Claims:We claim:
1. A method of measuring an area of a roll groove (202a) of a roll pass (202) of a bar rolling mill, the method comprising:
marking a straight line across an outer rolling edge of the roll pass (202), wherein the straight line being parallel to axis of the roll pass (202) and covers the roll groove (202a) of the roll pass (202);
applying a measuring medium (204) over the marked straight line on the roll pass and allowing the measuring medium (204) to set and harden for a predefined time;
removing the hardened measuring medium (204) from the roll pass (202) and tracing the impression of a roll groove profile acquired by the measuring medium (204) on a recording medium (208);
measuring, by a processing resource, a fresh pass area of the roll groove (202a) based on the acquired roll groove profile.
2. The method as claimed in claim 1, wherein the measuring of the fresh pass area is performed by a processing resource, and wherien the processing resource is combination of hardware and programmable instructions.
3. The method as claimed in claim 1, wherein the measuring medium (204) is an epoxy agent which hardens after the predefined time.
4. The method as claimed in claim 3, wherein the epoxy agent is a multipurpose sealant.
5. The method as claimed in claim 3, wherein the predefined time ranges from 4-6 hours for the measuring medium (204) being the epoxy agent.
6. The method as claimed in claim 1, wherein the measuring medium (204) is a processed wet cotton cloth piece, and wherein the processed wet cotton cloth piece is obtained by:
dipping a cotton cloth piece in a starch solution for a specified time period;
removing the cotton cloth piece from the starch solution; and
sprinkling acetone on the cotton cloth piece.
7. The method as claimed in claim 6, wherein after applying the processed wet cotton cloth piece over the marked straight line on the roll pass, the method comprising drying the processed wet cotton cloth piece using a drier to reduce the time of hardening of the processed wet cotton cloth piece.
8. The method as claimed in claim 6, wherein the specified time period is 1 minute.
9. The method as claimed in claim 6, wherein the predefined time ranges from 5-10 minutes for the measuring medium (204) being the processed wet cotton cloth piece.
10. The method as claimed in claim 1, comprising applying lubricant on the marked straight line on the roll pass (202) before applying the measuring medium (204).
11. The method as claimed in claim 1, wherein the measuring of the fresh pass area is performed by marking a straight line on top of the acquired roll groove profile so as to create the fresh pass area of the groove profile.
12. The method as claimed in claim 11, comprising shading the fresh pass area of the groove profile for precise measurement of the area of the roll groove (202a) by the processing resource.
13. The method as claimed in claim 1, wherein after completion of each roll milling cycle:
measuring, by the processing resource, a mill out area of the roll groove (202a) based on the acquired roll groove profile; and
comparing, by the processing resource, the fresh pass area with the mill out area, so as to estimate the wear in the roll pass.
14. The method as claimed in 1, wherein the method is implemented using robotic arms coupled to a computing device embedded with audio and video devices.
15. The method as claimed in claim 1, wherein the recording medium (20) is one of a blank paper, tracing paper, blotting paper, printing paper, handmade paper, drawing paper.
, Description:METHOD OF MEASURING AREA OF ROLL PASS
TECHNICAL FIELD
[0001] The present disclosure described herein, in general, relates to estimation of the wear in a roll pass so that corrective measures can be taken. In particular, the present disclosure relates to a method of measuring an area of a roll groove of a roll pass of a bar rolling mill.
BACKGROUND
[0002] Background description includes information that may be useful in understanding the present disclosure. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed subject matter, or that any publication specifically or implicitly referenced is prior art.
[0003] Rolling is a metal forming process in which metal stock is passed through one or more pairs of rolls to reduce the thickness and to make the thickness uniform Rolling is the most widely used metal forming process. It is employed to convert metal ingots to simple stock members like blooms, billets, slabs, sheets, plates, strips, etc. The metal is plastically deformed by passing it between rollers rotating in opposite direction. The main objective of rolling is to decrease the thickness of the metal. Ordinarily, there is a negligible increase in width, so that the decrease in thickness results in an increase in length. Rolling is classified as hot rolling and cold rolling according to the temperature of the metal rolled.
[0004] In rolling, roll performance is commonly evaluated by measurements including total tonnage rolled, tonnage rolled per campaign, tonnage rolled per inch or mm of roll consumption, or specific roll force (force per unit width). During rolling, rolls are highly susceptible to damage from a variety of failure modes, including spalling, breakage, cracking, fatigue, wear, surface roughening, impression marks, bruising, hardness variation, or expression marks. The type of failure depends on certain parameters or operating conditions like mill operation, rolling schedule, mill equipment condition, practices and procedures, product type and chemistry, roll inspection methods, roll maintenance procedures, roll use practices and roll inventory. Out of these failures, wear is quite a common phenomenon. Due to prevalent of such defects or damages like wear, quality of workpiece gets affected along with its desired dimensions, productivity decreases, machining cost increases and so on. Conditions in groove rolling are clearly more severe when compared with the rolling of flat sections. The diversity in temperature, pressure and stress fields, along with slip gradient in calibre rolling result in accelerated wear of grooved rolls.
[0005] Therefore, detection of these damages or defects on the roll pass is required in order to mitigate or overcome the above-mentioned consequences of the damages. There are several methods available to measure the wear of the roll groove of a bar milling roll. One such method involves the use of laser technology. In this method, a laser beam profiler captures the image of the profile of the groove of a fresh roll pass and the used roll pass and generates the profile on a liquid crystal display (LCD) screen or a computer using a software. By calculating the area of the generated profile of the roll groove before its operation or when it is unused and after the operation of the roll pass or when it has been brought under operation, the amount of wear can be estimated or compared and then suitable corrective measures can be taken in order to carry the operation of rolling smooth and produce good quality workpiece. However, such a method using laser beam profiler is very expensive.
[0006] Another known method is available where a soft metal such as aluminium is used for offline rolling and taking the impression of the cross-section of the roll groove when it is not used or is freshly manufactured and when it has been brought under application so that amount of wear can be estimated by comparing the area of the cross-section made on the aluminium metal. But this method is tiresome and lengthy. Further, the chances of occurrence of an error are high in this method.
[0007] Yet another known method exists to estimate the wear in the roll groove. The method involves taking the impression of the worn roll groove by using plaster of Paris (PoP), putty or LC wire individually. However, the problem with each of the material used in the method is that PoP gets brittle after drying, putty takes a long time to set and is thicker and with LC wire chances of spring back action prevails.
[0008] In view of the above, there is a need to have a method which takes less time and is error free. Therefore, there is a need in the art to provide a method which is simple and inexpensive yet effective to replace the existing methods and thereby eliminate the existing above mentioned problems or drawbacks.

