Method for determining defects by comparing reference object translation secondary radiography

Abstract

The invention belongs to the technical field of nondestructive testing, and discloses a method for determining defects through translation secondary radiography of a contrast reference object, which specifically comprises the following steps: S1, appearance inspection; s2, preparing for radiographic inspection; s3, training the ray machine; s4, performing ray shooting inspection; s5, processing the film in a darkroom; and S6, negative film evaluation. The method has the advantages of simplicity, convenience and rapidness, realizes defect depth measurement, can be well applied to practical engineering, and efficiently guides practical work.

Description

Technical Field

[0001] The present invention belongs to the technical field of non-destructive testing, and particularly relates to a method for determining defects by translating a comparison reference object for secondary radiography. Background Art

[0002] In recent years, with the rapid development of non-destructive testing technology, radiography technology has been widely used in industries such as weapons, aerospace, aviation, and ships. The rays are mainly used to detect whether there are defects inside the workpiece. After detecting defects in the workpiece through rays, it is necessary to further determine the position of the defects inside the workpiece, and finally use the negative film to evaluate the defects, complete the qualitative and quantitative analysis of the defects, ensure the accurate judgment of the defects inside the workpiece, determine what kind of quality hazards the defects cause to the workpiece, facilitate the elimination of defect generation from the processes such as design and processing, and ensure the product quality. To sum up, it is necessary to determine not only the nature and size of the defects, but also the position of the defects in the workpiece. However, for radiography technology, since the negative film directly gives the position of the defects on the radiographic plane and cannot determine the specific position of the defects in the workpiece, it is still necessary to further determine the position of the defects in the workpiece. Currently, the ray photo detection technology cannot determine the position of the defects in the workpiece.

[0003] Therefore, there is an urgent need to develop a brand-new radiography detection method to overcome the problems existing in the prior art. Summary of the Invention

[0004] The technical problem to be solved by the present invention is that the existing radiography technology can only detect the position of the defects on the radiographic plane and cannot directly determine the specific spatial position of the defects in the workpiece.

[0005] To solve the above technical problem, the specific technical solution of the present invention is as follows:

[0006] A method for determining defects by translating a comparison reference object for secondary radiography, specifically including the following steps:

[0007] S1. Appearance inspection;

[0008] S2. Preparation before ray detection;

[0009] S3. Training the ray machine;

[0010] S4. Ray film inspection;

[0011] S5. Processing the film in the darkroom;

[0012] S6. Evaluation of the negative film.

[0013] Further, S1 specifically includes the following steps:

[0014] S101. Clean the impurities on the surface of the workpiece to ensure that there are no sundries on the surface of the workpiece that affect radiography;

[0015] S102. Inspect the surface of the workpiece to identify obvious defects or damages, specifically including checking the surface finish, flatness of the workpiece, and whether there are cracks, dents, rust or other visible defects on the workpiece.

[0016] Furthermore, S2 specifically includes the following steps:

[0017] S201. Film preparation: Cut the radiographic film with a slicer in a darkroom, load it into a cassette, and seal both ends of the cassette with adhesive tape for standby;

[0018] S202. Select the type of ray machine: Select a directional machine according to the form of the workpiece;

[0019] S203. Install the ray machine: Install the directional tube of the ray machine to make the central line of the ray source irradiation perpendicular to the ground, connect the high-voltage cable, search for relevant specifications, and select the focal length according to the thickness of the workpiece;

[0020] S204. Turn on the power: Turn on the power, start the exhaust fan, and close the radiation lead door.

