CN111579321A - Quantitative linear scratching device for tubular sample and method of using the same - Google Patents

Abstract

The invention relates to the field of heat transfer pipe surface defect corrosion assessment, in particular to a quantitative linear scratching device for a tubular sample and a using method thereof. The device comprises a main frame, a clamping fixing pipe sleeve, a sample stand platform, a guide groove and a scratch frame, wherein a tubular sample is arranged on an arc-shaped groove on the upper surface of the sample stand platform, two gantry pressure pipe fixing devices which are arranged on the sample stand platform in a crossing mode and are arranged at the top of the tubular sample are arranged on the sample stand platform in a relatively parallel mode, each gantry pressure pipe fixing device corresponds to the tubular sample through a V-shaped groove in the bottom of a V-shaped pressing block on the gantry pressure pipe fixing device, the arc-shaped groove in the upper surface of the sample stand platform corresponds to a V-shaped groove in the bottom of the V-shaped pressing block, the tubular sample is clamped with the sample stand. The device can realize the linear fish tail of quantitative surface of tubulose sample, solves the tubulose quantitative fish tail sample preparation problem that is used for corrosion test in high temperature high pressure aquatic.

Description

Quantitative linear scratching device for tubular sample and method of using the same

technical field

The invention relates to the field of surface defect corrosion assessment of heat transfer tubes, in particular to a quantitative linear scratching device for a tubular sample and a method for using the same.

Background technique

In engineering, scratch surface defects often appear in the use of metal structural materials, and the degree of plastic deformation around the scratch affects the service performance of the metal, such as wear resistance and stress corrosion resistance. For example, in the process of production, transportation and installation of heat transfer tubes, it is difficult to avoid scratches and surface defects on the surface of heat transfer tubes. There have been many cases in the world of steam generator heat transfer tube failures caused by scratched surface defects. The scratched area has large residual stress, severe plastic deformation, gradient grain size, high surface activity, and is easily eroded in corrosive media to cause stress corrosion. Therefore, it is necessary to scientifically evaluate the effects of scratched surface defects of various scales on the surface microstructure and corrosion performance of heat transfer tubes, which can provide scientific reference for the design and life extension of key components of nuclear power plants (such as steam generator heat transfer tubes). It is of great significance to the safe operation of my country's nuclear power plants. Under the condition of precise control of other experimental parameters, quantitative preparation of surface linear scratch samples with different depths, different scratch angles, and different scratch rates is the basis for related research. The invention is mainly a device for preparing quantitative linear scratches on the surface of heat transfer tubes.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a quantitative linear scratching device for tubular samples and a method of using the same, which can prepare quantitative linear scratching simulation samples on the surface of heat transfer tubes, and solve the problem of tubular quantitative linear scratching used for corrosion testing in high temperature and high pressure water. Specimen Preparation Issues

The technical scheme of the present invention is as follows:

A quantitative linear scratching device for tubular samples. The main frame is provided with a clamping and fixing tube sleeve, a sample rack, a guide groove and a scratching frame. The main frame includes a main frame side plate and a main frame platform. It is vertically arranged on one side of the main frame platform, the middle of one side of the main frame side plate is provided with a clamping and fixed tube sleeve, the sample rack is arranged on the main frame platform on one side of the main frame side plate, and the tubular sample is arranged on the test On the arc-shaped groove on the upper surface of the sample rack table, two gantry pressure tube fixing devices spanning the top of the tubular sample are arranged in parallel on the sample rack table. Each gantry pressure tube fixing device passes through the bottom of the V-shaped compression block. The V-shaped groove corresponding to the tubular sample, the arc-shaped groove on the upper surface of the sample stand corresponds to the V-shaped groove at the bottom of the V-shaped pressing block, so that the tubular sample passes through the gantry pressing tube fixing device up and down and the test sample. The sample stand is clamped, and one end of the tubular sample is inserted into the clamping fixed sleeve;

The scratch frame is a structure with a cantilever on the upper end of a single column. The end of the cantilever is provided with a locking mechanism, a guide block and a scratch mechanism from top to bottom. The guide block is equipped with a locking mechanism, and the upper end of the scratch mechanism There is a ruler, the ruler passes through the guide block and the slat-shaped locking mechanism in turn, and is in sliding fit with the guide block and the slat-shaped locking mechanism, and the locking bolt is installed in the side opening of the locking mechanism. The lower end of the scratching mechanism is installed with a conical head corresponding to the surface of the tubular sample by the locking bolt and the ruler for locking and positioning; the lower end of the single column is installed in the guide groove on the other side of the main frame platform, The guide groove and the tubular sample are in the same horizontal direction, and one end of the transmission rod extends into the guide groove to connect with the lower end of the single column.