OBJECTS OF THE DISCLOSURE
[0009] Some of the objects of the present disclosure, which at least one embodiment herein satisfy, are listed hereinbelow.
[0010] It is a general object of the present disclosure to provide a method of measuring an area of a roll groove of a roll pass of a bar rolling mill which is less time consuming.
[0011] It is another object of the present disclosure to provide a method of measuring an area of a roll groove which provides accurate or precise results.
[0012] It is another object of the present disclosure to provide a method of measuring an area of a roll groove which is simple and cheap or economical.
[0013] These and other objects and advantages will become more apparent when reference is made to the following description and accompanying drawings.

SUMMARY
[0014] This summary is provided to introduce concepts related to a method for measuring an area of a roll groove of a roll pass of a bar rolling mill. The concepts are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
[0015] The subject matter disclosed herein relates to a method of measuring an area of a roll groove of a roll pass of a bar rolling mill. The method comprises marking a straight line across an outer rolling edge of the roll pass, wherein the straight line is parallel to axis of the roll pass and covers the roll groove of the roll pass. Then applying a measuring medium over the marked straight line on the roll pass and allowing the measuring medium to set and get harden for a predefined time. After that removing the hardened measuring medium from the roll pass and tracing the impression of a roll groove profile acquired by the measuring medium on a recording medium and measuring a fresh pass area of the roll groove based on the acquired roll groove profile.
[0016] In an aspect, the method comprises marking a straight line on top of the acquired roll groove profile so as to create an enclosed area of the groove profile. The area is shaded for precise measurement of the area of the roll groove by the processing resource.
[0017] In another aspect, after completion of each milling roll cycle measuring, a mill out area of the roll groove based on the acquired roll groove profile is measured by the processing resource and is compared with the fresh pass area by the processing resource so as to estimate the wear in roll pass.
[0018] In another aspect, the method is implemented using robotic arms coupled to a computing device embedded with audio and video devices.
[0019] In order to further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative only but not used to limit scope of the present subject matter.
[0020] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0021] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally effective embodiments. The detailed description is described with reference to the accompanying figures. The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and methods that are consistent with the subject matter as claimed herein, wherein:
[0022] FIG. 1 illustrates a method of measuring an area of a roll groove of a roll pass of a bar rolling mill in accordance with the present invention disclosure;
[0023] FIGS. 2A-2M illustrate the detailed steps of the method in accordance with the present invention disclosure;
[0024] FIGS. 3A-3E illustrate a comparison between a fresh pass area and a mill out area measured with the method of the present invention disclosure; and
[0025] FIG. 4 and FIG.5 illustrate the graphs between tonnage rolled vs wear in rolled pass area for exemplary stands 2 and 6, respectively.
[0026] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.

