JPS63308501A - Nondestructive measuring apparatus for depth of cabonization - Google Patents

Abstract

PURPOSE:To make a measuring operation efficient by indicating the depth of carbonization optically for measurer by means of illuminant indicator elements provided for a carbonization probe. CONSTITUTION:Illuminant indicator element 22-24 of a carbonization probe are illuminant with colors discernible for each depth of carbonization, while sound generator elements 25-27 thereof produce sounds different in pitch or loudness therefor. The indicator element 22-24 are fitted to a handle 3 of the probe. When the probe 2 moved along a material 1 to be inspected with the handle 3 gripped, a voltage corresponding to the presence and depth of a carbonized part 10 inside of the material is generated in the probe 2 and sent to a detector element, whereby the depth of carbonization of the part is measured. When a detection signal exceeds a reference level on the occasion, an output signal is delivered from comparators 16-18 in accordance with a low, medium or high level thereof, respectively. Therefore transistors 19-21 are turned ON, and thereby the indicator elements 22-24 are lighted to be illuminant with a color of blue, yellow or red respectively, while the generator elements 25-27 generate a low, medium or high sound respectively. Accordingly, a measurer can determine the depth of carbonization, and thus measurement at a high or distant position can be performed by a one-man operation.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is a non-destructive method for non-destructively measuring carburized parts generated on the inner surface of thalassoking tubes for ethylene production in the petrochemical industry from the outer surface. This relates to a type carburization depth measuring device.

(Prior art) As a cranking tube for ethylene production, which is a reaction tube for recovering ethylene, etc. by thermally decomposing raw material naphtha under high temperature and high pressure, ASTM ■ 40 (0.4% C-
25%Cr-20χNi),)IP45(0,45%
C-25%Cr-35%Ni), or FIP improved material (
HP materials with Mo, W, Nb, etc. added singly or in combination) are used.

When a Thalasso King tube is used for a long period of time, carbon generated by reaction adheres to the inner surface of the tube, and this adhered carbon diffuses into the metal at high temperatures, causing carburization. The carbon that has entered through carburization forms Cr carbide, and when carburization is accelerated, the Cr carbide becomes coarse, resulting in a significant decrease in ductility in a low temperature range (approximately 800° C. or lower). In addition, the coefficient of thermal expansion of the carburized part of the tube is smaller than that of the non-carburized part, so rapid heating and cooling will cause tension and
The generation of compressive stress and the decrease in ductility in the low temperature range may overlap, resulting in failure of the tube.

Therefore, in order to prevent tube destruction and maintain safe and smooth operations, it is necessary to conduct carburization inspections periodically to accurately understand the presence or absence of carburization and its progress. .

As a method for non-destructively measuring the carburized depth, there is a known magnetic measurement method that utilizes changes in the composition of the carburized part, that is, changes in magnetic properties due to Cr deficiency and relative increases in Fe and Ni. There is.

For example, as disclosed in JP-A-61-195351, a carburizing probe containing a permanent magnet and a pole element disposed within the magnetic field is used, and the magnetism of the carburized part generated inside the reaction tube is used. There is a method of measuring carburization depth using Hall electromotive force detected as the magnetic field of a permanent magnet changes.

(Problem to be Solved by the Invention) Conventionally, the detection signal detected by the carburizing probe was amplified in the amplifier section, and then sent to the meter drive section to drive the meter, and the indicated value was read by the deflection of the pointer. It is common that the

Therefore, when moving the carburizing probe along the reaction tube and making measurements at high or far away positions in the reaction tube, there is a need for a measurer to read the reading on the meter and to record the measurement results. This method has the disadvantage that two recorders have to perform the work, and it is not possible to save labor.

In view of these conventional problems, the present invention aims to save labor by optically displaying the carburizing depth to the measurer using a light-emitting display section provided on the carburizing probe. be.

(Means for Solving the Problem) As a means for that purpose, the present invention provides a carburizing probe 2 that detects the carburizing depth inside the specimen 1 as a change in an electric signal, and a reference level for each carburizing depth. Setting sections 13 and 14
．． 15, the detection signal from the carburizing probe 2 and the setting section 13
, 14.15, and outputs an output signal when the detected signal is greater than the reference level; and an output from this comparison unit 16.17.18. The light-emitting display parts 22, 23 are provided with light-emitting display parts 22, 23, and 24 that can be identified for each carburizing depth according to the signal.
．． 24 is provided on the carburizing probe 2.

