Applications of Infra-Red Technology at Point Henry

ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry

Alcoa Australia Rolled Products

Applications of Infra-red Technology

at Point Henry Works

Part 1

Written By

Frank Conte Hotline Electrical Process Engineer

20 July 2006

F.A Conte July 20 2006 1 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry

TABLE OF CONTENTS

1: HOT CONTINUOUS MILL SHEET TRACKING ...... 3 2: HRM SLAB HOOKING MEASUREMENT ...... 3 3: HOT CONTINUOUS MILL ENTRY AND EXIT TEMPERATURE MEASUREMENT ...... 3

3.1 HCM Entry Temperature ...... 3

3.2 HCM Exit Temperature ...... 4 4: HRM INGOT AND SLAB TEMPERATURE MEASUREMENT ...... 4 5: HOTLINE HOT METAL DETECTORS ...... 5 APPENDIX 1: ADDITIONAL INFORMATION ON HCM SHEET TRACKING ...... 6

A1.1 Constant Manipulator Pressure Control ...... 7

A1.2 Process Improvement -Constant Manipulator Pressure Control ...... 8 APPENDIX 2: ADDITIONAL INFORMATION ON HRM HOOK CAMERA ...... 10 APPENDIX 3: ADDITIONAL INFORMATION ON HCM ENTRY SLAB TEMPERATURE MEASUREMENT ...... 11

A3.1 Process Analysis using Entry Temperature IRCON

F.A Conte July 20 2006 2 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry ...... 13 APPENDIX 4: ADDITIONAL INFORMATION ON HCM EXIT SHEET TEMPERATURE MEASUREMENT...... 15

A4.1 History ...... 15

A4.2 3T Main Screen Image from 3T software ...... 16

A4.3 3T Maintenance Screen Image from 3T software ...... 16

A4. 4 Calibration of 3T ...... 17

A4.5 How we use the pyrometer on our Hotline ...... 20

A4.6 Summary ...... 21

A4.7 Citect Graph of Entry, Exit (3T) and Exit (Land AST) ...... 21

A4.8 Long Term analysis of data ...... 22 APPENDIX 5: ADDITIONAL INFORMATION ON HRM PYROMETER ...... 24

A5.1 Calibration Results for HRM Pyrometer ...... 25 APPENDIX 6: ADDITIONAL INFORMATION ON HRM HMD’S ...... 26

F.A Conte July 20 2006 3 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry Applications of Infra-red Technology at Point Henry 1: Hot Continuous Mill Sheet Tracking

We have installed an ASC IS3000 (American Sensors Corporation), Scanning Infra-Red sheet edge monitoring device, in the inter-stand area of our 2 stand Hot Continuous Mill (HCM). This device was sourced and installed to measure the operator’s side position of our hot strip, for monitoring sheet tracking.

Hot rolled slab has inherent cracking of the strip edges. It is necessary to trim out all the edge cracks to prevent breaking of the strip in downstream processing. Residual edge cracks (REC’s), act as stress concentrators and source strip breaks when the strip is under tension. Sheet breaks downstream of our hot rolling process, cost the business in the order of $1.8M over approximately 16 months in 2000. REC’s from the hotline contributed to 30% of these breaks. Reduction of sheet breaks through reducing REC’s at the exit of the Hotline was essential, so since 2000, coils found containing mid coil residual edge cracks are now scrapped at the HCM. Scrapping defect coils earlier in the process at the Hotline is more cost effective, however still contributes to major business losses. Solutions were required at the hotline to eliminate or reduce coils with REC’s. Stable tracking of the strip through the mill and subsequent trimmer process is critical to ensure even edge trimming and successfully removing edge cracks.

We had suspected poor sheet tracking issues as one of the causes of REC’s but had no way of monitoring or recording it with any accuracy or automation. The IS3000 provides measurement of the position of the operators side edge with an accuracy of +/-1mm. The environment in which it operates is very harsh. Using this device, we were able to monitor and determine the extent to which our sheet was laterally moving throughout the rolling process and then investigate causes. It was found that entry sheet manipulation significantly affected the tracking of the sheet through the mill, and therefore through the trimmers, and contributed to mid coil REC’s. Using this device, we were able to quickly identify a significant issue with our manipulators and a major limitation in the existing manual control which contributed to REC’s. Repairs and control modifications and enhancements has significantly reduced whole coil scrap due to REC’s and also reduced future damage to our manipulators; as explained further in Appendix 1.