DETAILED DESCRIPTION
[0027] The detailed description of various exemplary embodiments of the disclosure is described herein with reference to the accompanying drawings. It should be noted that the embodiments are described herein in such details as to clearly communicate the disclosure. However, the amount of details provided herein is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0028] It is also to be understood that various arrangements may be devised that, although not explicitly described or shown herein, embody the principles of the present disclosure. Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples, are intended to encompass equivalents thereof.
[0029] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “includes” and/or “including,” when used herein, specify the presence of stated features, integers, steps, operations, elements and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and/or groups thereof.
[0030] It should also be noted that in some alternative implementations, the functions/acts noted may occur out of the order noted in the figures. For example, two figures shown in succession may, in fact, be executed concurrently or may sometimes be executed in the reverse order, depending upon the functionality/acts involved.
[0031] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which example embodiments belong. It will be further understood that terms, e.g., those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
[0032] Detection of damages or defects on the roll pass is required in order to mitigate or overcome the consequences of the damages such as poor quality of the workpiece, an increase in machining cost, and decrease in productivity. There are several methods available to measure the wear of the roll groove of a bar milling roll. One such method involves the use of laser technology. In this method, a laser beam profiler captures the image of the profile of the groove of a fresh roll pass and the used roll pass and generates the profile on a liquid crystal display (LCD) screen or a computer using a software. By calculating the area of the generated profile of the roll groove before its operation or when it is unused and after the operation of the roll pass or when it has been brought under operation, the amount of wear can be estimated or compared and then suitable corrective measures can be taken in order to carry the operation of rolling smooth and produce good quality workpiece. However, such a method using laser beam profiler is very expensive.
[0033] Another known method is available where a soft metal such as aluminium is used for offline rolling and taking the impression of the cross-section of the roll groove when it is not used or is freshly manufactured and when it has been brought under application so that amount of wear can be estimated by comparing the area of the cross-section made on the aluminium metal. But this method is tiresome and lengthy. Further, the chances of occurrence of an error are high in this method.
[0034] Yet another known method exists to estimate the wear in the roll groove. The method involves taking the impression of the worn roll groove by using plaster of Paris (PoP), putty or LC wire individually. However, the problem with each of the material used in the method is that PoP gets brittle after drying, putty takes a long time to set and is thicker and with LC wire chances of spring back action prevails.
[0035] Therefore, there is a need to introduce a method which is cheap, less time consuming and provide accurate or precise results.
[0036] FIG. 1 shows an exemplary method 100 of measuring an area of a roll groove of a roll pass of a bar rolling mill in accordance with the present disclosure. The order in which the method 100 is described is not intended to be construed as a limitation, and any number of the described method blocks may be combined in any order to implement the method 100, or an alternative method. Furthermore, method 100 may be implemented by processing resource or computing device(s) through any suitable hardware, non-transitory machine-readable medium/instructions, or combination thereof. In an example, the method may be implemented using robotic arms. The robotic arms may be coupled to a computing device embedded with audio and video devices to monitor and ensure the precise implementation of the method 100.
[0037] As shown in the FIG. 1, the method 100 comprises four broad steps, each step represented by a block of the method 100. The method 100 initiates by marking a straight line across an outer rolling edge of the roll pass. The straight line marked is parallel to the axis of the roll pass and covers the roll groove of the roll pass as represented by block 102. The method 100 follows by applying an measuring medium over the marked straight line on the roll pass. The measuring medium is allowed to set and get harden for a predefined time, represented by block 104. Then the hardened measuring medium is removed from the roll pass and the impression of a roll groove profile acquired by the measuring medium is traced on a recording medium which is disclosed by the block 106. Finally, the method 100 ends by measuring a fresh pass area of the roll groove based on the acquired roll groove profile as represented by block 108. In an aspect, FIG. 1 represents the method 100 in a broader aspect. The method 100 is described in detail with reference to FIGS. 2A-2M.
[0038] FIGS. 2A-2M represent the detailed steps of the above-disclosed method 100. In an aspect, the method 100 can be performed semi-automatic or fully automatic using a number of devices.
[0039] FIG. 2A illustrates marking a straight line across an outer rolling edge of the roll pass 202. The straight line can be drawn by any one instrument such as with the help of a marker, highlighter, pencil, pen, sketch pen, chalk, paint, crayon and the like. The straight line is drawn parallel to the axis of the roll pass 202 and covers the roll groove 202a of the roll pass 202 as shown in the FIG. 2A. Although the marking of a straight line is performed by a human as per FIG. 2A, those skilled in the art can appreciate that this process can be performed by robotic arms under the control of computer device implementing appropriate computer applications.
[0040] After marking the straight line on the roll pass 202, a lubricant or oil is applied on the marked straight line as shown in FIG. 2B for facilitating a measuring medium 204 to adhere or get set on the roll pass.
[0041] In an embodiment, the measuring medium 204 can be an epoxy agent which hardens after the predefined time. The epoxy agent, preferably a multi-purpose sealant, is mixed properly as shown in the FIG. 2C and is given an elongated shape by rolling it manually so as to match the length of the epoxy agent with the marked straight line on the roll pass as shown in the FIG.2D.
[0042] In another embodiment, the measuring medium 204 is a processed wet cotton cloth piece or a thread piece. The processed wet cotton cloth piece is obtained by dipping a cotton cloth piece in a starch solution for a specified time period of, say, 1 minute; removing the cotton cloth piece from the starch solution; and sprinkling acetone on the cotton cloth piece. Then, the processed wet cotton cloth piece is given an elongated shape by stretching it manually so as to match the length of the processed wet cotton cloth piece with the marked straight line on the roll pass.
