JP3132385B2 - Inspection position determination method for metal weld section - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for determining an inspection position of a cross section of a metal weld, which determines the inspection position of the test piece of the metal weld cross section in relation to the metal structure of the weld and the contour of the test piece. Calculate the hardness by automatically pressing the indenter with a predetermined load to determine the size of the indentation generated on the surface of the test piece, suitable for application to hardness measurement using a so-called automatic hardness meter or automatic micro hardness meter, The present invention relates to a method for determining an inspection position of a cross section of a metal welded portion, which can automatically and efficiently determine an inspection position.

[0002]

2. Description of the Related Art The main purpose of inspecting the hardness of a cross section of a metal weld is to check whether or not the hardness range for preventing cracking defects such as hydrogen cracking is satisfied. Since the thermal history greatly changes depending on the position, it is necessary to continuously inspect a large number of positions (about 100 points per test piece).

For example, in the case of a cross section of a welded portion of a UOE pipe, as shown in FIG. 1, at an inspection position x at which a predetermined distance has entered the inside of a test piece 10 along an arc-shaped contour CT,
A large number of positions are comprehensively inspected for various metal structures such as the molten metal portion 12, the heat affected zone 14, and the base metal 16.

[0004]

If it is possible to efficiently determine a number of inspection positions as described above in a welded section and register them in an automatic hardness tester, it is possible to expect significant labor savings in inspection work. However, conventionally, there is almost no technology in this field, and since the inspection position relied on skilled work in which an operator determines a scribing and a micrometer, especially when measuring on a curve, it takes about one hour. It becomes continuous work,
Not only did it take a lot of man-hours, but also the burden on the workers.

As a method of determining an inspection position (an indentation point at which an indenter should be pressed) of an automatic hardness measuring device, the applicant has already disclosed in Japanese Patent Application Laid-Open No. 60-143739 an image obtained by imaging a sample to be measured. To determine the embossing point by image processing. Specifically, for the standard metallographic structure,
A text file in which a reference feature amount indicating a texture feature is obtained is stored, and the feature amount of the sample obtained by calculation and the reference feature amount are statistically compared by the maximum likelihood method to obtain the tissue of the sample. By classifying based on the texture information, for example, a bond portion which is a boundary between the molten metal portion and the heat-affected zone is automatically detected as a boundary between two different texture regions. Furthermore, the position of the embossing point is
For example, when embossing at a pitch of 0.5 mm in a direction perpendicular to the bond portion, the embossing point is automatically determined and registered simply by inputting the embossing start point and pitch information. .

The method of determining the embossing point, ie, the inspection position, described in Japanese Patent Application Laid-Open No. Sho 60-143739 is effective when determining the inspection position based only on the bond portion, but takes the contour of the test piece into consideration. There was a problem that was not.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems. It is possible to efficiently determine and register a large number of inspection positions in a cross section of a metal welded portion, and to greatly reduce the labor for inspection work. And to eliminate individual differences.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a method for determining an inspection position of a metal-welded section in which the inspection position of the metal-welded section test piece is determined in relation to the weld metal structure and the contour of the test piece. An image of the metal weld cross section test specimen is taken and
Specify multiple points that characterize the contour of the specimen using the image.
The curve representing the contour shape of the test piece Te calculated, the profiled
A predetermined distance from the curve representing the shape, determine a virtual line for arranging and grouping the inspection positions, determine an intersection of the boundary between the virtual line and the metal structure, and a distance along the virtual line from the intersection. Thus, the above-described problem is solved by determining the inspection position.

Further, the imaginary line is determined based on an outline of a test piece contour approximated by an arc or a straight line.

Referring to FIG. 2, a molten metal portion 12, a heat-affected zone 14, a base metal 16 and a test piece 1,
The method according to the present invention will be described by taking as an example the case where the inspection position x is determined in relation to the contour CT of 0. The feature of the present invention is that an image of a metal-welded section test piece is imaged and the image is taken.
Plurality characterizing contour CT of test specimen 10 using image images
Designate a point and specify a curve representing the contour of the test piece (approximately
(Form) GC is calculated, and the inspection positions x are grouped by the distance from the contour CT and are arranged on the virtual line V. That is, in the present invention, as shown in the partially enlarged view of FIG. 3, the outline GC of the contour CT is first determined by approximation of an arc, a straight line, or the like, and the distance L1 from the determined outline GC is determined.
Thus, the virtual line V having a constant distance L1 from the contour is determined. Next, an intersection CR between the virtual line V and the boundary B of the metal structure is determined, and the inspection position x is determined based on a distance L2 along the virtual line V from the intersection CR.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 4 is a front view, partially including a block diagram, showing the configuration of an automatic hardness tester to which the inspection position determining method according to the present invention is applied, and FIG. 5 is a side view thereof. This automatic hardness tester includes a well-known automatic hardness tester main body 20, a stage 22 on which the test piece 10 can be placed and moved in the XYZ directions, a camera 24 for imaging the measurement surface of the test piece 10 at various magnifications, A computer 26 for storing an image captured by the digital camera 24 as digital information, and a monitor 2 for displaying the captured image
8 mainly.

