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1. Tracking Calculation Points 200 0 eeeeesssscceccceceeeesennecececececesssnnnaeceeeeeceeseneaaececeeecessessaaaaeeees 6 Figure 7 Speed Profile and Transfer Times between Mill Stands eeeeeeeerere 7 Figure 8 Force Geometric Factor with Peening Effect nennen 7 Figure 9 Mill Stand Drive showing Motor Power and Torque Calculations eeeeeeees 8 Figure 10 Roll Bite illustrating contact length L bite angle roll force P and tensions S 9 Figure 11 Lever Arm Coefficient m as a Function of Roll Bite Geometry 10 Figure 12 Increased Edger Efficiency with Grooved Edger Rolls eeesssseccccceeeseesennnaececeeeeeeeeneaes 12 Figure 13 Error and Warning Messages ssssseeccececeeeseessneececececessessneaaeceeeeecessensnecaeeeeeeeeeeeeeaas 13 Figure 14 Shape Envelope and Calculated Curve essere 14 Figure 15 Single vs Multiple Node Calculations eese nennen eee eren 15 Figure 16 Resistance to Deformation Geometric Factor eseseeeeseeeeeeeeeeeeneeeen enne 17 Figure 17 Resistance to Deformation Temperature Factor ccccccceceesssseeececececeeeesenneaeceeeeeeeeeeeaas 17 Figure 18 Shida Flow Stress as Function of Carbon Content eese 18 Figure 19 Medina Flow Stress for HSLA 50 c sccccccecesssseseecececececeesennnae
2. Coiling Temperature 11 21 C 1 73 Yield Strength 23 93MPa 749 Tensile Strength 13 27Mpa 3 0396 19 67 Table 4 Statistical Analysis of Comparison between Actual and Calculated TRP 0040 Final Report 34 March 30 2005 4 HSMM User Documentation A complete set of documentation including users and technical manuals were generated during the project and are included in Appendix A 4 1 User s Manual The purpose of this document is to provide an overview of the HSMM a brief background on some of the theories used in the HSMM and a thorough description of the HSsMM User s Interface and its functionality 4 2 Getting Started This document is intended to help the user get quickly oriented with the HSMM understand how to utilize the HSMM to study and improve his her mill operations and to make him her aware of some of the advanced features of the HSMM The sections of this document are e Part I Quick Tour e Part II Working with the HSMM 4 3 Calibration Guide This guide provides the procedures for properly setting up an HSMM Calibration Module to accurately simulate a particular grade These procedures involve using plant data for tuning the temperature and force model coefficients to get the calculated values to closely match the measured ones for both the single and multiple node models 44 Client Database Link Instructions This document contains general information and instructions on how to connect the HSMM inter
3. Speed Time Shape Crown Temperature Data Rolling Parameters Microstructure Run Out Table Charts and Summary Results e The Data Exporting Screen allows the user to export data easily from the model to data files that can be easily read by Microsoft Excel or similar software packages for further analysis e The Reporting Screen is used for printing reports containing Mill Configuration Calibration and Rolling Schedule data e The GradeBuilder Screens allows the user to build his her own grade in addition to the nine sample grades characterized for the HSMM TRP 0040 Final Report 2 March 30 2005 ICE E Mare Calter Company Name 3 ai a Ciutenis DISK Grace DOSK veedorty Thawed iade UEC vendor Caiculaton Mode Tinge Mote Fiol Bite Method Fewmance o Datoeesnon Dae Mode VIO 1 32 04 AM Codi ferit Unna Figure 2 User Interface for HSMM version 6 2 2 1 2 Fortran Code The version 4 0 executable programs were built from eight Fortran source files To make this software more understandable and maintainable several enhancements were made to bring the software up to modern software engineering standards Sub divide the eight Fortran source files into smaller individual modules Eliminate duplication of functionality between the original source files Use longer more descriptive variable names Add program block separators and descriptive comments Add reasonability checking to
4. 23 7 Additional Mill Equipment aco eee orte ehe ede eed pur see seio eed as ese eie iuis Red 14 2 3 Improved Flexibility mercon etes i eie a E a EA EEE EiS 14 234 Added Single Node Calculations eese siente eene ennnee 14 2 3 2 Added Resistance to Deformation Force Model sees 16 2 3 3 Added Other Flow Stress Models e perte teo seas deasazooaney owe eed E dnd eae 18 2 3 4 Added Temperature Tuning Coefficients sssseeeeeeeen 19 2 3 5 Added Automatic Force Model Calibration eene 21 2 3 6 Added Plant Database Importing etie IE en etn o beth eee ena eu eh REL Pena 23 2 3 7 Handle Low Coiling Temperdtutes ooi deese sen eap tenaci gesue e ad ed eerie tne au beads 23 2 4 Improved Microstructure Mechanical Properties Calculations esses 24 2 4 1 Allow Chemistry AGISFRG ori oa iae qo eoa erase due o ee sat ees uode pae tires ean 24 2 4 2 Added GradeBuilder Module ias toto Orr b pt ep qudd Saec ides n eeicte dus 24 2 4 3 Extended ROT Transformation Model into Coiler esses 27 2 4 4 Improved Elongation Calculation eese 27 2 4 5 Improved Vanadium Precipitation Strengthening Calculation 28 2 4 6 Added Models for Dual PhaseSieel seo inte dye eco deaur tun eerie aee pde tide bens 20 3 HSMM Validation sedie REP DU E ANE UAR UI EA n QUE Pede enna
5. DEFORM_RADIUS EXIT_DIM Check if SQRT factor is out of range IF SQRT_PARAM lt 0 THEN Exp function out of range ERROR_CODE DESCRIPTION ERROR_INVALID_CALC ERROR_CODE AREA MOD_SIMS_GEO_FACTOR RETURN END IF ROLL_DEFORM_FORCE SQRT SQRT_PARAM Calculate the frictional force experienced by the roll SQRT_PARAM DECIMAL_REDUCTION 1 0 DECIMAL_REDUCTION Check if SQRT factor is out of range IF SQRT_PARAM lt 0 THEN Exp function out of range ERROR_CODE DESCRIPTION ERROR_INVALID_CALC ERROR_CODE AREA MOD_SIMS_GEO_FACTOR RETURN END IF FRICT_FORCE SQRT SQRT_PARAM Calculate the angle of contact of the strip at a neutral point See equation 2 55 in the steckel mill model theoretical manual CONTACT ANGLE ATAN PI LOG 1 0 DECIMAL REDUCTION amp 8 0 ROLL DEFORM FORCE 0 5 ATAN FRICT_FORCE ROLL DEFORM FORCE Find the thickness at the neutral point THICK NEUT 2 0E0 DEFORM RADIUS 1 0D0 COS CONTACT ANGLB EXIT DIM Calculate Sim s geometrical factor See equation 2 54 in the steckel mill model theoretical manual QP PI 2 0 FRICT FORCE ATAN FRICT FORCE PI 4 0 amp ROLL DEFORM FORCE FRICT FORCE LOG THICK NEUT EXIT DIM amp 0 5 LOG 1 0 DECIMAL REDUCTION Figure 5 Sample Fortran 95 code with error checking comments amp descriptive names After the Fortran code was sub divided into smaller calculation modules flow charts were developed a
6. STTR DATA Release date required no more than 4 c VOLUME years from date listed in Part I E above MM DD YYYY e SERIAL IDENTIFIER e g ISSN or CODEN 7 OFFICE OF NUCLEAR ENERGY APPLICED TECHNOLOGY Recipient Contract Point of Contact Contact for additional information contact or organization name To be included in published citations and who would Receive any external questions about the content of the STI Product or the research contained herein Richard Shulkosky Vice President INTEG process Name and or Position O 4 OTHER SPECIFY G STI Product Reporting Period 11 01 2001 Thru_ 03 30 2005 MM DD YYYY MM DD YYYY INTEG process group inc 11279 Perry Hwy Ste 107 Wexford PA 15090 DO E 2 01 p 2 of 2 UNITED STATES DEPARTMENT OF ENERGY DOE OMB CONTROL NO Announcement of Scientific and Technical Information STI 1910 1400 For Use By Financial Assistance Recipients and Non M amp O M amp l Contractors PART Il STI PRODUCT MEDIA FORMAT and LOCATION TRANSMISSION To be completed by Recipient Contractor A Media Format Information 1 MEDIUM OF STI PRODUCT IS Electronic Document O Computer Medium CJ Audiovisual Material O Paper O No Fulttext 2 SIZE OF STI PRODUCT 48 Pages 721 KB 3 SPECIFY FILE FORMAT OF ELECTRONIC DOCUMENT BEING TRANSMITTED INDICATE O SGML O HTML O XML X PDF Normal O PDF Image O TIFFG4 O WP indicate Version 5 0 or greater Platform operation system O MS
7. Stress Grade Development Procedure doc Microstructure Grade Development Procedure doc Appendix B UBC Report on Dual Phase Mo 600 Steel The UBC report titled Microstructure model for hot strip rolling of DP Mo steel referred to in Section 2 4 6 is provided in the following PDF file e UBC ReportforInteg Nov2004Mechanical Properties doc e UBC ReportforInteg Nov2004microstructure doc Protected Metals Initiative Data This Protected Metals Initiative Data was produced under a Cooperative Agreement identified as DE FC36 971ID13554 under a DOE Metals Initiative Project and may not be published disseminated or disclosed to others until five 5 years from March 30 2005 unless written authorization is obtained from the American Iron and Steel Institute Vice President of Manufacturing and Technology Upon expiration of the period of protection set forth in this legend the Government shall have unlimited rights in this data TRP 0040 Final Report 37 March 30 2005
8. The normalized resistance to deformation Ky is the value of resistance to deformation of the rolled material at the selected normalized temperature and at a normalized aspect ratio which has a value of 1 This method is semi empirical but allows the model to accurately calculate the force predictions by using plant data from previously processed coils for any grade of steel Once the model is calibrated using this method new rolling schedules for the same grade can be accurately simulated for conducting what if analysis The user has the choice of which rolling force model to use either flow stress or resistance to deformation 2 3 3 Added Other Flow Stress Models Both the Shida and Medina flow stress calculation methods were added for using grades of steel not characterized in the lab for the NIST developed equations nor were previously rolled in the user s mill to provide data for the resistance to deformation calibration Like the NIST flow stress method these methods define the flow stress of steels during hot plastic deformation as a function of temperature strain strain rate and austenite grain size However what distinguishes these two flow stress models and makes them useful is that they calculate flow stress also as a function of the steel s chemical composition The Shida flow stress model was developed by S Shida of Hitachi Research in 1974 This model is applicable to C Mn steel grades that may contain a small amount of