In the tubular sample quantitative linear scratching device, the other end of the transmission rod is connected to the straight-forward motor, the straight-forward motor is connected to the power supply through the frequency converter, the scratching frame is driven by the straight-forward motor, and the scratching frame drives the scratching mechanism along the line Sexual movement.

In the quantitative linear scratching device for the tubular sample, the frequency of the frequency converter is adjustable from 0 to 100 Hz, so as to realize the different linear speed control of the scratching mechanism during the preparation process.

In the tubular sample quantitative linear scratching device, in order to protect the original surface state of the tubular sample, a buffer cotton is provided at the contact place where the sample rack and the gantry pressure tube fixing device clamp the tubular sample.

The tube-shaped sample quantitative linear scratching device, the gantry pressure tube fixing device is composed of a rotary disk, a screw, a gantry frame, a chute, and a V-shaped pressing block, and the specific structure is as follows:

There are threaded holes in the middle of the top of the gantry, and the vertically arranged screw rods pass through the screw holes. The two sides of the gantry are in sliding fit with the vertical chutes on the opposite sides of the gantry, and the bottom of the V-shaped pressing block is provided with a V-shaped groove corresponding to the tubular sample.

For the quantitative linear scratching device for tubular samples, when in use, two gantry pressure tube fixing devices are fixed on a sample rack with arc-shaped grooves, and the gantry pressure tube fixing device and the sample rack are integrally connected. In this way, the fixation of the tubular specimen is achieved.

The tubular sample quantitative linear scratching device, the scratching mechanism is composed of a contact sensor, a cylindrical rod, a conical head sleeve, an upper fastening bolt hole, a lower fastening bolt hole, and a conical head. The specific structure is as follows:

The top and bottom cylindrical rods that are in close contact are arranged, the conical head is passed through the conical head sleeve, the contact sensor is installed on the cylindrical rod and the upper side of the conical head sleeve is exposed; the upper side of the conical head sleeve is provided with an upper fastening Bolt holes, the upper fastening bolts are installed in the upper fastening bolt holes, and the cylindrical rod is firmly fixed to the conical head sleeve through the upper fastening bolts; the lower fastening bolt holes are provided on the lower side of the conical head sleeve, and the lower fastening bolts are provided. The fixing bolt is installed in the lower tightening bolt hole, and the conical head is a structure in which the cylindrical section and the conical section are integrated up and down. The lower end of the tapered section of the head corresponds to the tubular specimen to be scratched.

In the tubular sample quantitative linear scratching device, the lower end of the ruler is connected to the upper end of the cylindrical rod, and the scratch depth of the conical head is adjusted up and down through the ruler to realize the quantitative preset of the scratch depth; When the shape head touches the tubular sample, the contact sensor gives a signal feedback, which is used as the adjustment zero point of the ruler.

The tubular sample quantitative linear scratching device, the conical head is made of YG series hard alloy, and the cylindrical rod is made of TWIP steel.

The use method of the described tubular sample quantitative linear scratching device, the specific steps are as follows:

(1) Select the conical head matching the required scratch angle, and install the conical head into the sleeve of the conical head. During the installation process, the conical head and the cylindrical rod are closely matched, and the top is completely tightened. Fastening bolt holes and upper fastening bolt holes for fastening;

(2) Fix the tubular sample, insert the tubular sample into the clamping and fixing tube sleeve, and place it on the sample stand; rotate the turntable, continuously press down the V-shaped pressing block, and compress the tubular sample until the tubular sample is The sample cannot rotate freely and move back and forth;

(3) Connect the power supply with 220V power supply, adjust the frequency of the inverter to make it reach the scratch rate required for the preparation, press the "forward" button of the inverter, and align the bottom of the conical head with the tubular sample;

(4) Move down through the ruler until the conical head at the lower end of the scratching mechanism touches the highest point of the surface of the tubular sample, and the contact sensor emits a beep. At this time, screw the locking bolt to fix the entire scratching mechanism. At this height, set the moment scale to zero;

(5) Press the "reverse" button of the inverter to move the conical head out of the top of the tubular sample; lower the ruler to the required scratch depth, and then tighten the fastening bolts;

(6) To prepare scratches, press the "forward" button of the inverter, the straight-forward motor pushes the transmission rod to move forward, and the tubular sample is linearly scratched through the tapered head to complete the scratch preparation;

(7) Press the "Stop" button of the frequency converter, loosen the locking bolt, raise the ruler, loosen the turntable, and take out the tubular sample with linear scratches on the desired surface.

