JP2994852B2 - Ultrasonic probe for boiler tube flaw detection - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a suitable boiler tubes flaw ultrasonic probe to testing the thickness reduction of Crack or tubes that occur attachment hardware welds etc. of the boiler tubes.

[0002]

The attachment hardware welds boiler tubes BACKGROUND OF THE INVENTION In thermal power boiler superheater and reheater or the like, starting, generated fatigue Crack due to thermal stress caused by the stop and the tube also hot corrosion and ash The thickness is reduced by cutting and the like, which causes stress corrosion cracking and the like. However superheater and reheater or the like can not approach the Surveyor for tube spacing is narrow and 50 to 100 mm, confirmation of such fatigue Crack and thickness reduction Therefore conventionally is carried out by taking samples tube I have. However, this method is a sampling inspection, and there are concerns about oversight due to limited inspection locations. As one of the solutions, in recent years using a water immersion type ultrasonic testing method, the thickness reduction of Crack or tubes that occur attachment hardware welds etc. of boiler tubes, ultrasonic feeler from the inside of the tube Nondestructive testing methods using offspring have been studied and applied experimentally.

[0003] Thus, the thickness reduction of deposition tube axis direction has occurred in hardware welds or the like and the circumferential Cracks and tube boiler tube, from the inside of utilizing water immersion type ultrasonic testing method tube when testing using an ultrasonic probe, now, ultrasonic probe dedicated required for each flaw, i.e. axial direction of the tube turtle裂探wound probe, ultrasonic probe circumferential turtle裂探scratches , three types of ultrasonic probe for flaw detection thickness reduction, is inserted into the tube by the sort with each, it is carried out each flaw individually. However, this method, the time required for replacement with for insertion, take longer time such inspection required for the flaw detection, poor working efficiency, boiler tube of interest in the process that is allowed for inspection There is a possibility that 100% inspection may be difficult.

[0004]

The present invention 0005] is reduced such was proposed in view of the circumstances, in the tube axis direction and the circumferential direction generated to adhere hardware welds boiler tubes Crack and tube Inspection of meat quantity can be performed at almost the same time by inserting one time per boiler tube of one loop
It is an object of the present invention to provide an ultrasonic probe for boiler tube flaw detection.

[0005]

Means for Solving the Problems The voice of the present invention to its
Ultrasonic probe for boiler tube inspection
The amount of cracks in the axial direction and circumferential direction of the pipe
Probe to be inspected by water immersion ultrasonic flaw detection from
Movement in the pipe axis direction while inserted in the pipe and
A probe body that can rotate around the same tube axis, and the probe body
That emits ultrasonic waves in a direction perpendicular to the inner surface of the tube.
Check the shape and position of the weld bead and
At least one vertical probe for performing the measurement, and
Super sound mounted on the transducer body as a pair back to back
The wave is directed in the direction of the tube axis in the plane including the center line of the tube.
Ultrasonic waves are radiated in the inclined direction, and cracks in the circumferential direction
For inspection of at least one pair of circumferential cracks for inspection
Angle beam probe and the same probe supported by the above probe body
Probe support hand to which a biasing force is applied to the body in the radially outward direction
Step and the probe body through the probe support means
Center line of the tube supported mutually as a back-to-back pair
Eccentric from the center line in a plane perpendicular to
Inspection of the cracks in the pipe axis direction by emitting waves
At least one pair of tube axial crack inspection transducers
And radially outward of the probe body of the probe support means
Inspection of pipe cracks in the axial direction by limiting the amount of deviation
For adjusting the amount of eccentricity of the probe for use in the radial direction outward of the tube
Eccentricity adjusting means .

[0006]

According to the ultrasonic probe for flaw detection of a boiler tube according to the present invention, the amount of cracks generated in a welded part of a boiler tube and the thickness of the tube can be reduced by water immersion ultrasonic flaw detection from the inside of the tube. Since non-destructive inspection can be performed, 100% inspection is possible even for boiler tubes such as superheaters and reheaters that cannot be accessed by the inspector, and it is not necessary to grind the outer surface of the tube or remove scale for inspection. Also during the inspection of thickness reduction of Cracks and tubes of conventional attachment hardware weld the tube axis direction and the circumferential direction generated in such, what was needed a ultrasonic probe flaw of each dedicated, each role by having a lifting one probe is set as probe complex and allows composite inspection and becomes substantially the same time in a single tube inserted for one loop boiler tubes, extremely workability improves.

