CN2767993Y - Clamp for testing high temperature tensile property of thin-walled pipe - Google Patents

Abstract

A fixture for testing the high-temperature tensile properties of thin-walled pipes, relating to a device for the tensile properties of metal pipes, in particular a fixture for testing the high-temperature tensile properties of thin-walled pipes (with a wall thickness less than 2mm) for full-pipe specimens. Its structure includes the main splint of the fixture, the auxiliary splint of the fixture, the bolts pass through the main splint and the auxiliary splint, and are connected by nuts. The utility model solves the phenomenon that the sample slips and breaks at the root during the high-temperature tensile test of thin-walled pipes, and the fixture and the sample can be put into the heating furnace for heating at the same time, reducing the length of the sample. The temperature gradient makes the test results more accurate and reliable.

Description

A jig for testing the high-temperature tensile properties of thin-walled pipes

technical field

A fixture for testing the high-temperature tensile properties of thin-walled pipes, relating to a device for the tensile properties of metal pipes, in particular a fixture for testing the high-temperature tensile properties of thin-walled pipes (with a wall thickness less than 2mm) for full-pipe specimens.

Background technique

At present, when performing high-temperature tensile tests on thin-walled pipes, the method of lengthening the length of the pipe sample is often used to make the sample extend out of the heating furnace and connect with the fixture. This clamping method has two defects: 1: It will cause the test The waste of materials increases the test cost. 2: During the test, there will be a temperature gradient in the length direction of the pipe sample, which will cause errors between the test results and the actual performance of the pipe. There is also a conical fixture, which is mainly composed of a conical internal reference and a jacket. There are fine teeth on the contact surface of the conical internal reference and the sample. During the high temperature tensile test, the jacket presses the conical internal reference to change the taper of the internal reference. Thereby, a clamping force is generated on the sample and the biting force of the internal reference upper fine teeth on the sample is used to clamp the sample. This kind of fixture is easy to cause the sample to slip during the test or the sample is broken in the clamping part due to stress concentration, thereby affecting the accuracy of high temperature tensile properties.

Contents of the invention

The purpose of this utility model is to aim at the deficiencies of the above-mentioned prior art, and to provide a method that can effectively overcome the increase in test cost, sample slipping, and test results caused by existing fixtures and clamping methods when testing the high-temperature tensile properties of thin-walled pipes. There are insufficient errors to test the fixture for high temperature tensile properties of thin-walled pipes.

The utility model is achieved through the following technical solutions.

A jig for testing the high-temperature tensile properties of thin-walled pipes is characterized in that its structure consists of:

Fixture main splint - the basic shape of the main splint is a stepped cylinder, in which the detailed part of the cylinder has a pin hole near the end to connect with the tensile test device with a pin, and the thick part of the cylinder is cut off vertically and passes through the axis For the rest of the cylinder, the axis of symmetry of the fixture is the center of the circle, and there is a cylindrical groove that is basically consistent with the outer diameter of the test pipe in the tangent surface of the cylinder; There are bolt through holes;

Auxiliary splint of the fixture—the auxiliary splint is shaped like the main splint column, which is vertically cut off from the thick part of the main splint, and has the same shape as the part passing through the axis, and has a cylindrical groove with the same shape as the main splint; outside the groove The column body is provided with a bolt through hole intersecting with the bolt through hole of the main splint;

Fixture fastening bolts—the bolts pass through the main splint and the auxiliary splint, and are fastened by nuts to connect them.

The utility model can realize the miniaturization of the size of the fixture without affecting the use effect of the fixture, so that the fixture and the sample can be put into the high-temperature furnace for heating at the same time, thus reducing the temperature gradient in the length direction of the sample and making the The experimental value is closer to the real value. The contact surface between the fixture and the sample clamping part is a circular arc surface, thereby reducing the stress concentration of the sample clamping part, and the sample will not be broken in the clamping part during the high temperature tensile test. Moreover, in the high-temperature tensile test, the tensile strength of the pipe is low, and the cross-sectional area of the thin-walled pipe is small, so the breaking force is correspondingly small. Therefore, only the friction between the fixture and the sample can guarantee the test There is no slippage phenomenon. The utility model solves the phenomenon that the sample slips and breaks at the root during the high-temperature tensile test of thin-walled pipes, and the fixture and the sample can be put into the heating furnace for heating at the same time, reducing the length of the sample. The temperature gradient makes the test results more accurate and reliable.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Fig. 2 is a structural schematic diagram of the clamp main splint of the present invention.

Fig. 3 is a schematic diagram of the structure of the sub-splint of the clamp of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described as follows.

A fixture for testing the high-temperature tensile properties of thin-walled pipes, which is characterized in that its structure is composed of: fixture main splint 3 - the basic shape of the main splint is a stepped column, wherein the detail of the column has a pin hole near the end 9 It is connected with the tensile test device 1 with a pin 2. The thick part of the cylinder is the remaining cylinder after cutting off the vertical part and passing through the axis. There is a cylindrical groove 4 that basically coincides with the outer diameter of the test pipe; there is a bolt through hole 8 on the cylinder outside the groove; the auxiliary splint 5 of the fixture—the auxiliary splint is shaped as the thick part of the main splint cylinder Cut off the part that is vertical and has the same shape as the axis, and open a cylindrical groove 4 that is symmetrical to the main splint; Holes; fixture fastening bolt 6—the bolt passes through the main splint and the auxiliary splint, and is fastened by nuts to connect them.

The hole diameter of the sample hole of the cylindrical surface groove of the utility model is the same as the outer diameter of the pipe to be tested, but a part is cut along the horizontal direction at the center, and the fixture is divided into a set of two pieces. When carrying out the thin-walled high-temperature tensile test, after the two ends of the pipe sample 7 are fitted with pins on the pin holes, the head of the sample is put into the sample hole, so that the head of the sample is placed on the rear wall of the hole, and the bolts Bolts are installed in the holes to fasten the main splint and the auxiliary plate, connect the fixture and the testing machine with pins through the pin hole, then put the fixture and the sample into the heating furnace, and wait for the sample to reach the set value. After a certain temperature, the high temperature tensile test can be carried out.

Claims (1)

1. A fixture for testing the high-temperature tensile properties of thin-walled pipes, characterized in that its structure consists of: Fixture main splint - the basic shape of the main splint is a stepped cylinder, in which the detailed part of the cylinder has a pin hole near the end to connect with the tensile test device with a pin, and the thick part of the cylinder is cut off vertically and passes through the axis For the rest of the cylinder, the axis of symmetry of the fixture is the center of the circle, and there is a cylindrical groove that is basically consistent with the outer diameter of the test pipe in the tangent surface of the cylinder; There are bolt through holes; Auxiliary splint of the fixture—the auxiliary splint is shaped like the main splint with the thick part of the main splint cut off vertically and the part passing through the axis has the same shape, and a cylindrical groove with the same shape as the main splint is opened; outside the groove The column body is provided with a bolt through hole intersecting with the bolt through hole of the main splint; Fixture fastening bolts—the bolts pass through the main splint and the auxiliary splint, and are fastened by nuts to connect them.

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