CN1741866A - Method of manufacturing steel strip or surface-treated steel strip - Google Patents

Abstract

A method of manufacturing a surface treated steel strip, comprising a hot rolling step for manufacturing a hot rolled steel strip by hot rolling a steel piece, a property measurement step for measuring the properties of the surface layer part of the steel strip to provide measurement results, a predicting step for predicting whether measured portions become apparent or not as surface defects in the steps ranging from the property measurement step to a final consumption by using the results of the measurement of the surface layer part to provide predicted results, a determination step for determining, according to the predicted results, a subsequent manufacturing step and manufacturing conditions, and the manufacturing step for manufacturing the steel strips or surface-treated steel strips based on the determined manufacturing step and manufacturing conditions.

Description

The manufacture method of steel band or surface-treated steel strips

Technical field

The present invention relates to the manufacture method of cold-rolled strip or surface-treated steel strips.Relate in particular in the cold-rolled strip of the less skin section excellent of the defective of manifesting in the manufacturing process of final finished or the manufacture method of surface-treated steel strips.

Background technology

Because the High Level of the credit rating of pursuing in sheet products in recent years is stronger for the expectation of the less steel band of injurous defects such as blemish.For example, jar cold-rolled steel sheet, steel plating plate etc. are used, made to automobile.Object lesson has, and in automobile cold-rolled steel plate, produces blemish owing to sneak into non-metallic inclusion etc. in the stage at system steel etc. in steel.Even wherein some carries out application and with the naked eye also can confirm, become big problem in appearance.

Other example has the automobile clad steel sheet.Automobile with clad steel sheet via system steel operation, manufacturings such as hot-rolled process, pickling process, cold rolling process, plating process, and become the automobile parts through further stamping procedure, coating process.Automobile with one of major defect in the clad steel sheet be called generally that squamous is folding, crack, abrasive blemish, in automobile as final finished, owing to can see that defect part is obviously different with other intact part, generation diminishes the problem of outward appearance, perhaps, when defective reaches very serious degree, when drawing, produce harms such as damaging forcing press.

When the folding occurrence cause of squamous is to make the nonmagnetic metal field trash that produces in the steel operation, perhaps be to sneak into steel when inner etc. when occurrence cause at system steel operation and hot-rolled process entrance side (before the hot rolling) oxide, in whole manufacturing process, it is generally acknowledged that origin is the upstream process side.And, because through hot rolling, cold rolling, plating processing, above-mentioned manifesting of blemish.

In order to reduce the defective that has in the above-mentioned example, to make high-quality finished product, need a kind of like this manufacture method, that is, in whole operation, detect the part that will become defective, and formulate suitable countermeasure according to this result in the stage as far as possible early.

Therefore, as with above-mentioned the former technology of automobile cold-rolled steel plate correspondence, as checking out the example of the blemish of manifesting, for example patent documentation 1: it is disclosed like that the spy opens clear 61-219403 communique.The position and the size of steel strip surface damage in the continuous cold rolling production line, are removed the damage of steel band at the roller mill entrance side after hot rolled strip continuous acid-washing production line outlet side detects pickling processes.Illustrate at embodiment, be provided as the surface defect detection apparatus of test section, and add brush roll etc. at the abrasive particle that continuous cold rolling production line entrance side is provided as defective removal portion at the pickling lines outlet side.

And, same conduct is applicable to the technology of the former cold-rolled steel sheet, at patent documentation 2: the spy opens and has proposed a kind of method in the 2001-191206 communique, promptly by machining remove the folding damage grade of the squamous that on steel plate, produces surface damage, by rolling elimination cutter trade.

In the prior art of above-mentioned patent documentation 1,2 record, only so that manifesting, the tangible blemish of quality problems (injurous defect) are object at examination phase.

On the other hand, for example, according to our probe to blemish such as the squamous in the above-mentioned latter's the automobile usefulness clad steel sheet fold, in blemish such as squamous folds, the not defective of manifesting is arranged in hot rolled plate or acid-cleaning plate stage unusual part, promptly exist owing to do not display, or an only considerably less part exposes, therefore not have the defective damaged in this stage on the surface.These defectives are being removed top layer oxide skin through overpickling, cold rolling after, manifesting behind the plating or after the punch process.

The blemish of manifesting after can detecting plating by surface defect inspection apparatus behind the plating.But, even distinguish that in this stage zero defect is arranged since on steel band is made near final operation, therefore be difficult to resemble and remove defect part the prior art and innoxious.And according to its check result, other means that can take also are restricted.And the processing from the upstream process such as system steel operation that produce blemish reasons such as squamous is folding will be through certain hour just to checking operation, thereby upstream the operation feedback of creating conditions is also restricted.

For the above reasons, before the manifesting of blemish such as squamous is folding after plating is handled, blemish whether can occur after must judging plating, but this is impossible in the prior art.

In view of above problem, task of the present invention is to provide a kind of manufacture method of steel band or surface-treated steel strips of skin section excellent, after hot rolling in each operation of final consumption (surface treatment, drawing, applications etc. such as pickling, cold rolling, heat treatment, plating, plating porcelain), even for the unusual part of manifesting not, also can take the countermeasure in the suitable manufacturing, in each operation of final consumption, reducing defective, even perhaps there is defective, also be difficult to produce the obstacle in the manufacturing.

Summary of the invention

The invention provides have hot-rolled process, characteristic measurement operation, prediction operation, decision operation and the steel band of manufacturing process or the manufacture method of surface-treated steel strips.

Hot-rolled process comprises steel disc is carried out hot rolling to make hot rolled strip.The characteristic measurement operation comprises that the skin section characteristic of measuring above-mentioned steel band is to obtain measurement result.The prediction operation is included in after the above-mentioned characteristic measurement operation in each operation of final consumption, the result who uses above-mentioned skin section to measure, and whether the position that prediction is measured is predicted the outcome as manifesting of blemish.Determining operation to comprise according to above-mentioned predicting the outcome determines later manufacturing process and creates conditions.Manufacturing process comprises according to the manufacturing process of decision and creates conditions and make steel band or surface-treated steel strips.

The manufacture method of above-mentioned steel band or surface-treated steel strips preferably also has according to above-mentioned manufacturing process before above-mentioned hot-rolled process and the operation of creating conditions and feeding back of predicting the outcome.

Above-mentioned prediction operation is at least a from following selection preferably.

(a) the prediction operation comprises: use above-mentioned skin section measurement result, and use the target of creating conditions until the steel band of predicting, actual value, in predetermined the creating conditions, purposes, comprise the information that the information conduct more than at least a in the specification of the finished product of checking specification is used to predict of operation after this, the position that prediction is measured is predicted the outcome as blemish manifesting whether.

(b) the prediction operation comprises: utilize the distributed intelligence have with the depth direction of the skin section of other parts different qualities to predict, predicted the outcome.

(c) prediction operation comprise: after above-mentioned characteristic measurement operation in each manufacturing process that obtains final finished, whether the position that the result who uses above-mentioned skin section to measure predicts mensuration from be predicted as defective will the part of manifest determine remove object portion as manifesting of blemish.At this moment, above-mentioned manufacturing process comprises: utilize part to remove device and remove and comprise above-mentioned zone of removing object portion, then, cold-rolled strip.

Above-mentioned decision operation preferably includes: according to the above-mentioned later manufacturing process of decision that predicts the outcome, create conditions and trimmed size.

Above-mentioned characteristic measurement operation preferably includes: make steel band measure face skin section ac magnetization, by measuring the variation that is caused the exchange flux that produces by the skin section characteristic, measure the skin section characteristic of steel band.Specifically, be more preferably by selecting one of following carrying out.

(A) be used in plural at least Magnetic Sensor that the general width direction of steel band is set up in parallel and detect the variation that causes the exchange flux that produces by the skin section characteristic,, measure the skin section characteristic of steel band based on the differential signal of the width of detection signal.

At this moment, what wish is, relative with steel strip surface respectively and approximate vertical and and width of steel band direction almost parallel be set up in parallel 3 foot section of E type kicker magnet, apply alternating current to the primary winding that is wound on the central foot section, make the steel band excitation, secondary coil is wound on respectively on 2 foot section in the outside, based on the difference of the voltage of responding on secondary coil, measures the skin section characteristic of steel band.

(B) make the steel band ac magnetization, make the width scanning of Magnetic Sensor,, measure the skin section characteristic of steel band based on the variation of the magnetic sensor signal of following scanning to produce at steel band.

At this moment, Magnetic Sensor is mechanically moved in the width of steel band direction,,, measure the skin section characteristic of steel band based on the variation of the magnetic sensor signal of following scanning to produce with at the width of steel band scanning direction.And, also can dispose a plurality of Magnetic Sensors in the width of steel band direction, switch by electronics and select Magnetic Sensor, carry out the width of steel band scanning direction, based on the variation of the magnetic sensor signal of following scanning to produce, measure the skin section characteristic of steel band.

(C) and approximate vertical relative with steel strip surface and and the width almost parallel ground of steel band dispose the foot section more than 4 of comb shape kicker magnet side by side, wherein coil is wound on the foot section of comb shape kicker magnet, the selection that timeliness ground switches the group of 3 adjacent foot section, and in 3 foot section selecting, apply alternating current to the primary winding that is wound on the central foot section, carry out excitation, secondary coil is wound on respectively on 2 foot section in the outside, based on the differential signal of the voltage of on secondary coil, responding to, measure the skin section characteristic of steel band.