The advantages and beneficial effects of the present invention are:

1. The device of the present invention can quantitatively prepare surface linear scratch samples with different scratch depths, different scratch angles and different scratch rates, which can not only ensure the accuracy of the scratch geometry and precisely control the scratch rate at the same time, It also has the characteristics of easy operation, good economy and high practicability.

2. In the present invention, V-shaped clamping is set on the upper and lower sides of the tubular sample at the same time, the upper clamping is a gantry pressure tube fixing device, and the lower clamping is a sample rack with a V-shaped opening; the clamping end is provided with a buffer cotton, The utility model can realize the tightening and reliable clamping under the condition of protecting the original surface state of the pipe material, and the clamping and fixing pipe sleeve at the matching end has good tightening effect, simple installation and convenient operation.

3. The present invention is not only applicable to the linear scratch of standard tubular specimens, but also to the preparation of C-ring test specimens with surface linear scratch defects by improving the clamping mechanism.

4. The scratch mechanism in the present invention adopts a rigid design, which can effectively avoid the problem of plastic deformation caused by insufficient rigidity in the scratch process, thereby effectively reducing the scratch depth error, and at the same time, a contact sensor is used to increase the accuracy of zero point correction. .

5. In the present invention, the scratching mechanism and the guide block are locked and fastened with locking bolts, upper fastening bolts and lower fastening bolts, which have high reliability and firm locking.

Description of drawings

Figure 1 is a schematic structural diagram of a quantitative linear scratching device for tubular samples. In the figure, 1 power supply; 2 inverter; 3 straight motor; 4 transmission rod; 5 guide groove; 6 scratch frame; 7 gantry pressure tube fixing device; 8 scratch mechanism; 11 locking bolt; 12 guide block; 13 main frame; 131 main frame side plate; 132 main frame platform; 14 tubular sample;

FIG. 2 is a schematic structural diagram of the gantry pressing tube fixing device 7 . In the figure, 71 turntable; 72 screw; 73 gantry; 74 chute; 75V-type compression block.

FIG. 3 is a schematic structural diagram of the scratching mechanism 8 . In the figure, 81 contact sensor; 82 cylindrical rod; 83 conical head sleeve; 84 upper fastening bolt hole; 85 lower fastening bolt hole; 86 conical head.

4-5 are schematic diagrams of the assembly relationship among the scratching mechanism 8 , the locking mechanism 10 , and the guide block 12 . Wherein, FIG. 4 is a perspective view, and FIG. 5 is an enlarged view of part I in FIG. 4 . In the figure, 8 scratch mechanism; 9 ruler; 10 locking mechanism; 101 chute fastening bolt hole; 102 longitudinal chute; 11 locking bolt; 12 guide block; 121 longitudinal guide rail.

Detailed ways

In the specific implementation process, the tubular sample quantitative linear scratching device of the present invention is mainly composed of a power supply, a frequency converter, a linear motor, a transmission rod, a guide groove, a scratching frame, a gantry pressure tube fixing device, a ruler, and a locking mechanism. , locking bolt, guide block, scratching mechanism, sample rack, clamping and fixing tube sleeve, main frame, etc. The main frame of the device is provided with a sample rack with an arc-shaped groove, and the upper part of the sample rack is provided with two A gantry pressure tube fixing device, the main frame side plate of the device is provided with a clamping and fixing tube sleeve; a scratching mechanism is arranged above the sample rack, and the scratching mechanism consists of a scratched cone head sleeve, a cone head, a contact sensor, It is composed of a ruler, a locking mechanism, a cylindrical rod, and a guide block; the scratching mechanism is connected with the linear motor through the scratching frame, the guide groove, and the transmission rod, so as to obtain the power to drive the scratching mechanism to move linearly in the horizontal direction; The motor is connected with the frequency converter and the power supply, and the speed and the feeding direction of the scratching mechanism are adjusted. When in use, through the contact sensor of the cylindrical rod, the tapered head of the scratching mechanism with a preselected angle contacts the surface of the tubular sample, and then the ruler is zeroed, and then the tapered head of the scratching mechanism is fed up and down through the ruler. Adjust the amount, and then lock the scratch mechanism. Control the linear motor frequency converter to realize the relative movement of the scratch mechanism and the fixed tubular sample, and complete the scratch preparation of the preset angle and quantitative depth.

