CN220872239U

CN220872239U - Lead bismuth environment fracture toughness testing arrangement

Info

Publication number: CN220872239U
Application number: CN202322650652.7U
Authority: CN
Inventors: 林一帆; 张勇; 邵强; 赵又杰
Original assignee: Jiangsu Bairuo Test Instrument Co ltd
Current assignee: Jiangsu Bairuo Test Instrument Co ltd
Priority date: 2023-09-27
Filing date: 2023-09-27
Publication date: 2024-04-30
Anticipated expiration: 2033-09-27

Abstract

The application relates to the technical field of test sample fracture toughness testing, and provides a lead bismuth environment fracture toughness testing device which comprises a frame, a test kettle arranged on the frame, a mounting frame arranged above the test kettle, a mounting seat arranged above the mounting frame for mounting a sample, a COD gauge arranged above the mounting seat, a loading unit arranged above the COD gauge for loading the sample, and a lifting assembly arranged on the frame for driving the mounting frame to lift; the liquid lead bismuth is filled in the test kettle, an inlet for the installation frame to enter the test kettle is formed in the upper portion of the test kettle, a notch which is arranged in a V shape is formed in the upper surface of the sample, and when the sample is placed in the liquid lead bismuth, the highest liquid level of the liquid lead bismuth is lower than the height that the gauge arm of the COD gauge is located at the highest end. The application has the beneficial effect of reducing the influence of the COD gauge on the test result of the three-point bending test sample.

Description

Lead bismuth environment fracture toughness testing arrangement

Technical Field

The application relates to the technical field of test sample fracture toughness, in particular to a lead bismuth environment fracture toughness testing device.

Background

With the improvement of metallurgical quality, high-strength and high-toughness alloy is increasingly applied to engineering as a structural material, and safety evaluation is often required. The plane strain fracture toughness is an important safety evaluation index and structural member design index, so that the plane strain fracture toughness of the high-strength high-toughness alloy obtained through testing is particularly important. The current test for the plane strain fracture toughness of high strength, high toughness alloys is through testing ductile fracture toughness. The three-point bending sample is often the first choice of the sample form in the field of metal material fracture mechanical property detection due to the advantages of simple form, rapid processing, strong representativeness and the like.

The notch on the existing three-point bending sample is usually positioned on the lower surface, and the COD gauge is arranged below the notch so as to apply force to the notch through the testing machine, at the moment, the COD gauge is used for measuring the opening displacement of the notch of the three-point bending sample positioned in the horizontal direction, and then the test value of the fracture toughness of the three-point bending sample is obtained through calculation through the testing machine.

Because some structural materials are used in high temperature and high corrosion environments, in order to build the environments, some of the prior art test methods have been to soak three-point bent samples in a lead-bismuth environment for fracture toughness testing.

When the three-point bending sample is subjected to fracture toughness test, the three-point bending sample needs to be soaked in a lead-bismuth environment, particularly a notch on the three-point bending sample needs to be soaked in the lead-bismuth environment, and as the COD gauge is arranged below the notch, the three-point bending sample can be soaked in the lead-bismuth environment together with the COD gauge, and as the lead-bismuth has the characteristics of high temperature and high corrosion, the COD gauge can be corroded to damage the normal use of the COD gauge, and further the test result of the COD gauge on the fracture toughness of the three-point bending sample is influenced, so that further improvement is needed.

Disclosure of utility model

In order to reduce the influence of a COD gauge on the test result of a three-point bending test sample, the application provides a lead bismuth environment fracture toughness testing device.

The application provides a lead bismuth environment fracture toughness testing device, which adopts the following technical scheme:

The utility model provides a plumbous bismuth environment fracture toughness testing arrangement, includes the frame, sets up the test kettle in the frame, sets up the mounting bracket in the test kettle top, sets up in the mount pad that is used for supplying the sample to install, sets up the COD rule in the mount pad top, sets up in the loading unit that carries out loading to the sample in the COD rule top and sets up in the frame in order to drive the lifting unit that the mounting bracket goes up and down; the liquid lead bismuth is filled in the test kettle, an inlet for the installation frame to enter the test kettle is formed in the upper portion of the test kettle, a notch which is arranged in a V shape is formed in the upper surface of the sample, and when the sample is placed in the liquid lead bismuth, the highest liquid level of the liquid lead bismuth is lower than the height that the gauge arm of the COD gauge is located at the highest end.