(D) under the dc magnetization grade of steel band excitation comes down near zero state, the frequency that makes ac magnetization is in the scope of 100kHz to 10MHz and make steel band measure face skin section ac magnetization, by measuring the variation that causes the exchange flux that produces by the skin section characteristic, measure the skin section characteristic of steel band.

The manufacture method of above-mentioned steel band or surface-treated steel strips also had in the final outbound of the steel band stage:

Measure the skin section characteristic measurement operation of steel band skin section characteristic;

Only measure the surface characteristic of steel strip surface characteristic and measure operation;

After this in each operation of final consumption, use above-mentioned skin section measurement result and surface characteristic measurement result predict this determination part as the blemish of quality problems manifesting of the defective prediction operation of manifesting whether;

According to the above-mentioned manufacturing process's conditional decision operation that predicts the outcome decision manufacturing process and create conditions.

And, the invention provides the manufacture method that has hot-rolled process, detects operation, determines operation and remove the steel band or the surface-treated steel strips of operation.

Hot-rolled process comprises steel disc is carried out hot rolling to make hot rolled strip.Detect operation and be included in when carrying out the steel band AC excitation,, detect the defective candidate that is included in the steel band by detecting the variation that causes the exchange flux that produces by defective.The decision operation is included in by in the detected defective candidate of above-mentioned detection operation, will serve as that the top layer or the blemish candidate of the elongated shape on long limit determines to removing object with the rolling direction of above-mentioned steel band.Remove operation and comprise and selecting, and carry out grinding or cutting comprising by the zone of removing object of above-mentioned decision operation decision.

Above-mentioned detection operation is preferably by selecting one of following carrying out.

(a) make the steel band ac magnetization, utilize the Magnetic Sensor more than 2 that is set up in parallel in steel band general width direction to detect magnetic flux, the differential signal based on the width of detection signal detects defective.

(b) relative with steel strip surface respectively and approximate vertical and and width of steel band direction almost parallel be set up in parallel 3 foot section of E type kicker magnet, apply alternating current to the primary winding that is wound on the central foot section, make the steel band excitation, secondary coil is wound on respectively on 2 foot section in the outside, the difference of the voltage that will respond on secondary coil is as above-mentioned differential signal, based on this differential signal, detect defective.

(c) make the steel band ac magnetization, make the width scanning of Magnetic Sensor at steel band, the variation based on the magnetic sensor signal of following scanning to produce detects defective.

By Magnetic Sensor is mechanically moved in the width of steel band direction, make Magnetic Sensor at the width of steel band scanning direction, the variation based on the magnetic sensor signal of following scanning to produce detects defective.Perhaps, dispose a plurality of Magnetic Sensors in the width of steel band direction, switch by electronics and select Magnetic Sensor, make Magnetic Sensor at the width of steel band scanning direction, the variation based on the magnetic sensor signal of following scanning to produce detects defective.

(d) and approximate vertical relative with steel strip surface and and the width almost parallel ground of steel band dispose the foot section more than 4 of comb shape kicker magnet side by side, wherein coil is wound on the foot section of comb shape kicker magnet, the selection that timeliness ground switches the group of 3 adjacent foot section, and in 3 foot section selecting, apply alternating current to the primary winding that is wound on the central foot section, carry out excitation, secondary coil is wound on respectively on 2 foot section in the outside, differential signal based on the voltage of responding on secondary coil detects defective.

And, in above-mentioned detection operation, the dc magnetization grade that is preferably in the steel band excitation comes down near under zero the state, the frequency that makes ac magnetization is in the scope of 100kHz to 10MHz and carry out the AC excitation of steel band, simultaneously, by detecting the variation that causes the exchange flux that produces by defective, detect the defective candidate that is included in the steel band.After evener, on the position of the opposite face of face of removing with roller supporting and check surface or defective of steel band, implement above-mentioned defects detection operation, defective is removed at least one side in the operation.The unit tension that above-mentioned defects detection operation preferably includes at steel band is 0.3kgf/mm ²Detect defective when above.

Description of drawings

Fig. 1 is the sketch of formation of the skin section characteristic detecting apparatus of expression width differential mode of the present invention.

Fig. 2 is the sketch of formation of the skin section characteristic detecting apparatus of expression E type approach sensor of the present invention.

Fig. 3 is the sketch of formation of the skin section characteristic detecting apparatus of expression width scan mode of the present invention.

Fig. 4 is the sketch of formation of the skin section characteristic detecting apparatus of expression electron scanning mode of the present invention.

Fig. 5 (a), Fig. 5 (b), Fig. 5 (c) are the sketches of formation of the skin section characteristic detecting apparatus of expression comb shape approach sensor of the present invention; Fig. 5 (a) is to use foot section 10a, 10b, 10c to produce the example of exchange flux, Fig. 5 (b) is to use foot section 10b, 10c, 10d to produce the example of exchange flux, and Fig. 5 (c) is to use foot section 10c, 10d, 10e to produce the example of exchange flux.

Fig. 6 (a) is the figure of configuration of expression skin section characteristic detecting apparatus of the present invention, the figure of the signal waveform of the Magnetic Sensor of Fig. 6 (b) when to be expression by the skin section characteristic detecting apparatus of Fig. 6 (a) obtain the small top layer characteristic abnormal portion of standard.

Fig. 7 (a) is the figure of configuration of expression skin section characteristic detecting apparatus of the present invention, and Fig. 7 (b) is expression by the signal waveforms of the skin section characteristic detecting apparatus of Fig. 7 (a) Magnetic Sensor when the elongated top layer characteristic abnormal portion of rolling direction scanning rolling direction.

Fig. 8 is the key diagram of an example of embodiment of the present invention.

Fig. 9 is the structure chart of expression defective generation prediction unit of the present invention.

Figure 10 is the figure of expression basic comprising example of the present invention (master operation).

Figure 11 is the figure that expression the present invention uses the prediction flow process of exchange flux.

Figure 12 is illustrated in the blemish of manifesting and the figure of the relation of the skin section characteristic abnormal portion of mensuration in advance in certain operation of the present invention.

Figure 13 is the figure of the expression basis of the present invention program example (decision finished product kind, the example of creating conditions) that predicts the outcome decision manufacturing process, create conditions.

Figure 14 is that expression basis of the present invention predicts the outcome decision manufacturing process, the figure of the program example example of operation (decision) of creating conditions.

Figure 15 is the figure of the example predicted according to depth location in of the present invention the predicting the outcome of expression.

Figure 16 is the figure of an example of the handling process of expression manifesting of defective prediction unit of the present invention.

Preferred implementation

The present invention is the manufacture method of the steel band or the surface-treated steel strips of skin section excellent, by steel being carried out it is characterized in that after hot rolling, having following operation in the manufacture method of hot rolling with the steel band of making steel band and surface-treated steel strips and surface-treated steel strips at least:

(1) the skin section characteristic measurement operation of mensuration steel band skin section characteristic;

(2) utilize this skin section measurement result,, predict that its determination part is whether as manifesting of the defective prediction operation of manifesting of blemish after this in each operation of final consumption;

(3) according to the manufacturing process's conditional decision operation that predicts the outcome decision manufacturing process and create conditions that obtains.

The present invention not only measures the blemish of this moment in skin section characteristic measurement operation, and measures as the blemish skin section characteristic of manifesting not also.That is, not only with steel strip surface and also with the abnormal portion of the inside (skin section) on surface as determination object.Afterwards, will as blemish also not the skin section characteristic records of manifesting be potential defective part.

Then, in manifesting of defective prediction operation, according to skin section characteristic measurement result, prediction is as the possibility of manifesting of blemish in operation after this.Here, as potential defective part, except foreseeable will the skin section characteristic of manifesting in the manufacturing process of outbound, also can be in the treatment process of final consumption with foreseeable, skin section characteristic that will manifesting when promptly the user after outbound carries out punch process etc. is as object.

In manufacturing process's conditional decision operation, when blemish has manifesting possible, decision be used to prevent the change of creating conditions or the operation change of blemish and be used to repair may manifesting part as blemish operation change.Owing to will carry out suitable operation change at the skin section characteristic, therefore wish combinational logic in advance, perhaps actual value or the experimental result according to the past provides correspondence with table.Can not rely on artificial judgment to implement the operation change.

And the present invention is the manufacture method of the steel band or the surface-treated steel strips of skin section excellent, it is characterized in that, also has following operation before cold rolling after hot rolling, carries out cold rolling after these operations.

(4) from manifesting of the defective part of prediction, determine to determine operation as the object of removing of the skin section of removing object;

(5) utilizing part to remove device removes and comprises above-mentioned part of removing the zone of object portion and remove operation.

When the present invention predicts manifesting of defective by manifesting of defective prediction operation,, remove this latent defect portion as manufacturing process and creating conditions.That is, utilize and to remove object decision operation, decision is as skin section position (scope) and the amount of removing (removing the degree of depth) of removing object, and utilizes and partly remove operation and remove this and remove object portion.Then, carry out cold rollingly, make cold-rolled steel sheet, perhaps further implement surface treatment, make surface treated steel plate.

In these inventions, the manufacture method as the steel band or the surface-treated steel strips of skin section excellent is characterized in that before steel band outbound operation, also having following operation.

(6) surface characteristic that is exclusively used in the surface characteristic of measuring steel band is measured operation;

(7) decision is removed indicated object decision operation as the part of removing object or indicated object from the part of manifesting of defective of prediction.