2: HRM Slab Hooking measurement

Based on the success of the HCM interstand infra-red system, we purchased an additional IS3000 infra red scanner and we decided to use it as an “installed spare” for the HCM system. We installed it at the exit of the HRM for measurement of HRM slab hook. This device calculates the slab centreline and reports this to the data collection system. We have not yet fully utilised the output from this device. Our intention is to use this data to monitor progress on future attempts to reduce slab hooking at the HRM. See Appendix 2 for further information.

3: Hot Continuous Mill Entry and Exit Temperature measurement

3.1 HCM Entry Temperature

We have the A.T.C. (Alcoa Technical Centre) developed IRCON Mirage based pyrometer system installed at the entry to our Hot Continuous mill for incoming slab temperature measurement. This device measures the temperature of the under-side of the slab, thus preventing extraneous light interference. It is installed for easy and convenient maintenance access also. The system comprises significantly more complex componentry than other commercially available pyrometers, and also requires ATC proprietary hardware and software. The calibration procedure requires ATC collaboration. The system has been installed on our line since October 2003 and the performance of the device over this time has been stable and repeatable. Calibration testing of the system indicated the necessity to create multiple recipes for our various alloy groups to achieve accurate measurement of our alloy range.

The entry slab temperature is input into our control system for display and manual control at Hot Reversing Mill and for display only at the Hot continuous Mill. The data is also recorded in our data collection system, where we record the Minimum and Maximum temperatures, and their respective positions, of our slab at the nose, body and

F.A Conte July 20 2006 4 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry tail. The continuous data is available on our Citect HMI. We intend to input this temperature into our HCM preset model for more accurate mill modelling and presetting. Previous slab temperature measurement was a manual system implemented by operator using a surface thermocouple probe. The operator results were unreliable due to lack of compliance and “fudged” numbers and due to poor operating practices which produced large errors. In addition, the accuracy of the surface probes was in constant question due to poor supply and treatment. Installation of the ATC system has provided reliable and 100% automated temperature measurement. It has also expanded our understanding of the slab temperature profile which has allowed us to do further process optimisation and monitoring and allowed us to reduce manning levels. For additional Information see Appendix 3

3.2 HCM Exit Temperature

At the exit of our Continuous Mill, we have purchased and installed an ASC (3T) PM3000 Pyrometer for the continuous measurement of exit sheet temperature. This device was chosen after having successfully trialled the device on site in late 2004. The installation and calibration process was simple. Since the start of March 2006, the temperature output of this pyrometer has been used as our official Process Temperature Measurement device. The device, however, has been installed and operating since early 2005. In this time, the output of the device has been very stable, reliable and the calibration has been checked twice by the manufacturer and found to be accurate. The pyrometer achieves a ΔT no more than +/- 5º C.

The continuous temperature data information has been pivotal to the success of other process improvements as will be described in detail in Appendix 4. Currently, the continuous data is used to automatically model the coil temperature which was previously taken manually as a single point sidewall temperature to determine self anneal conditions. The previous measurement of coil temperature was by operator using a surface thermocouple probe. In the same way as the manual entry temperature issues, operator results were unreliable due to lack of compliance and “fudged” numbers and poor operating practices which produced large errors. Not only was the accuracy of the surface probes in constant question due to poor probe supply and treatment but there was an inherent issue with the adequacy of surface probes measuring the rough sidewall conditions of our coils. Installation of this automated measure has also eliminated a safety risk (exposure to hot coil and crane interaction) from the process. For further information see Appendix 4

After commissioning of the pyrometer as our process measure, we saw a reduction in the amount of coils going to furnace for anneal. However, after having used the pyrometer data to discover a very important process relationship between Earing (a critical quality parameter for Rolled Can Sheet. (RCS)) and stand 2 Slip (differential speed between roll surface and strip), we implemented an Earing control strategy. This strategy caused an increase in coils requiring Furnace Anneal but protected us from coil losses resulting from high Earing properties. The deeper understanding we now have of our thermo-mechanical process means that we no longer do this. This automation has not only provided a reliable and stable exit temperature reading but also allowed the Hotline to reduce manning. The appendix also covers our attempts to verify the online “running” calibration of this system. The accuracy of this system is well within the minimum specification of +/- 10 oC. The system has the ability to store 40 different spectral calibrations (groups), however given our narrow alloy range, we were able to obtain satisfactory performance with only one group.

