CN212008367U - Radiographic inspection sensitivity sample for welding seam of heat exchange tube and tube plate - Google Patents

Abstract

The utility model discloses a heat exchange tube and tube sheet welding seam ray transillumination inspection sensitivity sample. The sample comprises a forging (1) with the same structure as a pipe plate to be detected and a heat exchange pipe (2) with the same structure as the heat exchange pipe to be detected; the heat exchange tube (2) is connected with the forge piece (1) through expansion joint and seal welding, small holes of four different types are formed in the sample, and the small holes of the four different types are respectively an inclined hole (31), a central hole (32), a parallel hole (33) and a weld toe hole (34). The utility model provides a ray transillumination inspection sensitivity sample can ensure that ray transillumination technology can cover and wait to examine all on examining the test welding seam and examine the region, can not appear leaking the leak hunting and appraising region.

Description

Radiographic inspection sensitivity sample for welding seam of heat exchange tube and tube plate

Technical Field

The utility model relates to a ray transillumination inspection field, concretely relates to steam generator heat exchange tube and tube sheet welding seam ray transillumination inspection sensitivity sample.

Background

The heat exchange tube of the steam generator is connected with the tube plate by adopting expansion joint and welding methods, so that the effects of sealing and resisting pull-off are achieved. The quality of the welding seam of the heat exchange tube and the tube plate on the steam generator directly influences the quality of the steam generator, and even directly determines the safety performance of the whole steam generator, so that radiographic inspection, penetrant inspection, helium leakage detection and the like are needed to be performed on the welding seam after welding is completed, the quality of the welding seam is checked, and the welding seam is ensured not to be leaked.

When the radiographic inspection is carried out on the welding seam of the heat exchange tube and the tube plate of the steam generator, a radiographic inspection sensitivity sample is often required to be used for inspecting whether all areas to be inspected on the welding seam to be inspected (namely the welding seam of the heat exchange tube and the tube plate of the steam generator) can be covered by 100% or not so as to avoid missing inspection.

The welding defects of the welding seams of the heat exchange tube and the tube plate are mainly and intensively distributed on the welding seams and the welding heat affected zone. However, the conventional radiographic inspection sensitivity test sample generally only has artificial defects on the weld joint, and the radiographic inspection process cannot be ensured to cover the welding heat affected zone.

Therefore, it is highly desirable to develop a radiology inspection process and a novel radiology inspection sensitivity sample to ensure that all welding defects in the to-be-inspected region on the weld joint between the heat exchange tube of the steam generator and the tube plate can be inspected.

SUMMERY OF THE UTILITY MODEL

In order to overcome the problems, the inventor of the invention carries out intensive research and designs a test sample for testing the sensitivity of the heat exchange tube and the tube plate welding seam by ray transillumination so as to ensure that the ray transillumination process can cover all areas to be tested on the welding seam to be tested. Wherein, this ray transillumination inspection sensitivity sample is formed through expanded joint and seal welding by heat exchange tube and forging, has seted up inclined hole, centre bore, parallel hole and welding toe hole on this sample, inspects the sensitivity of heat exchange tube pipe wall heat affected area department and weld toe department tube sheet heat affected area department under the welding seam circular arc department, welding seam and the heat exchange tube fusion department, the welding seam of inspection welding seam with these apertures respectively inspection ray transillumination inspection technology, thereby has accomplished the utility model discloses a sensitivity of welding toe department tube sheet heat affected area department is examined to the welding seam.

Specifically, the utility model aims to provide a ray transillumination inspection sensitivity sample, the sample includes forging 1 the same with the pipe plate structure of examining and heat exchange tube 2 the same with the heat exchange tube of examining, connect through expanded joint and seal welding between heat exchange tube 2 and forging 1, seted up tube hole 11 on forging 1, seted up the aperture of four different grade types on the welding seam or welding heat affected zone near tube hole 11 on the sample, the aperture of four different grade types is respectively inclined hole 31, centre bore 32, parallel hole 33 and weld toe hole 34,

the inclined hole 31 is formed in the arc position of the welding seam and used for detecting the sensitivity of the ray transillumination detection process at the arc position of the welding seam to be detected;

the central hole 32 is formed at the fusion position of the welding line and the heat exchange tube and is used for detecting the sensitivity of the ray transillumination detection process at the fusion position of the welding line to be detected and the heat exchange tube;

the parallel hole 33 is arranged in a heat affected zone of the tube wall of the heat exchange tube below the welding line and is used for detecting the sensitivity of the ray transillumination detection process in the heat affected zone of the tube wall of the heat exchange tube below the welding line to be detected;

the toe holes 34 are formed in the heat affected zone of the tube sheet at the weld toes and are used for detecting the sensitivity of the radiographic inspection process in the heat affected zone of the tube sheet at the weld toes of the weld joint to be inspected.

The utility model discloses the beneficial effect who has includes:

(1) the utility model provides a ray transillumination test sensitivity sample, simple structure, easy manufacture, wide application range and good test effect;

(2) the utility model provides a ray transillumination inspection sensitivity sample, set up inclined hole, centre bore, parallel hole and weld toe hole on this sample, inspect the sensitivity of ray transillumination inspection technology at welding seam circular arc department, welding seam and heat exchange tube fusion department, heat exchange tube wall heat affected zone department under the welding seam and weld toe department tube sheet heat affected zone department respectively with these apertures, can ensure that the welding seam 100% of examining is covered, can not cause the missed examination;

(3) the utility model provides a heat exchange tube and tube sheet welding seam ray transillumination inspection technology can once only cover the whole welding seam of examining, has improved detection efficiency.