The computer 26 is capable of storing an inspection position instructed / input on an image on a monitor 28 by an operator, and instructing the stage 22 and the automatic hardness meter main body 20 to measure hardness.

The inspection result by the automatic hardness tester is
The chart printed with 0 allows the measured parts to be listed during the measurement.

The size of the indentation can be confirmed on the indentation monitor 32.

Further, the automatic hardness tester has a function of re-measuring each indentation after the measurement is completed.
By inputting an appropriate inspection position number, the stage 22 is automatically driven, an impression at the inspection position is displayed on the monitor 32, and automatic or manual re-measurement is possible.

FIG. 6 shows the procedure for measuring the hardness of a welded section test piece using the automatic hardness tester. An example of determination and registration of the inspection position will be described with reference to FIG.

First, at step 100, N test pieces 10 are placed and set on the stage 22, and the number N is registered.

Next, according to steps 102 to 108,
A measurement pattern indicating the arrangement of the inspection positions is registered for each test piece. 7 to 9 show examples of the measurement pattern. FIG. 7 shows an example in which inspection is performed at a measurement pitch p = 2 mm along a distance L1 = 2 mm from the contour CT. FIG.
Along the position of distance L1 = 2 mm from the contour CT and the center position of the thickness, 5 points in the molten metal portion 12 and the heat-affected portion 14
This is an example in which two inspection positions and three inspection positions in the base metal 16 are arranged. FIG. 9 shows the inspection positions of one point in the molten metal part 12 and two points in the heat-affected zone 14 along a position at a distance L1 = 2 mm from the contour CT. The closest contact point of the molten metal portion in the affected portion 14 is an example in which the inspection positions are arranged at a position at a distance L2 = 0.5 mm from the boundary with the molten metal portion 12.

As described above, the measurement pattern indicating the arrangement of the inspection positions usually includes the distance L1 between the virtual line V and the contour CT (FIGS. 7, 8 and 9) and the measurement pitch p (FIG. 7) on the virtual line V. ), The number of points in the metal structure (FIG. 8), and the attribute of the inspection position expressed by the distance L2 (FIG. 9) from the metal structure boundary. In particular, the distance between the virtual line V and the contour CT L1
Is used for all measurement patterns. When the number of inspection positions is small as shown in FIG. 9, the impression that the inspection positions are arranged on one line becomes sparse. However, according to the present invention, even if only one inspection position, the contour CT is constant from the contour CT. A virtual line V at a distance of is set. For example, at the thickness center position in FIG. 9, there are only two inspection positions on one virtual line V.

In contrast to the above-described registration of the measurement pattern, since the actual contour CT of the test piece and the shape of the metallographic boundary differ from one test piece to another, to register the inspection position on the test piece as XY coordinates, Teaching is performed according to steps 110 to 128.

That is, first, in step 120, the stage 22
By appropriately moving one of the test pieces 10 for which the inspection position is to be registered under the camera 24 by remote control in the X and Y directions,
A photographed image of the test piece 10 is displayed on the monitor 28, and further,
By moving the stage 22 in the Z direction, focusing is performed on the surface of the test piece with accuracy appropriate for indentation measurement. At this point, the relationship between the entire image and the XY coordinates is registered in the computer 26 as digital information.

The subsequent steps will be described with reference to FIGS. 10 to 13, which are schematic diagrams of test piece images during registration work. First, in step 122, the contour shape of the test piece 10 is registered. In the present embodiment, since the welded section of the pipe-shaped product is assumed, the contour is registered as an approximate GC in which the contour is approximated as an arc. More specifically, as shown in FIG. 10, by operating an appropriate input device and inputting three points PT on an arc near each contour CT, the computer 26 is automatically calculated as shown in FIG. The arc that has been made is roughly G
C, and the outline GC is registered in the computer 26.