(Function) During measurement, when the carburized probe 2 is moved along the material 1 to be inspected, if there is a carburized portion 1o in the material 1 to be inspected, the carburized probe 2 outputs a detection signal corresponding to the carburized portion 1o. Then, this detection signal is sent to the reference level a, b in the comparing section 16, 17, 18.
, c, and when it exceeds any of the reference levels a, b, and c, the output of the corresponding comparison section 16, 17, and 18 indicates that the light emitting display section 22 provided in the carburizing probe 2
, 23 and 24 emit light to display the carburization depth to the measurer.

(Example) Hereinafter, the present invention will be described in detail with reference to the illustrated example.
In the figure, 1 is a material to be tested such as a reaction tube, and 2 is a carburized probe, which has a handle 3 and is adapted to be moved along the material 1 to be tested by grasping the handle 3. Carburizing probe 2 is
As shown in FIG. 2, a permanent magnet 5, a first Hall element 6 for measuring the carburized portion, and a second Hall element 7 for compensation are provided in the protective container 4, and a dummy piece 8 is placed on the protective container 4. It is set up. The magnet 5 has a solid rod shape, and a first Hall element 6 and a second Hall element 7 are arranged at right angles to the longitudinal direction of the magnet 5 on both sides of the center between the pair of magnetic poles N-3. arranged symmetrically. The first Hall element 6 is placed on the side of the material to be inspected 1, and the second Hall element 7 is placed on the opposite side. The first Hall element 6 and the second Hall element 7 are in the magnetic field of the magnet 5, and when a current is passed in a direction perpendicular to the lines of magnetic force that cross the plate thickness direction, an electromotive force is generated in a direction perpendicular to the lines of magnetic force and the current. It is configured as follows. The test material 1 has a decarburized layer 9 over the entire outer surface, and a carburized portion 10 is generated on the inner side. The dummy piece 8 has approximately the same magnetic permeability as the portion of the test material 1 other than the carburized portion 10,
It has a decarburized layer 11.

The dummy piece 8 is placed near the second Hall element 7 at a position that is approximately symmetrical to the specimen 1 with respect to the magnet 5, and is attached to the protective container 4. Therefore, due to the presence of the dummy piece 8, the magnetic field on the second Hall element 7 side is
This is approximately equivalent to the magnetic field on the first Hall element 6 side in a portion without 0, and the first Hall element 6 and the second Hall element 7 normally generate approximately the same level of electromotive force.

The first Hall element 6 and the second Hall element 7 are connected in opposite directions so that their electromotive voltages cancel each other out. The protective container 4 is made of non-magnetic material.

12 is a detection section which performs processing such as amplifying the detection signal from the carburizing loop 2. 13, 14, and 15 are setting parts composed of volumes, etc., which set the standard level a for each carburizing depth.
, b, and c are set.

Reference numeral 16.17.18 is a comparison section consisting of an operational amplifier, etc., which compares the detection signal with reference levels a, b, and c set in each setting section 13.14.15, and determines whether the detection signal is higher than the reference level. It is configured to output an output signal when the signal is large. 19, 20, and 21 are transistors, and each comparison section 16
．． It is connected to the output side of 17 and 18, and turns on when there is an output signal. Each transistor 19, 2
0.21 includes a light emitting display section 22.2 such as a light emitting diode.
A parallel circuit of 3.24 and a sound generating section 25, 26, 27 such as a buzzer is connected in series. The light emitting display parts 22, 23, 24 and the sound generating parts 25, 26, 27 are designed to emit light in distinguishable colors for each carburizing depth, or to generate sounds of different heights or sizes. . 28 is a power source. Light emitting display sections 22, 23, 2. i is attached to the handle 3 of the carburizing probe 2, and the Hall element 6,
Lead wires 29 and 30 connected to 7 and the light emitting display section 22
．． Lead wires 31, 32, 33 connected to 23, 24 are passed through holes in the handle 3.