Drawings

FIG. 1a is a perspective view of a radioscopy sensitivity test sample according to a preferred embodiment of the present invention;

FIG. 1b shows a side view of a radioscopy sensitivity sample according to a preferred embodiment of the present invention;

FIG. 2 shows a layout of the weld and weld heat affected zone of a radioscopy sensitivity test sample when one end of the heat exchange tube is projected out of the forging;

FIG. 3a shows a profile of the angled holes as one end of the heat exchange tube protrudes through the forging;

FIG. 3b shows a cross-sectional view of the angled hole when one end of the heat exchange tube is protruding out of the forging;

FIG. 4a shows a profile of the central bore when one end of the heat exchange tube is extruded through the forging;

FIG. 4b shows a cross-sectional view of the central bore when one end of the heat exchange tube is extruded through the forging;

FIG. 5a shows a distribution pattern of parallel holes when one end of the heat exchange tube protrudes through the forging;

FIG. 5b shows a cross-sectional view of a parallel hole when one end of the heat exchange tube protrudes through the forging;

FIG. 6a shows a distribution pattern of the weld toe holes when one end of the heat exchange tube protrudes through the forging;

FIG. 6b shows a cross-sectional view of the weld toe hole when one end of the heat exchange tube is extruded out of the forging;

FIG. 7 shows a map of the weld and weld heat affected zone of a radiology test sensitivity sample when one end of the heat exchange tube is flush with the forging;

FIG. 8 shows a cross-sectional view of the angled hole when one end of the heat exchange tube is flush with the forging;

FIG. 9 shows a cross-sectional view of the central bore when one end of the heat exchange tube is flush with the forging;

FIG. 10 shows a cross-sectional view of a parallel hole when one end of the heat exchange tube is flush with the forging;

FIG. 11 shows a cross-sectional view of a weld toe hole when one end of the heat exchange tube is flush with the forging;

FIG. 12 shows a perspective layout according to a preferred embodiment of the present invention;

FIG. 13 is a perspective view showing the inclined hole in the first transillumination in example 1;

FIG. 14 shows a transillumination map of an inclined bore under a final defined transillumination process;

FIG. 15 shows a perspective view of the central bore under the final defined transradiographic process;

FIG. 16 shows a transillumination of parallel wells under a final defined transillumination process;

FIG. 17 shows a trans-illumination map of a vertical hole under a final defined trans-illumination process;

fig. 18 shows a perspective view of a weld in example 2.

The reference numbers illustrate:

1-forging;

11-tube hole

2-heat exchange tube;

21-pipe wall of heat exchange pipe;

22-heat exchange tube outer wall;

23-inner wall of heat exchange tube;

31-an inclined hole;

32-a central aperture;

33-parallel holes;

34-toe hole welding;

4-arc position of welding seam;

5-fusion of the welding seam and the heat exchange tube;

6-heat-affected zone of tube wall of heat exchange tube under weld joint;

7-heat affected zone of tube plate at weld toe;

8-a radiation source;

9-fixed ray source device;

10-Metal cassette

11-film;

12-a compensation block;

13-overlaying layer;

14-welding seam.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. The features and advantages of the present invention will become more apparent from the description.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

When a heat exchange tube on the steam generator is welded with a tube plate, the heat exchange tube needs to be inserted into a tube hole on the tube plate for expanded joint, and the welding is carried out after the expanded joint is completed. The condition that the heat exchange tube stretches into the tube plate comprises two conditions, wherein one end of the heat exchange tube protrudes out of the tube plate under the first condition, and the other end of the heat exchange tube stretches out of the tube plate. In the second case, one end of the heat exchange tube is flush with the tube plate, and the other end extends out of the tube plate. The utility model discloses in, with the heat exchange tube protrusion tube sheet one end or with the terminal surface definition of the one end of tube sheet parallel and level be the upper surface of tube sheet. The welding between the heat exchange tube and the tube plate is carried out on the upper surface of the tube plate.

When welding, if the gap between the heat exchange tube and the tube hole on the tube plate is relatively large, a welding material, such as a welding rod or a welding wire, can be filled between the gaps, and at this time, the welding seam between the heat exchange tube and the tube plate is composed of a deposited welding material (i.e., deposited metal) and a partially melted base material (the heat exchange tube and the tube plate). If the gap between the heat exchange tube and the tube hole on the tube plate is smaller, the welding can be directly carried out without filling welding flux, and the welding seam at the moment is composed of molten base materials, namely the tube plate and the heat exchange tube are fused.

The welding defect distribution area of the welding seam of the heat exchange tube and the tube plate comprises the welding seam and a welding heat influence area. The welding heat affected zone refers to a zone where the solid base metal on both sides of the welding seam undergoes obvious structural and performance changes under the action of welding heat circulation.

