| MONDAY | WEDNESDAY |
Tuesday, May 8
Afternoon Sessions
2 p.m. — Coke Producing/Iron Producing — Coke Quality and Ironmaking - back to top
Room 101
Session Chairs: Robert Donaldson, Dofasco Inc.; Jack Garzella, J.G. Jr. Consulting & Assoc.; Tom Dohnal, Wheeling-Pittsburgh Steel
2 p.m.
Devolatilization and Cracking Behavior of Australian Lumpy Coals at High Temperatures
S. Gupta, University of New South Wales; S. Lee, University of New South Wales; S. Kim, POSCO; B. Kim, University of New South Wales; V. Sahajwalla, University of New South Wales
Five Australian lumpy coals were pyrolyzed in a TGA reactor and a visualization furnace to investigate the effect of coal properties, particularly particle size and temperature. Total volatile yield was found to be the same, irrespective of particle size and temperature, while kinetics was shown to be influenced by particle size and volatile matter. Crack initiation of lumpy coals during pyrolysis was related to coal properties including initial porosity, volatile matter, ash content, carbon structure and swelling behavior. Improved understanding of pyrolysis behavior of lumpy coals would lead to a better understanding of coal performance in new ironmaking technologies such as COREX.
3 p.m.
Use of Higher Levels of Canadian Coal in Blends With a High Percentage of Semi-soft Coals, Part 2: Industrial-scale Trial
K. Kato, Nippon Steel Corp.; A. Dobashi, Nippon Steel Chemical Co. Ltd.; R. Leeder, Elk Valley Coal Corp.; T. Arima, Nippon Steel Corp.; K. Ikeda, Nippon Steel Corp.; Y. Suzuki, Nippon Steel Corp.; C. Kolijn, Elk Valley Coal Corp.
Based on lab and pilot-scale coking test results in Part 1, a two-month industrial trial was conducted at the NSC Kimitsu works to investigate the use of higher levels (e.g., up to 40 percent) of Canadian coking coal using blends with a high level (e.g., 30 percent) of semisoft coal. During the trial, the semisoft coal content in the coking blend level was kept at 30 percent, and the level of Elk Valley coal was successfully increased from 15 to 40 percent. Coke quality was maintained. The coke plant operated very smoothly during the whole test period, and there were no effects of carbon deposition or coking pressure over the range (15–40 percent) of Canadian coking coal used. The coke produced fed one blast furnace whose performance was consistent throughout the two-month trial. Details of the program will be discussed.
3:30 p.m.
Effect of Iron-bearing Minerals on the Gasification Behavior of Coke
B. Gupta, University of New South Wales; S. Gupta, University of New South Wales; V. Sahajwalla, University of New South Wales; R. Sakurovs, CSIRO; D. French, CSIRO; M. Grigore, University of New South Wales
The gasification behavior of cokes made from coals containing various iron minerals was investigated at a range of temperatures. Coke properties — particularly the proportion of iron-bearing phases such as metallic, sulfides and oxides — were quantified to show their influence on coke gasification. The study further showed that all the iron phases do not necessarily influence the coke reactivity. The implications of different iron minerals such as pyrite and siderite on coke reactivity are discussed. Improved understanding of iron phases in coal and their transformations during coking would allow increased control over coke reactivity for conventional and emerging blast furnace operations.
4 p.m.
Chemical Interpretation of Tuyere Drill Cores From the Ruukki Blast Furnaces, Coke and Fines
R. Kanniala, Rautaruukki Oyj; O. Kerkkonen, Rautaruukki Oyj
Ruukki manufactures iron at two medium-sized blast furnaces. Oil injection is used at both furnaces. Core drilling toward the blast furnace center through a tuyere has been used to obtain information regarding coke degradation below the shaft, to contribute to feed coke optimization. Currently, data are available for 19 drillings from blast furnace No. 1 and 19 from blast furnace No. 2. This paper deals with how Ruukki interprets tuyere drill cores based on the chemical and mineralogical differences in coke and fines. Focus is on maximum formation of fines, differences at same feed coke and maximum reducing agent consumption.
2 p.m. — Iron Producing — Blast Furnace Equipment and Facilities- back to top
Room 102
Session Chairs: Robert Steiger, Didier-M&P Engineering Inc.; David Walnoha, Paul Wurth Inc.; Richard Mokros, WCI Steel Inc.
2 p.m.
The Implementation of UltraLife Copper Casting Technology in the Blast Furnace
L. Valentas, Berry Metal Co.; A. MacRae, MacRae Technologies Inc.; S. Slaven, Falcon Foundry; G. Slaven, Falcon Foundry
Cast copper water-cooled staves and tuyeres with a novel copper alloy pipe are now operating in high-heat-load areas in many blast furnaces, smelting furnaces and electric arc furnaces. The patented combination of cast copper to copper alloy pipe coil has demonstrated a superior design versus other water-cooled copper technologies, to improve heat transfer and to extend the service life of the product. The new coolers will be described, as well as the fundamental advantages of the copper alloy, as compared to existing designs.
2:30 p.m.
Operation and Key Design Features of the Siemens VAI Gimbal Top Charging System
P. Whitfield, Siemens VA
3 p.m.
Improvement of Taphole Performance by Using a Hydraulic Taphole Drill
M. Oliveira, CST Arcelor Brasil; J. Pereira, CST Arcelor Brasil; R. da Cruz, CST Arcelor Brasil; L. Andrade, CST Arcelor Brasil; C. Ferreira, CST Arcelor Brasil
The work of the taphole opening is one of the most important operations of the blast furnace process, as it is responsible for the stability of the blast furnace. Other important elements are the choice of appropriate clay masses, drill bits and the optimum opening strategy. This paper shows the development, the technology and the results reached in CST Arcelor’s No. 2 blast furnace after changing the taphole drill machines from pneumatic to hydraulic. This represents an important investment to improve the operational results — increase the stability of the process, lower operational costs and increase safety conditions — in order to help the No. 2 BF reach a long campaign life with a high productivity.
3:30 p.m.
Contemporary Blast Furnace Top Charging Practices
S. Koehler, Paul Wurth SA; G. Thillen, Paul Wurth SA; V. Dobroskok, Moscow State Institute of Steel and Alloys; J. Buchwalder, Arcelor Mittal; R. Goffin, Paul Wurth SA
Today’s economic conditions and environmental constraints lead to specifications of raw materials that many blast furnace operators would have rejected in the past. These current circumstances, as well as the need for higher blast furnace productivity, lead to new challenges and solutions related to blast furnace top charging. This paper discusses new approaches in top charging philosophy, the use of charging models as a modern tool for predicting and confirming blast furnace behavior, and the particular success in operating blast furnace 5A at Arcelor Eisenhüttenstadt. Together with the latest improvements of the Bell-less TopTM charging system, these subjects open the way to matching today’s requirements to achieve the best ironmaking performance in a more complex and demanding operating environment.
4 p.m.
The Advantages and Disadvantages of Incorporating a Fourth Stove Within an Existing Blast Furnace Stove System
C. Colling, Siemens VAI; P. Martin, Siemens VAI
There is a growing trend among ironmakers, particularly those operating plants built in the 1970s or before, to add a fourth stove to the blast furnace hot blast system. The reasons for adding a further stove to the system are usually to provide increased security of operation and to provide more operational flexibility. However, if the fourth stove is correctly specified at the time of ordering and a modern control system is incorporated, significant increases in blast duty can be achieved. This paper explores the advantages and disadvantages of incorporating a fourth stove, both technically and financially.
4:30 p.m.
High-temperature Shaftless Hot Air Stoves With Long Service Life for Blast Furnaces
L. Kalugin, Kalugin JSC
A new design has been developed, introducing the shaftless hot air stove, which eliminates the need for a conventional combustion chamber. With the new design, a precombustion chamber is located at the top of the dome. This arrangement eliminates the potential for “short-circuiting” between the combustion chamber and checker chamber. Efficient gas burning is achieved, and pulsations at the entrance to the checker chamber are nonexistent in all operating modes. The shaftless hot air stove offers a refractory weight reduction of 30–50 percent in comparison to internal combustion chamber stoves of comparable performance. Hot blast temperatures of 1,400°C with service life estimated at 30 years can be realized. Sixty-eight shaftless hot air stoves are in operation in Russia, China and Ukraine, and 33 more are in the process of being designed and constructed. Some of these stoves are being furnished for blast furnaces with a volume up to 5,500 m3. Advantages and design features will be discussed.