9. and validated Jerrid Chapman the model using actual operating data from the steel plants and E mail Address es enhanced the model to improve prediction results rshulkosky integog com K Intellectual Property Distribution Limitations must select at least one if uncertain contact your Contracting Officer CO 1 UNLIMITED ANNOUNCEMENT available to U S and non U S public the Government assumes no liability STI Product Issue Date Date of Publication for disclosure of such data 03 30 2005 COPYRIGHTED MATERIAL Are there any restrictions MM DDYYYY based on copyright L Yes x No If yes list the restrictions as contained in your award document STI Product Type Select only one 1 TECHNICAL REPORT X Final O Other specify PATENTABLE MATERIAL THERE IS PATENTABLE MATERIAL IN THE DOCUMENT INENTION DISCLOSURE SUBMITTED TO DOE DOE Docket Number S Sections are marked as restricted distribution pursuant to 35 USC 205 PROTECTED DATA O CRADA O Other specify 2 CONFERENCE PAPER PROCEEDINGS Conference Information title location dates Release date required no more than 5 years from date listed in Part I E above Ww DD YYYY 3 JOURNAL ARTICLE a TYPE O Announcement Citation Only O Preprint O Postprint b JOURNAL NAME SMALL BUSINESS INNOVATION RESEARCH SBIR DATA Release date required no more than 4 years from date listed in Part I E above MM DD YYYY SMALL BUSINESS TECHNOLOGY TRANSFER RESEARCH
10. defined as the contact length of the material in the roll bite L divided by the average material thickness ha Two equations are used to define the function for kc one for aspect ratios below ac and one for aspect ratios above ac where ac is determined by the intersection of the two equations Below ac the kg function takes non homogeneous compression into account where the plastic deformation zone extends outside of the region defined by the arc of contact The graph of the following two equations is shown in Figure 16 TRP 0040 Final Report 16 March 30 2005 k bl a cl fora lt a 2 20 ko 2a2 a b2 0 t c2 fora gt a 2 21 Resistance to Deformation Geometric Factor Geometric Factor Qc 2 3 4 5 Arithmetic Average Aspect Ratio Figure 16 Resistance to Deformation Geometric Factor The temperature factor kr is a function of the temperature difference between the selected Normalized Temperature Tx and the material temperature The graph of the following two equations for the temperature factor is shown in Figure 17 k 1 b1 Ty T for T gt Ty 2 17 k 214 b2 T T for T lt Ty 2 18 Resistance to Deformation Temperature Factor Tn x o o G Lu o x 3 x o a o Lr 1000 1100 1200 Material Temperature C Figure 17 Resistance to Deformation Temperature Factor TRP 0040 Final Report 17 March 30 2005
11. indicate Version 5 0 or greater Platform operation system O Postscript 4 IF COMPUTER MEDIUM OR AUDIOVISUAL MATERIAL a Quantity type specify b Machine compatibility specify c Other information about product format a user needs to know Transmission Information 1 STI PRODUCT IS BEING TRANSMITTED a Electronically via E Link b Via mail or shipment to address indicated in award document Paper product CD ROM diskettes video cassettes etc 2 INFORMATION PRODUCT FILE NAME of transmitted electronic format EditedTRP0040FinalReport PART Ill STI PRODUCT REVIEW RELEASE INFORMATION To be completed by DOE A STI Product Reporting Requirements Review O 1 THIS DELIVERABLE COMPLETES ALL REQUIRED DELIVERABLES FOR THIS AWARD O 2 THIS DELIVERABLE FULFILLS A TECHNICAL INFORMATION REPORTING REQUIREMENT BUT SHOULD NOT BE DISSEMINATED BEYOND DOE B Award Office Is the Source of STI Product Availability O THE STI PRODUCT IS NOT AVAILABLE IN AN ELECTRONIC MEDIUM THE AWARDING OFFICE WILL SERVE AS THE INTERIM SOURCE OF AVAILABILITY C DOE Releasing Official O 1 I VERIFY THAT ALL NECESSARY REVIEWS HAVE BEEN COMPLETED AS DESCRIBED IN DOE G 241 1 1A PART Il SECTION 3 0 AND THAT THE STI PRODUCT SHOULD BE RELEASED IN ACCORDANCE WITH THE INTELLECTUAL PROPERTY DISTRIBUTION LIMITATION ABOVE Release by name Date M D YYYY E Mail Phone AISI DOE Technology Roadmap Program
12. microalloying elements Figure 18 is a graph illustrating the effect of changing carbon content of the Shida flow stress Shida s Flow Stress from Carbon Content T n 0 0 o A Ld o z L 800 900 1000 1100 1200 1300 Temperature C Figure 18 Shida Flow Stress as Function of Carbon Content The Medina flow stress model was developed by S F Medina and C A Hernandez in 1996 This model can be applied to C Mn steels as well as those containing microalloys TRP 0040 Final Report 18 March 30 2005 such as Vanadium V Titanium Ti and Niobium Nb A graph of the Medina flow stress for a HSLA 50 grades is shown in Figure 19 Medina s Flow Stress HSLA 50 C1 eo KI a 0 0 o A o z S i 900 1000 1100 1200 1300 Temperture C Figure 19 Medina Flow Stress for HSLA 50 2 3 4 Added Temperature Tuning Coefficients The ability of the HSMM to accurately simulate rolling loads and final mechanical properties is directly dependent on its ability to accurately simulate the correct material temperature evolution through the hot mill Temperature evolution in the material mainly involves the effects of radiation conduction to the work rolls conduction to water sprays and heating from deformation Although the HSMM requires the user to input a number of parameters that characterize the mill equipment and operating conditions there will always be a set of unaccountable fac
13. of flow stress If the force model is using one of the flow stress methods and it is not providing accurate force predictions the difficulty is determining which flow stress coefficients to adjust To simplify the calibration procedure it was decided to only adjust the flow stress based on temperature and to let the HSMM calculate its own calibration coefficients for each grade By entering measured roll bite entry temperatures and rolling forces into the HSMM for one or more rolling schedules of the same grade the flow stress calibration procedure can be initiated by the click of a button This procedure calculates the ratios of the measured to the calculated rolling forces and then performs a second order polynomial regression on this set of ratios vs temperatures to determine the A B and C coefficients for the flow stress tuning multiplier An example regression calculation and graph is provided in Figure 23 and the flow stress calibration screen is shown in Figure 24 TRP 0040 Final Report 21 March 30 2005 Flow Stress Multiplier A T B T C 2 18 Temp Fmeas Fcalc Ratio m c 1225 1505 1500 1 0033 1220 1750 1735 1 0086 1210 2135 2164 0 9866 1200 2080 2099 0 9909 1180 2165 2206 0 9814 1150 2215 2243 0 9875 1050 2630 2769 0 9498 1030 2590 2711 0 9554 1005 2410 2549 0 9455 990 2095 2228 0 9403 970 1690 1802 0 9378 900 950 1000 1050 1100 1150 1200 1250 950 1450 1562 0 9283 Figure 23 Flow Stre
14. on the Runout Table In cases where transformation did not fully occur an empirical equation was employed to predict the final ferrite grain size and final ferrite fraction In HSMM version 6 2 this empirical equation was removed and the transformation prediction equations used for the Runout T ble are extended for use in the coiler In this way the correct cooling path is used to more accurately predict the transformation conditions in the coiler 2 4 4 Improved Elongation Calculation In the HSMM version 4 0 for the eight base grades the elongation was calculated as a function of the tensile strength defined by two straight lines Plant data showed that for the low tensile strength grades the elongation was being under predicted A power curve shown in Figure 30 was fit from plant data and introduced into version 6 2 to improve the elongation calculations especially in the lower tensile strength range TRP 0040 Final Report 27 March 30 2005 Elongation 7085 T 0 88 l c s 2 O c TT 400 600 800 Tensile Strength MPa Line 1 Line 2 Curve Fit Figure 30 New Elongation Curve 2 4 5 Improved Vanadium Precipitation Strengthening Calculation For HSMM version 6 2 a chemistry based Vanadium precipitation strengthening model was developed Version 4 0 provided only a constant value for potential precipitation strengthening that was independent of the Vanadium content After combining with Titanium any
15. 1 nodes See Figure 15 A new set of tunable thermal models were introduced for calculating bulk average temperature changes through the mill but the same microstructure models were applied Because the single node method dramatically reduces the number of calculations calculation time is typically around 5 to 10 seconds Both methods calculate data for the head middle and tail of the work piece and each method is completely independent of the other and is calibrated with separate tuning coefficients 2 3 1 1 Radiation Loss ATrad C 2 1 h 1 w S e p Cp T 273 15 4 Tamb 273 15 4 At 2 13 where S Stephan Boltzman constant emissivity 2 3 1 2 Roll Conduction Loss ATwrc C 4 k p Cp havg T Tr sqrt L x a v 2 14 where k 7 roll conductivity a roll diffusivity 2 3 1 3 Deformation Gain ATmec C K nm p Cp In hl h2 10 6 2 15 nm a b exp c K p Cp In hl h2 10 6 2 3 1 4 Water Spray Loss ATwat C 2 k p Cp h T Tw sqrt WatCL 2 a v 2 16 TRP 0040 Final Report 15 March 30 2005 where k material conductivity WatCL contact length of the water spray a material diffusivity 2 3 4 5 Runout Table Spray Loss ATwat C 2 k p Cp h T Tw WatCL WatCLO v 2 17 Because the single node method can calculate results that are consistent with those from the multiple node method but much more rapidly it has proven to be a valu