Through adopting above-mentioned technical scheme, be equipped with the mounting bracket, the mounting bracket provides the installation carrier for mount pad, COD rule and loading unit, place the sample on the mount pad after, and aim at the COD rule with the breach of sample and set up the back, then through lifting unit with drive the mounting bracket towards being close to the direction removal of sample cauldron, so that install in the sample of mount pad in the test cauldron, and soak in plumbous bismuth environment after, then the loading unit is in order to load the sample, measure the breach displacement on the sample through the breach of COD rule.

Through setting up COD rule in the top of sample, can reduce liquid plumbous bismuth and soak the sample in liquid plumbous bismuth together with COD rule, and because the highest liquid level of liquid plumbous bismuth is less than the rule arm of COD rule and is located the height of highest end to reduce plumbous bismuth and corrode the possibility that the normal use of COD rule in order to damage the COD rule, and then with the influence that reduces the COD rule at the test result to three-point bending sample fracture toughness.

Preferably, the test kettle is fixedly provided with an input pipe in a penetrating way, and the mounting frame is provided with a liquid level measuring part for measuring the liquid level of liquid lead bismuth in the test kettle.

Through adopting the technical scheme, after the lifting assembly drives the mounting frame to enter the test kettle, the liquid lead bismuth is input into the test kettle through the input pipe, namely, the liquid lead bismuth is input after the mounting frame is put into the test kettle, so that the possibility that the liquid lead bismuth splashes when the mounting frame is immersed into the liquid lead bismuth can be reduced, and the possibility that the liquid lead bismuth splashes outside the test kettle to accidentally injure operators or splash on the COD gauge can be reduced; because the mounting bracket is arranged in the test kettle, the liquid level of liquid lead bismuth in the test kettle is not easy to check, the liquid level of liquid lead bismuth is measured through the liquid level measuring piece at the moment so as to control the liquid level of liquid lead bismuth, so that the possibility that the liquid lead bismuth is soaked in the COD gauge is reduced, the possibility that the lead bismuth corrodes the COD gauge to damage the normal use of the COD gauge is reduced, and the influence of the COD gauge on the test result of the fracture toughness of the three-point bending test sample is reduced.

Preferably, the liquid level measuring part further comprises an alarm liquid level device, the height of the lowest end of the alarm liquid level device is lower than the height of the middle part of the gauge arm of the COD gauge, and the alarm liquid level device is electrically connected with the upper computer; the input pipe is provided with a control valve, the control valve is electrically connected with an electromagnetic valve, and the electromagnetic valve is electrically connected with an upper computer.

Through adopting above-mentioned technical scheme, when the liquid level of liquid plumbous bismuth is located the height that the warning liquid level meter is located the minimum, the warning liquid level meter is with corresponding liquid level information input to the host computer this moment after this to make the host computer pass through the control solenoid valve in order to close the control valve on the input tube, thereby with plumbous bismuth liquid level control, with the possibility that reduces plumbous bismuth and soak to COD rule, and then with the influence that reduces COD rule at the test result to three-point bending sample fracture toughness, still can make the sample soak in liquid plumbous bismuth.

Preferably, the alarm liquid level device is a ceramic liquid level device, and the ceramic liquid level device comprises a ceramic protection tube and a metal chip embedded at the lower end of the ceramic protection tube.

By adopting the technical scheme, the ceramic protection tube has the characteristics of high temperature resistance and corrosion resistance due to the property of ceramic, and can protect the lead wire connected between the liquid level device and the metal chip.

Preferably, a positioning assembly for positioning the sample is arranged between the mounting frame and the mounting seat, the positioning assembly comprises a butt roller and a tension spring, the butt roller is abutted to the sample, the tension spring is used for forcing the butt roller to be abutted to the sample, and the butt rollers are arranged at two positions and are arranged at intervals along the length direction of the mounting seat.

Through adopting above-mentioned technical scheme, because the sample is the crooked sample of three-point, the both ends of sample can be towards the direction fracture displacement of keeping away from in the breach, through the elasticity of extension spring self this moment to make the butt roller butt on the sample, because the peripheral wall of butt roller is the circumference setting, be the butt between the line face with the sample between, and when improving the positioning effect to the sample, with the frictional force between the reduction two, and then with the influence that reduces COD rule at the test result to the crooked sample fracture toughness of three-point.

Preferably, the tension springs are obliquely arranged, and the upper ends of the tension springs arranged on the two abutting rollers are arranged in the direction of approaching each other.

Through adopting above-mentioned technical scheme, be the slope setting with the extension spring, can make the sample in the engineering of loading so that the loading tube outwards remove to reduce the production of the frictional force between oblique roller and the sample, and then with the influence of reduction COD rule to the test result of three-point bending sample fracture toughness.

