CN205449833U - Accurate detectable material's of digit ray transillumination technique defect and device of thickness - Google Patents

Abstract

Accurate detectable material's of digit ray transillumination technique defect and device of thickness belongs to the nondestructive test field. The test block of taking fixed slope, place on by detectable material, pass detected workpiece simultaneously when having fixed slope's test block when ray field from top to bottom, receive the dull and stereotyped ray after the decay of receiving by digital ray, by data display processing unit convert to the twodimensional diagram like, to the detection of dull and stereotyped welding seam, take fixed slope's test block to place on the detected workpiece next door, this test block is right trapezoid's test block for the cross -section, wherein the right -angle side level place with the work piece on a horizontal plane, detect to path pipe, use the cross -section as half circle ring take the slope test block, this test block axial direction's cross -section is half circle ring, the cross -section of circumference orientation is right trapezoid, the cross -section takes the internal diameter of slope test block to equal the external diameter that the path was managed for half circle ring's, and test block closely parcel is just placed on the welding seam next door outside detected workpiece. This device can the precision measurement defect high, weld reinforcement etc. The erroneous judgement can not appear.

Description

Prospect of Digital-Radiography accurately detects the defect of material and the device of thickness

Technical field

The utility model discloses Prospect of Digital-Radiography and accurately detect the defect of material and the device of thickness, belong to field of non destructive testing.

Background technology

1, industrial x-ray transillumination technology

Radioscopy belongs to the one of Non-Destructive Testing, has the methods such as X-ray procedure, gamma-ray examination, high-energy ray inspection and neutron ray inspection.For industrial x-ray is checked, generally use is X-ray procedure and gamma-ray examination.Its principle is: when the beam transillumination of even intensity penetrates object, if object regional area existing defects or structure there are differences, it will change the object decay to ray, make different parts transmitted ray intensity different, so, certain detector (such as, using film in radiography) detection transmitted ray intensity is used, it may determine that the defect of interior of articles and material distribution etc., thus complete the inspection to detected object.

Along with electronics and the development of computer technology, flat panel detector (X-ray penetrated is converted into digital data transmission shows to computer by conversion, save know clearly film and the process developed a film) X-ray direct imaging is used to detect (DR) system and have begun to be widely used in the fields such as industry, safety, research, medical treatment.Digital x-ray DR technology has detection, and speed is fast, highly sensitive, analysis method is enriched, radiate the remarkable advantages such as low, no material consumption.

2, relevant criterion and the test block detection method of industrial non-destructive X-ray procedure is introduced

In June, 2013, No. four decree of chairman that President Xi Jinping promulgates, " People's Republic of China's special safety equipment method " was formally implemented from January 1st, 2014, and special equipment includes boiler, pressure vessel, pressure pipeline, elevator, hoisting machinery, passenger aerial ropeway, large-scale recreation facility, field (factory) interior private motor vehicle etc..These equipment typically have the feature run under high pressure, high temperature, high-altitude, high-speed condition, generation falling from high altitude inflammable, explosive, easy etc., and the person and property safety are had bigger danger.Special equipment produces, manages, uses, checks, detects and should observe relevant special safety equipment technical specification and relevant criterion.

As the ray detection (radiology) of one of five big conventional lossless detection methods, industrial nondestructive testing has a very wide range of applications.The industries such as Aero-Space, electric power, national defence, electric power have relevant industry examination criteria and code for detection." People's Republic of China's industry standard JB/4730 " and " using Regular Inspection of Pressure Pipelines code ", it is stipulated that the requirement of ray detection, process, detection performance rating classification, the definition of defect, measuring method etc..Win as follows:

JB/T4730 " bearing device Non-Destructive Testing " table 6

The maximum of incomplete fusion oneself height in the single welding point that pipeline at different levels was allowed

4730 table 2l pipe outer diameter D₀> 100mm time be not added with the classification that backing plate single welding is lack of penetration

Analyze from above standard and clause, for manufacture process and In service inspection, for pipeline " lack of penetration ' the incomplete fusion degree of depth is required for accurately measuring, assay method is specified by 4730 standards, and employing reference block is carried out.

The size of the special reference block of small diameter tube (I type) see table (unit mm)

Standard it further provides for, and the caliber general reference block more than 100mm uses bar shaped test block, and its flaw size see table (winning JB4730 national standard).