The present invention also measures surface characteristic before the outbound operation outside the top layer characteristic measurement operation after the hot rolling, detect the defective of manifesting at this moment.In manifesting of defective prediction operation, the manifesting of ground the same caluclate table planar defect with foregoing invention.In removing indicated object decision operation, decision is measured part that the blemish of detected abnormal portion and prediction will manifesting as the object part of removing, representing to utilize surface characteristic.

Like this, excision comprises the length direction scope of the part that becomes defective in the steel band in a large number, perhaps is implemented in feedforward such as make marks on the part that forms defective.And, according to predicting the outcome, can be used for guiding, the data of store feedback, perhaps feedback itself to the feedback of creating conditions of the coiled material of making thus.,, in system steel operation, for example change casting rate, cast temperature or continuous casting kind here, perhaps change the heating-up temperature in the hot-rolled process or the setting of coiling temperature with powder as the example of feedback.For this reason, need be stored in the information of creating conditions of inspection object steel band in system steel operation or hot-rolled process in the skin section characteristic detecting apparatus,, make correspondence by comparing with the check result of utilizing the skin section characteristic detecting apparatus.Like this, check, can shorten making the condition that reduces in final activity list planar defect be reflected in the time of system steel operation or hot-rolled process, can improve later fabrication yield by the operation before final operation.

In these inventions, manufacture method as the steel band or the surface-treated steel strips of skin section excellent, it is characterized in that, manifesting of defective prediction operation use until the steel band of predicting create conditions and the difference of target, actual value, predeterminedly in operation after this create conditions, trimmed size, purposes and the information of checking in the specification more than one is as the information that is used to predict.

This invention is not only according to the possibility of skin section characteristic measurement prediction of result as manifesting of blemish, and utilize process up to the upstream process of measuring, lower procedure create conditions and the specification of final finished is predicted.For example, for upstream process, use the chemical composition, upstream process thermal process, rolling condition etc. of steel band to create conditions and difference, the actual value in past and other key element of target.

Here, target is meant that the target in manufacturing planning stage is created conditions or the target trimmed size.For example, the coiling temperature before manufacturing during with hot rolling is a target temperature, is set at 500 ℃, when actual value is 480 ℃, can use target and actual value both sides as the information that is used to predict.Like this, also can use by contrast desired value and actual value.

For lower procedure and final finished, utilize specification, purposes, check criteria and other key element of finished product to predict.Thereby even come to the same thing with the skin section characteristic measurement, according to the various key elements of these upstream process, lower procedure and final finished, it is different that manifesting of defective predicts the outcome, and can use suitable the creating conditions or operation with the purpose correspondence.

And in these inventions, the manufacture method as the steel band or the surface-treated steel strips of skin section excellent is characterized in that, according to predicting the outcome of manifesting of defective prediction operation, changes in trimmed size, purposes and the object-oriented more than one.

And, the manufacture method of the steel band or the surface-treated steel strips of skin section excellent can also be provided, it is characterized in that, before manufacturing, not special provision trimmed size, purposes and object-oriented in advance, as the manufacturing process in trimmed size, purposes and the OO scope of pressing the joint project classification, carry out manifesting of defective of the present invention prediction, according to its result, determine in above-mentioned trimmed size, purposes and the object-oriented etc. more than one, and determine manufacturing process, condition after the next operation to make steel band.Therefore, not restrained by the flow direction of existing logistics, can form logistics flexibly.

The present invention predicts the outcome according to manifesting of defective, not only manufacturing process, the condition of change or decision lower procedure, and change or decision final finished itself, the i.e. specification of finished product, purposes and object-oriented etc.Thus,, migrate, can effectively utilize steel plate by the change (grade reduction) of specification or to purposes that does not constitute defective or object-oriented even when predicting manifesting of defective.

The steel band of skin section excellent or the manufacture method of surface-treated steel strips is characterized in that, in manifesting of defective prediction operation, utilize the thickness internal direction of steel band, i.e. the information of the distribution of the abnormal portion on the depth direction.

In manifesting of the defective prediction operation of this invention, utilize of the distributed intelligence of latent defects such as field trash at the depth direction of skin section, carry out the prediction of manifesting of defective.Thereby, even at this moment as the blemish latent defect of manifesting not, can in operation after this, predict the possibility of its manifesting.At this moment, by the accumulation past data, can improve accuracy of predicting.

In these inventions, also can be as the manufacture method of the steel band or the surface-treated steel strips of skin section excellent, it is characterized in that, in skin section characteristic measurement operation, when making steel band measure face skin section ac magnetization, by measuring the variation of the exchange flux that produces because of the skin section characteristic, measure the skin section characteristic of steel band.

In foregoing invention, in order also to measure skin section inside, as producing the principle of measuring the skin section characteristic on the production line, it is suitable using magnetism method.Wherein, more wish to use the method for exchange flux.Compare with the situation of using dc magnetization, because the influence of skin effect, the penetration depth of magnetic flux is restricted, because flux concentrating near the skin section of steel band, therefore can detect the skin section characteristic expeditiously.

Because same reason, in order to detect the skin section bulk properties, the optical profile type surface examining device that only can detect the surface is inapplicable.And, even when only limiting to estimate surface characteristic,,, therefore, restricted the mensuration precision greatly though the harmless apperance that is present in the surface often becomes noise steel being carried out hot rolled plate stage or pickling stage when being suitable for optical means.And, for utilizing supersonic reflection method,,, generally also be unaccommodated therefore because there is the dead band in the influence of surface echo in skin section though can obtain the information of steel band inside.

In these inventions, also can be as the manufacture method of the steel band or the surface-treated steel strips of skin section excellent, it is characterized in that, skin section characteristic measurement operation makes the steel band ac magnetization, the Magnetic Sensor more than 2 that utilization is set up in parallel in the general width direction of steel band detects magnetic flux, according to the differential signal of the width of detection signal, measure the skin section characteristic of steel band.

In this invention, utilize 2 Magnetic Sensor being set up in parallel at the width of steel band to detect magnetic flux, according to the differential signal of the output of two Magnetic Sensors, measure the skin section characteristic of steel band.Abnormal portion as the skin section of object of the present invention is very small in the C cross section of above-mentioned steel band, and extends into elongated shape in rolling direction.In the characteristic abnormal portion of this top layer, the magnetic flux size that detects according to width position is very different.Therefore, by obtaining the differential signal of 2 the Magnetic Sensor that is set up in parallel at width, can measure the characteristic of this abnormal portion accurately.In addition, in this manual, the width of steel band then is meant and the rectangular direction of the rolling direction of steel band unless otherwise noted.

After obtaining differential signal, for example,, can estimate the unusual degree of characteristic (in the possibility of manifesting whether in each operation of final consumption) according to the size of DC component after the rectification with its rectification.Method, utilization and the ac magnetization electric current that the method for rectification is suitable uses only rectification synchronously and the signal with certain phase difference carry out the existing methods that are used for eddy current testing method such as method of synchronous detection.

In these inventions, also can be as the manufacture method of the steel band or the surface-treated steel strips of skin section excellent, it is characterized in that, in skin section characteristic measurement operation, relative with steel strip surface respectively and be set up in parallel 3 foot section of E type kicker magnet at width of steel band, apply alternating current to the primary winding that is wound on the central foot section, make the steel band excitation, secondary coil is wound on respectively on 2 foot section in the outside, and the difference of the voltage that will respond on secondary coil is as above-mentioned differential signal.

In this invention, use the Magnetic Sensor (E type sensor) of holding concurrently of the magnetizing assembly with E type yoke.Promptly, relative with steel strip surface respectively and approximate vertical and and width of steel band direction almost parallel be set up in parallel 3 foot section of E type kicker magnet, when the primary winding on being wound on central foot section applies alternating current, concentrate the foot section that flows to both sides at the exchange flux that the foot section of central authorities takes place by steel strip surface, and return central foot section by the foot section of both sides.That is, point to the flux concentrating generation of width of steel band direction.Therefore, when the elongated skin section characteristic abnormal portion of the length direction that exists in steel band (rolling direction), magnetic circuit is blocked, and the magnetic flux of detection becomes and changes easily.

Thereby, can precision detect very small and have a skin section abnormal portion of elongated shape in rolling direction in the C cross section of steel band as object of the present invention well.In addition, about the magnetizing assembly arrangement angles of Magnetic Sensor of holding concurrently, even, still can measure in theory with respect to steel strip surface or some skew of width.During enforcement,, then on measuring, there is not obstacle if be configured by the degree of position that can specific latent defect.

In these inventions, also can be as the manufacture method of the steel band or the surface-treated steel strips of skin section excellent, it is characterized in that, in skin section characteristic measurement operation, make the steel band ac magnetization, make the width scanning of Magnetic Sensor,, measure top layer characteristic abnormal portion based on the variation of the magnetic sensor signal of following scanning to produce at steel band.

In this invention, owing to make Magnetic Sensor,, measure the skin section characteristic based on the variation of the magnetic sensor signal of following scanning to produce in the scanning of the width of steel band, can detect the variation of magnetic flux of the width of steel band, and detect top layer characteristic abnormal portion in view of the above.Consequently, can precision detect the skin section characteristic abnormal portion that has elongated shape in the rolling direction of steel plate well.As the direction of magnetization, it is effective especially carrying out force-magnetized at the width of steel band.In addition, when checking in the advancing of steel band, though be called width scanning, in fact also be equal to respect to steel band in oblique scanning, also can obtain action effect of the present invention in this case, the present invention also comprises this situation.

