WO1979000592A1

WO1979000592A1 - Method and apparatus for indicating and eliminating defects on metal slabs

Info

Publication number: WO1979000592A1
Application number: PCT/EP1979/000009
Authority: WO
Inventors: P Karlsson
Original assignee: Ssab Svenskt Stal Ab; P Karlsson
Priority date: 1978-02-06
Filing date: 1979-02-06
Publication date: 1979-08-23
Also published as: SE7801369L; DE2934886D2; GB2035853A; NL7900751A; FI790266A; JPS55500087A; DK47779A; BE873928A; NO790343L; IT1188753B; IT7909335A0; FR2416081A1

Abstract

Method and apparatus for determining and possibly eliminating defects on metal slabs, whereby at least the upper and lower sides of the slab are subdivided into different areas by means of a bi-dimensional system of coordinates. The maximum depth of defects is determined for each area by using at least one device finding the defects, and the data obtained are stored in a memory. Facilities are provided for eliminating the defects by processing, or for eliminating a defective part of a slab or an entire slab as scrap-iron. These facilities are operated on the basis of the maximum depth of defects of each area and slabs which are partially or partially discarded as scrap-iron are replaced by new slabs in view of the rolling program selected. The slabs from which defective parts have been removed are fed back to the rolling process as new slabs.

Description

Method and device for displaying and removing defects in metallic slabs

To identify the need ^'to methods, all flaws to be metallized rule slabs and to eliminate, had a number of proposals for the sequence which have led, particularly in letz¬ ter time to process, the proper determination of - the errors of - in particular Enabling external surfaces, not only in two dimensions, but also in terms of depth. For example, GB-PS 1 517 775 and 1 518 994 describe methods and a device for identifying and registering such errors, the errors being removed with the aid of registered values.

The object of the present invention is to provide a method and a device which can be to treat metallic slabs from the unprocessed state to the perfect state with total automation of all processes.

The method according to the present invention preferably includes the following steps, among others:

a) Determination of gross material defects on the slab (as the first sorting stage)

b) conditioning of the slab, i.e. Cleaning, descaling, removing the cutting edge and / or so-called cutting slag etc.

c) determine the slab designation while storing it in the process computer

d) Perform length and width measurements and, if necessary, also thickness measurements with simultaneous registration

e) the crack test e.g. carry out according to the above patent application

f) to switch on a second sorting stage, for example separating slabs which are not to be further processed (error-free) both from those slabs which are subject to defects which can still be removed and from those slabs which are partially or completely ver¬ must be scraped g) perform the data treatment of the registered impulses obtained, by means of which the control of error removal systems, such as grinding, flame, milling, chip-cutting machines or the like, is possible, or of devices for filling holes and cracks.

On the basis of the errors found, the slab can be processed or a defective section of a slab or an entire slab can be removed as scrap and the slabs which have been partially or completely removed as scrap can be replaced by new slabs, taking into account the desired rolling program , and smaller slabs are newly introduced by cut-off sections.

The invention is explained in more detail below with the aid of schematic drawings using examples.

1 shows in block diagram form part of a material and signal flow diagram for machines, for control devices for machines and for process computers up to the first sorting, i.e. without error removal machines.

FIG. 2 shows the continuation in the same block diagram form as in FIG. 1 until the finished machined steel slabs are loaded.

3 shows in block diagram form the various signal streams on test machines with the organs for receiving signals and for the process computer.

Fig. 4 shows in block diagram form a process computer for controlling a slab grinding machine.

Fig. 5 shows in block diagram form a process computer for controlling a flaming machine.

Fig. 6 shows a side view, partly in section, a

Calibration device for a surface inspection device

FIG. 7 shows the calibration device according to FIG. 6 in plan view

FIG. 8 shows a plan view of part of a test plate and FIG. 9 shows a section through the test plate according to FIG. 8 along the line c-c.

OMPI Any unprocessed metallic slab that is to be subjected to a further plastic treatment, such as by rolling or forging, must be freed from such defects as completely as possible before further processing, which could result in defects in the finished product. In order to be able to eliminate these errors, however, they must first be discovered.

The chain of operations, from the investigation of the slab, finding - Mark - Register and removing the error is in the ^* general "testing and treatment Putz¬" called.

For accurate and extensive planning, it is of the utmost importance to know the correct size, the static condition, the net slab weight etc. before the final rolling can be planned. The sooner you get this definitive data, the fewer slabs need to be in circulation. This also applies to so-called "lost" slabs.