The 3T pyrometer is supplied and supported via ASC (American Sensors Corporation), who are based in Pennsylvania in the USA. The cooperation between 3T, ASC and Point Henry has been critical to the success of this and other projects where ASC products were used.

4: HRM Ingot and slab temperature measurement

We have purchased and installed an ASC (3T) PM 3000 Pyrometer for measurement of incoming ingot temperature for the Hot Reversing Mill. The device also measures strip temperatures for 4th last and 2 nd last rolling passes. The pyrometer is installed above the line and provided with mechanical shielding of extraneous light; therefore the installation of this device was more involved than the HCM exit system. Commissioning and set

F.A Conte July 20 2006 5 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry up of the PM3000, however was a simple process. Calibration during commissioning of the pyrometer proved that, in order to achieve required accuracy, we required different Calibration “groups” for Ingot verses rolled slab due to the very different spectral properties of each. The PLC switches calibration groups within the PM 3000 automatically. Calibration of each group is a simple task requiring a surface style ANRITSU thermocouple and PC connection to the pyrometer. We were able to achieve accuracy of +/- 3oC , refer to Appendix 5

Currently the ingot temperature measurement requires the ingot to be positioned under a “boom gate” styled device which lowers 3 surface probes onto the ingot to take measurement. This process requires approx 30 seconds per ingot, and therefore potentially costs us one slab lost per shift. This represents 2% of our rolling production! The new pyrometer can snapshot the ingot temperature while it is driven to the mill from the preheats. In addition, the pyrometer is able to read 4th and 2nd last pass slab temperatures. In future, these temperatures will be input into the mill control system to control the final pass speed of the mill to target HRM exit temperature.

5: Hotline Hot Metal Detectors

Point Henry currently use IRCON Hot metal Detectors (HMD), circa 1980’s, for automation of our Hot Mill. The IRCON has been a very reliable and successful device, but is ageing and now showing signs of deterioration, in the form of poor reliability. One of the pitfalls of the IRCON HMD is the adjustment of sensitivity and triggering. Because of the “infra-red” difficulty of some of our applications, we require accurate setting of the switching threshold for reliable operation. We are, however, unable to determine how close we are to threshold or what level background energy we have. We have now purchased the ASC HMD 3000 as a replacement device, after successful testing on site. These devices have Automatic Gain Control, which assist us with marginal signal applications. They also display recorded energy level in the same units as the switching threshold value. Therefore we are able to determine and monitor received (target emitted) and background energy, and easily and reliably adjust the switching threshold. Another feature of the device is the laser pointer and the wireless operation ability. Process sequencing difficulties created by troublesome HMD’s cost us significant dollars from scrap slabs and lost production time from diagnosis and remediation of scrap. This is in the order of $50K per year. A significant benefit of this purchase is the dedication and support provided by ASC for customising and development of solutions.

See Appendix 6 for further information.

F.A Conte July 20 2006 6 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry Appendix 1: Additional information on HCM sheet tracking

The inter-stand scanner helped identify the variation in incoming sheet width we previously did not have a good understanding for. We found our slab width is up to 40mm wider on the nose compared to the body. The tail is also wider than the body, but generally not to the same degree. In some cases, however, due to ingot butt swell, the tail can be significantly wider.