As shown in Figures 1-5, the tubular sample quantitative linear scratching device of the present invention mainly includes: a power supply 1, a frequency converter 2, a linear motor 3, a transmission rod 4, a guide groove 5, a scratching frame 6, a gantry pressure Tube fixing device 7, scratching mechanism 8, ruler 9, locking mechanism 10, locking bolt 11, guide block 12, main frame 13, tubular sample 14, sample rack 15, clamping and fixing tube sleeve 16, The specific structure is as follows:

The main frame 13 is provided with a clamping and fixing tube sleeve 16, a sample stand 15, a guide groove 5, and a scratch frame 6. The main frame 13 includes a main frame side plate 131 and a main frame platform 132. The main frame side plate 131 is along the vertical direction. It is arranged on one side of the main frame platform 132, the middle of one side of the main frame side plate 131 is provided with a clamping and fixing tube sleeve 16, and the sample rack 15 is arranged on the main frame platform 132 on one side of the main frame side plate 131. The sample 14 is arranged on the arc-shaped groove on the upper surface of the sample holder 15, and two gantry pressure tube fixing devices 7 are arranged on the sample holder 15 in parallel and across the top of the tubular sample 14. Each gantry pressure tube fixing device 7. The V-shaped groove at the bottom of the V-shaped pressing block 75 corresponds to the tubular sample 14, and the arc-shaped groove on the upper surface of the sample holder 15 corresponds to the V-shaped groove at the bottom of the V-shaped pressing block 75. , so that the tubular sample 14 is clamped up and down through the gantry pressure tube fixing device 7 and the sample rack 15 , and one end of the tubular sample 14 is inserted into the clamping and fixing sleeve 16 .

As shown in Figure 1, Figure 4, Figure 5, the scratch frame 6 is a structure with a cantilever on the upper end of a single column, and the end of the cantilever is provided with a locking mechanism 10, a guide block 12, and a scratch mechanism from top to bottom. 8. The upper end surface of the guide block 12 is provided with a longitudinal guide rail 121 parallel to the direction of the side plate 131 of the main frame, and the lower end surface of the locking mechanism 10 is provided with a longitudinal slide groove 102 corresponding to the longitudinal guide rail 121. The longitudinal guide rail 121 and the longitudinal slide groove 102 Slip fit. The longitudinal chute 102 is provided with chute fastening bolt holes 101 on the side, and the chute fastening bolts are inserted into the chute fastening bolt holes 101 and correspond to the longitudinal guide rails 121. The longitudinal guide rail 121 is firmly fixed. The longitudinal sliding groove 102 of the locking mechanism 10 is installed into the longitudinal guide rail 121 of the guide block 12 to realize longitudinal fine adjustment, ensuring that the scratching mechanism 8 is located just above the tubular sample 14 . The upper end of the scratching mechanism 8 is provided with a ruler 9, and the ruler 9 passes through the guide block 12 and the slat-shaped locking mechanism 10 in turn, and is in sliding fit with the guide block 12 and the slat-shaped locking mechanism 10, and the lock is locked. The locking bolt 11 is installed in the side opening of the tightening mechanism 10, and the locking bolt 11 is locked and positioned with the ruler 9. The lower end of the scratching mechanism 8 is installed with a conical head 86 corresponding to the surface of the tubular sample 14. The locking mechanism 10 and the locking bolt 11 perform a locking operation on the scratching mechanism 8 .

