EP0308888A2
Expired / Lapsed
EP
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Method and apparatus for detecting embrittlement of a measuring object
Assignee: Hitachi Ltd
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Filing: 1988-09-21
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Granted: —
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Expires: 2008-09-21
Abstract
Abstract On the basis of a finding that a magnetic hysteresis of a metal material, among magnetization characteristics changing with secular degradation of the metal material, shows a clear correspondence with the degree of degradation of the metal material, a change in such a magnetization characteristic is measured to estimate the degree of secular degradation of the metal material. In a typical embodiment, a superconducting quantum interference device (33; 340) is used to detect the magnetization characteristic of a measuring object (1; 11). According to the present invention, the degree of embrittlement of a metal material used in an environment of high temperatures can be quickly detected in a non-destructive fashion so that the danger of brittle fracture of the metal material can be reliably prevented.
Inventors
- 👤 Masahiro Otaka
- 👤 Kunio Midorigaoka Danchi D-6 Enomoto
- 👤 Kunio Hasegawa
- 👤 Makoto Hayashi
- 👤 Tasuku Shimizu
- 👤 Kazuo Takaku
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 10:30
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/72; G01N17/00; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/842; Y10S505/843; Y10S505/845; Y10S505/846
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
158 words
A method of detecting degradation of a measuring object by applying a magnetic field to said measuring object (1), measuring a change in a peculiar magnetization characteristic of said measuring object, and detecting the degree of degradation of said measuring object on the basis of the result of measurement of the change in the magnetization characteristic of said measuring object, said method comprising the steps of previously computing the relation between changes in the magnetization characteristic and degradation of said measuring object, estimating the magnetization characteristic of said measuring object in an unused virgin state on the basis of said relation, measuring the magnetization characteristic of said measuring object during use, computing the change from the estimated magnetization characteristic to the measured magnetization characteristic, and comparing the computed change in the magnetization characteristic with said relation between the magnetization characteristic and the degradation to decide the degree of degradation of said measuring object at the time of measurement.
Claim 2
Independent Claim
158 words
A method of detecting degradation of a measuring object by applying a magnetic field to said measuring object (1), measuring a change in a peculiar magnetization characteristic of said measuring object, and detecting the degree of degradation of said measuring object on the basis of the result of measurement of the change in the magnetization characteristic of said measuring object, said method comprising the steps of previously computing the relation between changes in the magnetization characteristic and degradation of said measuring object, estimating the magnetization characteristic of said measuring object in an unused virgin state on the basis of said relation, measuring the magnetization characteristic of said measuring object during use, computing the change from the estimated magnetization characteristic to the measured magnetization characteristic, and comparing the computed change in the magnetization characteristic with said relation between the magnetization characteristic and the degradation to decide the degree of degradation of said measuring object at the time of measurement.
Claim 3
Independent Claim
131 words
A method of detecting degradation of a measuring object by applying a magnetic field to said measuring object (1), measuring a change in a peculiar magnetization characteristic of said measuring object and detecting the degree of degradation of said measuring object on the basis of the results of measurement of the change in the magnetic characteristic of said measuring object, said method comprising the steps of previously measuring magnetic hysteresis loops of said measuring object while changing the magnetic field intensity, normalizing the data of said magnetic hysteresis loops, measuring a magnetization characteristic of said measuring object during use, and comparing the data of the measured magnetization characteristic with said data of the normalized magnetization characteristic to estimate the degree of degradation of said measuring object at the time of measurement.
Claim 4
Independent Claim
131 words
A method of detecting degradation of a measuring object by applying a magnetic field to said measuring object (1), measuring a change in a peculiar magnetization characteristic of said measuring object and detecting the degree of degradation of said measuring object on the basis of the results of measurement of the change in the magnetic characteristic of said measuring object, said method comprising the steps of previously measuring magnetic hysteresis loops of said measuring object while changing the magnetic field intensity, normalizing the data of said magnetic hysteresis loops, measuring a magnetization characteristic of said measuring object during use, and comparing the data of the measured magnetization characteristic with said data of the normalized magnetization characteristic to estimate the degree of degradation of said measuring object at the time of measurement.
Claim 5
Dependent Claim
164 words
A degradation detecting apparatus comprising means (2) for applying a magnetic field to a measuring object (1), means (3) for detecting a magnetization characteristic of said measuring object, and an arithmetic processing device deciding the degree of degradation of said measuring object on the basis of a change in said magnetization characteristic of said measuring object due to application of said magnetic field, said arithmetic processing device including a data base (7) storing previously acquired data of the relation between changes in the magnetization characteristic and degradation of said measurement object, a first arithmetic processing part (6) estimating the magnetization characteristic of said measuring object in an as-received material on the basis of the data stored in said data base, and a second arithmetic processing part (6) computing the change from said estimated magnetization characteristic to said detected magnetization characteristic on the basis of the data stored in said data base to generate the degree of degradation of said measuring object as an output.