Size mm of table H.2 general reference block (II type)

Standard content and discussion is won by above-mentioned, it is known that at present the grading of Standards for Pipeline welding Defects (lack of penetration, do not merge, undercut etc.) is the blackness by step bar contrast defective locations, again by the size of defect divided by the nominal thickness of pipeline, carry out grading evaluation.

Other standards, as electric power standard " DL/T821-2002 ", oil, national military standard etc. all use similar definition and measuring method: use gradient comparison test block to carry out direct blackness comparison.

Can be summed up by description above: existing defect depth measurement and grading, be all image blackness and the shadow shape blackness contrast realization of defect of the ladder reference block with strip or grooved.And the shortcoming that these methods exist is discussed below:

1, the problem that traditional radiographic photograph detection (measurement film density) exists:

1), accuracy of reading error: effective blackness scope of film is about 1.5-4.0, the identification ability of human eye is 0.006-0.008, about 500 ranks, and nigrometer is in measuring film density, standard regulation error level is about 0.05, the measurement rank of film density meter is 0.05 grade, and every 0.05 blackness is a rank, in effective blackness scope, 1.5-4.0 it is interior, (4.0-1.5)/0.05=50 level, rank is relatively low, and measuring accuracy is restricted.When using digital radial, blackness (being also gray scale) is 14 or 16, and the tonal range 16000 or 65000 of response, precision is higher than film.

2), measurement error: it is generally required to the defect measuring the degree of depth is fine rule type in workpiece, its feature shown on film is thin black line, as lack of penetration, incomplete fusion, undercut etc., the width of this type of defect is typically the least at below 0.5MM, and the well width of grooved reference block is 2MM, for measuring nigrometer, its syringe needle got ready is grade, when for measuring the blackness of grooved test block groove, its position can be found accurately, when measuring fault location blackness, often it is difficult to find its position accurately, one is that defect width is much smaller than syringe needle width, two be egative film be black under available light, human eye is difficult to distinguish its defect exact position, so measurement error is bigger.Equally, process (temperature, liquid medicine, developing time, film the keep environment etc.) difference of film also results in the difference of measurement result.It addition, the eyesight influence of operator, level of skill also can affect measurement result.

2, for digital number ray:

Indistinction is in the Special test block of film at present, correlation standard (JB/4730.11, changing NB47013 in the recent period, started a surname July and pass through) (film) standard as above that is referred to performs, but the method not being embodied as, step, requirement.Reference block at present is when digital radial (DR), although can remove some shortcoming of film detection, but digital radial detection has it to be different from the feature of conventional film, and these exclusive features are to judging to bring trouble.Current comparison test block there is a problem in that:

1) using nigrometer comparative observation, before, it is little that film density scope is typically 1.5-4.0. scope to the maximum, big 1.6 ten thousand or 6.5 ten thousand gray levels of tonal range of digital radial, gradation of image sense organ rises and falls the biggest.It is not easy to choose datum mark to compare.See Figure 1, one section of its grey level of straight line (curve in coordinate frame) that homogenous pipe wall is chosen rises and falls the biggest:

2), each ladder of step bar be right angle, for the digital radial of higher for luminous sensitivity (comparing 1-2 order of magnitude of film height), scattering impact from sense organ from the point of view of bigger.Such as the pipeline interface display that Fig. 2 is the band step bar (grooved) that digital radial shoots, wherein linear graph shows the image of marginal portion of right angle groove, see the position drawn a circle of mark, should be right angle in theory, due to scattering effect its be with the transition numerical value gray scale shaken.This situation can cause user cannot confirm the exact position of comparison when reality detects.

3, more important point is, two kinds of above-mentioned methods all exist the probability of erroneous judgement (inaccurate):

The standard implemented at present and method, only measure the absolute grayscale of defective locations, contrast with the gray scale of artificial defect in gradient test block, whether exceed the artificial defect in test block with the height that this judges defect.But, the method does not take into full account that weld reinforcement changes the impact (gray scale depends on the thickness truly penetrated) bringing gray scale.Such as GB50235 " Industrial Metal pipeline construction specification " requires the reinforcement≤1+0.2b (b is weld groove width) of butt weld and no more than 3mm, so reinforcement the most all disclosure satisfy that construction reference during actual welding.But during Site Detection, highly fixing does not merges defect, when occurring in the reinforcement of reinforcement 2mm and 1mm, its final gray scale necessarily has a difference, and may result in rating result during test block contrast can be different.