Preferably, the device further comprises a centering component arranged on the mounting frame for adjusting coaxiality between the sample and the loading unit.

Through adopting above-mentioned technical scheme, because when carrying out fracture toughness test to the sample, load the sample and supply the sample to install in prior art between the mount pad, in carrying out the course of working and all can produce certain error when assembling, make the axiality between sample and the loading unit surpass the deviation that the test allowed, and then make the COD rule to the data measurement of the fracture displacement of breach error to some extent, at this moment through being provided with the aligning subassembly, so that the axiality between the two is in the within range that the test allowed, in order to reduce because the axiality deviation is big so that the COD rule is at the influence to the test result of three-point bending sample fracture toughness.

Preferably, the aligning assembly comprises a reverse supporting shaft penetrating through the mounting seat to be abutted against the lower surface of the sample, an adjusting seat and a fixing seat coaxially sleeved on the reverse supporting shaft, and an adjusting bolt penetrating through the adjusting seat through threads; the notch and the reverse support shaft of sample are coaxial, the lower extreme fixed connection of fixing base in the mounting bracket, the second slot that supplies the upper end of fixing base to insert to establish is seted up to the lower terminal surface of adjusting seat, adjusting bolt is provided with a plurality of groups and around the axis interval distribution of adjusting seat, and a set of adjusting bolt is provided with two, and two adjusting bolt butt respectively in fixing base and reverse support shaft.

Through adopting above-mentioned technical scheme, because the lower extreme fixed connection of fixing base is in the mounting bracket, through the effort of adjusting the bolt application forward or reverse effort to change the interval between reverse back shaft and fixing base and the adjusting seat, thereby with the axiality between adjusting reverse back shaft and the loading unit, thereby reduce because axiality deviation is big so that COD rule is at the influence to the test result of three-point bending sample fracture toughness.

In summary, the utility model has the following beneficial effects:

1. Through setting up COD rule in the top of sample, can reduce liquid plumbous bismuth and soak the sample in liquid plumbous bismuth together with COD rule, and because the highest liquid level of liquid plumbous bismuth is less than the rule arm of COD rule and is located the height of highest end to reduce plumbous bismuth and corrode the possibility that the normal use of COD rule in order to damage the COD rule, and then with the influence that reduces the COD rule at the test result to three-point bending sample fracture toughness.

2. Through the form of input liquid plumbous bismuth after putting into the mounting bracket in advance, can reduce the liquid plumbous bismuth and appear the possibility that splashes when the mounting bracket soaks liquid plumbous bismuth to reduce liquid plumbous bismuth and splash outside the test kettle in order to accidentally injure operating personnel or splash on the COD rule.

3. The alignment assembly is arranged, so that the coaxiality between the two components is within the range allowed by the test, and the influence on the test result of the fracture toughness of the three-point bending test sample by the COD gauge due to large coaxiality deviation is reduced.

Drawings

FIG. 1 is a schematic overall structure of an embodiment of the present application;

FIG. 2 is a schematic view of a mounting frame according to an embodiment of the present application;

FIG. 3 is a schematic cross-sectional view of a centering assembly according to an embodiment of the present application;

FIG. 4 is a schematic view of the structure of the liquid level measuring member in the embodiment of the present application.

Reference numerals illustrate: 1. a frame; 11. a loading unit; 111. loading a unit mounting seat; 12. a lifting assembly; 2. a test kettle; 21. an access port; 22. an input tube; 23. a control valve; 3. a mounting frame; 31. a first mounting plate; 311. a lower pressure head; 32. a mounting roller; 33. a second mounting plate; 331. a third conditioning chamber; 4. a sample; 41. a notch; 5. a mounting base; 51. a placement groove; 6. COD gauge; 61. gauge arm; 7. a centering component; 71. a reverse support shaft; 711. a locking plate; 712. a locking bolt; 713. a backing ring; 72. an adjusting seat; 721. a first slot; 722. a second slot; 723. a first conditioning chamber; 73. a fixing seat; 731. a second conditioning chamber; 74. an adjusting bolt; 8. a positioning assembly; 81. a contact roller; 82. a tension spring; 9. a liquid level measuring member; 91. a first level gauge; 92. an intermediate liquid level device; 93. a working level gauge; 94. and (5) an alarm liquid level device.

Detailed Description

The present application will be described in further detail with reference to fig. 1-4.