In this invention, the steel band of skin section excellent or the manufacture method of surface-treated steel strips also are provided, it is characterized in that skin section characteristic measurement operation mechanically moves in the width of steel band direction by making Magnetic Sensor, scans in the width of steel band direction.

In this invention, scan as mentioned above by making Magnetic Sensor itself, measure the top layer characteristic of width of steel band direction.As the scanning means, according to the whole bag of tricks such as the known track mode of suitable uses such as position, ball-screw type of drive are set.

And, as invention according to other scan mode, the steel band of skin section excellent or the manufacture method of surface-treated steel strips also are provided, it is characterized in that, in skin section characteristic measurement operation, dispose a plurality of Magnetic Sensors in the width of steel band direction, switch by electronics and select Magnetic Sensor, carry out the width of steel band scanning direction.

In this invention, use the Magnetic Sensor that disposes side by side at width to carry out electron scanning.With foregoing invention together, in these inventions, carry out the scanning of mechanical type, electronic type respectively, use arbitrary method can obtain same effect.Particularly, in the invention of back, owing to carry out electron scanning, compare with mechanical scanning, can carry out high-velocity scanning, even when the determination object high-speed mobile, that can reduce the rolling direction that produced by sweep spacing does not measure the zone.And, owing to there is not movable part, can improve reliability, durability.

And, as invention according to other scan mode, also can be used as the manufacture method of the steel band or the surface-treated steel strips of skin section excellent, it is characterized in that, skin section characteristic measurement operation, relative with steel strip surface and dispose the foot section more than 4 of comb shape kicker magnet side by side at the width of steel band, wherein coil is wound on the foot section of comb shape kicker magnet, the selection that timeliness ground switches the group of 3 adjacent foot section, and in 3 foot section selecting, apply alternating current to the primary winding that is wound on the central foot section, carry out excitation, secondary coil is wound on respectively on 2 foot section in the outside, based on the differential signal of the voltage of responding on secondary coil, measures the skin section characteristic.

In this invention, use comb shape yoke with a plurality of foot section, in these foot section, select adjacent 3 to use in turn as E molded lines circle.Therefore, can realize and use the same action effect of invention of above-mentioned E type sensor, and and foregoing invention same owing to scan at width, do not have moving part by the electronics switching coil, can form structure simple in structure and that fault is few.And, as required, can improve the integrated level and the densification of sensor, simultaneously, because the integrally formed multichannel sensor of energy can improve dimensional accuracy.

And, in these inventions, also can be used as the manufacture method of the steel band or the surface-treated steel strips of skin section excellent, it is characterized in that, in skin section characteristic measurement operation, the dc magnetization grade of steel band excitation comes down to the state near zero during the skin section characteristic measurement, and the frequency of ac magnetization is in the scope of 100kHz to 10MHz.

In each operation of final consumption, because in order to judge that the scope whether this prediction section be measured as manifesting of defective only limits to skin section, thereby preferably make magnetic flux concentrate on skin section as far as possible.For this reason, the penetration depth of magnetic flux (magnetic flux density for the surface 1/e the time the degree of depth) below about 50um, be suitable.

When measuring steel, preferably dc magnetization is near zero state, and frequency is more than 100kHz.And from the stability of relative noise, and in order to make penetration depth within reason shallow, the frequency of ac magnetization is made as below the 10MHz.Therefore, in the present invention, the frequency of ac magnetization is the scope of 100kHz to 10MHz.The frequency of ac magnetization is preferably in below the 1MHz.

In addition, by applying dc magnetization to exchange flux, differential permeability reduces, even use identical excitation frequency, compares with the situation that does not apply dc magnetization, and penetration depth can deepen.Therefore, for realizing the condition determination of a plurality of penetration depths, also can control the dc magnetization grade.

As mentioned above, according to the present invention, in steel band manufacturing process, by after hot rolling, measuring the characteristic of skin section, prediction is in this mensuration stage manifesting not also, the suitable countermeasures such as zone that comprise this part are removed by taking part in the position of manifesting in the arbitrary operation in each operation of final sale after this, expeditiously the few high steel band of quality of manufacturing defect.As steel band, be not limited to pickling steel band, cold-rolled strip especially, especially for handle by it defective easily the surface-treated steel strips such as coated steel strip of manifesting good effect is also arranged.

With Fig. 9,10 explanation workings of an invention.Decision is predicted the operation that operation is later and is created conditions as shown in figure 10.Perhaps, especially cold rolling forward part remove prediction as defective at the position of manifesting in the future.

By shown in Figure 9, carry out manifesting of the defective prediction operation of Figure 10 by skin section characteristic detecting apparatus 13 and manifesting of defective prediction unit 15.Said herein characteristic is meant the having or not of the abnormal portion different with other normal portion, kind and spatial distribution thereof.And the concrete example of " abnormal portion different with other normal portion " is as nip big concavo-convex, the crystallization particle diameter, grain properties unusual part, uneven components etc. of interface portion of basic steel layer, non-metallic inclusion, oxide skin and basic steel layer of, oxide skin.

At first the manufacturing process of steel band skin section characteristic and the selection of position are measured in explanation.When part is removed abnormal portion, produced characteristic variations owing to removing, therefore want not take place defective on the contrary, must make in the operation shape of steel band, characteristic even in the back in rolling grade, therefore, carry out the part of near-surface anomaly portion as far as possible in the upstream and remove, will before cold rolling, carry out at least.

And, in manufacturing process's conditional decision operation, not only feedover to such lower procedure, and output is used to determine also comprise to the steel band of after this making, next manufacturing sequential (manufacturing opportunity) and the next change of creating conditions of making the feedback of creating conditions of the steel band of making in batches just, perhaps the information that changes of operation.Like this, can predict whether manifesting of defective later on, can also determine creating conditions of steel band that (feedback) after this made thus in next operation in the future.

For example, when considering in early days when the operation feedback of generations abnormal portion reasons such as system steel operation is created conditions, hope is carried out the skin section characteristic measurement in the operation near upstream process as far as possible., must before removing near-surface anomaly portion, carry out for this reason, wish before cold rolling, to carry out at least the skin section characteristic measurement.

On the other hand, according to following reason, wish to carry out the skin section characteristic measurement later at hot-rolled process at least in the downstream as far as possible.

1) when detecting minor anomaly portion,

(a) for can not making detection efficiency, noise that concave-convex surface produces do not descend,

(b) for when sensor detects near steel strip surface, the distance of sensor and steel band (liftoff) change can not make detection efficiency worsen, and

(c) do not contact with steel band for liftoff change can not make sensor, can not make the sensor breakage, can not make the steel band damage,

Because above-mentioned (a) and (b), (c) reason, the steel plate shape must be good.

According to this point, the steel plate shape of lower procedure side has better tendency, and by applying tension force etc., the shape of lower procedure side is more stable.

2) reduce by rolling thickness of slab, abnormal portion detects when being present in from the surface as far as possible nearby thereupon easily.

3) also producing by rolling abnormal portion in the process of distortion, detecting, can more correctly carry out important evaluation from the near as far as possible stage of final finished.

According to above reason, when removing the skin section abnormal portion, the skin section characteristic detecting apparatus is set before should be after hot rolling cold rolling and part is removed device.And, when selecting creating conditions in addition, must be respectively every kind of situation be considered that the above-mentioned relevant item in position that is provided with decides the position is set.

For example, in the time must determining as the thickness of slab of creating conditions, then must before cold rolling, carry out the skin section characteristic measurement according to skin section characteristic measurement result.And, for example, for clad steel sheet, whether prediction punching press rear surface defective manifesting, mark is squeezed at the position of manifesting of defective after predictable punching press, not use in the operation afterwards, perhaps cuts away zone that is considered to steel band length direction defective pilosity etc., even when carrying out behind the plating also enforceable means, carry out the skin section characteristic measurement after also can being chosen in plating near final occupation mode.

In addition, about the selection that the position is set of skin section characteristic detecting apparatus, except that above-mentioned reason, also has following reason.

1), wishes that the amount of jitter of steel plate is little in order to detect, remove abnormal portion.

2), wish that line speed is not too fast in order to detect, remove abnormal portion.Hot rolling line outlet side etc. is very high speed, and is generally inapplicable.

3) produce smear metal etc. owing to remove operation, wish to have equipment easy to operate such as washing, drying, perhaps wish to be provided with easily.

About the above-mentioned the 1st) point, specifically,, b) wish that brute force applies tension force owing to a) wish to set up evener, therefore can be after evener, and on position, the skin section characteristic detecting apparatus is set with the face of the relative side of check surface of roller supporting and steel band.And, according to above-mentioned 2), 3) reason, if can be arranged on pickling lines entrance side (the tight front of pickling layer) then better.Because same reason, preferably remove device top layer characteristic abnormal portion being set with the same position of skin section characteristic detecting apparatus.

And, if at the unit tension of steel band at 0.3kgf/mm ²Above position is checked, because steel band becomes smooth, can not be subjected to steel plate deformed to carry out the good inspection of precision with influencing.

After measuring the skin section characteristic, in the operation afterwards, not only according to the measurement result of skin section characteristic, and additional straight to the actual value of creating conditions of carrying out the skin section characteristic measurement, predeterminedly in operation after this create conditions, the condition of the height association in the various conditions such as the specification of finished product (comprise the user of steel band, in the occupation mode of final consumption in the stage etc.) predicts, can predict whether manifesting of defective accurately.Specifically, comprise the various situations, punching press condition, application condition of steel grade, heat-treat condition, rolling condition, plating kind, other steel band manufacturing line, final occupation mode etc.

