Welding seam detection method of pipe ring part based on source outside vertical transillumination single-wall single image

Abstract

The invention discloses a welding seam detection method for a pipe ring part based on a source outside vertical transillumination single-wall single image, and the method comprises the steps: determining the transillumination times N and one-time effective transillumination length L of a corresponding pipe ring part according to a radiographic inspection standard GJB1187A; the pipe ring part is placed in the effective transillumination area, the pipe ring part is placed on two arc-shaped seats with the same radian, then the pipe ring part is fixed through an indexing disc, two reference circle parallel shafts parallel to the pipe ring part are installed on the peripheral side of the indexing disc, and the area between every two adjacent reference circle parallel shafts is the area for single exposure observation; then, a film detection system tool corresponds to the corresponding transillumination length L, the film detection system tool is inserted into the pipe ring part in parallel, and a lead sheath is arranged at the position, corresponding to the weld joint, of the film detection system tool in the pipe ring part; and 360-degree film type source external single-wall transillumination ray detection is carried out on the pipe ring part by rotating the film detection system tool and rotating the turntable on the indexing disc. According to the invention, the problems of long workpiece detection time, large workload, low efficiency, poor stability and the like in existing detection are solved, and the method has good practicability.

Description

Technical Field

[0001] The invention belongs to the technical field of ray detection of weld parts, and in particular relates to a weld detection method for pipe ring parts based on external vertical irradiation of a single wall and single shadow by a source. Background Art

[0002] At present, small diameter pipe girth welds generally refer to pipe welds with an outer diameter of ≤100mm. Such small diameter pipe girth weld parts are widely used in the power, petrochemical, aviation and other industries. In aircraft manufacturing, aircraft maintenance, missiles and other aircraft manufacturing, small diameter pipe girth weld parts are important parts of flight control systems and hydraulic systems such as aviation boosters, actuators, and accumulators. Small diameter pipe girth weld parts are mainly used for the transportation of oil, combustible gas, steam and reaction liquids, heat exchange and cooling piping and connecting pipes, aviation actuators, aviation hydraulic parts, etc. A large part of them work in harsh environments of high temperature and high pressure corrosive media, and the welds are the weak links in the parts. Once leakage or damage occurs, the losses are very huge. Film radiography is one of the most widely used and mature means of small diameter pipe girth welds.

[0003] Small diameter pipe ring weld is a special workpiece with large penetration ratio. Its weld radiography is a special variable cross-section work radiography problem. The radiography methods currently used are elliptical imaging penetration method (double wall double shadow method) and source outside vertical penetration single wall single shadow method. For aviation parts, the source outside vertical penetration single wall single shadow method should be preferred, because the penetration thickness of the source outside vertical penetration single wall single shadow method is single wall, while the penetration thickness of the elliptical imaging penetration method is double wall. In terms of sensitivity, the source outside vertical penetration single wall single shadow method has more advantages. For example, when the double wall double shadow is used for the ring weld with a wall thickness of 8mm, the penetration wall thickness is 16mm. The single wall image quality index that needs to be found during A-level detection is #13 wire. However, the double wall image quality index that needs to be found during A-level detection is #12 wire. In terms of sensitivity, the sensitivity of single wall penetration is higher than that of double wall double shadow. When double-wall radiography is performed on small-diameter pipe welds, the large change in radiographic thickness leads to large changes in image blackness and geometric unsharpness. In addition, the image opening width needs to be adjusted for double-wall and double-image radiography, and the image opening width directly affects the observable image quality. More importantly, when radiography is performed at a relatively low radiographic thickness, the selected voltage must be relatively low, resulting in a larger △D (image contrast). Therefore, when radiographic conditions permit, the single-wall and single-image method with the source externally vertically should be used as the priority.