The embodiment of the application discloses a lead bismuth environment fracture toughness testing device.

Examples:

The utility model provides a plumbous bismuth environment fracture toughness testing arrangement, refer to fig. 1, fig. 2, including frame 1, set up test kettle 2 in frame 1, set up in the mounting bracket 3 of test kettle 2 top, set up in mounting bracket 3 in order to be used for the mount pad 5 of sample 4 installation, set up in the COD rule 6 of mount pad 5 top, set up in the loading unit 11 that COD rule 6 top is loaded in order to carry out sample 4, set up in frame 1 with the lifting unit 12 that drive mounting bracket 3 goes up and down and set up in the centering subassembly 7 of axiality between mounting bracket 3 in order to adjust sample 4 and loading unit 11.

Referring to fig. 1 and 3, in this embodiment, the upper surface of the sample 4 has a V-shaped notch 41, and the loading unit 11 and the lifting assembly 12 are commonly used in the prior art, and will not be described in detail here.

Referring to fig. 1, in this embodiment, liquid lead bismuth is filled in a test kettle 2, an inlet 21 for a mounting frame 3 to enter the test kettle 2 is formed above the test kettle 2, an input pipe 22 is fixedly arranged on the bottom wall of the test kettle 2 in a penetrating manner, so that the liquid lead bismuth is input into the test kettle 2, in this embodiment, a control valve 23 is arranged on the input pipe 22, the control valve 23 is electrically connected to an electromagnetic valve, the electromagnetic valve is electrically connected to an upper computer, and as the electromagnetic valve and the upper computer are common technical means in the prior art, redundant description is omitted here. When the sample 4 is placed in liquid lead bismuth, the highest level of the liquid lead bismuth should be lower than the height of the gauge arm 61 of the COD gauge 6 at the highest end.

The input tube 22 is disposed at the bottom wall of the test kettle 2, so that the liquid lead bismuth can be introduced into the test kettle 2 by pressing after the whole mounting frame 3 is introduced into the test kettle 2, and the liquid lead bismuth can be recovered through the input tube 22 after the fracture toughness test of the sample 4 is completed.

Referring to fig. 2, in the present embodiment, the mounting frame 3 includes a first mounting plate 31 for mounting with the lifting assembly 12, four mounting rollers 32 fixedly connected to the lower surface of the mounting plate, and a second mounting plate 33 fixedly sleeved on the lower end of the mounting roller 32. Wherein, the lower pressure head 311 is arranged below the first mounting plate 31, and the loading mounting seat 5 for connecting the lower pressure head 311 and the loading unit 11 is fixedly connected to the lower surface of the first mounting plate 31, so as to load the sample 4.

Referring to fig. 2 and 3, the mounting base 5 is disposed below the lower ram 311, and the upper surface of the mounting base 5 has a placement groove 51 in which the sample 4 is slidably engaged, and the placement groove 51 extends to opposite end surfaces of the mounting base 5. Wherein, the COD gauge 6 sets up in last pressure head, and the gauge arm 61 butt in sample 4 of COD gauge 6, and gauge arm 61 is provided with two and just the butt is located the both sides of breach 41 in sample 4 respectively to the breach 41 fracture displacement on the sample 4 is measured, and in this embodiment, the COD gauge 6 electricity is connected in the host computer, in order to calculate the fracture displacement data transmission of the breach 41 of 6 degrees samples of COD gauge 4 to the host computer, thereby in order to obtain the measuring result of fracture toughness of sample 4.

Referring to fig. 2 and 3, further, in order to improve the positioning effect on the sample 4, a positioning assembly 8 for positioning the sample 4 is provided between the mounting frame 3 and the mounting seat 5, the positioning assembly 8 includes a contact roller 81 abutted above the sample 4 and a tension spring 82 forcing the contact roller 81 to abut against the sample 4, the contact roller 81 is provided with two sliding grooves for sliding the contact roller 81 and arranged at intervals along the length direction of the mounting seat 5, a sliding groove for sliding the contact roller 81 is provided on the lower end surface of the upper pressing head, two tension springs 82 are provided on one contact roller 81, the two tension springs 82 are fixedly connected to two ends of the contact roller 81 respectively, and the other end of the tension spring 82 is fixedly connected to the side wall of the upper pressing head. In this embodiment, the tension springs 82 are inclined, and the upper ends of the tension springs 82 disposed in the two abutment rollers 81 are disposed in directions approaching each other.

