JP6596459B2 - Apparatus and method for estimating boron concentration of alloy iron - Google Patents

Description

  The present invention relates to an estimation device and an estimation method for estimating the boron concentration of alloy iron.

  Various techniques for measuring the concentration of boron remaining on a steel sheet have been proposed. For example, Patent Document 1 includes a neutron irradiator having a neutron source and a flat reflector base made of a neutron reflector, on which a stainless steel plate to be processed is placed, and is emitted from the neutron source. A measuring device that measures the content of neutron absorbing substances such as boron in a stainless steel plate by counting the number of thermal neutrons that pass through the stainless steel plate among the thermal neutrons that are scattered and decelerated by the reflector base It is disclosed. In the case of this measuring apparatus, since the stainless steel plate can be held between the neutron irradiator and the reflector base without any gap, the boron content in the stainless steel plate can be accurately measured.

JP 2000-193610 A

  By the way, when a lot of boron is contained in the iron alloy, which is an auxiliary raw material of steel, it may affect the performance of the steel produced using it, so not only the boron concentration of the steel after production. The need to control the boron concentration of the alloy iron is also recognized. However, in the case of alloy iron, it is rare to have a plate-like form like a steel plate, and since it usually has various shapes, in the conventional measuring apparatus described above, a neutron irradiator, a reflector base, Therefore, it is difficult to accurately measure it.

  This invention is made | formed in view of such a situation, The main objective is to provide the estimation apparatus and estimation method which can estimate the boron concentration of alloy iron simply.

  In consideration of the various shapes of the iron alloy, the present inventors measured the boron concentration after pulverizing the iron alloy and filling it into a container of a predetermined shape. Although it examined, it considered that it was not preferable when cost etc. were considered, and invented the following.

  An apparatus for estimating the boron concentration of iron alloy according to one aspect of the present invention includes a neutron source that emits fast neutrons, a moderator for converting fast neutrons emitted by the neutron source into thermal neutrons, an alloy A storage case for storing iron, a storage case from which thermal neutrons converted by the moderator are radiated, a counting means for counting the number of thermal neutrons passing through the storage space, and a counting by the counting means Specific means for identifying the weight of boron in the accommodation space based on the number of thermal neutrons that have been determined and the relationship between the predetermined number of thermal neutrons passing through the accommodation space and the weight of boron in the accommodation space And estimating means for estimating the boron concentration of the alloy iron based on the weight of boron in the accommodation space specified by the specifying means and the weight of the alloy iron.

  In the above aspect, the alloy iron is preferably an alloy iron in a shipping state.

  Moreover, the said aspect WHEREIN: It is preferable that the said storage space has comprised the rectangular parallelepiped shape.

  The method for estimating the boron concentration of alloy iron according to one aspect of the present invention includes a step of radiating thermal neutrons to a storage case having a storage space for storing the alloy iron, and heat that has passed through the storage space. Based on the step of counting the number of neutrons, the counted number of thermal neutrons, and the predetermined number of thermal neutrons passing through the accommodation space and the weight of boron in the accommodation space, the accommodation space And determining the boron concentration of the alloy iron based on the specified boron weight in the containing space and the weight of the alloy iron.

  According to the apparatus and method for estimating boron concentration of alloy iron according to the present invention, the boron concentration of alloy iron can be easily estimated.

The block diagram which shows the structure of the boron concentration estimation apparatus which concerns on embodiment. Sectional drawing which shows the structure of the concentration estimation apparatus main-body part with which the boron concentration estimation apparatus which concerns on embodiment is provided. The graph which shows the relationship between the count value of a thermal neutron, and the boron weight in accommodation space. The flowchart which shows the procedure of a boron concentration estimation process.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, each embodiment shown below illustrates the method and apparatus for actualizing the technical idea of this invention, Comprising: The technical idea of this invention is not necessarily limited to the following. Absent. The technical idea of the present invention can be variously modified within the technical scope described in the claims.

(Configuration of boron concentration estimation device)
FIG. 1 is a block diagram showing a configuration of a boron concentration estimation apparatus according to the present embodiment. As shown in FIG. 1, a boron concentration estimation device (hereinafter referred to as “concentration estimation device”) 1 includes a concentration estimation device main body 1a and boron of iron alloy based on information input from the concentration estimation device main body 1a. And a control device 1b for estimating the concentration. The control device 1b includes a counting unit 50, a calculation unit 60, a storage unit 70, and a display unit 80. For example, a personal computer can be used as the control device 1b.