[0007] In order to assemble a plurality of flaw-detecting probes as a composite probe, the respective probes are arranged by a mounting method of the probe as found in each dedicated flaw-detecting probe. In such a case, the length of the composite probe in the tube axis direction may be increased, and the permeability in a curved tube portion or the like may be deteriorated. for that reason
To the tube axis direction and the probe of the pair for circumferentially turtle裂探wound back to back, respectively, the short reduction by ultrasonic radiation axis is mounted in a state of emitting the same a and 180 DEG different directions I'm trying.

[0008]

When an embodiment of EXAMPLES boiler tube flaw ultrasonic probe of the present invention will be described drawings, Figure 1 shows the present probe, FIG (a) is a side view, and FIG. (B) Is a front view,
FIG. 2 is a longitudinal sectional view of the rotating mechanism, FIG. 3 is an explanatory view of an inspection procedure using a vertical probe, FIG. 4 is an explanatory view of an inspection procedure using an oblique angle probe for pipe axis direction crack inspection , and FIG. Circumferential crack inspection
Illustration of the test procedure according to the angle probe for 査, 6 is a side view showing an aspect in which the present probe to pass through the curved pipe section, FIG. 7 embodiment the probe is testing the adhesion hardware welds FIG. 8 is a perspective view showing
FIG. 4 is an explanatory diagram of the alignment jig in the above.

In FIG. 1, a vertical probe for inspecting the pipe wall thickness and confirming the shape of a weld bead is provided at the center of a probe main body 7 which can be moved in the pipe axis direction and rotated about the pipe axis. 8 is mounted, the probe in front of the main body 7 of the tube axis direction crack <br/> inspected for the tube axis direction crack inspection angle probe 9a, 9
with b are mounted back to back, the circumferential crack inspection for inspecting a circumferential crack in the rear of the probe body 7
査 for the angle probe 10a, 10b are mounted back to back. A cantilever 11 serving as a probe support means is pivotally supported on the probe main body 7 by a pin 12. The cantilever 11 has an oblique angle probe 9a for pipe direction crack inspection . 9b is mounted and supported . The cantilever 11 by the spring 13 and the pin 12 attached to the fulcrum, always and biased radially outward i.e. pipe diameter direction of the outer tube <br/> so, it is charged to the probe body 7 Probe eccentricity
The amount of deviation is restricted by the eccentric amount adjusting ring 14 as the adjusting means and the ring fixing cap nut 15, and the cantilever 11 can only be deviated to the position where it contacts the ring 14, so the eccentric amount as the probe eccentric amount adjusting means Adjustment ring
14 and the cap nut 15 for fixing the ring,
The amount of eccentricity of the crack inspection bevel probes 9a and 9b can be adjusted to the optimum amount of eccentricity according to the specifications of the tube.

In order to hold the probe body 7 on the center line of the tube axis, a spring shaft 1 is provided at both ends of the probe body 7.
6 is attached, and an alignment jig is attached. As shown in FIG. 2, the spring shaft 16 is directly connected to bearings 18 attached to both ends of the probe main body 7, and the vertical probe 8 and the oblique angle probe 9 for crack detection in the tube axial direction.
a, 9b and bevel probes 10a, 10 for circumferential crack inspection
probe body 7 b and is mounted, is rotated in the circumferential direction by a rotary shaft 17 which is spring shaft 16 and the double structure. That it is built bearing 18 between the probe body 7 and the spring shaft 16, since the probe body 7 and the rotary shaft 17 is directly connected by fixing screws 19, the rotary shaft 17
The probe body 7 also rotates with the rotation of.