2 p.m. — Iron Producing — Raceway Phenomena - back to top
Room 103
Session Chairs: Thomas Kuhl, Dofasco Inc.; James O’Day, Republic Engineered Products; O. Fortini, Alcoa Technical Center
2. p.m.
Experimental Probing of Temperatures in Blast Furnace Tuyeres
C. Rabold, U. S. Steel Corp.; E. Serrano, U. S. Steel Corp.
In pursuit of a better understanding of the profiles of gas temperature developing inside a blast furnace tuyere, two thermocouples were installed in the copper body of a tuyere. Measurements of temperature in the thermocouples were combined with a simple heat transfer model, which allowed the evaluation of two modes of injection during furnace operation. The results showed that significant combustion of tuyere injectants may occur along the axis of the tuyere, before the gas enters the raceway. These results are expected to help in determining the total pressure drop in the furnace when operating with different tuyere injectants.
2:30 p.m.
Computer Modeling of Blast Furnace Raceway Formation Kinetics
M. Gu, Purdue University Calumet; C. Zhou, Purdue University Calumet; Y. Zhao, U. S. Steel Corp.; N. Selvarasu, Purdue University Calumet
The blast furnace raceway shape, size and position are determined by the kinetic force of the blast from tuyeres, as well as the combustion process inside the raceway. This paper focuses on the effect of the kinetic force on raceway formation. Using Computational Fluid Dynamics (CFD) modeling, this work investigated the effect of tuyere geometry, wind rate, coke porosity on the raceway formation. The effect of combustion on raceway formation will be presented in another paper.
3:30 p.m.
Numerical Simulation of Combustion Phenomena in the Raceway Under Different Injection Conditions
J. Wikstrom, MEFOS; P. Hellberg, MEFOS; D. Sheng, MEFOS
Due to economic and environmental considerations, the main focus in blast furnace improvement has been directed for several years at the substitution of coke with coal. A fundamental mathematical model has been developed to study the coal combustion phenomena in the raceway by the coupled solution of the flow field and the combustion reactions. Different injection situations have been modeled, such as coal types, oxygen contents in the blast, lance construction and positions. The modeling technique is presented and discussed along with the implied results. The flow pattern and temperature distribution show good agreement with the experimental results and previous studies. Optimal coal combustion conditions are proposed based on the parameter studies, and some future developments are also discussed.
4 p.m.
The Control of Blast Furnace Operations Through a Tuyere Practice Based on RAFT or HTR
W. Lu, McMaster University, J. D’Alessio, Stelco Hamilton Steel, O. Lingiardi, Ternium Siderar S.A., H. Gou, Dofasco Inc., D. Vanmarrum, Algoma Steel Inc.
Inan iron blast furnace, the descending rate of solids is essentially determined by the space creation down below by melting and tapping. On the other hand, the properties of the newly formed liquids that affect the state of hearth are determined by the corresponding gas flow, which may be characterized by the total amount of the gas and its composition and temperature. The matching of these counter-current gas and solid flows and their distributions are essential for efficient, stable and safe operations. Until recently, RAFT has been used to control the tuyere practice, i.e., the type of gas to be generated. Based on the fact that iron ores are being heated and reduced simultaneously and based on the softening/melting characteristics of each ore, and consequently the properties of cohesive layers and cohesive zone, a new index, the heat-to-reductants (HTR) ratio is proposed to replace RAFT in tuyere practice.
4:30 p.m.
Numerical Study of Pulverized Coal Injection With Natural Gas Co-injection in a Blast Furnace
N. Macfadyen, Union Gas Ltd.; M. Gu, Purdue University Calumet; N. Selvarasu, Purdue University Calumet; C. Zhou, Purdue University Calumet; W. Walker, Purdue University Calumet; J. D’Alessio, Hamilton Steel
In a blast furnace, natural gas co-injection with pulverized coal is primarily used as an alternative fuel source to coke. It can also provide hydrogen in the bosh gas for iron ore reduction and has potential to significantly improve the coal combustion efficiency. To evaluate these benefits of natural gas co-injection, computational fluid dynamics analysis of different natural gas usage strategies has been conducted. The effect of the addition of pre-ombusted natural gas in the blast air stream has also been studied. This paper will describe the results of detailed distributions of devolatilization, burnout, reducing species, velocity and temperatures within different co-injection conditions.
2 p.m. — Electric Steelmaking — EAF Equipment - back to top
Room 117
Session Chairs: Angelo Manenti, Core Furnace Systems Corp. Ricardo Anawate, Gerdau Ameristeel
2 p.m.
Design, Installation and Operation of the Nucor Auburn Electric Arc Furnace Replacement
The minimill at Nucor Auburn has been in operation since 1975, utilizing a traditional spout-tap arc furnace. Despite continuous improvements in the electric arc furnace operation in both practices and equipment over the years, the basic arc furnace structure (platform, gantry and electrode operating mechanism) remained essentially the same as originally supplied. An ROI analysis that considered energy improvements and lower cost to convert scrap to liquid metal prompted Nucor Steel’s board to approve funds in 2005 for a complete furnace rebuild, with installation to take place in the fall of 2006. The furnace revamp is presented from the initial planning stage through engineering, fabrication, installation, start-up and continuous operation. This paper discusses the specific improvements made to the electric arc furnace, including the underlying concepts for the new design, as well as operating results.
2:30 p.m.
The Electric Arc Furnace of Tenaris Dalmine: From the Application of the New Technologies of Digital Electrode Regulation and Multipoint Injection to the Dynamic Control of the Process
L. Ferro, Tenaris; J. Maiolo, Tenova Goodfellow; F. Memoli, Tenova; P. Guigliano, Tenarisdalmine; P. Galbiati, Tenarisdalmine; C. Giavani, Tenova
The EAF of Tenaris Dalmine, located in northern Italy, is a 20-foot furnace with a tapping capacity of 105 tons of liquid steel. This EAF has been equipped during the last five years with the most innovative technologies for scrap melting and refining, including electrode digital regulation, the multipoint oxygen and carbon injection system, and a complete and modern level 2 automation that supervises the meltshop from the preparation of the scrap buckets until the production of the round bars. This paper describes how all these technologies have been integrated, the correct use of them — in terms of management of the electrical and chemical setpoints in order to get the maximum possible synergy — and the target of dynamic control of the process. This last step is the eventual conclusion of the EAF process development, where real-time analysis of the furnace parameters drove the electric arc furnaces to obtain the best historical performances.
3 p.m.
The New Giant Generation of EAFs
R. Gottardi, Concast AG; S. Miani, Concast Technologies; A. Partyka, Concast AG
Recent projects and new EAF orders indicate the new trend in furnace design: very large electric arc furnaces. Concast, after the first successful installation in 2003 of the 180-ton EAF at Icdas, is confident the same outstanding performance of this EAF can be achieved with the new 300-ton EAF. The equipment installed and the furnace design will follow the “ultrahigh chemical power” EAF indexes. Analysis of the basic engineering parameters and the extrapolation of its performance will be discussed.
3:30 p.m.
A New Era for the Continuous Scrap Charge: The Definitive Success of Consteel® Technology and Its Expansion in Europe From a Productivity and Environmental Perspective
A. Manenti, Core Furnace Systems Corp.; F. Memoli, Tenova
This paper presents the evolution of the Consteel® technology and includes all the new features that were developed on the way to its eventual success as the only real alternative to the conventional electric arc furnace. In the first 10 years the Consteel system was applied mostly in the United States, where it was initially created and engineered. From a technological point of view, the system’s function of scrap preheating responded to the needs of variable cost reduction in the U.S. market. During the subsequent five years, the Consteel system expanded into China. In order to satisfy the requirements of the Chinese market, Consteel was improved on the engineering side, stressing the continuous charge function in order to achieve high productivity increases. Today, Consteel technology is expanding into Europe. In the last few years, three applications have been started up in this region. Increasing Consteel’s productivity, as well as environmental considerations of the technology, are the main keys to success of the projects in the European market.