The lower end of the single column is installed in the guide groove 5 on the other side of the main frame platform 132, the guide groove 5 and the tubular sample 14 are in the same horizontal direction, and one end of the transmission rod 4 extends into the guide groove 5 and the single column. The lower end is connected, the other end of the transmission rod 4 is connected with the straight motor 3, the straight motor 3 is connected with the power supply 1 through the frequency converter 2, and the scratch frame 6 is driven by the straight motor 3, and the scratch frame 6 drives the scratch mechanism 8 along the line Sexual movement. The frequency of the frequency converter 2 is adjustable from 0 to 100 Hz, so as to realize the different linear speed control of the scratching mechanism in the preparation process. In order to protect the original surface state of the tubular sample 14, buffer cotton is provided at the contact point of the sample rack 15 and the gantry pressure tube fixing device 7 to clamp the tubular sample 14, so as to avoid the surface damage of the tubular sample 14 and increase the friction force to enhance the clamping and fixing effect.

As shown in FIG. 2 , the gantry pressing tube fixing device 7 is composed of a rotary disk 71, a screw 72, a gantry frame 73, a chute 74, and a V-shaped pressing block 75. The specific structure is as follows:

The top of the gantry frame 73 is provided with a threaded hole in the middle, and the vertical screw 72 is penetrated through the screw hole. , the two sides of the V-shaped pressing block 75 are in sliding fit with the vertical chute 74 on the opposite sides of the gantry 73, and the bottom of the V-shaped pressing block 75 is provided with a V-shaped groove corresponding to the tubular sample 14 . When in use, the two gantry pressure tube fixing devices 7 are fixed on the sample rack 15 with the arc groove, and the rotary plate 71 of the gantry pressure tube fixing device 7 is twisted to drive the screw rod 72 to move downward and be embedded in the chute 74. The V-shaped pressing block 75 compresses the tubular sample 14; wherein, the gantry pressing tube fixing device 7 and the sample rack 15 are integrally connected, so as to realize the fixing of the tubular sample 14.

As shown in FIG. 3 , the scratching mechanism 8 is composed of a contact sensor 81, a cylindrical rod 82, a conical head sleeve 83, an upper fastening bolt hole 84, a lower fastening bolt hole 85, and a conical head 86. The specific structure is as follows :

The cylindrical rod 82 and the conical head 86 in close contact are arranged up and down to pass through the conical head sleeve 83; the upper side of the conical head sleeve 83 is provided with an upper fastening bolt hole 84, and the upper fastening bolt is installed on the upper fastening bolt Bolt holes 84, the cylindrical rod 82 is fixed on the conical head sleeve 83 through the upper fastening bolts; the lower side of the conical head sleeve 83 is provided with lower fastening bolt holes 85, and the lower fastening bolts are installed on the lower fastening bolts The bolt hole 85 and the conical head 86 are a structure in which the cylindrical section and the conical section are integrated up and down. The lower end of the tapered section corresponds to the tubular sample 14 to be scratched. The contact sensor 81 is installed on the cylindrical rod 82 to expose the upper side of the conical head sleeve 83. When the conical head 86 touches the tubular sample 14, the contact sensor 81 gives a signal feedback, which is used as the adjustment zero point of the scale 9. The lower end of the ruler 9 is connected to the upper end of the cylindrical rod 82, and the scratch depth of the tapered head 86 is adjusted up and down through the ruler 9 to realize the quantitative preset of the scratch depth.

Among them, the conical head has various angle specifications and is made of YG series cemented carbide, so as to realize the preparation of surface linear scratch samples with different scratch angles. The cylindrical rod is made of TWIP steel, which has the characteristics of high strength and high rigidity, which ensures that almost no deformation occurs during the linear scratching process, thereby ensuring quantitative accuracy.

As shown in Figure 1-Figure 5, the method of using the tubular sample quantitative linear scratching device of the present invention is as follows:

1. Select the conical head 86 matching the required scratch angle, and install the conical head 86 into the conical head sleeve 83. During the installation process, pay attention to closely cooperate with the cylindrical rod 82, and fully press upwards. The tightening bolt holes 85 and the upper tightening bolt holes 84 are tightened.

2. Fix the tubular sample 14, carefully insert the tubular sample 14 into the clamping and fixing tube sleeve 16, and place it on the sample stand 15; rotate the turntable 71, and continuously press down the V-shaped pressing block 75, and press it tightly. Tubular sample 14 until the tubular sample 14 cannot freely rotate and move back and forth.

3. Connect the power supply 1 with 220V power supply, adjust the frequency of the inverter 2 (0~100Hz) to make it reach the scratch rate required for the preparation (adjust as needed), press the "forward" button of the inverter 2, turn the cone Directly below the head 86 is aligned with the tubular sample 14 .

