CN112129643A - Device and method for obtaining creep deformation curve by using mechanical endurance testing machine - Google Patents
Device and method for obtaining creep deformation curve by using mechanical endurance testing machine Download PDFInfo
- Publication number
- CN112129643A CN112129643A CN202011104911.0A CN202011104911A CN112129643A CN 112129643 A CN112129643 A CN 112129643A CN 202011104911 A CN202011104911 A CN 202011104911A CN 112129643 A CN112129643 A CN 112129643A
- Authority
- CN
- China
- Prior art keywords
- lever
- leveling
- test
- sample
- obtaining
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/08—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces
- G01N3/10—Investigating strength properties of solid materials by application of mechanical stress by applying steady tensile or compressive forces generated by pneumatic or hydraulic pressure
- G01N3/12—Pressure testing
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N3/00—Investigating strength properties of solid materials by application of mechanical stress
- G01N3/02—Details
Abstract
The invention discloses a device and a method for obtaining a creep deformation curve by using a mechanical endurance testing machine, wherein the device comprises a lever system, an electric loading system, an automatic leveling system and a leveling switch action recording system, wherein the switch action recording system records the action time of a photoelectric switch when the mechanical endurance testing machine is leveled each time, the movable distance of the tail part of a lever between two times of leveling is utilized, the deformation of a sample between two times of leveling is calculated according to the lever ratio, and the relation between the endurance testing time and the plastic deformation of the sample can be obtained. Compared with the prior art, the device is simple and convenient, a switch action recorder can be installed on the existing mechanical endurance testing machine, a material creep deformation curve is obtained through simple calculation, and sample creep process information is obtained.
Description
Technical Field
The invention belongs to the field of creep endurance tests of metal materials, and particularly relates to a device and a method for obtaining a creep deformation curve by using a mechanical endurance testing machine.
Background
The phenomenon of deformation of a metallic material over time at high temperatures and under load is known as creep. For parts which bear the combined action of high temperature and load for a long time in the service process, such as boilers, steam turbines, aerospace engines, gas turbines and the like, the creep endurance performance of the material is a key index for designing and evaluating the residual life, and material performance data such as creep endurance strength, creep deformation curve, creep limit and the like can be obtained through a creep endurance test. The creep rupture tester comprises an electronic creep rupture tester and a mechanical creep rupture tester, wherein the electronic creep rupture tester cannot thoroughly solve the problem of electronic drift of load and is mainly used for short-time tests, and the mechanical creep rupture tester is mainly used for long-time tests due to stable load.
The creep rupture test format includes a creep test and a endurance test. The creep test conventionally comprises the steps of applying a constant load to a smooth uniform-section sample at a specified temperature, measuring the deformation of a gauge length section of the sample along with time by using an extensometer, recording time-deformation data, and simultaneously obtaining data such as creep endurance strength, a creep deformation curve, a steady-state creep rate and the like of the material at a certain temperature and under a certain load. In order to facilitate the clamping of the extensometer, lugs are required to be processed at two ends of a tested sample, a clamping space with a certain length is reserved, and the total length of a creep test sample is usually about 100mm or more; the gauge length diameter is typically at least 5mm to prevent the lug from weakening by a large difference in lug to gauge length diameter, and many parts cannot be made to process standard creep test specimens due to dimensional limitations. The endurance test sample is simpler than the creep test sample, a boss does not need to be processed, and an extensometer is not installed, so that the endurance test can only obtain the endurance strength under the test temperature and the load, and the data of the creep deformation process cannot be obtained. The mechanical endurance testing machine is simple in structure and stable in force value, and is often used for long-time high-temperature endurance tests for thousands of hours or even tens of thousands of hours.
Compared with the prior art, the creep test machine has the problems of complex structure, high requirement on the size of a sample material and high test cost. Whereas both the durable test sample and the test procedure are simpler, but lack process data. The mechanical endurance testing machine cannot judge the test proceeding degree in real time and estimate the approximate breaking time in the test proceeding process of thousands of hours or even thousands of hours.
Disclosure of Invention
The invention provides a device and a method for obtaining a creep deformation curve by using a mechanical endurance testing machine, aiming at the problems in the prior art, namely, an automatic leveling recording device is additionally arranged on the mechanical endurance testing machine, and the relation between the plastic deformation of a sample and time is obtained by calculation according to an automatic leveling stroke, so that the process data of the creep deformation of a material is obtained.