In such an ultrasonic probe, the shape and position of the weld bead are confirmed by the vertical probe 8 and the thickness of the weld bead is reduced.
For measuring cracks, angle probe 9a,
9b and bevel probes 10a and 10b for circumferential crack inspection
Described FIGS an outline of detecting the Crack by. 3, 4 and 5, 1 boiler tubes, 2a is the pipe axis direction attachment fittings, 2b are circumferentially attached hardware, 3a are axial direction of the tube welding unit, 3b are circumferential welds, 4
a is the tube axis direction Cracks, 4b are circumferentially Cracks, 5 water, 6 denotes a reduced thickness portion. First, FIG. 3, as well as examining the reduced thickness portion 6 of the boiler tubes 1 vertical probe 8, the weld 3
The vertical probe 8 is held on the center line of the tube in the diametric direction , and actually rotates in the circumferential direction and in the axial direction of the tube. Inspection of the thinning amount of the thinned portion 6 of the pipe and confirmation of the shape and position of the bead of the welded portions 3a and 3b are performed while moving to. When the vertical probe 8 is at the position C in the tube axis direction, an ultrasonic multiple echo is obtained by the thinned portion 6 of the tube. Similarly, when the vertical probe 8 is at the position B in the tube axis direction, the thickness of the base material of the tube is obtained. Is obtained. On the other hand, when the vertical probe 8 is at the position in the tube axis direction a or the position in the tube axis direction d, the ultrasonic wave incident on the tube material propagates into the welded portions 3a and 3b, and Diffuse reflection on the outer surface and no ultrasonic reflected echo can be obtained .

[0012] Figure 4 was generated in the tube axis direction welded portion 3a of the tube axis direction with <br/> Chakkin product 2a of boiler tubes 1 tube axis direction turtle <br/> crack 4a, the direction of the defect detection pair considering tube axis crack inspection angle probe 9a, shows the case of inspecting the 9b, the tube axis direction crack inspection angle probe 9a, 9b
The after having back to back to each other the side that does not emit ultrasound, a position where the detection of Crack in a diametrical direction perpendicular a and the tube to the tube axis is offset from the center line of any amount δ by the tube with the maximum It shows how it is held and rotates in the circumferential direction of the tube , i.e. around the tube axis, and moves in the tube axis direction. FIG. 5 shows the metal fitting 2 attached in the circumferential direction of the boiler tube 1.
circumferentially Crack 4b occurring circumferentially welded portion 3b of b
A pair of circumferential crack inspections considering the directionality of the defect detection
Use the angle probe 10a, it shows a case of inspecting the 10b, circumferential cracks test angle probe 10a, 10
b, the sides that do not emit ultrasonic waves back to back,
Defects detected in the plane including the center line is inclined against the only tube axis direction angle θi of maximum are held together, the tube
2 shows a state of rotating in the circumferential direction, that is, around the tube axis and moving in the tube axis direction.

[0013] Figure 6 is for probe body 7 is showing how to pass through the curved pipe portion, because both ends of the probe body 7 is supported by the spring shaft 16, the song of boiler tubes 1 Easy passage through the tube.

Furthermore, when explaining the mode of flaw detection near with circumferential attachment fittings welded portion of the boiler tubes by using the ultrasound probe 7 for, the probe main body 7 attached to the front and rear thereof The centering jig 20 holds the boiler tube 1 on the tube axis center line. As a result, the probes 8, 9a, 9b, 10a, and 10b are always sent in the pipe axial direction by running water while rotating inside the boiler tube 1 under constant conditions. confirmation of shape and position, the further examination of the attached hardware generated the weld such tube axis direction and the circumferential direction of crack performed. In the drawing , reference numeral 21 denotes an alignment jig holding spring, 22 denotes a holding spring adjusting nut, 23
Indicates a guide.

[0015] Here, to describe the structure of the aligning mechanism and the guide 23 of the aligning jig 20, the aligning jig 20 is using nylon wires 24 to the material, a share was equivalent at the time of manufacture <br / > length of Rinomoto line number and element lines are managed, as shown in FIG. 8, when the diameter of the aligning jig 20 is larger than the inner diameter of the tube,
The nylon wire 24 is uniformly crushed, and the probe main body 7 can be aligned. In this case , if the alignment of the probe main body 7 is poor, each of the probes 8, 9a, 9b,
The holding conditions of the pipes 0a and 10b with respect to the tube axis and the like are not constant, and the inspection performance is reduced or the inspection becomes impossible. The guide 23 is formed by attaching a Teflon ball to the tip of the spring shaft 16 and prevents the tip of the spring shaft 16 from catching on a projection such as the inner surface of a welded portion.