When the sensitivity inspection of the radiographic process is carried out, artificial defects are generally arranged at the same positions of a radiographic inspection sensitivity sample according to the positions where the defects are likely to appear when the heat exchange tube and the tube plate are welded. If the adopted ray transillumination process can be used for detecting all artificial defects on the sample with the ray transillumination detection sensitivity, the ray transillumination process can meet the technical requirements of the welding line to be detected. However, the conventional radiographic inspection sensitivity sample has a single position for manually setting defects, and cannot meet the requirements of actual operation.

In order to ensure that all on steam generator heat exchange tube and the tube sheet welding seam wait that the welding defect homoenergetic that waits to examine the region can be examined out, the utility model provides an aspect provides a ray transillumination inspection sensitivity sample, the sample include with wait to examine the forging 1 that the tube sheet structure is the same and with wait to examine the heat exchange tube 2 that the heat exchange tube is the same.

The forging 1 is made of the same or similar material to the tube plate to be detected, is selected from a ferrite forging or a nickel-based forging, and is preferably a ferrite forging.

The thickness of forging 1 is more than or equal to 15mm, preferably more than or equal to 35mm, more preferably more than or equal to 50mm, the thickness of forging 1 is less than or equal to the thickness of the pipe plate to be inspected.

The material of heat exchange tube 2 is the same with the material of waiting to examine the heat exchange tube, the specification of heat exchange tube 2 is also the same with the specification of waiting to examine the heat exchange tube.

In a preferred embodiment, the forging 1 and the heat exchange tube 2 are connected by expansion welding and seal welding.

In the radiographic inspection sensitivity sample, the forging 1 is used for replacing a tube plate to be inspected, and the expansion joint process and the seal welding process adopted between the forging 1 and the heat exchange tube 2 are the same as those adopted between the tube plate to be inspected and the heat exchange tube.

In a preferred embodiment, the coupon further comprises a weld overlay.

In order to adapt to different working environments, a surfacing layer is required to be overlaid on the tube plate of some steam generators, and when the surfacing layer is overlaid on the tube plate to be inspected, the same surfacing layer should be also arranged on the forging piece 1. Wherein, the same overlaying layers mean that the overlaying process is the same, the overlaying materials are the same and the overlaying thickness is the same.

In a preferred embodiment, pipe holes 11 are formed in the forged piece 1, the pipe holes 11 are through holes, and the arrangement form of the pipe holes 11 is consistent with that of the pipe holes on the pipe plate to be inspected.

The tube holes 11 are arranged in at least two rows on the forging 1, at least four tube holes 11 are formed in each row, and the hole distance of the tube holes 11 and the diameter of the tube holes 11 are consistent with those of the tube holes on the tube plate to be tested.

The utility model discloses in, tube hole 11 arranges two rows at least on forging 1, and expanded joint and sealed welding have heat exchange tube 2 in one row of tube hole wherein, and another row of tube hole is used for fixed metal magazine.

The pipe hole 11 corresponds to a through hole on the metal cassette, and the forging 1 and the metal cassette can be connected together by using the expansion plug.

In a preferred embodiment, four different types of small holes are formed in the weld seam or weld heat affected zone near the pipe hole 11 on the test specimen, the four different types of small holes are an inclined hole 31, a central hole 32, a parallel hole 33 and a weld toe hole 34, wherein each type of small hole is formed in the weld seam or weld heat affected zone near the same pipe hole 11. The positions of the welding seam and the welding heat influence area of the forge piece 1 and the heat exchange tube 2 on the ray transillumination detection sensitivity sample are the same as the positions of the welding seam and the welding heat influence area on the tube plate to be detected and the heat exchange tube. The utility model discloses in, use ray perspective inspection sensitivity sample as the example, explain welding seam and welding heat affected zone.

The utility model discloses in, the condition that heat exchange tube 2 stretched into forging 1 includes two kinds, and under the first condition, heat exchange tube 2's one end protrusion forging 1, the other end stretches out forging 1. In the second case, one end of the heat exchange tube 2 is flush with the forged piece 1, and the other end extends out of the tube plate. The utility model discloses in, with the heat exchange tube 2 protrusion forging 1 one end or with the terminal surface definition of the one end of 1 parallel and level of forging for the upper surface of forging 1. And performing expansion joint and sealing welding on the forging 1 and the heat exchange tube 2 on the upper surface of the forging 1.

The welding seam of the forging 1 and the heat exchange tube 2 on the sensitivity sample for radiographic inspection comprises a welding seam arc part 4 and a welding seam and heat exchange tube fusion part 5. When one end of the heat exchange tube 2 protrudes out of the forging 1, the welding seam arc 4 refers to an arc-shaped bulge similar to a chamfer formed by a welding seam between the upper surface of the forging 1 and the outer surface of the heat exchange tube 2. The weld-to-heat exchange tube fusion 5 refers to the area near the intersection of the weld and the heat exchange tube, as shown in fig. 2. When one end of the heat exchange tube 2 is flush with the forged piece 1, the welding seam arc part 4 refers to an arc-shaped bulge formed by welding seams between the upper surface of the forged piece 1 and the upper surface and the inner wall of the heat exchange tube 2. The weld-tube fusion 5 refers to the weld area above the interface of the heat exchange tube 2 and the forging 1, as shown in fig. 7.