16. 20 ooze oso oroo osoo ooo ocos oos oe ois oos Table 3 Chemistry Range c wn j P jJ s w J c vo j wo j ri Jj v A w j Data for approximately 50 coils of steel was evaluated Since the effort covered five different rolling mills differences in data gathering reporting terminology and testing were introduced Every effort was made to be as consistent as possible for selecting comparison points between mill data and HSMM calculated data The final analysis indicated that having the exact temperature reading or the exact force measurement or the exact whatever was not extremely important to the final mechanical property results These measurements could include their own natural margin of error and the HSMM could still predict with very acceptable accuracy the tensile strength of the piece being modeled If anything the variation in data measurement collection and testing provided a possible source of error that was not necessarily caused by the models but observed when comparing actual versus predicted results 3 3 Results The measured parameter that deviated the most from the predicted value was the final ferrite grain size On a percentage basis when comparing actual versus calculated the final ferrite grain size comparison varied from as little as a 196 error to as much as a 5096 error However even though the final mechanical property calculations are partially grain size dependent the results did n
17. DO z 2 01 p 1 of 2 UNITED STATES DEPARTMENT OF ENERGY DOE OMB CONTROL NO Announcement of Scientific and Technical Information STI 1910 1400 For Use By Financial Assistance Recipients and Non M amp O M amp l Contractors PART I STI PRODUCT DESCRIPTION To be completed by Recipient Contractor STI Product Identifiers 1 REPORT PRODUCT NUMBER s None 2 DOE AWARD CONTRACT NUMBER s DE FC36 971D13554 3 OTHER IDENTIFYING NUMBER s None Sponsoring DOE Program Office Office of Industrial Technologi Subject Categories list primary one first 32 Energy Conservation Consumption and Utilization Keywords Steel Hot Strip Mill Computer Modeling Description Abstract The Hot Strip Mill Model HSMM is an off line PC based software B Recipient Contractor model originally developed by the University of British Columbia UBC INTEG process group 11279 Perry Highway Suite 107 Wexford PA and the National Institute of Standards and Technology NIST under 15090 the AISI DOE Advanced Process Control Program The HSMM was C STI Product Title developed to predict the temperatures deformations microstructure Validation of the Hot Strip Mill Model evolution and mechanical properties of steel strip or plate rolled in a D Author s hot mill INTEG process group undertook the current task of Richard Shulkosk enhancing and validating the technology With the support of 5 North David Rosberg American steel producers INTEG process group tested
18. Figure 35 Yield Strength Comparison Figure 36 Tensile Strength Comparison 33 Figure 37 Ferrite Grain Size Comparison sess eene eene eene ene ehem rtr nr eren nnne 34 LIST OF TABLES Table 1 Mill Configurations of Supporting Steel Companies eee 31 Table 2 Processing Parameter Ranges esses enne en nennen nene eren n nnne 31 Table 3 Chemistry Range reete rt e eei ette de E eR OP tas dive pac Eo rere 32 Table 4 Statistical Analysis of Comparison between Actual and Calculated 34 Please note that the Appendices noted in the Table of Contents are not included in the DOE submission due to Intellectual Property and Confidentiality issues TRP 0040 Final Report vii March 30 2005 EXECUTIVE SUMMARY The Hot Strip Mill Model HSMM is an inventive off line PC based software model originally developed by the University of British Columbia UBC and the National Institute of Standards and Technology NIST under the AISI DOE Advanced Process Control Program from 1993 1998 The HSMM was developed to predict the temperatures deformations microstructure evolution and mechanical properties of steel strip or plate rolled in a hot mill In 2001 INTEG process group inc undertook the current task of enhancing and validating the technology developed by UBC The objective was to test upgrade and validate the core mode
19. Final Report 0040 VALIDATION OF THE HOT STRIP MILL MODEL by Richard A Shulkosky David L Rosburg Jerrid D Chapman March 30 2005 Work performed under Cooperative Agreement No DE FC36 971D13554 Prepared for U S Department of Energy Prepared by American Iron and Steel Institute Technology Roadmap Program Office Pittsburgh PA 15220 DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government Neither the United States Government nor any agency thereof nor any of their employees makes any warranty express or implied or assumes any legal liability or responsibility for the accuracy completeness or usefulness of any information apparatus product or process disclosed or represents that its use would not infringe privately owned rights Reference herein to any specific commercial product process or service by trade name trademark manufacturer or otherwise does not necessarily constitute or imply endorsement recommendation or favoring by the United States Government or any agency thereof The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof This report has been reproduced from the best available copy It is available in paper copy and electronic format Number of pages in this report 48 DOE and DOE contractors can obtain copies of this report FROM Offi
20. MM to a certain level of usability was completed during the 3 Quarter of 2001 INTEG then released to the participants on August 4 2001 an updated version of the HSMM Phase 2 was to flow chart document and identify the inputs and outputs of each module or sub module for the current version of the HSMM Although some areas of the model were difficult to document due to limited information this phase was completed as much as practical during the 1 Quarter of 2002 and was to be completed during phases 4 and 5 when additional information was available Phase 3 was to validate each sub module but validation of each sub module using alternate models or plant data was not possible due to the design of the original model Instead based upon previous tests and published results of the model by the steel companies and UBC an evaluation of the modules as a whole was completed as much as practical during the 1 Quarter of 2002 Phase 4 involved the integration of the existing and new modules to make a cohesive model capable of covering all the needed functions to properly predict the temperature evolution TRP 0040 Final Report viii March 30 2005 forces microstructure evolution and final mechanical properties This task was completed and validated with an initial set of data in the 4 Quarter of 2002 Phase 5 involved the validation of the model and was completed in the 4 Quarter of 2003 Excellent agreement was obtained between the actua
21. TEG completed an extensive validation of the HSMM version 6 0 using a variety of grades of steel rolled under a variety of processing conditions and from a variety of rolling mills Four of the Enhancement Group companies providing data to validate the HSMM encompassed five rolling mills of various configurations Table 1 Company Area Retention Area Table otis 68 Hot Strip 1 Reversing Heat 7 Stand 19 Banks Dofasco Mill Stand Retention Tandem Mill of Coilers Panels Headers amp 1 148 Plate 1 Reversing None 1 Stand 4 Banks 1 Up Coiler Stelco Mill Stand Steckel Mill of Hamilton Headers Cooling Bed 2050mm Hot 1 Reversing Coil box 5 Stand 6 Banks 2 Down Stelco Lake SN Eri Strip Mill Stand Tandem Mill of Coilers e Headers US Steel 80 Hot Strip 5 Continuous None 6 Stand 20 Banks 2 Down Mill Stands Tandem Mill of Coilers Irvin Works Headers Weirton 54 Hot Strip 1 Rev Stand Heat 7 Stand 18 Water 2 Down Mill amp 1 Cont Retention Tandem Mill Walls Coilers Steel Stand Panels Table 1 Mill Configurations of Supporting Steel Companies 3 2 Plant Data The data supplied for the HSMM validation covered a variety of thicknesses speeds finishing temperatures coiling temperatures tensile strengths and amount of water used on the run out table Some variation in the chemistry within the microstructure grade families was also introduced The steel companies provided engineering logs data s
22. able addition for making the HSMM more efficient for the user The multiple node method is still available when the user requires the detailed temperature and microstructure profiles through the material thickness 2 3 2 Added Resistance to Deformation Force Model The NIST flow stress calculations in version 4 0 utilized a series of equations initially developed by NIST These equations are dependent on temperature austenite grain size strain and strain rate with associated coefficients that were developed for each of the eight characterized steel grades For version 6 2 a resistance to deformation force model was added to allow the user to generate a curve calculated from existing rolling mill data The resistance to deformation of the rolled material Kw is defined as the total roll separating force F divided by the projected area A W L between the work roll and the work piece when rolled without tension F Ky 2 18 When the material s microstructure restoration process time is shorter than the gap time between rolling passes the resistance to deformation depends mainly on the temperature of the rolled material and the geometry of the roll bite Therefore it is defined as the product of the normalized resistance to deformation Kw a geometric factor kc and a temperature factor kr Ky Ky ke ky 2 19 The geometric factor kg is a function of the average aspect ratio in the roll bite The aspect ratio is
