JPH07104241B2 - High temperature creep test equipment for ceramics and high temperature creep test method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a high temperature creep test apparatus and a high temperature creep test method used, for example, in testing the bending creep properties of ceramics.

[Prior Art] As is well known, it is extremely important for practical use to carry out a creep test in which the stress applied to a test piece is kept constant and the degree of deformation at high temperature is measured to determine the creep properties of high temperature structural component materials. Also, it is indispensable in designing parts.

Even in ceramics having excellent heat resistance, at high temperature, if stress is applied for a long time, deformation and subsequent destruction occur.
Therefore, when applying ceramics to high-temperature strength parts, it is necessary to design in consideration of creep deformation and creep rupture strength.

Conventionally, in the creep test of this ceramic,
For example, the test apparatus shown in FIGS. 7 and 8 was used.

The test apparatus shown in FIG. 7 comprises a furnace section 1 for accommodating a test piece therein, and a load section 2 for applying stress to the test piece in the furnace section 1. Further, as shown in FIG. 8, the test piece 3 is placed on the knife edge 4, and stress is applied to the test piece 3 from the load section 2 via the upper load jig 5 and the alumina tube 6. . Further, an alumina rod 7 is inserted into the alumina tube 6, and the alumina rod 7 is
The dial gauge 8 is engaged with.

Further, the knife edge 4 is installed on the base 9 in the furnace section 1.

According to the above-described conventional creep test apparatus, the test piece 3 on the knife edge 4 in the furnace part 1 is loaded with the load part 2 under high temperature.
Four-point bending stress is applied via the upper load jig 5,
The resulting deformation of the test piece 3 is indirectly measured by the dial gauge 8 as the displacement of the alumina rod 7.

Further, there is also known a device in which a plurality of test pieces are arranged in a furnace and tested simultaneously in order to improve the efficiency of measurement.

[Problems to be Solved by the Invention] However, the above-described conventional creep test apparatus has the following problems.

That is, in the above-mentioned creep test device, a plurality of test pieces are arranged in one furnace to perform the test,
In conducting a new test, it was necessary to lower the temperature of the furnace, set the test piece 3 in the furnace section 1, then raise the temperature in the furnace section 1 and start the test.

In this way, in the conventional creep test device that uses one furnace for a plurality of test pieces and raises and lowers the temperature of the furnace for each measurement,
Since it is necessary to lower the temperature in the furnace and raise the temperature each time a test is performed, the heat in the furnace cannot be used effectively, and the temperature raising / lowering process requires time, and all test pieces in the furnace There was a problem that the test pieces could not be exchanged until the measurement of 1 was completed and a waiting time was required, resulting in poor efficiency. The creep test is
Since the measurement is performed for a long time such as 1000 hours, improving the efficiency of the test equipment has been an important issue.

Therefore, the present invention solves the above problems in the conventional creep test apparatus, provides a highly efficient creep test apparatus that can effectively utilize the heat in the test furnace and save time. The purpose is to

[Means for Solving the Problem] According to the present invention, the above object is to perform a test in which a furnace body (11) having a plurality of test piece insertion ports (31) and one test piece (27) are placed. The piece placement base (24) and the test piece placement base (24) are supported, and the test piece placement base (24) is inserted into the furnace main body (11) through the test piece insertion port (31). It can be achieved by a high temperature creep test apparatus for ceramics, characterized in that it has a plurality of supporting means (14) having a drive unit (18) for individually inserting and removing the test pieces (27) in the vertical direction.

Further, according to the present invention, using the above-mentioned high temperature creep test device, while maintaining the furnace (11) at a predetermined test temperature,
Only the test piece (27) that has completed the test is a new test piece (27).
And a high-temperature creep test method for ceramics, in which a predetermined creep test is performed.

[Operation] According to the creep test apparatus and the creep test method of the present invention, it is possible to store a plurality of test pieces in the furnace body and perform the test simultaneously, and some of the test pieces are deformed by a predetermined amount or broken. In that case, if only a part of the test piece is taken out of the furnace and a new test piece is stored in the furnace to start the test, it is not necessary to raise or lower the temperature in the furnace at that time. Meanwhile, the other test pieces can be continuously tested.

Further, it is preferable to install a strain measuring device for measuring the strain of the test piece on the supporting means, since the arrangement state of the strain measuring device on the test piece can be confirmed outside the furnace. Furthermore, the strain measuring device is preferably a direct strain measuring device capable of measuring the strain of the test piece as a direct change, because the error due to thermal expansion due to the temperature in the furnace is smaller than that of the indirect strain measuring device.