TAIL NOSE +40MM

Under our previous manual manipulation operation, the operator would close the manipulators on the nose of the incoming slab and then feed it into the mill. Unless the operator regularly closes the manipulators on the body of the slab, the sheet was able to move or slide to one side within the manipulators, as its width narrowed. A movement of only 20mm was sufficient to cause enough movement of the strip across the roll bite to be a problem in the trimmers. Given that we may trim as little as 40mm off each side of strip, and the average normal edge crack may be up to 20mm deep we have little to play with. A movement of 20mm in sheet tracking can be sufficient to cause untrimmed edge crack. Manipulators not closed on Manipulators closed on sheet body allowing slab to sheet nose before move threading

Sheet Direction

Manipulators closed on body of sheet now being forced apart by wider tail In addition, if the operator did close the manipulators tight on the body of the slab (narrowest part), then as the wider tail entered the “hydraulically locked” manipulators, the tail would wedge open the manipulators causing great pressure in the hydraulic system. This effect was measured to double normal running pressures during such scenarios causing subsequent damage to manipulator rollers and hydraulics which led to further sheet movement and bad tracking and therefore more edge cracks. The pictures below show the entry manipulators. On the left hand side the coil has recently started and the manipulators are “tight”. On the right, the slab is halfway through and, although it is difficult to notice in the photographs, the gap between the right hand side manipulator and the sheet has opened allowing the sheet to angle into stand 1 roll bite. Start of coil. Manips closed tight Mid Coil Manips loose

F.A Conte July 20 2006 7 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry The following, shows a calibration result of the IS3000 , as installed in the mill

Calibration Testing of the IS3000 tested insitu 2 t

n 1.5 e m

r 1 u s

a 0.5 e m 0 n i

0 0 0 0 0 0 0 0 0 0 0 0 r 0 5 0 5 0 5 5 0 5 5 0 o -0.5 - r 3 2 2 1 1 1 1 2 2 r - - - - E -1 m

m -1.5 -2 Distance from IS3000 centreline

A1.1 Constant Manipulator Pressure Control As a result of our studies using the output of the IS3000, we installed manipulator laser position measurement and pressure control and implemented a constant pressure control strategy. This means that during the running of the slab we maintain a set constant pressure on the slab to maintain optimum sheet tracking.

The graphs below (from our Citect system) show manipulator extension (0mm from full open position in Blue), Operator’s side edge position in the interstand area (IS3000 in Red) and manipulator activation in Green. The first graph (left) shows the performance of a coil run with the normal manual manipulator control. The second graph (on the right) shows the performance of a coil run with constant pressure control. The tracking improvement is obvious.

Normal Constant Pressure

F.A Conte July 20 2006 8 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry Comparison of Normal manipulator control and Constant Pressure control

Constant Pressure

A1.2 Process Improvement -Constant Manipulator Pressure Control The graph below shows the significant improvement after Manipulator Work

Coils scrapped due to Residual Edge Cracks 2005

25 MANIP KAISEN WORK s l i

o 20 C

d e p p a r 15 c S

0 JAN FEB MAR APR MAY JUN JULY AUG Month

Installation of the IS 3000 Scanner in the Hot Continuous Mill Inter-stand area F.A Conte July 20 2006 9 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry

We added a protective splash cover and air curtain

F.A Conte July 20 2006 10 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry Appendix 2: Additional information on HRM hook Camera Installation of the IS 3000 Scanner on crossover at exit of HRM

Picture of Exit of HRM showing a slab with significant drive side hook

F.A Conte July 20 2006 11 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry Appendix 3: Additional information on HCM Entry Slab temperature Measurement

GA of ATC (Ircon Mirage) Pyrometer System Installed at Pyrometer undersheet viewing port PTH

ATC (Ircon Mirage) Pyrometer slide frame for retracting pyrometer

Ircon Mirage Processor and ATC PIPLOG device for calibration

F.A Conte July 20 2006 12 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry ATC Pyrometer system overview

Modcomp PIP Ircon Ircon Computer Mirage Head Process or

Calibration Results using Single Recipe Alloy Average Error Average Error Test 1 Test 2 5042 -8 -6 3004 0 -2 PH520 -17 -11 PH321 -31 -14 PH519 -28 -17

These results indicated the necessity of the creation of an additional 3 alloy recipes to obtain minimum performance of ATC Pyrometer Interface Processor (PIP) +/-10oC

Examples : Summary profiles using snapshot data to nose, body and tail for each card

DNI Transfer Slab Temperature Profiles 500 series Transfer Slab Temperature Profiles