4 p.m.
Method and Apparatus for Steelmaking in a Sealed Metallurgical Furnace
E. Wuensche, EMPCO Canada Ltd.
This paper presents an economic steelmaking process and apparatus in a sealed metallurgical, preferably electric arc steelmaking furnace, characterized by decisive energy consumption reduction, sizable volume reduction of hot polluting toxic exhaust gases and several other significant improvements, achieved by functional control of the shell “slag door opening.” Because of its multifunctional design, the compound aggregate apparatus becomes an integral part of the furnace shell, made possible by the shell’s extremely simple modification. Achievable benefits include: up to 50 percent reduced cold air infiltration; 15 percent exhaust gas reduction; 30–80 kWh energy savings; productivity increase; uniform melting; improved foamy slag control; shorter tap-to-tap time; reduced FeO in the slag; no slag door burner; no scrap pushing from tunnel; and no ram breast cleaning.
4:30 p.m.
Meltshop Materials Handling Systems — Innovations and Applications
M. Olean, Core Furnace Systems Corp.; A. Manenti, Core Furnace Systems Corp.; J. Simmons, Core Furnace Systems Corp.
A common misconception of ferroalloy, flux and metallics material handling systems has been that they are “marginal” meltshop process equipment. However, in the economy of a meltshop, the impact of a material handling system in terms of reliability, efficiency and delivery of materials to the other pieces of steelmaking process equipment can greatly influence steel production costs. In an era of high-priced raw materials, the meltshop material handling system is no longer marginal, but an important component of an efficient meltshop. This paper will analyze the latest designs and improvements for meltshop material handling systems while identifying possible savings, and recent applications will be discussed.
2 p.m. — Specialty Steelmaking — Refining and Casting of Stainless Steels - back to top
Room 113
Session Chairs: Allen Chan, Praxair Inc.; Mark Suer, Special Metals Corp.
2 p.m.
Upgrading Stainless Steel Slags With Borates
M. Greenhill-Hooper, Rio Tinto Minerals; D. Schubert, Rio Tinto Minerals; T. Wilhelm, Rio Tinto Minerals
As stainless steel slag cools, it expands, forming a dusty calcium silicate, which is often termed “falling slag.” The transformation of the CaO/SiO2 ratio (a'C2S to g'C2S) results in a powder forming. This falling slag can be prevented by the addition of borate, B2O3, to the molten slag, either in the slag pot or as it is poured off. Upon addition of B2O3, the bC2S polymorph forms. Since bC2S has a similar density to a'C2S, the result is a stable, rock-like material forming. A review of the slag chemistry and treatment techniques, plus the commercialized product Vitroc®, will be discussed.
2:30 p.m.
Latest Design Aspects of the AOD Steelmaking Converter
S. Dimitrov, Siemens VAI; G. Staudinger, Siemens VAI
Since the year 2000, an increased demand for stainless steel production has been observed worldwide. In the 1990s, a typical stainless steel plant had an annual capacity of 0.5 million tons/year based on an 80- to 100-ton heat size. In the year 2000, the nominal heat size increased to 120–150 tons, achieving 0.7–0.8 million tons/year. Recently, because of further increased demand — especially in China — and the necessity for reduced production costs, the capacity of stainless steelmaking plants was increased up to 1 million ton/year based on a 180-ton heat size. SIEMENS VAI, a leading supplier for steelmaking and particularly for the stainless steelmaking industry, introduced several improvements for equipment as well as process technology and was contracted for major projects. This paper shows some new design features and technological results of a modern, state-of-the-art AOD converter.
3 p.m.
Kinetic Model of Nitrogen During the AOD Refining Process of Stainless Steel
Z. Chen, Baoshan Iron & Steel Co. Ltd.
According to the thermodynamics and kinetics of nitrogen absorption and nitrogen removal, a mathematical model for nitrogen change during the AOD refining process of stainless steel has been developed. It was integrated with the mathematical model of the rates of C, Cr, Mn, Si, O, N and temperature in melt during the oxidation refining and reduction refining. It was also integrated with the balance relations of heat and mass. The predictions of the melt compositions and temperature based on the model were compared with the measured data obtained for a 120-ton AOD refining operation of stainless steel at Baosteel. The predictions and measured data showed good agreement. The influence of a blowing model on nitrogen change in the melt is also discussed.
3:30 p.m.
Characterization of Steelmaking Production Methods by Extreme Values Statistics and High-frequency Ultrasonic Testing
G. Romanelli, Acciaierie Venete Spa; S. Buoro, Acciaierie Venete Spa
In this paper, two different material investigation techniques — extreme values statistics and high-frequency ultrasonic yesting analysis — are applied to semifinished steel products for characterizing the micro- and macroinclusional content of specialty steels for the automotive industry. The results of the investigation have shown the feasibility of the two above-mentioned methods to determine the process capability of different steelmaking production routes in terms of inclusional content. The material properties analyzed have been cross-checked with the mechanical properties, including fatigue testing, to optimize the steelmaking manufacturing processes of high-cleanliness steel grades at the Acciaierie Venete plant in Padua (Italy).
4 p.m.
Continuous Casting Technologies of Stainless Steel at POSCO Stainless Steelmaking Plant
J. Kim, POSCO; S. Kim, POSCO; J. Kim, POSCO; J. Choi, POSCO
The Pohang Works of POSCO began producing stainless steel by continuous casting in March 1989. Many continuous casting technologies have since been developed to improve the operation and quality of slabs. Depressions and deep oscillation marks on the surface of austenitic stainless steel slabs can be reduced by the stable mold level, optimum SEN submergence depth and proper application of mold powder. Improvements in ridging of ferritic stainless steel have occurred due to increased equiaxed crystal in slabs, which were obtained by the optimum-stirring pattern of EMS. Stainless steel of almost any grade can be produced from continuously cast slabs.
4:30 p.m.
New Strong Strand Stirrer Boosting Quality of Ferritic Stainless Steel
N. Jacobson, ABB Process Automation; H. Hackl, ABB Process Automation; J. Galpin, Ugine & ALZ Carinox S.A.; V. Lambert, Ugine & ALZ Carinox S.A.
The demands on a large equiaxed ratio are today very high for ferritic stainless steel. Therefore, a new stronger strand stirrer has been developed and the first installation was at Arcelor’s Carinox plant in Chatelet, Belgium. The stirrer is of the box-type solution, installed behind stainless steel rolls in the machine. Results are very good, and approximately 55 percent equiaxed ratio is obtained. In order to optimize the stirring, a three-dimensional simulation model has been developed, simulating flow and temperature fields for different casting conditions, thus assuring good stirring without disturbing the meniscus.
2 p.m. — Oxygen Steelmaking — BOF Charge Models and Endpoint Control - back to top
Room 105
Session Chairs: Michael Speranza, B.E. Speranza Inc.; Florian Kongoli, Flogen Technologies Inc.; Champion Chigwedu, Mittal Steel USA
2 p.m.
Getting More Steel Out of Less Hot Metal at Ternium Siderar
W. Balante, Ternium Siderar; A. Gomez, Ternium Siderar; R. Donayo, Ternium Siderar; J. Perez, Ternium Siderar; R. Ares, Ternium Siderar
Ternium Siderar, located in San Nicolas, Argentina, experienced a period of single blast furnace operation in 2006 due to the unavailability of one blast furnace and the relining of another. In order to take advantage of the excess steelmaking capacity, processes were adjusted to reduce the amount of hot metal needed for the production of a ton of steel. This paper describes the principal changes in the process, such as the increase in the manganese content of hot metal to avoid manganese addition in the converter, the heating of scrap, coke additions, the increase of pig iron, the use of SiC or FeSi during blowing in large quantity, the development of new postcombustion lance tips, new lance profiles,and temperature decrease at end of blow. All of this permitted Siderar to increase slab production with respect to it standard process.
2:30 p.m.