  The concentration estimation apparatus main body 1a includes a neutron irradiator 10 for irradiating thermal neutrons to a boron concentration estimation processing target, a storage case 20 that stores the alloy iron F that is a processing target, and a storage case 20 A neutron detector 30 for detecting the passing thermal neutrons and a weighing unit 40 for measuring the weight of the alloy iron F accommodated in the accommodation case 20 are provided. Here, the storage case 20 is disposed between the neutron irradiator 10 and the neutron detector 30 and is provided in contact with the neutron irradiator 10 and the neutron detector 30 without a gap.

Details of the components of the concentration estimation apparatus main body 1a will be described below. FIG. 2 is a cross-sectional view showing the configuration of the concentration estimation apparatus main body 1a.
The neutron irradiator 10 includes a housing 11, a neutron beam source 12 provided in the housing 11, and a moderator 13 for decelerating fast neutrons and converting them into thermal neutrons. The housing 11 has a hollow rectangular parallelepiped shape in which the surface on the housing case 20 side is opened, and has a rectangular parallelepiped housing space inside. The housing 11 is composed of a plate-like member capable of shielding neutrons such as a cadmium plate. Thereby, it can prevent that a neutron leaks outside from said open surface other than.

  The neutron source 12 is a source that radiates fast neutrons in all directions, and is composed of, for example, a californium 252 (Cf-252) neutron sealed source. This neutron beam source 12 is attached to the inner wall of the wall on the opposite side of the housing 11 from the side on which the housing case 20 is provided. Moreover, the moderator 13 is comprised with the polyethylene board, and is provided in contact with the storage case 20 so that the open surface of the housing | casing 11 may be covered.

  The housing case 20 includes a housing 21 made of a plate member made of aluminum. The casing 21 has a hollow rectangular parallelepiped shape with the upper surface open, and has a rectangular parallelepiped-shaped accommodation space 21a therein. Alloy iron F, which is a processing target for estimating the boron concentration, is inserted from the open surface of the casing 21 and accommodated in the accommodating space 21a. Examples of the alloy iron F to be processed in the present embodiment include silicon manganese (SiMn). However, other alloy irons such as ferrosilicon (FeSi) and ferromanganese (FeMn) may be treated.

  In the manufacturing process, the iron alloy is cooled in the form of a plate having a thickness of about several centimeters, and then crushed by a crusher to form a lump having a particle size of about several tens of millimeters before being shipped. There are various sizes and shapes. For example, there are particles having a particle diameter exceeding 100 mm and those having a particle diameter of approximately 20 mm. The accommodation space 21a of the accommodation case 20 has a size and shape that can accommodate most of the alloy irons having various sizes and shapes. Thereby, it becomes possible to make many alloy irons to be processed as shipped.

  The housing case 20 described above is connected to a weighing device 40 as shown in FIG. The weighing device 40 measures the weight of the alloyed iron F when the alloyed iron F is accommodated in the accommodating space 21a of the accommodating case 20. The weighing instrument 40 is also connected to the calculation unit 60 of the control device 1b, and outputs a signal indicating the measurement result of the weight of the alloy iron F to the calculation unit 60.

  The neutron detector 30 includes a housing 31 and a thermal neutron detector tube 32 provided in the housing 31. The casing 31 has a hollow rectangular parallelepiped shape, and has a rectangular parallelepiped-shaped accommodation space therein. For example, a He3 detector tube can be used as the thermal neutron detector tube 32 mounted in the accommodation space. The thermal neutron detector tube 32 detects thermal neutrons that have passed through the housing case 20. As shown in FIG. 1, the neutron detector 30 is connected to the counting unit 50 of the control device 1 b and outputs a signal indicating the thermal neutron detection result by the thermal neutron detection tube 32 to the counting unit 50.

  The counting unit 50 counts the number of thermal neutrons based on the signal input from the neutron detector 30 and outputs a signal indicating the counting result to the calculation unit 60. The calculation unit 60 estimates the boron concentration of the alloy iron F using the signal input from the counting unit 50, the computer program and various data stored in the storage unit 70, as will be described later, and the estimation result. Is output to the display unit 80. The display unit 80 displays information indicating the estimation result on the screen.

  Fast neutrons radiated from the neutron beam source 12 included in the neutron irradiator 10 propagate through the casing 11 of the neutron irradiator 10, collide with the moderator 13 and decelerate. By repeating this collision, fast neutrons are converted into thermal neutrons. The thermal neutrons generated in this way enter the storage case 20 and propagate in the storage space 21a of the storage case 20. Thereafter, the thermal neutrons that have passed through the housing case 20 are detected by the neutron detector 30, and the number thereof is counted by the counting unit 50.