As shown in figure 12, defective or defective candidate are divided three classes.

(1) injurous defect A: the defective that behind the characteristic measurement that uses prediction unit to carry out, takes place

(2) injurous defect B: measuring with prediction unit, detecting in the position of signal, after the skin section characteristic measurement, be predicted as will manifesting as defective the mensuration position.

(3) normal portion: after surface characteristic is measured, be predicted as the mensuration position that does not manifest change.

Usually, injurous defect is checked the surface with surface defects detection instrument or artificial visually examine in final operation, with above-mentioned (1), (2) two as detected object.For these injurous defects, for example, when harmful degree is very big, cut off, excise whole positions of these defective part.And, in harmful degree is～when slight, in order to make in go out 1 volume of library unit as 1 of steel band, perhaps, in certain steel band long measure (for example, 500m or 1000m unit) number of defects that go up to exist in allowed band, and cut off, excise suitable defective part, be adjusted in the 1 coil band or the defective on every section unit length.And when the defective number did not drop in the allowed band, before delivery, change object-oriented or purposes reduced the finished product grade, outbound then.Therefore, these yield rates of operating defective not only are low, and in order to cut off, excise operation, must be transported to special-purpose inspection production line or cut off production line, the problem that exists cost to increase.And, when defective is too much, owing to can not determine zero defect in advance, steel band that can not outbound is carried out useless operations such as plating process, also produce cost.

Especially, in these defectives, what mainly handle as significant deficiency is the defective that abnormal operation produced in system steel operation or hot-rolled process, is equivalent to after being arranged on hot rolling and the injurous defect B of the Figure 12 when detecting of the surface characteristic determinator before cold rolling.Thereby, before final operation, if can know the existence of injurous defect B, then can change the later operation route of predetermined next operation (next operation → next operation → following next operation → ... → outbound → ... → steel band logistics the route that uses etc. to the user), perhaps change object-oriented as the user user of final finished delivery, change is created conditions, and can handle.Therefore, if predicted in the past in final operation that steel band is packed at least, manufacturing process's route can be set for do not carry out in the past up to the useless operation of finishing final finished or be used to remove the additional process of defective, the qualification rate of finished product not only can be improved, and manufacturing cost can be reduced simultaneously.

And, as previously mentioned, even the level of signal of skin section determinator is identical, when checking that the object steel band for example is hot-dip steel plate, electroplating steel plate or cold-rolled steel sheet, be used for automobile or be used for electronic product etc., when how changing as these modes of final finished outbound and use or condition, the defective of prediction becomes the injurous defect B of Figure 12, perhaps becomes harmless defective.At this moment because, for example, when plating, be present in defective on the former steel plate under the coating and become and be difficult to see, become sometimes on the contrary and see easily, same according to user's punching press shape or application condition, become easily sometimes and see, becoming sometimes on the contrary is difficult to see.Thereby, according to condition, during the injurous defect B of Figure 12 regional and become big, the time and diminish.And, in the judgement of prediction unit, not only judge at detected position one by one, and, also consider to be present in the defective integral body of the prediction in 1 volume or the unit length, for example the distribution of Yu Ce defect level and defects count, defective closeness etc. is judged.

As shown in Figure 9, utilize manufacturing information holding device 16 (generally can utilize process computer etc.), correspondence database 17 to provide these information to manifesting of defective prediction unit 15.Manufacturing information holding device 16 and each steel band are stored the information of creating conditions as coiled material sequence number, the kind of the steel band of skin section characteristic measurement object, the steel grade that is expressed as the branch characteristic, inspection condition, user or specification purposes etc. accordingly, and begin up to the skin section characteristic measurement, perhaps when manifesting of defective prediction processing begins, transmit these information to manifesting of defective prediction unit 15a, 15b.According to the detection signal of the skin section characteristic of skin section characteristic detecting apparatus 13a, 13b with from the information of the steel band of manufacturing information holding device 16 and the information of correspondence database 17, the blemish that manifesting of defective prediction unit 15a, 15b check each position of steel band that steel band information comprises manifesting whether in the final production line.For example, for coated steel strips, behind plating in the folding example of the squamous of manifesting as blemish, even identical skin section characteristic before cold rolling, according to kind (hot dip/plating, alloyed hot-dip (GA)/simple hot dip (GI), the individual layer plating/double-deck plating) difference of plating, whether manifesting creates a difference defective behind the plating.And even for the defective of manifesting when the punching press coated steel strips, because plating kind difference, therefore the differences such as sliding on surface during punching press can produce same difference.Thereby, in order to judge these difference, each signal of skin section characteristic detecting apparatus 13a, 13b must be corresponding in advance with the grade of the kind of the value of characteristic quantity and presentation surface defective and/or degree, the feature value for example is the size (length, width, thickness) that surpasses the abnormal portion of defined threshold, shape, depth location etc., and described blemish is in each operation finally manifesting and the defective that detected by blemish meter or people's visual inspection.Make skin section characteristic detecting apparatus signal with in each manufacturing process the mapping table of detected blemish format, with this information as file storage in correspondence database 17.Manufacturing process is the manufacturing line of CAL, CGL, EGL etc. for example.CAL is a continuous annealing production line, and CGL is the continuously dip coat production line, and EGL is an electroplating assembly line.In addition, this database, after measuring with skin section characteristic detecting apparatus 13a, 13b, in each manufacturing process, implement surface inspection, can collect each manufacturing process as a result the time, this result as in the inspection message input process computer as the manufacturing information holding device 16 of host computer, then, is sent in the correspondence database 17 and is stored in wherein.And the measurement result of manifesting prediction unit 13a, 13b also is sent in the correspondence database 17 via manufacturing information holding device 16 and is stored in wherein.The result of the result of so-called skin section characteristic detecting apparatus and the surface inspection of each operation utilizes the coiled material sequence number of steel band next corresponding with steel band, and carriage direction is not only considered in the position in the steel band, and considers rolling rolling rate, and carries out correspondence.Store measured signal and the surface inspection result of skin section characteristic detecting apparatus 13a, 13b one by one, upgrade correspondence table.Surface inspection result's data are not limited to the operation of final inspection steel band, when final middle operation is checked, also import its data, make correspondence table.And, according to this table, make the logic of the prediction judgement of manifesting of defective prediction unit 15a, 15b.Perhaps, also can make decision logic by the automatic Core Generators of logic such as data input neuron network with table.

And manifesting of defective prediction unit 15 is no problem in which manufacturing process by judging the forecasting object steel band, selects the operation route.This is predicted the outcome is sent to manufacturing information holding device 16, changes later steel band operation route.

At this moment, in user who is predetermined steel band or the specification purposes any one, also can be according to for example steel grade of creating conditions before manifesting of defective prediction unit 15a, the 15b, by a plurality of kinds, user, specification purposes as candidate, according to the prediction judged result, after the prediction judged result, select the logistics route of a steel band.Like this, according to the present invention, can formulate logistics route etc. flexibly.

Figure 13, Figure 14 show according to the program example that predicts the outcome decision manufacturing process, creates conditions.

For example shown in Figure 13, carry out the skin section characteristic measurement, be carried out to manifesting of the defective prediction of the condition of product kind 1.With measurement result be stored in above-mentioned correspondence database 17 in corresponding form data relatively, judge whether it is the skin section characteristic that is applicable to the degree of finished product kind 1.For example, not only qualified/underproof judgement is carried out at each skin section characteristic measurement position, and judged with regard to the number of the manifesting defective of per 1 coil band or unit length.For example, even manifesting of defective number is one, when defect level is predicted as severe, be judged as defective, degree by in when slight, in 1 volume or the number of per unit length when for example surpassing 5, be judged as defective.Make according to the condition of finished product kind 1 when qualified.When defective, carry out the prediction of manifesting of defective, judge whether it is the skin section characteristic that is applicable to the condition degree of finished product kind 2.Next, if the judgement that similarly predicts the outcome qualified then according to the condition manufacturing of finished product kind 2, if defective then carry out manifesting of the defective prediction of next kind, is so carried out processed in sequence.Like this, according to the change trimmed size that predicts the outcome, determine manufacturing process in view of the above, create conditions.This decision logic is set for by the finished product kind of standard strictness and is judged (with the finished product kind of standard strictness as finished product kind 1), when not being suitable for whole finished product kind class standard, is judged as the waste material that can not become finished product.

As concrete example, result according to surface characteristic mensuration, when implementing later manufacturing process with the alloyed hot-dip galvanized steel sheet of outside plate use as battle wagon, when prediction can be guaranteed sufficient quality, be rolled into automobile with suitable thickness of outside plate etc. stipulate manufacturing, and predict the outcome according to above-mentioned, when not being suitable for automobile with the outside plate alloyed hot-dip galvanized steel sheet, when prediction may be used as general material for building, change the user's that receives object-oriented, be rolled into corresponding therewith thickness of slab, not later the creating conditions and trimmed size (comprising object-oriented) of next operations such as clad steel sheet of alloying made in decision

And, change in addition in addition to judge as the object-oriented that the finished product kind changes or the user changes judgement the carrying out in proper order of Figure 13.For example, when the finished product outbound, because the relation of time of delivery has to be altered to product kind, OO situation.At this moment, as shown in figure 14, carry out the skin section characteristic measurement, carry out the prediction of manifesting of defective part, judge, make according to the condition of finished product kind 1 when qualified according to predicting the outcome with regard to finished product kind 1.According to measurement result, when the product of the characteristic that can not be present in finished product kind 1, perhaps when in 1 volume or the number in the unit length surpass and allow number to become when defective, decision can not be present in the defective position in the steel band in the length direction of steel band.Then, the defective position of excision steel band perhaps, makes it innoxious by grinding, handles according to predetermined after next operation.Like this, remove predicted manifesting of defective part, only make normal partial continuous at whole width, perhaps, can be innoxious by the periphery that makes manifesting of defective predicted portions, make it can become normal steel band.