Advantageous Numerical Simulation of the Converter Blowing Process
U. Falkenreck, SMS Demag AG; J. Kempken, SMS Demag AG; W. Emling, SMS Demag Inc.; H. Odenthal, SMS Demag AG; J. Schluter, SMS Demag AG
Although the combined blowing process in BOF converters is state-of-the-art, it still offers possibilities for improving steel quality and plant productivity. For instance, the design of the top lance; the number, dimension and arrangement of the bottom tuyeres; as well as the blowing rates, are important for the phase interactions and chemical reactions. To illustrate the influence of these parameters on the BOF process, a novel computational fluid dynamics model for the three-dimensional, time-dependent and nonisothermal multiphase flow in converters has been developed. The model is based on the Reynolds averaged Navier-Stokes (RANS) equations and the standard k-e turbulence model. It considers several fluid dynamic aspects, such as the expansion of the supersonic oxygen jets, the formation of the melt cavities, the interaction of the melt-slag-gas phases, the gas bubble–induced motion of the melt, and the heat transfer inside the refractory lining. Furthermore, the model predicts splashing effects, lance skulling and mixing times.
3 p.m.
Evaluating Postcombustion Capabilities at the BOF Shop
C. Chigwedu, Arcelor-Mittal Steel USA
In the late ’70s and early ’80s, the realization that much more energy could be exploited by forcing the final step of carbon oxidation from CO to CO2 promised the possibility of melting more scrap than usual for the BOF process. However, practice soon revealed that the energy was there, but that the practical challenge resided in directing it to the scrap or bath instead of the converter mouth, the cone and/or the blow lance. This work set out to establish how much postcombustion happens with and without the PC lance in the BOF process. It highlights the difference in practice between North American and European steelmakers.
3:30 p.m.
Basic Slag Generation in Steelmaking Processes – with Special Reference to the BOF
I. Prendergast, AK Steel
High-temperature metallurgical processes are generally batch (BOF, EAF, AOD, TBRC, etc.) or semicontinuous (smelters, etc.). In these processes, the conditions and reactants are closely controlled and lead to a vessel equilibrium condition at the desired end of the batch process. This review discusses the BOF process, and in particular the generation of a basic oxide slag from a combination of fixed and variable additions. The slag reaches equilibrium at the end of the process, whose value can be described using optical basicity. This paper describes the underlying theory, assumptions and results from several BOF operations.
4 p.m.
The Methods, Aims and Practices (MAP) of BOF Endpoint Control
B. Chukwulebe, Mittal Steel USA; K. Robertson, Mittal Steel USA; J. Grattan, Mittal Steel
BOF shop productivity, cost and steel quality performance depend largely on efficient control of endpoint temperatures and chemistries. In this paper, the different methods of endpoint control are compared. The role of various operating practices — including blowing lance practices, and the use of various coolants and fuels in controlling endpoint temperatures and chemistries — is discussed. Theoretical analysis is performed to highlight the likely effects of turndown performance on key parameters such as yield, process time and Al consumption. The importance of shop coordination and setting proper endpoint performance targets is emphasized to reduce the snowball effect of negative consequences downstream in the furnace.
2 p.m. — Ladle and Secondary Refining — Ladle Refractories - back to top
Room 106
Session Chairs: Richard Hrechko, CMC Steel; Monty Parker, Nucor Steel Corp.; Jimmy Barrett, Mittal Steel USA
2 p.m.
High-temperature Performance of Al2O3-SiO2-SiC-C Refractory while using Al and BN Additives
V. Sahajwalla, University of New South Wales; L. Hong, Shinagawa Refractories Australasia Pty. Ltd.
High temperature experiments were carried out to investigate the performance of Al2O3-SiO2-SiC-C refractory against slag penetration. Slag composition was 45.4%SiO2, 36.6%CaO, 15.9%Al2O3 and balanced by MgO, P2O5 and S. Temperature was 1823 K. Al and BN were used as additives to improve slag penetration resistance of the refractory. Infrared (IR), scanning electron microscopy energy dispersive spectrometer (SEM-EDS) and x-ray diffraction (XRD) results showed that Al was very effective in improving slag penetration resistance of the refractory, while BN made refractory worse. A used refractory sample from industry was analyzed using x-ray and SEM-EDS to compare properties of an actual industry process with a high-temperature experiment in the laboratory, and good agreement was found.
3:30 p.m.
Evaluation and Suitability of MgO-C Refractory for the RH Degasser Lower Vessel
S. Chaterjee, Orind Refractories Ltd.; S. Mukhopadhyay, Orind Refractories Ltd.; R. Mishra, Orind Refractories Ltd.; S. Kumar, Orind Refractories Ltd.; Y. Tripathi, Orind Refractories Ltd.
Typical RH degasser lower-vessel bricks should have excellent thermal spalling resistance and corrosion resistance against the RH slag. Conventionally direct-bonded magnesia-chrome brick has long been the only choice for the RH degasser lower vessel. Because an integral component of these bricks is chrome oxide, they create a pollution problem with hexavalent chrome during application, which is not eco-firendly. A great deal of research has been conducted to develop suitable MgO-C bricks with no chrome, because such bricks have excellent spalling resistance due to the presence of graphite. The slag corrosion resistance against the RH slag, however, is not that good compared to mag-chrome brick. Moreover, MgO-C brick has the disadvantages of decarburization at high temperature and under high vacuum, carbon pickup and oxidation problems. Therefore, MgO-C bricks can be applied in this area only if the associated problems can be solved. This paper describes the development of low-carbon MgO-C for the RH degasser lower vessel to counter these problems with higher oxidation resistance.
4:30 p.m.
Improvement in Performance of Magnesia-carbon Bricks Through Addition of Magnesia-aluminate Spinel in a 130-ton Steel Ladle at Bhilai Steel Plant
A. Bhattacharyya, Steel Authority of India Ltd.; D. Chakraborti, Steel Authority of India Ltd.
Magnesia-aluminate spinels have been found to be an excellent additive in the formulation of magnesia-carbon refractory for steel ladles. For 130-ton steel ladles routed through LD-LF-RH/VAD-CC for the production of rail steel, thick plate of boiler grade, API plates and heavy structurals at Bhilai Steel Plant, part of the microfines of MgO grains were replaced with reactive alumina-rich spinel in formulating MgO-C bricks for the sidewall of the metal zone and stoichiometric sintered spinel for the slag zone. The presence of spinels improved the performance markedly both in the metal zone and the slag zone. The purpose of adding alumina-rich spinels in the metal zone was to have continuous spinel formation in the hot face due to the reaction of the alumina with MgO fines of periclase grains incorporating continuous and controlled expansion of the MgO-C bricks, making the bricks’ joints tight and inhibiting metal penetration. Addition of stoichiometric spinel in the slag zone bricks facilitates trapping of oxides of iron and manganese from slag, making the slag less corrosive. This paper provides details of formulation, and improvement in properties including microstructure and trial performance.
2 p.m. — Continuous Casting — Caster Configurations and Practices II - back to top
Room 116
Session Chairs: Jörg Peter, Cascade Steel Rolling Mills Inc.; David Beck, ChemTreat Inc.
2 p.m.
Up-to-date Measurement Devices for Continuous Casters
C. Furst, Voest-Alpine Stahl GmbH; O. Lang, Vatron; R. Sandner, Voest-Alpine Stahl GmbH
Continuous casting machines have to be adjusted properly to produce a high output with good quality. Proper adjustment begins at the mold, where the taper and width of the mold has to be checked, as well as the oscillation. During casting, a mold monitoring system shows the thermal and oscillation condition of the mold, gives detailed analysis of the mold level and its surface, and prevents breakouts. For strand guidance, it is necessary to measure roll gap, roll rotation and segment alignment. Spray water for secondary cooling can also be checked.
2:30 p.m.
Caster Steel Yield Improvement by Enhanced Ladle Bottom Design
J. Richaud, Advent Process Engineering Inc.; J. Dorricott, Advent Process Engineering Inc.; L. Heaslip, Advent Process Engineering Inc.
To improve ladle yield, an understanding of the fluid flow phenomena (including vortex formation and steel bath surface collapse) occurring during the final stages of ladle draining is necessary. In this paper, both computational fluid dynamics (CFD) and physical (water) modeling are used to improve understanding of the draining phenomena that lead to early slag entrainment in the steel flow leaving a ladle. It was found that, as ladle draining proceeds, three phenomena typically occur: early vortexing (low-strength intermittent vortices); full vortexing (a slag-entraining funnel); and surface collapse (occurring when the pressure in the floating slag above the ladle outlet exceeds the pressure in the steel flow, causing a slag outflow from the ladle which overwhelms the steel flow). It was concluded that CFD analysis can be used to predict ladle draining performance. Plant test results with enhanced ladle bottom geometries (ELBY) indicate that significant yield savings can be achieved.