Claim 6
Dependent Claim
164 words
A degradation detecting apparatus comprising means (2) for applying a magnetic field to a measuring object (1), means (3) for detecting a magnetization characteristic of said measuring object, and an arithmetic processing device deciding the degree of degradation of said measuring object on the basis of a change in said magnetization characteristic of said measuring object due to application of said magnetic field, said arithmetic processing device including a data base (7) storing previously acquired data of the relation between changes in the magnetization characteristic and degradation of said measurement object, a first arithmetic processing part (6) estimating the magnetization characteristic of said measuring object in an as-received material on the basis of the data stored in said data base, and a second arithmetic processing part (6) computing the change from said estimated magnetization characteristic to said detected magnetization characteristic on the basis of the data stored in said data base to generate the degree of degradation of said measuring object as an output.
Claim 7
Dependent Claim
184 words
A degradation detecting apparatus comprising means (2) for applying a magnetic field to a measuring object (1), and a magnetization characteristic measuring device measuring a magnetization characteristic of said measuring object so as to detect the degree of degradation of said measuring object on the basis of a change in said magnetization characteristic of said measuring object due to application of said magnetic field, said magnetization characteristic measuring device including an exciting coil (23) in the form of a superconducting coil, a magnetization sensor (31) disposed at the center of said exciting coil, said sensor being operable at low temperatures, a fluidtight container (110) of a heat insulating material containing the entirety of at least said exciting coil and said magnetization sensor, and a cooling system (400, 410) for cooling the superconducting system, said apparatus further comprising means (5, 6, 7) for previously computing the relation between the magnetization characteristic and degradation of said measuring object and comparing the detected magnetization characteristic of said measuring object with said relation to decide the degree of degradation of said measuring object at the time of detection.
Claim 8
Dependent Claim
184 words
A degradation detecting apparatus comprising means (2) for applying a magnetic field to a measuring object (1), and a magnetization characteristic measuring device measuring a magnetization characteristic of said measuring object so as to detect the degree of degradation of said measuring object on the basis of a change in said magnetization characteristic of said measuring object due to application of said magnetic field, said magnetization characteristic measuring device including an exciting coil (23) in the form of a superconducting coil, a magnetization sensor (31) disposed at the center of said exciting coil, said sensor being operable at low temperatures, a fluidtight container (110) of a heat insulating material containing the entirety of at least said exciting coil and said magnetization sensor, and a cooling system (400, 410) for cooling the superconducting system, said apparatus further comprising means (5, 6, 7) for previously computing the relation between the magnetization characteristic and degradation of said measuring object and comparing the detected magnetization characteristic of said measuring object with said relation to decide the degree of degradation of said measuring object at the time of detection.
Claim 9
Dependent Claim
178 words
A degradation evaluating apparatus comprising means (20, 23) for applying a magnetic field to a sample (11) taken from a part of a measuring object (1), means (310) for detecting a magnetization characteristic of said sample, and an arithmetic processing device deciding the degree of degradation of said sample on the basis of a charge in said magnetization characteristic of said sample due to application of said magnetic field, said arithmetic processing device including a data base (7) storing previously acquired data of the relation between changes in the magnetization characteristic and degradation of said sample, a first arithmetic processing part (6) estimating the magnetization characteristic of said sample on the basis of the data stored in said data base by assuming that said sample is a part of an as-received virgin measuring object, and a second arithmetic processing part (6) computing the change from said estimated magnetization characteristic to said detected magnetization characteristic on the basis of the data stored in said data base to generate the degree of degradation of said measuring object as an output.
Claim 10
Dependent Claim
178 words
A degradation evaluating apparatus comprising means (20, 23) for applying a magnetic field to a sample (11) taken from a part of a measuring object (1), means (310) for detecting a magnetization characteristic of said sample, and an arithmetic processing device deciding the degree of degradation of said sample on the basis of a charge in said magnetization characteristic of said sample due to application of said magnetic field, said arithmetic processing device including a data base (7) storing previously acquired data of the relation between changes in the magnetization characteristic and degradation of said sample, a first arithmetic processing part (6) estimating the magnetization characteristic of said sample on the basis of the data stored in said data base by assuming that said sample is a part of an as-received virgin measuring object, and a second arithmetic processing part (6) computing the change from said estimated magnetization characteristic to said detected magnetization characteristic on the basis of the data stored in said data base to generate the degree of degradation of said measuring object as an output.