Referring to fig. 3 and 4, further, in order to detect and control the liquid level of the liquid lead bismuth in the test kettle 2, a liquid level measuring member 9 for measuring the liquid level of the liquid lead bismuth in the test kettle 2 is provided on the mounting frame 3, and is specifically mounted on the lower surface of the first mounting plate 31. Specifically, the liquid level measuring member 9 includes a first liquid level device 91, an intermediate liquid level device 92, an operating liquid level device 93 and an alarm liquid level device 94, wherein the height of the first liquid level device 91 at the lowest end is lower than the height of the second mounting plate 33 so as to check whether liquid lead bismuth exists in the test kettle 2. The intermediate level 92 is located at the lowest level above the upper surface of the mounting 5 to see that liquid bismuth is in contact with the sample 4. The working level gauge 93 is located at the lowest level below the gauge arm 61 of the COD gauge 6, so as to notice that the liquid level will completely dip through the sample 4 at this time, the alarm level gauge 94 is located at the lowest level below the gauge arm 61 of the COD gauge 6, and at this time, the corresponding liquid level information is transmitted to the upper computer, which controls the control valve 23 through the electromagnetic valve, so as to close the input pipe 22.

In this embodiment, the first liquid level device 91, the intermediate liquid level device 92, the working liquid level device 93 and the alarm liquid level device 94 are all electrically connected to the upper computer, and in this embodiment, the first liquid level device 91, the intermediate liquid level device 92, the working liquid level device 93 and the alarm liquid level device 94 are all ceramic liquid level devices, and the ceramic liquid level devices comprise a ceramic protection tube and a metal chip embedded in the lower end of the ceramic protection tube.

Referring to fig. 3, the aligning assembly 7 includes a reverse support shaft 71 penetrating through the lower surface of the mounting seat 5 to be abutted against the lower surface of the sample 4, an adjusting seat 72 and a fixing seat 73 coaxially sleeved on the reverse support shaft 71, and an adjusting bolt 74 threaded through the adjusting seat 72. In the present embodiment, the notch 41 of the sample 4 and the reverse support shaft 71 are coaxially arranged to change the coaxiality between the reverse support shaft 71 and the loading unit 11, thereby adjusting the coaxiality between the notch 41 on the sample 4 and the loading unit 11.

The upper end surface of the adjusting seat 72 is provided with a first slot 721 for inserting the reverse supporting shaft 71, the lower end surface of the adjusting seat 72 is provided with a second slot 722 for inserting the upper end of the fixing seat 73, the inner circumferential wall of the first slot 721 and the inner circumferential wall of the second slot 722 are provided with a first adjusting chamber 723, and the inner circumferential wall of the adjusting seat 72 and the inner circumferential wall of the fixing seat 73 are provided with a second adjusting chamber 731 communicated with the first adjusting chamber 723.

The lower end of the fixing seat 73 is fixedly connected to the upper surface of the second mounting plate 33, a third adjusting chamber 331 communicated with the second adjusting chamber 731 is formed in the second mounting plate 33 in a penetrating manner, the reverse supporting shaft 71 penetrates through the third adjusting chamber 331, a locking plate 711 is fixedly sleeved at the lower end of the reverse supporting shaft 71, a locking bolt 712 is threaded through the locking plate 711, a backing ring 713 is threaded to the locking bolt 712, and the backing ring 713 abuts against the lower surface of the second mounting plate 33.

In this embodiment, the adjusting bolts 74 are provided with a plurality of groups and are distributed at intervals around the axis of the adjusting seat 72, and specifically four groups of adjusting bolts 74 are provided, and two adjusting bolts 74 respectively abut against the fixing seat 73 and the reverse supporting shaft 71.

The implementation principle of the lead bismuth environment fracture toughness testing device provided by the embodiment of the application is as follows: when the fracture test is performed on the sample 4, it is necessary to adjust the coaxiality between the sample 4 and the loading unit 11, and apply a forward or reverse force to the adjusting bolt 74 to change the spacing between the bolt portion of the adjusting bolt 74 and the reverse support shaft 71 and the fixing seat 73, thereby changing the coaxiality between the reverse support shaft 71 and the loading unit 11, and locking by the locking bolt 712.