440 440

420 420 544 266 556 400 278 400 563 289 567 380 353 380 584 354 360 360 590

340 340 0 20 40 60 80 100 0 10 20 30 40 50 60 70 80 90 100 110 120 130

600 series Transfer Slab Temperature Profiles

420 610 400 612 380 625 649 360

340 0 10 20 30 40 50 60 70 80 90 100 110 120 130

F.A Conte July 20 2006 13 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry Examples : Citect Screen showing continuous temperature trends. Green line = Entry Slab Temperature, Red = Exit temperature (ASC/3T device)

A3.1 Process Analysis using Entry Temperature IRCON To reduce tails going under our bottom stripper at the HRM, we implemented an additional bubble pass on our Z tooling endsheet product. We used the entry IRCON to establish the effect on Tail temperatures as seen at the HCM. As can be clearly illustrated in the data., there is a significant process shift

450 445 440 435 430 425 420 415 410 405 400 395 390 385 380 375 370 365 360 355 350 345 340 335 330 325 320 315 310 305 300 6 6 6 6 6 6 6 6 6 6 d 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 e 0 0 0 0 0 0 0 0 0 0 0 0 0 0 l ------l r r r r r r r r r r r n n n n n n n n n n n n n n b b b b b b b b b b b b b b b o a a a a a a a a a a a a a a a a a a a a e e e a a a a a e e e e e e e e e e e e R J J J J J J J J J J J J J J

F F F M M M M F F F F F F F F F F F F M M M M M M M ------e t 8 9 9 4 6 6 8 9 0 3 8 0 3 1 3 4 5 7 9 5 7 8 7 1 3 4 6 6 8 0 1 0 2 5 9 0 5 5 6 9 a 1 1 1 1 1 2 2 2 3 1 1 1 1 1 1 1 2 2 2 1 1 1 1 2 D

tail_min_temp tail_max_temp 20 per. Mov. Avg. (tail_max_temp) 20 per. Mov. Avg. (tail_min_temp)

Z TOOLING TAIL Minimum and Maximum temperatures from Jan 1- 20th vs Jan 21st - YTD

390 382 oC 378 oC 380

370 e r u t a r

e 360 p

m 353 oC e T 350

340 -28oC

330 325 oC

320 tail_min_temp tail_max_temp

Average Before RBUBBLE Average After RBUBBLE

F.A Conte July 20 2006 15 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry Appendix 4: Additional information on HCM Exit Sheet Temperature Measurement.

A4.1 History After having worked on the continuous mill inter-stand sheet tracking project with American Sensors Corporation (ASC), they became aware of our mill requirements and offered us the opportunity to prove their Pyrometer for exit temperature application. ASC have had success at other Aluminium processing plants around the world and were committed to proving their equipment on our process. ASC organised the delivery of the 3T pyrometer and organised an Engineer from 3T to assist with any system questions and the setup in Oct 2004. We installed the pyrometer in a temporary location for the trial, viewing the outside wrap of the coil on the rewind mandrel approximately in the centre of the sheet. See Photographs

Initial test location for 3T Pyrometer Laser Alignment spot from 3T Pyrometer on coil wall

Within minutes of connecting up the notebook computer and taking ANRITSU thermocouple calibrations (stationary on the tail), the 3T pyrometer was providing accurate runtime continuous temperature measurements of the coil throughout the rolling process. The results were repeatable within 5 oC and accuracy of +/-10oC with the thermocouple measurement. It must be mentioned here that repeatability of the test measurement with the thermocouple (surface type) was somewhat questionable as it requires significant care to ensure correct orientation. Any angle deviation creates significant (in the order of 40oC) error. We purchased the device in 2005.

Testing was conducted to assess the effect of extraneous light on the output of the 3T device in this location. With the exception of the exit flood light which is used for viewing exit scrap after tail out, no other normal sources of lighting appeared to have any effect on the pyrometer output. The 3T device has been left in service ever since this initial trial.

A4.2 3T Main Screen Image from 3T software The following screen is the monitoring screen

A4.3 3T Maintenance Screen Image from 3T software Simple adjustment of Dx and Dy factors allows fine tuning of the device for calibration

F.A Conte July 20 2006 17 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry In Jan 2006, 3T and ASC came to PTH again to review the performance of the pyrometer on the HCM in readiness for a comparative trial with LAND AST pyrometer and the LAND infra-red scanner. The calibration setups from the initial setup were still valid in Jan 06. The LAND AST (single point pyrometer) was installed in the same location as the 3T, viewing the same point on the coil. The Land AST is specifically designed for aluminium applications. In April LAND engineers came to site to setup their device.