23. ailable for plate products to be sent after the Runout table for simulation of radiation and convection cooling at the mill ambient temperature Simulation of forced convection however was not included 2 3 Improved Flexibility Several of the enhancements to HSMM version 6 2 originated from the need to provide flexibility to the user in making choices and adjustments to help improve the model s results and handle more processing conditions 2 3 4 Added Single Node Calculations The HSMM version 4 0 used the implicit finite difference method for calculating temperatures at multitude nodes through the thickness down the center of the work piece This calculation method has been preserved in version 6 2 and calculates 101 nodes TRP 0040 Final Report 14 March 30 2005 through the steel thickness and 10 nodes through each top and bottom scale layer Because the total calculation time for a complete hot mill simulation using this multiple node approach can be 2 to 3 minutes depending on computer speed and the complexity of the mill configuration a single node model was introduced to allow for rapid calculations Single Node Thru Full Slab Thickness Figure 15 Single vs Multiple Node Calculations The single node method calculates all the same thermo mechanical and microstructural parameters as the multiple node model but only as one average value for the entire thickness instead of the multiple node method s 12
24. an equation that is a function of temperature and a tuning factor A Separate tuning factors are applied to the single node and multiple node models TRP 0040 Final Report 23 March 30 2005 2 4 Improved Microstructure Mechanical Properties Calculations 2 4 4 Allow Chemistry Adjustments The microstructure evolution and final mechanical properties models developed by UBC for version 4 0 were based on eight grades of steel with specific chemistries These models contained equations with coefficients determined from lab tests Many of these equations were chemistry dependent but the chemistry values applied to these equations were fixed for each of the eight grades that could be selected The first step in version 6 2 in making the microstructure evolution models more flexible was to allow the user to enter the actual chemistry of the grade he she is simulating After entering the actual User Chemistry as shown in Figure 26 the user then selects the grade with chemistry closest to the entered chemistry The grades available for selection include the nine sample grades and any others that have been built using GradeBuilder as described in Section 2 4 2 By allowing the user to enter a chemistry that differs somewhat from the selected grade s chemistry the microstructure results are generally improved If the user enters chemistry values that deviate significantly from the selected grade a message is displayed that warns the user that the m
25. and 2 Stand 2 Stand 2 Figure 7 Speed Profile and Transfer Times between Mill Stands 2 2 2 Force Model HSMM version 4 0 used the NIST developed equations and coefficients to calculate flow stress s and the traditional Sim s geometric factor Qp to calculate the rolling force F o 0 JRMAW 2 1 JB However when rolling thick product in the early roughing passes deformation beyond the arc of roll contact also known as the peening effect occurs that results in higher rolling forces To compensate for this effect an adjustment was made to the Sim s geometric factor as shown in Figure 8 This adjustment is a function of the roll bite aspect ratio a contact length L divided by average thickness Qp 0 7924 1 778 exp 2 148 a for a lt 1 0 2 2 Qp Force Geometric Factor Peening Effect Geometric factor 4 6 Aspect Ratio Figure 8 Force Geometric Factor with Peening Effect TRP 0040 Final Report 7 March 30 2005 2 2 3 Motor Power Calculations In addition to roll separating force limitations other concerns in a hot mill are the limits from the mill stands motor power and torque It is a futile exercise to develop a new rolling practice for a product that achieves the target mechanical properties but the mill doesn t have the power to produce it HSMM version 6 2 was enhanced with the addition of optional motor power and torque calculations as shown in Figure 9 These ca
26. as on going enhancements for the ROT the University of Pittsburgh BAMPRI in particular Dr Anthony DeArdo and Dr Isaac Garcia for conducting an analysis on the model and the consultants who supported various tasks in the development of the enhanced version including Dr Vladimir Ginzburg Naum Kaplan Robert Ballas Steven Lechuk and Dr Daging Jin the lead researcher for the original project now an employee of The Timken Company TRP 0040 Final Report V March 30 2005 TABLE OF CONTENTS FORWARD oan estere eu hose deal Leann us Desk ti E E A NEA e ben io des V EXECUTIVE SUMMARY ennhe aent aa e AS R ARR NR VEU ERREUR pue NN UE Rd Vili I TOJU UONE c dod aR aioe altis AiR cin a uen Mite ute SLE te aa Rie df Si eae 1 2 a HSMM Enh ncements eoo eue Nu pae tesco sada seca Bop ana ee eens eens 1 2 1 Improved Software Engineering sesessssssssesssssserssersssetesstesseessersseeesseeessresseesseesseeesseee 1 2 1 1 Users Interface emon si cei R A E LL Raf 1 2 1 2 Fortran Gode MEM IP C EE a AS 3 2 2 Improved Practicality in Thermo Mechanical Calculations eese 5 2 241 Material beo sra tct NE M T 6 2 2 2 OCS Modele astu et se ai ae gin cu a one Eu IE AM ETE Sh aaa 7 2 2 3 Motor Power Calculations ssnin iaie este raos en seS 8 2 2 4 Mad EC anges siis ectetur aN E N eet SAUL e 10 TDS Let CHECKING c gated 12 2 2 6 Added Crown and Shape Models 5 eret der teen aceite er tee etat ead dae 13
27. ble speeds Calculated parameters that are limit checked e Material lengths and widths Bite angles Rolling forces Rolling torques Motor output powers Edger buckling Error and limit warning messages are displayed to the user as shown in Figure 13 TRP 0040 Final Report 12 March 30 2005 HSMM Error Log xi File Print Description AAd Warnings Warning 1 Limit Warning RR 2 Head Current Maximum Limit exceeded Middle Current Maximum Limit Warning 2 Limit Warning RR B Head Current Maximum Limit exceeded Middle Current Maximum Limit Warning 3 Limit Warning RR Middle Current Maximum Limit exceeded Tail Current Maximum Limit Warning 4 Head Force Maximum Limit exceeded Middle Force within 5 of limit Limit Warning Figure 13 Error and Warning Messages 2 2 6 Added Crown and Shape Models Even though the hot mill can roll a particular product within its own limits the product may not be salable if its shape flatness is unacceptable Another level of practicality was added to version 6 2 with the incorporation of the crown and shape models These models can be turned on by the user to calculate the crown profile on the work piece after each reduction The exit crown of the work piece is calculated from the deflection of the roll stack due to the rolling load the crowns on the work and backup rolls and any applied mechanical bending forces To maintain a flat prod
28. can files rolling speeds forces temperatures etc and laboratory data yield strength tensile strength elongation grain size etc Data was obtained for seven of the eight HSMM microstructure grades To further improve the accuracy of the model the actual chemistry of each piece was used for the microstructure calculations Table 2 displays the approximate range of processing parameters and Table 3 the range of key elements of the steels utilized Finished Thickness Strip Finished Thickness Plate Finishing Temperature Range 800 C to 950 C Coiling Temperature Range 600 C to 725 C Yield Strength Range 200MPa to 650MPa Tensile Strength Range 300MPa to 700MPa Table 2 Processing Parameter Ranges TRP 0040 Final Report 31 March 30 2005 E 36 DASK 0 025 0 26 0 009 0 011 0 021 0 051 0 006 0 025 0 004 0 064 0 40 0 020 0 030 0100 0 100 0 020 0 002 0 008 0 008 0 050 0 010 IHSLA V 0 050 0 60 0 007 IHSLA Nb Min 0 050 0 55 0 100 0 020 0 010 0 020 pe mac 0030 105 oms 0280 oroo ooo soso oso 0006 0008 0000 omo HSLA Nbi 80 0 060 1 25 0 100 0 020 0 029 0 006 0 065 0 030 0 005 P ma ooo 150 ooze osos o100 Pos oos ones ooso ors Foo IF NbRich 0 05 0 005 0 040 0 060 0 008 0 045 0 020 0 003 pe ma oes 020 ooz oso ion 0100 oso owas oes oos ness onos IF NbLean 0 10 0 050 0 020 pee was oaos 0
29. ce of Scientific and Technical Information P O Box 62 Oak Ridge TN 37831 615 576 8401 This report is publicly available from Department of Commerce National Technical Information Service 5285 Port Royal Road Springfield VA 22161 703 487 4650 And at the following website www osti gov bridge TRP 0040 Final Report li March 30 2005 Report Documentation Page Title and Subtitle Validation of the Hot Strip Mill Model Authors Richard A Shulkosky David L Rosburg Jerrid D Chapman Performing Organization Names Address INTEG process group inc 11279 Perry Highway Suite 107 Wexford PA 15090 USA Abstract The Hot Strip Mill Model HSMM is an off line PC based software model originally developed by the University of British Columbia UBC and the National Institute of Standards and Technology NIST under the AISI DOE Advanced Process Control Program from 1993 1998 The HSMM was developed to predict the temperatures deformations microstructure evolution and mechanical properties of steel strip or plate rolled in a hot mill In 2001 INTEG process group inc undertook the current task of enhancing and validating the technology developed by the UBC With the support of the AISI DOE and five North American steel companies INTEG embarked upon a multi year plan under a DOE TRP project to upgrade enhance and validate the model referred to as the AISI Hot Strip Mill Model HSMM version 4 The steel compan