And newest standards NB/T47013 that in April, 2015 promulgates (substitutes the latest edition of JB/4730, JIUYUE is implemented on the 1st) require to consider reinforcement difference, and manufacture test block according to reinforcement height (thickness of test block is equal to reinforcement height), but still use the mode of step bar intensity contrast., the scope that the welding surroundings of actual field, personnel's difference etc. determine reinforcement is very big, and the reinforcement of same weld seam rises and falls the biggest, and test block is highly difficult to determine；Such as, during weld seam big rise and fall, how to make reference block and do not have explanation.

Summary of the invention

This utility model can solve the problem that above-mentioned all problems.Specifically it is discussed below:

Ultimate principle foundation: under the conditions of equal transillumination, after the workpiece of the same material that ray passes equal thickness, its gray scale is equal；Equally, when transillumination condition is identical, the material thickness that the position of same grayscale penetrates is the most equal.

1, Prospect of Digital-Radiography accurately detects the defect of material and the device of thickness, it is characterised in that:

Including the test block of band fixed slope, examined workpiece, digital radial receives flat board and data display processing unit；Received the ray after board joint receives decay by digital radial, data display processing unit be converted into two dimensional image；

Test block with fixed slope is placed on examined workpiece side；This test block be cross section be that the test block of right-angled trapezium, wherein right-angle side horizontal positioned and examined workpiece are on a horizontal plane；

2, Prospect of Digital-Radiography accurately detects the defect of material and the device of thickness, it is characterised in that:

Including the test block of band fixed slope, examined workpiece, digital radial receives flat board and data display processing unit；Received the ray after board joint receives decay by digital radial, data display processing unit be converted into two dimensional image；

This test block cross section is the band slope test block of semi-circular shape, and the cross section of this test block axial direction is semi-circular shape, and the cross section of circumferential direction is right-angled trapezium；Cross section is the internal diameter external diameter equal to small diameter tube of the band slope test block of semi-circular shape, and test block tight is outside examined workpiece, and is placed on weld seam side.

When flat board weld seam detection, the test block with fixed slope is placed on examined workpiece side；This test block be cross section be that the test block of right-angled trapezium, wherein right-angle side horizontal positioned and workpiece are on a horizontal plane；

Detecting for small diameter tube, with the band slope test block that cross section is semi-circular shape, the cross section of this test block axial direction is semi-circular shape, and the cross section of circumferential direction is right-angled trapezium；Cross section is the internal diameter external diameter equal to small diameter tube of the band slope test block of semi-circular shape, and test block tight is outside examined workpiece, and is placed on weld seam side；

Pore (reinforcement inner white region) is had in the middle of butt plates welding seam (black examined workpiece in Fig. 3), what placement was close on right side therewith is the test block (white portion) of band slope, when field of radiation from top to bottom is through examined workpiece with the test block of fixed slope, received the ray after board joint receives decay by digital radial, data display processing unit (computer) be converted into two dimensional image.

The method implemented is: the test block (length and the height on inclined-plane are fixed) of known band fixed slope is positioned on detected material, digital radial DR is used to detect, utilize image can realize the feature of digitized processing, can be by inquiring about with gray scale, find and the position of defective locations gray scale equal slopes test block, thus calculate the thickness of this point according to the slope meter of test block.As a example by flat board weld seam detection, illustrate with Fig. 3:

Pore (reinforcement inner white region) is had in the middle of butt plates welding seam (black examined workpiece in Fig. 3), what placement was close on right side therewith is the test block of band slope, this test block be cross section be the test block of right-angled trapezium, wherein right-angle side horizontal positioned and workpiece are on a horizontal plane (white portion), when field of radiation from top to bottom is through examined workpiece with the test block of fixed slope, received the ray after board joint receives decay by digital radial, data display processing unit (computer) be converted into two dimensional image.

On the two dimensional image produced, running through slope test block and time defective locations streaks straight line, computer will reveal whether the grey scale change figure of this line, and See Figure 4 is illustrated.Weld reinforcement position (ray energy loss is bigger) gray scale is minimum, maximum through (energy loss is less) gray scale during defective locations, the X-ray energy loss penetrating slope test block part changes along with the change of thickness, so gray scale is approximately an oblique line.