[0021] Furthermore, S3 specifically includes the following steps:

[0022] S301. Select the directional light tube for the ray tube;

[0023] S302. Select the standard focus and point the position of the focus device at the large / small focus;

[0024] S303. Turn on the cooling power switch, start the cooling oil pump, and the ray tube cooling system works;

[0025] S304. Adjust the voltage meter, ammeter and timer according to the training machine program to train the ray machine;

[0026] After the training of the ray machine is completed, adjust the voltage meter, ammeter and timer according to the specifications to meet the required voltage (Kv), current (mA) and exposure time (min) of the specifications;

[0027] S306. Turn on the high-voltage switch of the ray machine, the high-voltage indicator light is on, start the high-voltage button of the ray machine, the warning indicator light is on, the warning duration is 1 - 3s, the flash light keeps flashing during high voltage until the exposure time drops to zero, and the high voltage automatically disconnects;

[0028] S307. Turn on the cooling power switch of the ray machine to make the cooling pump continue to work. After the ray tube is cooled for 3 - 8 minutes, turn off the machine and wait for radiographic film inspection.

[0029] Furthermore, S4 specifically includes the following steps:

[0030] S401. Bring the spare radiographic film into the exposure room;

[0031] S402. Place the film on the predetermined exposure lead plate. Align the workpiece with the beam center of the radiation source according to the single-wall single-image exposure process, and offset the film appropriately along the exposure direction;

[0032] S403. Arrange the reference lead marker at the vertical position of the radiation source, and place the image quality indicator on the surface of the workpiece near the radiation source side;

[0033] S404. In the predetermined exposure field, place the workpiece, film, image quality indicator, and reference lead marker in accordance with the regulations, and close the radiation lead door;

[0034] S405. Set relevant exposure parameters such as tube voltage, tube current, exposure time, focal length, and focus according to the exposure process and standards;

[0035] S406. Operate the control console to turn on the ray machine to complete the first radiographic inspection at the position of the radiation source S1;

[0036] S407. After the first radiographic inspection is completed, open the lead door, take out the film of the first exposure, and arrange a new film. Then, place the workpiece, film, image quality indicator, and reference lead marker in accordance with the radiographic standards and specifications. Horizontally move the radiation source from the position of S1 to the position of the radiation source S2 for the second radiographic inspection. Close the lead door, start the exhaust system, and start the ray to complete the second radiographic inspection;

[0037] S408. After the filming is completed, open the lead door, take out the film on which the radiographic inspection is completed, and further process it in the darkroom.

[0038] Furthermore, S5 specifically includes the following steps:

[0039] S501. Close the doors and windows of the darkroom and the exposure curtain, turn off the white light, turn on the safety red light, and under the dark red light, open the dark bag containing the film and take out the film;

[0040] S502. Turn on the power switch of the automatic film processor, send the film into the film inlet of the automatic film processor, and the film passes through the processes of developing, fixing, washing with water, and drying in sequence, and a film with good processing quality is sent out from the film outlet of the film processor.

[0041] Furthermore, S6 specifically includes the following steps:

[0042] S601. Place the film on the viewbox and mark the nature and size of the defects on the film with a marker pen;

[0043] S602. Defect position measurement: For the first radiographic inspection, the radiation source is at position A1, and the radiation penetrates the workpiece. Among them, A1Q passes through the reference lead marker, and A1P1 passes through the internal defect of the workpiece. Take the direction perpendicular to the film where the radiation of the first radiation source A1 passes through the reference lead marker as the Y-axis, and the horizontal direction at the bottom of the film as the X-axis, and the intersection point of the two is taken as the 0 point;

[0044] S603. Second radiographic inspection: After horizontally moving the radiation source A1 to the position of the radiation source A2, the displacement is recorded as ΔA. The radiation source is at position A2, and the radiation penetrates the workpiece. A2P2 passes through the internal defect of the workpiece, and the intersection point with the film in the horizontal direction is taken as A2P2;

[0045] S604. Determine the position of the defect by the geometric method:

[0046] A1 and A2 are the positions of the radiation sources for the two radiographic inspections;

[0047] ΔA is the distance of the translation of the radiation source between the two radiographic inspections;

[0048] A1P1 and A2P2 are the images of the defect in the second radiographic inspection;

[0049] ΔP is the distance of the defect between the two radiographic inspections;

[0050] A1P1 is the horizontal distance from the image of the defect in the first radiographic inspection to the reference lead marker;

[0051] F is the distance from the radiation source to the film;

[0052] P is the position of the defect in the workpiece;

[0053] From the processed film, it is known that: A1P1A2P2 = ΔP, A1A2 = ΔA, OA1P1 = P1

[0054] According to the geometric relationship:

[0055]

[0056] Similarly, according to the geometric relationship:

[0057]

[0058] Combining equations (1) and (2), we get

[0059] It is solved that the position of the defect P is

[0060] Furthermore, a lead plate with an appropriate thickness is provided at the bottom of the film, and the thickness of the lead plate is not less than 4 mm.