4. Move downward through the ruler 9 until the conical head 86 at the lower end of the scratching mechanism 8 touches the highest point on the surface of the tubular sample 14, and the contact sensor 81 emits a beep. The entire scratching mechanism 8 is fixed at this height, and the scale 9 is reset to zero. This position is regarded as the starting point of feeding for quantitative scratching, and the indication of the scale 9 at this time is taken as the zero point.

5. Press the "Reverse" button of the inverter 2 to move the conical head 86 out of the top of the tubular sample 14. Adjust the scale 9 from the zeroing point to the required scratch depth, and then tighten the locking bolt 11.

6. To prepare scratches, press the "forward" button of the inverter 2, the straight motor 3 pushes the transmission rod 4 to move forward, and the tubular sample 14 is linearly scratched by the conical head 86 to complete the scratch preparation.

7. Press the "stop" button of the inverter 2, loosen the locking bolt 11, raise the ruler 9, loosen the rotary disk 71, and take out the tubular sample 14 with the required surface linear scratches.

The results show that the invention adjusts the scratch angle by replacing the conical heads with different angles; moves the ruler up and down, cooperates with the contact sensor to reset to zero, and adjusts the scratch depth; controls the frequency of the straight motor by the frequency converter to adjust the scratch depth injury rate. The device can realize quantitative surface linear scratching of tubular samples, and supports the adjustment of parameters such as various scratch angles, various scratch depths, and various scratch speeds to simulate the preparation of surface linear scratch samples.

Claims (10)

1. A quantitative linear scratching device for tubular samples is characterized in that a fixing pipe sleeve for a card, a sample platform, a guide groove and a scratching frame are arranged on a main frame, the main frame comprises a main frame side plate and a main frame platform, the main frame side plate is vertically arranged on one side of the main frame platform, the fixing pipe sleeve for the card is arranged in the middle of one side of the main frame side plate, the sample platform is arranged on the main frame platform on one side of the main frame side plate, the tubular samples are arranged on an arc-shaped groove on the upper surface of the sample platform, two gantry pressure pipe fixing devices which are arranged on the top of the tubular samples in a relatively parallel mode are arranged on the sample platform, each gantry pressure pipe fixing device corresponds to the tubular sample through a V-shaped groove at the bottom of a V-shaped pressing block on the gantry pressure pipe fixing device, the arc-shaped groove on the upper surface of, one end of the tubular sample is inserted into the clamping and fixing pipe sleeve;

the scratch frame is of a structure with a cantilever at the upper end of a single stand column, a locking mechanism, a guide block and a scratch mechanism are sequentially arranged at the end part of the cantilever from top to bottom, the guide block is provided with the locking mechanism, the upper end of the scratch mechanism is provided with a standard square, the standard square sequentially penetrates through the guide block and the strip-shaped locking mechanism and is in sliding fit with the guide block and the strip-shaped locking mechanism, a locking bolt is arranged in a side opening of the locking mechanism, the locking bolt and the standard square are locked and positioned, and a conical head corresponding to the surface of a tubular sample is arranged at the lower end of the scratch mechanism; the lower end of the single upright post is arranged in a guide groove on the other side of the main frame platform, the guide groove and the tubular sample are in the same horizontal direction, and one end of the transmission rod extends into the guide groove and is connected with the lower end of the single upright post.

2. The tubular specimen quantitative linear scoring device according to claim 1, wherein the other end of the drive link is connected to a linear motor, the linear motor is connected to a power source through a frequency converter, and the scoring frame is driven by the linear motor, the scoring frame driving the scoring mechanism to move linearly.

3. The tubular sample quantitative linear scratching device according to claim 1, wherein the frequency of the frequency converter is adjustable within the range of 0 to 100Hz, so as to realize different linear speed control of the scratching mechanism during the preparation process.

4. The quantitative linear scratching device for tubular specimens according to claim 1, wherein buffer cotton is disposed at the sample rack and the contact point where the tubular specimen is clamped by the gantry pressure tube fixing device in order to protect the original surface state of the tubular specimen.