The invention is realized by the following technical scheme:
a device for obtaining a creep deformation curve by using a mechanical endurance test comprises a lever system, an electric loading system, an automatic leveling system and a leveling switch action recording system; wherein the content of the first and second substances,
the lever system comprises a knife bearing, a knife bearing edge lever fulcrum and levers which are arranged on two sides of the knife bearing edge lever fulcrum and used for keeping a set proportion, and a balance adjusting device is also arranged on the sample side of each lever;
one end of the test sample is used for being connected with the sample side of the lever, and the other end of the test sample is connected with the automatic leveling system through the lower pull rod; the other end of the lever, which is far away from the sample side, is provided with a leveling switch action recording system and is connected with a weight and a preload weight, and an electric loading system is arranged below the weight.
The invention is further improved in that one end of the sample is connected with the sample side of the lever through a first automatic centering device, and the other end of the sample is connected with the automatic leveling system through a second automatic centering device.
The invention has the further improvement that the electric loading system comprises a loading tray, a loading motor and a buffer oil cylinder, wherein one end of the buffer oil cylinder is connected with the loading motor, the other end of the buffer oil cylinder is connected with the loading tray, so that the test can be automatically loaded after the test reaches the heat preservation time, and after the test sample is fractured, the weight can stably fall on the tray through the buffer oil cylinder, thereby avoiding the impact and the damage of the mechanism.
The invention is further improved in that the automatic leveling system comprises a leveling motor, the output end of the leveling motor is connected with the input end of a speed reducer through a V-belt transmission, and the output end of the speed reducer is connected with a lower pull rod through a ball screw pair and a ball screw.
The invention is further improved in that the leveling switch action recording system comprises a position pointer, a lower photoelectric switch, an upper photoelectric switch and a switch action recorder connected with the lower photoelectric switch, wherein the position pointer is arranged on the loading suspension rod between the lever and the preload weight.
A method for using a device for obtaining a creep deformation curve by using a mechanical endurance test comprises the steps that in the test process, a sample extends under the action of high temperature and stress, the tail part of a lever inclines downwards, when the tail part of the lever descends to a lower photoelectric switch, the lower photoelectric switch is triggered to act, a leveling motor rotates to drive the sample to move downwards slowly, the tail part of the lever ascends gradually, when the tail part of the lever reaches an upper photoelectric switch, the upper photoelectric switch is triggered to act, the leveling motor stops, and a switch action recorder records the time of each time of the action of the lower photoelectric switch; during testing, the lever swings within an allowable range under the control of the upper and lower photoelectric switches; and obtaining the moving range of the tail part of the lever between two leveling according to the position scale change range of the position pointer arranged on the loading suspension rod, calculating the deformation of the sample between two leveling according to the lever ratio, and obtaining the relation between the duration test time and the plastic deformation of the sample by combining the action time of the lower photoelectric switch.
Compared with the prior art, the invention has at least the following beneficial technical effects:
the device for obtaining the creep deformation curve by using the mechanical endurance test can be used for mounting a switch action recorder on the conventional mechanical endurance test machine, is simple to mount and low in price, and can obtain the time corresponding to each leveling so as to obtain the process information of the creep deformation of the material.
The use method of the device for obtaining the creep deformation curve by using the mechanical endurance test can obtain the creep deformation curve of the material and obtain the information of the creep deformation process only by simple one-step division calculation.
Drawings
FIG. 1 is a creep deformation curve of T91 steel obtained by the present invention at 600 deg.C/210 MPa.
FIG. 2 is a schematic structural diagram of an apparatus for obtaining a creep deformation curve by a mechanical endurance test according to the present invention.
Description of reference numerals:
1. a lever; 2. a knife bearing blade lever fulcrum; 3. a balance adjusting device; 4. a first self-aligning device; 5. a sample; 6. A second self-aligning device; 7. a ball screw; 8. a ball screw pair; 9. a speed reducer; 10. v-belt transmission; 11. A leveling motor; 12. a buffer oil cylinder; 13. a loading motor; 14. loading the tray; 15. a weight; 16. preloading weights; 17. A position pointer; 18. a lower photoelectric switch; 19. a photoelectric switch; 20. a switch action recorder; 21. and a pull rod is pulled down.
Detailed Description
The invention is further described below with reference to the following figures and examples.
As shown in fig. 2, the device for obtaining a creep deformation curve by using a mechanical endurance test provided by the invention comprises a lever system, an electric loading system, an automatic leveling system and a leveling switch action recording system.
The lever system comprises a knife bearing, a knife bearing edge lever fulcrum 2 and levers 1 which are arranged on two sides of the knife bearing edge lever fulcrum and keep a set proportion, and a balance adjusting device 3 is also arranged on the sample side of the lever 1; one end of the sample 5 is connected with the sample side of the lever 1 through a first automatic aligning device 4, and the other end of the sample is connected with an automatic leveling system through a second automatic aligning device 6; the other end of the lever 1, which is far away from the sample side, is provided with a leveling switch action recording system, and is connected with a weight 15 and a preload weight 16, and an electric loading system is arranged below the weight 15.