[0061] Further, when arranging the radiation field, the image quality indicator is arranged on the radiation source side of the workpiece; the metal wire of the image quality indicator should be the same as the material of the workpiece to be tested.

[0062] The present invention has the following advantages: The method of using a comparison reference object to translate for secondary radiographic testing has the advantages of simplicity, convenience, and speed, can achieve defect depth determination, can be well applied to actual engineering, and can efficiently guide practical work. Description of the Drawings

[0063] Figure 1 It is a schematic diagram of a method for designing a comparison reference object translation secondary radiographic testing for defect determination provided by an embodiment of the present invention;

[0064] Figure 2 It is a schematic flow diagram of a method for using a comparison reference object to translate for secondary radiographic testing for defect determination provided by an embodiment of the present invention.

[0065] In the figure: 1, radiation source; 2, reference lead marker; 3, image quality indicator; 4, defect; 5, workpiece; 6, film. Detailed Embodiment

[0066] In order to better understand the purpose, structure, and function of the present invention, the following further detailed description of the present invention is made in conjunction with the drawings.

[0067] As Figure 1 shown, it is a schematic diagram of a method for designing a comparison reference object translation secondary radiographic testing for defect determination of the present invention; it includes a radiation source (1), a reference lead marker (2), an image quality indicator (3), a defect (4), a workpiece (5), and a film (6). Among them, the reference lead marker (2) is placed on the same vertical line as the radiation source (1), and the reference lead marker (2) is closely attached to the surface of the workpiece (5); the image quality indicator (3) is arranged on the surface of the workpiece (5) and close to the side of the radiation source (1), mainly used to detect the quality of the film image; the bottom of the workpiece (5) is closely attached to the film (6), and a lead plate is provided at the bottom of the film (6), mainly used to filter out useless scattered rays.

[0068] Refer to Figure 2 , Figure 2 It is a schematic flow diagram of a method for using a comparison reference object to translate for secondary radiographic testing for defect determination provided by an embodiment of the present invention. A method for using a comparison reference object to translate for secondary radiographic testing for defect determination is as follows:

[0069] S1 Appearance inspection, specifically including the following steps:

[0070] S101 Clean the impurities on the surface of the workpiece to ensure that there are no sundries on the surface of the workpiece that affect radiographic testing;

[0071] S102 Inspect the surface of the workpiece to identify obvious defects or damages, specifically including inspecting the surface finish, flatness of the workpiece, and whether there are cracks, dents, rust or other visible defects on the workpiece.

[0072] S2 Prepare for ray detection, specifically including the following steps:

[0073] S201 Film preparation: Cut the ray film with a slicer in a darkroom, load it into a cassette, and seal both ends of the cassette with adhesive tape for standby;

[0074] S202 Select the type of ray machine: Select a directional machine according to the form of the workpiece;

[0075] S203 Install the ray machine: Install the directional tube of the ray machine so that the central axis of the ray source is perpendicular to the ground, connect the high-voltage cable, search for relevant specifications, and select the focal length according to the thickness of the workpiece;

[0076] S204 Turn on the power: Turn on the power, start the exhaust fan, and close the radiation lead door;

[0077] S3 Train the ray machine, specifically including the following steps:

[0078] S301 Ray tube selection, select a directional light tube;

[0079] S302 Select the focus, select the standard focus, and point the position of the focus finder at the large / small focus;

[0080] S303 Turn on the cooling power switch, start the cooling oil pump, and the ray tube cooling system works;

[0081] S304 According to the training program of the ray machine, adjust the voltage meter, ammeter and timer to train the ray machine;