5. The tubular sample quantitative linear scratching device according to claim 1, wherein the gantry pressing pipe fixing device comprises a rotary disc, a screw, a gantry, a chute and a V-shaped pressing block, and the device has the following specific structure:

the middle of the top of the portal frame is provided with a threaded hole, a vertically arranged screw rod penetrates through the threaded hole, the upper end of the screw rod is integrally connected with the rotary disc, the lower end of the screw rod is connected with the V-shaped pressing block through a bearing, two sides of the V-shaped pressing block are in sliding fit with vertical sliding grooves in the portal frame, and a V-shaped groove corresponding to the tubular sample is formed in the bottom of the V-shaped pressing block.

6. A quantitative linear scratching device for tubular specimens according to claim 5, wherein in use, two gantry pressure tube fixing devices are fixed on a specimen holder with an arc-shaped groove, and the gantry pressure tube fixing devices are integrally connected with the specimen holder, so as to fix the tubular specimens.

7. The quantitative linear scratching device for tubular specimens according to claim 1, wherein the scratching mechanism is composed of a contact sensor, a cylindrical rod, a conical head sleeve, an upper fastening bolt hole, a lower fastening bolt hole and a conical head, and is specifically structured as follows:

the upper part and the lower part of the contact sensor are provided with a cylindrical rod which is in close contact with the conical head, the conical head penetrates through the conical head sleeve, and the contact sensor is arranged on the side surface of the upper part of the cylindrical rod, which is exposed out of the conical head sleeve; the side surface of the upper part of the conical head sleeve is provided with an upper fastening bolt hole, an upper fastening bolt is arranged in the upper fastening bolt hole, and the cylindrical rod is fixedly propped against the conical head sleeve through the upper fastening bolt; the side surface of the lower part of the conical head sleeve is provided with a lower fastening bolt hole, a lower fastening bolt is arranged on the lower fastening bolt hole, the conical head is of a structure integrating a cylindrical section and a conical section into a whole from top to bottom, the cylindrical section of the conical head is tightly fixed on the conical head sleeve through the lower fastening bolt, and the lower end of the conical section of the conical head corresponds to a tubular sample to be scratched.

8. The quantitative linear scratching device for the tubular test sample according to claim 7, wherein the lower end of the standard square is connected with the upper end of the cylindrical rod, and the quantitative presetting of the scratching depth is realized by adjusting the scratching depth of the conical head up and down through the standard square; when the conical head contacts the tubular sample, the contact sensor generates signal feedback, and the signal feedback is used as an adjustment zero point of the moment ruler.

9. The apparatus for quantitative linear scoring of tubular specimens according to claim 7, wherein the conical head is made of YG series cemented carbide and the cylindrical shaft is made of TWIP steel.

10. The use method of the quantitative linear scratching device for the tubular test sample as claimed in any one of claims 1 to 9, which is characterized by comprising the following specific steps:

(1) selecting a conical head matched with a required preparation scratch angle, installing the conical head into a conical head sleeve, closely matching the conical head with a cylindrical rod in the installation process, completely jacking upwards, and fastening through a lower fastening bolt hole and an upper fastening bolt hole;

(2) fixing a tubular sample, inserting the tubular sample into a clamping and fixing pipe sleeve, and placing the tubular sample on a sample stand; rotating the rotary disc, continuously pressing the V-shaped pressing block down to press the tubular sample until the tubular sample cannot freely rotate and move back and forth;

(3) a 220V power supply is connected with a power supply, the frequency of the frequency converter is adjusted to reach the required scratching speed, a forward button of the frequency converter is pressed, and the position right below the conical head is aligned to the tubular sample;

(4) the moment scale moves downwards until the conical head at the lower end of the scratching mechanism contacts the highest point of the surface of the tubular sample, the contact sensor gives out a prompt sound, the locking bolt is screwed at the moment, the whole scratching mechanism is fixed at the height, and the moment scale is reset to zero;

(5) pressing a 'reverse' button of the frequency converter to move the conical head out of the upper part of the tubular sample; adjusting the standard square to the scratch depth required to be prepared, and then screwing the fastening bolt;

(6) preparing a scratch, pressing a forward button of a frequency converter, pushing a transmission rod to move forward by a linear motor, and linearly scratching a tubular sample by a conical head to finish scratch preparation;

(7) and pressing a stop button of the frequency converter, loosening the locking bolt, lifting the standard square, loosening the rotary disc, and taking out the tubular sample with the linear scratch on the required surface.

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