[0004] When the source is externally vertically transilluminating a single wall and a single shadow method is used, the radiation source is placed on the center line of the weld during transillumination, and the central beam of radiation points vertically to the center of the weld area being transilluminated. A lead plate must be placed on the back of the film to shield the scattered rays from other parts of the inner wall of the workpiece. However, the use of the source externally vertically transilluminating a single wall and a single shadow method will involve the following corresponding problems: relying on manual placement of film and lead sheets, a large workload, low efficiency, and a large number of feedback from workers, which will lead to inaccurate positioning, lead sheets, and film shedding, resulting in repeated transillumination rework and other problems, unclear imaging, and greater human influence, and extremely poor stability. In addition, only one weld can be transilluminated at a time, resulting in low work efficiency. Summary of the invention

[0005] The purpose of the present invention is to provide a weld detection method for pipe ring parts based on external vertical single-wall single-shadow radiographic source, aiming at performing radiographic detection efficiently and conveniently.

[0006] The present invention is mainly achieved through the following technical solutions: The weld detection method of a pipe ring part based on a source vertically penetrating a single wall and a single shadow outside includes the following steps: Step S1: According to the radiographic inspection standard GJB1187A, determine the number of times N of exposure and the effective exposure length L of the corresponding pipe ring parts; Step S2: placing the pipe ring part in the effective transillumination area, placing the pipe ring part on two arc-shaped seats with equal arcs, and then fixing the pipe ring part with a dividing disk, wherein the circumferential side of the dividing disk is provided with two dividing circle parallel axes parallel to the pipe ring part, and the area between two adjacent dividing circle parallel axes is the single exposure observation area; Step S3: Then, the corresponding exposure length L of the film detection system tooling is used, and the film detection system tooling is inserted into the pipe ring part in parallel, and lead foil is set at the corresponding weld of the film detection system tooling inside the pipe ring part; by rotating the film detection system tooling and rotating the turntable on the dividing disk, 360° film-type source external single-wall exposure X-ray detection of the pipe ring part is realized.

[0007] In order to better realize the present invention, further, in the step S1, according to the requirements and grade requirements of the standards such as GJB1187A for radiographic inspection of small-diameter pipe welds, the ratio D / F of the corresponding outer circle size D to the focal length F, the ratio T / D of the wall thickness T to the outer circle size D are determined according to the inner and outer circle sizes, wall thickness, effective penetration area, and focal length, and the number of penetrations N and the effective penetration length L of the corresponding pipe ring parts are obtained.

[0008] In order to better realize the present invention, further, the drilling holes of the graduated disk are divided according to the number of times N of the transillumination of the pipe ring part; and the outer diameter of the pipe ring part is equal to the inner diameter of the graduated disk.

[0009] In order to better realize the present invention, it is further applied to small-diameter pipe girth weld parts, and the outer diameter of the small-diameter pipe girth weld is ≤100mm.

[0010] In order to better realize the present invention, further, the small-diameter pipe ring weld parts have two welds with an outer diameter of 500mm, an outer diameter of 95mm, an inner diameter of 85mm, a wall thickness of 10mm, and a focal length of 1200mm.

[0011] In order to better implement the present invention, the following steps are further included: Step T1: According to the radiographic inspection standard GJB1187A, firstly, the effective irradiation area is calculated to be 600 mm, the ratio of the outer diameter D to the actual focal length F is 0.086, and the ratio of the wall thickness T to the outer diameter D is 0.105; the irradiation area required for the small-diameter pipe ring weld parts needs to be placed within the effective area of ​​600 mm; the standard shows that the number of irradiations is 7, and the effective irradiation length L is calculated to be 43 mm; Step T2: Then, make a graduated disc with an outer diameter of 95+0.5 mm, drill holes in the graduated disc and divide it into equal parts, and make a dedicated graduated circle parallel axis on the graduated disc to ensure that small-diameter pipe ring weld parts do not slide during the entire flaw detection process; Step T3: Then, the corresponding shaft is put through the middle of the adjacent arc seats to fix them; small-diameter pipe ring weld parts are placed on the two Φ100 arc seats; Step T4: Make a Φ80mm film detection system tooling and arrange lead sheets at the corresponding positions of the welds; by rotating the dividing disk and replacing the film on the film detection system tooling, realize the 0° film source external single-wall radiographic detection of the girth welds of small-diameter pipe girth weld parts.

