons. When the content of ingredients above the upper limit deteriorates the formability and plasticity of the mixture, the content of liquid glass increases, and the thermal conductivity increases. For the preparation of the mixture, low modulus water glass with a modulus of 2.0-2.2 is used to ensure the required vitality of the mixture. The mixture is prepared as follows. Liquid glass and water are loaded into the mixer, then high-mineral cotton wool is introduced in portions and mixed until a suspension is obtained. Thermal insulating inserts and liners receive, by filling, slip mass in a snap. Excess moisture is removed by evacuating at a vacuum of at least 0.5 mg / cm. The resulting product is subjected to drying at a temperature within 2-5 hours

Table 1 964 Example. To obtain inserts, three mixtures were manufactured according to the present invention (Nos. 1-3) and a mixture according to the selected prototype (No. 4). The mixtures Nos. 1-4 are listed in Table. I. Physicomechanical and thermophysical properties of mixtures No. 1-4 are given in Table. 2. From the table. 2 data shows that the proposed heat insulating mixture has a low thermal conductivity in a wide range of temperatures (600-1100 ° C), which provides products (inserts and liners) with high thermal insulation properties. In addition, in comparison with the heat insulating mixture chosen as a prototype, the proposed mixture is prepared in the form of a suspension, which allows to obtain heat insulating inserts and inserts by pouring it into the tooling. The use of heat: anti-roll inserts and liners made from the proposed mixture reduces the amount of profit by 30-50% for castings of high-strength iron and steel, which saves 10-15 rubles. for 1 ton of good to pour.

Liquid stack is about (density Durability is shorter, 2.42.6 kgf / cm. Refractoriness ° C

Table 2 0.155 O, 235 O, 34 2.85-10 7601500-18OO

5628996e

Claims (1)

The claims of the invented ingredients are as follows for the manufacture of the thermally insulating high alumina cotton 25-30 inserts and inserts for foundry glass with liquid glass 5- b former, including high-aluminaWater 64-70 cotton wool, water glass and water, different - $ so that, in order to improve the abilities, the sources of information taken into account to fill tooling during the manufacture of the examination: inserts and liners and increase heat, G. USSR author's certificate insulating properties, it contains AQ-No 375276, M.kl. C 04 B 43/02, 1-971 carrying components, wt. ° / o: