JPS6227877Y2 - - Google Patents

Description

[Detailed description of the invention] This invention maintains a constant gap with the surface of a high-temperature steel piece when an electromagnetic ultrasonic generation detector scans the surface of a high-temperature steel piece, and also prevents undulations and irregularities (scale, baldness, etc.). The invention relates to a copying boat that protects electromagnetic ultrasonic generation detectors from mechanical damage and high temperatures caused by

As already proposed by the present inventors (Japanese Patent Application Laid-Open No.
52-123650), there is a technology that applies ultrasonic waves to a measurement object in a non-contact manner to detect internal defects in the object, measure thickness, etc. This technology converts electromagnetic energy into mechanical vibration energy within the target.
Ultrasonic waves can be generated within a target and received without contact, so it can be used for targets where acoustic coupling media cannot be applied as in the case of conventional ultrasonic transmission/reception technology due to the high temperature of the target. It also has the feature of being able to detect the generation of ultrasonic waves.

In recent years, this electromagnetic ultrasonic transmission and reception technology has been applied to defect detection, thickness measurement, material quality determination, etc. of various conductive materials. Since the generation and detection of electromagnetic ultrasonic waves is performed by electromagnetic induction, when electromagnetic ultrasonic waves are used for various measurements, they can in principle be applied without contacting the object to be measured. It is particularly effective to apply to high-temperature steel pieces (for example, slabs, blooms, billets, bars, pipes, etc.).

However, as the distance between the electromagnetic ultrasonic generation detector and the object to be measured increases, the sensitivity of the detection signal decreases, so it is usually necessary to maintain the distance to a few mm or less.

For example, when applying electromagnetic ultrasound to a high-temperature steel slab above 1000°C, the ultrasonic wave is attenuated more during the propagation process within the steel slab compared to a cold slab, so the detection sensitivity of the ultrasonic signal is It is known that there is a significant decrease in Further, the surface properties of such steel pieces (for example, the presence of irregularities, scales, scuff marks, etc.) are usually extremely poor.

Therefore, when using an electromagnetic ultrasonic generation detector for defect detection of high-temperature steel pieces of 1000℃ or higher, the gap between the electromagnetic ultrasonic generation detector and the high-temperature steel pieces should be kept as small as possible, and the surface of the steel pieces should be kept as small as possible. It is necessary to run while following the ups and downs. At this time, it is also necessary to protect the electromagnetic ultrasonic generation detector from mechanical damage that may be caused by the high temperature received from the steel piece and from unevenness, scale, sludge, etc. existing on the surface of the steel piece.

Conventionally, as a method that enables various detection ends equivalent to electromagnetic ultrasonic generation detectors to be held and scanned against a high-temperature steel piece with a minute gap, for example, a fluid such as water or air has been used. There is a method of floating and holding it, a method of using an indirect mechanical holding mechanism as described in Japanese Patent Application No. 51-116608, or a method of using a direct wheel or shoe.

However, when the former is put into practical use, the equipment for supplying water and air tends to be large-scale, which has a practical disadvantage in terms of equipment and supply costs. Furthermore, since the surface quality of high-temperature steel pieces is usually significantly worse than that of product materials, it is often difficult to maintain an appropriate gap and perform scanning using fluid flotation.

In the latter case, the wheel cannot rotate smoothly due to fine scale, scratches, dust, etc. on the surface of the high-temperature steel piece, or seizure due to high temperature, or the wheel becomes unusable due to mechanical damage or wear. There are many.

The present invention is to manufacture a copying boat with a simple structure and low cost using a direct contact method against a high-temperature steel piece, and by storing an electromagnetic ultrasonic generation detector in this copying boat, it can be held at a minute constant interval. Moreover, it is capable of scanning. Furthermore, it is possible to overcome the mechanical failure caused by the poor surface properties of the steel piece as described above. Hereinafter, this will be explained in detail using examples.

FIG. 1 shows an embodiment of the present invention, that is, a schematic diagram of a copying boat 1 housing an electromagnetic ultrasonic generation detector and its holding mechanism, and shows an internal defect 2' of a hot slab 2 after blooming. The flaw detection status is also shown. The electromagnetic ultrasonic generation detector 3 housed in the copying boat 1 is slightly pressed down toward the storage step 6 of the copying boat 1 by a presser spring 5 so as to maintain a gap 4 between it and the surface of the high-temperature slab 2. This also prevents the electromagnetic ultrasonic wave generator 3 from fluttering during scanning. The gap 4 between the electromagnetic ultrasonic generation detector 3 and the slab surface can be set appropriately by replacing the gap adjustment spacer 7. The entire copying boat is held by a boat holding hanging bracket 8, and in order to copy large undulations and irregularities on the slab 2, a shaft joint 9 attached parallel to the scanning direction of the copying boat is used. By moving the rolling and sliding convex part 10 up and down the sliding slit 11 attached to the hanging bracket 8, the sliding convex part 9 can move up and down the sliding slit 11 attached to the hanging metal fitting 8, and the sliding convex part 9 can move up and down against small undulations and irregularities on the slab surface. It is possible to imitate by curvature. The hanging fitting 8 is connected to the flange 12 via the shaft joint 9, and the flange 12 is connected to the copying boat 1.
connected to a support arm 13 for scanning,
The entire support arm 13 is connected to its scanning drive. Incidentally, a discharge slit 14 is attached to the bottom surface of the copying boat 1 for draining the cooling water jetted from the electromagnetic ultrasonic generation detector 3.
This drainage serves to cool the bottom of the copying boat 1.