[0012] The beneficial effects of the present invention are as follows: (1) The present invention has the advantages of accurate and reliable positioning, simple structure, and convenient installation and disassembly. It is generally applicable to the radiation detection of film-type sources of various sizes, lengths, and different single-wall transillumination. It does not need to consider tooling separately. It has strong versatility and can quickly and correctly position and fix the film, reducing the labor intensity and the requirements for the technical level of workers. It solves the problems of film-type source single-wall transillumination radiation detection requiring manual marking, manual plugging of the film, unclear transillumination, and low sensitivity. The present invention overcomes the problems of long workpiece detection time, large workload, low efficiency, and extremely poor stability in existing detection.

[0013] (2) The present invention has the advantages of simple structure, convenient installation and disassembly, and strong versatility. The present invention adopts two arc-shaped seats that are fixedly connected to the bottom plate and distributed along the length direction and connected together with two fixed shafts to prevent the parts from sliding. Then the parts are placed on the base, and then the dividing disk is placed on the parts, and the area corresponding to the parallel axes of the two dividing circles is used as the area to be observed for a single exposure. Then, a film detection system tooling (similar film detection system tooling can be designed and manufactured according to one weld or multiple welds) is used to place lead foil (to prevent scattered rays) in the area to be exposed. By rotating the parts, the film detection system tooling and the rotating disk on the dividing disk, 360° film-type source single-wall external transillumination of small-diameter parts can be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the three-dimensional cross-sectional structure of the detection tooling of the present invention; Figure 2 It is a schematic diagram of the detection state of the present invention; Figure 3 It is a schematic diagram of the structure of the parts; Figure 4 This is a schematic diagram of the position structure of the dividing disk, film and film detection system tooling.

[0015] Among them: 1-arc seat, 2-fixed shaft, 3-small diameter pipe ring weld parts, 4-dividing disk, 5-dividing circle parallel axis, 6-film detection system tooling, 7-lead sheet, 8-film, 9-weld. DETAILED DESCRIPTION

[0016] Embodiment 1: A weld detection method for pipe ring parts based on vertical illumination of single wall and single shadow by a source outside, such as Figure 1-Figure 4 As shown, the following steps are included: (1) First, according to the requirements and grade requirements of the standards such as GJB1187A for radiographic inspection of small-diameter pipe welds, and based on the inner and outer circle dimensions, wall thickness, effective penetration area, focal length, etc., the corresponding ratio D / F of the outer circle dimension D to the focal length F, and the ratio T / D of the wall thickness T to the outer circle dimension D are determined, and the number of penetrations N and the effective penetration length L of the corresponding small-diameter pipe girth weld parts 3 are obtained, and correspond to the hole pitch of the dividing disk 4. The calculation method here is the existing technology, so it will not be repeated.

[0017] (2) Then, place the small-diameter pipe girth weld parts 3 in the effective transillumination area, place the small-diameter pipe girth weld parts 3 on the arc-shaped seat 1 of equal arc, and then fix the small-diameter pipe girth weld parts 3 with the indexing disk 4, install the positioning pins and mark them in equal parts. Then, use the film detection system fixture 6 to correspond to the corresponding transillumination length, and rotate the film detection system fixture 6 and the rotating disk on the indexing disk 4 to realize the 360° film-type source external single-wall transillumination of the small-diameter pipe girth weld parts 3.

[0018] Specifically, for small-diameter pipe girth weld parts 3, two welds 9 with a length of 500mm, an outer diameter of 95mm, an inner diameter of 85mm, a wall thickness of 10mm, and a focal length of 1200mm, there are two girth welds 9, and 100% inspection of the girth welds 9 is required, using a single-wall radiographic inspection with the source outside. The specific steps are as follows: According to the relevant X-ray detection standard GJB1187A, the effective irradiation area is first calculated to be 600mm. The required irradiation area of ​​small-diameter pipe ring weld parts 3 needs to be placed within this 600mm effective area. The ratio (D / F) of the outer circle size D to the actual focal length F (1200-85) is about 0.086, and the ratio T / D of the wall thickness T to the outer circle size D is about 0.105. The number of irradiations obtained from the standard is 7 times, and the calculated effective irradiation length L is about 43mm.

