SU1474146A1 - Method of moulding elastic refractory articles - Google Patents

Abstract

The invention relates to the production of refractory materials and can be used for the manufacture of refractory products of complex shape, for high-temperature vacuum seals in metallurgy, mechanical engineering, chemical industry. The invention is directed to fixing the shape of a deformed product and increasing strength. The goal is achieved by the fact that, in the method of forming elastic refractory products, including the preparation of the mixture and its shaping under pressure, the profiled product is additionally processed with γ-radiation before absorbing a dose of 50-750 kGy. The method allows to increase the strength of the products by 1.5-2 times and fix the shape of the products under which the irradiation was performed. The product after processing retains its elasticity. 2 tab.

Description

one

The invention relates to the production of refractory materials and can be used for the manufacture of products of complex, curved shape, for high-temperature vacuum seals in mechanical engineering, in ferrous and nonferrous metallurgy, in the chemical industry.

The aim of the invention is to fix the shape of the deformed product and increase the strength.

Example 1. SKN-40 rubber (5 parts per hour) and Nairit-A rubber (4 parts per hour) are loaded into a roll gap of 1.2 mm and 9 parts by weight of fused corundum fraction are introduced and mixed for 3 minutes 0-0.25 mm. Then 1 math is introduced. liquid oligomer. CKN-18-1 and the remaining 80 ma.h. fused corundum. Stirring is continued for 8 minutes with a gap between the rolls of 7 mm. Get the workpiece sheet, which is rolled in the size of the thickness of 0.5 ± 0.1 mm on the exhaust rolls. From a sheet cut elastic tapes 30 mm wide. Products have the following characteristics:

Density, g / cm 3,2

Tensile strength

at stretching, MPa1,8

The resulting tape is wrapped with a tension of 1%, the cylindrical surface of the heat exchanger tube with an outer diameter of 60 mm. The ends of the tape are fixed, then the product is processed by radiation until the dose of 750 kGy is absorbed on the RV-1200 unit. After irradiation, the tape fits the pipe surface tightly and does not need

in fastening. The irradiated tape has the following characteristics: Density, g / cm 3,2 Tensile strength at stretching, MPa3,2 Relative elongation at stretching,% 10 EXAMPLE 2 Analogously to example 1, only the treatment of the product Jr with radiation is carried out before absorbing a dose of 50 kGy. The tape thus treated has the following characteristics:

Density, g / cm 3,2 Strength at stretching, MPa 2,8 Relative elongation at

stretching% 15

After irradiation, the tape fits tightly onto the surface of the pipe and does not need to be fixed.

EXAMPLE 3 A butyl rubber and fused magnesite in a 1: 1 ratio are loaded into a rubber mixer and stirred for 2 minutes, then a liquid oligomer BN-18-1 DR is added and the fused magnesite is mixed and mixed for 5 minutes. The composition of the mixture, wt.%: Magnesite fused 85 butyl rubber 12; oligomer RH-18-1 DR 3. The resulting mixture is placed in a mold and pressed under. pressure of 200 MPa sheet shaped gasket 2.3 mm thick. The material of the product has the following characteristics:

Strength at stretching, MPa 0.8 Relative elongation at stretching,% 4

0

five

After pressing, the product has low strength, which does not allow it to be removed from the mold without destruction. After the treatment of the product by radiation, until a dose of 750 kGy is absorbed, the product material has the following characteristics:

Tensile strength

during stretching, MPa1.6

Relative

elongation at

stretch% 2

This allows the product to be removed from the mold.

Example 4. Three ELOM compositions (Table 1), made by mixing on rollers as in Example 1, are wound in 50 mm wide strips and 5 mm thick on a metal cylinder 50 mm in diameter and are treated with radiation by γ-ray until the dose is absorbed. 300 kGy.

Table 1

After irradiation of the strip, the samples from compositions 1 and 2 retain their shape, the sample from composition 3 does not retain the shape, which is due to the high content of rubber.

Characteristics of the compositions are given in Table 2.

table 2

Strength at stretching, MPa Relative elongation at stretching,%

0.9 1.42 0.3 1.6 1.93 0.5

35

240 j 2J102

35

240 j 2J102

All compositions after irradiation increase the strength by 1.3-1.8 times.

Claims (1)

Invention Formula The method of forming elastic refractory products, including the preparation of the mixture and its shaping under pressure, characterized in that, in order to fix the shape of the deformed product and increase its strength, after profiling, the product is processed by f- - radiation before absorbing a dose of 50-750 gGy