KR101575188B1 - Dual nondestructive defect detecting system combined with a local magnetic signal removal unit - Google Patents

Abstract

The present invention relates to a dual non-destructive defect inspection system incorporating a local magnetic field signal rejection unit, and more particularly, to a dual non-destructive defect inspection system in which a metal roll of a rolling process apparatus is measured by an eddy current defect measurement method, The present invention relates to a dual non-destructive defect inspection system in which a magnetic field signal caused by a change in physical properties of a metal roll is removed by a local magnetic field signal removing unit to improve a defect inspection error of a metal roll.

Description

[0001] The present invention relates to a dual nondestructive defect detecting system combined with a local magnetic field signal removing unit,

The present invention relates to a dual non-destructive defect inspection system incorporating a local magnetic field signal rejection unit, and more particularly, to a dual non-destructive defect inspection system in which a metal roll of a rolling process apparatus is measured by an eddy current defect measurement method, The present invention relates to a dual non-destructive defect inspection system in which a magnetic field signal caused by a change in physical properties of a metal roll is removed by a local magnetic field signal removing unit to improve a defect inspection error of a metal roll.

An eddy current metal defect detection method causes an eddy current to flow in a conductor close to a magnetic field whose direction changes. If there is a physical defect with a space in the conductor, the flow of the eddy current is hunted and the defect in the conductor is inspected by measuring the hunting. Defects include cracks, microholes or corrosion. This method is a non-destructive inspection method which is widely used to inspect the occurrence of defects due to fatigue or corrosion of metals used in power plants, aerospace, aerospace, roads or buildings, It is used to test whether or not a defect has occurred.

The eddy current defect inspection method mainly examines defects on the surface, but the depth of penetration depends on the depth of penetration of the electromagnetic wave into the metal. The depth of penetration leads to the eddy current damping according to the thickness. It is used as the principle of measuring the thickness of metal. It is used to measure the thickness of worn automobile disk by non-destructive method.

Metal roll defect inspection is to inspect the metal roll before the rolling process to process the metal using a plurality of metal rollers made of metal. The metal rolling process is performed at a low temperature or a high temperature, but the low temperature processing method gives more stress to the metal roll during rolling, and the physical properties of the metal roll are changed. The changed physical properties of the metal rolls require inspection errors in defect inspection and techniques for separating signals due to defects and changes in physical properties.

The change in the local physical properties of the metal is caused by the distortion of the atomic arrangement due to stress, vacancy of the atom, etc., and is locally magnetized by the driving coil during the eddy current defect detection, do. This magnetization signal changes the induction magnetic field and is interfered with the original purpose of the metal roll defect inspection apparatus, which is required to detect defects only in conjunction with changes in physical properties and signals generated from defects.

Patent Document 1 provides a technique for a eddy current array sensor that detects defects only by separating signals generated from defects and changes in physical properties due to stress of metal rolls generated during metal roll inspection using an eddy current, but disadvantage .

1. Korean Patent No. 10-1312296 (Feb.

In order to solve the above problems, the present invention provides a method of measuring a magnetic field signal caused by a change in physical properties of a metal roll due to a stress generated in a rolling process of a metal material by measuring a local magnetic field signal To thereby provide a dual non-destructive defect inspection system which improves the defect inspection error of the metal roll.

A dual non-destructive defect inspection system according to the present invention for solving the above-mentioned problem is provided with a composite housing having a plurality of sections, a composite housing provided at a side of the composite housing in a scanning direction, A local magnetic field signal removing unit for generating a magnetic field, an eddy current defect measuring unit located at the center of the composite housing and coupled to the driving coil and the magnetic field signal detecting unit, And an ultrasonic defect measuring unit for measuring an internal defect.

A dual non-destructive defect inspection system includes: a roller-type support that is jointed to both sides of a unit of a nondestructive measurement device so as to be variable in accordance with a radius of curvature of a metal roll; a roller wheel attached to the underside defect measurement device, Further comprising a control unit for controlling the peripheral device and the peripheral device in the upper part of the defect measuring device and driving the peripheral device in the up, down, left, and right directions to warn and display the presence or absence of a defect in the metal roll by simultaneously performing the eddy current defect measurement and the ultrasonic defect measurement .

The local magnetic field signal removing unit is an electric field generator for magnetizing and saturating a metal roll. The magnetic core of the electric field generator is characterized in that a metal wire coated with an insulator is wound around a soft magnetic material.

The local magnetic field signal removing unit is characterized in that N poles and S poles are simultaneously applied on the outer periphery of the metal roll.

The magnetic core is characterized in that a soft magnetic material plate is formed by overlaying a plurality of layers.

The local magnetic field signal removing unit is a permanent magnet having a magnetic field strength for magnetizing and saturating a metal roll.

The composite housing is characterized by being a non-magnetic material.

Wherein the metal housing side surface of the composite housing forms a curved surface in conformity with the radius of curvature of the flat or metal roll.

Wherein the eddy current defect measurement unit and the ultrasonic defect measurement unit simultaneously or selectively operate to simultaneously display defect measurement results in real time.

A method of inspecting a metal roll of a rotating rolling apparatus using a dual non-destructive defect inspection system includes driving and rotating a metal roll, driving an eddy current measurement unit, initializing and measuring a waiting stage, driving an ultrasonic measuring unit, Inducing a saturation magnetic field in the metal roll by the local magnetic field signal removing unit and moving the non-destructive defect measuring apparatus in the magnetization direction in accordance with the determined speed, simultaneously performing the eddy current defect measurement and the ultrasonic defect measurement, And a step of detecting defects.

The present invention has the effect of detecting the defects of the metal roll more accurately and rapidly by removing the local magnetic field signal removing unit from the eddy current defect detection to remove the change of physical properties due to the stress of the metal roll and the generation of the local magnetic field signal .

The present invention is advantageous in that a non-contact eddy current measurement unit and a contact ultrasonic measurement unit, which are non-destructive methods, can be installed to simultaneously measure defects on the surface and inside of a metal roll.

The present invention is capable of performing both eddy-current defect measurement and ultrasonic defect measurement at the same time and quickly comparing and distinguishing defective signals so that it is possible to perform measurement and defect analysis by an existing skilled expert. have.

The present invention is economical because a magnetic field signal measuring device using a conventional stress sensor is unnecessary.

1 is an installation view of a non-destructive defect measuring apparatus according to the present invention;
2 is a front view and a bottom view of the non-destructive defect measuring apparatus of the present invention.
3 is a perspective view and a front view of a magnetic field elimination unit electromagnet.
4 is a perspective view of a curved composite housing;
5 is defect measurement data before and after application of the local magnetic field signal removal unit.
6 is a flow chart for a measurement method of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings illustrate only the essential features of the invention in order to facilitate clarity of the invention, and the accompanying drawings are not intended to be construed in a limiting sense.

In the present invention, the metal roll refers to a metal or alloy roll capable of inducing an external magnetic field to a roll, and a defective object to be inspected refers to a physical defect having a space, but is not limited thereto.

The present invention relates to a dual non-destructive defect inspection system for measuring defects in a metal roll (10) of a rolling process apparatus, comprising a local magnetic field signal removal unit (20), an eddy current defect measurement unit (30), an ultrasonic defect measurement unit A control unit, a roller type wheel 11, a roller type support 12, a peripheral device, an external support frame and a display unit.

FIG. 1 is an installation view showing a non-destructive defect measuring apparatus in contact with a metal roll in a dual non-destructive defect inspection system, and FIG. 2 is a side view and a bottom view showing the non-destructive defect measurement apparatus 50.

The non-destructive defect measuring apparatus 50 is provided with a local magnetic field signal removing unit 20, an eddy current defect measuring unit 30 and an ultrasonic defect measuring unit 40, which are installed in a composite housing 51 having respective sections, A non-destructive defect measurement can be performed. They can also be manufactured independently and used for the measurement of defects in metal plates, metal pipes, etc. other than metal rolls.

3 shows a perspective view and a front view of the local magnetic field signal elimination unit electromagnet, which is composed of a magnetic core 21, a coil 22 wound around the coil, and a DC power supply, and is installed in the composite housing. The magnetic core 21 uses a material having high magnetic permeability that can contain a large amount of magnetic flux, and silicon steel is generally used but is not limited. Silicon steel refers to steel in which about 5% of silicon is fused to iron. In order to generate a strong magnetic field and prevent eddy currents, a thin silicon steel sheet is used in layers. Also, the amount of silicon is adjusted within 5% to meet the purpose. The DC power supply is board-mounted directly to the composite housing, but can be of a separate type.

Enamel wire, Inconel, etc. are used as the insulated wire which is wound around the magnetic core installed in the local magnetic field signal removal unit. However, it is possible to use the insulated wire which is flexible and has good conductivity.

The strength of the magnetic field of the local magnetic field signal removing unit is designed according to the size of the metal roll in consideration of the saturation magnetic field. Usually, a magnetic field of 600 Gauss is designed and used for the size of the metal roll used in the apparatus of the rolling process. The maximum value of the magnetic field strength is designed to be sufficiently large because the saturation magnetic field is applied to the metal roll.

The local magnetic field signal removing unit 20 maintains a constant distance from the outer periphery of the metal roll by the proximity sensor and the vertical holding device as a peripheral device, magnetizes the metal roll by applying the N pole and the S pole at the same time, At the same time, the non-destructive defect measuring apparatus performs the measurement of the eddy current defect and the ultrasonic defect. The direction of the saturation magnetic field of the local magnetic field is parallel to the outer periphery of the metal roll, but may be vertical in the case of a small metal roll.