Thus , according to such an ultrasonic probe, the inside of the boiler tube 1 is subjected to a water immersion method to reduce the thickness of the thinned portion 6 of the boiler tube 1 and to the adhered metal welds 3a, 3b. the resulting cracks 4a, since it is 4b inspection, removal, etc. of abrasive and scale of extravascular surface for inspection is not required. The vertical probe 8 to check the thickness reduction of the tube,
By utilized for confirmation of the shape and position of the weld bead, tube axial direction crack inspection angle probe 9a, 9b and
Circumferential crack inspection angle probe 10a, cracks 4a occur by Ri soluble <br/> contact portion or the like 10b, when inspecting the 4b, and determination of the identity and the positional relationship between the weld bead and the defect Make it easy. In addition , bevel probes 9a and 9b for detecting cracks in the axial direction of the tube and the circumference thereof.
Direction crack inspection angle probe 10a, 10b, because they are attached in the form of back-to-back in pairs each weld root portion and regardless weld toe portion, always corner portion formed by the tube surface and Crack The ultrasonic wave of either one of the channels can be incident on the tube, so that the inspection can be performed regardless of the direction of the tube axis feed. occurs attachment hardware weld such tube axis direction and in the circumferential direction
Can inspection of turtle crack, it is possible to extremely workability good precision inspection. Further, it is supported by being supported by the probe main body 7.
The cantilever 11 as the probe support means
Attempts to deviate outward in the radial direction of the pipe, and the amount of deviation is
As a means for adjusting the eccentricity of the probe set in the probe body 7
Eccentricity adjustment ring 14 and ring fixing cap nut 15
As a means for adjusting the probe eccentricity.
Eccentricity adjustment ring 14 and ring fixing cap nut 15
Of eccentricity of the bevel probes 9a and 9b for crack inspection in the pipe axis direction
The amount of eccentricity can be adjusted to the optimum eccentricity according to the specifications of the pipe.
You.

[0017]

In summary , the boiler tube flaw detection of the present invention
According to the ultrasonic probe for the boiler tube
Water immersion from inside the pipe and the amount of cracks and pipe wall loss in the circumferential direction
A probe to be inspected by ultrasonic flaw detection.
Move in the above-mentioned pipe axis direction and around the pipe axis while inserted
The probe body that can rotate
Ultrasonic waves are emitted in a direction perpendicular to the pipe inner surface to
Check the shape and position of the pipe and measure the amount of wall thinning
At least one vertical probe for use with the probe body
The ultrasonic wave is mounted as a pair back to back on each other
In the plane containing the center line of
Radiates ultrasonic waves in the direction of the crack to inspect for circumferential cracks
Probe for inspection of at least one pair of circumferential cracks
And the diameter of the probe body supported by the probe body
A probe supporting means to which a biasing force to the outside is applied;
The probe bodies are mutually opposed via the probe support means.
It is supported as a pair with the center set and is perpendicular to the center line of the tube.
Emitting ultrasonic waves eccentric from the center line in a straight plane
Inspection for cracks in the pipe axis direction.
At least one pair of probe for tube crack inspection in the axial direction and the above probe
The amount of displacement of the probe support means radially outward of the probe body is
By restricting the probe above the pipe
Probe eccentricity adjustment to adjust the eccentricity outward in the radial direction of the tube
Means , the boiler tube
The amount of thinning and adhesion of the thinned part of the boiler tube from inside
Inspection of cracks generated in metal welds, etc.
There is no need to grind the outer surface of the pipe or remove scale, etc.
The vertical probe for checking the wall thickness is the shape and position of the weld bead.
It can be used to check the cracks in the pipe axis direction.
Bevel probe for inspection and bevel probe for circumferential crack inspection.
When inspecting cracks that occur in welds, etc.,
It is easy to identify cracks and judge the positional relationship.
Bevel probe and circumferential turtle
Bevel probes for crack inspection are paired
Since it is mounted in a shape, the welding root and toe
Irrespective of the
Ultrasonic wave of either channel is incident on the
Can be inspected regardless of the direction of tube axis feed.
In each case, one tube for one loop boiler tube
At the same time with internal insertion, wall thinning of the pipe and welded parts
Inspection of cracks in the axial direction and circumferential direction of the pipe
It is possible to carry out precise inspection with very good workability.
And the probe supported by the probe body.
The stylus support means always tries to deviate radially outward of the tube.
And the amount of the deviation is the probe supported by the probe body.
The probe is controlled by the eccentricity adjustment means,
The amount of eccentricity of the bevel probe for pipe direction crack inspection by the joint means
Can be adjusted to the optimal amount of eccentricity according to the specifications of the pipe,
Ultrasonic probe for boiler tube flaw detection which is extremely useful in industry
A child can be provided.

