JPH06300678A - Testing apparatus for molten salt corrosion under stress - Google Patents

Abstract

PURPOSE:To test a stress-strain load under a molten salt environment near an actual environment by providing a temperature controller for regulating a temperature of a testing part, a strain loading unit for applying stress-strain to the part and a molten salt holding mechanism for dipping the part in the salt. CONSTITUTION:A test piece 15 is fixed to a tester by upper, lower grab tools 10, 11, a heater 3 is controlled according to a temperature control signal 17 from a temperature regulator 1 by a signal 2 from a thermocouple disposed on outer surfaces of the piece 15 and a protector 12, and a testing part is held at a set temperature of a melting point or more of molten salt. A strain controller 6 outputs a strain control signal 20 based on any of a stress signal 16 from a load cell 4, a strain amount signal 7 from a strain detector (elongation meter) or an operation amount signal 18 of a strain loading unit 8, and controls the unit 8 through a power source 9 thereby to load the strain-stress of set magnitudes to the piece 15. Thus, the stress-strain load test can be executed in a molten salt environment in which the piece 15 is dipped in the molten salt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stress molten salt corrosion test apparatus for applying strain to a test piece in a molten salt environment and inspecting the corrosion state of the test piece or the mechanical properties of the material.

[0002]

2. Description of the Related Art Up to now, there have been strain addition testers at temperatures called high temperature tensile testers and creep testers, and corrosion testers in molten salt environments. There was no device that could perform the strain addition test in.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a test apparatus for performing strain addition test in a molten salt environment in which a test section is immersed in molten salt.

[0004]

The basic constitution of the present invention comprises a temperature control device for adjusting the temperature of a test part, a strain applying device for applying stress / strain to the test part, and a test part immersed in a molten salt. A molten salt corrosion test apparatus under stress, which is provided with a molten salt holding mechanism for performing the above.

In the above, the temperature of the test portion is maintained above the melting point of the molten salt by a temperature control device comprising a temperature control device, a heater and a temperature detector. In addition, a strain-applying device including a test piece holding unit, a strain applying unit including a power unit and a driving unit, and a strain control unit including a strain detector and a stress detector to control the strain applying unit may be used in a rod-like or tubular Hold both ends of the test piece and apply a controlled strain to perform the test. The power unit of the strain applying unit may be hydraulic, or electrically driven by a gear. Furthermore, a test piece is constantly immersed in the molten salt, provided with a molten salt holding mechanism that is a container that holds the molten salt by integrating with the test piece. As a container, consider a container that consists of a half-molten molten salt container that does not have a gap when integrated with a test piece, a container fastener, a seal between containers, and a seal between a container and a test piece. To be

[0006]

The temperature controller controls the heater based on the signal from the temperature detector to keep the test piece and the molten salt at the set temperature. The strain control unit controls the strain applying device based on either the stress signal from the stress detector or the signal of the strain amount from the strain detector to apply a strain or stress of a set magnitude to the test piece. Desirably, the setting of the stress or the magnitude of strain for the strain control unit can be set as a constant function, ramp (constant speed rise or fall), sine wave, etc. as a function of time, and individual movements can be performed. Alternatively, it is programmable so that the combination of actions can be repeated.

The molten salt holding mechanism is attached to the test piece so that the molten salt does not leak, and the test portion is immersed in the molten salt during the test time. Desirably, a molten salt pan is provided at the bottom of the test piece to protect the test device in the event of a leak.

The test piece gripping tool and the protector constitute the ceiling surface, wall surface and bottom surface of the space for holding the test piece and the molten salt. In particular, for the surface in contact with the test environment, by using a superalloy having excellent high-temperature corrosion resistance, it is possible to minimize corrosion caused by splashes of molten salt and steam.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the structure of the temperature control device and strain adding device of the present invention is shown in the flow chart of FIG. The test piece 15 is fixed to the main body of the test apparatus by the upper grip 10 and the lower grip 11. The load cell 4 is provided as a stress detector on the upper side of the upper grip 10, and the stress signal 16 from the load cell is input to the strain controller 6. The strain amount of the test piece is input to the strain control unit 6 as a strain amount signal 7 by an extensometer or as an operation amount signal 18 of the strain load device 8.
The strain control unit 6 controls the strain load device 8 via the power unit 9 by the strain control signal 20 based on any one of these signals 16, 7, and 18, and the strain of the controlled magnitude is controlled by the test piece 15.・ Give stress.

In order to minimize the corrosion caused by splashes of molten salt, steam, etc. around the test piece, a Ni-base superalloy is used for the surface of the upper gripping tool 10 and the lower gripping tool 11 on the test piece side. A cylindrical protector 12 made of a Ni-base superalloy is also installed on the side surface of the piece. Protector 12
It is attached to the upper grip 10 and covers the lower grip 11 to form a wall surface surrounding the test piece.