In Fig. 4, owing to L is the projected length (a length of L0 of actual test block, see Fig. 5) of test block.Found in slope test block by computer and (gray scale is minimum) position (shown in dotted line) that gray scale is equal at weld reinforcement, calculated the length of L1 by it in the projection meter of length coordinate.Equally, find in slope test block and weld defect (gray scale the is maximum) position that gray scale is equal, calculated the length of L2 by projection meter.

The physical parameter of test block is known, with reference to test block side cross-sectional, view:

The length of L0: test block, it is known that amount

L1, L2: computer is measured

(the band slope portion) of H: test block highly, it is known that amount

So, relative altitude H1 of weld reinforcement position gray scale can be calculated by formula:

H1=(H/L0) * L1* (L0/L) draws the height (relative altitude, only corresponding slope portion) of weld reinforcement

(note: the gross thickness of the nominal wall thickness of the minimum constructive height+pipeline of this numerical value+slope test block=reinforcement position)

Same method can calculate relative altitude H2 of gray scale at weld defect:

H2=(H/L0) * L2* (L0/L) (relative altitude, only corresponding slope portion)

Both subtract each other the height obtaining defective locations: flaw height=H1-H2.

The method can accurately measure the height of defect, weld reinforcement, thinning (the test block thickness range be suitable for) etc. of workpiece can also be measured, the shape of test block is not at the same time it can also be measure the tested object material thickness such as tubulose, tabular and the thickness of position while welding and flaw height.

Sum up operation element flow process as shown in Figure 6.

For small diameter tube, with the band slope test block that cross section is semi-circular shape.Specific practice can be hollow round table, and hollow is shaped as cylinder, is cut into identical two halves then along axis, and cross section in the axial direction is right-angled trapezium.

Concrete principle is: when the X-ray that radiography unit is launched penetrates small diameter tube, the material thickness that the X-ray of diverse location actually passes through differs, seeing that Fig. 9 illustrates, the thickness of A, B, C point penetrable material differs greatly, and (central ray penetration thickness is minimum, and both sides become big；The pipeline being relatively large in diameter then difference is the least, and the biggest difference of caliber is the least).If, test block be in strip and be positioned over (pipeline location of B point correspondence) in the middle of pipeline carry out transillumination and measure be pipeline marginal position time, the actual (real) thickness then penetrated due to the ray of pipe centerline both sides becomes larger (see Fig. 9, the penetration thickness of A and C is more than B), then gray scale can be caused to taper into；When there is such grey scale change, just cannot measure thickness and the flaw height of A and C point with the slope test block of B point position.

If it is that outside examined workpiece and weld seam side is (on the right of weld seam for semi-circular shape tight that cross section is made in test block, see Figure 10), then can ensure that the position of measuring of whole weld seam scope (projection) the most all has the test block slope gray scale axially in parallel with pipeline to contrast, it is to avoid thickness changes the gamma error caused.

When ray irradiation down over from picture, digital radial flat receiver generates two dimensional image.On image, running through slope test block and time defective locations parallelpiped axial direction draws a straight line, computer will reveal whether the continuous gray scale change curve of this line, See Figure signal (it is just the same that this figure and plate welding before detect picture)；Due to test block be cross section be semi-circular shape, so the impact that this grey scale curve avoids pipeline center when (synchroballistic) ray penetrates small diameter tube and edge thickness difference is brought more greatly.Ensuing detecting step is identical with discuss before with computational methods.

Key problem in technology point of the present utility model and to be intended to protect be a little what

1, use band fixed slope test block for the protection that Thickness sensitivity is used by digital radial DR detection technique (without CT), the lossless decomposition including pipeline, flat board, throat depth detection and material internal defect height detection.

2, under the conditions of applying equal transillumination, the principle that the thickness of the point that gray scale is identical is equal, calculate material relative thickness, the method for flaw height by fixed slope test block.

Accompanying drawing explanation

Fig. 1 is one section of its grey level of straight line chosen on homogenous pipe wall.

Fig. 2 is the pipeline interface display of the band step bar (grooved) for digital radial shooting.

Fig. 3 is this utility model device schematic diagram.

Fig. 4 is from left to right direction gray scale and detection schematic diagram after computer generated image.

Fig. 5 is with reference to test block sectional view.

Fig. 6 is workflow diagram.

Fig. 7 is test block side view section figure.

Fig. 8 is test block axonometric chart.

Fig. 9 is that pipe with small pipe diameter ray penetrates schematic diagram.