[0043] After giving the measuring medium 204 the elongated shape of desired length, it is then placed on the marked straight line and pressed to the roll pass 202 so that it gets adhere to the roll pass 202 and any gap between the roll pass surface and the measuring medium 204 is eliminated as shown in the FIG.2E and FIG. 2F, respectively. The measuring medium 204 is allowed to get hardened by leaving it undisturbed for a predefined time so that it acquires the impression of the roll groove profile of the roll pass 202 as shown in FIG. 2G. In an aspect, the predefined time can be 4-6 hours for the measuring medium 204 being the epoxy agent. In another aspect, the predefined time ranges from 5-10 minutes for the measuring medium 204 being the processed wet cotton cloth piece. Also, for the measuring medium 204 being the processed wet cotton cloth piece, the processed wet cotton cloth piece may be hardedned by using an air drier to reduce the time of hardening of the processed wet cotton cloth piece.
[0044] Then, the measuring medium 204 is then carefully removed from the roll groove profile as shown in FIG. 2H. At this stage, the measuring medium 204 has acquired the profile of the roll groove 202a. The measuring medium 204 having the roll groove profile is cleaned to remove the lubricant from it, and is tagged with a tag 206 having relevant details like date, pass number, stand number, etc., for identification and data logging purpose. The measuring medium 204 is then kept on a recording medium 208 as shown in FIG. 2I. In an aspect, the recording medium 208 can be a blank paper. The recording medium 208 is not limited to only blank paper but can be any type of paper such as bond paper, book paper, blotting paper, printing paper, handmade paper, drawing paper, tracing paper, craft paper and the like. Then, with the help of a marker the profile of the measuring medium 204 is traced on the blank paper 208 as shown in FIG. 2J. For tracing the profile of the hardened measuring medium 204, options other than a marker can be used as well. The options can include, but are not limited to, a pen, pencil, sketch pen, paint, crayon, highlighter and the like. The profile is closed by drawing a straight line of length at the top of the traced profile to define the area of the profile, as shown in the FIG. 2K. The length of the straight line to be drawn varies depending on the type of profile acquired by the hardened measuring medium 204. The area of the profile is shaded preferably by an ink, pen, pencil, crayon, paint, highlighter and the like as shown in the FIG. 2L. In an aspect, the colour of the shading is preferably black; however, other dark colours can also be used. The final step of the method is measuring the area of the shaded portion of the profile of the measuring medium 204 by using a processing resource, as shown in the FIG. 2M.
[0045] In an aspect, the processing resource can be a combination of hardware and programming (for example, programmable instructions) to implement one or more functionalities. In examples described herein, such combinations of hardware and programming may be implemented in several different ways. For example, the programming for the processing resource may be processor executable instructions stored on a non-transitory machine-readable storage medium to execute such instructions. In the present examples, the machine-readable storage medium may store instructions that, when executed by the processing resource, implement the processing resources. In other examples, the processing resource may be implemented by electronic circuitry. In other examples, the processing resource may be a pixel calcualting software.
[0046] The processing resource will be able to measure the area precisely as compared to manual calculation. The method is used to measure and compare both a mill out area and a fresh pass area of the roll pass in order to estimate the extent of wear. In an aspect, the method is implemented by robotic arms. The robotic arms are coupled to a computing device embedded with audio and video devices to monitor the method precisely.
[0047] FIG. 3A-3E shows the comparison of areas of a mill out roll pass 304 and a fresh roll pass 302. FIG. 3A shows the way in which the impression of the roll groove of both the fresh roll pass 302 and the same roll pass after frequent usage is being taken by using a measuring medium which is preferably a multipurpose sealant. It is very well visible from the FIG. 3A that the shape or profile of the roll groove of the roll pass (302, 304) after usage has changed because of wear. After taking the impression of the profiles of the hardened measuring medium, the profiles are traced using a recording medium preferably a blank paper and area of both the groove roll are generated as shown in FIG. 3B. The area of both the roll groove profiles of the fresh roll pass and the used roll pass are calculated or measured using processing resource, preferably a computer aided program or software as shown in FIG. 3C. The area measurement performed by the processing resource is more accurate than the conventional manual graph method as shown in FIG. 3D.
[0048] The processing resource measures the dimensions of the groove profile such as depth 306, 306a, collar taper angle 308, width 310, 310a, collar radius 312, 312a of the profiles precisely and provides this data. FIG. 3E shows an example of the values of the groove profiles of the fresh roll pass 302 and used/mill out roll pass 304. It is clearly visible from the exemplary figure that the dimensions of the groove profiles of the fresh roll pass 302 and the used or mill out roll pass 304 have changed or altered due to wear and abrasion due to which the mill out area of the mill out roll pass 304 has reduced as compared to the fresh pass area of the fresh roll pass 302.
[0049] FIG. 4 and FIG. 5 show the graphs between tonnage rolled vs wear in roll passes for stand 2 (having fresh roll 302) and stand 6 (having mill out roll pass 304), respectively. The graphs are made on the basis of the data of Table 1 provided below. Table 1 represents the collection of data of tonnage rolled and wear in roll pass area in a live environment of a bar rolling mill. Table 1 calculates the increase in pass area in mm2 for two roll pass mounted on two stands 2 and 6 respectively. The fresh pass area and mill out pass area in mm2 in the Table 1 is calculated with the help of the method of the present disclosure. With the help of the graphs, it can be observed that with the increase in tonnage rolled, the wear in roll pass also increases. Also, there is another observation which is that wear in respective bottom roll pass is less than the top roll pass. Also, with increase in the tonnage rolled, the gap between the top and bottom roll pass wear also increases.
Table 1: Data of tonnage rolled and wear in roll pass area