Photo showing our single point Pyrometers and operators taking the coil temperature

“Image removed( is 6Mb) – too big for email” “Image removed( is 6Mb) – too big for email”

Land AST pyrometer installed above the 3T (now in a protective cover) A4. 4 Calibration of 3T My biggest initial concern with the pyrometer readings was ensuring the calibration was relevant throughout the coil. I was concerned that perhaps the spectral qualities of the hot rolled sheet was somehow different throughout the rolling process and therefore we may have calibration errors. It is physically not possible to test the temperature of the sheet surface as it moves, so we had to look elsewhere for an answer. LAND have a 2 dimensional infra red scanner which is capable of measuring the temperature of a “field of view”. The infra red sensors used in this device are not suited to aluminium with its low emissivity, however LAND have worked out an approach which they believe allows accurate absolute temperature measurement for coiling aluminium. They believe that the inward NIP formed between the coil on the mandrel and the sheet being rolled up from the mill forms a pseudo "Black Body" situation. Therefore measurement of the temperature seen in the depths of this NIP will produce accurate information.

Apparently a number of technical people around the world have acknowledged this theory and have installed single point pyrometers with scanning actuators to follow the nip. The difficulty here is to ensure the pyrometer is accurately pointing into and measuring the deepest part of the nip. The LAND system has the advantage of being able to see the entire movement of the NIP from first wraps to final wraps from one position, if positioned correctly. In addition, the LAND software allows the user to detect and track the maximum temperature seen in the field of view , which will inherently always be the deepest part of the nip. LAND claim that this device does not need process calibration because the emissivity is considered 1.0 in the maximum temperature spot so the factory black body calibration is sufficient for providing an absolute temperature. Having this explained to me gave me some confidence that I may have an opportunity to not only allow LAND the opportunity to promote their equipment, which they were happy to do, but to provide an additional confirmation of the data from the AST and 3T single point pyrometers.

Land tell us that other Alcoa locations are using this type of approach to cold rolling applications where the temperatures are far too low for conventional pyrometers to work on the surface. LAND application engineers came to Australia in April with their scanner (approx $80K AUD) and ran a number of trials, collecting runtime data in conjunction with the 3T and AST single point pyrometers. I have the results summarised below

Photo of our HCM exit Area showing the LAND scanner positioned for testing

“Image removed( is 6Mb) – too big for email”

Land IR Scanner

Output of LAND Infra-Red Scanner The screen image, opposite, is the output from the LAND scanner. It shows the infra-red image of the coil nip as the coil is being wound. The software, finds the maximum point on the image.

Comparative trials between ASC/3T, LAND AST and LAND Imager,

DNI Alloy

Temperature Comparison 17228

400.00

390.00 Temperature Comparison 16125

380.00400

370.00390

360.00380

350.00370

340.00360 e r u t 330.00350 a r e p 320.00340 m e e r T u 310.00t 330 a r e 300.00p 320 m e T 290.00310

280.00300

270.00290

260.00280

250.00270 2 6 1 5 9 0 4 8 9 3 7 8 2 6 0 7 1 5 9 6 0 7 1 5 9 3 0 7 4 8 2 6 3 7 1 5 2 6 0 4 1 5 9 3 4 8 2 3 4 8 2 2 2 3 4 5 5 0 1 1 2 3 3 4 5 0 0 1 2 2 3 4 4 5 0 1 1 2 3 3 4 5 5 0 1 2 2 3 4 4 5 0 0 1 2 3 3 4 5 5 0 1 : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 8 8 8 8 8 8 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 3 3 3 3 3 3 3 3 3 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : 4 4 4 4 4 4 4 4 4 4 4 4 4 4 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5 5

260 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Time 250 3TTT Land AST Land FTI6

Time 3TTT Land AST Land FTi6

EOE- Endsheet Alloy

The most pleasing summary from the results above is that the shape of the temperature profiles between all three devices was basically the same and the only difference was a simple offset. The question now is, “is the offset the result of calibration process errors or actual device accuracy errors?”.