Concrete example is, carries out above-mentioned predicting the outcome with the clad steel sheet manufacturing as prerequisite, when prediction will produce defective in certain zone of length direction of steel band behind plating, and the described zone that before plating, can excise steel band in advance.

The determination methods of manifesting of the defective prediction among the present invention is not only carried out the processing of Figure 13, Figure 14 independently, carries out but also can make up, and is not limited to processing based on Figure 13, Figure 14.

Fig. 8 is the key diagram of 1 example of embodiments of the present invention, in pickling lines, skin section characteristic detecting apparatus 13 is set after entrance side evener 11, by manifesting of defective prediction unit 15 prediction characteristic abnormal portion after operation in whether as manifesting of defective, utilize top layer characteristic abnormal portion to remove device 14 and therefrom determine to remove object portion, remove and comprise the zone that this removes object portion by the part means of removing.Fig. 1 of skin section characteristic detecting apparatus such as back～shown in Figure 6 can use that can precision to be determined at the C cross section well very small and at the rolling direction device of the characteristic of the surface characteristic abnormal portion of long shape.

Also comprise inscape, surrounding condition with steel band surfaces externally and internally correspondence, structure, action are described in detail.At first, utilize the evener 11 that is arranged on the pickling lines entrance side to reduce the concavo-convex of steel plate.Then, increase the tension force of steel plate, and, clip steel band 1 and remove device 14a (the steel band outside with), 14b (the steel band inboard is used) in the couple positioned opposite skin section characteristic detecting apparatus 13a of idler roller 12a～12d (the steel band outside with), 13b (steel band inboard with) and top layer characteristic abnormal portion in the position that is wound on major diameter idler roller 12a～12d.

In addition, outside defective manifesting prediction unit 15a and inboard manifesting of defective prediction unit 15b are set.At this moment,, thereby reduce liftoff change, be preferably in 0.3kgf/mm owing to suppress the shake of steel plate at the unit tension of the locational steel band that the skin section characteristic detecting apparatus is set ²More than.Inside and outside system move in theory independently, therefore later for the sake of simplicity, be applicable to the inboard too for the explanation in the outside.

Below, illustrate that at first skin section characteristic detecting apparatus 13a, manifesting of defective prediction unit 15a, top layer characteristic abnormal portion remove the main elemental motion of device 14a and relation each other.When estimating the skin section characteristic, mainly be conceived to also comprise size (rolling direction length, cross direction length, thickness), shape and the depth location of the abnormal portion under the steel plate top layer.

, can utilize as signal amplitude, phase place and Two dimensional Distribution thereof after the detection of measurement result data synchronization and estimate during in mode that adopt to use exchange flux as the characteristic measurement method.Phase place comprises the information about the depth location of characteristic abnormal portion.And, because by changing the excitation frequency of exchange flux, magnetic flux changes from the penetration depth of surface of steel plate, therefore utilize a plurality of excitation frequencies to measure, by the said determination result data, can obtain about having and the skin section of other parts different qualities details in the distribution (thickness, depth location etc.) of depth direction.

Owing to contacting of the liftoff change that has suppressed to cause or sensor and steel band, skin section characteristic detecting apparatus 13a is set on the position in above-mentioned production line by steel plate shake, steel plate deformed.Utilize skin section characteristic detecting apparatus 13a, the signal value of each measuring point on the steel band etc. is sent to manifesting of defective prediction unit 15a.When for example in foregoing invention, utilizing exchange flux to estimate the skin section characteristic, as the data that transmit, be not only the synchronous detection signal amplitude of above-mentioned each measuring point, also can comprise the synchronous detection phase place, and be not limited to a kind of at the excitation frequency of exchange flux and use when multiple, signal value, synchronous detection phase place also can only increase frequency number.

Utilize manifesting of defective prediction unit 15a, according to the information of skin section characteristic detecting apparatus 13a, estimate the skin section characteristic, prediction is in next operation is later, and whether the characteristic abnormal portion can manifesting as defective.

About the skin section evaluating characteristics, the example when the exchange flux that adopts foregoing invention is estimated the skin section characteristic is described below.Figure 11 is the figure that the prediction flow process of exchange flux is used in expression.The first, measure by the top layer of exchange flux enforcement and steel band two-dimensional coordinate correspondence.Two-dimensional coordinate is represented with length direction x (m), width y (m).Be captured in each point the synchronous detection amplitude A (x, y) and phase place P (x, data y).The second, the synchronous detection amplitude and the phase data of each point is sent to manifesting of defective prediction unit.The 3rd, mark surpasses the zone of certain threshold value.About the unusual instruction unit of adjacency, be familiar with as on the same group abnormal portion mutually, with this group unit " prediction " defective manifesting whether.For example, for the synchronous detection signal amplitude, set certain certain threshold value, disposable extraction has above the point of the two-dimensional coordinate on the steel band of the signal value of this value as abnormal portion candidate point.And, to each group identification abnormal portion candidate point (mark processing) separately, try to achieve separately characteristic quantity of 2 dimensional region (rolling direction length, cross direction length, area etc.) and thickness, synchronous detection phase information.Because the synchronous detection phase information is the amount of the depth direction position in reflected signal source, thereby, estimate as depth location information by obtaining phase place in advance to the conversion coefficient of the degree of depth etc.The 4th, based on the data of manifesting of the expression defective possibility of utilizing actual value in the past to obtain in advance, utilize characteristic quantity, depth location data to predict to each marked region.For example, depth location (can by phase estimating) less than certain certain threshold value, width greater than certain certain threshold value, synchronous detection amplitude during greater than certain certain threshold value, the prediction defective will manifesting.

And, when utilizing a plurality of frequencies to carry out AC excitation, when utilizing higher frequency to measure, more emphasize to measure characteristic abnormal portion, thereby can estimate in more detail the degree of depth near surface portion.

After hot rolling, measure the skin section characteristic before cold rolling, to carrying out alloyed hot-dip when handling, whether predict this determination part as manifesting of defective,, comprise the signal amplitude grade used behind the synchronous detection and the method for phase place as an object lesson of above-mentioned Forecasting Methodology.Can learn be positioned at than the position of certain depth as shallow that begins from the surface and have certain more than the certain value size in the long abnormal portion of rolling direction when plating is handled the back, will be as manifesting of blemish.Therefore, as Forecasting Methodology, as shown in figure 16, after obtaining from coiled material information as the manufacturing information holding device of host computer, exist level of signal more than defined threshold, perhaps has the above signal amplitude of certain certain value, and, the characteristic that has the length (perhaps according to circumstances also considering width, area, shape) more than the certain value in rolling direction is indicated unusually, when phase place is in the scope with above-mentioned abnormal portion depth location correspondence, dope as blemish will be after plating be handled manifesting.About the depth location of abnormal portion, because near more from the surface, operation afterwards is through rolling more easy manifesting, so degree is serious more.Add such information and threshold value be set decision in which operation can be used.For example, based on above-mentioned consideration, in depth location scope shown in Figure 15, judge and can or can not in CAL, CGL, EGL, use.CAL is a continuous annealing production line, and CGL is the continuously dip coat production line, and EGL is an electroplating assembly line.In Figure 16, depth location≤A means that defective is in the position more shallow than degree of depth A.The value of A, B, C, D be on the occasion of, dark more value is big more.Increased to the D value by A, the degree of depth deepens.

And, example as other prediction, what kind of synchronous detection amplitude levels research becomes blemish behind plating in advance position becomes in the pickling stage, if when the synchronous detection amplitude levels surpasses certain certain threshold value, to become blemish after being predicted as plating, when than threshold value hour, prediction can not become blemish, and then Forecasting Methodology itself becomes simple method.In addition, according to up to the target of predicting of creating conditions, actual value or predeterminedly after this create conditions, purposes or check that trimmed size such as specification selects threshold value, prediction algorithm.

According to from manifesting of defective prediction unit 15a remove characteristic abnormal portion position, object top layer (length direction, width, depth direction), top layer characteristic abnormal portion length information, top layer characteristic abnormal portion is removed device 14a and is removed the zone that comprises top layer characteristic abnormal portion by part grinding or cutting.In addition, stably carry out also in order to make top layer characteristic abnormal portion remove device 14a that top layer characteristic abnormal portion is removed and the checkout gear 13a of defective candidate portion is same, it is arranged on position in the little production line of steel plate shake, steel plate deformed influence.In addition, the sequential control of all moving by sequencer (not shown) etc.

The steel band of removing top layer characteristic abnormal portion is implemented plating through cold rolling, becomes coated steel strips.Like this, the part that becomes defective in next operation was removed in the pickling stage, and consequently, this coated steel strip blemish is considerably less, and quality is good.

