CS239672B1 - Equipment for testing metal samples - Google Patents

Abstract

The solution relates to a device for testing samples exposed to temperature and mechanical stress depending on time in natural and artificial protective atmospheres and in vacuum in order to determine these parameters for phenomena occurring in the surface layers of the material. The device consists of a laboratory furnace formed by a vertically placed retort, in which a fixed bed for storing the sample is placed, as well as a pressure jaw connected to a source of mechanical stress, according to the invention. The essence of the solution lies in the fact that the retort 1 is provided with current leads & for direct passage of current and its internal space is connected to a source of protective atmosphere or vacuum, while the pressure jaw £ is at least one and is arranged vertically to slide and rotate.

Description

(54) Equipment for testing metal samples

The invention relates to a device for testing samples subjected to temperature and mechanical stress versus time in a natural and artificial protective atmosphere and in a vacuum to determine these parameters for phenomena occurring in the surface layers of the material. The apparatus consists of a laboratory furnace consisting of a vertically mounted retort in which a fixed bed for receiving the sample is placed, as well as a pressing jaw connected to a source of mechanical stress according to the invention. The principle of the solution consists in that the retort 1 is provided with current inlets for direct current passage and its inner space is connected to a source of protective atmosphere or vacuum, wherein the pressing jaw is at least one and is arranged vertically sliding and rotatable.

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The invention relates to an apparatus for testing metal samples subjected to temperature and mechanical stress depending on the Sax in a natural and decayed protective atmosphere and in a vacuum to determine the effect of these parameters on the phenomena occurring in the surface layers of the material.

Currently, similar tests are carried out in conventional laboratory chamber furnaces. The test specimens are placed in the furnace jaws in the jaws of the jaws and the mechanical stress, e.g., pressure, is usually counterbalanced by a screw connection pulling the jaws of the jaws towards each other. When performing the tests in this way, where the sample and the preparation have to be removed from the furnace, it seems to be a disadvantage that the defined initial mechanical stress condition changes during the test due to thermal dilatations and relaxation of both the preparation and the sample without influence.

The possibility of identifying the state of stress during the test is very difficult. In examining some of the problems in the surface layers of materials, the existing equipment did not give results consistent with practical knowledge due to the impossibility of accurately controlling the mechanical stress during the test.

These disadvantages are overcome by a metal sample testing device consisting of a laboratory furnace consisting of a vertically mounted retort, in which a fixed sample receiving bed is placed, as well as a pressing jaw connected to a source of mechanical stress according to the invention.

SUMMARY OF THE INVENTION The retort is provided with current leads for direct current passage and its interior is connected to a source of protective atmosphere or vacuum, wherein the pressure jaw is at least one and is vertically displaceable and rotatable.

An advantage of the device according to the invention is that the vertically displaceable and rotatable jaw or jaws are subjected to a precisely defined and controlled mechanical stress during the test, by simple pressure, a combination of pressure-shear, pressure-torsion and tension-shear, environment and time.

The attached drawing shows a diagram of an exemplary embodiment of a device according to the invention for a combination of pressure-torsion stresses.

The device consists of a retort χ heated by a direct current passage, which is provided with a lower wolf i and an upper lid χ. A natural or artificial protective atmosphere or a protective atmosphere was introduced into the retort 6 through the inlet 4J. used to vacuum space. The fixed bed at the bottom of the retort J. holds samples 12 ·

Above the fixed bed 1, there is a vertically displaceable and rotatable clamping jaw on the bar 1 exerting mechanical stresses exerted by the mechanical stress applying device. From the controllable power supply by means of the current supply 6, the current is fed to the amplified upper and lower portions of the retort.

A fixed bed X located in the retort X is loaded with 6 pieces of annulus 12 taken from a cold-rolled deep-drawn steel strip to a thickness of 0.5 mm. Controlled compressive and torsional stresses for 1 hour are induced on samples 10 at a temperature of 630 ° C and under a nitrogen atmosphere N _{2 of the} pressure jaw &.

Over the next 4 hours, the temperature dropped at 150 ° C / h ^-1 under the stress conditions. After the test, the surface roughness condition, susceptibility to diffusion welding and baking, etc. are evaluated on samples 12.

The apparatus for testing the temperature and mechanical stress versus time stresses of the present invention may be used, for example, to simulate the behavior and conditions of the surface layers of the individual coils of the cold rolled strip during subsequent heat treatment in the coil, e.g.

Claims (1)

SUBJECT OF THE INVENTION Device for testing metal specimens, consisting of a laboratory furnace consisting of a vertically placed retort, in which a fixed bed for storing the sample is placed, as well as a clamping jaw connected to a source of mechanical stress, characterized in that the retorto (1) is provided with current leads (8) for direct current passage and its interior space is connected to a source of protective atmosphere or vacuum, wherein the pressing jaw (6) is at least one and is arranged vertically sliding and rotatable.