It is preferable to install a temperature measuring device such as a thermocouple for measuring the temperature of the test piece on the supporting means, because the temperature of the test piece can be accurately measured because it can be measured in the closest vicinity of the test piece or in contact with the test piece. it can.

If the driving speed of the supporting means is adjustable, the temperature change in the furnace body can be reduced when the supporting means is inserted into or removed from the furnace body, which is preferable.

Further, it is preferable to install an opening / closing lid at the test piece insertion port, which is interlocked with the driving of the supporting means, which is opened when the supporting means is inserted into the furnace main body and closed when the supporting means is detached from the test piece insertion port. Further, it is preferable to install a plurality of temperature measuring devices in the furnace body separately from the measurement with the test piece and control the temperature in the furnace body for each zone because the temperature in the furnace body can be easily kept uniform.

It is also possible to perform the test by controlling the temperature inside the furnace body, the drive and drive speed control of the test piece support means, the measurement of the strain amount of the test piece, and the opening / closing of the opening / closing lid of the test piece insertion opening by a computer.

[Examples] Hereinafter, the present invention will be described in more detail based on the illustrated examples, but the present invention is not limited to these examples.

1 to 5 show a creep test apparatus according to an embodiment of the present invention.

In FIGS. 1 and 2, an electric furnace 11 is placed on the electric furnace base 10, and the electric furnace base 10 further comprises a load means 12
It is placed on the base 13a of the support frame 13.

A plurality of test piece support means 14 are attached to the lower part of the electric furnace 11. This test piece support means 14 is a vibration-proof rubber.
It is installed on the base 13a via the base 15.

Above the test piece support means 14, via the electric furnace 11,
The test piece pressing portion 16 of the load means 12 is provided at a position corresponding to each test piece supporting means 14. Also, this test piece retainer
A louver window 17 is provided on the electric furnace 11 between the test piece supporting means 14 and the test piece supporting means 14.

As shown in FIGS. 3 and 4, an elevating motor 18 is attached to the base end of the test piece supporting means 14, and the screw rod 19 driven by the elevating motor 18 is a strain measuring device support base.
A strain detecting device 21 which is engaged with the strain measuring device supporting base 38 and on which the differential transformer 20 can be seen is attached on the strain measuring device supporting base 38.
Further, a slide bearing 22 is attached to the strain detector supporting base 38, and the slide bearing 22 is attached to a guide column 23 so as to be vertically movable. further,
A position sensor 40a for sensing the position of the strain measuring device support 38,
40b and 40c are attached.

A test piece mounting base 24 is mounted on the strain detecting device 21 via a water cooling cylinder 35, and the test piece is placed on the test piece mounting base 24.

As shown in FIG. 5, a test strip holder 25 is mounted on the test strip mounting base 24. This test piece holder 25
Notches 25a and 25b are formed on the upper side, and the notches 25a and 25b are formed.
Push pins 26a, 26b are locked to the. Its push pin 2
The test piece 27 is placed on 6a and 26b, and the test piece 27
The upper load jig 28 is placed on the upper part, and
28 A holding jig 36 is placed on the upper part. This holding jig 36
On the other hand, the tip end of the push rod 29 of the load device is abutted against.

As shown in FIG. 3 and FIG.
By the inside, and each of the test piece support means 14 into the furnace into each insertion port 31, the test piece support means 14 into the furnace,
An opening / closing lid 32 is provided that automatically opens and closes according to the detachment.

In FIG. 5, the strain detecting rods 33a, 33b are placed at their tips in contact with the test piece, and the hollow portion of the test piece receiving base 25 and the hollow portion of the test piece mounting base 24 are taken to engage the upper portion of the strain detecting device 21. Have been combined. Similarly, the tip of the thermocouple 34 is placed in contact with the test piece, and the hollow portion of the test piece receiving base 25 and the test piece mounting base 24
Through the hollow portion of the above and is connected to a temperature measuring device (not shown).

According to the creep test apparatus of the present invention described above, the creep test is performed as follows.

First, various test pieces having different properties such as components and densities are placed on the test piece mounting base 24 on each test piece supporting means 14 and the temperature inside the electric furnace 11 is raised.