After coaxiality is adjusted, the sample 4 is placed on the mounting seat 5, so that the notch 41 on the sample 4 and the reverse support shaft 71 are coaxially arranged, the gauge arms 61 of the COD gauge 6 are abutted against the two sides of the notch 41, the abutting roller 81 is abutted against the upper surface of the sample 4, the lifting assembly 12 is used for driving the mounting frame 3 to enter the test kettle 2, then the liquid lead bismuth is input into the test kettle 2 through the input tube 22, when the input tube 22 is used for inputting, the liquid level of the liquid lead bismuth in the test kettle 2 is measured through the liquid level measuring piece 9, after the required height is reached, the loading unit 11 is started to load the sample 4, so that the fracture displacement of the notch 41 on the sample 4 is measured through the COD gauge 6, and the test of fracture toughness of the sample 4 is realized under the lead bismuth environment.

The above embodiments are not intended to limit the scope of the present application, so: all equivalent changes in structure, shape and principle of the application should be covered in the scope of protection of the application.

Claims

1. A lead bismuth environment fracture toughness testing arrangement, its characterized in that: the device comprises a frame (1), a test kettle (2) arranged on the frame (1), a mounting rack (3) arranged above the test kettle (2), a mounting seat (5) arranged on the mounting rack (3) for mounting a sample (4), a COD gauge (6) arranged above the mounting seat (5), a loading unit (11) arranged above the COD gauge (6) for loading the sample (4) and a lifting assembly (12) arranged on the frame (1) for driving the mounting rack (3) to lift; liquid lead bismuth is arranged in the test kettle (2), an inlet (21) for the installation frame (3) to enter the test kettle (2) is formed in the upper portion of the test kettle (2), a notch (41) which is arranged in a V shape is formed in the upper surface of the sample (4), and when the sample (4) is placed in the liquid lead bismuth, the highest liquid level of the liquid lead bismuth is lower than the height of the highest end of the gauge arm (61) of the COD gauge (6).

2. The lead bismuth environmental fracture toughness testing device according to claim 1, wherein: the test kettle (2) is fixedly provided with an input pipe (22) in a penetrating mode, and the mounting frame (3) is provided with a liquid level measuring piece (9) for measuring the liquid level of liquid lead bismuth in the test kettle (2).

3. The lead bismuth environmental fracture toughness testing device according to claim 2, wherein: the liquid level measuring piece (9) further comprises an alarm liquid level device (94), the height of the lowest end of the alarm liquid level device (94) is lower than the height of the middle part of the gauge arm (61) of the COD gauge (6), and the alarm liquid level device (94) is electrically connected to the upper computer; the input pipe (22) is provided with a control valve (23), the control valve (23) is electrically connected to an electromagnetic valve, and the electromagnetic valve is electrically connected to an upper computer.

4. A lead bismuth environmental fracture toughness testing apparatus according to claim 3, wherein: the alarm liquid level device (94) is a ceramic liquid level device, and the ceramic liquid level device comprises a ceramic protection tube and a metal chip embedded at the lower end of the ceramic protection tube.

5. The lead bismuth environmental fracture toughness testing device according to claim 1, wherein: the device is characterized in that a positioning assembly (8) for positioning the sample (4) is arranged between the mounting frame (3) and the mounting seat (5), the positioning assembly (8) comprises a butt roller (81) which is butt-jointed above the sample (4) and a tension spring (82) which forces the butt roller (81) to butt against the sample (4), and the butt rollers (81) are arranged at two positions and are arranged along the length direction of the mounting seat (5) at intervals.

6. The lead bismuth environment fracture toughness testing device according to claim 5, wherein: the tension springs (82) are obliquely arranged, and the upper ends of the tension springs (82) arranged on the two abutting rollers (81) are arranged in directions close to each other.

7. The lead bismuth environmental fracture toughness testing device according to claim 1, wherein: the device also comprises a aligning component (7) which is arranged on the mounting frame (3) and used for adjusting coaxiality between the sample (4) and the loading unit (11).

8. The lead bismuth environmental fracture toughness testing device according to claim 7, wherein: the aligning assembly (7) comprises a reverse supporting shaft (71) penetrating through the mounting seat (5) to be abutted against the lower surface of the sample (4), an adjusting seat (72) and a fixing seat (73) coaxially sleeved on the reverse supporting shaft (71), and an adjusting bolt (74) penetrating through the adjusting seat (72) in a threaded manner; notch (41) and reverse back shaft (71) of sample (4) are coaxial to be set up, the lower extreme fixed connection of fixing base (73) in mounting bracket (3), second slot (722) that supply the upper end of fixing base (73) to insert is seted up to the lower terminal surface of adjusting seat (72), adjusting bolt (74) are provided with a plurality of groups and around the axis interval distribution of adjusting seat (72), and a set of adjusting bolt (74) are provided with two, and two adjusting bolt (74) butt respectively in fixing base (73) and reverse back shaft (71).