3 p.m.
Fluid Flow Effect on Inclusion Removal in a Tundish With a Swirling Ladle Shroud
R. Morales, Instituto Politecnico Nacional; J. Ramos-Banderas, Instituto Technologico de Morelia; G. Solorio-Diaz, Universidad Michoacana; J. Barreto, Instituto Technologico de Morelia
Nonmetallic inclusion removal from liquid steel in the tundish is studied using a multi-phase flow mathematical model. The removal efficiency is studied as a funtion of a turbulent flow control device, known as a swirling ladle shroud. This device is capable of decreasing the impact velocity on the tundish bottom, and reduces turbulence near the entry jet volume. This achivement is due to a swirling jet that promotes recirculatory flows in the horizontal planes of the tundish. In this study, an analysis of particle removal is carried out, emulating alumina inclusions of sizes ranging from 1 to 160 microns, and verifying the removal efficiency of these devices. The final aim is to avoid the employment of furniture inside the tundish and at the same time to improve the flow conditions and the steel cleanliness in the tundish.
4 p.m.
Tundish Sequence Increase Through the Reduction of Alumina Clogging Occurences
M. Barcellos, Arcelor Mittal - CST; Z. Nascimento, Magnesita S.A.; M. Gallo, MG Servicos Tecnicos
Alumina clogging has been an ongoing issue and a limiting factor for productivity gains and quality assurance. Once its occurrence is minimized, a great increase in yield and production steadiness can be achieved. Also, as a result of new materials application, refractory design and improved assembly procedures, it is possible to measure the impact of such a project on the slivers index of the final product. After fully implemented, it became quite clear that all these benefits were a reflection of the sequence increase and mold level constancy during casting, obtained by the reduction of clogging occurrences.
2 p.m. — Continuous Casting — Secondary Cooling and Strand Containment - back to top
Room 111
Session Chairs: Stephen Swoope, Delavan Spray Technologies; James Raies, Dover Hydraulics Inc.
2 p.m.
Three-dimensional Dynamic Secondary Cooling With Stepless Spray Width Adjustment
K. Hauser, Siemens VAI; H. Wahl, Siemens VAI; K. Morwald, Siemens VAI
VAI developed a three-dimensional spray package for stepless (continuous) spray width adjustment for secondary cooling of slab casters. DynaJet air-mist shaft nozzles are fixed on height-adjustable water and air distributors. These are connected to hydraulic cylinders, which perform the height adjustment. The setpoints for the nozzle adjustment are directly derived from the actual casting width. The spray water density (DYNACS input) depends on the actual water flowrates and the spray area (standoff distance of the nozzles). Thus, the control of secondary cooling is increased.
2:30 p.m.
Design and Implementation of a Real-time Spray Cooling Control System for Continuous Casting of Thin Steel Slabs
B. Thomas, University of Illinois at Urbana-Champaign; B. Petrus, University of Illinois at Urbana-Champaign; K. Zheng, Mittal Steel USA; J. Bentsman, University of Illinois at Urbana-Champaign
Maintaining the shell surface temperature profile under transient conditions by spray water cooling in continuous casting of steel is important to minimize surface cracks. For this purpose, a real-time spray-cooling control system is being implemented in a commercial caster that includes (1) a software sensor for accurate prediction of shell surface temperature, (2) control algorithm and data checking subroutines for robust temperature control, (3) TCP/IP server and client programs for communicating between these two software components and the caster, and (4) a real-time monitor to display the predicted shell surface temperature profiles, water flowrates and other important operating data. Simulation results demonstrate that the new control system achieves better temperature control performance than conventional systems.
3 p.m.
Modification of a 5-strand Bloom Caster for Implementation of Siemens VAI DynaGap Soft Reduction Technology
K. Hauser, Siemens VAI Metals Technologies GmbH & Co.; U. Zanelli, Siemens VAI Metals Technologies GmbH & Co.; T. Huber, Siemens VAI Metals Technologies GmbH & Co.
The increasing demands of the end-users of the products force the development of technological packages, such as the proven Siemens VAI technology for dynamic soft reduction. The advanced bloom DynaGap soft reduction technology from Siemens VAI enables clients to improve internal bloom quality (segregation and porosity).
3:30 p.m.
The Fluid Dynamics of Air Mist Used for the Secondary Cooling of Thin Slabs
I. Hernandez, CINVETAV; A. Castillejos, CINVETAV; F. Acosta, CINVETAV
The heat extraction from continuously cast thin slabs is intimately related to the fluid flow behavior of air-mist jets. To investigate this aspect, the fluid flow field of air and the velocities and trajectories of water drops have been computed by solving the turbulent Navier-Stokes equation for the air coupled to the motion equation for water drops in three dimensions and steady state. The results of these calculations have been validated by comparing the computed drop velocities and the air and air-mist impact pressure fields with corresponding laboratory measurements, obtaining good agreement. Thus, parametric computations were carried out to investigate the effect of increasing the air-to-water ratio on the impact pressure distribution of air-mist jets hitting a flat surface placed perpendicular to it. These fluid flow calculations are the foundation of an air-mist heat extraction model that is being developed.
4 p.m.
Dynamic Soft Reduction of Continuously Cast Slabs
D. Humes, SMS Demag Inc.; J. Laughlin, SMS Demag Inc.; B. Kozak, SMS Demag Inc.; M. Korzi, SMS Demag Inc.
The application of soft reduction on continuously cast slabs is beneficial in mitigating centerline segregation caused by the presence of elements in certain steel grades. This paper will explain the soft reduction process and the application of automation, process technology and secondary cooling influences on the process. This paper will also introduce possible methods for reducing centerline conditions on existing machines. The primary revamp undertaken to overcome this quality problem is to replace the lower portion of the caster containment zone. Another possibility is to introduce proper gap control technology on existing equipment, which is possible on machines with the proper roller apron geometry. Comparative results will be shown to validate the author’s findings on the subject.
4:30 p.m.
Optimization of Slab Centerline Quality Using Dynamic Soft Reduction
D. Mojumdar, Essar Steel Ltd.; B. Kozak, SMS Demag Inc.; P. Chaudhari, Essar Steel Ltd.;
Essar Steel’s No. 3 slab caster was commissioned in the first week of May 2006 for the casting of low-carbon, high-carbon, peritectic, microalloy and high-silicon grades in 220-mm and 260-mm thicknesses, with machine design, process technology and commissioning provided by SMS Demag. The operating and design capabilities of the hydraulic segment adjustment (HSA) system to provide for dynamic soft reduction will be presented, showing the greatly improved centerline condition achieved and the tuning criteria used, resulting in optimum centerline quality.
2 p.m. — Sheet Rolling/Roll Technology — Rolls and Roll Technology - back to top
Wabash Room 2
Session Chairs: Stuart Critchley; Jerry Bunnell, Mittal Steel USA; Paul Heckman, Quality Rolls/Superior Forge
2 p.m.
Measured Residual Stresses in Large Steel Rolling Components
D. Smith, University of Bristol; F. Hosseinzadeh, University of Bristol; C. Truman, University of Bristol
The main focus of this research is to determine methods for improving product quality, production and costs in the rolling process through measurement of residual stress. Component optimization cannot be achieved without the knowledge of the initial (or residual) stress state in the components. Residual stresses combined with applied stresses are, therefore, important ingredients in determining the reliability and life of the rolling components. This paper demonstrates the novel application of a residual stress measurement method called the deep hole drilling (DHD) technique. This method was applied to obtain through-thickness profiles of residual stresses in several rolling mill components. For example, the application of DHD to a 850-mm-diameter roll, consisting of a spheriodal graphite sleeve that had been shrunk to fit a steel shaft, is described. Stress profiles were obtained to depths up to about 400 mm. The results from this roll, together with other roll sleeves, reveal that not only the manufacturing processes but also the operating conditions and material properties greatly influence the distribution of the residual stresses through the components.
2:30 p.m.