30. e Properties Austenite Processes Transformation Mechanical Properties Flow Stress Function Selection Equation Strain Components C Peak Strain UBC Show Eqn Critical Strain C Retained Strain Recrystallization Boundary Conditions C Potential for MD Recryst Zener Holloman modified x Show Eqn Lim Potential for MD Recryst Zener Hollomantmoditied x Show Eqn C No Reeryst Temperature Manual x Show Eqn Static Recrystallization Kinetics 0 1 8 3 4 5 5 7 C Time for 50 Recrystallization Avrami Show Eqn Time sec C Fraction Recrystallized Avrami x Show Eqn icm GSfunl mm 0 f Reciystallized Grain Size UBC x Show Eqn Meta Dynamic Recrystallization Kinetics C Time for 50 Recrystallization Avrami Show Eqn Fraction Recrystallized Avrami C Recrystalized Grain Size UBC z Show Eqn 3 9E 05 Austenite Grain Growth 2 C Grain Growth Factor AIN Pinning Show Eqn 2 EBAE 19 Grain Growth after Recryst uec Show Eqn Austenite Precipitation Austenite Precipitation AIN Precip Show Eqn Description Figure 27 GradeBuilder Screen Within GradeBuilder the user also has the ability to select between two different methods of determining thermal properties of the grade being built Method 1 UBC see Figure 28 has the thermal properties split into three phases austenite ferrite and pearlite curves This method will accurately calcula
31. each reduction and warns the user whenever the calculated values exceed the maximum limits or are within 5 of the limit 2 2 4 Width Changes Besides developing the proper mechanical properties the purpose of hot rolling is to reduce the thickness of the slab to the final sheet or plate thickness while making the product length proportionately longer However in flat rolling the material also gets wider due to spreading To counteract spreading many hot mills have edging equipment to take TRP 0040 Final Report 10 March 30 2005 width reductions usually in the roughing stage while the work piece is still thick enough to prevent buckling HSMM version 6 2 has incorporated models for spreading edging and spreading after the edging Modeling the correct width results in better force predictions at the horizontal stands as well as allowing the HSMM to be used for edging capability studies Spreading due to horizontal rolling is a function of width and thickness into the roll bite W1 and HI thickness exiting the roll bite H2 and roll diameter D Wi Wi WiY WiY mn ny m A pe m w 2 Spread W1 1 2 10 i a Un E H2 Een where coefficients c1 c2 c3 and c4 have been determined During width reduction by edging some of the material will result in elongation of the work piece and the remainder will cause bulging at the material edges Rolling in a horizontal stand after edging will force some of the bulge
32. eeeeeecessensaneaeeeeeeeseeeeeaas 19 Figure 20 Single Node Thermal Model Tuning Coefficients eene 20 Figure 21 Multiple Node Thermal Model Tuning Coefficients eeeeneeeee 20 Figure 22 Chart of Calculated lines vs Measured dots Temperatures for Tuning 21 Figure 23 Flow Stress Multiplier Regression ccccccecsssesessecececececeesenenececececessesesueaeeeeeeeseeeeeeaas 22 Figure 24 Flow Stress Calibration Screen eeseesssccccccecessessnnececeeececeesssecaececececessessaneaeceeeeeeeeseeeaas 22 Figure 25 Plant Database Link ecirar a ise aine eE EERE E ERE Ra ee eren agni 23 Figure 26 User Chemistry Field c Ee e dee ebd cohobvuusee 24 Figure 27 GradeBuilder Sereen isai i ee a a a ae A a a 25 Figure 28 Thermal Property Selection by Phase UBC Method esee 26 Figure 29 BISRA Thermal Property Selection BISRA Method seen 2 Figure 30 New Elongation Curve c cccccccesssssssenececeeeeessesenececececessesssnaececececessessaneaeeeeeeeeeeeeneaas 28 Figure 31 Improvement in HSLA Vanadium Grade Yield Strength Predictions 29 Figure 32 Cooling Path on the Runout Table for Dual Phase Steels eeeseeeeeeee 30 Figure 33 Finishing Temperature Comparison Figure 34 Coiling Temperature Comparison 33
33. face to a plant database for importing data into new rolling schedules 4 5 Microstructure Guide The purpose of this document is to provide an understanding of the underlying methodologies used for microstructure modeling in the HSMM and how the user can best apply this model to his her grades of steel using the GradeBuilder Module 4 6 Technical Manual The document describes the thermo mechanical calculations that are performed in the HSMM and how they are applied in simulating a work piece rolling through an entire hot strip mill The equations and numerical methods that are used in these calculations are also provided TRP 0040 Final Report 35 March 30 2005 5 Conclusion With the release of version 6 2 the validation and enhancement goals of this project were successfully achieved in January 2005 At that time the HSMM had already been purchased by three steel producing companies located on three different continents They and the supporting steel companies continue to find outstanding value in the HSMM as a beneficial tool in saving them time and money for a variety of practical applications TRP 0040 Final Report 36 March 30 2005 Appendix A HSMM User Documentation The HSMM User Documentation as described in Section 4 is provided in the following files in PDF format e User Manual doc Getting Started doc Calibration Guide doc Client Database Link Instructions doc Microstructure Guide doc Technical Manual doc Flow
34. free Nitrogen combines with Vanadium in a 4 1 ratio The maximum strengthening that is available from precipitation is a function of the VN and excess vanadium VNeff Min Nfree 4 V 2 19 P S a VNeff b V VNeff 2 20 where coefficients a and b were determined The actual amount of precipitation strengthening is a function of the Shercliff Ashby aging curve as before An example of the improved results is shown in Figure 31 TRP 0040 Final Report 28 March 30 2005 Vanadium Grade Yield Strengths e Meas s New a Old Figure 31 Improvement in HSLA Vanadium Grade Yield Strength Predictions 2 4 6 Added Models for Dual Phase Steel For this enhancement UBC was contracted to perform the necessary lab tests to develop a microstructure model for hot strip rolling of Dual Phase Mo 600 steel The result of this work produced the following new models for this steel e Ferrite Transformation Model o Enhanced JMAK model o Enhanced ferrite grain size model e Bainite Transformation Model Martensite Transformation Model New Mechanical Properties Model Figure 32 shows the cooling path required to produce this grade See Appendix B for UBC report TRP 0040 Final Report 29 March 30 2005 QO formation JMAK Figure 32 Cooling Path on the Runout Table for Dual Phase Steels TRP 0040 Final Report 30 March 30 2005 3 HSMM Validation 3 1 Overview In 2003 IN
35. g Zone HTC Multiplier Zones 1 4 Ems Top Impingement Zone HTC Multiplier Zones 2 3 ies Top Spray Impingement Efficiency Multiplier NNNM Bottom Impingement Zone HTC Multiplier Zones 2 3 Low Coiling Temperature Coefficient Figure 21 Multiple Node Thermal Model Tuning Coefficients The HSMM can plot calculated temperatures as well as entered measured temperatures entered by the user Measured temperatures may be recorded in Engineering Logs or stored in the plant s database The source of these temperatures may be from pyrometer readings at various locations in the mill or they may be calculated by the plant s online Level 2 computer at each stand or pass From the HSMM temperature chart of calculated TRP 0040 Final Report 20 March 30 2005 vs measured values the user can adjust the thermal model tuning coefficients in an iterative process of running the model and adjusting the tuning value until the calculated values match the measured ones as shown in Figure 22 e LT o B o 2 E eo Station Pass Figure 22 Chart of Calculated lines vs Measured dots Temperatures for Tuning 2 3 5 Added Automatic Force Model Calibration Like the thermal models need for a tuning method to be more accurate the three flow stress methods needed a tuning method to make the force model more accurate All three methods consider the temperature strain strain rate and austenite grain size for their calculation
36. gth Comparison Tensile Strength Comparison ES Rare ee ne 800 ere i E Pa T Plain Carbon P FC Plain Carbon E 700 T E BA 7 AHSLA 1 E 54 l Interstial Free A Interstial Free E E 600 500 z A 2 E z tz 3 400 Z Z 8 5 S 300 ttt t 100 5t tt t t m tt 400 500 100 200 300 400 500 600 700 800 Measured MPa Measured MPa Figure 35 Yield Strength Comparison Figure 36 Tensile Strength Comparison TRP 0040 Final Report 33 March 30 2005 Ferrite Grain Size Comparison 20 Range Plain Carbon A HSLA Interstial Free Calculated HSMM microns fe E 10 15 Measured microns Figure 37 Ferrite Grain Size Comparison 3 4 Validation Summary As can be seen from the above charts and the statistical summary in Table 4 the HSMM has been validated using data from coils produced on a variety of mills and good agreement has been achieved for the variety of products and processing parameters covered When comparing the final results for tensile strength a very acceptable range of errors have been achieved with an average percent error calculated from the average absolute error of 3 03 or a 396 error With this type of performance the HSMM version 6 2 can be used for conducting a variety of off line analyses knowing that a proper trend and or relative prediction can be achieved Avg Absolute Error Avg Percentage Error Finishing Temperature 9 14 C 1 02
37. icrostructure results may be suspect CX Mn P iz Cr Mo Nb VX User Chemistry Grade Base Chemistry Figure 26 User Chemistry Field 2 4 Added GradeBuilder Module The next step in version 6 2 in making the microstructure evolution models more flexible was to allow the user to build his her own grade in addition to the nine sample grades The purpose of adding the GradeBuilder module to the HSMM was to change the user s view of the microstructure models from being a rigid black box to being an open configuration panel for building a new grade or modifying an existing grade GradeBuilder not only allows the user to see what equations and coefficients are used but allows him her to select which algorithms to use and adjust the coefficients The user can even write their own algorithms and select them for use with their own grade To build a new grade the sample grade that is closest to the new grade can be duplicated and given a new name Then the equations and coefficients for each microstructure process during the austenite phase phase transformation and final mechanical properties can be selected to best represent the microstructure characteristics of the new grade The austenite process selection screen of the GradeBuilder is shown in Figure 27 TRP 0040 Final Report 24 March 30 2005 Grade Edit Selection DOSK sample Save Grades Grade Management Grade Thermal Properties Grade Microstructur