It is also extremely important that the throughput time in the inspection and cleaning treatment is as short as possible and that the quality obtained in this way has the high and uniform class required by a faultless end product. The method according to the present invention and the associated device meet these claims.

If a slab is to pass through the inspection and cleaning system according to this invention, it is first identified either visually with a television camera or automatically by a license plate reader. This reading can take place at any place or at a first transport device in the line. Blocks 1 and 2 in Fig. 1 show such transport devices. In addition to the slab number, it must also be determined which is the top (e.g. 1) and which is the bottom (e.g. 2). The top can also be indicated or indicated using e.g. certain color marking. This slab number as well as the side (e.g. 12 or 21) is put into the process computer 40. This calculator should have a large memory capacity. At the beginning of the transport device (for example a roller table) 2 there is the station 3 for cleaning the slab of snow and ice, scale, mill cut edges or slag. The cleaning of the scale and the rolled skin can e.g. with a descaling machine. At station 4 there is a check for internal defects such as cavities, for lamination, segregation, slag or other serious inclusions. This test can e.g. be carried out by means of X-rays and / or ultrasound.

'BURE OMP ^' V- 'WIP The internal condition of the slab is evaluated and the values are stored in the process computer 40 together with the aforementioned slab number. If the slab is to leave ^* at this stage, it can be lifted directly from the transport device or transported to station 18 without any further measures.

Block 5 represents a transport device for slabs, which can be assembled, for example, with an automatic ^* length * or width measuring device 6. It can also be advantageous to measure the thickness of the slab at the same time.

This measurement can also be used to check whether the slab in question has the correct dimensions or whether the correct slab number has been read. However, this dimension measurement is primarily necessary in order to be able to determine the number of test heads that are to take part in the subsequent test for cracks. This is particularly important if the vertical long sides are also to be checked. The values obtained are stored in the process computer 40 for each slab.

Block 7 represents a transport device for slabs in connection with a first testing machine 10. The transport device can be, for example, a roller table, a chain conveyor or a chain towing system. The number and side of a slab on the transport device 7 is read off and these values are entered into a process computer 35 suitable for the test. The latter has received all the required size data from the computer 40 at the same time. If the slab is not to be checked, a message appears on a data screen or a written message (documentation block 36a, connected to the computer 35). The machine 10 can also be blocked.

The operation of machines 10 and 15 is described in GB-PS 1 517 7 and GB-PS 1 518 994. Values obtained are stored in the calculator until the (upper) slab side has been completely checked. The examination documents can be obtained from 36a. When one of the preceding along vertical sides to be tested, _t one obtains the result which is stored in the computer 35, at the same time.

In anticipation of the results from testing the opposite side (s) in a second test device 15, e.g. the data obtained first are recorded in the computer 35 in order to be combined with the data received in the second test device 15 when this test is completed. Then the data can e.g. can be entered into the disk memory of the computer 40. If a long time passes between these exams, it can

OMPΪ

&;? NATlO however, it may be advantageous to continuously enter the error messages received into the computer 40.

In the test devices 1Q and 15 there are devices 8 and 13, respectively, which bring the slab into position with respect to the coordinates X ==, Y = 0 and Z = 0 or bring the test device 10 and 15 into position with the slab, e.g. in the form of mechanical, electrical, electronic and / or optical positioning devices so that at the start of the test this happens with the starting point of X = 0, Y = 0, Z = 0.

Furthermore, a device 9 for calibrating the test heads is provided on the machine 10, which is described in more detail in FIGS. 6 to 9. It is extremely important that each individual test head can be calibrated and checked continuously.

Block 11 represents a slab turner in which the slab is turned before the subsequent test.

Blocks 12, 13, 14 and 15 correspond to the aforementioned blocks 7, 8, 9 and 10.

After checking the two horizontal sides and - if necessary - also the two vertical sides, the slab is transported further, namely via the transport device 16 to a sorting device 17. The fault-free items are identified therein Slabs sorted out and stacked in block 21 for loading. Slabs on which serious errors have been found are sorted out to the control station 18, where these errors are examined in more detail. There it is determined whether the bra me can be cleaned after removing the errors or the most serious errors while maintaining the original dimension. If the slab is judged to be scrap, it can be stored in a scrap station (block 19) until it is transported to the scrap yard. If the slab can be used after certain errors have been eliminated, it is returned to the line. All fault data with specified coordinates can be made possible, for example, via a data screen or the most serious fault locations. If measures are taken against certain error locations, this is to be reported to the computer 40, which removes these errors from stored error registers.