The welding heat affected zone on the test sample of the radiographic inspection sensitivity comprises a heat exchange tube wall heat affected zone 6 under the welding seam and a tube plate heat affected zone 7 at the welding toe. The utility model discloses in, when the one end protrusion forging 1 of heat exchange tube 2, heat exchange tube pipe wall heat affected zone 6 indicates the heat exchange tube pipe wall region within 0-8mm under the interface of distance welding seam and 1 upper surface of forging. The weld toe tube plate heat affected zone 7 refers to the area of the forging 1 which is 0-8mm away from the junction of the weld surface and the upper surface of the forging 1 in the horizontal direction and is within 0-8mm away from the upper surface of the forging 1 in the vertical direction, and is shown in FIG. 2. When one end of the heat exchange tube 2 is flush with the forged piece 1, the heat exchange tube wall heat affected zone 6 below the weld joint refers to the heat exchange tube wall area within the range of 0-8mm away from the junction of the weld joint surface and the inner wall of the heat exchange tube 2. The weld toe tube sheet heat affected zone 7 refers to the area of the forging 1 within 0-8mm from the interface of the weld surface and the upper surface of the forging 1 in the horizontal direction and within 0-8mm from the upper surface of the forging 1 in the vertical direction, as shown in fig. 7.

When one end of the heat exchange tube 2 protrudes out of the forged piece 1, the small holes of four different types formed in the welding line or the welding heat affected zone near the tube hole 11 are the same as the small holes of four different types formed in the welding line or the welding heat affected zone near the tube hole 11 when one end of the heat exchange tube 2 is flush with the forged piece 1.

In a preferred embodiment, at least four of each type of apertures are provided in the weld or weld heat affected zone adjacent the same pipe bore 11, evenly distributed as shown in fig. 3a, 4a, 5a and 6 a.

The utility model discloses in, heat exchange tube 2 is the girth weld with the welding seam of forging 1, preferably, along the girth weld, at every interval 90, offers a aperture. This is because, when carrying out the X-ray transillumination inspection, the ray source is placed in heat exchange tube 2, adopts the mode of back transmission to transilluminate, and 90 arrange can ensure that once transmission can cover whole heat exchange tube at interval, avoids appearing missing the detection in the circumferencial direction.

In a preferred embodiment, the inclined holes 31 are cylindrical, and the diameter of the inclined holes 31 is 0.3 to 0.9mm, preferably 0.4 to 0.6mm, and more preferably 0.5 mm; the length of the inclined hole 31 is 0.3 to 0.9mm, preferably 0.4 to 0.6mm, and more preferably 0.5 mm.

The inclined hole 31 is formed in the arc position of the welding line and used for detecting the sensitivity of the ray transillumination detection process at the arc position of the welding line to be detected.

When one end of the heat exchange tube 2 protrudes out of the forging 1, the inclined hole 31 is formed by the following method: in the middle of the arc-shaped projection of the weld, a hole is punched obliquely downwards from the weld surface in the direction towards the heat exchange tube 2, as shown in fig. 3 b. Wherein, a certain included angle is formed between the central axis of the inclined hole 31 and the upper surface of the forging 1, and the included angle is preferably 10-80 degrees, preferably 30-60 degrees, and more preferably 45 degrees. When one end of the heat exchange tube 2 is flush with the forged piece 1, the inclined hole 31 is formed by the following method: at the highest position of the arc-shaped bulge of the welding seam, a hole is drilled obliquely downwards from the surface of the welding seam in the direction towards the forged piece 1, as shown in fig. 8. Wherein, a certain included angle is formed between the central axis of the inclined hole 31 and the upper surface of the forging 1, and the included angle is preferably 10-80 degrees, preferably 30-60 degrees, and more preferably 45 degrees.

The central hole 32 is cylindrical, and the diameter of the central hole 32 is 0.3-0.9mm, preferably 0.4-0.6mm, and more preferably 0.5 mm; the length of the central bore 32 is 0.3-0.9mm, preferably 0.4-0.6mm, more preferably 0.5 mm.

The central hole 32 is formed at the fusion position of the welding line and the heat exchange tube and is used for detecting the sensitivity of the ray transillumination detection process at the fusion position of the welding line and the heat exchange tube of the welding line to be detected.

When one end of the heat exchange tube 2 protrudes out of the forging 1, the method for forming the central hole 32 comprises the following steps: and (3) drilling downwards at the junction of the welding line and the heat exchange tube 2 along the direction vertical to the upper surface of the forging 1. Wherein the outer wall surface of the central hole 32 is inwardly contracted from the outer wall 22 of the heat exchange tube to the tube wall 21 of the heat exchange tube by 0.01-0.05mm, preferably 0.01-0.04mm, more preferably 0.04mm, as shown in fig. 4 b. Wherein, the length L between two arrows in fig. 4b is the length of the inner wall surface of the central hole 32 from the outer wall 22 of the heat exchange tube to the tube wall 21 of the heat exchange tube.

When one end of the heat exchange tube 2 is flush with the forged piece 1, the method for forming the central hole 32 comprises the following steps: the inner wall 23 of the heat exchange tube 2 is taken as a reference, a distance which is the same as the thickness of the tube wall 21 of the heat exchange tube is measured on the surface of the welding seam, and then holes are punched downwards at the position along the direction vertical to the upper surface of the forging 1, as shown in figure 9.