Next, at step 124, step 1
Distance L1 between virtual line V and contour CT registered at 06
Is replaced with the distance between the outline GC and the contour CT, the virtual line V is displayed on the image of the monitor 28, and the coordinates of the virtual line V are registered in the computer 26. The form of the contour CT may be devised each time depending on the form of the test piece 10, and the registration method may be a method such as image processing.

Next, at step 126, for example, as shown in FIG.
The intersection CR of the virtual line V and the boundary of the metal structure determined by the method described in 3739 is input.

Then, in step 128, the inspection position x is automatically calculated based on the measurement pitch p on the virtual line V, the distance L2 from the metallographic structure boundary, the number of points in the metallographic structure, etc., which were previously registered in step 106. The coordinates of the inspection position are registered in the computer 26 at the same time as being displayed in the image on the monitor 28 as shown in FIG.

The setting of the boundary position is free, and the embossing point pattern can be changed by the setting even on the same tissue.

Next, according to steps 130 to 136,
Automatic measurement using the registered inspection position x and re-measurement as necessary are performed.

In this embodiment, among the attributes of the inspection position,
Register the distance from the contour and the number of measurement points in the tissue area that do not change due to the individuality of the test piece as a measurement pattern, and teach the contour or tissue area that changes with the individuality of the test piece for each individual test piece on the monitor. As a result, the inspection position can be determined efficiently. Note that the specific registration method is not limited to this.

In the above description, the present invention has been applied to an arc-shaped test piece. However, the shape of the target test piece is not limited to this, and may be a linear shape such as a rectangle or another shape. It doesn't matter.

The measuring device for determining the inspection position according to the present invention is not limited to a hardness tester, and may be used for automatically inspecting and analyzing characteristics other than hardness, components of tissue, and the like. It is clear that the present invention can be similarly applied to determination of an inspection position in a visual inspection device or an analysis device.

[0032]

According to the present invention, in a microscopic inspection apparatus such as an automatic hardness tester or an automatic microhardness tester, a large number of inspection positions such as a cross section of a welded portion can be efficiently used and a large number of test pieces can be measured. Can be determined and registered, and significant labor saving and elimination of individual differences can be achieved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an inspection position in a section of a welded portion of a UOE pipe.

FIG. 2 is a sectional view for explaining an inspection position determination procedure according to the present invention.

FIG. 3 is an enlarged view of a main part of FIG. 2;

FIG. 4 is a front view including a partial block diagram showing a configuration of an automatic hardness tester to which the inspection position determining method according to the present invention is applied;

FIG. 5 is a side view of the same.

FIG. 6 is a flowchart showing an example of a measurement procedure of an automatic hardness tester employing the inspection position determination method according to the present invention.

FIG. 7 is a sectional view showing an example of a measurement pattern.

FIG. 8 is a sectional view showing another example of the measurement pattern.

FIG. 9 is a sectional view showing still another example of the measurement pattern.

FIG. 10 is a diagram showing an example of a monitor image in which a contour of a test piece is designated during registration work according to the present invention;

FIG. 11 is a diagram showing an example of a monitor image displaying the outline of the outline in the same manner.

FIG. 12 is a diagram showing an example of a monitor image in which an intersection of a virtual line and a boundary between metal structures is input.

FIG. 13 is a diagram showing an example of a monitor image showing a finally determined inspection position.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Test piece 12 ... Molten metal part 14 ... Heat affected zone 16 ... Base metal x ... Inspection position V ... Virtual line GC ... Outline CT ... Contour B ... Boundary CR ... Intersection L1, L2 ... Distance 20 ... Automatic hardness tester Body 22 ... Stage 24 ... Camera 26 ... Computer 28 ... Monitor 32 ... Indentation monitor

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01N 3/00-3/62 G01N 1/28 JICST file (JOIS)

Claims (2)

(57) [Claims] In a method for determining an inspection position of a metal weld cross section test piece based on a relationship between a weld metal structure and a contour of the test piece, an image of the metal weld cross section test piece is taken. And a plurality of points characterizing the contour of the test piece using the captured image.
, A curve representing the contour shape of the test piece is calculated, and a virtual line for arranging and grouping inspection positions at a certain distance from the curve representing the contour shape is determined. A method for determining an inspection position of a cross section of a metal weld, comprising: determining an intersection of a boundary of a structure; and determining an inspection position from a distance along the virtual line from the intersection. 2. The method according to claim 1, wherein the imaginary line is determined based on an outline of a test piece contour approximated by an arc or a straight line.