JPS60256050A - Non-destructive inspection apparatus - Google Patents

Abstract

PURPOSE:To inspect the quality of an object to be inspected with high accuracy, by providing a means wherein the object to be inspected is vibrated by a hammer and the change in the vibration generated in the object to be inspected is detected at this time and quantitatively shown through the analysis of a wave form. CONSTITUTION:An object 11 to be inspected such as a hardened build-up roll is striken and vibrated under definite load by a hammer 14 and the vibration wave generated at this time is detected by an external sensor 15a such as a microphone while the detection signal from the sensor 15a is amplified by an amplifier 16 to be inputted to a wave form analytical apparatus 17. In this wave form analytical apparatus 17, the detection signal from the sensor 15a receives operation treatment using a preset parameter and the wave form corresponding to the vibration wave is displayed on a display apparatus 19 and the recording of a determined value is performed by a hard copy apparatus 20. By monitoring thus displayed vibration wave form and comparing the same with a comparison reference value, the quality of the object 11 to be inspected can be judged.

Description

[Detailed description of the invention] It was designed to enable destructive inspection.

A hardfacing roll 1 as shown in FIGS. 1 and 2 is used as a mill roll for coal crushing, which is one type of boiler combustion equipment. This hardfacing roll 1 is composed of a casting roll base material 2 and a hardfacing welded part 3. In the hardfacing roll 1 of B, the hardfacing welding part 3 is connected to the casting roll base material 2.
If the weld is not reliably welded, a part of the hardfacing weld 3 will peel off.

Therefore, in order to inspect the quality or durability of the hardfacing roll 1, shore hardness has conventionally been measured. To measure job hardness, the hardness at each measurement point 5 on the surface of the hardfacing weld 3 was measured using a Syria hardness meter 4. If the job hardness is above a certain value, it is judged to be of good quality, and on the other hand, if the serial hardness is below a certain value, peeling occurs in the hardfacing weld 3. It was determined that the

By the way, when the hardfacing roll 1 was cut and the cross section of the overlay welding part 3 was inspected, it was found that the quality of the overlay welding part 3 and the shore hardness measurement results sometimes did not match. . Therefore, there is a safety problem in inspecting the quality of overlay welds based on Shore hardness.

Currently, it has been confirmed that a large number of weld cracks occur in overlay welds, and if a defective hardened overlay roll is hit with a hammer, etc., and the reflected sound is compared, it is confirmed that it is a good product. It was found that the sound was different from the defective product. Therefore, we focused on the difference in the sound produced by hammers, that is, the difference in the way vibration is attenuated in the overlay weld, and we thought that if we quantitatively examine the vibration waveform, it would be possible to inspect the quality of the overlay weld. It's arrived.

In view of the above-mentioned circumstances, an object of the present invention is to provide a non-destructive inspection device that can improve the quality inspection accuracy of hardfacing rolls and strictly control the quality of rolls at the shipping stage.

The present invention achieves the above object by vibrating an object to be inspected such as a hardfacing roll with a hammer, detecting changes in the vibration waveform generated at this time with a sensor such as a microphone or an acceleration sensor, and analyzing the detected signal by waveform analysis. The feature is that the device performs arithmetic processing to quantitatively indicate waveform changes.

According to the present invention, the following effects are achieved.

(il) The overall soundness of hardfacing welds with many weld cracks can be inspected and evaluated.

(11) Since destructive inspection is performed by calculating the attenuation due to hammer vibration, necessary parameters can be quantitatively evaluated.

(iii) The time required for inspection is reduced.

(ivl) Inspection accuracy is significantly improved compared to conventional methods.

The present invention is applicable not only to the inspection of hardfacing rolls, but also to the welding integrity inspection of various welded parts, crack inspection of concrete,
It can be applied to various qualitative or quantitative nondestructive tests, such as inspecting for cracks in rails, and inspecting looseness and defects in tightened parts of rivets and nuts.

Embodiments of the present invention will be described in detail below based on the drawings.

3 and 4 show an embodiment of the invention.

As shown in both figures, the hardfacing roll 11 has a vibration-proofing rubber 12.
It is placed on the roll support material 13 via. The hardfacing roll 11 is struck and vibrated with a constant load by a hammer] 4,
In the example shown in Fig. 3, the vibration wave generated at this time is 1/7
It is detected by the external sensor 15a, which is 0 phon, and by the internal sensor 15b, which is an acceleration sensor fixed to the inner circumferential surface of the hardfacing roll 11, as shown in FIG. Detection signals from the sensors 15 a and 15 b are amplified by an amplifier 16 and input to a waveform analyzer 17 . Parameters necessary for waveform analysis are preset in this waveform analysis device 17 using calculation keys 18 . Therefore, the waveform analysis device 17 performs arithmetic processing on the detection signals from the sensors 15a and 15b using preset parameters, displays the waveform corresponding to the vibration wave on the display device 19, and records quantitative values on the hard copy device 20. I do. The quality of the hardfacing roll 11 can be determined by monitoring the displayed vibration waveform and comparing it with a comparison reference value.

Note that as the quantitative value, for example, the attenuation rate, that is, the amount of change in sound pressure per time is used. In addition, as reference values for comparison, basic data collected by fabricating overlay rolls with various quality properties by overlay welding of pipes with the same shape and dimensions and conducting sonic tests using them as test materials, as well as the implementation of in-machine overlay rolls. A judgment table that includes analysis of test data is used. Note that FIG. 5 shows the flow of operation.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are explanatory diagrams for explaining the conventional technology,
3 and 4 show the first and second embodiments of the present invention, respectively.
FIG. 5 is a flowchart showing the operating procedure of this embodiment. In the drawing, 11 is a hardfacing roll, 14 is a hammer, 1'5a and 15b are sensors, 17 is a waveform analysis device, 19 is a display device, and 20 is a hard copy device. 1 ['' Figure 3 7 8 Figure 4 Figure 5

Claims (1)

[Claims] A hammer that vibrates the object to be inspected, a sensor that detects vibration changes that occur in the object to be inspected due to the vibration of the hammer,
A non-destructive inspection device characterized by comprising a processing device that analyzes the waveform of the vibration change detected by the sensor and quantitatively shows the vibration change.