A4.5 How we use the pyrometer on our Hotline Historically, we took the manually measured temperature of our exit coils using a single thermocouple measurement on the side wall at a given spot for DNI and a different spot for EOE. This was a manual system, performed on every coil. From a number of trials throughout our Self Anneal development days, a set of Minimum temperature limits were agreed upon. Above these limits, the coils were not furnace Annealed and simply placed on the floor. Under natural cooling conditions, these coils achieved full recrystallisation. Below a minimum temperature, these coils were furnace annealed. These limits seemed to work OK, however we still experienced Earing excursions, which were unexplained and believed to be a number of possible upstream influences.

About the same time that we started getting complete temperature profiles from the pyrometer for hot rolled coils, investigations were underway to test the earing properties of a coil throughout its length. A revelation appeared! The earing profile matched almost exactly the temperature profile. Given this I began work to reduce the variation in exit temperature and ran constant exit temperature trials using the pyrometer in closed loop control. We were able to achieve pretty good constant temperature coils however the earring results were not favourable.

HCM Auto Exit Temperature Control Trial Aug 29 Second Attempt - Deadband 1oC 430

420 COIL NORM: EXIT = 333oC 410

380 COIL LAST: RATNIC=0.5, dropped SP to e

r 370 EN-LAST

u 330 to prevent initial overshoot, then SP = t LOT 38217

a EX-LAST

r 340. Dband =1oC EXIT = 315oC e 360 EN-PREV p

m EX-PREV e

T 350 LOT 38218 EN NORM 340 EX NORM LOT 38219 330

310 COIL PREV: RATNIC=2.0, dropped SP to 320 to prevent initial overshoot, then SP = 300 330. Dband =1oC EXIT = 310oC

Through tracking the temperature profiles in Citect, we also noticed a relationship between stand 2 slip and the Earing results obtained. Our Metallurgist then organised extensive testing for Earing for coils with high or normal stand 2 slip and coils that were and were not annealed. The testing was performed on the butts (first 200mm from coil ID) of our coils at our slitter. The Earing results were correlated with actual stand 2 slip recorded by our Citect system. When ran statistical analysis of the data, he found a staggering 70% correlation between stand 2 SLIP and Earing. We soon realised that the perceived relationship between temperature and earring was really the similar relationship between SLIP and temperature. Since this time, we have instituted controls for stand 2 slip and have almost fully controlled our earring issues.

In March this year we began using our Pyrometer as our automated temperature measurement device for final coil temperature. The problem we faced now is that given we have a temperature profile, on what basis do we now decide if the coil has reached self anneal status. We previously had a single measure which we became accustomed to treating as “go” or “no go”, and now we have a full profile which is so much more information than we used to have but how do we now decide if we have reached self anneal. The previous limits on the single measure were developed over time and appeared to provide a good overall indicator. So our metallurgist developed a model based on Peak Pyrometer Temperature and Mid Coil temperature) which returns a single temperature to model the manual sidewall temperature with a correlation indicated below.

Model for DNI alloys – best fit achieved for data from B crew – RSquare = 0.72

Exit T = 71.66 + 0.77 * Peak T – 0.599 * (Peak T – Midcoil T)

Current Estimates SSE DFE MSE RSquare RSquare Adj Cp AIC 1333.9793 56 23.82106 0.7269 0.7590 3 189.9847

Parameter Estimate nDF SS "F Ratio" "Prob>F" Intercept 71.6553099 1 0 0.000 1.0000 PeakT 0.77084964 1 3554.437 149.214 0.0000 Peak - Midcoil -0.5985875 1 341.7659 14.347 0.0004

Model for PH522 alloy – data from B crew – Rsquare = 0.56

Exit T = 247.6 + 0.281 * Peak T – 0.999 * (Peak T – Midcoil T)

Current Estimates SSE DFE MSE RSquare RSquare Adj Cp AIC 1451.7444 60 24.19574 0.5587 0.5440 3 203.6553

Parameter Estimate nDF SS "F Ratio" "Prob>F" Intercept 247.601331 1 0 0.000 1.0000 PeakT 0.2810024 1 319.431 13.202 0.0006 PeakT - Mid T -0.9992705 1 1152.214 47.621 0.0000

So the operator is provided with a single "modelled" coil temperature. We have also provided automated temperature measurement indication of wheather the coil has passed self anneal or requires furnace anneal.