The temperature controller 1 is a heater 3 arranged around the protector based on a test piece, a molten salt, and a signal 2 from a thermocouple attached to the outer surface of the protector.
Is controlled by the temperature control signal 17 to keep the test portion at a set temperature equal to or higher than the melting point of the molten salt.

An embodiment of the molten salt holding mechanism according to claim 2 of the present invention is shown in FIG. 2 as a part attached to a test apparatus together with a test piece. FIG. 3 shows a plan view of the molten salt container. The molten salt container 13 has a structure that can be divided in half, and is tightened with a tightening fitting 24 composed of bolts, nuts, washers, etc. so that there is no gap, and the surface between the separated containers and the surface in contact with the test piece 15 are made of platinum. The sealing material 14 is used to prevent leakage of the molten salt, and the test portion is immersed in the molten salt in a steady state. Further, in order to ensure the safety of the device, a tray 26 is provided at a portion that comes into contact with the lower grip 11.

An embodiment of the molten salt holding mechanism according to claim 3 of the present invention is shown in FIG. 4 together with an example of a small test piece shape. The small test piece 27 has the same shape as the normal test piece 15 shown in FIG. 2 integrally with the upper and lower adapters 22, and is fixed to the test apparatus by the upper grip 10 and the lower grip 11. The molten salt container and tightening tool 23 also serves as a tightening nut for fixing the small test piece 27 to the adapter.

Test Example 1 Using the Invention STBA2
For a steel material test piece cut out from a pipe material for No. 2, 700 mol.
A tensile test was performed in a molten salt environment at ℃.

Test Example 2 Using the Present Invention: STB42
To steel specimens cut out from the tubular material _{use, V 2 O 5 (85%} ) in a weight ratio as molten salt + Na ₂ SO ₄ (15
%) At 700 ° C., strain ± 0.2%, strain rate 0.01
A fatigue test was carried out in a molten salt environment in which compression tension was repeated at a cycle of mm / sec for 2 hours.

[0016]

Since the apparatus of the present invention has not existed so far, only individual tests can be performed for each factor of the actual environment such as a corrosion test in a molten salt environment and a stress load test at high temperature. However, according to the present invention, a stress / strain load test in a molten salt environment, which is closer to the actual environment, can be performed for the first time.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of the configurations of a temperature control device and a strain adding device which constitute the present invention.

FIG. 2 shows a molten salt holding mechanism, which is the remaining part of the present invention, corresponding to the embodiment of claim 2.

FIG. 3 is a plan view of a molten salt container.

FIG. 4 shows a molten salt holding mechanism corresponding to an embodiment of claim 3.

[Explanation of symbols]

 1 Temperature Controller 2 Signal from Thermocouple 3 Heater 4 Load Cell, 5 Cooling Water 6 Strain Control Unit 7 Strain Signal 8 Strain Loading Device 9 Power Source 10 Upper Grip 11 Lower Grip 12 Protector 13 Molten Salt Container 14 Sealing material 15 Test piece 16 Stress signal 17 Temperature control signal 18 Signal of operation amount of strain load device 19 Power 20 Strain control signal 21 Tightening nut 22 Adapter 23 Molten salt container / fastening tool 24 Tightening fitting 25 Extensometer 26 Molten salt saucer 27 Small test piece

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tetsuo Ishizuka 20-1 Shintomi, Futtsu-shi, Chiba Nippon Steel Corporation Corporate Technology Development Division

Claims (7)

[Claims] 1. A temperature control device for adjusting the temperature of a test part, a strain applying device for applying stress and strain to the test part, and a molten salt holding mechanism for immersing the test part in a molten salt. Equipment for testing molten salt corrosion under stress. 2. A pair of half-divided molten salt containers having a hole equivalent to the outer circumference of the test part when the molten salt holding mechanism is combined, and a fastener and a container for mounting the container around the test part of the test piece. The molten salt corrosion testing device under stress according to claim 1, wherein the device is composed of a sealing material between the test piece and the container. 3. The molten salt corrosion testing apparatus under stress according to claim 1, wherein the molten salt holding mechanism is composed of a molten salt container which is also used as a fastening tool of an adapter for fixing the test piece. 4. The temperature control device comprises a thermocouple, a heater, and a temperature controller, as set forth in claim 1.
2. A molten salt corrosion test apparatus under stress according to 2 or 3. 5. The strain adding device has a structure of a tensile compression tester which operates by hydraulic pressure.
2. A molten salt corrosion test apparatus under stress according to 2, 3, or 4. 6. The molten salt corrosion testing apparatus under stress according to claim 1, wherein the strain adding apparatus has a structure of a tensile compression testing machine using a combination of an electric motor and a gear. 7. The heat-resistant and high-corrosion resistant member is used for the ceiling surface / wall surface / bottom surface of the space for holding the test piece and the molten salt. Equipment for molten salt corrosion test under stress.