Automatic Inspection of Surface Quality in Modern Roll Grinding Machines
D. Schmidt, Waldrich Siegen GmbH & Co.; K. Adamek, Waldrich Siegen GmbH & Co.; S. Weidmann, Waldrich Siegen GmbH & Co.; P. Vinke, Waldrich Siegen GmbH & Co.; M. Smith, Waldrich Siegen GmbH & Co.
Complex camera systems for inspecting the surfaces of rolled strips are increasingly becoming a standard feature in modern hot and cold rolling mills. But such systems can detect defects only on the end product. It would make more sense to inspect the components that ultimately cause such defects before those components are put into use in the mill, to ensure that they are of perfect quality. An automatic roll surface inspection system (RSIS) has been developed that inspects the rolls in the mainly unmanned roll grinding machines to determine whether the surface quality is acceptable.
3 p.m.
Metallurgical Assessment of Two HSS Roll Grades for Hot Strip Mills
J. Breyer, Marichal Ketin Group; J. Lecomte-Beckers, Universitie de Liege; J. Tchoufang Tchundjang, Universitie de Liege
Aurora and Kosmos grades are HSS alloys used for the manufacturing of rolling mill work rolls for early finishing stands of hot strip mills. Both alloys were metallurgically assessed using electron microscopy, x-ray analysis on carbides and differential thermal analysis. These methods allow a better understanding of the behavior of the studied alloys during solidification and cooling. Some mechanical tests were also performed. A connection between the laboratory results and the performance in operation of both grades is described. The strong metallurgical differences — especially as concern the nature and amount of carbides — lead to the good behavior of Aurora in service.
3:30 p.m.
Hot Band Profile Irregularities Related to Thermal Contour of Work Rolls
E. Nikitenko, U. S. Steel Corp.
The causes of the irregularities of the hot rolled strip profile, such as the buildups on both edges of the strip or a one-side edge buildup accompanied by the wedge condition, have been investigated. Through simulations of the thermal conditions of the work rolls in the finishing stands of the hot strip mill, it was established that the particular pattern of the roll cooling and the strip deviation from the mill center line were the root causes of the hot band profile irregularities. Experimental data proves the findings.
4 p.m.
Nonwoven Rolls for Fluid and Strip Control: Understanding the Fundamental Function, Differences, Strengths and Weaknesses of Nonwoven Fabric Rolls Using Practical Experiences
E. Almquist, Star Tool & Die Works
Innovative steelmakers depend on correctly applying unique technologies to stay competitive. Nonwoven process rolls are a unique technology that has delighted steelmakers who have applied them correctly, and they have frustrated those who have misapplied them. This presentation will explain the fundamentals, strengths and weaknesses of nonwoven process rolls. The presentation’s goal is to provide technical facts of this technology and a common understanding of the reality of nonwoven rolls. To make the discussion more practical and tangible, case studies will be posted and explained using a nonpromotional format.
4:30 p.m.
Roll Perfornace in the Hot Strip Mill using Proven Welding Technology and Specially Developed Welding Materials to Reduce Hot Strip Mill Operational Costs and Maximize Productivity
J. Morris, Corewire Ltd.; P. Collins, Corewire Ltd.; D. Le Jeune, Corewire Ltd.
Weld surfacing of selected steel mill rolls should be considered as a surface engineering design tool that can be used to apply a surface with enhanced corrosion, wear and mechanical properties on an existing used roll or a more cost-effective substrate. The full benefits of the technology of roll welding can be realized only if the wire manufacture and the welding process are fully understood and carefully controlled. The successful application of this technology improves roll service performance, minimizes unplanned plant downtime, and hence drives down maintenance costs while maximizing plant utilization and profitability.
2 p.m. — Plate Rolling — Plate Rolling - back to top
Room 110
Session Chairs: Drew Poshard, IPSCO; Richard Smith, Mittal Steel USA; Charles Bender, NSK Corp.
2:30 p.m.
Implementation of a Supply Chain Optimization System at a Plate Mill Producer
P. Knoop, Advanced Information Systems
A major plate mill producer in Belgium produces quality steel plates for a wide variety of applications for customers from all continents. The production environment includes a plate mill, a number of shearing and flame cutting lines, as well as finishing processes such as heat treatment and painting. Slabs are purchased from various slab producers in Europe. Early in 2006, this company started a supply chain implementation project to find a better balance between the different production lines, with integration of the slab ordering process. The solution consists of the integration of a number of solutions of AIS’ SteelPlanner family: BetaPlanner for the optimal scheduling of the plate mill, PIANO for the assignment and nesting of the customer plates in mother slabs, and MFC (Material Flow Coordinator) for capacity planning and synchronization of the schedules for the different production lines. This paper describes how these solutions cooperate to solve the complex logistical problems at this plate mill facility. In particular, this solution helps provide more accurate due dates, and these due dates can be met without sacrificing the quality of the schedules nor the end products. The implementation process began in February 2006 and is scheduled to finish early 2008.
3 p.m.
Modification of Reheat Furnace Practices Through Process Modeling
S. Abraham, IPSCO Inc.; D. Poshard, IPSCO Inc.; S. Chen, IPSCO Inc.
Comprehensive modeling work was performed involving a FEA thermal stress model, an FDM slab temperature model, a furnace profile model, a slab dissolving temperature model and an optimization model. The effect of a curved skid on the skidmark was taken into account and compared to the traditional straight skid. The temperature model was calibrated against the plant data. Heating criteria were established to ensure that the slab is heated and discharged with good heating qualities. Specifically, uniform bulk temperature was sought with minimal through-thickness, and skid-induced temperature gradients while respecting metallurgical requirements and achieving rapid heating rates necessary for high throughput. Incorporation of the developed models and the established heating criteria enables the optimal reheating practices to be determined to achieve a maximum throughput and/or minimum fuel consumption. This paper outlines the development, calibration and implementation of the model at the IPSCO Mobile plant.
3:30 p.m.
Micromagnetic Testing for Rolled Steel
F. Knapp, Q NET Engineering GmbH; G. Dobmann, Fraunhofer Institute for Nondestructive Testing; B. Wolter, Fraunhofer Institute for Nondestructive Testing; H. Ballmann, NDT Systems & Services AG
For hot and cold rolled steels, the mechanical-technological properties are often of central importance for acceptance testing. Conventional destructive tests are time-and cost-intensive and do not allow for continuous monitoring. In contrast, nondestructive testing (NDT) with the so-called 3MA technique allows for continuously determining mechanical properties in the moving strip. This micromagnetic multiparameter microstructure and stress analyzer is based on the fact that mechanical and magnetic properties of a ferromagnetic material are influenced by the same microstructure parameters. After calibration 3MA allows to determine tensile, yield strength and hardness. Today, fully automated 3MA testing systems for (nearly) 100 percent on-line inspection of moving steel strips are available.
4 p.m.
Width Variation Behavior During Hot Rolling
Q. Yu, Nucor Steel Tuscaloosa Inc.
Local width variation in strip length — such as width spread or shrinkage located at strip heads and tails, and other unstable rolling portions — is frequently encountered in hot rolling operations. The variation not only causes loss of process yield, but also creates problems for side trimming and welding, as well as fabricating processes. Currently, most studies on width variation concentrate on the material transverse flow in the roll bite. This study will combine the plastic deformation in the roll bite with the deformation and motion of strip outside the roll bite to analyze the behavior of the local width variation. The effect of rolling parameters (temperature, tension and speed), material characteristics, and strip shape and camber, on the width variation is investigated. The simulated results will help hot rolling operations personnel to identify the root cause of the local width variation and to establish a preventive procedure. In addition, the hidden width of strip with a poor shape is discussed.
4:30 p.m.
Modernization of a 50-year-old Heavy Plate Mill at Erdemir
S. Sener, Erdemir; M. Levick, Quad Engineering Inc.; D. Adair, Quad Engineering Inc.; Y. Liu, Quad Engineering Inc.
The ISG (Bethlehem Steel) Sparrows Point 160-inch heavy plate mill was purchased and modernized by Erdimir of Turkey. Quad Engineering Inc. was selected by Erdimir for the mill stand modernization, which included the addition of new work roll chocks and housing blocks with a double-cylinder work roll bending system for plate shape control, increased work roll diameter range for extended work roll life, and the addition of a new 10-minute quick work roll change system. This paper describes the modernization project and results.