Claim 11
Dependent Claim
215 words
A degradation evaluating apparatus comprising means (20, 23) for applying a magnetic field to a sample (11), and a magnetization characteristic measuring device measuring a magnetization characteristic of said sample so as to detect the degree of degradation of said sample on the basis of a change in the magnetization characteristic of said sample due to application of said magnetic field, said magnetization characteristic measuring device including an exciting coil (23) in the form of a superconducting coil, a magnetization sensor (340) in the form of a superconducting quantum interference device having a superconducting pickup coil (330) of differential type disposed at the center of said exciting coil, said superconducting pickup coil of different type defining thereinside a space into which said sample (11) can be inserted from the outside, a fluidtight container (110) of a heat insulating material containing the entirety of at least said exciting coil and said magnetization sensor, and a cooling system (400, 410) of coolant recirculation type for cooling the superconducting system, said apparatus further comprising means (5, 6, 7) for previously computing the relation between the magnetization characteristic and degradation of said sample and comparing the detected magnetization characteristic of said sample with said relation to decide the degree of degradation of said sample at the time of detection.
Claim 12
Dependent Claim
215 words
A degradation evaluating apparatus comprising means (20, 23) for applying a magnetic field to a sample (11), and a magnetization characteristic measuring device measuring a magnetization characteristic of said sample so as to detect the degree of degradation of said sample on the basis of a change in the magnetization characteristic of said sample due to application of said magnetic field, said magnetization characteristic measuring device including an exciting coil (23) in the form of a superconducting coil, a magnetization sensor (340) in the form of a superconducting quantum interference device having a superconducting pickup coil (330) of differential type disposed at the center of said exciting coil, said superconducting pickup coil of different type defining thereinside a space into which said sample (11) can be inserted from the outside, a fluidtight container (110) of a heat insulating material containing the entirety of at least said exciting coil and said magnetization sensor, and a cooling system (400, 410) of coolant recirculation type for cooling the superconducting system, said apparatus further comprising means (5, 6, 7) for previously computing the relation between the magnetization characteristic and degradation of said sample and comparing the detected magnetization characteristic of said sample with said relation to decide the degree of degradation of said sample at the time of detection.
Claim 13
Independent Claim
152 words
An apparatus for inspecting degradation of a metal material comprising an exciting system and a sensor system including means (20, 23) for applying a magnetic field to a measuring object (1), and a magnetization characteristic measuring device measuring a magnetization characteristic of said measuring object to detect the degree of degradation of said measuring object on the basis of a change in the magnetization characteristic of said measuring object due to application of said magnetic field, said magnetization characteristic measuring device including an exciting coil (23) in the form of a superconducting coil, a magnetization sensor (31) disposed at the center of said exciting coil, said sensor being operable at low temperatures, a fluidtight container (110) of a heat insulating material containing the entirety of at least said exciting coil and said magnetization sensor, and a cooling system (400, 410) of a type recirculating a coolant (130) for cooling the superconducting system.
Claim 14
Independent Claim
152 words
An apparatus for inspecting degradation of a metal material comprising an exciting system and a sensor system including means (20, 23) for applying a magnetic field to a measuring object (1), and a magnetization characteristic measuring device measuring a magnetization characteristic of said measuring object to detect the degree of degradation of said measuring object on the basis of a change in the magnetization characteristic of said measuring object due to application of said magnetic field, said magnetization characteristic measuring device including an exciting coil (23) in the form of a superconducting coil, a magnetization sensor (31) disposed at the center of said exciting coil, said sensor being operable at low temperatures, a fluidtight container (110) of a heat insulating material containing the entirety of at least said exciting coil and said magnetization sensor, and a cooling system (400, 410) of a type recirculating a coolant (130) for cooling the superconducting system.
Claim 15
Independent Claim
153 words
An apparatus for evaluating the degree of degradation of a very small sample (11) taken from a part of a measuring object (1), comprising means (20, 23) for applying a magnetic field to said sample, and a magnetization characteristic measuring device measuring a magnetization characteristic of said sample, said magnetization characteristic measuring device including an exciting coil (23) in the form of a superconducting coil, a magnetization sensor (340) in the form of a superconducting quantum interference device having a superconducting pickup coil (330) of differential type disposed at the center of said exciting coil, said superconducting pickup coil of differential type defining thereinside a space into which said sample can be inserted, a fluidtight container (110) of a heat insulating material containing the entirety of at least said exciting coil and said magnetization sensor, and a cooling system (400, 410) of a type recirculating a coolant (130) for cooling the superconducting system.