[0082] S305 After the training of the ray machine is completed, adjust the voltage meter, ammeter and timer according to the specifications to meet the required voltage (Kv), current (mA) and exposure time (min) of the specifications;

[0083] S306 Turn on the high-voltage switch of the ray machine, the high-voltage indicator light is on, start the high-voltage button of the ray machine, the warning indicator light is on, the warning duration is (from 1 to 3 s), the flash lamp flashes continuously during high voltage until the exposure time drops to zero, and the high voltage automatically disconnects;

[0084] S307 Turn on the cooling power switch of the ray machine to make the cooling pump continue to work. After the ray tube is cooled (for 3 - 8 min), turn off the machine and wait for radiographic film inspection;

[0085] S4 Radiographic film inspection, specifically including the following steps:

[0086] S401 Bring the standby ray film into the exposure room;

[0087] In S402, place the film on the predetermined radiographic lead plate. Align the workpiece with the beam center of the radiation source according to the single-wall single-image radiography process, and offset the film appropriately along the radiographic direction.

[0088] In S403, arrange the reference lead markers at the vertical position of the radiation source, and place the image quality indicator on the surface of the workpiece near the radiation source side.

[0089] In S404, place the workpiece, film, image quality indicator, and reference lead markers properly within the predetermined radiographic field, and close the radiation lead door.

[0090] In S405, set relevant radiographic parameters such as tube voltage, tube current, exposure time, focal length, and focus according to the radiographic process and standards.

[0091] In S406, operate the control console to turn on the ray machine to complete the first radiographic inspection at the position of the radiation source S1.

[0092] In S407, after the first radiographic inspection is completed, open the lead door and take out the film of the first radiograph. Then arrange a new film, and place the workpiece, film, image quality indicator, and reference lead markers properly according to the radiographic standards and specifications. Move the radiation source horizontally from the position of S1 to the position of the radiation source S2 for the second radiographic inspection. Close the lead door, start the exhaust system, and start the ray to complete the second radiographic inspection.

[0093] In S408, after the filming is completed, open the lead door, take out the film on which the radiograph is completed, and further process it in the darkroom.

[0094] In S5, process the film in the darkroom, which specifically includes the following steps:

[0095] In S501, close the doors and windows of the darkroom and the radiographic curtain, turn off the white light, turn on the safety red light, and in the dark red light, open the dark bag containing the film and take out the film.

[0096] In S502, turn on the power switch of the automatic film processor, send the film into the film inlet of the automatic film processor, and the film passes through the processes of developing, fixing, washing, and drying in sequence, and a film with good processing quality is sent out from the film outlet of the film processor.

[0097] In S6, evaluate the negative film, which specifically includes the following steps:

[0098] In S601, place the film on the viewbox, carefully evaluate it, and mark the nature and size of the defects on the film with a marker pen.

[0099] The measurement of the S602 defect position is as follows: For the first radiographic inspection, the radiation source is at the position A1. The radiation penetrates the workpiece. Among them, A1Q passes through the reference lead marker, and A1P1 passes through the internal defect of the workpiece. Taking the direction perpendicular to the film where the radiation of the first radiation source A1 passes through the reference lead marker as the Y-axis and the horizontal direction at the bottom of the film as the X-axis, the intersection point of the two is taken as the 0 point;

[0100] For the second radiographic inspection in S603, after horizontally moving the radiation source A1 to the position of the radiation source A2, the displacement is recorded as ΔA. When the radiation source is at the position A2, the radiation penetrates the workpiece, and A2P2 passes through the internal defect of the workpiece. The intersection point with the film in the horizontal direction is taken as A2P2;

[0101] S604 Determine the position of the defect by the geometric method:

[0102] In the figure, A1 and A2 are the positions of the radiation sources for the two radiographic inspections;

[0103] ΔA is the distance of the translation of the radiation source between the two radiographic inspections;

[0104] A1P1 and A2P2 are the images of the defect in the second radiographic inspection;

[0105] ΔP is the distance of the defect between the two radiographic inspections;

[0106] A1P1 is the horizontal distance from the image of the defect in the first radiographic inspection to the reference lead marker;