2 p.m. — Process Technology/Sensors and Automation/Computer Applications — Automated Systems for the Steel Industry - back to top
Room 107
Session Chairs: Daniel Cunningham, Consero Inc.; Charles Sheetz, Matrix Technologies Inc.; Mark Trapp, Wheeling Pittsburgh Steel Co.
2 p.m.
Advances in Noncontact Length and Speed Measurements With Zero Speed and Automatic Direction Detection for Process Automation
L. Jenson, Beta LaserMike
Traditionally, speed and length measurements have been obtained from tachometers and encoders attached to drive rolls, tension rolls, contact wheels and idler rolls. A new gauge has been developed that can measure down to zero speed and that can also automatically determine the direction of movement. This has been accomplished by adding an acousto-optic modulator to the new gauge technology. The new gauge with zero speed and direction detection is smaller and much less expensive then older gauges with the same capability. The new gauge is also ideally suited for positioning applications, continuous caster, crop shear, guillotine shearing and many other applications that either stop or reverse direction. This paper describes the new technology, evaluates measurement data utilizing this new gauge, and summarizes test results. The usefulness of this new gauge technology is discussed, and future developments are proposed.
2:30 p.m.
A Compact X-Ray System for Direct Replacement of Existing Isotope Radiation Thickness Measurement Systems
R. Regan, Intergrated Industrial Systems Inc.; M. Zipf, Intergrated Industrial Systems Inc.; C. Hummel, Intergrated Industrial Systems Inc.
This paper presents and discusses a new, compact, fully self-contained, programmable x-ray source and detection module designed for direct retrofit replacement of sources and detectors in existing gamma gauges, while retaining their C-frames. The ion chamber–based detector is sized and tuned for the x-ray source and narrow air gap. In spite of hazardous radiation sources that require adhering to NRC rules and despite slow response time, today’s abundant use of gamma gauges in the metal industries results in the need for a more secure and faster system. The benefits of the module are presented, along with a new control and signal processing system architecture based on networked compact remote processors and FPGA technologies.
3 p.m.
Automatic On-line Coil Grading — An Innovative Software Approach
F. Luecking, Parsytec AG; E. Jannasch, Parsytec AG
This paper presents a software approach, pioneered in 2005 in three installations, to model grading decisions with rules from databases, to incorporate data from all available gauges with results on a single operator screen. The inspector no longer takes care of the obvious decisions, because the machine grading takes care of that part and at the same time provides to-the-point information for the non-obvious decision process. The unique aspects of this approach are the advanced data integration methods and software decision capabilities based on the parsytec 5i technology. Surface Excel is now operating on-line and is in the position to integrate Microsoft Excel dynamically. Hence, Excel can be used as one of the tools or components: operators can display, calculate and aggregate data in Surface Excel, whereas the charts and statistics can also be shown in Microsoft Excel. For the first time, not only rejects, but also re-route and re-assignment decisions, are possible through the integration of customer quality specification data and the access of order databases online. As a result, reduced internal rejects and a significantly improved re-assignment rate of non-prime coils to other orders have been observed.
3:30
Adding Value Through the Successful Application of Robust, Cost-effective Imaging Technology to Address Quality, Yield and Throughput Issues in the Steel Industry
V. Chupil
Traditional imaging systems have been costly, complex and difficult to implement, which has led to many failed systems in the industry. The recent emergence of "smart camera" technology has represented a step change in machine vision and has significantly reduced the cost and complexity of systems while simultaneously presenting attractive ROIs for successful installations.
This presentation will provide an overview of smart camera systems and will discuss a series of successful implementations of this technology in the environment of an integrated steelmaker. Opportunities in steelmaking and continuous casting such as remote ladle and tundish identification and comprehensive slab dimensional measurement will be presented. Examples from hot rolling through to galvanizing will be reviewed, including weld detection, slitter cobble monitoring, and remote edge tracking and steering in annealing furnaces. Elements required for successful implementation, as well as the direct benefits of these systems, will be discussed.
4 p.m.
Computational Optimal Control of a Hybrid Leaching System
A. Varvani Farahani, Petroleum Co.
Many practical systems consist of both continuous valued and discrete valued components. The term “hybrid system” has been used to describe models in which both continuous and discrete aspects are considered within the same framework. This paper presents theoretical results and experiments regarding the hybrid system, and aims to find methods for optimal control of hybrid systems. These control methods can then be applied to one hybrid system to implement the ideas in computational tools. The optimal control methods studied in this thesis are global, i.e., the entire state space is considered simultaneously rather than searching for locally optimal trajectories. The optimal value function that maps each state of the state space onto the minimal cost for trajectories starting in that state is central for global methods. In this paper, hybrid systems and hybrid control are discussed in general, optimal control and its methods are explained; and one practical system is modeled using MATLAB.
4:30 p.m.
Algorithms for Dimension Measurement of Hot Rolled Steel Products Using a CCD Camera
B. Santra, Steel Authority of India Ltd.; N. Neogi, R&D Centre for Iron and Steel, SAIL; S. Roy, R&D Centre for Iron and Steel, SAIL; B. Bhowmik, R&D Centre for Iron and Steel, SAIL; K. Rao, R&D Centre for Iron and Steel, SAIL; A. Paul, R&D Centre for Iron and Steel, SAIL; S. Llangova, R&D Centre for Iron and Steel, SAIL
In a hot rolling mill, on-line measurement of the dimension of rolled product is very important to control the roll gap so that the product dimensions are within the tolerance limit. A charge couple device (CCD) camera–based, intelligent dimension measurement system has been developed for accurate measurement of product dimensions from a distance suitable for safe operation of the camera unit. The product dimensions are calculated using the pixel information available from the CCD camera and applying the appropriate edge detection algorithm. This paper discusses various algorithms used for different types of rolled products and the relative merits and detractions of each algorithm. These algorithms have been tried for dimension measurement of rolled products sush as hot strip, billets and blooms. The measurement system developed using these algorithms has been installed in different steel plants of Steel Authority of India Limited (SAIL) and has been beneficial to the plants.
2 p.m. — Lubrication and Hydraulics — Lubrication Systems - back to top
Wabash Room 3
Session Chairs: James Sidow, Fuchs Lubricants; Walter Kusnier, NSK Corp.; Kevin Marthaler, Vogel Lubrication
2 p.m.
Conversion of a Finishing Roll Stand From Grease to Oil/air Lubrication
K. Marthaler, SKF/Vogel Lubrication Inc.
A U.S. steel producer elected to commission a finishing roll stand with oil/air lubrication instead of grease to prevent product contamination. SKF/VOGEL Lubrication developed new delivery system hardware specifically for this purpose. The roll stand was configured with bearings and seals to optimize this application. Unique oil streak sensors were employed for constant electronic monitoring of each lube point.
2:30 p.m.
Air/oil — Advantages and Disadvantages
J. Schlobohm, BP/Castrol
What advantages do air/oil systems have over conventional grease lubricating systems? What drawbacks are there? These and other questions, as well as engineered system design, will be discussed in this paper. Proper bearing housings, seals, piping size and air pressures are all critical to the success of the lubricating system. The concept of air/oil is to transfer enough oil to the bearing to provide adequate lubrication, while putting a small positive pressure on the housing to keep water and dirt from contaminating the rolling elements. This paper will also discuss how proper oil selection can have a long-term effect on bearing life and lubrication efficiency.
3 p.m.
The Envirolube™ Air Grease Lubrication System
D. Preshaw, Corus Process Engineering; B. Stalker, Corus Process Engineering; K. Goode, Corus Process Engineering; R. Worsley, Corus Construction & Industrial
A new air grease lubrication system has been developed by Corus. After workshop bench testing and proving trials, a slab caster straightener roller has been converted and successfully operated for the past two years. Other systems are now being implemented for slab and bloom caster bow equipment. Advantages of this new system include: significantly reduced grease consumption, minimal adjustment to existing grease feeding systems, lower internal operating temperatures resulting from the air scouring the bearings, and significantly reduced environmental contamination. Most existing bearing assemblies can be converted easily by modifying the sealing arrangements, allowing older equipment to achieve greater in-service life. The system is applicable to bearings operating in contaminated environments such as the rollers of continuous casters and rolling mills.