  In the accommodation space 21a of the accommodation case 20, when boron having a remarkably large neutron absorption cross-section compared to other elements is present, most of the thermal neutrons are absorbed by the boron, and thus pass through the accommodation space 21a. The number of thermal neutrons decreases. In this embodiment, since the alloy iron F is accommodated in the accommodating space 21a, most of the thermal neutrons are absorbed by the boron contained in the alloy iron F. Even if elements other than boron are present in the accommodation space 21a of the accommodation case 20 as elements that absorb thermal neutrons, the number of thermal neutrons absorbed by the elements is extremely small. Therefore, it can be said that the decrease in the number of thermal neutrons is dominated by boron existing in the accommodation space 21a. Therefore, it is considered that a certain relationship is established between the number of thermal neutrons that have passed through the storage space 21a and the weight of boron present in the storage space 21a of the storage case 20. As will be described later, in this embodiment, the boron concentration of the alloy iron F is estimated using this relationship.

The relationship (hereinafter referred to as a calibration curve) between the number of thermal neutrons that have passed through the housing case 20 and the amount of boron present in the housing space 21a of the housing case 20 is obtained as follows.
First, a plurality of samples of alloy iron F are prepared, and the following processing is performed for each of these samples.
(1) The boron concentration of each sample is measured by ICP emission spectroscopy.
(2) The weight of boron contained in the sample is measured based on the measured boron concentration and the weight of the sample.
(3) The sample is accommodated in the accommodating space 21 a of the accommodating case 20.
(4) Fast neutrons are emitted from the neutron beam source 12, converted into thermal neutrons by the moderator 13, and incident on the housing case 20.
(5) Thermal neutrons that have passed through the accommodation space 21a are detected by the neutron detector 30, and the number of thermal neutrons is counted by the counting unit 50 based on the detection result.
A calibration curve is obtained by plotting the results of (2) and (5) above in a two-dimensional space. FIG. 3 is a graph showing an example of the calibration curve. In this graph, the vertical axis represents the weight (mg) of boron in the accommodation space 21a, and the horizontal axis represents the thermal neutron count value (1,000 pieces / minute). Here, it is assumed that the weight of boron contained in the alloy iron accommodated in the accommodation space 21a matches the weight of boron in the accommodation space 21a. Data indicating such a calibration curve is stored in the storage unit 70 of the control device 1b and is referred to in the boron concentration estimation process described later.

(Operation of concentration estimation device)
Next, the operation of the concentration estimation apparatus 1 configured as described above will be described with reference to a flowchart.
FIG. 4 is a flowchart showing a procedure of boron concentration estimation processing executed by the concentration estimation apparatus of the present embodiment. First, alloy iron F in a shipping state is prepared as a processing target, and this is accommodated in the accommodation space 21 a of the accommodation case 20. Thereafter, the weight W of the alloy iron F is measured by the weighing instrument 40 (S101). A signal indicating the weight W obtained as a result is output from the weigher 40 to the calculation unit 60.

  Next, fast neutrons are emitted from the neutron source 12 (S102). A part of the fast neutrons thus radiated collides with the moderator 13 and decelerates, and is converted into thermal neutrons. A part of the thermal neutron collides with an element present in the accommodation space 21a and is absorbed when passing through the accommodation space 21a of the accommodation case 20. As described above, since boron has a much larger neutron absorption cross section than other elements, most of the thermal neutrons absorbed by the elements in the accommodation space 21a collide with the boron and are absorbed. . On the other hand, thermal neutrons that have passed through the accommodation space 21a without being absorbed by the element are detected by the neutron detector 30 (S103).

  The above-described detection of thermal neutrons is performed for a predetermined time (for example, 1 minute), and a signal indicating the detection result is output from the neutron detector 30 to the counting unit 50. The counting unit 50 counts the number N of thermal neutrons that have passed through the accommodation space 21a of the accommodation case 20 based on the input signal (S104), and outputs a signal indicating the counting result to the calculation unit 60.

  The computing unit 60 acquires the number N of thermal neutrons that have passed through the accommodation space 21 a of the accommodation case 20 based on the signal input from the counting unit 50, and applies this to the calibration curve stored in the storage unit 70. Thus, the boron weight Wb in the accommodation space 21a is specified (S105).

Next, the calculation unit 60 acquires the weight W of the alloy iron in the accommodation space 21a based on the signal input from the weighing instrument 40, and calculates the weight W and the boron weight Wb obtained in S105. Using the following formula 1, the boron concentration of the alloy iron is estimated (S106).
Boron concentration (ppm) of alloy iron = Wb / W ... Formula 1
The boron concentration of the alloy iron estimated in this way is displayed on the screen of the display unit 80 (S107).