[0107] F is the distance from the radiation source to the film;

[0108] P is the position of the defect in the workpiece;

[0109] Through the processed film, it is known that: A1P1A2P2 = ΔP, A1A2 = ΔA, OA1P1 = P1

[0110] According to the geometric relationship, there is:

[0111]

[0112] ]>Similarly, according to the geometric relationship, there is:

[0113]

[0114] Combining equations (1) and (2), we get ]>

[0115] It is solved that the position of the defect P is

[0116] From equation (3), the position of the internal defect can be obtained, which further provides a judgment basis for the determination of the internal defect of the workpiece.

[0117] Preferably, a lead plate with an appropriate thickness is provided at the bottom of the film, and the thickness of the lead plate is not less than 4 mm, which is mainly used to reduce the generation of useless rays and absorb the scattered rays that may be generated.

[0118] Preferably, when arranging the radiographic field, the image quality indicator is arranged on the radiation source side of the workpiece; the metal wire of the image quality indicator should be the same as or similar to the material of the workpiece to be tested.

[0119] Preferably, the ray machine training machine only absorbs the gas in the pipeline to improve the vacuum degree of the ray tube; the ray machine training machine gradually increases the voltage from low voltage and low current according to a certain program until the rated voltage required for the operation of the ray machine is reached.

[0120] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, for those skilled in the art, without departing from the principle of the present invention, several deformations and improvements can still be made, and these should also be regarded as belonging to the protection scope of the present invention.

Claims

1. A method for determining defects by means of secondary radiography with translation of a comparison reference object, characterized in that Specifically, it includes the following steps: S1. Appearance inspection; S2. Preparation for ray detection; S3. Training of the ray machine; S4. Ray radiography inspection; S5. Darkroom processing of the film; S6. Evaluation of the negative film.

2. The method for defect determination by translation of a comparison reference object in secondary radiography according to claim 1, characterized in that, S1 specifically includes the following steps: S101. Clean the impurities on the surface of the workpiece to ensure that there is no debris on the workpiece surface that affects radiography; S102. Inspect the surface of the workpiece to identify obvious defects or damages, specifically including checking the surface finish, flatness of the workpiece, and whether there are cracks, dents, rust or other visible defects on the workpiece.

3. The method for determining defects by translating a contrast reference object in secondary radiography according to claim 2, wherein S2 specifically includes the following steps: S201. Film preparation: Cut the ray film with a slicer in the darkroom, load it into the cassette, and seal both ends of the cassette with adhesive tape for standby; S202. Select the type of ray machine: Select a directional machine according to the form of the workpiece; S203. Install the ray machine: Install the directional tube of the ray machine so that the irradiation center line of the ray source is perpendicular to the ground, connect the high-voltage cable, search for relevant specifications, and select the focal length according to the thickness of the workpiece; S204. Turn on the power: Turn on the power, start the exhaust fan, and close the radiation lead door.

4. The method for detecting defects by translating a contrast reference object in secondary radiography according to claim 3, characterized in that, S3 specifically includes the following steps: S301. Select the directional light tube for the ray tube; S302. Select the standard focus and point the position of the focus device at the large / small focus; S303. Turn on the cooling power switch, start the cooling oil pump, and the ray tube cooling system works; S304. According to the training machine program, adjust the voltage meter, ammeter and timer to train the ray machine; S305. After the training of the ray machine is completed, adjust the voltage meter, ammeter and timer according to the specifications to meet the required voltage (Kv), current (mA) and exposure time (min) of the specifications; S306. Turn on the high-voltage switch of the ray machine, the high-voltage indicator light is on, start the high-voltage button of the ray machine, the warning indicator light is on, the warning duration is 1-3s, the flash light keeps flashing during high voltage, flashes until the exposure time drops to zero, and the high voltage automatically disconnects; S307. Turn on the cooling power switch of the ray machine to make the cooling pump continue to work. After the ray tube is cooled for 3-8 minutes, turn off the machine and wait for ray radiography inspection.