Figure 10 test block layout drawing.

Figure 11 test block schematic diagram.

Figure 12 gray scale and detection schematic diagram.

Detailed description of the invention

Time: on July 15th, 2015

Workpiece situation: steel plate+band slope test block+gradient step bar

Testing goal: checking uses band fixed slope test block to measure the depth difference (flaw height within simulation weld seam) of two defects of gradient test block with (steel plate) background

The equipment introduction used:

Equipment: use U.S.'s Varian 2520 flat panel detector

Use ICM company of Belgium CP160 radiography unit

Workpiece and test block describe:

1,7mm steel plate, as background (simulation pipeline or the thickness of flat board).

2,3.5mm thicker strip has 5 step trough test blocks (see the H.2II type reference block of table above, the degree of depth is respectively 0.5,1.0,1.5,2.0,2.5), we only use first defect (degree of depth 0.5mm, test block real surplus thickness 3mm) and the depth difference of second defect (degree of depth 1mm, test block real surplus thickness 2.5mm) simulate the flaw height in weld reinforcement.

3, thickness 2--3.5mm fixed slope test block, effective length 11.5mm, as shown in Figure 7:

Note: the consideration that test block manufactures:

A, band fixed slope: this experiment is, 1.5:11.5

B and the same material of tested material, same to condition, (with material steel)

C, the gray scale of guarantee measured position can find equal point in slope test block tonal range.

Detection method:

At 7mm surface of steel plate plastic adhesive tape, the test block of band slope and the test block of band step trough are firmly pasted.Use voltage 120KV, electric current 0.3mA, 1 second transillumination time, use the mode of 10 two field picture superpositions, obtain image, treated as follows:

Calculating process:

Can be obtained by explanation before, the height H=3.5-2=1.5mm of slope test block, length L0=11.5；Length projected length L=11.51；

Find the H1 position that the gray scale of the position of defect 1 is corresponding, measure H1=(1.5/11.5) * 7.84* (11.5/11.51)=1.02 (rounding up) mm through formula；

Same manner finds the H2 position that the position gray scale of defect 2 is corresponding, measures H2=(1.5/11.5) * 4.26* (11.5/11.51)=0.56mm (rounding up) through formula；

The difference of defect 1 and defect 2 is: H1-H2=1.02mm-0.56mm=0.46mm

Owing to the gradient of each groove of step bar (make according to national standard and have certificate of measurement and weight) is 0.5 millimeter (known), so this test error is:

(0.5-0.46)/0.5=0.08

This utility model effect

1, the thickness of the relative thickness of optional position, defective locations can be measured more accurately, after subtracting each other, obtain the precise height of defect.

2, due to this method be use compare measure absolute value method, so this method is applicable to abnormally-structured detection.Such as aircraft blade, owing to structure is complicated, method before the Minute pores occurred in its manufacture process uses is less susceptible to carry out to detect that (difference in thickness is big, complex-shaped, defect is the least, test block is caused to be difficult to manufacture), if employing this method, only considering that total penetration thickness and the defect definition of blade can make test block, the problem measuring flaw height then can solve.

3, in addition to strip test block (this is tested and uses), this test block can make semi-circular flaw height in the weld reinforcement thickness detecting small diameter tube and reinforcement.JB4730.2 standard (ray detection) specifies, the pipe external diameter pipeline equal to less than 100mm is small diameter tube, and the ladder reference block of small diameter tube needs to use semicircle test block to carry out detecting (see above small diameter tube I type reference block requirement)；This inventive method is equally applicable to this principle.Semicircle (band slope) the test block reason of employing is: when the X-ray that radiography unit is launched penetrates small diameter tube, the material thickness that the X-ray of diverse location actually passes through differs, See Figure is illustrated, the thickness of A, B, C point penetrable material differs greatly, and (central ray penetration thickness is minimum, and both sides become big；The pipeline being relatively large in diameter then difference is the least, and the biggest difference of caliber is the least).If, test block be in strip and be positioned over (pipeline location of B point correspondence) in the middle of pipeline carry out transillumination and measure be pipeline marginal position time, the actual (real) thickness then penetrated due to the ray of pipe centerline both sides becomes larger (see Fig. 9, the penetration thickness of A and C is more than B), then gray scale can be caused to taper into；When there is such grey scale change, just cannot measure thickness and the flaw height of A and C point with the slope test block of B point position.