The parallel holes 33 are cylindrical, and the diameter of the parallel holes 33 is 0.3-0.9mm, preferably 0.4-0.6mm, and more preferably 0.5 mm; the length of the parallel holes 33 is 0.3 to 0.9mm, preferably 0.4 to 0.6mm, more preferably 0.5 mm.

The parallel hole 33 is arranged in a heat affected zone of the tube wall of the heat exchange tube under the welding seam and is used for detecting the sensitivity of the ray transillumination detection process in the heat affected zone of the tube wall of the heat exchange tube under the welding seam of the welding seam to be detected.

When one end of the heat exchange tube 2 protrudes out of the forging 1, the method for forming the parallel holes 33 is as follows: holes are punched in the inner wall 23 of the heat exchange tube below the upper surface of the forging 1 in a direction perpendicular to the tube wall 21 of the heat exchange tube, wherein the central axes of the parallel holes 33 are parallel to the upper surface of the forging 1 and are 1-8mm, preferably 2-6mm, and more preferably 3mm from the upper surface of the forging 1, as shown in fig. 5 b.

When one end of the heat exchange tube 2 is flush with the forged piece 1, the method for forming the parallel holes 33 is as follows: holes are punched in the inner wall 23 of the heat exchange tube in the direction perpendicular to the tube wall 21 of the heat exchange tube below the junction of the weld surface and the inner wall 23 of the heat exchange tube, wherein the central axis of the parallel holes 33 is parallel to the upper surface of the forging 1 and is 3-15mm, preferably 5-8mm, and more preferably 5mm from the upper surface of the forging 1, as shown in fig. 10.

The toe welding holes 34 are cylindrical, and the diameter of the toe welding holes 34 is 0.3-0.9mm, preferably 0.4-0.6mm, and more preferably 0.5 mm; the length of the toe holes 34 is 0.3-0.9mm, preferably 0.4-0.6mm, more preferably 0.5 mm.

The toe holes 34 are formed in the heat affected zone of the tube sheet at the weld toes and are used for detecting the sensitivity of the radiographic inspection process in the heat affected zone of the tube sheet at the weld toes of the weld joint to be inspected.

When one end of the heat exchange tube 2 protrudes out of the forging 1, the method for forming the toe welding holes 34 is as follows: holes are punched in a direction perpendicular to the forging 1 at the intersection of the weld surface and the upper surface of the forging 1 (i.e., at the weld toes), wherein the hole edges of the weld toe holes 34 are circumscribed by the weld toes, as shown in FIG. 6 b.

When one end of the heat exchange tube 2 is flush with the forged piece 1, the method for forming the toe welding holes 34 comprises the following steps: holes are punched in a direction perpendicular to the forging 1 at the intersection of the weld surface and the upper surface of the forging 1 (i.e., at the weld toes), wherein the hole edges of the weld toe holes 34 are circumscribed by the weld toes, as shown in fig. 11.

The utility model discloses another aspect provides a heat exchange tube and tube sheet welding seam ray transillumination inspection technology, technology includes following step:

step 1, selecting a ray transillumination test sensitivity sample according to a welding line to be tested;

specifically, according to the materials of the heat exchange tube and the tube plate in the weld joint of the heat exchange tube and the tube plate to be detected, the welding process of the heat exchange tube and the tube plate, the arrangement of tube holes on the tube plate, the diameter of the tube holes, the distance between the tube holes and the presence or absence of a surfacing layer on the tube plate, the ray transillumination detection sensitivity samples with the same condition are selected.

Step 2, installing a ray transillumination inspection device on a ray transillumination inspection sensitivity sample;

in a preferred embodiment, the radiographic inspection device comprises a radiation source 8, a fixed radiation source device 9, a metal cassette 10, a film 11, an intensifying screen and a compensating block 12, as shown in fig. 12, wherein 13 in fig. 12 represents a surfacing layer, and 14 represents a welding seam. Wherein the intensifying screen is arranged between the metal cassette 10 and the film 11, which is not marked in the figure.

Wherein the radiation source is selected from an X-ray source or a gamma-ray source, preferably a gamma-ray source, such as an Ir-192 radiation source or an Se-75 radiation source. The fixed ray source device is used for fixing the ray source and adjusting the position of the ray source to a welding seam in the inspection process.

The intensifying screen is attached to two sides of the film, the metal cassette comprises two metal plates, and the film is placed in the metal cassette, namely between the two metal plates. The utility model discloses in, do not do special regulation to the quantity of film, film quantity can be one, also can be two, when carrying out the transillumination inspection, can select according to actual conditions. The film is preferably kodak M100 or AGFA film model D3.

The metal cassette is placed on the upper surface of a test sample for radiographic inspection sensitivity. Wherein, the upper surface of the sensitivity sample of the ray transillumination inspection is also the upper surface of the forging 1.

Through holes are formed in the metal cassette and the film, and the through holes are the same as the pipe holes 11 in the forging piece 1 in the radiographic inspection sensitivity sample. The same means that the size, the number, the spacing and the arrangement of the through holes on the metal cartridge and the film are the same as those of the pipe holes 11 on the forging 1.

Wherein, a row of through holes on the metal cassette and the film correspond to the pipe hole 11 connected with the heat exchange pipe 2 on the forging 1, and the metal cassette and the film are used for extending the radioactive source into the heat exchange pipe 2 for transillumination. The other row of through holes on the metal cassette and the film correspond to the pipe hole 11 for fixing the metal cassette on the forging 1 and are used for fixing the metal cassette on the upper surface of the radiographic inspection sensitivity sample.