38. into elongation and some of it will spread back as increased width and is called recovery Recovery is a function of previous width draft AW width and thickness into the edger W1 and H1 width exiting the edger W2 and edger roll radius Re c2 c3 c4 c5 e where coefficients cl c2 c3 c4 and c5 have been determined If the edger rolls are the grooved design type with a top and bottom collar and the material is at a thickness to fill the groove then the bulge created during edging will be forced inward from the edge The recovery that occurs after horizontal rolling will be less with grooved rolls and the edging process more efficient than with normal flat edger rolls as shown in Figure 12 TRP 0040 Final Report 14 March 30 2005 Relative Edging Efficiency v i _ z o A o A o o 2 o o Oo b o width draft mm Figure 12 Increased Edger Efficiency with Grooved Edger Rolls 2 2 5 Limit Checking In addition to the power checking that was described in section 2 2 3 HSMM version 6 2 has incorporated a system of checking both user entered and calculated values against maximum and or minimum limit values These limits are configured by the user and many are of these limits are optional A list of any limit violations is displayed to the user Entered parameters that are limit checked e Slab temperatures Slab dimensions Roll diameters Work roll speeds Ta
39. l Mill Configuration Options Help Roughing Mill Finishing Mill Runout Table Yy rs h Pa E aN A EE a aO a LEN S NS b d b db d S SU SM NM SA aA W Vu V Downcoiler Mill Configuration EX amp MPLE1 HSM Steel Type HSLA Nb TiBO Default Units SI Figure 1 User Interface for HSMM version 4 0 The HSMM version 6 2 utilizes a user friendly interface see Figure 2 allowing each mill to be accurately configured each rolling schedule to be set up in detail each grade of steel to be accurately characterized and the final results to be viewed charted reported and exported as needed The user interface is divided into the following main areas e The Mill Configuration Screen allows the user to set up the rolling mill to be used and includes the furnace area roughing area mills edgers sprays heat retention area coil box heat panels finishing area mills edgers sprays run out table and mill exit area e The Calibration Screen allows the user to calibrate the model for each grade of steel being simulated During the overall project set up the user selects a specific set of coefficients to be used for the grade of steel being processed via a specific rolling mill schedule e The Rolling Schedule Screen is used to enter the processing parameters of the piece being modeled and to view the results of the single node and multiple node calculations The screen allows the user to view and configure the Initial Data Pass Data
40. l and calculated values for tensile strength and yield strength Additional work under Phase 5 was completed in the 1 Quarter of 2004 and resulted in the addition of GradeBuilder which allows the user to develop and add new grades of steel by selecting or adding new algorithms and coefficients Additional work under Phase 5 was completed in the 4 Quarter of 2004 that included an upgrade to the ROT tracking and thermal models the addition of soft coupling of mill equipment and the implementation of basic equations for dual phase steels The successful result of this project was the final release of the Hot Strip Mill Model HSMM as version 6 2 This version allows users to easily set up their mill configuration simulate a rolling mill schedule and calibrate the model for a variety of grades of steel The enhanced HSMM was validated using a multitude of samples from the Enhancement Group steel companies Excellent agreement was obtained for comparisons between measured mechanical properties and those calculated by the HSMM Enhancement features incorporated into version 6 2 of the HSMM that have made it more flexible and practical to use include e Improved user interface e Ability to link all models and track the material through the entire mill Improved temperature and force modeling Ability to calibrate temperature and force models with plant data Ability to adjust microstructure calculation algorithms and coefficients The supporting
41. lculations are optional to the HSMM user because power calculations require a number of motor data parameters rated power RPMs maximum load ratio gear ratio of the gear box etc be input for each rolling stand Power Electrical Mechanical Torque at Shaft at Spindles Figure 9 Mill Stand Drive showing Motor Power and Torque Calculations Before calculating motor power the total rolling torque M is calculated from the rolling force P in kN and the lever arm a in mm and multiplied by 2 to consider both work rolls 2 P a __ kN m 2 3 1000 i The total rolling torque is affected when entry and or exit tension on the material is present In this calculation tension not only lowers the rolling force and therefore the rolling torque but entry tension S1 increases the rolling torque while exit tension S2 decreases it L2 a W L K su R 5 5 kN m 2 4 1000 1000 1000 1000 Sayg s the average specific tension in MPa Sag B 5 0 B 5 2 5 TRP 0040 Final Report 8 March 30 2005 Si h1 h2 S2 Figure 10 Roll Bite illustrating contact length L bite angle 6 roll force P and tensions S The lever arm is the distance from the work roll center line to a point located along the roll bite contact length L where the entire vertical force vector can be considered to exist for calculating the rolling torque see Figure 10 The lever arm is calculated f
42. ls used for predicting the temperature forces microstructure evolution and final mechanical properties of steel produced on a hot strip mill The scope of work includes validating and or replacing various sub models adding practical application functions updating the users interface to facilitate the ease of use of the model and to provide adequate documentation With the support of the AISI DOE and five North American steel companies INTEG embarked upon a multr year plan under a DOE TRP project to upgrade enhance and validate the model referred to as the AISI Hot Strip Mill Model HSMM version 4 The steel company participants Dofasco IPSCO Stelco US Steel Weirton Steel formed the HSMM Enhancement Group to provide input and support to the effort The project included a detailed review of each sub module of the model and a validation and or replacement of each sub module Practical application functions an updated user s interface to facilitate the ease of use of the model and adequate documentation was to be provided A five phase plan was developed to validate the Hot Strip Mill Model Phases 1 2 and 3 of the extended work plan were to conduct a technical audit of the model and to develop a plan to improve the model for practical applications Phases 4 and 5 were to develop validate and calibrate an enhanced version of the model with proper documentation advanced modules etc Phase 1 which undertook several tasks to bring the HS
43. ly introduces a degree of error in the accuracy and repeatability of the test but also introduces a variety of methods to report the results such as a Lower Yield Point 0 2 Offset or 0 5 Under Load thus creating some potential error in comparison using data gathered from multiple steel companies The following charts Figures 33 34 35 36 37 provide a summary of the comparison between the actual and calculated values for the temperature exiting the finishing mill the coiling temperature the yield strength the tensile strength and the ferrite grain size Range lines are added to the graphs to show a range of 20 C for the temperatures and 5 MPa for the yield and tensile strengths A fixed error range for the temperatures was used because the relative spread between the lowest and highest temperature was only about two hundred degrees For the mechanical property charts a percentage error range was used because the range from the lowest to the highest was about 400MPa Finishing Temp Comparison Coiling Temp Comparison c c z z a z 5 a 2 Calculated HSMM C tt 550 600 650 700 750 800 850 900 950 1000 Measured C Figure 33 Finishing Temperature Comparison Figure 34 Coiling Temperature Comparison Yield Stren
44. module input parameters Add calculation error checking to avoid crashes divide by zero square root of negative value exponent over or underflows e Update the code to Fortran 95 standard Figure 3 illustrates how the software was divided into individual modules to make maintenance of the software easier A comparison of the version 4 0 Fortran code in Figure 4 and the enhanced Fortran 95 code in Figure 5 shows the improvements that were made in readability and error checking TRP 0040 Final Report 3 March 30 2005 User Interface p rostructure Equations CH em a LN Temperature Z Radiation Conduction Convection Boling Z Flow Sprays Rolling lt Power Sages Seran Straf Rate J Stresses Deformation Modify Replace SIG1 SIG 9 81 REDF REDC NROLS3 100 0 DH HI H2 100 FRD DSQRT RD H2 DQRT DSQRT REDF 1 0D0 REDF PHI DTAN PI DLOG 1 0D0 REDF 8 0D0 FRD 0 5D0 1 DATAN DQRT FRD HNUET 2 0D0 RD 1 0D0 DCOS PHD H2 QP PI 2 0D0 DORT DATAN DQRT PI 4 0D0 1 FRD DQRT DLOG HNUET H2 0 5D0 2 DLOG 1 0D0 REDP P SIGI DSQRT RD DH QP ABD DABS P PO P IF ABD GT 1 0D 3 THEN RD R 1 0D0 C P DH P0 P GOTO 100 ENDIF Figure 4 Sample original code without error checking comments or descriptive names TRP 0040 Final Report 4 March 30 2005 Calculate the roll deformation force SQRT_PARAM