5. The method for defect determination by translating a contrast reference object in secondary radiography according to claim 4, characterized in that, S4 specifically includes the following steps: S401. Bring the spare ray film into the exposure room; S402. Place the film on the predetermined exposure lead plate, align the workpiece with the beam center of the ray source according to the single-wall single-image exposure process, and offset the film appropriately along the exposure direction; S403. Place the reference lead marker in the vertical position of the ray source, and place the image quality indicator on the surface of the workpiece close to the ray source side; S404. In the predetermined exposure field, place the workpiece, film, image quality indicator and reference lead marker properly according to the regulations, and close the radiation lead door; S405. Set the relevant exposure parameters such as tube voltage, tube current, exposure time, focal length, focus, etc. according to the exposure process and standards; S406. Operate the control console to turn on the ray machine to complete the first ray radiography inspection at the S1 position of the ray source; S407. After the first radiographic inspection is completed, open the lead door, take out the first radiographic film, arrange a new film, and arrange the workpiece, film, image quality indicator, and reference lead marker in accordance with the radiographic standards and specifications. Horizontally move the radiation source from position S1 to radiation source position S2, conduct the second radiographic inspection, close the lead door, start the exhaust system, start the radiation, and complete the second radiographic inspection; S408. After the radiograph is completed, open the lead door, take out the radiographic film, and further process it in the darkroom.

6. The method for determining defects by translating a contrast reference object in secondary radiography according to claim 5, characterized in that, S5 Specifically includes the following steps: S501. Close the doors and windows of the darkroom and the radiographic curtain, turn off the white light, turn on the safety red light, and under the dark red light, open the dark bag containing the film and take out the film; S502. Turn on the power switch of the automatic film processor, send the film into the film inlet of the automatic film processor, and the film sequentially passes through the processes of developing, fixing, washing, and drying, and a film with good processing quality is sent out from the film outlet of the film processor.

7. The method for measuring defects by translation of a contrast reference object in secondary radiography according to claim 6, characterized in that, S6 Specifically includes the following steps: S601. Place the film on the viewing lamp, and use a marker pen to mark the nature and size of the defects on the film; S602. Defect position measurement: For the first radiographic inspection, the radiation source is at position A1, the radiation penetrates the workpiece, where A1Q passes through the reference lead marker, and A1P1 passes through the internal defect of the workpiece. Take the direction perpendicular to the film where the radiation of the first radiation source A1 passes through the reference lead marker as the Y-axis, and the horizontal direction at the bottom of the film as the X-axis, and the intersection point of the two is taken as the 0 point; S603. Second radiographic inspection: After horizontally moving the radiation source A1 to the radiation source position A2, the displacement is recorded as ΔA. When the radiation source is at position A2, the radiation penetrates the workpiece, and A2P2 passes through the internal defect of the workpiece, and the intersection point with the film in the horizontal direction is taken as A2P2; S604. Determine the position of the defect by the geometric method: A1 and A2 are the positions of the radiation sources for the two radiographic inspections; ΔA is the distance of the translation of the radiation source between the two radiographic inspections; A1P1 and A2P2 are the images of the defect in the second radiographic inspection; ΔP is the distance of the defect between the two radiographic inspections; A1P1 is the horizontal distance from the image of the defect in the first radiographic inspection to the reference lead marker; F is the distance from the radiation source to the film; P is the position of the defect in the workpiece; From the processed film, it is known that: A1P1A2P2 = ΔP, A1A2 = ΔA, OA1P1 = P1 According to the geometric relationship: Similarly, according to the geometric relationship: Combining equations (1) and (2), we get The position of defect P is solved as 8. The method for measuring defects by means of translation of a contrast reference object in secondary radiography according to claim 7, characterized in that, A lead plate with an appropriate thickness is provided at the bottom of the film, and the thickness of the lead plate is not less than 4 mm.

9. The method for detecting defects by means of translation of a contrast reference object in secondary radiography according to claim 8, characterized in that, When arranging the radiographic field, the image quality indicator is arranged on the radiation source side of the workpiece; the metal wire of the image quality indicator should be the same as the material of the workpiece to be tested.

Images