The compensation block is fixed on the metal cassette and used for compensating the thickness difference between the forge piece 1 and the welding line. Because the welding seam has certain thickness, consequently there is the thickness difference between the upper surface of forging 1 and the welding seam, can lead to the blackness difference on the film after transillumination. The compensation block is arranged for compensating the thickness between the forging 1 and the welding line, so that the thickness of metal through which rays pass can be ensured to be the same, and the blackness difference on the bottom plate after transillumination is avoided.

Step 3, setting technological parameters of radiographic inspection, and performing radiographic inspection;

in a preferred embodiment, the process parameters include exposure time, radioactivity of the radiation source, focal length and focal spot size.

In the present invention, the exposure time is 20s-8min, preferably 40s-5min, and more preferably 50 s.

In the present invention, the radioactivity of the radioactive source is 0.5-2.5Ci, preferably 1-2Ci, and more preferably 1.5 Ci.

In the present invention, the focal length is 8-28mm, preferably 12-22mm, and more preferably 18 mm.

In the present invention, the focal size Φ is 0.2-0.8mm, preferably 0.3-0.6mm, and more preferably 0.5 mm.

In addition to this, the type of film, and the presence or absence of the compensation block, also has an effect on the transillumination result. In the present invention, the film is preferably an AGFA film D3 model or a kodak film M100 model, and more preferably a kodak film M100 model.

In a preferred embodiment, after setting a set of parameters, transillumination is performed for each type of small hole in the order of the inclined hole 31, the central hole 32, the parallel hole 33 and the perpendicular hole 34. During transillumination, if one type of small hole is not visible in the transillumination film, the process parameters are changed again, and then the transillumination operation is repeated for the four types of small holes.

Step 4, developing the film, and analyzing the test result;

after the transillumination is finished, the film is washed, and the technological parameters are adjusted according to the transillumination result until the four types of small holes are clearly visible in the negative film, so that the adopted ray transillumination inspection technology can cover the whole range to be detected of the welding line to be inspected, and the phenomenon of missed inspection cannot occur.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

Example 1

And (3) detecting the sensitivity of the ray transillumination detection process of the welding seam of the heat exchange tube and the tube plate of the Hualong I steam generator on a ray transillumination detection sensitivity sample.

One end of a heat exchange tube 2 in the radiographic inspection sensitivity sample protrudes out of a forging 1, wherein the forging 1 is made of ferrite steel forging with the material brand of 18MND 5. And a nickel-based surfacing layer with the thickness of 8mm is overlaid on the forging 1. Two rows of pipe holes 11 are formed in the forging piece 1, and each row is provided with 4 pipe holes 11. The diameter of the tube holes 11 is 17.5mm, the hole pitch in each row is 21.6mm, and the row pitch is 12.5 mm. The material of the heat exchange tube is NC30Fe, and the wall thickness is 1.01 cm.

The heat exchange tubes 2 are connected to 4 tube holes 11 in one row, four inclined holes 31 are uniformly formed in the welding line arc of the first tube hole 11, the diameter of each inclined hole 31 is 0.5mm, the length of each inclined hole 31 is 0.5mm, and the included angle between the central axis of each inclined hole 31 and the upper surface of the forging piece 1 is 45 degrees.

Four central holes 32 are uniformly formed in the fusion part of the welding line at the second tube hole 11 and the heat exchange tube, the diameter of each central hole 32 is 0.5mm, the length of each central hole is 0.5mm, and the outer wall surface of each central hole 32 is inwards contracted by 0.04mm from the outer wall surface of the heat exchange tube to the tube wall 21 of the heat exchange tube by taking the outer wall 22 of the heat exchange tube as a reference.

Four parallel holes 33 are uniformly formed in the heat-affected zone of the tube wall of the heat exchange tube under the welding seam of the third tube hole 11, the diameter of each parallel hole 33 is 0.5mm, the length of each parallel hole 33 is 0.5mm, and the distance between the central axis of each parallel hole 33 and the upper surface of the forging piece 1 is 3 mm.

Four weld toe holes 34 are uniformly formed in the heat affected zone of the tube plate at the weld toe position of the fourth tube hole 11, the diameter of each weld toe hole 34 is 0.5mm, the length of each weld toe hole is 0.5mm, and the hole edge of each weld toe hole 34 is circumscribed with the weld toe.

The radiographic inspection device adopted by the embodiment comprises a ray source, a fixed ray source device, a metal cassette, a film, an intensifying screen and a compensating block. Wherein, the metal cassette comprises a stainless steel front plate and a stainless steel back lining plate; the intensifying screen is a lead metal intensifying screen and comprises 1 front screen with the thickness of 0.02mm and 1 rear screen with the thickness of 0.02 mm; the compensation block is a steel compensation block.