  As described above, in the case of the present embodiment, the alloy iron is accommodated in the accommodating space 21a of the accommodating case 20, and the boron concentration of the alloy iron is estimated based on the number of thermal neutrons that have passed through the accommodating space 21a. is doing. For this reason, even if the size and shape of the iron alloy varies, the boron concentration can be estimated as long as it falls within the accommodation space 21a. Accordingly, since the iron alloy can be processed as it is in the shipping state, the trouble of pulverizing the powder into powder is not required, and the boron concentration can be measured efficiently. In the case of alloyed iron, since the boron concentration tends to change continuously in one tapping in an electric furnace, for example, the boron concentration obtained near the start of tapping and that obtained near the end of tapping There may be significant differences in For this reason, it is necessary to estimate the boron concentration of a plurality of alloy irons obtained at different timings, and take measures such as taking the average value to obtain the boron concentration of one lot of alloy iron. Therefore, a great merit is recognized in that the boron concentration can be estimated efficiently as in the present embodiment.

(Other embodiments)
In the above-described embodiment, the storage space 21a of the storage case 20 has a rectangular parallelepiped shape. However, the present invention is not limited to this, and any other alloy iron that can be processed can be stored. It may be a shape. However, in order to reduce the estimation error, it is preferable that the gap is as small as possible when the alloy iron to be processed is accommodated. In consideration of the fact that the alloy iron in a shipping state is a plate-shaped member having a thickness of about several centimeters, the accommodating space 21a has a rectangular parallelepiped shape having a width slightly larger than the several centimeters. It is preferable. Note that, even when the size of the alloy iron F to be processed is small, the gap may be relatively large, so that the estimation error may be large. In that case, when a plurality of alloy irons F can be accommodated in the accommodation space 21a of the accommodation case 20, it is preferable to accommodate the plurality of alloy irons F.

  Further, in the above-described embodiment, the alloy iron in a shipping state is used as a processing target, but the present invention is not limited to this, and the alloy iron that can be accommodated in the accommodating space 21a of the accommodating case 20 is used. Others are acceptable. For example, a plate-like object before being crushed by a crusher in the manufacturing process may be a processing target, or a processed alloy iron in a shipped state may be a processing target.

  Note that when the alloy iron F to be processed contains a large amount of moisture, the estimation error may increase. Therefore, it is possible to correct the estimation result by using a correction coefficient determined according to the amount of water contained in the alloy iron F, or to prepare a different calibration curve according to the amount of water and perform an estimation process. You may make it perform.

  The apparatus and method for estimating the boron concentration of the alloy iron of the present invention are useful as an apparatus and method for estimating the boron concentration of the alloy iron in the shipping state, respectively.

DESCRIPTION OF SYMBOLS 1 Boron concentration estimation apparatus 1a Concentration estimation apparatus main-body part 1b Control apparatus 10 Neutron irradiator 11 Case 12 Neutron radiation source 13 Moderator 20 Accommodation case 21 Case 21a Accommodation space 30 Neutron detector 31 Case 32 Thermal neutron detection tube 40 Weighing instrument 50 Counting unit 60 Calculation unit 70 Storage unit 80 Display unit

Claims (4)

A neutron source emitting fast neutrons;
A moderator for converting fast neutrons emitted by the neutron source into thermal neutrons;
A housing case for housing the alloy iron, and a housing case from which thermal neutrons converted by the moderator are radiated;
Counting means for counting the number of thermal neutrons that have passed through the accommodation space;
Based on the number of thermal neutrons counted by the counting means and the relationship between the predetermined number of thermal neutrons passing through the accommodation space and the weight of boron in the accommodation space, the weight of boron in the accommodation space Identifying means for identifying
An estimation device for boron concentration of alloy iron, comprising: estimation means for estimating the boron concentration of the alloy iron based on the weight of boron in the housing space specified by the specification means and the weight of the alloy iron. The alloy iron is an alloy iron in a shipping state.
The estimation apparatus of the boron concentration of the alloy iron of Claim 1. The accommodation space has a rectangular parallelepiped shape,
The estimation apparatus of the boron concentration of the alloy iron of Claim 2. Radiating thermal neutrons to a storage case having a storage space for storing alloy iron;
Counting the number of thermal neutrons that have passed through the containment space;
Identifying the boron weight in the accommodation space based on the number of thermal neutrons counted and the relationship between the predetermined number of thermal neutrons passing through the accommodation space and the boron weight in the accommodation space; ,
Estimating the boron concentration of the alloy iron based on the identified boron weight in the accommodation space and the weight of the alloy iron.

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