45. ot consistently show the same relative magnitude of error for tensile strength comparisons between actual and calculated This can be primarily explained by the error that occurs in the measurement of the ferrite grain size Since no uniform practices were issued any to all of the supporting steel companies prior to their submission of the grain size measurements a natural error in measurement can be expected However it is important to point out that the grain sizes calculated by the HSMM were indicative of the magnitude of the measured grain sizes For example one steel sample had a measured grain size of 7 9 microns while the model predicted a final ferrite grain size of 4 9 microns Although this was almost a 40 error the magnitude of the grain size prediction was in an acceptable range because the tensile strength prediction was within 1 The ultimate goal of the HSMM is to predict the final mechanical properties of the steel being rolled in a hot mill Due to the variations mentioned above it was decided that the best or most consistent and reliable parameter that could be used to measure the model s performance would be the tensile strength The tensile strength is viewed as the best measure of performance because this test is the most repeatable in the lab and thus has the least deviation error built in on the measurement side The yield strength calculation on TRP 0040 Final Report 32 March 30 2005 the other hand not on
46. own in Figure 25 T Plant DB Link Wizard This interface prodvides the capability to import data from a plant database It is required to review the supplied DB linking documentation to assure your plant database is setup properly for this tool Connection Import Selections Import 5 I t Stat Import to this project Select Project esed et 1 Import Started C Temp test_db_link hsm inp i A T 2 Starting import of schedule sched1 Select calibration module to import to dmpot DUSK 3 Finished import of schedule sched1 Figure 25 Plant Database Link 2 3 7 Handle Low Coiling Temperatures The runout table model for HSMM version 4 0 was developed and tested for normal coiling temperatures down to 550 C For simulating certain advanced high strength steels AHSS much lower coiling temperatures are required to produce the desired bainite and martensite phases It was discovered during HSMM simulations that the runout table models for both the multiple node and single node models could not be tuned to simultaneously produce the intermediate temperatures and low coiling temperatures that were actually observed in plant trials The plant data showed there was very rapid cooling of the material at temperatures below 450 C To increase the heat transfer in this low temperature region a multiplier was introduced into version 6 2 that could be tuned to match actual data This low coiling temperature multiplier is
47. rea such as the Roughing Mill Finishing Mill Runout Table etc The interface was an aid for the preparation of input files before launching control to one of the Fortran modules The graphical user interface was designed in Microsoft s Visual Basic 5 0 2 1 4 User s Interface The User s Interface consists of Microsoft compatible Windows screens menu selections buttons data entry and display fields charts etc that the user interacts with for program control and exchanging data with the Fortran calculation software Because Microsoft was encouraging its Visual Studio customers to migrate up to its new NET Framework environment it was an obvious decision to keep up with the current technology and completely redesign the User s Interface screens using NET Some of the changes that went into the redesigned User s Interface software were e Divide the Interface screens into five main functional areas o Mill Configuration o Grade Calibration o Rolling Schedules o Data Exporting Reporting o GradeBuilder e Switch from saving data in text files to Microsoft Access database files e Add the ability to import rolling schedule data from the plant s database e Exchange data with the Fortran dynamic link library via well designed large data structures Figure provides a picture of the main User s Screen for HSMM version 4 0 TRP 0040 Final Report 1 March 30 2005 v4 0 0 Hot Strip Mill Configuration EXAMPLE1 HSM File Mode
48. rom the lever arm coefficient m that is a function of the roll bite geometry roll diameter D and exit thickness h2 m L 2 6 2 7 m c1 e2 exp 2 2 where coefficients c1 c2 and c3 have been determined A graph of the lever arm function is provided in Figure 11 TRP 0040 Final Report 9 March 30 2005 Lever Arm Coefficient 0 8 o D lever arm coefficient m oO on o w o N o N o B o o o D 2 h2 Figure 11 Lever Arm Coefficient m as a Function of Roll Bite Geometry The torque at the motor shaft is the torque at the rolls after transfer through any gear box with a gear ratio GR and a mechanical efficiency n Because there are frictional losses in a gear box it has an efficiency 1 that is normally between 0 9 and 1 0 If there is no gear box the gear ratio 1 0 and n 1 0 M M motor 2 8 GR n The mechanical power that must be delivered at the shaft of the motor to roll the material is a function of the torque at the roll and the roll angular speed The mechanical power is compared to the motor rated power to determine the load ratio Because of the electrical losses in the motor the electrical power volts x amps input to the motor is greater than the mechanical power output ok ky M 2i M v 1000 2 9 R n If the power calculations are turned ON HSMM version 6 2 calculates the required power and torque for
49. s a permanent record to better understand the program s logic flow Instead of building a series of executable programs the Fortran source code was built into a single dynamic link library dll file of individual modules that could be called from the User s Interface 2 2 Improved Practicality in Thermo Mechanical Calculations The HSMM version 4 0 ran as seven separate models for the various hot mill areas and mill configuration types Roughing Mill Model Reversing Roughing Mill Model Coil Box Model Finishing Mill Model Runout Table Model Deformation Model Down Coiler Model and Steckel Mill Model The results of each model were not linked to the input of the next successive model It was discovered that the HSMM version 4 0 lacked the ability to simulate certain hot mill equipment and normal processing conditions It was also possible for the HSMM to simulate impossible overly aggressive reduction TRP 0040 Final Report 5 March 30 2005 conditions To improve the practicality of the HSMM several enhancements were incorporated relating to linking all the models together for the entire hot mill adding various limit checking and simulating additional pieces of mill equipment 2 2 4 Material Tracking As mentioned above version 4 0 ran each mill area rougher finisher runout table coiler as separate models In version 6 2 the entire hot mill is simulated sequentially from drop out of the reheat or tunnel furnace to exiting into
50. ss Multiplier Regression C Prose Fies SYM vs 2 projects Semple B OF Jue For Enhancement Group Use Only Calibration and Grade Data OQSK trdowmaton Gea Seinnor Force Model Galechon Caite gun Cosihiceens _ _ _ _ ai ow w0 1100 UO 1 00 Temper ate C Figure 24 Flow Stress Calibration Screen Once a grade is calibrated with its own set of A B and C calibration coefficients the flow stress multiplier function produces multiplier values within a range around 1 0 that adjust the flow stress and force calculations to better match the measured forces New rolling schedules created for the grade can be expected to have improved force predictions TRP 0040 Final Report 22 March 30 2005 2 3 6 Added Plant Database Importing The ability to import data from a plant database and automatically create a Rolling Schedule was added in version 6 2 This enhancement allows the user to simulate a previously rolled coil without having to manually enter the rolling parameters such as thicknesses speeds measured forces etc To implement this feature the user must set up an ODBC connection to the plant database via Administrator Tools in his Windows Control Panel Then by invoking a query into the plant database three tables of data must be generated in a format required by the HSMM Once the tables are created the HSMM Database Link utility screens are used to import data and create new rolling schedules as sh
51. steel companies have found outstanding value in the HSMM in saving them time and money for a variety of practical applications The HSMM continues to be marketed and sold on a global basis as the industry s leading PC based off line model for helping steel producers and researchers improve the rolling process TRP 0040 Final Report ix March 30 2005 1 Introduction This report provides a summary of the Enhancements Section 2 Validation Section 3 and Documentation effort Section 4 that INTEG performed over the life of the entire Validation of the Hot Strip Mill Model project Detailed user s manuals and technical documentation that are provided in Appendices A and B are confidential Protected Metals Initiative Data and are available only to the project participants 2 HSMM Enhancements The enhancements that were identified as necessary improvements to the HSMM were related to four main categories e Software Engineering section 2 1 e Practicality in Thermo mechanical Calculations Section 2 2 e Improved Flexibility Section 2 3 e Microstructure Mechanical Property Calculations Section 2 4 2 4 Improved Software Engineering The Hot Strip Mill Model version 4 0 as delivered by UBC was a stand alone Windows 95 application It was a composition of a graphical User s Interface and about eight Fortran executables programs and numerous text data files Each of the Fortran modules represented a particular process a