[Brief description of the drawings]

1 shows an embodiment of an ultrasonic probe for boiler tube flaw detection according to the present invention, wherein FIG. 1 (a) is a side view and FIG. 1 (b) is a front view.

FIG. 2 is a longitudinal sectional view of the rotation mechanism of the same.

FIG. 3 is an explanatory view of an inspection procedure using a vertical probe.

FIG. 4 is an explanatory view of an inspection procedure using a tube axis direction crack inspection oblique probe.

FIG. 5 is an explanatory view of an inspection procedure using a bevel probe for circumferential crack inspection .

FIG. 6 is a side view showing a mode in which the probe according to the present invention passes through a curved tube portion.

FIG. 7 is a perspective view showing an embodiment in which the probe according to the present invention detects a flaw in a deposited metal weld.

FIG. 8 is an explanatory view of the centering jig in the embodiment.

[Explanation of symbols]

1 boiler tubes 2a tube axis attachment fittings 2b circumferentially attached fittings 3a tube axial welds 3b circumferential welds 4a tube axis Crack 4b circumferentially Crack 5 water 6 thinning portion 7 probe body 8 Vertical probe 9a, 9b Bevel probe for pipe direction crack inspection 10a. 10b Oblique probe for circumferential crack inspection 11 Cantilever 12 Pin 13 Spring 14 Eccentricity adjusting ring 15 Ring nut for fixing ring 16 Spring shaft 17 Rotary shaft 18 Bearing 19 Fixing screw 20 Alignment jig 21 Aligning jig Pressing spring 22 Pressing spring adjusting nut 23 Guide 24 Nylon wire

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁶ , DB name) G01N 29/00-29/28

Claims (1)

(57) [Claims] 1. The direction of the tube axis and the circumferential direction of the boiler tube
Immersion ultrasonic inspection from inside the pipe to determine the direction of cracks and wall thickness reduction
A probe to be inspected by the
It is possible to move in the above-mentioned pipe axis direction and rotate around the pipe axis in this state.
Of the active probe and the inner surface of the tube mounted on the probe
To radiate ultrasonic waves in the vertical direction to
To check the position and position of the pipes and to measure the thickness of the pipes.
At least one vertical probe and the probe
In-plane including the center line of the above-mentioned tube, mounted as a pair
Radiate ultrasonic waves in a direction inclined with respect to the pipe axis direction.
At least one of the following:
Angled probe for paired circumferential crack inspection and the above probe body
The biasing force of the probe body in the radially outward direction is
The probe support means provided and the probe body
Paired back to back via the probe support means
Supported in a plane perpendicular to the centerline of the tube.
By emitting ultrasonic waves eccentrically from the center line,
At least one pair of tube shafts for inspection for axial cracks
A probe for directional crack inspection and the probe for the probe support means.
By limiting the amount of radial displacement of the main body
The probe for the tube axial direction crack inspection is directed outward in the tube radial direction.
A probe eccentricity adjusting means for adjusting the eccentricity.
An ultrasonic probe for boiler tube flaw detection.