Stand No. Out on Initial Dia (mm) Dressing Dia (mm) Roll ID Top/Bottom Pass No. Tonnage Rolled (Ton) Fresh Pass area (mm2) Mill Out Pass area (mm2) Increase in Pass area (mm2)

#2

585

531
KD153391-11
Top 1 30076 5698 6060 362
2 31626 5698 6106 408
3 35572 5698 7042 1344

KD153391-12
Bottom 1 30076 5698 5859 161
2 31626 5698 5868 170
3 35572 5698 6470 772

#6

7th Dec 2018

505

492

N7815

Top 1 27686 1491 1891 400
2 34362 1491 2017 526
3 28111 1491 1930 439
4 33860 1491 2000 509
5 28665 1491 1969 478

N7816

Bottom 1 27686 1491 1861 370
2 34362 1491 1959 468
3 28111 1491 1942 451
4 33860 1491 1957 466
5 28665 1491 1944 453

TECHNICAL ADVANTAGES
[0050] The present disclosure provides a method of measuring an area of a roll groove of a roll pass of a bar rolling mill which is less time-consuming.
[0051] The present disclosure provides a method of measuring an area of a roll groove which provides accurate or precise results.
[0052] The present disclosure provides a method of measuring an area of a roll groove which is simple and cheap or economical.
[0053] The present disclosue provides a method of measuring of a roll groove of a roll pass through an epoxy agent as well as treated cotton cloth piece. On one side, the measurement with epoxy agent takes about 4-6 hours; while, on other side, the measurement with treated cotton cloth piece takes about 15-30 minutes.
[0054] While the foregoing describes various embodiments of the present disclosure, other and further embodiments of the present disclosure may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The present disclosure is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the present disclosure when combined with information and knowledge available to the person having ordinary skill in the art