52. steel producers and researchers improve the hot rolling process TRP 0040 Final Report iv March 30 2005 FORWARD INTEG process group inc would like to thank the American Iron and Steel Institute and the Department of Energy for their continued financial support over the past four years enabling the HSMM to be enhanced and validated so that it is a practical tool for the steel industry The assistance and support received from Joe Vehec Director of the AISI Technology Roadmap Program over the years was very valuable and appreciated Larry Kavanagh and the staff at the AISI in Washington D C are also warmly thanked for their continued support throughout the project We would particularly like to acknowledge the efforts of Keith Barnes Mark Fenton Brian Joel and Tibor Turi of Stelco Brian Nelson and J J Fitzpatrick of Dofasco Matt Merwin and Eugene Nikitenko of U S Steel Cache Folkman Shaojie Chen and Steve Yocom of IPSCO and Rich Frey of Weirton Steel now part of ISG for the invaluable input and leadership they have provided over the course of the four year project We are also grateful to all the HSMM Enhancement Group companies for providing operating data and for their constructive feedback We would like to recognize the strong technical contributions of UBC in particular Dr Matthias Militzer and Dr Vladan Prodanovic for providing background information on the model adding new models for a new dualphase steel as well
53. te Doi de HEC PdER 31 3 1 OVERVIEWS e a a a a T stun canes NNA 31 3 2 Plant Data cm MN RR T ERN 31 3 3 RESULTS m ea E EE E E A aaa aTe 32 SA Validation Summary ostrea nU TENER EST E EE o EEE o DANN Ea Tii 34 4 HSMM User DocumehttatiQh uiu oett in Ren EEE SAT RE ESES 35 4 1 User s Mami pe nesurenar ne enai iia e AE E AE E a s 35 4 2 Getun Started o E E PR 35 4 3 Calibration Guilde P een aE ea E E E A aiia enii 35 4 4 Client Database Link InstrUCUOhs eere eterne inen nena na Enna e ann aee eaa 35 4 5 NTICEFOSLEHC t re Gude cose r E RE MOT ED E LU C RUE 35 4 6 Technical Manual e E OR REESE AE E OE ait 35 92 HCOME MIST ONs cistorie izes Pens otetot als a i Mdh nost m nA LUE 36 Appendix A HSMM User Documentation 3 ee dee e UM ciated a ee padres 37 Appendix B UBC Report on Dual Phase Mo Steel eese 37 TRP 0040 Final Report vi March 30 2005 LIST OF FIGURES Figure 1 User Interface for HSMM version 4 0 sess ener nnne nennen 2 Figure 2 User Interface for HSMM version 6 2 sess eene een en tene netene eret en nennen 3 Figure 3 Modularity of Software Modules for Easy Modification or Replacement 4 Figure 4 Sample original code without error checking comments or descriptive names 4 Figure 5 Sample Fortran 95 code with error checking comments amp descriptive names 5 Figure 6
54. te the thermal properties based on when phase transformation occurs TRP 0040 Final Report 25 March 30 2005 Grade Edit Selection DOSK teadonly E Save Grades Grade Management Grade Thermal Properties Grade Microstructure Properties heal cise Seecioney 7 ViewPiopety SpeciicHest Vestoe ET usc BISRA Temperature C Specific Heat J Ka C gt Property Chart 200 400 600 800 1000 1200 1400 Temperature C Figure 28 Thermal Property Selection by Phase UBC Method Method 2 BISRA uses curves developed by the British Iron and Steel Research Association see Figure 29 This method will describe the thermal properties based on when phase transformation occurred during development of the curves The advantage of using these curves is that the range of the model can now be expanded to uses outside of the scope of the sample grades of steel for thermo mechanical calculations i e stainless steel Dual Phase TRIP steels TRP 0040 Final Report 26 March 30 2005 Gisde Ear Sectio 00 6 rm x fa Seve Grades Grade Management Grede There Process Grade Mirocnatuss Properties Dhana Gissa yy DISA OE LCS ODAC View Propane Specie Heat zi uec ll BISFA Terosdue C Spechc Hes Kg C Property Chart Figure 29 BISRA Thermal Property Selection BISRA Method 2 4 3 Extended ROT Transformation Model into Coiler In HSMM version 4 0 all transformation was expected to occur
55. the coiler or cooling bed Not only did this improve the efficiency of running the model for the user but also improved the accuracy of the temperature and microstructure calculations by continuously tracking the material s process parameters such as temperature grain size precipitation in austenite retained strain etc through all areas of the mill Three calculations points along the material length were chosen for tracking the headend the middle point and the tailend as shown in Figure 6 Calculation Points Middle Figure 6 Tracking Calculation Points Accurately tracking the timing of the three points through the entire hot mill requires user input of the threading and top speeds during rolling and tables speeds during transfer between stands as well as the stopping distances and delay times for passes at reversing stands An example speed profile between two individual rolling stands is shown in Figure 7 Applying the actual acceleration and deceleration rates when changing speeds improves the timing and temperature calculations With more accurate temperature predictions being calculated and provided to the microstructure calculations more accurate microstructure and mechanical property calculations were also achieved TRP 0040 Final Report 6 March 30 2005 Stand 1 Top Table Speed Stand 2 Rolling Speed Rolling Speed Head Middle Tail Head Middle Tail Out of out of out of into into into Stand 1 Stand 1 Stand 1 St
56. tors that are difficult if not impossible or impractical to include in any thermal model e g the cooling effect of roll cooling water that reaches the strip or the effect of a water spray that remains partially plugged Because these variable factors cannot be modeled other thermal models need to be adjusted with tuning coefficients to compensate for these factors and produce reliable results Separate thermal model tuning coefficients and multipliers were added for the single node and multiple node models as shown if Figures 20 and 21 respectively TRP 0040 Final Report 19 March 30 2005 Common Single Node Multiple Node Mechanical Properties Rarely Modified Mill Areas Tuning Coefficients Radiation Effect Runout Table Tuning Coefficients Water Thermal Conductivity Top Header Calibration Factor Bottom Header Calibration Factor Top Header Water Effect Low Coiling Temperature Coefficient Figure 20 Single Node Thermal Model Tuning Coefficients Common Single Node Mutipte Node Mechanical Properties Rarely Modified Unis Value Mill Areas Tuning Coefficients O o Radiation HTC Factor Conduction HTC Factor to Work Roll Roughing Area Conduction HTC Factor to Work Roll Finishing Area Descale Water HTC Factor Roughing Area Descale Water HTC Factor Finishing Area Interstand Cooling Water HTC Factor Description Wits Vae Runout Table Tuning Coetficients Top Boilin
57. uct with good shape its relative 96 crown can change only so much until the internal stresses either cause buckles down the center of the strip or waves down the edges The amount of allowed crown change has been defined by an upper and lower limit that produces a shape envelope as shown in Figure 14 c e 2 11 C hl h2 where cl entry crown c2 exit crown 1 86 1 86 Edge Wave iE gt Ac gt C Center Buckle 2 12 w w TRP 0040 Final Report 13 March 30 2005 Shape Envelope F5 Edge Wave o o c o c z o i o o 2 z amp O tc FM Stand Center Buckle Edge Wave Strip Shape Figure 14 Shape Envelope and Calculated Curve By adjusting the reductions in the finishing mill and the bending forces if available the material shape can be made flat or at least improved 2 2 7 Additional Mill Equipment Enhancing the HSMM for version 6 2 included expanding the temperature models to simulate some common mill equipment items such as heat covers also known as thermal covers thermal panels table covers etc and cooling beds for plate products Heat Covers Heat covers are modeled by applying an elevated ambient temperature input for the headend and a calculated ambient temperature for the tailend based on the headend temperature that pre heats the covers Both top and bottom and top only heat covers can be modeled Cooling Bed A cooling bed is av
58. y participants Dofasco IPSCO Stelco US Steel Weirton Steel formed the HSMM Enhancement Group to provide input and support to the effort The goals of this project were twofold 1 test and validate the existing HSMM using operating data from the plants and 2 enhance the HSMM as required to improve the results With the release of HSMM version 6 2 the goals of the project have been successfully completed An extensive validation and verification program for the enhanced HSMM was performed using a multitude of samples from the Enhancement Group steel companies Excellent agreement was obtained for tensile strength from a variety of steel chemistries and mill configurations Enhancement features incorporated into versions 6 0 6 1 and now the final version of the HSMM 6 2 that have made it more flexible and practical to use include e Improved user interface e Ability to link all models and track the material through the entire mill e Improved temperature and force modeling e Ability to calibrate the temperature and force models from plant data Ability to view and adjust the microstructure calculation algorithms and coefficients The supporting steel companies have found outstanding value in the HSMM in saving them time and money for a variety of practical applications The HSMM continues to be marketed and sold TRP 0040 Final Report lii March 30 2005 on a global basis as the industry s leading PC based off line model for helping

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