Claim 16
Independent Claim
153 words
An apparatus for evaluating the degree of degradation of a very small sample (11) taken from a part of a measuring object (1), comprising means (20, 23) for applying a magnetic field to said sample, and a magnetization characteristic measuring device measuring a magnetization characteristic of said sample, said magnetization characteristic measuring device including an exciting coil (23) in the form of a superconducting coil, a magnetization sensor (340) in the form of a superconducting quantum interference device having a superconducting pickup coil (330) of differential type disposed at the center of said exciting coil, said superconducting pickup coil of differential type defining thereinside a space into which said sample can be inserted, a fluidtight container (110) of a heat insulating material containing the entirety of at least said exciting coil and said magnetization sensor, and a cooling system (400, 410) of a type recirculating a coolant (130) for cooling the superconducting system.
Claim 17
Independent Claim
89 words
An apparatus for inspecting degradation of a metal material used in a nuclear reactor by means of magnetic diagnosis, comprising cable means (900) for suspending said inspecting apparatus from a crane (620) located above a reactor container (600) so that internal equipments of the reactor container can be inspected, and a fluidtight inspection driver (9) including vacuum-actuated attachments (892) for fixing said inspecting apparatus to the inner wall of a pressure vessel (610) of the reactor, and means (894 -898) for actuating three-dimensional scanning movements of said inspecting apparatus.
Claim 18
Independent Claim
89 words
An apparatus for inspecting degradation of a metal material used in a nuclear reactor by means of magnetic diagnosis, comprising cable means (900) for suspending said inspecting apparatus from a crane (620) located above a reactor container (600) so that internal equipments of the reactor container can be inspected, and a fluidtight inspection driver (9) including vacuum-actuated attachments (892) for fixing said inspecting apparatus to the inner wall of a pressure vessel (610) of the reactor, and means (894 -898) for actuating three-dimensional scanning movements of said inspecting apparatus.
Claim 19
Independent Claim
73 words
An apparatus for inspecting degradation of a metal material of pipes of a primary piping system of a nuclear reactor by means of magnetic diagnosis, comprising an inspection driver (9) including means (810, 821, 826, 827) for moving said inspecting apparatus in the axial direction of a pipe (613), means (811, 823, 825) for moving said inspecting apparatus in the circumferential direction of said pipe, and magnetic shielding means for minimizing magnetic noise.
Claim 20
Independent Claim
73 words
An apparatus for inspecting degradation of a metal material of pipes of a primary piping system of a nuclear reactor by means of magnetic diagnosis, comprising an inspection driver (9) including means (810, 821, 826, 827) for moving said inspecting apparatus in the axial direction of a pipe (613), means (811, 823, 825) for moving said inspecting apparatus in the circumferential direction of said pipe, and magnetic shielding means for minimizing magnetic noise.
Claim 21
Independent Claim
115 words
An apparatus for inspecting degradation of a metal material, comprising means (20, 23) for applying a magnetic field to a measuring object (1), and a magnetization characteristic measuring device measuring a magnetization characteristic of said measuring object with high accuracy so as to detect the degree of degradation of said measuring object on the basis of a change in the magnetic characteristic of said measuring object due to application of said magnetic field, said magnetization characteristic measuring device including a superconducting quantum interference device (33) capable of detecting the magnetization characteristic of said measuring object with high accuracy, and a pickup coil (330) of a normal conducting material associated with said superconducting quantum interference device.
Claim 22
Independent Claim
115 words
An apparatus for inspecting degradation of a metal material, comprising means (20, 23) for applying a magnetic field to a measuring object (1), and a magnetization characteristic measuring device measuring a magnetization characteristic of said measuring object with high accuracy so as to detect the degree of degradation of said measuring object on the basis of a change in the magnetic characteristic of said measuring object due to application of said magnetic field, said magnetization characteristic measuring device including a superconducting quantum interference device (33) capable of detecting the magnetization characteristic of said measuring object with high accuracy, and a pickup coil (330) of a normal conducting material associated with said superconducting quantum interference device.
Claim 23
Independent Claim
91 words
An apparatus for detecting degradation of a metal material, comprising means (24, 25) for applying a magnetic field to a measuring object (1) and then demagnetizing to produce a residual magnetism in said measuring object, a high-sensitivity magnetization sensor (36) sensing said residual magnetism, a data base (61) storing previously acquired data of the relation between changes in the residual magnetism and degradation of said measuring object, and a computer (60) deciding the degree of degradation of said measuring object on the basis of the data stored in said data base.
Claim 24
Independent Claim
91 words
An apparatus for detecting degradation of a metal material, comprising means (24, 25) for applying a magnetic field to a measuring object (1) and then demagnetizing to produce a residual magnetism in said measuring object, a high-sensitivity magnetization sensor (36) sensing said residual magnetism, a data base (61) storing previously acquired data of the relation between changes in the residual magnetism and degradation of said measuring object, and a computer (60) deciding the degree of degradation of said measuring object on the basis of the data stored in said data base.
References Cited (Backward Citations)
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