A4.6 Summary

We have now been using this device for 5 months as our process output measure. We have  eliminated several safety risks associated with exit temperature measurement  not had a single Earing failure due to insufficient recrystallization - this could happen if the modelled temp was set too low. Our metallurgist believes the current limit for DNI (315C) is conservative and currently collates data from coils that deliberately did not furnace anneal, even the modelled exit temp was 313-314C. So far about 5 such coils had OK Earing.  We have not had an opportunity to do a more detailed study, however, we believe that we have a better (lower) distribution as the manual error has been eliminated.  We believe we must have reduced a number of coils requiring furnace anneal compared to manual temp measurement. In the past we may have had a number of coils that had temperature measured by the operator with mini-temp too low - due to incorrect technique, faulty device etc, and as such were sent to furnace anneal unnecessarily.  Reduced manning  Have continuous data on through which we can further investigate/analyse the process

A4.7 Citect Graph of Entry, Exit (3T) and Exit (Land AST)

A4.8 Long Term analysis of data Now that we have had the Pyrometer operating for almost 5 months we have analysed the long term data. The graph below indicates that since the 22nd Feb there appears to be a reduction in the variability and the average Finished Earing results. In addition, it can be clearly seen that although there was an initial reduction in furnace anneals, the number of Earring failures has dropped but this is combined with an increased rate of Furnace anneals. Further analysis of other factors is necessary, however it is believed that a significant coolant issue could also be implicated.

DNI Finish Earing

6 1500

5.5 1300

5 1100

4.5 900 % l

a g e n i n r n a A

E 4 700

h m s u i n C i

F 3.5 500

2.5 100

2 -100

Exit T Fin earing Cum Anneal 40 per. Mov. Avg. (Exit T) 100 per. Mov. Avg. (Fin earing)

F.A Conte July 20 2006 23 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry The graph below, shows the exit temperatures against the furnace anneal rates. It quite clearly that we have a significant reduction in variation since running with Modelled exit temperatures. It also appears on the graph that we have a lower average exit temperature since we began to use of the pyrometer. From recent discussions with our metallurgist, he informs me that, 315oC model temperature is equivalent to 320oC manual measure. Therefore, given the data before 22nd Feb 2006 represents previous manual measure and after 22nd Feb represents the Modelled Exit temperature, we would expect a 5oC lowering of reported temperature.

DNI Exit Temperature Trends

360 1500

350 1300 340 1100 330

r 900 s u l t a a r 310 e e n p 700 n a m

300 M T

U t i C x

E 290 500

280 300 270 100 260

250 -100

Exit T Cum Anneal 40 per. Mov. Avg. (Exit T)

Appendix 5: Additional information on HRM Pyrometer

ASC 3T Pyromet er

A5.1 Calibration Results for HRM Pyrometer

Alloy AL5182 Alloy AL3004

Ingot (Gr.5) Strip (Gr.4) Ingot (Gr.3) Strip (Gr.2) Dx = 1.0704; Dx = 1.025 Dx = 1.0704; Dx = 1.025 Dy = -0.0416 Dy = -0.060 Dy = -0.1466 Dy = -0.074 Anritsu Lunar Anritsu Anritsu Lunar Anritsu T/C, 3T, T/C, T/C, 3T, T/C, 3T, T/C, T/C, 3T, ºC ºC ºC ºC ºC ºC ºC ºC ºC ºC

505 503 --- 491 492 524 527 526 464 469

521 523 --- 457 458 519 519 519 469 473

496 496 --- 505 506 519 519 524 469 473

468 469 497 499 498 465 470

465* 465*

450* 452*

* after final tuning

F.A Conte July 20 2006 26 ALCOA AUSTRALIAN ROLLED PRODUCTS Applications of Infra-red Technology at Point Henry Appendix 6: Additional information on HRM HMD’s

NEW IRCON ASC HMD HMD

F.A Conte July 20 2006 27