If the slab has to be cut at the control station 18, this as well as the new dimensions will be reported. This enables rescheduling for the remaining pieces. These then get new numbers. The slab or slabs can then be unloaded at station 20 in order to be placed in the test and cleaning chain again.

<__ »

Block 22 represents a transport device that such

- O PI Carried slabs that are to be processed further with regard to surface defects. Switch machine - this treatment is to be carried out is determined at the sorting station 17. Slabs, the flat. Tie enf.eh.ler can advantageously be planned in, for example, a grinding machine, which is represented by block 23, while deeper errors are preferably eliminated in flaming machines at, for example, blocks 24 and 25. If the slab material is not suitable for flaming, other methods can be used in addition to grinding.

The time that is necessary to remove the defects on each slab, including turning, can theoretically be calculated by the computer 40, based on the data obtained for the depth and length of the defect and the type of machine. These values are used partly to direct the slabs to the different machines and partly to calculate the machine staff etc.

Block 27 represents a device on the machine which is required to bring the slab or the machine into X = 0, Y = 0, Z = 0 or in other words into such a zero position which was determined during the test .

Block 26 represents a slab turner which, depending on the final machine layout for e.g. two error removal

IjUREAtT

OMPI «τ machines can be common.

The flaming machines 24 and 25 can have one or more burners. In the case of a version with multiple burners, the removal can either be carried out according to the Swedish patent 199605 (Uni Carbide) or the burners can be attached at a certain distance from one another (safety factor). S can also be controlled so that the ignition of 2 burners next to each other is avoided.

As already noted at the beginning, the Swedish patent application 7507210-8 describes a method by which the identification and registration of errors is possible and that the values obtained are used in the machines which are intended to eliminate the errors. In this patent application it is not stated which signal current is obtained during the test and how the control elements are to be designed in order to receive and control the various fault removal machines according to the method mentioned in the patent application. As an example, two generally occurring machines, two flaming machines and one testing and cleaning machine have been chosen. No modern machine of this type is known in modern technology, which can be controlled fully automatically and which can remove three-dimensional defects from the slab surface.

^' BÜ EÄ

_ OMPI 2 blocks 37, 38 and 39 represent the control elements (process computers) which are required for the automatic removal of errors. The main units that must be present in such an organ and the control program are shown in the block diagram form according to FIG.

The corresponding control element for a testing and cleaning machine is shown in the block diagram form according to FIG. 4.

Input and output signals as well as the control element for a testing machine result from FIG. 3. Block 34 consists of the signal reception and the signal conversion as well as the element for the classification of errors in depth order.

After the slabs have been completely freed from the previously determined errors, they are conveyed on via the transport device 28. There is a scale 29 in this. The new weight is passed to the computer 40.

Block 30 represents a sorting device in which the slabs are sorted, according to the excluding rolling program.

Blocks 31, 32 and 33 are represented by stacking compartments for the following transport. Calibration devices 9, 14 are preferably provided for checking the functionality and for adjusting and calibrating the test devices 10, 15, for the non-destructive electrical, magnetic and / or magnetic inductive testing of metal slabs having different electrical and / or magnetic parameters, in particular steel slabs, on flaws, such as cracks, top rolls, blowholes, bubbles or the like located on or near the surface: The slabs are conveyed by means of transport devices 7, 12, which preferably consist of transport rollers arranged at a distance from one another Area of the test device 10 or 15 is transported and one or more test plates simulating a metallic slab with defects and having their electrical and / or magnetic parameters are arranged in a position approximately aligned with the surface of the slab to be tested and the Test organs 10 'of the test device direction 10 or 15 on the surface of the test plate or test plates and / or the surface of a test plate holder aligned with the test plate surface are brought into contact and checked for functionality when the test plate or test plates are run over. The test plates are preferably arranged to the side of the path of movement along which the slabs move on the transport device in such a way that the Test organs of the test device preferably move immediately before and / or immediately after their movement, which serves to search for defects, along the surface of the slab to be tested, which moves over the test plates.

Alternatively, the test plate or plates of the calibration device can be introduced into the transport path of the slabs in the transport device, preferably between two transport rollers, approximately flush with the surface of the slab to be tested, and can be removed again after the test plates have been moved over by means of the test organs the movement path of the slab, preferably downwards and / or to the side.

The calibration arrangement 9 shown in FIGS. 6 and 7 has a magazine M containing a plurality of test plates T and has a chain conveyor K with at least two chain conveyor belts composed of individual links, each of which is driven by a gear motor 105 and on a shaft 106 mounted drive wheel 107 are cyclically movable. The test plates T are fastened on the chain links 104 of the conveyor belts. The top of the test plate magazines M has a right and a left support base 108 and 109 for the test heads 10 'of the slab test

Device 10. These support bases are arranged such that they leave a gap between them in the aligned with the surface 112 of the support base 108, 109, the desired test plate T can be inserted.