[0019] Then, a dividing disk 4 with an outer diameter of 95+0.5 mm is made, the dividing disk 4 is drilled and divided into 7 equal parts, and a special dividing circle parallel axis 5 is made on the dividing disk 4 to ensure that the small-diameter pipe ring weld parts 3 do not slide during the entire flaw detection process.

[0020] Then, the corresponding shaft is put through the middle of the adjacent arc seats 1 to fix it; the small-diameter pipe ring weld parts 3 are placed on the two Φ100 arc seats 1. A Φ80mm film detection system tooling 6 is made, and lead sheets 7 (lead sheets 7 absorb scattered rays) are arranged at the corresponding position of the weld 9; by rotating the indexing disk 4 and replacing the film 8 on the film detection system tooling 6, the 360° film source is used to perform external single-wall radiographic detection of the ring weld 9 of the small-diameter pipe ring weld parts 3.

[0021] Preferably, if Figure 1-Figure 4As shown, the detection tooling used includes a transmission mechanism, a base, a dividing disc 4, a dividing circle parallel axis 5 and a film detection system tooling 6; the top of the base is provided with an arc receiving groove corresponding to the small-diameter tube ring weld parts 3, and the transmission mechanism is used to rotate the small-diameter tube ring weld parts 3; the outer side of the end of the small-diameter tube ring weld parts 3 is sleeved with a dividing disc 4, and a turntable is rotatably provided on one side of the dividing disc 4, and two dividing circle parallel axes 5 parallel to the small-diameter tube ring weld parts 3 are installed on the circumferential side of the turntable, and the area between the two adjacent dividing circle parallel axes 5 is the area for single exposure observation; the film detection system tooling 6 is inserted into the small-diameter tube ring weld parts 3 in parallel, and the film detection system tooling 6 inside the small-diameter tube ring weld parts 3 is provided with lead sheet 7 corresponding to the weld 9, and one end of the film detection system tooling 6 is provided with a rotating mechanism.

[0022] Preferably, the dividing disc 4 includes an annular seat body and a turntable, the annular seat body is sleeved on the outside of the small-diameter pipe ring weld-type parts 3, a turntable is rotatably arranged on one side of the annular seat body, and a plug-in hole is arranged on one side of the turntable along the circumferential side corresponding to the dividing circle parallel axis 5.

[0023] Preferably, the base comprises two arc-shaped seats 1 arranged in parallel, and adjacent arc-shaped seats 1 are fixedly connected via a fixed shaft 2; and an arc-shaped receiving groove is arranged on the top of the arc-shaped seat 1.

[0024] Two fixed shafts 2 are connected together on two arc-shaped seats 1 distributed along the length direction to prevent the small-diameter tube ring weld parts 3 from sliding. Then the small-diameter tube ring weld parts 3 are placed on the arc-shaped fixed base, and then the calculated indexing disc 4 is placed on the small-diameter tube ring weld parts 3, and the area corresponding to the two indexing circle parallel axes 5 is the area that needs to be observed for a single exposure, and then the film detection system tooling 6 is used to place lead sheet 7 (to prevent scattered rays) in the area to be exposed, and film 8 is placed in the exposed area; by rotating the indexing disc 4 and replacing the film detection system tooling 6, the 360° film-type source is used to perform the single-wall external transillumination of the small-diameter tube ring weld parts 3.

[0025] The present invention aims at the problems of long preparation time, large workload, poor stability and low efficiency of film-based X-ray detection technology for small-diameter pipe ring weld parts, and provides a X-ray detection tool with simple structure, convenient installation and disassembly, strong versatility, accurate and reliable detection, and the tool is not affected by operation; it can solve the following problems when film-based X-ray detection is performed on one or more welds 9 of small-diameter pipes during mass production of aviation parts, such as large geometric unclearness during exposure due to double-wall and double-image, large variation in exposure thickness, edge erosion effect caused by large exposure thickness, low sensitivity, low work efficiency and inaccurate positioning caused by manual insertion of film 8 with single-wall and single-image on small-diameter pipes, etc.