The welding seam ray transillumination inspection comprises the following specific processes:

1) installing the model D3 of the AGFA film and the intensifying screen in the metal cassette according to the sequence of the stainless steel front plate of the metal cassette, the intensifying screen front screen, the film, the intensifying screen rear screen and the stainless steel back lining plate of the metal cassette;

2) fixing a metal cassette on a ray transillumination detection sensitivity sample, and placing an Ir-192 ray source into a heat exchange tube 2 through the metal cassette;

3) transillumination is carried out in a central exposure mode with a radiation source inside, the exposure time is set to be 2 minutes, the radioactivity of the radiation source is set to be 0.75Ci, the focal size is set to be phi 0.5mm, and the focal length is set to be 25 mm;

4) after exposure is finished, the ray source is withdrawn;

5) taking out the exposed radiographic film, and carrying out film darkroom treatment by adopting developing solution and fixing solution, wherein the temperature of the liquid medicine is 28 ℃, and the washing time is 5 minutes;

6) after washing, the ray negative is subjected to a blackness test.

7) Evaluating the ray negative;

8) and determining whether a compensation block is added or not according to the transillumination result, adjusting the type of the film, the exposure time of the radioactive source, the radioactivity, the focal size and the focal length, and repeating the previous transillumination operation until the four types of small holes in the sensitivity sample of the radiographic inspection can be seen in the negative film.

And (3) weld ray transillumination inspection results and rating:

under the transillumination condition, the tube hole provided with the inclined hole is transilluminated, the measured film blackness range is 3.0-5.5, and the requirement of the standard on the blackness is not met, wherein the measured film blackness range is 2.7-4.5. The transillumination result of the first transillumination is shown in fig. 13, and the presence of the inclined holes is not observed in fig. 13. Therefore, the process condition can not meet the requirement of weld joint detection.

Under the condition that the finally determined radiographic transillumination process (the film is a Kodak film M100 model, a compensation block is added, the exposure time is 50 seconds, the radioactivity of a radioactive source is set to be 1.5Ci, the focal size is set to be phi 0.5mm, and the focal length is set to be 18mm, namely the finally determined radiographic transillumination process), four types of small holes in a radiographic inspection sensitivity sample are visible in the film, and the transillumination inspection results are shown in table 1:

TABLE 1 radiology sensitivity test results

Transillumination of this transillumination test is shown in fig. 14-18, where fig. 14 is a transillumination of the angled holes, and the presence of four angled holes is clearly seen in fig. 14. Fig. 15 is a perspective view of parallel holes, and the presence of four central holes can be clearly seen in fig. 15. Fig. 16 is a perspective view of parallel holes, and the presence of four parallel holes can be clearly seen in fig. 16. Fig. 17 is a perspective view of a vertical hole, and the presence of four vertical holes can be clearly seen in fig. 17.

As can be seen from the transillumination results, the final transillumination process determined in this example 1 was used to transilluminate the radioscopy sensitivity sample, and the small holes at different positions in the radioscopy sensitivity sample were visible in the negative.

Therefore, the transillumination sensitivity of the final transillumination process determined in the embodiment 1 at the weld arc, the weld center, the heat-affected zone of the tube wall of the heat exchange tube under the weld and the heat-affected zone of the tube plate at the weld toe can meet the related technical requirements of the transillumination detection of the heat exchange tube of the hualong first steam generator and the weld of the tube plate.

In addition, the image position of the small hole in the inspection negative of the sensitivity sample is detected by ray transillumination, and the judgment range of the welding seam negative to be detected can be judged, so that the welding seam to be detected and the heat affected zone can be evaluated as required in negative evaluation, and a leak detection evaluation area can not be generated.

Example 2

The final radiographic inspection process determined in the embodiment 1 is adopted to transilluminate the welding seam between the heat exchange tube and the tube plate of the Hualong I steam generator, and the specific inspection process is as follows:

1) the Kodak film M100 model and the intensifying screen are arranged in a metal cassette; 2) fixing a metal cassette on a welding seam between a heat exchange tube and a tube plate of a steam generator; 3) and the Ir-192 ray source is placed in the heat exchange tube through the metal cassette; 4) transillumination is carried out in a central exposure mode with a radiation source inside, and parameter setting is carried out according to the final radiographic inspection process parameters determined in the embodiment 1; 5) after exposure is finished, the ray source is withdrawn; 6) taking out the exposed radiographic film, and carrying out film darkroom treatment by adopting developing solution and fixing solution, wherein the temperature of the liquid medicine is 28 ℃, and the washing time is 5 minutes; 7) after washing, carrying out a blackness test on the ray negative film; 8) and (5) ray negative evaluation.

The blackness test shows that the range of the blackness of the negative film is between 2.7 and 4.5, and a transillumination picture of the weld joint is shown in figure 18. As can be seen from FIG. 18, the weld joint between the heat exchange tube and the tube plate has no standard-exceeding defect.

In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "front", "rear", and the like indicate the directions or positional relationships based on the operating states of the present invention, and are only for convenience of description and simplification of the description, but do not indicate or imply that the device or element indicated must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

The present invention has been described above in connection with preferred embodiments, which are merely exemplary and illustrative. On this basis, can be right the utility model discloses carry out multiple replacement and improvement, these all fall into the utility model discloses a protection scope.