The local magnetic field signal removing unit 20 removes the local magnetic field signal generated by the stress in the metal roll by the magnetic field saturation method. Therefore, the manpower operating the present invention in the field can more easily interpret eddy current measurement values.

The electric field generator of the local magnetic field elimination unit 20 may be replaced with a permanent magnet having a magnetic field strength capable of saturating a metal roll.

The eddy current defect measurement unit 30 includes a drive coil for driving a eddy current to induce a magnetic field in a metal roll, a recognition coil array for detecting a magnetic field signal changed by a defect in the metal roll, and a signal processor for separating a signal detected in the recognition coil array . The recognition coil array is connected in series with the first recognition coil and the second recognition coil and transmits data in a single channel or multiple channels in the signal processing section.

The eddy-current defect measuring unit 30 maintains a predetermined gap on the outer periphery of the metal roll by a proximity sensor and a vertical holding device as a peripheral device, and is positioned at one side of the local magnetic field signal removing unit, Scans and detects defects in the metal roll.

The eddy current defect measurement unit 30 detects a defect by measuring a change in the magnetic field signal induced in the metal roll in the drive coil so that there is no problem in measuring and detecting a change in the magnetic field signal in the defect in the ideal conductor. However, when the metal is subjected to an external shock or pressure, it is stressed and the local magnetic field is increased. This local magnetic field changes the magnetic field induced by the driving coil to cause a change in the magnetic field signal like a defect . This local magnetic field signal is different from the original purpose of detecting a physical defect, which is a major problem in the measurement of an eddy current defect.

In the prior art, a method of distinguishing a change in a magnetic field signal due to stress from a defect using a stress sensor and a magnetic field detecting device without magnetization of a metal roll was used, but it was difficult to detect the stress sensor. The local magnetic field canceller removes the local magnetic field due to stress by applying a strong magnetic field from the outside to the locally aligned magnetic field and aligning the magnetic field to one side.

4 is a perspective view showing the curved composite housing 52. Fig. The curved composite housing is designed to have a curved shape 52 in conformity with the outer periphery of the metal roll, and the sensor can be installed perpendicular to the outer periphery of the metal roll to increase the sensitivity of the measurement. The flat shape 51 of the composite housing is used when the metal roll is much larger than the width of the composite housing so that the outer periphery of the metal roll is near plane to the sensor and the curved shape 52 is applied to a metal roll of relatively small size.

5 shows the front and rear (101, 202) of the eddy current measurement results measured with the magnetic field applied to the metal roll using the local magnetic field signal remover. It can be seen that the local magnetic field signal due to the stress disappears from the detection of the change in the driving induction field, and the signal due to the defect is easily distinguished.

The ultrasonic defect measurement unit measures surface defects and internal defects by a contact-type nondestructive measurement method. The measured values of surface defects and internal defects are used to complement each other with the measured values obtained from the eddy current defect measurement, thereby improving the reliability of defect detection and analysis.

The non-destructive defect measurement unit is operated independently and can be used for defect measurement by applying ultrasonic defect measurement unit only to a non-metallic material such as concrete.

The control unit controls the non-destructive defect measuring device to move horizontally or vertically with a motor using a guide rail provided with threaded external support frames. In addition, the scan speed is controlled and the display unit is controlled through a separate window.

The roller-type supporter capable of adjusting the angle is installed on both sides of the eddy-current defect measuring apparatus and the ultrasonic defect measuring apparatus and supports the center driving and the sensor unit, and is connected by a joint so as to be variable according to the size of the metal roll to be measured have. The support is formed of a roller type rotating at the end because the metal roll rotates, and the roller can be made of rubber, synthetic resin, or the like.

Roller-type wheels mounted on the sensor portion of the composite housing 51 are used to facilitate the scanning of the sensors and to maintain constant spacing or contact with the metal rolls.

The peripheral device includes upper and lower guide rails attached to the outer support frame to control the non-destructive defect measuring apparatus, a spring rod, a motor, a control unit, a proximity sensor, and a hydraulic device. The upper and lower guide rails serve to move the non-destructive defect measuring device up and down by motor or manually and are controlled by the control unit.

The proximity sensor and the plurality of spring rods individually provided on the non-destructive defect measuring apparatus are arranged so that the local magnetic field signal removing unit and the eddy current defect measuring unit maintain a predetermined interval in the metal roll, and the ultrasonic defect measuring unit Thereby maintaining the contact.

Proximity sensors may be self-proximity sensors, ultrasonic proximity sensors, or optical proximity sensors.

The spring rod is installed on the upper portion of the non-destructive defect measuring apparatus to prevent excessive pressure from being applied to the roller-type wheel and the roller-type support.