The electric loading system comprises a loading tray 14, a loading motor 13 and a buffer oil cylinder 12, wherein one end of the buffer oil cylinder 12 is connected with the loading motor 13, the other end of the buffer oil cylinder 12 is connected with the loading tray 14, so that the test can be automatically loaded after reaching the heat preservation time, after the test sample 5 is fractured, the test sample can be relieved through the buffer oil cylinder 12, and the weight 15 can stably fall on the tray 14, so that the impact and the damage of the mechanism can be avoided.
The automatic leveling system comprises a leveling motor 11, the output end of the leveling motor 11 is connected with the input end of a speed reducer 9 through a V-belt transmission 10, and the output end of the speed reducer 9 is connected with a lower pull rod 21 through a ball screw pair 8 and a ball screw 7. The triangular belt transmission 10, the speed reducer 9 and the ball screw pair 8 rotate in sequence, so that the ball screw 7 drives the lower pull rod 21, the sample 5 and the like to slowly move downwards, and the leveling purpose is achieved.
The leveling switch action recording system comprises a position pointer 17, a lower photoelectric switch 18, an upper photoelectric switch 19 and a switch action recorder 20 connected with the lower photoelectric switch 18, wherein the position pointer 17 is arranged on a loading suspension rod between the lever 1 and the preload weight 16.
The invention provides a method for using a device for obtaining a creep deformation curve by using a mechanical endurance test, wherein in the test process, a sample 5 extends under the action of high temperature and stress, the tail part of a lever 1 inclines downwards, when the tail part of the lever descends to a lower photoelectric switch 18, the lower photoelectric switch 18 is triggered to act, a leveling motor 11 rotates to drive the sample 5 to slowly move downwards, the tail part of the lever gradually ascends, when the tail part of the lever reaches an upper photoelectric switch 19, an upper photoelectric switch 19 is triggered to act, the leveling motor 11 stops, and a switch action recorder 20 records the time of the action of the lower photoelectric switch 18 each time; during testing, the lever 5 swings within an allowable range under the control of the upper and lower photoelectric switches; and obtaining the moving range of the tail part of the lever between two leveling according to the position scale change range of a position pointer 17 arranged on the loading suspension rod, calculating the deformation of the sample between two leveling according to the lever ratio, and obtaining the relation between the duration test time and the plastic deformation of the sample by combining the action time of a lower photoelectric switch 18.
Example (b):
as shown in fig. 1, a CTM504 type endurance testing machine, a endurance test specimen T91, a test temperature of 600 ℃, a stress of 210MPa, a leveling time of each time after the start of the test, a deformation distance of a pointer of a leveling weight of 4mm, a lever ratio of 50: 1, calculating to obtain a first leveling sample with increased plastic deformation of 4/50-0.08 mm, taking the time interval between each leveling and the beginning of the test as an abscissa and the leveling times multiplied by 0.08 as an ordinate, obtaining a creep deformation curve shown in figure 1, wherein the creep deformation curve is a standard three-stage creep deformation curve, and the elongation of the sample obtained by calculation is consistent with the comparison result of the elongation after fracture of the fracture sample, thereby proving that the method is feasible.
Claims (6)
1. A device for obtaining a creep deformation curve by using a mechanical endurance test is characterized by comprising a lever system, an electric loading system, an automatic leveling system and a leveling switch action recording system; wherein the content of the first and second substances,
the lever system comprises a knife bearing, a knife bearing edge lever fulcrum (2) and levers (1) which are arranged on two sides of the knife bearing edge lever fulcrum and keep a set proportion, and a balance adjusting device (3) is also arranged on the sample side of each lever (1);
one end of the test sample (5) is used for being connected with the sample side of the lever (1), and the other end of the test sample is connected with an automatic leveling system through a lower pull rod (21); the other end of the lever (1) far away from the sample side is provided with a leveling switch action recording system, and is connected with a weight (15) and a preload weight (16), and an electric loading system is arranged below the weight (15).
2. The device for obtaining creep deformation curve by mechanical endurance test according to claim 1, wherein one end of the test specimen (5) is connected to the sample side of the lever (1) through a first self-aligning device (4), and the other end is connected to the automatic leveling system through a second self-aligning device (6).
3. The device for obtaining the creep deformation curve by using the mechanical endurance test is characterized in that the electric loading system comprises a loading tray (14), a loading motor (13) and a buffer oil cylinder (12) with one end connected with the loading motor (13), the other end of the buffer oil cylinder (12) is connected with the loading tray (14), so that the test can be automatically loaded after reaching the heat preservation time, after the test sample (5) is broken, the test sample can be relieved through the buffer oil cylinder (12), and the weight (15) can stably fall on the tray (14), so that the mechanism can be prevented from being impacted and damaged.