Claims (7)

1. A radioscopy test sensitivity sample, characterized by: the sample comprises a forging (1) with the same structure as the pipe plate to be detected and a heat exchange pipe (2) with the same structure as the heat exchange pipe to be detected;

the heat exchange tube (2) is connected with the forging (1) through expansion joint and seal welding,

the forged piece (1) is provided with a pipe hole (11), four small holes of different types are arranged on a welding seam or a welding heat affected zone near the pipe hole (11) on the sample, the four small holes of different types are respectively an inclined hole (31), a central hole (32), a parallel hole (33) and a weld toe hole (34),

the inclined hole (31) is formed in the arc position of the welding line and used for detecting the sensitivity of the ray transillumination detection process at the arc position of the welding line to be detected;

the central hole (32) is formed at the fusion part of the welding line and the heat exchange tube and is used for detecting the sensitivity of the ray transillumination detection process at the fusion part of the welding line to be detected and the heat exchange tube;

the parallel hole (33) is arranged in a heat affected zone of the tube wall of the heat exchange tube below the welding line and is used for detecting the sensitivity of the ray transillumination detection process in the heat affected zone of the tube wall of the heat exchange tube below the welding line of the welding line to be detected;

the toe welding hole (34) is formed in the heat affected zone of the tube plate at the toe welding position and used for detecting the sensitivity of the radiographic inspection process in the heat affected zone of the tube plate at the toe welding position of the welding joint to be detected.

2. The sensitivity sample according to claim 1, characterized in that: the pipe holes (11) are arranged in at least two rows on the forging (1), and each row is provided with at least four pipe holes (11);

a heat exchange tube (2) is welded in a row of tube holes in an expanded joint and sealing manner; the other row of pipe holes is used for fixing the metal cassette.

3. The sensitivity sample according to claim 2, characterized in that: each type of small hole is arranged on a welding seam or in a welding heat affected zone near the same pipe hole (11);

at least four small holes of each type are arranged on the welding seam or in the welding heat affected zone near the same pipe hole (11) and are uniformly distributed.

4. The sensitivity sample according to claim 3, characterized in that: the inclined hole (31) is cylindrical, and the diameter of the inclined hole (31) is 0.3-0.9 mm; the length of the inclined hole (31) is 0.3-0.9 mm;

when one end of the heat exchange tube (2) protrudes out of the forging piece (1), the inclined hole (31) is formed by punching a hole obliquely downwards from the surface of a welding seam through the arc-shaped convex middle part of the welding seam in the direction towards the heat exchange tube (2);

when one end of the heat exchange tube (2) is flush with the forged piece (1), the inclined hole (31) is formed by obliquely punching a hole downwards from the surface of the welding seam in the direction towards the forged piece (1) at the highest position of the arc-shaped bulge of the welding seam.

5. The sensitivity sample according to claim 3, characterized in that: the central hole (32) is cylindrical, and the diameter of the central hole (32) is 0.3-0.9 mm; the length of the central hole (32) is 0.3-0.9 mm;

when one end of the heat exchange tube (2) protrudes out of the forging piece (1), the central hole (32) is punched downwards at the junction of the welding line and the heat exchange tube (2) along the direction vertical to the upper surface of the forging piece (1), and the outer wall surface of the central hole (32) is obtained by inwards shrinking 0.01-0.05mm from the outer wall (22) of the heat exchange tube to the wall (21) of the heat exchange tube;

when one end of the heat exchange tube (2) is flush with the forged piece (1), the central hole (32) is obtained by measuring a distance which is the same as the thickness of the tube wall (21) of the heat exchange tube on the surface of a welding seam by taking the inner wall (23) of the heat exchange tube (2) as a reference and then punching downwards at the position along the direction vertical to the upper surface of the forged piece (1).

6. The sensitivity sample according to claim 3, characterized in that: the parallel holes (33) are cylindrical, and the diameter of each parallel hole (33) is 0.3-0.9 mm; the length of the parallel hole (33) is 0.3-0.9 mm; when one end of the heat exchange tube (2) protrudes out of the forging (1), the parallel hole (33) is formed in the inner wall (23) of the heat exchange tube and below the upper surface (1) of the forging (1) in a direction perpendicular to the tube wall (21) of the heat exchange tube, wherein the central axis of the parallel hole (33) is 1-8mm away from the upper surface of the forging (1);

when one end of the heat exchange tube (2) is flush with the forged piece (1), the parallel holes (33) are punched in the direction perpendicular to the tube wall (21) of the heat exchange tube on the inner wall (23) of the heat exchange tube and below the junction of the surface of the welding line and the inner wall (23) of the heat exchange tube, wherein the central axis of the parallel holes (33) is parallel to the upper surface of the forged piece (1) and is 3-15mm away from the upper surface of the forged piece (1).

7. The sensitivity sample according to claim 3, characterized in that: the toe welding holes (34) are cylindrical, and the diameter of each toe welding hole (34) is 0.3-0.9 mm; the length of the toe welding hole (34) is 0.3-0.9 mm;

when one end of the heat exchange tube (2) protrudes out of the forging (1), the weld toe holes (34) are punched in the direction perpendicular to the forging (1) at the junction of the weld joint surface and the upper surface of the forging (1), wherein the hole edges of the weld toe holes (34) are circumscribed with the weld toes;

when one end of the heat exchange tube (2) is flush with the forged piece (1), the weld toe holes (34) are punched in the direction perpendicular to the forged piece (1) at the junction of the weld joint surface and the upper surface of the forged piece (1), wherein the hole edges of the weld toe holes (34) are circumscribed with the weld toes.

Images