2a and 2b show schematic diagrams of a front view and a bottom view of the copying boat 1 in which the electromagnetic ultrasonic generation detector 3 is housed. A cooling water jetting slit 15 is attached to the slab facing surface of the electromagnetic ultrasonic generation detector 3, and a magnet 16, an ultrasonic generation coil 17, and a detection coil 18 that constitute the electromagnetic ultrasonic generation detector 3 are attached.
Cooling water is ejected to insulate the slab-facing surface of the protective case 19 from high temperatures. The bottom surface of the copying boat 1, that is, the contact surface with the high-temperature slab 2, has an appropriate curvature at the front, rear, left and right ends to make it easier to follow the undulations and irregularities of the slab. Furthermore, since the bottom surface of the copying boat 1 is considerably worn when scanning the slab surface, a heat-resistant and wear-resistant special alloy layer 20 is thermally sprayed on the bottom surface.

When the electromagnetic ultrasonic generation detector 3 housed in the copying boat 1 was used to detect internal defects 2' in the high-temperature slab 2 of 1000°C or higher immediately after blooming as shown in Fig. 1, electromagnetic and ultrasonic waves were detected. The ultrasonic generation detector 3 was able to perform flaw detection even at high temperatures without suffering any thermal damage. This is because a water film is formed by the cooling water jetted from the electromagnetic ultrasonic generator 3 on the minute gap 4 formed by the copying boat 1 between the electromagnetic ultrasonic generator 3 and the slab surface. It is thought that the high temperature of the slab was able to be insulated. Furthermore, it was possible to make the electromagnetic ultrasonic wave generating detector 3 follow the undulations, irregularities, scales, scratches, etc. on the surface of the high-temperature slab 2 without causing any mechanical damage. At this time, the gap between the electromagnetic ultrasonic generation detector 3 and the high-temperature slab 2 was set and maintained at 1 to 2 mm by the copying boat 1. The amount of cooling water jetted from the electromagnetic ultrasonic generation detector 3 is 3 to 4/mm, and in this case, the temperature of the surface of the electromagnetic ultrasonic generation detector 3 facing the slab is 150° C. or less. Also, the bottom temperature of the boat itself is 30 degrees from the bottom.
The temperature is maintained below approximately 60℃ in the upper mm region. Copy boat 1
The main body is made of cast stainless steel, and the bottom of the boat is made of a special heat-resistant and wear-resistant alloy alloy of Ni-Cr.
-It is thermally sprayed with W-Fe alloy. The hanging fittings 8, etc. of copying boat 1 were made of SUS27 stainless steel.

As described above, if the electromagnetic ultrasonic generation detector 3 is housed in the copying boat according to the present invention and the internal defects 2' of the high temperature slab 2 are detected, the electromagnetic ultrasonic generation detector 3 can be placed against the high temperature slab 2. It has a simple structure and is inexpensive, and it is possible to maintain a certain minute gap and make it conform properly, and there is no practical problem with regard to high temperature and mechanical damage from the slab 2. A copy boat 1 can be provided.

In the embodiment, a case has been described in which the copying boat 1 is used to detect internal defects in a high-temperature slab 2, but it can also be applied to other high-temperature steel pieces, such as blooms, billets, pipes, and bars. Although the shape of the copying boat 1 has been explained using a ship-shaped one, the shape can be changed depending on the object of application, such as round or square. For example, the third
The figure shows a case where rollers 22 are attached to the front and rear ends of a round copying boat 21. These rollers are effective in reducing friction between the bottom of the boat and the surface of the slab during scanning of the copying boat, and also provide good scanning performance for unevenness, scale, etc.

There are no particular limitations on the method of holding the copy boat, but the present invention is effective in any case.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway side view schematically showing a copying boat housing an electromagnetic ultrasonic generation detector and its holding mechanism, which is an embodiment of the present invention;
Figures a and 2b are a sectional view and a bottom view of a copying boat housing an electromagnetic ultrasonic generation detector. FIG. 3 is a side view showing another embodiment of the present invention. 1: Copying boat, 2: High temperature slab, 3: Electromagnetic ultrasonic generation detector, 4: Gap, 5: Presser spring,
6: Step, 7: Spacer, 8: Hanging bracket, 9: Shaft joint, 10: Convex part for slide, 11: Slit for slide, 12: Flange, 13: Support arm, 14: Slit for discharge, 15: Cooling water Ejection slit, 16: magnet, 17: ultrasonic generation coil, 18: detection coil, 19: protective case,
20: Special alloy layer, 21: Round copying boat, 2
2: Coro.

Claims (1)

[Scope of utility model registration request] It has a step 6 inside, and the electromagnetic ultrasonic generation detector 3 is housed in the surface of the subject 2 at a predetermined interval so as to fit and press into the step 6 by means of a pressing spring 5. Heat-resistant alloy metal 20 on the bottom
Further, it is provided with a discharge slit 14 for guiding and discharging the cooling water from the detector 3, and is configured to be swingably suspended from the support arm 13 by the rolling slide protrusion 10. A copying boat that houses a supermagnetic ultrasonic generation detector for inspecting high-temperature materials.