The following describes several examples that are particularly suitable for skin section characteristic detecting apparatus of the present invention.Fig. 1 is the sketch (width differential mode) of the formation of expression skin section characteristic detecting apparatus.Be present on the steel plate 1 in the small top layer characteristic abnormal portion of growing at length direction (direction vertical) 2 of width with paper.Provide alternating current by excitation supply 3 to the coil of magnetizer 4, the skin section of steel plate 1 is concentrated magnetization.In the drawings, carry out preferably carrying out this magnetization as much as possible in the magnetization that forms magnetic flux towards the width of steel plate 1.

Blemish as above-mentioned clad steel sheet, in the arbitrary operation of each operation of final consumption, the defective of manifesting, when its occurrence cause is to make the nonmagnetic metal field trash that produces in the steel operation, perhaps be to sneak into steel when inner etc. when occurrence cause at system steel operation and hot-rolled process entrance side (before the hot rolling) oxide, in whole manufacturing process, it is generally acknowledged that origin is in the upstream process side, big rolling by carrying out via hot rolling subsequently, measure in the operation of characteristic in the present invention, extend to become (cross section when width cuts off steel band) very small, in the long shape of rolling direction in the C cross section.Therefore, in the present invention,, adopt the mode that is easy to measure this abnormal portion characteristic in view of the characteristics of this abnormal portion.

And, utilize two Magnetic Sensor 5a, 5b to detect the magnetic flux that is present in steel plate 1 outside.At this moment, because top layer characteristic abnormal portion 2 is present in Magnetic Sensor 5a below, because this top layer characteristic abnormal portion, magnetic flux or vortex flow be difficult to by, its result, than many with the detected magnetic flux of Magnetic Sensor 5b, the output of Magnetic Sensor 5a is greater than the output of Magnetic Sensor 5b with the detected magnetic flux of Magnetic Sensor 5a.

Therefore, these outputs are imported differential amplifier 6, and, when carrying out phase detection, obtain the signal corresponding with the size of top layer characteristic abnormal portion 2 by signal with excitation supply 3 synchronous waveform (having phase shift) with its output input phase wave detector 7.Should export and import top layer characteristic abnormal portion grade determining device 8,, can judge the grade of top layer characteristic abnormal portion 2 by comparing with predetermined threshold value.

Because skin section characteristic abnormal portion 2 is small and longer at length direction at the width of steel plate, if magnetize at the width of steel plate, it is big that the width that magnetic circuit is interdicted becomes, and obtains bigger top layer characteristic abnormal portion signal.And, because the width differential mode utilizes the differential wave of two sensor outputs to judge top layer characteristic abnormal portion, thereby common noise (variation of steel plate magnetic conductivity etc.) and external noise cancelled out each other on the sensor, can detect S/N than good top layer characteristic abnormal portion.

Figure 2 illustrates the primary structure (E type approach sensor) of skin section characteristic detecting apparatus.In following figure, provide identical label for the inscape identical with the inscape shown in the prior figures, omit its explanation.In this skin section characteristic detecting apparatus, use E molded lines circle 9 as magnetizer and Magnetic Sensor.The yoke of E molded lines circle 9 has three foot section 9a, 9b, 9c, all is arranged on steel plate 1 opposite side by side with the surperficial approximate vertical of steel plate 1 and the width of each comfortable steel plate 1 separately.

And, be supplied in from the alternating current of excitation supply 3 and be wound on the coil on the foot section 9a of center and magnetize.On foot section 9b, the 9c of both sides, also batched coil, as Magnetic Sensor.The magnetic flux that produces on the coil of foot section 9a passes through the near surface of steel plate 1, and returns foot section 9a by foot section 9b, the 9c of both sides.

At this moment, when top layer characteristic abnormal portion 2 is positioned at shown position, its magnetic resistance to the magnetic flux by foot section 9a, 9b is greater than the magnetic resistance to the flux by foot section 9a, 9c, and thus, the magnetic flux density of the flux by foot section 9b is less than the magnetic flux density by the magnetic flux of foot section 9c.Therefore, the voltage of responding on less than the coil that is being wound on the foot section 9c at the voltage of responding on the coil that is wound on the foot section 9b, when both being imported differential amplifier 7, output and both corresponding voltage of difference.

Should export and import phase detector 8, when carrying out phase detection, obtain the signal corresponding with the size of top layer characteristic abnormal portion 2 by signal with excitation supply 3 synchronous waveform (having phase shift).Should export and import skin section characteristic abnormal portion grade determining device 8,, can judge the grade of top layer characteristic abnormal portion 2 by comparing with predetermined threshold value.

E type approach sensor, by being arranged on width and above-mentioned width differential mode is same, the abnormal portion for extending in the steel plate length direction also can obtain bigger top layer characteristic abnormal portion signal.And because the cause of differential mode, the variation of magnetic conductivity etc. is cancelled out each other with external noise, can detect S/N than good top layer characteristic abnormal portion.

Figure 3 illustrates a part of structure (mechanical width scan mode) of skin section characteristic detecting apparatus.In this skin section characteristic detecting apparatus, by not shown magnetizing assembly, steel plate 1 at plate width direction by ac magnetization.Make Magnetic Sensor 5 in plate width direction scanning, the timeliness of observing its output changes.When having top layer characteristic abnormal portion 2, because the magnetic flux that detects in this part changes, the output of Magnetic Sensor changes, and therefore, handles by the output of Magnetic Sensor 5 being carried out signal, can detect top layer characteristic abnormal portion 2.When steel plate 1 when length direction is advanced, examination scope becomes the zigzag scope, if but the quantity that increases Magnetic Sensor is dwindled sweep limits, improve sweep speed, then can check out the top layer characteristic abnormal portion that specific length is above.

Figure 4 illustrates a part of structure (electron scanning mode) of skin section characteristic detecting apparatus.In this skin section characteristic detecting apparatus, by not shown magnetizing assembly, steel plate 1 at plate width direction by ac magnetization.In this skin section characteristic detecting apparatus, dispose a plurality of Magnetic Sensors 5 at the width of steel plate 1.The output of Magnetic Sensor 5 is connected on the scanner, signal is carried out in the output of a Magnetic Sensor of select progressively handle.Like this, can carry out with Fig. 3 in the electron scanning that is equal to of mechanical scanning.Owing to can scan at a high speed, can shorten the length direction length that to check out top layer characteristic abnormal portion.

In this skin section characteristic detecting apparatus, not the output of handling each Magnetic Sensor 5 one by one, and change by its timeliness and to check out top layer characteristic abnormal portion, also can import the output of adjacent per two Magnetic Sensors 5 one by one, the difference of these per two Magnetic Sensors of computing is checked out top layer characteristic abnormal portion by processing as described above.Like this, intersexuality ground is handled the code book body and is detected top layer characteristic abnormal portion when not required, can directly detect top layer characteristic abnormal portion by differential signal.

Figure 5 illustrates a part of structure (comb shape approach sensor) of implementing the skin section characteristic detecting apparatus.Because Fig. 5 mainly shows magnetizing assembly and Magnetic Sensor part, diagram steel plate and signal processing circuit have therefore been omitted.Configuration has each foot section of comb shape kicker magnet 10 of comb shape shape, makes it vertical with surface of steel plate and each comfortable steel plate width direction is arranged side by side.Coil is wound on each foot section.

In order to use this checkout gear to detect top layer characteristic abnormal portion, at first, shown in (a), use three foot section of figure left end, the coil of its central foot section 10b is connected with excitation supply 3, make this coil produce exchange flux.And utilization is wound on the foot section 10a, the coil on the 10c that are positioned at its both sides and detects described magnetic flux, and detection signal is imported differential amplifier 6, and following signal is handled and carried out with shown in Figure 2 the samely.This is equivalent to detect as E molded lines circle shown in Figure 2 with three foot section in the yoke left side of broach shape.

Then, electronics or electric commutation circuit shown in (b), begin to utilize the 2nd～4 foot section from left end, make the coil magnetization that is wound on the foot section 10c, and utilization is wound on the foot section 10b about it, the coil on the 10d detects magnetic flux.And, shown in figure (c), utilize three foot section on right side to carry out similar detection more one by one.

Below, repetitive operation is equivalent to make detector towards the steel plate width scanning direction, can needn't follow mechanical movement ground to scan across the width range of broad.Can carry out the switching of magnet exciting coil, magnetic test coil with electronic switch, also can switch by relay.

In addition, when sensors configured resembling Fig. 4, Fig. 5 or comb shape foot section, dispose one group of above sensor groups or comb shape kicker magnet, when each other sensor or comb shape foot section are configured to zigzag, can seamlessly detect top layer characteristic abnormal portion at width.In zigzag arrangement, also can dispose more than 2 groups according to the shape (also comprising the framework of sensor unit etc.) of sensor.In addition, in zigzag arrangement, want to make the signal between the sensor not interfere, must correspondingly adjust the electron scanning sequential between the approaching sensor.

In addition, why can obtain the oscillogram of Fig. 6 (b), be because in the top layer characteristic abnormal portion of plate width direction scanning rolling direction for the elongated shape on long limit.Shown in Fig. 7 (a), even in the elongated top layer characteristic abnormal portion of rolling direction scanning rolling direction, can not obtain Fig. 6 (b) shown in large-signal, can only obtain the little output shown in Fig. 7 (b).Therefore, be difficult to precision in rolling direction scanning and detect the elongated top layer characteristic abnormal portion of rolling direction well.