In order to be able to adapt the position of the surface 112 of the support bases 108 and 109 of the test plate T exactly to the thickness of the slab B to be tested in each case, the entire test plate magazine M can be raised and lowered by means not shown, as shown in broken lines in FIG. 1. The left support base 109 forms on its left outer side 113 a lateral stop for the slab B to be tested after checking and calibrating the test device 10 by moving the same to the left, the transport device 7 having the rollers in the direction perpendicular to the plane of the drawing and by means not shown , on the side surface of the slab B facing away from the stop 113 and in the direction of the arrows 100 in the direction of the arrows 100 can be moved in contact with the stop 113. The slab B is moved and checked transversely to the conveying direction of the transport device 7 by means of the test heads 10 '.

As can be seen in particular from FIGS. 8 and 9, the test plate T is rectangular as a bar corresponding in its length approximately to the length of the slab to be tested or the width of the test device 10. In the ^" surface of the test plate T, approximately at the same distance in which the test heads 10 'are arranged from one another, at right angles to the longitudinal direction of the test plate T, several rows 140 of narrow indentations or slots 141a to 141d are provided, which are acute-angled, lower - OMPI extend right and parallel to the direction of travel of the test heads 10 '. In the illustrated embodiment, 141a to 141d are incorporated into the test plate T in a different manner, but in each group 140 with the same orientation, in such a way that the three slots of each group have different depths

The test device is preferably designed in accordance with GB-PS 1 517 775 and the errors determined are divided into several depth classes. In this case, it is expedient to assign two slots to each boundary between two depth classes, of which one slot has a depth which is a certain percentage below this limit and the depth of the other slot is approximately the same percentage above this limit , the percentage being approximately equal to the measuring accuracy of the testing device, but preferably slightly greater than this measuring accuracy. The correct classification of the errors simulated by such slits in the depth classes of the test device can be checked automatically by the sequence of the depth classes shown when the test plate is driven over in a computer, for example. B. the computer 35 is programmed and deviations from this sequence are displayed by means of this computer 35 via 34 and 34 'at 10 and 15, respectively. ^* - - Preferably, the slots are arranged along the rows of the test plate at distances which are dimensioned such that the slots do not overlap in the direction of the rows. The length of the individual slots is preferably selected to be at least equal to the diameter of the test coils present in the test heads 10 ', for example 40 or 60 mm.

The exact height adjustment of the test plates to the level of the surface of the respective slab B to be tested is preferably carried out by means of photocells which enable automatic working and e.g. 6 and 7 in the area of the stop 113 of the support base 109 can be installed just below the surface 112, by means of a side of the slab B facing away from the stop 113 at the same height as the photocell a light beam is directed onto the photocell with the holder 109 arranged to move up and down. Push buttons can also be used instead of the photocells.

O

Claims

-Patent claims

1. Method for the determination and possible removal of defects in metallic slabs, at least the upper and lower. Flat side of the slab is divided into partial coordinate areas with the aid of a two-dimensional coordinate system and that the maximum error depth for each partial coordinate area is determined by means of at least one error determination device and that the data is stored in a data storage device, whereby processing devices for removal: the errors are used, which eliminate the errors by flame, grinding, milling, planing and / or other machining and / or local material replacement with simultaneous control of the processing systems on the basis of both the coordinates of the sub-areas of the above-mentioned coordinate system and in part the stored maximum error depths, characterized in that the slabs are fed into a computer with the aid of a number or a similar identification of the slabs with their dimensions and / or their weight before di e troubleshooting begins and that

is taken eine..notwendige on the basis of detected errors Bear¬ processing of the slab or removal of a section of a slab or an entire slab as _^ vorge scrap and in that the partially or completely precipitated as scrap slabs with new slabs

OMPI IIPPOO are replaced, taking into account the desired rolling program, and smaller slabs are newly introduced by cutting off sections.

2. The method according to claim 1, characterized g e k e n n ¬ z e i c h n e t that defects that are on or near the surface by means of eddy current methods and that defects that are located inside the slab are detected by ultrasound.

3. Arrangement for carrying out the method according to one or more of claims 1 and 2, characterized in that the arrangement for the description and / or determination of the individuality of the slab, for the determination of the errors which occur on or in the Are close to the surface or from defects that are located inside the slab (blowholes) and are arranged in a data-controlled "line" to remove the defects.