If test block makes semicircle tight on examined workpiece weld seam side (on the right of weld seam, See Figure), then can ensure that the position of measuring of whole weld seam scope (projection) the most all has the test block slope gray scale axially in parallel with pipeline to contrast, it is to avoid thickness changes the gamma error caused.

When ray irradiation down over from picture, digital radial flat receiver generates two dimensional image.On image, running through slope test block and time defective locations parallelpiped axial direction draws a straight line, computer will reveal whether the continuous gray scale change curve of this line, See Figure signal (it is just the same that this figure and plate welding before detect picture)；Due to test block be cross section be semicircle, so the impact that this grey scale curve avoids pipeline center when (synchroballistic) ray penetrates small diameter tube and edge thickness difference is brought more greatly.Ensuing detecting step is identical with discuss before with computational methods.

4, for the detection of integument internal material, an integument can be removed and place test block shooting, then shoot the integument with condition by identical condition.Again the defective locations of test block image cut to the response of the actual image that should detect, the method re-using discussion same as above measures.

Concluded that by above discussion, experiment

This utility model uses without gradient fixed slope (slope and thickness can make according to detection demand), the digitized feature that makes full use of digital radial DR, uses gray scale ratio method measurement material thickness, flaw height absolute value.Its advantage is summarized as follows:

The error that before this method reducing, described detection mode, certainty of measurement are brought.

Avoid the impact (e.g., weld reinforcement out-of-flatness) of field condition.

Reduce the quantity thickness test block of plurality of specifications (test block can substitute) of on-the-spot test block.

Measurement result is more accurate, it is to avoid the potential safety hazard that erroneous judgement brings.

Substantially increasing detection efficiency, be exemplified below: according to the NB47013 examination criteria of in April, 2015 up-to-date promulgation, during field pipes welding inspection, the thickness of test block is equal with the reinforcement of weld seam；But the reinforcement of the weld seam at scene welds custom, weld seam environment etc. with individual exists larger difference.Like this, the reinforcement of each weld seam is required to measure actual height, and manufactures the test block of respective thickness；If using the slope test block of certain scope, then can save these steps.

The method can be quick, feasible accurately survey flaw height, material thickness, solve use traditional method and than test block detection problems be a kind of innovation, feasible ray detection method.

1, the test block of band slope can be divided into flat-type to detect bar shaped test block, small pipeline class semicircle test block (Large Diameter Pipeline flat board test block), anisotropic approach test block (needing the transillumination condition of simulated defect position when special shape, condition) according to detection shape, can be divided into the detection of weld reinforcement position, mother metal Thickness sensitivity (corroding thinning, internal porosity etc.) according to testing requirement.Use the method can measure the thickness of the thickness of optional position, defective locations more accurately, the height of defect is obtained after subtracting each other, the polymorphic structure that is not easily solved before solving (be unfit to do test block, certainty of measurement poor) problem, such as aircraft blade interior spilehole etc..

2, the method makes full use of computer technology, for the detection of integument internal material (such as ammonia refrigeration pipeline), can remove an integument and place test block shooting, then shoot the integument with condition by identical condition.Again the defective locations of test block image cut to the response of the actual image that should detect, the method re-using discussion same as above measures.

Claims (2)

1. Prospect of Digital-Radiography accurately detects the defect of material and the device of thickness, it is characterised in that:

Including the test block of band fixed slope, examined workpiece, digital radial receives flat board and data display processing unit；Received the ray after board joint receives decay by digital radial, data display processing unit be converted into two dimensional image；

Test block with fixed slope is placed on examined workpiece side；This test block be cross section be that the test block of right-angled trapezium, wherein right-angle side horizontal positioned and examined workpiece are on a horizontal plane.

2. Prospect of Digital-Radiography accurately detects the defect of material and the device of thickness, it is characterised in that:

Including the test block of band fixed slope, examined workpiece, digital radial receives flat board and data display processing unit；Received the ray after board joint receives decay by digital radial, data display processing unit be converted into two dimensional image；

This test block cross section is the band slope test block of semi-circular shape, and the cross section of this test block axial direction is semi-circular shape, and the cross section of circumferential direction is right-angled trapezium；Cross section is the internal diameter external diameter equal to small diameter tube of the band slope test block of semi-circular shape, and test block tight is outside examined workpiece, and is placed on weld seam side.