Claims (26)

1. the manufacture method of steel band or surface-treated steel strips has:

Steel disc is carried out hot rolling, make the hot-rolled process of hot rolled strip;

Measure the skin section characteristic of described steel band, obtain the characteristic measurement operation of measurement result;

In each operation of final consumption, whether the result who uses described skin section to measure predicts the position of measuring as manifesting of blemish, the prediction operation that obtains predicting the outcome after described characteristic measurement operation;

Predict the outcome according to described, determine later manufacturing process and the decision operation of creating conditions; With

According to the manufacturing process of decision and the manufacturing process of create conditions manufacturing steel band or surface-treated steel strips.

2. the manufacture method of steel band according to claim 1 or surface-treated steel strips also has according to described manufacturing process before described hot-rolled process and the operation of creating conditions and feeding back of predicting the outcome.

3. the manufacture method of steel band according to claim 1 or surface-treated steel strips, described prediction operation comprises: use described skin section measurement result, and use the target of creating conditions until the steel band of predicting, actual value, in predetermined the creating conditions, purposes, comprise the information that the information conduct more than at least a in the specification of the finished product of checking specification is used to predict of operation after this, whether the position that prediction is measured is predicted the outcome as manifesting of blemish.

4. the manufacture method of steel band according to claim 1 or surface-treated steel strips, described prediction operation comprises: utilize the information have with the distribution of the depth direction of the skin section of other parts different qualities to predict, predicted the outcome.

5. the manufacture method of steel band according to claim 1 or surface-treated steel strips, described decision operation comprises: according to the described later manufacturing process of decision that predicts the outcome, create conditions and trimmed size.

6. the manufacture method of steel band according to claim 1 or surface-treated steel strips, described prediction operation comprises: after described characteristic measurement operation in each manufacturing process that obtains final finished, whether the position that the result who uses described skin section to measure predicts mensuration from be predicted as defective will the part of manifest determine remove object portion as manifesting of blemish;

Described manufacturing process comprises: utilize part to remove device and remove and comprise described zone of removing object portion, then, carry out cold rolling to steel band.

7. the manufacture method of steel band according to claim 1 or surface-treated steel strips, described characteristic measurement operation comprises: make steel band measure face skin section ac magnetization, by measuring the variation that causes the exchange flux that produces by the skin section characteristic, measure the skin section characteristic of steel band.

8. the manufacture method of steel band according to claim 7 or surface-treated steel strips, described characteristic measurement operation comprises: be used in plural at least electromagnetic sensor that the general width direction of steel band is set up in parallel and detect the variation that is caused the exchange flux that produces by the skin section characteristic, based on the differential signal of the width of detection signal, measure the skin section characteristic of steel band.

9. the manufacture method of steel band according to claim 8 or surface-treated steel strips, described characteristic measurement operation comprises: relative with steel strip surface respectively and approximate vertical and and width of steel band direction almost parallel be set up in parallel 3 foot section of E type kicker magnet, apply alternating current to the primary winding that is wound on the central foot section, make the steel band excitation, secondary coil is wound on respectively on 2 foot section in the outside, based on the difference of the voltage of on secondary coil, responding to, measure the skin section characteristic of steel band.

10. the manufacture method of steel band according to claim 7 or surface-treated steel strips, described characteristic measurement operation comprises: make the steel band ac magnetization, make the width scanning of electromagnetic sensor at steel band, based on the variation of the electromagnetic sensor signal of following scanning to produce, measure the skin section characteristic of steel band.

11. the manufacture method of steel band according to claim 10 or surface-treated steel strips, described characteristic measurement operation comprises: make the steel band ac magnetization, electromagnetic sensor is mechanically moved in the width of steel band direction, and at the width of steel band scanning direction, based on the variation of the electromagnetic sensor signal of following scanning to produce, measure the skin section characteristic of steel band.

12. the manufacture method of steel band according to claim 10 or surface-treated steel strips, described characteristic measurement operation comprises: make the steel band ac magnetization, dispose a plurality of electromagnetic sensors in the width of steel band direction, switch the selection electromagnetic sensor by electronics, thereby carry out the width of steel band scanning direction, based on the variation of the electromagnetic sensor signal of following scanning to produce, measure the skin section characteristic of steel band.

13. the manufacture method of steel band according to claim 7 or surface-treated steel strips, described characteristic measurement operation comprises: and approximate vertical relative with steel strip surface and and the width almost parallel ground of steel band dispose the foot section more than 4 of comb shape kicker magnet side by side, wherein, coil is wound on the foot section of comb shape kicker magnet, the selection that timeliness ground switches the group of 3 adjacent foot section, and in 3 foot section selecting, apply alternating current to the primary winding that is wound on the central foot section, carry out excitation, secondary coil is wound on respectively on 2 foot section in the outside, based on the differential signal of the voltage of on secondary coil, responding to, measure the skin section characteristic of steel band.

14. the manufacture method of steel band according to claim 7 or surface-treated steel strips, described characteristic measurement operation comprises: under the dc magnetization grade of steel band excitation is essentially near zero state, the frequency that makes ac magnetization is in the scope of 100kHz to 10MHz and make steel band measure face skin section ac magnetization, by measuring the variation that causes the exchange flux that produces by the skin section characteristic, measure the skin section characteristic of steel band.

15. the manufacture method of steel band according to claim 1 or surface-treated steel strips in the final outbound of the steel band stage, also has:

Measure the skin section characteristic measurement operation of steel band skin section characteristic;

Only measure the surface characteristic of steel strip surface characteristic and measure operation;

Use described skin section measurement result and surface characteristic measurement result to predict after this in each operation of final consumption, this determination part as the blemish of the quality problems prediction operation of the manifesting of defective of manifesting whether;

According to the described manufacturing process's conditional decision operation that predicts the outcome decision manufacturing process and create conditions.

16. the manufacture method of steel band or surface-treated steel strips has:

Steel disc is carried out hot rolling, make the hot-rolled process of hot rolled strip;

In the AC excitation of carrying out steel band,, detect the detection operation that is included in the defective candidate in the steel band by detecting the variation that causes the exchange flux that produces by defective;

In by the detected defective candidate of described detection operation, will serve as the top layer or the decision operation of blemish candidate decision of the elongated shape on long limit with the rolling direction of described steel band for removing object;

Select comprising, and carry out the operation of removing of grinding or cutting by the zone of removing object of described decision operation decision.

17. the manufacture method of steel band according to claim 16 or surface-treated steel strips, described detection operation comprises: make the steel band ac magnetization, utilization detects magnetic flux at the electromagnetic sensor more than 2 that steel band general width direction is set up in parallel, and detects defective based on the differential signal of the width of detection signal.

18. the manufacture method of steel band according to claim 16 or surface-treated steel strips, described detection operation comprises: relative with steel strip surface respectively and approximate vertical and and width of steel band direction almost parallel be set up in parallel 3 foot section of E type kicker magnet, apply alternating current to the primary winding that is wound on the central foot section, make the steel band excitation, secondary coil is wound on respectively on 2 foot section in the outside, the difference of the voltage that will respond on secondary coil is as described differential signal, based on this differential signal, detect defective.

19. the manufacture method of steel band according to claim 16 or surface-treated steel strips, described detection operation comprises: make the steel band ac magnetization, make the width scanning of electromagnetic sensor at steel band, the variation based on the electromagnetic sensor signal of following scanning to produce detects defective.

20. the manufacture method of steel band according to claim 19 or surface-treated steel strips, described detection operation comprises: the relativeness of the signal waveform of the electromagnetic sensor during measured tiny flaw and the signal of actual measurement detects defective.

21. the manufacture method of steel band according to claim 19 or surface-treated steel strips, described detection operation comprises: make the steel band ac magnetization, by electromagnetic sensor is mechanically moved in the width of steel band direction, make electromagnetic sensor at the width of steel band scanning direction, variation based on the electromagnetic sensor signal of following scanning to produce detects defective.

22. the manufacture method of steel band according to claim 19 or surface-treated steel strips, described detection operation comprises: make the steel band ac magnetization, dispose a plurality of electromagnetic sensors in the width of steel band direction, switch the selection electromagnetic sensor by electronics, make electromagnetic sensor at the width of steel band scanning direction, variation based on the electromagnetic sensor signal of following scanning to produce detects defective.

23. the manufacture method of steel band according to claim 16 or surface-treated steel strips, described detection operation comprises: and approximate vertical relative with steel strip surface and and the width almost parallel ground of steel band dispose the foot section more than 4 of comb shape kicker magnet side by side, wherein coil is wound on the foot section of comb shape kicker magnet, the selection that timeliness ground switches the group of 3 adjacent foot section, and in 3 foot section selecting, apply alternating current and carry out excitation to being wound on primary winding on the central foot section, secondary coil is wound on respectively on 2 foot section in the outside, differential signal based on the voltage of responding on secondary coil detects defective.

24. the manufacture method of steel band according to claim 16 or surface-treated steel strips, described detection operation comprises: under the dc magnetization grade of steel band excitation is essentially near zero state, the frequency that makes ac magnetization is in the scope of 100kHz to 10MHz and carry out the AC excitation of steel band, simultaneously, by detecting the variation that causes the exchange flux that produces by defective, detect the defective candidate that is included in the steel band.

25. the manufacture method of steel band according to claim 16 or surface-treated steel strips, comprise: after evener, on the position of the opposite face of face of removing with roller supporting and check surface or defective of steel band, implement described defects detection operation, defective is removed at least one side in the operation.

26. the manufacture method of steel band according to claim 25 or surface-treated steel strips, described defects detection operation comprises: the unit tension at steel band is 0.3kgf/mm ²Detect defective on the above position.

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