Note that the reference levels a, b, and c are as shown in Fig. 3, and the reference level a is the level when carburization is slightly progressing;
Reference level b indicates a level when carburization has progressed deeply, and reference level C indicates a level when carburization has progressed extremely deeply and the material has deteriorated significantly and requires replacement.

In the above configuration, when measuring the carburized depth of the material 1 to be inspected, the carburized probe 2 is moved along the material 1 to be inspected by holding the handle 3. Then, a voltage is generated in the carburizing probe 2 according to the presence or absence and depth of the carburized portion 10 inside the material 1 to be inspected, and this is sent to the detection section 12 as a detection signal. At this time, the third
When the detection signal shown in the figure appears and exceeds the reference level a, an output signal is output from the comparison section 16, so the transistor 19 is turned on, the light emitting display section 22 lights up and emits blue light, and the sound is generated. The section 25 generates low-pitched audio. Further, when the reference level b is exceeded, the comparing section 17 outputs an output signal, the light emitting display section 23 lights up and emits yellow light, and the sound generating section 26 generates a middle tone. Furthermore, when the reference level C is exceeded, the comparison section 18 outputs an output signal, the light emitting display section 24 lights up and emits red light, and the sound generation section 27 generates a high-pitched tone. Therefore, the measurer can visually determine the depth of carburization based on the color emitted by the light-emitting display units 22, 23, 24, as well as the sound generators 25, 26, 27.
The depth of carburization can be determined based on the presence or absence of a warning sound and low, medium, and high-pitched sounds, and measurements at high and remote locations can be carried out by one person. Furthermore, since the operator can mark the specimen 1 at the site where the light-emitting display sections 22, 23, 24 emit light, the efficiency of the measurement work is greatly improved.

(Experimental example) Next, an experimental example will be shown. Test material 1 is HP tube (0°4
C-25Cr-35Ni-Fe), dimension 122Φ-
It is 8t.

Figure 4 shows the results of measuring the carburization depth of this IIP tube. The carburization depth was determined by macro-etching after breaking the tube.

Next, measurements were performed using the apparatus of the present invention using another tube. The device was set so that it would emit blue light when the indicated value in FIG. 4 was 20 or less, yellow when it was 20 to 70, and red when it was 70 or more.

Then, cutting was performed at the position where each of the light-emitting display parts 22, 23, and 24 emitted light, and the depth of carburization based on the macrostructure was measured, and the following results were obtained. According to this, it was recognized that voice-based determination is effective.

Note that the sound generators 25, 26, and 27 may be omitted. Further, the light-emitting display section may emit blue light in a portion where the carburized portion 10 is not present. The light-emitting display section may be a lamp or the like.

(Effect of the invention) According to the invention, the carburization depth detected by the carburization probe is
Since each carburization depth is displayed to the measurer using a distinguishable light-emitting display, the measurement work can be done more labor-savingly and efficiently compared to conventional meters that read readings. . Furthermore, since the light-emitting display section is provided on the carburized probe, it is sufficient to mark the material to be tested at the position of the carburized probe, and its practical value is extremely large.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a configuration diagram of the device of the present invention, FIG. 2 is a sectional view of a magnetic sensor, FIG. 3 is a diagram showing a detection signal and a reference level, and FIG. 4 is a diagram showing a detection signal and a reference level. FIG. 3 is a diagram showing experimental results. 1... Test material, 2... Carburized probe, 13-15.
...Setting section, 16-18...Comparison section, 22-24...
・Light-emitting display section.

Claims (1)

[Claims] (1) Detection from the carburizing probe 2 that detects the carburizing depth inside the test material 1 as a change in electrical signals, the setting sections 13, 14, 15 that sets the reference level for each carburizing depth, and the carburizing probe 2 Comparing sections 16, 17, 18 which compare the signal with the reference level set in the setting sections 13, 14, 15 and output an output signal when the detected signal is higher than the reference level; , 18, which can be identified for each carburizing depth, and the carburizing probe 2 is provided with the light-emitting indicators 22, 23, 24. Non-destructive carburizing depth measuring device.