3:30 p.m.
Grease 101 — Basics of Lubricating Grease With a Focus on the Steel Industry
F. Blancett, Fuchs Lubricants Co.
This presentation covers the basic components and types of lubricating greases with a focus on the steel industry and its unique challenges. The various thickeners, base oils, and their applications and advantages are discussed. Also covered in detail are the various laboratory tests of greases and how this testing relates to real-world applications in the steel industry.
4 p.m.
Effective Design of Oil Analysis Programs
M. Stanbary, Castrol Industrial North America Inc., J. Haspert Castrol Industrial North America Inc.
4:30 p.m.
Experimental Measurement of Oil Film Thickness and Dynamic Oil Film Response of Oil Film Backup Bearings for Backup Roll Applications
A. Martins, Morgan Construction Co.; P. Osgood, Morgan Construction Co.; T. Wojtkowski, Morgan Construction Co.; E. Winslow, Morgan Construction Co.
Recent experiments have shown that large oil film bearings common in steel mill applications follow the principles of elasto-hydrodynamic lubrication (EHD). This paper presents test results illustrating measured EHD oil film thickness of two different types of bearings. It also presents the dynamic response of the oil film in response to step changes in speed for two specific cold mill applications. Data for oil film response to sudden stopping and lubricant starvation are also discussed.
2 p.m. — Project and Construction Management — Completed Projects - back to top
Room 109
Session Chairs: Tom Zacharewicz, Dofasco Inc., Don Salsbury, Middough Consulting Inc., Don Osterhout, SNC - Lavalin America, Inc.
2 p.m.
The Modernization of the Hot Strip Mill at JSW Steel’s Toranagallu Plant: Modernization Project Case Study
B. Hunt, Siemens VAI; A. Aggarwal, JSW Steel Ltd.
The modernization of the hot strip pill at Indian steel producer JSW’s Toranagallu plant, intended to improve mill throughput, reliability and product quality, is an integral part of the company’s ambitious expansion plans. The project was executed by JSW together with Siemens, the main contractor and technology provider for mechanical equipment, mill main drives, automation systems and process control. The success of this project is a result of the cooperation between JSW and Siemens in managing the execution of the project, in particular the planning and supervision of the extensive shutdown. This paper, presented jointly by Siemens and JSW, will be of interest to companies planning similar modernization projects.
2:30 p.m.
The New Steelmaking Plant for SBQ Steels at Charter Steel, Cleveland, Ohio
C. Travaglini, Danieli & C Spa
On June 15, 2006, first heats were successfully performed at the new Charter Steel state-of-the-art special steel meltshop, which is designed to support Charter Steel’s existing rod and bar-in-coil rolling mill in Cuyahoga Heights, Ohio. The plant is basically made up of a 75-ton EAF, LF, single-tank VD, and a 4-strand conticaster for up to 200-mm square billets in various grades ranging from carbon to alloy steels for cold heading, cold forging, specialty spring, bearing, high-carbon, and free-machining steels for automotive, aerospace, agricultural and construction applications. Plant highlights and results will be detailed in this paper.
3 p.m.
Fast Tracking for Flexibility
D. Dennison, Republic Engineered Products; J. Kushner, Republic Engineered Products
3:30 p.m.
No. 2 Continuous Pickle Line Cold Mill Project (No. 2 CPCM)
T. Szkut, Dofasco Inc.
In 2002, Dofasco reviewed its current position in the North American market relative to its competitors. The review identified opportunities for improvement which, in turn, defined strategies to improve Dofasco’s competitiveness in the marketplace. A large number of improvement projects were identified and captured under the banner of Finishing Division Improvement Program of FDIP.
The No. 2 CPCM project is the single largest project in the FDIP portfolio and spanned nearly three and a half years from concept to completion. The implementation was divided into two parts. The first was the construction and commissioning of a new pickle line in an existing building and the second was the revamp of an existing cold mill. The final step was to connect the two facilities together to create a continuous pickling and cold rolling facility.
The presentation will discuss the approach taken to undertake two brownfield projects and later combine them into a single facility. It will outline the project objectives, implementation strategies, execution including cold mill outages, risk mitigation strategies, project results and lessons learned.
4 p.m.
Construction and Commissioning of 2MTPY Automatic Packing Line at Mittal Steel, Indiana Harbor Works
M. Cummings, Mittal Steel USA, T. Aijo, Pesmel North America; E. Strom, Pesmel North America; J. Rajagopalan, Pesmel North America
Packing and shipping are renowned bottle necks in every plant. Automatic line for packing could be the best solution but it has been a Taboo in Steel Industries to accept completely automatic packing line which has no precedence. Mittal Steel, Indiana Harbor works have benchmarked and consolidated their packing needs and have installed a Centralized computer controlled Automatic packing line with programmable packing feature with a capacity of 20 full coils/hr to address shipping of approx 2 Million tons per year. Micro planning, Module concept Technical specification, flexibility for upgrades, Shop test and pre commissioning, Organized construction and installation work and Structured start up and production ramp up to insure better IRR and ROI are the good points and are shared in this paper.
4:30 p.m.
Replacement of the No. 1 Coke Plant Quench Tower at Dofasco
P. Roppel, Dofasco Inc.; M. Luscombe, Dofasco Inc.; T. Maurice, Dofasco Inc.
The unique challenge of constructing a new quench tower at Dofasco’s No. 1 coke plant was the coordination of construction and plant operation within the same working space. To construct a new process structure within the confines of a brownfield site, the coking schedule was adapted to allow construction to be carried out with minimal interference to the continuous operating facility. Safe construction of the new tower required a reduction in coking rate with careful consideration of coke oven integrity. This presented a rare opportunity for a major overhaul of 50-year-old equipment and facilities.
2 p.m. — Energy and Utilities — Energy Outlook and the Steel Industry - back to top
Room 104
Session Chairs: Peter Harschnitz, Dofasco Inc.; Christopher Williams, Rad-Con Inc.
2 p.m.
Energy Outlook and the Steel Industry Panel Discussion
Moderator: J. Stubbles
Panelists:
A. Thekdi, president, E3M Inc.
T. Ondrey, senior project engineer, U. S. Steel
S. Holte, technical assistant to the administrator, Energy Information Administration
R. Downie, corporate environmental manager, Gerdau Ameristeel Corp.
3:30
Ovako, Hofors Works - 13 Years Experience of Using Oxyfuel for Steel Reheating — Background, Solutions and Results
P. Fredriksson, Ovako Steel, E. Claesson, Ovako Steel, P. Vesterberg, Linde Gas, G. M oroz, Linde Gas LLC
4 p.m.
In-situ Oxygen Sensors for Fuel Savings and Scrap Reduction in Reheat Furnaces
B. Knight, Marathon Sensors Inc.; K. Taylor, Marathon Sensors Inc.; E. Boltz, Marathon Sensors Inc.; P. Barker, Marathon Sensors Inc.; Y. Boltz, Marathon Sensors Inc.
High-temperature, in-situ oxygen sensors have been used to control the trim of air-to-fuel ratios in reheat furnaces. Unlike analyzers termed “close-coupled,” these sensors have the active sensing element within the furnace. This eliminates lag time in sensor response found in extractive or close-coupled systems, thereby allowing real-time control with response times on the order of fractions of a second. Excess air can be controlled to the 1–2 percent range, resulting in substantial scale reduction, fuel savings and NOx emissions reductions. With new, mixed-fuel furnaces, where fuel BTU content varies widely, the advantages of real-time trim control are expected to be improved further.
4:30 p.m.
Reheat Furnace Fuel Switching Technical Paper
W. McPherson, DTE Energy Services; P. Debski, Bricmont Inc.; M. Fenton, Aecometric Corp
The convenience and environmentally friendly aspects of natural gas make it the fuel of choice for most mill furnaces. However, gas costs are increasingly putting pressure on mill profits. Pulverized coal, fed pneumatically to the heat zone of existing reheat furnaces, is an economically attractive alternative. Trials show efficient combustion of coal in burners as small as 5 mmBtu/hour with no significant increase in scaling or surface inclusions. Emissions are controlled with readily available technologies. Fuel savings are sufficient to provide an acceptable capital recovery for many furnaces. |