The display unit is composed of a control window and a measurement result window. The measurement result window displays the eddy current defect measurement result, ultrasonic measurement result, and correlation data of two results in real time, displays a specific color when a defect is found, and generates a warning sound.

The composite housing is designed to be curved 52 to match the outer periphery of the metal roll, and the sensor can be installed perpendicular to the outer periphery of the metal roll to increase the sensitivity of the measurement. The flat shape 51 of the composite housing is used when the metal roll is larger than the width of the composite housing so that the outer periphery of the metal roll is close to the plane with respect to the sensor and the curved shape 52 is applied to the metal roll of relatively small size.

The dual non-destructive defect inspection system includes a rotating device of a rolling device metal roll, which rotates the metal roll at a constant speed when measuring defects of the metal roll.

FIG. 6 is a flow chart of a method of inspecting a dual non-destructive defect inspection system. The method includes supplying power to the dual non-destructive defect inspection system and activating the system, driving the metal roll to rotate at a constant speed, Driving an eddy current measurement unit, driving an initialization and measurement waiting unit, an ultrasonic measurement unit, moving the initialization and measurement standby unit and the non-destructive defect measurement unit in the magnetization direction at a predetermined speed, And simultaneously performing the eddy current defect measurement and the ultrasonic defect measurement, thereby detecting the surface and internal defects of the metal roll.

The measurement of the flat metal defects of the non-destructive defect measuring apparatus further includes a device in which the angles of the joints jointed on both sides are 180 ° and the metal plate to be measured is moved perpendicular to the scanning direction.

10: metal roll 11: roller type wheel
12: roller type support 13: joint
14: spring load 20: local magnetic field signal cancellation unit
21: core 22: coil
23: Stimulus 30: Eddy current defect measurement unit
31: Eddy current sensor 40: Ultrasonic defect measurement unit
41: ultrasonic sensor 50: non-destructive defect measuring device
51: Composite housing (flat type) 52: Composite housing (curved type)
101: local magnetic field signal due to stress 201: local magnetic field signal removed

Claims (9)

A dual non-destructive defect inspection system for detecting defects in a rotating rolling device metal roll,
A composite housing having a plurality of sections;
A local magnetic field signal removing unit which is provided on the side of the composite housing in the scanning direction and which is located at a predetermined interval on the outer periphery of the metal roll to generate a saturation magnetic field;
An eddy current defect measurement unit located at the center of the composite housing and coupled to the drive coil and the magnetic field signal detection unit; And
And an ultrasonic defect measurement unit installed at one side of the eddy current defect measurement unit in the composite housing to measure defects on the surface and inside of the metal roll. The method according to claim 1,
The local magnetic field signal removing unit is an electric field generator for magnetizing and saturating a metal roll,
The magnetic core of the electric field generator is of a horseshoe shape, which is made by stacking a soft magnetic material plate with a plurality of layers,
Wherein a metal wire coated with an insulator is wound around the center of the magnetic core. The method according to claim 1,
Wherein the local magnetic field signal removing unit is configured such that N poles and S poles are simultaneously applied to the outer periphery of the metal roll. The method according to claim 1,
Wherein the local magnetic field elimination unit is a permanent magnet having a saturation magnetic field intensity with respect to the metal roll. The method according to claim 1,
A non-destructive measuring device so as to be variable in accordance with the radius of curvature of the metal roll;
A roller type wheel attached to a lower portion of each unit of the non-destructive defect measurement device;
A peripheral device installed on top of the non-destructive defect measuring device; And
The dual non-destructive defect inspection system according to claim 1, wherein the display unit includes a control unit for controlling the peripheral device to drive up and down and left and right to simultaneously perform eddy current defect measurement and ultrasonic defect measurement to warn and display the presence or absence of a defect in the metal roll. The method according to claim 1,
Wherein the composite housing is a non-magnetic material. The method according to claim 1,
Wherein a cross section of the metal housing of the composite housing is curved to conform to a radius of curvature of the flat or metal roll. The method according to claim 1,
Wherein the eddy current defect measurement unit and the ultrasonic defect measurement unit are operated simultaneously or selectively, and the defect measurement result is simultaneously displayed in real time. A method of inspecting a metal roll of a rotating rolling apparatus using a dual non-destructive defect inspection system,
Driving the metal roll to rotate;
Driving an eddy current measurement unit and waiting for initialization and measurement;
Driving an ultrasonic measuring unit and waiting for initialization and measurement;
Inducing a saturation magnetic field on the metal roll by the local magnetic field signal removal unit; And
Moving the non-destructive defect measuring apparatus in the magnetization direction at a predetermined speed and simultaneously performing eddy current defect measurement and ultrasonic defect measurement to detect the surface and internal defects of the metal roll. Way.

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