SU1231438A1 - Installation for investigating mechanical properties of materials at high temperatures and pressure in corrosive media - Google Patents

Abstract

The invention relates to a testing technique and can be used to study properties, materials at high temperatures and pressures in corrosive environments. The purpose of the invention is to approximate the temperature conditions of the study to the operational ones. The installation contains a hermetic chamber with upper and lower spherical lids. The cavity of the chamber has the shape of a hyperboloid of rotation with the largest diameter at the lower end, on the surface of which a screen in the form of concentric rings is mounted along its axis. The configuration of the cavity of the chamber and the presence of the screen prevents convective movement of the aggressive gaseous medium and promotes heat transfer to the sample by heat conduction through the fixed medium, which reduces heat loss and thereby significantly increases the sample heating temperature and allows the temperature conditions of gas turbines and power plants to be reached. 1 hp ff, 2 ill. i (L S O s 4 00 00

Description

I

The invention relates to testing equipment, in particular, to installations for studying the mechanical properties of materials at high temperatures and pressures in corrosive media, and can be used in the study of materials of gas turbine elements and power plants.

The purpose of the invention is to approximate the temperature conditions of the study to the operational ones.

FIG. 1 shows a diagram of the proposed installation; figure 2 - diagram of the sealed chamber assembly.

The installation contains a base 1 with vertical columns 2 fixed to it, which are rigidly connected to each other by platform 3. At the top of columns 2, a lifting device 4 is installed, connected via cable 5 to a hermetic chamber 6 fixed to platform 3. Geriatich chamber 6 it is equipped with top 7 and bottom 8 covers, the second of which is spherical. In the working cavity A, the chamber 6, having the shape of a hyperboloid of rotation with the largest diameter at the lower edge 8, has active 9 and passive 10 grippers for fastening the test sample 11. Passive gripper 10 is rigidly connected to the upper cover 7, and active gripper 9 is connected through 12, exit out of the chamber 6 through the seal 13, with a loader (not shown). An annular heater installed in cavity A, covering the central part of sample 11, is made in the form of concentrically mounted two annular electrodes 14 and 15 of a refractory metal. The electrodes 14 and 15 are connected to a power source 16, which can be used as a welding generator having a falling volt-ampere characteristic, for example PS-5000 The outer electrode 15 is rigidly fixed with its outer surface to the inner surface of the chamber 6, and the inner electrode 14 is mounted with using the guides 17 and 18, which also perform the functions of the electrical power supply, with the possibility of axial movement. In the wall of the chamber 6 is placed electromagnetic system, made in the form of an electromagnetic coil 19 and

314382

cooled copper core 20 and designed to rotate the electric arc excited between electrodes 14 and 15. On the bottom cover 8 along the axis of chamber 6 a screen is mounted, wavy in the form of a set of concentric rings 21 mounted with a gap relative to each other. The chamber 6 is equipped with a safety valve 22 and is connected to the system 23 for supplying aggressive media through the fitting 24. The installation is equipped with instrumentation 25, designed to maintain

15 of a predetermined temperature and load on the sample 11, as well as the recording of the parameters of the destruction of the sample 11. The installation works as follows.

20

Test sample 11 is secured in grips 9 and 10. With the help of a lifting device 4, lower the top cover 7 onto chamber 6 and seal it. Moving the internal electrode 14, it is installed exactly in the middle of the working part of sample 11. Including the aggressive medium supply system 23, which uses gas, feeds it into chamber 6 and creates a predetermined pressure in it. The voltage is applied to the electromagnetic coil 19, and include a power source 16, as a result of which between the electrodes 14 and 15 an electric arc is excited, which under the influence of the electromagnetic field of the coil 19 begins to rotate, heating the aggressive gas and the sample 11. The heated medium begins to move up. However, the shape of the working cavity A, made in the form of a hyperboloid of rotation with the largest radius at the lower spherical cover 8, impedes the free upward movement of the medium and leads to the formation of a fixed gas atmosphere. The narrow annular slots between the concentric rings 21, the dissecting convective flow, also limit the zone of movement of the flow, contributing to the formation of stagnant zones. As a result of the restriction of the movement of the gas flow of the medium, the heat transfer to the elements of the chamber 6 and the sample 11

35

40

45

thirty

carried out by heat conduction through a stationary medium, which reduces heat loss and allows a significant increase in temperature .3

heating pattern of sample 11. The rotation of the electric arc also contributes to the inhibition of the upward convective gas flow of the medium.

When sample 11 is heated to a given temperature j, corresponding to the operating temperature, a constant load is applied to it and held at it until destruction. On the basis of load and time to failure, the properties of the material are evaluated at high 1; temperatures in corrosive environments.

For rmul ai zo bret en i.

Claims (2)

1. Installation for studying the mechanical properties of materials at high temperatures and pressures in corrosive environments, containing a hermetic chamber with upper and lower lids, the working cavity of which has the shape of a body of rotation, passive and active grips located in the cavity for fastening the test specimen heater designed to cover the central part of the j five 0 5 4384 The sample is mounted outside the chamber by a loader associated with an active gripper, a system for supplying an aggressive medium into the chamber and instrumentation equipment, characterized in that, in order to bring the investigation temperature conditions closer to the operational conditions, the cavity of the chamber has the shape of a hyperboloid of rotation with the largest diameter of the bottom cover, which is spherical, and the installation is equipped with a screen mounted along the axis of the chamber, made in the form of concentric rings, installed with a gap relative to each other on bottom of the camera. 2. Installation under item 1, about tl and - the fact that the heater is made in the form of two concentric ring electrodes of refractory metal, the outer of which is rigidly fixed on the side surface of the chamber, and the inner one is mounted on the top cover with the possibility of axial movement . 18 23 25 / 7