[0026] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A weld detection method for pipe ring parts based on vertical illumination of a single wall and single shadow by a source outside, characterized in that: The following steps are involved: Step S1: According to the radiographic inspection standard GJB1187A, determine the number of times N of exposure and the effective exposure length L of the corresponding pipe ring parts; Step S2: placing the pipe ring component in the effective transillumination area, placing the pipe ring component on two arc-shaped seats (1) of equal arc, and then fixing the pipe ring component with a graduated disk (4), wherein the circumferential side of the graduated disk (4) is provided with two graduated circle parallel axes (5) parallel to the pipe ring component, and the area between two adjacent graduated circle parallel axes (5) is the area for single exposure observation; Step S3: Then, the film detection system tooling (6) is used to correspond to the corresponding exposure length L, and the film detection system tooling (6) is inserted into the interior of the pipe ring part in parallel, and a lead sheet (7) is arranged at the corresponding weld (9) of the film detection system tooling (6) inside the pipe ring part; by rotating the film detection system tooling (6) and the rotating disk on the indexing disk (4), a 360° film-type source external single-wall exposure radiation detection of the pipe ring part is realized.

2. The weld detection method for pipe ring parts based on external vertical illumination of single wall and single shadow according to claim 1 is characterized in that: In the step S1, according to the requirements and grade requirements of the standard GJB1187A and other standards related to radiographic inspection of small-diameter pipe welds (9), based on the inner and outer circle dimensions, wall thickness, effective penetration area, and focal length, the corresponding ratio D / F of the outer circle dimension D to the focal length F, and the ratio T / D of the wall thickness T to the outer circle dimension D are determined, and the number of penetrations N and the effective penetration length L of one time of the corresponding pipe ring part are obtained.

3. The weld detection method for pipe ring parts based on external vertical illumination of single wall and single shadow according to claim 1 is characterized in that: The holes of the graduated disk (4) are divided according to the number of times N of transillumination of the pipe ring part; and the outer diameter of the pipe ring part is equal to the inner diameter of the graduated disk (4).

4. The weld detection method for pipe ring parts based on external vertical illumination of single wall and single shadow according to any one of claims 1 to 3, characterized in that: Applicable to small diameter pipe girth weld parts (3), the outer diameter of the small diameter pipe girth weld (9) is ≤100mm.

5. The weld detection method for pipe ring parts based on external vertical illumination of single wall and single shadow according to claim 4 is characterized in that: The small-diameter pipe ring weld part (3) has two welds (9) with an outer diameter of 500 mm, an outer diameter of 95 mm, an inner diameter of 85 mm, a wall thickness of 10 mm, and a focal length of 1200 mm.

6. The weld detection method for pipe ring parts based on external vertical illumination of single wall and single shadow according to claim 5 is characterized in that: The following steps are involved: Step T1: According to the radiographic inspection standard GJB1187A, firstly, the effective irradiation area is calculated to be 600 mm, the ratio D / F of the outer diameter dimension D to the actual focal length F is 0.086, and the ratio T / D of the wall thickness T to the outer diameter dimension D is 0.105; the irradiation area required for the small-diameter pipe ring weld part (3) needs to be placed within the effective area of ​​600 mm; the standard shows that the number of irradiations is 7, and the effective irradiation length L is calculated to be 43 mm; Step T2: Then, a graduated disk (4) with an outer diameter of 95+0.5 mm is manufactured, holes are drilled in the graduated disk (4) and the graduated disk (4) is divided into equal parts, and a dedicated graduated circle parallel axis (5) is manufactured on the graduated disk (4) to ensure that the small-diameter pipe ring weld parts (3) do not slide during the entire flaw detection process; Step T3: Then, the corresponding shaft is inserted into the middle of the adjacent arc-shaped seats (1) to fix them; the small-diameter pipe ring weld parts (3) are placed on the two Φ100 arc-shaped seats (1); Step T4: a Φ80 mm film detection system tooling (6) is manufactured, and lead sheets (7) are arranged at positions corresponding to the welds (9); by rotating the indexing disk (4) and replacing the film (8) on the film detection system tooling (6), a 360° film-type source external single-wall radiographic detection of the circumferential welds (9) of small-diameter pipe circumferential weld parts (3) is achieved.

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