Next, the test piece support means 14 is raised by the elevating motor 18 and the test piece 27 is inserted into the electric furnace 11. When the temperature reaches a predetermined temperature, a predetermined stress is applied to each test piece 27 from the push rod 29 of the load device via the upper load jig 28.

Then, after a predetermined time has elapsed, or when any one of the test pieces is deformed or ruptured, the test piece support means 14 equipped with the deformed test piece 27 drives the lifting motor 18 to drive the test piece. The mounting base 24 is lowered. that time,
At the same time when the test piece mounting base 24 and the test piece are removed from the electric furnace 11, the opening / closing lid 32 is closed and the inside of the furnace is kept at a constant temperature.

Next, the deformed test piece on the test piece mounting base 24 separated from the electric furnace 11 is replaced with a new test piece, and the test piece mounting base 24 is inserted again into the electric furnace 11. Meanwhile, the other test pieces are continuously tested. With respect to the test piece newly inserted into the furnace, the creep test under a predetermined temperature can be immediately continued by applying stress from the push rod 29.

Further, after arranging the test piece 27 on the test piece mounting base 24 on the test piece supporting means 14, the temperature control of the electric furnace 11 and the raising and lowering of the test piece supporting means 14 are carried out by using the automatic measuring system shown in FIG. The motor 18 is moved up while adjusting the speed so that the temperature inside the furnace does not change, the opening / closing lid 32 is opened, and the test piece 27 is inserted into the electric furnace 11. Further, after the thermocouple 34 senses a predetermined temperature, a predetermined load is applied by the load means 12 to measure the strain amount of the test piece 11. Thereafter, a predetermined amount of deformation or breakage of the test piece 27 is detected by the strain detection device 21, and the test piece support means 14 is lowered by the elevating motor 18 while adjusting the speed so that the temperature in the furnace does not change, and the open / close lid is opened. By controlling the closing of 32 by a computer, the restraint time involved in the measurement is reduced.

[Effects of the Invention] As described above, according to the high temperature creep test apparatus and the high temperature creep test method of the present invention, a creep test can be simultaneously performed on a plurality of test pieces, and some of the test pieces are broken. In such a case, only the test piece can be exchanged, and the creep test can be continued for the other test pieces, so that the time required for measuring other test pieces can be saved. Moreover, when replacing a test piece that has been broken or the like and starting a creep test for a new test piece, it is not necessary to raise or lower the temperature in the furnace, and it is possible to always maintain a constant temperature in the furnace. It is possible to effectively use the heat of the furnace, save the cost, and save the temperature rising / falling time in the furnace. Further, after the test piece is set, automatic measurement is performed by the computer, so that the time required for restraint involved in the measurement can be shortened.

[Brief description of drawings]

FIG. 1 is a front view of a creep test apparatus showing an embodiment of the present invention, FIG. 2 is a view taken along arrow A of FIG. 1, and FIG. 3 is a partially enlarged view of the test apparatus shown in FIG. Is the view B in FIG. 3 and FIG.
The figure is a partially enlarged sectional view showing a state in which a four-point bending test of ceramics is performed by the creep test apparatus shown in FIGS. 1 to 4, and FIG. 6 is a diagram showing an automatic measurement system by a computer. . FIG. 7 is a front view of a conventional creep test device, and FIG. 8 is a side sectional view of the device of FIG. 10 …… electric furnace bed, 11 …… electric furnace, 14 …… test piece supporting means, 16 …… test piece holding part, 18 …… lift motor, 25 ……
Test piece cradle, 28 …… Upper load jig, 31 …… Insertion port, 39
...... Water cooled cylinder.

Claims (3)

[Claims] 1. A furnace body (11) having a plurality of test piece insertion ports (31), a test piece mounting base (24) on which one test piece (27) is mounted, and this test piece mounting base. Supporting (24),
The test piece mounting base (24) is provided in the furnace body (11) through the test piece insertion port (31), and a drive device (18) for individually inserting and removing each test piece (27) in the vertical direction is provided. A high temperature creep test apparatus for ceramics, comprising a plurality of supporting means (14). 2. The high temperature creep test apparatus according to claim 1, wherein a strain measuring device (21) is installed on the supporting means (14). 3. A new test piece (27) containing only the test piece (27) that has been tested using the high temperature creep test apparatus according to claim 1 while maintaining the furnace (11) at a predetermined test temperature. High-temperature creep test method for ceramics, which is replaced with the specified creep test.