4. The device for obtaining the creep deformation curve by using the mechanical endurance test is characterized in that the automatic leveling system comprises a leveling motor (11), the output end of the leveling motor (11) is connected with the input end of a speed reducer (9) through a V-belt transmission (10), and the output end of the speed reducer (9) is connected with a lower pull rod (21) through a ball screw pair (8) and a ball screw (7).
5. The device for obtaining creep deformation curve by mechanical endurance test according to claim 4, wherein the leveling switch action recording system comprises a position pointer (17), a lower photoelectric switch (18), an upper photoelectric switch (19) and a switch action recorder (20) connected with the lower photoelectric switch (18), the position pointer (17) is arranged on the loading suspension rod between the lever (1) and the preload weight (16).
6. The use method of the device for obtaining the creep deformation curve by using the mechanical endurance test is characterized in that in the test process, the test sample (5) extends under the action of high temperature and stress, the tail part of the lever (1) inclines downwards, when the tail part of the lever descends to the lower photoelectric switch (18), the lower photoelectric switch (18) is triggered to act, the leveling motor (11) rotates to drive the test sample (5) to move downwards slowly, the tail part of the lever gradually ascends, when the tail part of the lever reaches the upper photoelectric switch (19), the upper photoelectric switch (19) is triggered to act, the leveling motor (11) stops, and the switch action recorder (20) records the time of each time when the lower photoelectric switch (18) acts; during test, under the control of the upper and lower photoelectric switches, the lever (5) swings within an allowable range; and obtaining the moving range of the tail part of the lever between two leveling according to the position scale change range of a position pointer (17) arranged on the loading suspension rod, calculating the deformation of the sample between two leveling according to the lever ratio, and obtaining the relation between the duration test time and the plastic deformation of the sample by combining the action time of a lower photoelectric switch (18).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011104911.0A CN112129643A (en) | 2020-10-15 | 2020-10-15 | Device and method for obtaining creep deformation curve by using mechanical endurance testing machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011104911.0A CN112129643A (en) | 2020-10-15 | 2020-10-15 | Device and method for obtaining creep deformation curve by using mechanical endurance testing machine |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112129643A true CN112129643A (en) | 2020-12-25 |
Family
ID=73853020
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011104911.0A Pending CN112129643A (en) | 2020-10-15 | 2020-10-15 | Device and method for obtaining creep deformation curve by using mechanical endurance testing machine |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112129643A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113008679A (en) * | 2021-03-03 | 2021-06-22 | 上海发电设备成套设计研究院有限责任公司 | Creep rate measuring method based on endurance test |
-
2020
- 2020-10-15 CN CN202011104911.0A patent/CN112129643A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113008679A (en) * | 2021-03-03 | 2021-06-22 | 上海发电设备成套设计研究院有限责任公司 | Creep rate measuring method based on endurance test |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Miller | Testing and Analysis | |
| CN109917251B (en) | Method for predicting aging life of XLPE cable insulation material | |
| CN101975701B (en) | Concrete fracture test system and test method thereof | |
| Mindel et al. | Creep and recovery of polycarbonate | |
| CN112129643A (en) | Device and method for obtaining creep deformation curve by using mechanical endurance testing machine | |
| US11598705B2 (en) | Apparatus and method for measuring creep crack growth property using small specimen with micro groove | |
| CN111458243B (en) | Experimental method for measuring mechanical properties of metal by using indentation instrument | |
| SAXENA | A model for predicting the effect of frequency on fatigue crack growth behavior at elevated temperature | |
| Haapakangas et al. | A method for evaluating coke hot strength | |
| CN213397991U (en) | Device for obtaining creep deformation curve by using mechanical endurance testing machine | |
| CN107505213A (en) | A kind of new small punch test device and its test method | |
| CN218212343U (en) | Rock lever type single-shaft creep test device | |
| CN115266433A (en) | Fatigue crack propagation threshold value testing method | |
| CN215115502U (en) | A test device for rock developments is direct to be cuted | |
| US3075378A (en) | Methods and apparatus for the determination of thermal stresses | |
| JP3372437B2 (en) | Creep life evaluation method for high temperature equipment materials | |
| CN2606894Y (en) | Limiting expansion and contraction device for concrete | |
| CN208780563U (en) | Loading test device for explosive creep test when long | |
| RU2204817C1 (en) | Procedure establishing technical state of materials of structural members | |
| CN112945752A (en) | Device for testing high-temperature creep property of metal and testing method using device | |
| Yamashita et al. | The stress-relaxation behavior of type 304 stainless steel | |
| CN213337031U (en) | Strain loader | |
| Chvostová et al. | Creep test with use of miniaturized specimens | |
| CN113008679B (en) | Creep rate measuring method based on endurance test | |
| CN112179771B (en) | Solid propellant dependent variable loader and use method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |