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Sample records for rolling mill rolls

  1. NUMERICAL EVALUATION OF TEMPERATURE DISTRIBUTION IN THE ROLLING MILL ROLLS

    José Claudino de Lira Júnior

    2013-06-01

    Full Text Available In hot rolling processes occur changes in the profile of the rolling mill rolls (expansion and contraction and constant wear due to mechanical stress and continuous thermal cycles of heating/cooling caused by contact rolled material- working roll and the cooling system by water jets in their surface, decreasing their lifetime. This paper presents a computational model to simulate the thermal performance of rolling mill rolls. The model was developed using the finite volume method for a transient two-dimensional system and allows calculating the temperature distribution of the rolling mill rolls under various conditions of service. Here it is investigated the influence of flow rate and temperature of the cooling water on the temperature distribution. The results show that the water temperature has greater influence than the water flow to control the surface temperature of the cylinders.

  2. Control for Cold Rolling Mills

    Morad, Antoni; Travancic, Faruk

    2005-01-01

    This report contains the details in a final research thesis work done rolling mill technology. The work is carried out at Heat Transfer located at Finspång. The main objective of this work is to evaluate thickness and flatness data from the profile to give an optimal start value for the pressure and force applied on the machine and the speed as well, so that the profiles produced, have the right thickness and best possible flatness. Thickness, start value for power, the degree of bending the ...

  3. Analysis of Roll Gap Pressure in Sendzimir Mill by FEM

    YU Hai-liang; LIU Xiang-hua; WANG Chao; Park Hae-doo

    2008-01-01

    The acting force on the roll system of Sendzimir mill was analyzed using 3D FEM. The roll gap pressure distribution and the acting force between rolls S and O, rolls O and I, rolls O and J, rolls I and A, rolls I and B, as well as rolls J and B were analyzed. The results showed that the roll gap pressure mainly affected the roll surface layer, 50 mm for backup roll; the roll gap pressure distribution is of double peaks among the work roll, the 1st intermediate roll (IMR), and the 2nd IMR; the maximum value of the roll gap pressure between the backup roll and the second IMR appears on the edge of the barrel of rolls; the component force presents the in-para-curve distribution. These are important for reducing the wear of rolls and the break of the backup roll and guiding for production.

  4. Tribology; Cold rolling mill roll; Hard chrome; Surface texturing.

    José Lucio Gonçalves Junior

    2012-12-01

    Full Text Available The present work analyzes the tribological behavior of surface modifications often used in cold rolling mill rolls. Different surface modifications were carried out on samples produced from a fragment of the rolling mill roll: i texturing; ii chromium plating; iii texturing with subsequent hard chrome plating; iv and hard chrome plating with subsequent texturing. Before the surface modifications the samples were heat treated and ground on both faces. Wear tests were performed using a reciprocating movement of a ball over flat configuration under a load of 9.8 N. It is observed that there is no significant change in the coefficient of friction as a function of surface modification. Surface texturing increases the wear of the counter body, while the hard chromium coating reduces it. The addition of hard chromium coating promotes the formation of a tribolayer on the counter body consisting of chromium and oxygen. On the other hand, for the samples without hard chrome coating, the tribolayer consists of iron and oxygen

  5. Investigation for parametric vibration of rolling mill

    唐华平; 丁睿; 吴运新; 钟掘

    2002-01-01

    The vibration unsteady condition of rolling mill caused by flexural vibration of strip has been investigated. The parametric flexural vibration equation of rolled strip has been established. The parametric flexural vibration stability of rolled strip has been studied and the regions of stability and unstability have been determined based on Floquet theory and perturbation method. The flexural-vibration of strip is unstable when the frequency of variable tension is two times as the natural frequency of flexural-vibration strip. The characteristic of current in a temp driving motor's main loop has been studied and tested, it has been proved that there are 6 harmonic component and 12 harmonic component in main loop of driving motor electricity. The vertical vibration of working roller has been tested, the test result approves that the running unsteady is caused by parametric vibration. It attaches importance to the parametric vibration of rolling mill.

  6. Novel tube-rolling process using the 3-roll planetary mill (PSW)

    Bretschneider, E.J.F.E.

    1981-10-01

    A high-reduction, 3-roll planetary mill for the production of seamless tube is described and compared with conventional methods. Advantages include continuous rolling, close wall tolerance, increased yield and energy savings.

  7. Metallurgical analysis of spalled work roll of hot strip mill

    In this study failure analysis of four work roll of the Hot Strip Mill is carried out. The microstructure is correlated with the chemical composition of shell and roll-life. It was concluded that for the longer service of the roll, cementite, graphite and martensite should be balanced (as per working requirement of the mill). (author)

  8. Work Roll Materials For Hot Strip Milling and Casting Methods of Rolling Roll

    Şadi KARAGÖZ

    2009-03-01

    Full Text Available The selection of materials for rolling, which is one of the powerful manufacturing process and the influence of these materials on the roll properties is an important factor. Also, the use of suitable material and various manufacturing technologies affect these characteristics. To understand that which roll grade is needed for which application, the rolling conditions, the roll grades and their properties should be known. In this work the evolution of roll materials from classical materials up to recently developed materials are presented and bimetallic roll technologies are investigated. Furthermore, experimentally cast pearlitic and martensitic roll microstructures were examined. The influence of microstructural phases on the roll properties were analyzed with the results of mechanical and microstructural observations.

  9. Structural investigations of HSS rolls for hot strip mill

    Lecomte-Beckers, Jacqueline; Tchuindjang, Jérôme Tchoufack; Ernst, R.; Breyer, J.-P.

    2004-01-01

    High Speed Steel (HSS) cast rolls are used in front finishing stands of hot strip mills (HSM). Good wear resistance and hardness at high temperatures, are defining features of HSS. Previous experience has shown that HSS rolls containing mainly hard MC carbides have a high friction coefficient, which is detrimental for the rolling power consumption and for the strip surface quality. On the other hand, HSS rolls containing eutectic rod shaped carbides are brittle and more susc...

  10. Backup roll contour of a SmartCrown tandem cold rolling mill

    Guanghui Yang; Jianguo Cao; Jie Zhang; Shenghui Jia; Renwei Tan

    2008-01-01

    SmartCrown was a new system developed by VAI for improving the strip profile and flatness control first applied in 1700mm tandem cold rolling mills at Wuhan Iron & Steel (Group) Corporation (WISCO). After tracing and testing, the application of the conventional crown backup roll matching the SmartCrown work roll of the production mill led to heavy and nonuniform wear, and the edge spalling of the backup roll often occurred. A 3-dimension finite element model of roll stacks was established, which was used to analyze the above-mentioned problems, and it was found that the main reason was the highly nonuniform contact pressure distribution between the work roll and the backup roll. A new FSR (flexible shape backup roll) was developed and applied in 1700mm tandem cold rolling mills. A lot of good actual effects of FSR, such as evident improvement in profile and flatness of strips,non-occurring edge spalling, wear uniform, and remarkable decrease in roll consumption were validated by long-term industrial applications.

  11. Analysis of rolls deflection of Sendzimir mill by 3D FEM

    YU Hai-liang; LIU Xiang-hua; LEE Gyoo Taek

    2007-01-01

    The deflection of rolls of Sendzimir mill with double AS-U-Roll was simulated by finite element method(FEM). The influences of rolling pressure, strip width and rolls-assignment on rolls deflection were analyzed. The results show that the work roll deflection increases with the increase of rolling pressure and the reduction of work roll radius, but the rigid displacement of work roll slightly changes; the work roll end might appear negative displacement for the narrow strip width and high rolling pressure that might cause the contact of work rolls. The research results are significant for guiding production and theoretical analysis of the rolls system of Sendzimir mill.

  12. Analysis of Vertical-Horizontal Coupling Vibration Characteristics of Rolling Mill Rolls Based on Strip Dynamic Deformation Process

    Dongxiao Hou; Rongrong Peng; Haoran Liu

    2014-01-01

    Nonlinear dynamic rolling forces in the vertical and horizontal directions are, respectively, established, considering the impact of vertical and horizontal directions vibration of rolls. Then a vertical-horizontal coupling nonlinear vibration dynamic model of rolling mill rolls is proposed, based on the interactions between this dynamic rolling force and mill structure. The amplitude-frequency equations of the main resonance and inner resonance are carried out by using multiple-scale method....

  13. Theoretical foundations of the automated designing of assembly drawings of rolls of wheel rolling vertical type mills

    Снітко, С. О.; Яковченко, О. В.; Івлєва, Н. І.

    2014-01-01

    Automated designing inker, pressure and conical rolls, as well as centering and driving rollers of modern wheel-rolling mills of vertical type required for the development of new highly effective profile of railway wheels is actual scientific and technical problem. In this paper, first proposed the theoretical foundations of the automated design drawings of rolls of vertical type wheel-rolling mills. The designing of circuits of pressure and inker rolls and calculation values technological ga...

  14. Investigation for Electromechanical Coupling Unstability of Rolling Mill

    2002-01-01

    The unsteady condition of rolling Mill vibration that was caused by flexural vibration of strip was investigated. The parametric flexural vibration equation of rolled strip was established. The parametric flexural vibration stability of rolled strip was studied and region of stability and unstability was determined based on Floquet theory and perturbation method. The flexural-vibration of strip was unstable if the frequency of variable tension was twice as the natural frequency of flexural-vibration strip. ...

  15. Evaluation of Flatness Gauge for Hot Rolling Mills

    Larsson, Oliver

    2015-01-01

    In the steel industry, laser triangulation based measurement systems can be utilizedfor evaluating the flatness of the steel products. Shapeline is a company in Linköpingthat manufactures such measurement systems. This thesis work will present a series ofexperiments on a Shapeline measurement system in a relatively untested environment, thehot rolling mill at SSAB in Borlänge.The purpose of this work is to evaluate how the conditions at a hot rolling mill affectsthe measurement performance. I...

  16. Dynamic estimation of electrical demand in hot rolling mills

    Alonso Orcajo, Gonzalo Arturo; Rodríguez, Josué; Ardura García, Pablo; Cano Rodríguez, José Manuel; González Norniella, Joaquín; Llera Traviesa, Rocío; Cifrián, Diego

    2016-01-01

    This paper proposes a method capable of reproducing the particular operating conditions of a hot strip mill and predicting the evolution of the main electrical variables from both the characteristics of the steel to be milled and the specific features of the rolling mill. The method analyzes the load torque and the motor speed evolution in the stands of the roughing and finishing mill drives, according to the steel to be milled. In this study three types of carbon alloy steel are considered, ...

  17. Service behaviour of high speed steel rolling rolls used in hot strip mills

    Work rolls used in hot strip mills may be able to carry out severe actions: very high thermal stresses and wear, along with mechanical stresses due to normal rolling loads, which develop in the presence of cracks, produced by the former actions. The microstructure and the mechanical behaviour (strength and toughness) of high speed steels, which recently have been introduced in this applications, were studied in this work in comparison with high chromium cast irons. (Author) 7 refs

  18. Optimization of Rolling Force Distribution Based on Niche Genetic Algorithm in Continuous Hot Rolling Mills

    LIU Zi-ping; LI Li-xin

    2013-01-01

    Based on the niche genetic algorithm, the intelligent and optimizing model for the rolling force distribution in hot strip mills was put forward. The research showed that the model had many advantages such as fast searching speed, high calculating pre-cision and suiting for on-line calculation. A good strip shape could be achieved by using the model and it is appropriate and practica-ble for rolling producing.

  19. Performance characteristics of mill rolls from graphite chromium cast iron

    Lecomte-Beckers, Jacqueline; Terziev, L.; Breyer, J. P.

    2000-01-01

    The main requirements for the development of a new grade for the later finishing section of the mill are : good oxidation and thermal behaviour, high wear resistance, good resistance to rolling incidents. The approach of Marichal Ketin to improve the rolling performances in the last finishing stands is presented. The Hi-Cr cast iron possesses excellent wear resistance due to the presence of hard chromium carbides, but its thermal conductivity and sticking properties are fairly low. A graphite...

  20. Development of rolling mill for rectangular orthodontic wires production

    G.E. Totten

    2007-09-01

    Full Text Available Purpose: In orthodontic treatments, wires of different metallic alloys are used for alignment, leveling, correction of the molar position, space closing, finish and retention. The purpose of the paper is the characteristics of austenitic stainless steel wires, with a square traverse section, which were produced using a rolling mill built for this purpose, are presented hereDesign/methodology/approach: With respect to finish and retention, these wires are responsible for adequate positioning of the upper teeth on the lower teeth. Wires that are subjected to incisor torque require high resistance and stiffness. For this, wires of rectangular austenitic stainless steel are used due to high modulus of elasticity and good corrosion resistance in the oral environment. Because of the rectangular geometry, wire production requires process development suitable for industrial scale manufacture with geometric characteristics and mechanical properties better adapted to the use conditions.Findings: To obtain wires with such characteristics, a rolling mill was developed for the production of rectangular wires by a rolling process with the objective of reducing cost of the cold drawing process that is currently used which utilize complex and expensive wire-drawing dies. In addition to the rolling process itself, wire deformation, microhardness, tension and bend tests were also performed.Research limitations/implications: A rolling-mill was built that successfully produced dental wires within acceptable tolerances and physical/mechanical properties.These wires exhibited excellent hardness and tensile strength, although slightly less than analogous commercial wires. It is expected that this problem are corrected by using initial wires with a higher hardness, since this property is directly related with the tensile strength.Originality/value: In these tests, wire geometry, surface finish and mechanical properties were successfully adapted for use in orthodontic

  1. Recycle of valuable products from oily cold rolling mill sludge

    Liu, Bo; Zhang, Shen-gen; Tian, Jian-jun; Pan, De-an; Liu, Yang; Volinsky, Alex A.

    2013-10-01

    Oily cold rolling mill (CRM) sludge contains lots of iron and alloying elements along with plenty of hazardous organic components, which makes it as an attractive secondary source and an environmental contaminant at the same time. The compound methods of "vacuum distillation + oxidizing roasting" and "vacuum distillation + hydrogen reduction" were employed for the recycle of oily cold rolling mill sludge. First, the sludge was dynamically vacuum distilled in a rotating furnace at 50 r/min and 600°C for 3 h, which removed almost hazardous organic components, obtaining 89.2wt% ferrous resultant. Then, high purity ferric oxide powders (99.2wt%) and reduced iron powders (98.9wt%) were obtained when the distillation residues were oxidized and reduced, respectively. The distillation oil can be used for fuel or chemical feedstock, and the distillation gases can be collected and reused as a fuel.

  2. Variable-speed drive and control systems for rolling mills; Atsuenkiyo drive seigyo system

    Kasai, T.; Tochigi, T. [Fuji Electric Co. Ltd., Tokyo (Japan)

    2000-11-10

    The drive systems of large rolling mills is of a cycloconverter type, a GTO (gate turn-off thyristor) type or high-voltage IGBT (insulated gate bipolar transistor) type. Drive systems for bar, rod and pipe mills use three and/or two level IGBT inverters. This paper describes recent technical trends of drives and control systems in rolling mills, including each drive application and the PLC (programmable controller) and HCI (human communication interface) controlling the total rolling mill line. (author)

  3. Numerical And Experimental Study On Producing Aluminum Alloy 6061 Shafts By Cross Wedge Rolling Using A Universal Rolling Mill

    Tofil A.

    2015-06-01

    Full Text Available The paper presents a selection of numerical and theoretical results of the cross wedge rolling process for producing stepped shafts made of aluminum alloy 6061. The numerical modeling was performed using the FEM-based Simufact Forming simulation software. In the simulations, we examined the kinematics of metal flow and determined the distribution patterns of effective strains, temperatures, axial stresses and the Cockroft-Latham damage criterion. Variations in the rolling forces were determined, too. The numerical results were verified experimentally using a universal rolling mill designed and constructed by the present authors. This machine can be used to perform such processes as cross wedge rolling, longitudinal rolling and round bar cropping. During the experiments, we examined process stability and finished product geometry and recorded the torques. The experimental results confirm that axisymmetric aluminum alloy shafts can be produced by cross wedge rolling with two rolls. Last but not least, the experiments served to evaluate the technological potential of the rolling mill used.

  4. Bayesian model mixing for cold rolling mills: Test results

    Ettler, P.; Puchr, I.; Dedecius, Kamil

    Slovensko: Slovak University of Technology, 2013, s. 359-364. ISBN 978-1-4799-0926-1. [19th International Conference on Process Control . Štrbské Pleso (SK), 18.06.2013-21.06.2013] R&D Projects: GA MŠk(CZ) 7D09008; GA MŠk 7D12004 Keywords : Bayesian statistics * model mixing * process control Subject RIV: BC - Control Systems Theory http://library.utia.cas.cz/separaty/2013/AS/dedecius-bayesian model mixing for cold rolling mills test results.pdf

  5. Development of high-speed tool steel roll and its application to rolling mill; Koseino haisuroru no kaihatsu to atsuen bun`ya eno tekiyorei

    Takigawa, H.; Tanaka, T.; Otomo, S.; Hashimoto, M. [Nippon Steel Corp., Tokyo (Japan)

    1997-07-30

    Technical development in the field of steel rolling in recent years has been carried out from the viewpoints of improving the quality of steel products, improving the productivity, and reducing the manufacturing costs. With this technical development, a need for the highly reliable rolling mill roll with a high performance and a long life has extensively grown. Thereupon, the authors have developed a rolling mill roll called the high-speed tool steel roll. This roll was originally designed for the finishing stands of hot strip mill, and it demonstrated a high performance when using. As the result, the quality of rolled steel products has been improved and such restrictions on rolling operation resulted from the mill rolls have been sharply eased. On the basis of these successful results, the said roll has been also extensively applied in other fields of material rolling. This paper introduces the development of this high-speed tool steel roll and some examples of its application, together with results obtained. 5 refs., 15 figs., 2 tabs.

  6. Friction Coefficient Between Rolling Tube and Mandrel of Full Floating Mandrel Mill

    ZHAO Zhi-yi; XIE Jian-xin; HE Xiao-ming; DONG Kai; YU Yong; PAN Feng

    2009-01-01

    In the process of steel tube production, continuous tube rolling is the foremost forming procedure and the critical step that decides the dimension precision and the surface quality. In the actual production of the φ140 mm full floating mandrel mill in Steel Tube Branch in Baosteel, steel T91 was chosen to be the typical sample, self-made roll-ing force transducer and mandrel velocity testing equipment were used, and a series of comprehensive tests on rolling parameters including the rolling force and mandrel velocity were carried out. After the experiment, the friction state between rolling tube and mandrel was analyzed. The friction coefficient was calculated and the values of 0.033-0.074 in each mill were obtained. The friction coefficient increases obviously along the rolling direction.

  7. USE OF HIGH SPEED STEEL WORK ROLLS (HSS ON APERAM STECKEL MILL

    Arísio de Abreu Barbosa

    2013-12-01

    Full Text Available This paper outlines the main actions taken to reinforce the decision to use HSS work rolls on the Aperam Steckel Mill. These are: work roll cooling improvements, systematically analyzing Eddy Current and Ultrasonic non destructive tests, mechanical adjustment of work roll crown and critically examining the rolling process. These actions applied together have contributed to the success of HSS rolls state of the art application, and provide the Steckel Mill with a much improved performance. Significant results have been achieved, such as: increasing of work roll change intervals, increasing of the available production time, a yield gain, a product quality improvement, less working hours needed for the roll grinding operation, etc

  8. Design of Rolling State Observers for Application to Control of Thickness and Tension in Rolling Mills

    Hamid R. Koofigar

    2011-09-01

    Full Text Available This study focuses on the necessity of designing state observers to be used in controller synthesis for rolling processes. This is motivated by the fact that using several kinds of sensors for measuring all of process variables is technically and economically avoided. On the other hand, using exact measurement in feedback control systems could considerably improve the quality of products. In other word, there is a trade-off between high quality and the implementation limitations, managed here by developing rolling state observers. The proposed observers estimate the states not measured directly by the installed sensors. This technique is applicable to both hot rolling and cold rolling processes. Simulation results demonstrate the performance of the proposed estimation algorithm.

  9. Study on the improved accuracy of strip profile using numerical formula model in continuous cold rolling with 6-high mill

    The quality requirements for thickness accuracy in cold rolling continue to become more stringent. In cold rolling mill, it is very important that the rolling force calculation considers rolling conditions. The rolled strip thickness was predicted using calculated rolling force. However, the prediction of strip thickness in cold rolling is very difficult; in particular, for 6-high mill with shifted intermediate roll (IMR), the accuracy of thickness is not good. In this study, to improve the accuracy of rolled strip thickness, the roll gap flattening can be given based on Hertz contact theory, with contact between rolls and the smooth cylindrical rolls for the rolling elastic deformation. Also, the distribution of the roll gap flattening may be calculated using the contact force of unit transverse length. The strip profile at the continuous cold rolling is calculated by using the numerical analysis model considering the initial strip profile before cold rolling. Hence, we propose that the numerical model can predict the rolled strip profile more quickly and accurately and be applicable to the field. The results of the proposed numerical model were verified by FE-simulation and cold rolling experiments of 6-high mill with five stands

  10. Hot sheet rolling on continuous mill under plastic fluid friction conditions

    A technique for hot sheet rolling in plastic fluid friction conditions of sheets of the 12Kh18N10T and carbon 10 sp steels is developed and tested. A new lubricant ''Silicatherm'' constitutes the basis of the technique. The advantages of the given technique as compared to the rolling with liquid lubricants of mineral and vegetative origin as well as the prospects of its introduction during hot rolling on continuous mills are shown

  11. Effect of roll-compaction and milling conditions on granules and tablet properties.

    Perez-Gandarillas, Lucia; Perez-Gago, Ana; Mazor, Alon; Kleinebudde, Peter; Lecoq, Olivier; Michrafy, Abderrahim

    2016-09-01

    Dry granulation is an agglomeration process used to produce size-enlarged particles (granules), improving the handling properties of powders such as flowability. In this process, powders are compacted using a roll press to produce ribbons, which are milled in granules used further in the tableting process. The granule and tablet properties are influenced by the existence of different designs of the roll compactors, milling systems and the interaction between process parameters and raw material properties. The main objective of this work was to investigate how different roll-compaction conditions and milling process parameters impact on ribbons, granules and tablet properties, highlighting the role of the sealing system (cheek plates and rimmed roll). In this context, two common excipients differing in their mechanical behaviour (MCC and mannitol) are used. The study is based on the analysis of granule size distribution together with the characterization of loss of compactability during die compaction. Results show that the tensile strength of tablets is lower when using granules than when the raw materials are compressed. Moreover, the plastic material (MCC) is more sensitive than the brittle one (mannitol). Regarding the roll-force, it is observed that the higher the roll force, the lower the tensile strength of tablets from granulated material is. These findings are in agreement with the literature. The comparison of sealing systems shows that the rimmed-roll system leads to slightly stronger tablets than the use of cheek plates. In addition, the use of the rimmed-roll system reduces the amount of fines, in particular when high roll force is applied. Overall, it can be concluded that roll-compaction effect is predominant over the milling effect on the production of fines but less significant on the tablet properties. This study points out that the balance between a good flowability by reducing the amount of fines and appropriate tablet strength is achieved with

  12. IMPROVEMENT PROCESS FOR ROLLING MILL THROUGH THE DMAIC SIX SIGMA APPROACH

    Kunal Ganguly

    2012-09-01

    Full Text Available This project aims to address the problems that are facing a large aluminum company in a Developing Hot Rolling Mill Capabilities for Wider Widths Hard Alloys Rolling and b Eliminate down time due to strip /coil slippage during hard alloys 5xxx rolling at Hot Mill. The challenge for the company was to cater the fast changing export demand for Flat Rolled products with its existing resources. By applying Six Sigma principles, the team identified the current situation that the rolling mills operations were in. Si x Sigma DMAIC methodologies were use d in the project to determine the project's CTQ characteristics, defining the possible causes, Identifying the variation sources, establishing variable relationships and Implementing Control Plans. The project can be useful for any company that needs to fi nd the most cost efficient way to improve and utilize its resources.

  13. Premature failure analysis of forged cold back-up roll in a continuous tandem mill

    Highlights: → Metal wrapping and strip welding in work/back-up rolls contact zone caused spalling. → MnS inclusion and pore initiated crack which propagated in milling led to spalling. → Retained austenite conversion to α'-martensite accelerated spalling failure. → Needle shaped carbide (Fe,Mo,Cr)7C3, may cause poor service life of back-up roll. -- Abstract: In this paper, premature failure of a forged back-up roll from a continuous tandem mill was investigated. Microstructural evolutions of the spalled specimen and surface of the roll were characterized by optical microscopy, X-ray diffraction, scanning electron microscopy and ferritscopy, while hardness value of the specimen was measured by Vickers hardness testing. The results revealed that the presence of pore and MnS inclusion with spherical and oval morphologies were the main contributing factors responsible for the poor life of the back-up roll. In addition, metal pick up and subsequently strip welding on the surface of the work roll were found as the major causes of failure in work roll which led to spalling occurrence in the back-up roll. Furthermore, relatively high percentage of retained austenite, say 9%, in outer surface of the back-up roll contributed spalling due to conversion of this meta-stable phase to martensite and creation of volume expansion on the outer surface through work hardening during mill campaign.

  14. Force prediction in cold rolling mills by polynomial methods

    Nicu ROMAN

    2007-12-01

    Full Text Available A method for steel and aluminium strip thickness control is provided including a new technique for predictive rolling force estimation method by statistic model based on polynomial techniques.

  15. Fuzzy-Neural Control of Hot-Rolling Mill

    Khearia Mohamad; Abduladhem A. Ali; R. Nagrajan

    2010-01-01

    This paper deals with the application of Fuzzy-Neural Networks (FNNs) in multi-machine system control applied on hot steel rolling. The electrical drives that used in rolling system are a set of three-phase induction motors (IM) controlled by indirect field-oriented control (IFO). The fundamental goal of this type of control is to eliminate the coupling influence though the coordinate transformation in order to make the AC motor behaves like a separately excited ...

  16. Metallurgical assessment of two HSS rolls grades for Hot Strip Mill

    LECOMTE-BECKERS, Jacqueline; Fabienne DELAUNOIS; Breyer, Jean-Pierre; Tchuindjang, Jérôme Tchoufack

    2007-01-01

    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 Rays analysis on carbides and Differential Thermal Analysis. These methods allow a better understanding of the behaviour of the studied alloys during solidification and cooling. Some mechanical tests were also performed. A connection between the laboratory results and the perf...

  17. INVESTIGATION OF THE MAINTENANCE ORGANISATION FOR HOT ROLLING MILLS

    P.K. Pretorius

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: Production systems have undergone dramatic changes in recent years. Many companies have implemented new technologies such as flexible manufacturing systems. There is therefore a shift in focus to maintenance and the effective management thereof. Maintenance is a dynamic activity and is comprised of a large number of interacting variables. An effective maintenance organisation is required to control these variables .
    This paper discusses the building of a maintenance organisation and the aspects that should be considered during the design. The way in which five companies that operate hot rolling mills apptoached the problem of building an effective maintenance organisation was investigated.

    AFRIKAANSE OPSOMMING: y eryaardigingstelsels het drastiese veranderinge ondergaan die afgelope aantal jaar. Verskeie Il1~atskappyemaak nou gebruik van nuwe tegnologiee, soas byvoorbeeld aanpasbare vervaardigingstelsels. Daar is gevolglik 'n verskuiwing in fokus na instandhouding en die effektiewe bestuur daarvan. lnstandhouding is 'n dinamiese aktiwiteit en behels 'n groot aantal ' gekoppelde veranderlikes. 'n Effektiewe instandhoudingsorganisasie word benodig om hierdie v'eranderlikes te beheer.
    Hierdie artikel bespreek die daarstelling van die instandhoudingsorganisasie en die parameters V~toorweeg moet word tydens die ontwerp. Die wyse waarop vyf maatskappye wat }V~rIl1walse bedryf die ontwikkeling van 'neffektiewe organisasie vir instandhouding benader hc(is ondersoek .

  18. Drop deformation in two-roll mills considering wall effects

    Experimental, theoretical and numerical results of dynamics of drop deformation in strong flows generated by a co-rotating two-roll mill and considering the influence of near rigid walls are presented. The drop dynamics is altered, with respect to a drop free of wall effects, by the proximity of the rigid boundaries as well as caused by a non-linear and non-uniform flow due to gradients of flow-type parameter and shear rate. Simulations were carried out using the Boundary Element Method (BEM). Since the inclusion of the whole boundaries (drop and rollers surfaces) is not an easy and trivial task, bi-dimensional numerical simulations was performed as a first approach. The experimental and numerical results were obtained for a flow type of α = 0.03 and two values of viscosity ratio λ = 0.012 and 16. In general, numerical results for the stationary deformation parameters, up to intermediate confinements, are in agreement with the experiments, with and without wall effects. Since the case of drops with a high viscosity ratio did not match existing theoretical models, the wall-effect theory of Shapira and Haber was modified, considering Cox's second-order theory as the converging theory without wall effects. From low to intermediate confinements, the new Cox-Shapira-Haber model fitted the observed experimental deformations

  19. Fuzzy-Neural Control of Hot-Rolling Mill

    Khearia Mohamad

    2010-12-01

    Full Text Available This paper deals with the application of Fuzzy-Neural Networks (FNNs in multi-machine system control applied on hot steel rolling. The electrical drives that used in rolling system are a set of three-phase induction motors (IM controlled by indirect field-oriented control (IFO. The fundamental goal of this type of control is to eliminate the coupling influence though the coordinate transformation in order to make the AC motor behaves like a separately excited DC motor. Then use Fuzzy-Neural Network in control the IM speed and the rolling plant. In this work MATLAB/SIMULINK models are proposed and implemented for the entire structures. Simulation results are presented to verify the effectiveness of the proposed control schemes. It is found that the proposed system is robust in that it eliminates the disturbances considerably.

  20. SELF-ALIGNING EVEN LOAD MECHANISM OF MULTI-ROW BEARINGS OF LARGE STRIP ROLLING MILL

    HUANG Qingxue; LI Yugui; SHEN Guangxian; CHEN Zhanfu; SHU Xuedao; SHI Rong; ZHAO Hongwei; CHEN Buquan

    2006-01-01

    The load distribution of multi-row bearings of large strip rolling mill is fully analyzed by3D contact boundary element method (BEM). It is found out that bearings are frequently worn out due to serious uneven load on the multi-row rollers. The constraint mechanism of the previous rolling system is found to be unreasonable by theoretical analysis on heavy machinery structure. A mechanism of self-aligning even load for workroll bearing of 2 050 mm hot rolling mill of Baoshan I&S Co. is developed. This device is manufactured with particular regard to the structure of 2 050 mm hot rolling mill mentioned above. Hence, uneven load on multi-row bearings is greatly relieved and their lives are remarkably prolonged. Meanwhile, theoretical analysis and on-spot tests prove the rationality and validity of the device.

  1. Application of simulated annealing algorithm to improve work roll wear model in plate mills

    2002-01-01

    Employing Simulated Annealing Algorithm (SAA) and many measured data, a calculation model of work roll wear was built in the 2 800 mm 4-high mill of Wuhan Iron and Steel (Group) Co.(WISCO). The model was a semi-theory practical formula. Its pattern and magnitude were still hardly defined with classical optimization methods. But the problem could be resolved by SAA. It was pretty high precision to predict the values for the wear profiles of work roll in a rolling unit. Afterone-year application, the results show that the model is feasible in engineering, and it can be applied to predict the wear profiles of work roll in other mills

  2. Metal rolling - Asymmetrical rolling process

    Alexa, V.; Raţiu, S.; Kiss, I.

    2016-02-01

    The development of theory and practice related to the asymmetric longitudinal rolling process is based on the general theory of metalworking by pressure and symmetric rolling theory, to which a large number of scientists brought their contribution. The rolling of metal materials was a serious problem throughout history, either economically or technically, because the plating technologies enabled the consumption of raw materials (scarce and expensive) to be reduced, while improving the mechanical properties. Knowing the force parameters related to asymmetric rolling leads to the optimization of energy and raw material consumption. This paper presents data on symmetric rolling process, in order to comparatively highlight the particularities of the asymmetric process.

  3. Prediction of Rolling Load in Hot Strip Mill by Innovations Feedback Neural Networks

    ZHANG Li-yong; WANG Jun; MA Fu-ting

    2007-01-01

    Because the structure of the classical mathematical model of rolling load is simple, even with the self-adapting technology, it is difficult to accommodate the increasing dimensional accuracy. Motivated by this fact, an Innovations Feedback Neural Networks (IFNN) was presented based on the idea of Kalman prediction. The neural networks used the Back Propagation (BP) algorithm and applied it to the prediction of rolling load in hot strip mill. The theoretical results and the off-line simulation show that the prediction capability of IFNN is better than that of normal BP networks, namely, for the prediction of the rolling load in hot strip mill, the prediction precision of IFNN is higher than that of normal BP networks. Finally, a relative complete rolling load prediction system was developed on Windows 2003/XP platform using the OOP programming method and the SQL server2000 database. With this system, the rolling load of a 1700 strip mill was calculated, and the prediction results obtained correspond well with the field data. It shows that IFNN is valid for rolling load prediction.

  4. Axial Rolling Unit on the Vertical Ring Rolling Mill%立式辗环机的轴向辗压装置

    江绍成

    2011-01-01

    Up to now, the vertical ring rolling mills in China and overseas has no axial rolling unit because of multi-reasons. So side burr and inertia quality problem on the end hollow of rings produced by vertical ring rolling mill haven't been solved. A new kind of axial rolling unit which suits the vertical ring rolling mill had been designed and manufactured. Comparing with axial rolling unit in the horizontal ring rolling mill, this unit is simple in structure and easy in installation with convenient adjustment.%目前国内外的立武辗环机由于多种原因都没有设置轴向辗压装置.因此,无法解决立式辗环机的环件的侧面毛刺和端面凹陷的惯性质量问题.为此,设计制造了一种适合于立式辗环机的新型轴向辗压装置,它不同于卧式辗环机轴向辗压装置的庞大和复杂,其结构简单实用、便于安装,且调整操作方便.

  5. Extended Kalman Filter Based Neural Networks Controller For Hot Strip Rolling mill

    The present paper deals with the application of an Extended Kalman filter based adaptive Neural-Network control scheme to improve the performance of a hot strip rolling mill. The suggested Neural Network model was implemented using Bayesian Evidence based training algorithm. The control input was estimated iteratively by an on-line extended Kalman filter updating scheme basing on the inversion of the learned neural networks model. The performance of the controller is evaluated using an accurate model estimated from real rolling mill input/output data, and the usefulness of the suggested method is proved

  6. Production of sponge iron powder by reduction of rolling mill scale

    Martín Hernández, María Isabel; López Gómez, Félix Antonio; Torralba Castelló, José Manuel

    2012-01-01

    Rolling mill scale is a solid by-product of the steelmaking industry that contains metallic iron (Fe) and three types of iron oxides: wustite (FeO), hematite (α-Fe2O3) and magnetite (Fe3O4). It also contains traces of non-ferrous metals, alkaline compounds and oils from the rolling process. A study is made of the reduction of mill scale to sponge iron using coke at different temperatures and times. The reduced samples are studied by X-ray diffraction (XRD) and scanning electron microscopy (SE...

  7. High Precision Prediction of Rolling Force Based on Fuzzy and Nerve Method for Cold Tandem Mill

    JIA Chun-yu; SHAN Xiu-ying; NIU Zhao-ping

    2008-01-01

    The rolling force model for cold tandem mill was put forward by using the Elman dynamic recursive network method, based on the actual measured data. Furthermore, a good assumption is put forward, which brings a full universe of discourse self-adjusting factor fuzzy control, closed-loop adjusting, based on error feedback and expertise into a rolling force prediction model, to modify prediction outputs and improve prediction precision and robustness. The simulated results indicate that the method is highly effective and the prediction precision is better than that of the traditional method. Predicted relative error is less than ±4%, so the prediction is high precise for the cold tandem mill.

  8. Advanced Soft Sensor Technology to be Used for Cold Rolling Mills

    Ettler, P.; Dedecius, Kamil; Juričič, D.; Preglej, A.

    Toulouse : IEEE, 2011, s. 1-4. ISBN 978-1-4577-0016-3. [16th IEEE International Conference on Emerging Technologies and Factory Automation ETFA'2011. Toulouse (FR), 05.09.2011-09.09.2011] R&D Projects: GA MŠk(CZ) 7D09008 Institutional research plan: CEZ:AV0Z10750506 Keywords : soft sensor * rolling mill Subject RIV: IN - Informatics, Computer Science http://library.utia.cas.cz/separaty/2011/AS/dedecius-advanced soft sensor technology to be used for cold rolling mills.pdf

  9. Rolling Reloaded

    Jones, Simon A.; Nieminen, John M.

    2008-01-01

    Not so long ago a new observation about rolling motion was described: for a rolling wheel, there is a set of points with instantaneous velocities directed at or away from the centre of the wheel; these points form a circle whose diameter connects the centre of the wheel to the wheel's point of contact with the ground (Sharma 1996 "Eur. J. Phys."…

  10. Diagnosis of Gearbox Typical Fault in Rolling Mills Based on the Wavelet Packets Technology

    CUI Lingli; GAO Lixin; ZHANG Jianyu; DING Fang

    2006-01-01

    The early impulse fault diagnosis of the gearbox in rolling mills is often difficult and labour intensive because the gearbox of that high speed machine is multi-shafting transmission system, in which many gearsets and rolling bears work together at the same time and there are much complex frequency structure and various disturb. A new time-frequency method based on the wavelet packets technique was developed and used to extract the impact feature from signals collected from faulty data of one rolling mills gearbox. The method improves the signal to noise ration so that results obtained using this method represents features with fine resolution in both low-frequency and the high frequency bands. The results of analysis indicate the validity and the practicability of the method proposed here.

  11. Soft Starting Arrangements Availables for Hot Rolling Mills for Energy Conservation

    Bisen, A. M.; Bapat, P. M.; Gagnuly, S. K.

    2012-07-01

    The conventional rolling mills in India are producing a major part of structural steel requirement of the country. The energy conservation in these rolling mills can be achieved mainly by reducing the size of the prime mover i.e. main electric motor. The power consumption per ton can be considerably decreased through proper selection of electric motor since it has been an observation by many surveyors[1] that the selection of electric motor of the rolling mill has been almost five to ten times on the higher side which can be easily verified from the power consumption and motor working data.Flywheel is a mechanical storage device. Largest size of flywheels are frequently recommended for smooth running of rolling mills. The main difficulty encountered in selecting large capacity flywheel or flywheel gear box system is the starting of the mill with smaller capacity electric motor. The starting characteristic of electric motor is not suitable for starting such rolling mill with very high inertia flywheel. In such condition it becomes very essential to introduce the soft starting arrangement for the electric motor so that considerably small size motor can start the flywheel effectively.Soft starters are used for the smooth start-up control of three-phase induction motors. The soft starter is functionally located between the Flywheel and the electric motor. In selecting the correct soft starter to suit the application the peculiarities of the soft start should be considered. In the prevailing conditions we use the motor of high horse power due to the fact that the flywheel requires high torque to be driven initially. For the same reason the efficiency of the flywheel is very low initially. Once the flywheel stores sufficient power which is required at the start up, the flywheel then requires less power than given initially. If we somehow are able to increase the efficiency of the flywheel using a flexible electrical, mechanical, hydraulic or flexible drives with

  12. Influence of the Radiation Shield on the Temperature of Rails Rolled in the Reversing Mill

    Gołdasz A.

    2015-04-01

    Full Text Available The paper presents a mathematical model of heat transfer during cooling of hot-rolled rails in the reversing mill. The influence of the radiation shield on the temperature of rolled rails has been analyzed. The heat transfer model for cooling a strip covered by the thermal shield has been presented. The two types of shields build of steel and aluminum sheets separated with insulating layer have been studded. Calculations have been performed with self developed software which utilizes the finite element method.

  13. An investigation of worn work roll materials used in the finishing stands of the hot strip mill for steel rolling

    Nilsson, Maria; Olsson, Mikael

    2013-01-01

    The surface failure characteristics of different work roll materials, i.e. high speedsteel, high chromium iron and indefinite chill iron, used in the finishing stands of a hot stripmill have been investigated using stereomicroscopy, three-dimensional optical profilometry, scanning electron microscopy and energy-dispersive X-ray spectroscopy. The results show that the surface failure mechanisms of work rolls for hot rolling are very complex, involving plastic deformation, abrasive wear, adhesi...

  14. Assessment of personal noise exposure of overhead-traveling crane drivers in steel-rolling mills

    ZENG Lin; CHAI Dong-liang; LI Hui-juan; LEI Zhuo; ZHAO Yi-ming

    2007-01-01

    Background Noise is widespread occupational hazard in iron and steel industry. Overhead-traveling cranes are widely used in this industry, but few studies characterized the overhead-traveling crane drivers' noise exposure level so far. In this study, we assessed and characterized personal noise exposure levels of overhead-traveling crane drivers in two steel-rolling mills.Methods One hundred and twenty-four overhead-traveling crane drivers, 76 in the cold steel-rolling mill and 48 in the hot steel-rolling mill, were enrolled in the study. Personal noise dosimeters (AIHUA Instruments Model AWA5610e,Hangzhou, China) were used to collect full-shift noise exposure data from all the participants. Crane drivers carried dosimeters with microphones placed near their collars during the work shifts. Work logs had been taken by the drivers simultaneously. Personal noise exposure data were divided into segments based on lines in which they worked. All statistical analyses were done using SPSS 13.0.Results The average personal noise exposure (LAeq.8h) of overhead-traveling crane drivers in the hot steel-rolling mills ((85.03±2.25) dB(A)) was higher than that in the cold one ((83.05±2.93) dB(A), P<0.001). There were 17 overhead traveling cranes in the hot steel-rolling mill and 24 cranes in the cold one, of which carrying capacities varied from 15 tons to 100 tons. The average noise exposure level based on different lines in the hot and cold steel-rolling mills were (85.2±2.61) dB(A) and (83.3±3.10) dB(A) respectively (P=0.001), which were similar to the average personal noise exposure in both mills. The noise exposure levels were different among different lines (P=0.021).Conclusion Noise exposure levels, depending upon background noise levels and the noise levels on the ground, are inconstant. As the noise exposure levels are above the 85 dB(A) criteria, these drivers should be involved in the Hearing Conservation Program to protect their hearing.

  15. Kulturens rolle

    Hasse, Cathrine

    Kulturens rolle. Herunder kulturens betydning for psykologisk teori og forskning set i lyset af den stigende globalisering og væksten i kulturmøder. Der gives eksempler fra hverdagssituationer, den pædagogiske praksis, fra indvandrerforskning, turister men også fra avisernes referater af kulturmø......Kulturens rolle. Herunder kulturens betydning for psykologisk teori og forskning set i lyset af den stigende globalisering og væksten i kulturmøder. Der gives eksempler fra hverdagssituationer, den pædagogiske praksis, fra indvandrerforskning, turister men også fra avisernes referater af...

  16. Online Prediction under Model Uncertainty Via Dynamic Model Averaging: Application to a Cold Rolling Mill

    Raftery, A. E.; Kárný, Miroslav; Ettler, P.

    Volume 52, Number 1 (2010), s. 52-66. ISSN 0040-1706 R&D Projects: GA MŠk 1M0572; GA MŠk(CZ) 7D09008 Institutional research plan: CEZ:AV0Z10750506 Keywords : prediction * rolling mills * Bayesian Dynamic Averaging Subject RIV: BC - Control Systems Theory Impact factor: 1.560, year: 2010 http://library.utia.cas.cz/separaty/2010/AS/karny-0342595.pdf

  17. Control of grinding the mandrel working surface of cold-rolling mills

    Петраков, Юрій Володимирович; Чамата, Сергій Миколайович

    2015-01-01

    It was found that for maximum performance of grinding the mandrel working surface of cold rolling mills at fulfilling all quality requirements for the machined surface, a graph of the material removal rate (MaterialRemovalRate) throughout the grinding cycle must be located in the region of acceptability, which is limited by the marginal algorithm as close to the boundaries of this region as possible. A problem of determining the material removal rate in grinding the curved surface of the mand...

  18. Effect of Stiffness of Rolling Joints on the Dynamic Characteristic of Ball Screw Feed Systems in a Milling Machine

    Dazhong Wang; Yan Lu; Tongchao Zhang; Keyong Wang; Akira Rinoshika

    2015-01-01

    Dynamic characteristic of ball screw feed system in a milling machine is studied numerically in this work. In order to avoid the difficulty in determining the stiffness of rolling joints theoretically, a dynamic modeling method for analyzing the feed system is discussed, and a stiffness calculation method of the rolling joints is proposed based on the Hertz contact theory. Taking a 3-axis computer numerical control (CNC) milling machine set ermined as a research object, the stiffness of its f...

  19. Heavy metals adsorption on rolling mill scale; Adsorcion de metales pesados sobre cascarill de laminacion

    Lopez, F. A.; Martin, M. I.; Perez, C.; Lopez-Delgado, A.; Alguacil, E. J.

    2003-07-01

    A great quantity of industries are responsible for contaminating the environment with the heavy metals which are containing in their wastewaters. The recovery of these metals is both from an environmental and economical points of view of the upmost interest. A study is made of the use of mill scale-originating in the hot rolling of steel-as an adsorbent for the removal of heavy metals from liquid effluents. The adsorption of Zn''2+, Cd''2+ y Pb''2+ on the rolling mill scale was investigated by determination of adsorption isotherms. The effect of time, equilibrium temperature and concentration of metal solution on mill scale adsorption efficiency was evaluated. The adsorption process was analysed using the theories of Langmuir and Freundlich. Desorption process of metals from loaded mill scales was also studied using several doser bent at different experimental conditions. It has been proved that the mill scale is an effective adsorbent for the cations studies in aqueous solutions within the range of the working concentrations. (Author) 32 refs.

  20. Effect of powder milling on mechanical properties of hot-pressed and hot-rolled Cu–Cr–Nb alloy

    Highlights: •Milled powder enhances sintering and mechanical properties after hot pressing. •Hot-rolling of hot-pressed samples made from milled powder enhances ductility. •Pore size and number of pores decreases after hot-rolling. -- Abstract: The present study is on the effect of mechanical milling of gas-atomized powders on mechanical properties of the hot-pressed and subsequently hot-rolled Cu–8 at% Cr–4 at% Nb alloy with a microstructure consisting of pure copper matrix hardened by intermetallic Cr2Nb precipitates. The mechanically milled powders result in lower sintering temperature during hot pressing compared to the atomized powders. The hot-pressed samples made from the milled powder exhibit significantly higher hardness and tensile strength, but lower ductility and electrical conductivity compared to that made from the un-milled gas-atomized powders. The hot rolling results in marginal increase in strength, but significant increase in ductility compared to the hot-pressed alloy for both the milled and atomized powders and it is attributed to the decrease in size of the pores and amount of porosities after hot rolling

  1. Development of Centrifugal Cast High Speed Steel Roll with High Wear Resistance for Pre-Finishing Stands of a Hot Rod-Wire Mill

    JIANG Zhi-qiang; FENG Xi-lan; FU Han-guang; SHA Quan-you

    2004-01-01

    The present study aims at developing high speed steel ( HSS ) as roll materials to replace traditional roll materials such as the alloy cast iron and powder metallurgical (PM) hard alloy, because lowcost alley cast iron rolls have poor wear resistance and the cost of high-quality PM hard alloy rolls is too high to be accepted by some users. By means of a centrifugal casting method, HSS rolls with excellent wear resistance have been developed. Its hardness is 65 ~ 67HRC, and its variation is smaller than 2HRC ; its impact toughness excels 15J/cm2. Using pre-finishing stands of a high-speed hot wire-rod rolling mill, the wear raze of HSS rolls per one thousand ton of steel is 0. 25mm. However, the manufacturing burden of HSS rolls is obviously lower than that of PM hard alloy rolls; it is only 30% of that of PM hard alloy rolls.

  2. Increasing efficiency of cold rolling of corrosion resistant steel at mismatching roll velocities

    On the example of 12Kh18N10T steel rolling it is shown that 7-10% mismatching roll velocities raise the rolling efficiency, increase productivity and technological abilities of four-high mills at production of cold-rolled sheets. Scheme of the system of roll velocities mismatching control at asymmetrical rolling is presented. The comparative conditions of symmetrical and asymmetrical rolling of 0.8 x 1030 mm sheets from 12Kh18N10T steel are given

  3. Steel strip quality upgrading through optimization of cold rolling schedules in continuous mills

    Garber; E.; Kozhevnikova; I.; Ganichev; P.; Ivoditov; V.; Traino; A.; Kuznetsov; V.

    2005-01-01

    As a result of research into the cold rolling theory and practice, a complex of mathematical models and model-based process solutions has been elaborated to improve quality of cold rolled steel strips and reduce energy consumption. The use of the above designs made it possible to establish a number of new regularities and employ them for cold rolling practice improvement and cold-rolled strip quality upgrading.

  4. Failure analysis of work rolls of a thin hot strip mill

    Piyas Palit

    2015-04-01

    Destructive testing (including metallography and chemical analysis was carried out on the failed roll samples in the first case and gross abnormality in microstructure was observed. Some foreign particle/entrapment was observed after dressing of the working surface of roll at 566 mm diameter (initial diameter of roll was 620 mm and scrap diameter was projected to be 540 mm. The chemical composition of the particle was analyzed by a portable X-Ray Fluorescence (XRF alloy analyzer and it was confirmed that the particle is basically a ferroalloy which was entrapped in the shell of the roll, probably during casting/manufacturing of roll.

  5. Thermal fatigue of high chromium steel rolls

    Valverde Montraveta, Gerard

    2013-01-01

    Within the master work the phenomenon of appearance of firecracks on the surface of the work rolls that occur during hot rolling of flat products in the case of regular rolling conditions and in the case of the rolling mill stalls was investigated. During hot rolling work rolls are subjected to successive heating and cooling conditions. Their surface is exposed to rapid temperature changes due to the contact with hot rolled material and due to cold water used for rolls cooling. These cyclic h...

  6. A Fault Diagnosis Expert System for a Heavy Motor Used in a Rolling Mill

    2002-01-01

    A fault diagnosis expert system for a heavy motor used in a rolling mill is established in this paper. The fault diagnosis knowledge base was built, and its knowledge was represented by production rules. The knowledge base includes daily inspection system, brief diagnosis system and precise diagnosis system. A pull-down menu was adopted for the management of the knowledge base. The system can run under the help of expert system development tools. Practical examples show that the expert system can diagnose faults rapidly and precisely.

  7. Simulation of two Stands Cold Rolling Mill Process Using a Combination of Neural Networks and Genetic Algorithms to Avoid the Chatter Phenomenon

    Behzad BahramiNejad; Sayed Ali Mousavi; Mehrdad Dehghani

    2015-01-01

    Rolling mill Industry is one of the most profitable industries in the world. Chatter phenomenon is one of the key issues in this industry. Chatter or rolling unwanted vibrations not only has an adverse effect on product quality, but also reduces considerably the efficiency with reduced rolling velocities of rolling lines. This paper is an attempt to simulate the phenomenon of Chatter more accurate than the previous performed simulations. In order to increase the production speed, it needs to ...

  8. Investigation of the influence of the chemical composition of HSLA steel grades on the microstructure homogeneity during hot rolling in continuous rolling mills using a fast layer model

    Schmidtchen, M.; Rimnac, A.; Warczok, P.; Kozeschnik, E.; Bernhard, C.; Bragin, S.; Kawalla, R.; Linzer, B.

    2016-03-01

    The newly developed LaySiMS simulation tool provides new insight for inhomogeneous material flow and microstructure evolution in an endless strip production (ESP) plant. A deepened understanding of the influence of inhomogeneities in initial material state, temperature profile and material flow and their impact on the finished product can be reached e.g. by allowing for variable layer thickness distributions in the roll gap. Coupling temperature, deformation work and work hardening/recrystallization phenomena accounts for covering important effects in the roll gap. The underlying concept of the LaySiMS approach will be outlined and new insight gained regarding microstructural evolution, shear and inhomogeneous stress and strain states in the roll gap as well as local residual stresses will be presented. For the case of thin slab casting and direct rolling (TSDR) the interrelation of inhomogeneous initial state, micro structure evolution and dissolution state of micro alloying elements within the roughing section of an ESP line will be discussed. Special emphasis is put on the influence of the local chemical composition arising from direct charging on throughthickness homogeneity of the final product. It is concluded that, due to the specific combination of large reductions in the high reduction mills (HRM) and the highly inhomogeneous inverse temperature profile, the ESP-concept provides great opportunities for homogenizing the microstructure across the strip thickness.

  9. Simulation of accelerated strip cooling on the hot rolling mill run-out roller table

    Full text: A mathematical model of the thermal state of the metal on the run-out roller table of a continuous wide hot-strip mill is presented. The mathematical model takes into account the heat generation during the polymorphic γ → α transformation of super cooled austenite phase and the influence of chemical composition on the physical properties of the steel. The model allows the calculation of modes of accelerated cooling of strips on the run-out roller table of a continuous wide hot strip mill. Winding temperature calculation error does not exceed 20 °C for 98.5 % of the strips from low-carbon and low-alloyed steels. key words: hot rolled, wide-strip, accelerated cooling, run-out roller table, polymorphic transformation, mathematical modeling

  10. Cross Shear Roll Bonding

    Bay, Niels; Bjerregaard, Henrik; Petersen, Søren. B;

    1994-01-01

    The present paper describes an investigation of roll bonding an AlZn alloy to mild steel. Application of cross shear roll bonding, where the two equal sized rolls run with different peripheral speed, is shown to give better bond strength than conventional roll bonding. Improvements of up to 20......-23% in bond strength are found and full bond strength is obtained at a reduction of 50% whereas 65% is required in case of conventional roll bonding. Pseudo cross shear roll bonding, where the cross shear effect is obtained by running two equal sized rolls with different speed, gives the same results....

  11. Wedge - rolls rolling of hollowed parts

    Z. Pater

    2006-08-01

    Full Text Available Purpose: Presentation of the possibilities of application of a new manufacturing method, called wedge rollsrolling (WRR in forming of axi – symmetrical hollowed parts.Design/methodology/approach: The research work was done in a specially designed laboratory rolling millLUW-2. During the research, hollowed parts from steel were rolled in hot forming conditions. Basic kinematicaland force parameters of the process were noticed during rolling.Findings: On the basis of the conducted research it was stated that the WRR method could be used for formingof hollowed parts with the precision compared with the precision obtained in the typical cross wedge rollingprocesses (CWR. At the same time, it was proved that this method could be used for rolling from billets withthe wall thinner than the wall given in the CWR.Research limitations/implications: The research were limited to the wedges with spreading angles withinrange of β = (5° ÷ 9°, with the constant values of forming angle α = 30° and relative reduction ratio δ = 1.45.In the future, it is planned to analyse the influence of changes of angle α and relative reduction ratio δ on theWRR process.Practical implications: The conducted research can be used for designing of a new industrial method of metalforming of hollowed parts.Originality/value: The innovation of this solution is based on the application of only one wedge for forming.Because of that, the WRR method is cheaper for implementation than used so far CWR processes. This methodcan be applied mainly in automotive and aviation industries.

  12. Gradient structure produced by three roll planetary milling: Numerical simulation and microstructural observations

    In this study a gradient grain structure was produced by processing rod billets through three roll planetary milling (also known as PSW process). This kind of gradient structure is reported to provide an excellent combination of strength and ductility owing to an ultrafine-grained surface layer and a coarse-grained interior of the billet. Specifically, copper rod samples were subjected to up to six passes of PSW at room temperature. To study the evolution of the microstructure during the deformation, microhardness measurements and Electron Backscatter Diffraction (EBSD) analysis were performed after one, three and six passes. Additionally, the distributions of the equivalent stress during PSW and the equivalent strain after processing were studied by finite element analysis using the commercial software QFORM. The results showed the efficacy of PSW as a means of imparting a gradient ultrafine-grained structure to copper rods. A good correlation between the simulated equivalent strain distribution and the measured microhardness distribution was demonstrated

  13. New technology for recycling materials from oily cold rolling mill sludge

    Bo Liu; Shen-gen Zhang; Jian-jun Tian; De-an Pan; Ling Meng; Yang Liu

    2013-01-01

    Oily cold rolling mill (CRM) sludge is one of metallurgical industry solid wastes. The recycle of these wastes can not only protect the environment but also permit their reutilization. In this research, a new process of“hydrometallurgical treatment+hydrothermal synthesis”was investigated for the combined recovery of iron and organic materials from oily CRM sludge. Hydrometallurgical treatment, mainly including acid leaching, centrifugal separation, neutralization reaction, oxidizing, and preparation of hydrothermal reaction precursor, was first utilized for processing the sludge. Then, micaceous iron oxide (MIO) pigment powders were prepared through hydrothermal reaction of the obtained precursor in alkaline media. The separated organic materials can be used for fuel or chemical feedstock. The quality of the prepared MIO pigments is in accordance with the standards of MIO pigments for paints (ISO 10601-2007). This clean, eff ective, and economical technology off ers a new way to recycle oily CRM sludge.

  14. Gradient structure produced by three roll planetary milling: Numerical simulation and microstructural observations

    Li Wang, Ya [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Center for Advanced Hybrid Materials, Department of Materials Engineering, Monash University, Clayton, Victoria 3800 (Australia); Molotnikov, Andrey [Center for Advanced Hybrid Materials, Department of Materials Engineering, Monash University, Clayton, Victoria 3800 (Australia); Diez, Mathilde [Department of Materials Science and Engineering, Seoul National University, 151-742 (Korea, Republic of); Lapovok, Rimma [Center for Advanced Hybrid Materials, Department of Materials Engineering, Monash University, Clayton, Victoria 3800 (Australia); Kim, Hyoun-Ee [Department of Materials Science and Engineering, Seoul National University, 151-742 (Korea, Republic of); Tao Wang, Jing, E-mail: jtwang@njust.edu.cn [School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094 (China); Estrin, Yuri, E-mail: yuri.estrin@monash.edu [Center for Advanced Hybrid Materials, Department of Materials Engineering, Monash University, Clayton, Victoria 3800 (Australia); Laboratory of Hybrid Nanostructured Materials, NITU MISIS, Leninskii prospect 4, Moscow 119049 (Russian Federation)

    2015-07-15

    In this study a gradient grain structure was produced by processing rod billets through three roll planetary milling (also known as PSW process). This kind of gradient structure is reported to provide an excellent combination of strength and ductility owing to an ultrafine-grained surface layer and a coarse-grained interior of the billet. Specifically, copper rod samples were subjected to up to six passes of PSW at room temperature. To study the evolution of the microstructure during the deformation, microhardness measurements and Electron Backscatter Diffraction (EBSD) analysis were performed after one, three and six passes. Additionally, the distributions of the equivalent stress during PSW and the equivalent strain after processing were studied by finite element analysis using the commercial software QFORM. The results showed the efficacy of PSW as a means of imparting a gradient ultrafine-grained structure to copper rods. A good correlation between the simulated equivalent strain distribution and the measured microhardness distribution was demonstrated.

  15. Effect of Stiffness of Rolling Joints on the Dynamic Characteristic of Ball Screw Feed Systems in a Milling Machine

    Dazhong Wang

    2015-01-01

    Full Text Available Dynamic characteristic of ball screw feed system in a milling machine is studied numerically in this work. In order to avoid the difficulty in determining the stiffness of rolling joints theoretically, a dynamic modeling method for analyzing the feed system is discussed, and a stiffness calculation method of the rolling joints is proposed based on the Hertz contact theory. Taking a 3-axis computer numerical control (CNC milling machine set ermined as a research object, the stiffness of its fixed joint between the column and the body together with the stiffness parameters of the rolling joints is evaluated according to the Takashi Yoshimura method. Then, a finite element (FE model is established for the machine tool. The correctness of the FE model and the stiffness calculation method of the rolling joints are validated by theoretical and experimental modal analysis results of the machine tool’s workbench. Under the two modeling methods of joints incorporating the stiffness parameters and rigid connection, a theoretical modal analysis is conducted for the CNC milling machine. The natural frequencies and modal shapes reveal that the joints’ dynamic characteristic has an important influence on the dynamic performance of a whole machine tool, especially for the case with natural frequency and higher modes.

  16. Increasing efficiency of cold rolling of corrosion resistant steel at mismatching roll velocities. [12Kh18N10T steel

    Agishev, L.A.; Grishkov, A.I.; Fisher, A.R.; Frolov, G.I.; Kolesnikov, N.A. (Tsentral' nyj Nauchno-Issledovatel' skij Inst. Chernoj Metallurgii, Moscow (USSR))

    1983-01-01

    On the example of 12Kh18N10T steel rolling it is shown that 7-10% mismatching roll velocities raise the rolling efficiency, increase productivity and technological abilities of four-high mills at production of cold-rolled sheets. Scheme of the system of roll velocities mismatching control at asymmetrical rolling is presented. The comparative conditions of symmetrical and asymmetrical rolling of 0.8 x 1030 mm sheets from 12Kh18N10T steel are given.

  17. Simulation of two Stands Cold Rolling Mill Process Using a Combination of Neural Networks and Genetic Algorithms to Avoid the Chatter Phenomenon

    Behzad BahramiNejad

    2015-03-01

    Full Text Available Rolling mill Industry is one of the most profitable industries in the world. Chatter phenomenon is one of the key issues in this industry. Chatter or rolling unwanted vibrations not only has an adverse effect on product quality, but also reduces considerably the efficiency with reduced rolling velocities of rolling lines. This paper is an attempt to simulate the phenomenon of Chatter more accurate than the previous performed simulations. In order to increase the production speed, it needs to avoid parameters which effect on the Chatter and varieties with the rolling lines condition. Actual values of these parameters were determined in the archives of the Mobarakeh two stand cold rolling mills and collected on the 210 case study of real chattering. To simulate the experiment, a neural network is trained and weights and bias values of the neural network with genetic optimization algorithm were used to get an optimal neural network which reduces bugs on the test data. So this model is capable to predict speed of Chatter threshold on rolling process of two stand cold rolling mill with the accuracy less than one percent. So it can be used in rolling process with the building intelligent recognition systems to prevent the creator conditions of the chatter frequency range.

  18. INFLUENCE OF CONFIGURATION OF EQUIPMENT OF A HIGH-SPEED ROD MILL ON QUALITATIVE CHARACTERISTICS OF HIGH-CARBON ROLLED WIRE

    V. A. Lutsenko

    2015-11-01

    Full Text Available The quality of output production has increased in the result of new arrangement of finishing train of block construction of rod mill of RUP «BMZ». Additional using in rolled line of reducing-sizing block at production of high- carbon rolled wire enabled to reduce the dispersion of mechanical characteristics, to decrease the depth of decarburized layer.

  19. HOT ROLLING OF A FERRITIC STAINLESS STEEL IN A STECKEL MILL: THERMOMECHANICAL AND MICROSTRUCTURAL CARACTERIZATION AND MATHEMATICAL MODELLING OF THE EVOLUTION OF RECRYSTALLIZED VOLUME FRACTION OF FERRITE

    Willy Schuwarten Júnior

    2013-10-01

    Full Text Available A thermomechanical and a microstructure caracterization and a mathematical model of the evolution of the recrystallized volume fraction of ferrite in hot rolling in a Steckel mill have been carried out here. The proposed model is able to reasonably predict the observed in hot rolling, that is, there is 100% recrystallization of ferrite after roughing and partial recrystallization only after finishing

  20. HOT ROLLING OF A FERRITIC STAINLESS STEEL IN A STECKEL MILL: THERMOMECHANICAL AND MICROSTRUCTURAL CARACTERIZATION AND MATHEMATICAL MODELLING OF THE EVOLUTION OF RECRYSTALLIZED VOLUME FRACTION OF FERRITE

    Willy Schuwarten Júnior; Ronaldo Antônio Neves Marques Barbosa

    2013-01-01

    A thermomechanical and a microstructure caracterization and a mathematical model of the evolution of the recrystallized volume fraction of ferrite in hot rolling in a Steckel mill have been carried out here. The proposed model is able to reasonably predict the observed in hot rolling, that is, there is 100% recrystallization of ferrite after roughing and partial recrystallization only after finishing

  1. Rheology of coal-water slurries prepared by the high-pressure roll mill grinding of coal. Final report

    Fuerstenau, D.W.; De, A.

    1996-08-01

    The preparation of coal water slurries to replace fuel oil for direct combustion has become an important field in modem coal technology. The U.S. Department of Energy has planned or has underway several demonstration projects to burn coal-water slurries to replace fuel oil is attractive not only because there is an assured domestic supply of coal, but also on various technoeconomic grounds. Coal-water slurries combine the handling flexibility of fuel oil in power plants and various other industrial applications. This report discusses the rheology of coal-water slurries and the correlation to the coal preparation by grinding with a choke-fed high pressure roll mill. Performance of the roll mills and energy consumption are described.

  2. Finger milling-cutter CNC generating hypoid pinion tooth surfaces based on modified-roll method and machining simulation

    Li, Genggeng; Deng, Xiaozhong; Wei, Bingyang; Lei, Baozhen

    2011-05-01

    The two coordinate systems of cradle-type hypoid generator and free-form CNC machine tool by application disc milling-cutter to generate hypoid pinion tooth surfaces based on the modified-roll method were set up, respectively, and transformation principle and method for machine-tool settings between the two coordinate systems was studied. It was presented that finger milling-cutter was mounted on imagined disc milling-cutter and its motion was controlled directly by CNC shafts to replace disc milling-cutter blades effective cutting motion. Finger milling-cutter generation accomplished by ordered circular interpolation was determined, and interpolation center, starting and ending were worked out. Finally, a hypoid pinion was virtually machined by using CNC machining simulation software VERICUT.

  3. Three-Dimensional Model for Strip Hot Rolling

    ZHANG Guo-min; XIAO Hong; WANG Chun-hua

    2006-01-01

    A three-dimensional model for strip hot rolling was developed, in which the plastic deformation of strip, the thermal crown of rolls, roll deflection and flattening were calculated by rigid-plastic finite element method, finite difference method, influential function method and elastic finite element method respectively. The roll wear was taken into consideration. The model can provide detailed information such as rolling pressure distribution, contact pressure distribution between backup rolls and work rolls, deflection and flattening of work rolls, lateral distribution of strip thickness, and lateral distribution of front and back tensions. The finish rolling on a 1 450 mm hot strip mill was simulated.

  4. Genetic based sensorless hybrid intelligent controller for strip loop formation control between inter-stands in hot steel rolling mills.

    Thangavel, S; Palanisamy, V; Duraiswamy, K

    2008-04-01

    Safe operating environment is essential for all complex industrial processes. The safety issues in steel rolling mill when the hot strip passes through consecutive mill stands have been considered in this paper. Formation of sag in strip is a common problem in the rolling process. The excessive sag can lead to scrap runs and damage to machinery. Conventional controllers for mill actuation system are based on a rolling model. The factors like rise in temperature, aging, wear and tear are not taken into account while designing a conventional controller. Therefore, the conventional controller cannot yield a requisite controlled output. In this paper, a new Genetic-neuro-fuzzy hybrid controller without tension sensor has been proposed to optimize the quantum of excessive sag and reduce it. The performance of the proposed controller has been compared with the performance of fuzzy logic controller, Neuro-fuzzy controller and conventional controller with the help of data collected from the plant. The simulation results depict that the proposed controller has superior performance than the other controllers. PMID:18093589

  5. Evaluation of Health Consequences of Air Pollution Induced by Beam Rolling Mills Factory (Iran

    Rafiei Masoud

    2014-10-01

    Full Text Available The increases in air pollution over the metropolitan cities are a threat to human health and environment. An attempt has been made to evaluate the health consequences of indoor air pollution induced by Beam Rolling Mills Factory at Ahwaz (Iran. A questionnaire was prepared to obtain information on health of 481 workers, out of which 200 each were selected from exposed and non-exposed category by stratified randomized method. Fisher exact test and chi-square test were used to calculate the values. The study concludes that more than 80% of the workers have high exposure risk to diseases. Analysis of the health impacts reveals that exposed workers are more prone to various diseases as compared to the non-exposed workers. It is also observed that exposure to air pollutants might be the causative factor for various diseases among the smokers but also nonsmoking workers. The analysis also reveals that there is higher relative risk in occupational fatigue and cardio-vascular disease. Further, the study found that percentage of workers having various diseases is much higher in the indoor environment as compared to the outdoor environment

  6. Transverse Crack Modeling of Continuously Casted Slabs through Finite Element Method in Roughing Rolling at Wide Strip Mill

    Pesin, A.; Salganik, V.; Pustovoytov, D.

    2010-06-01

    In the pipe billet production at the wide strip mills of hot rolling big metal losses are caused by surface defects that affect most parts of the finished strips. The rolling surface defects are referred to the breach of steelmaking technology. Specialists mostly face defects of metal surface such as "scab" and "crack". The only area suffered from these defects is a slab edge. This area has the least surface temperature at the unbending of the continuous-casting machine, and together with deep buckles made by reciprocating motion of the crystallizer it is mostly subjected to transverse cracks that can be up to several millimeters. Each surface defect of the continuously casted slab will further turn into the surface defect of the strip bar. For some grade sets, mostly made of pipe steel grades the amount of strips with these defects can reach up to 60-70%. The area that is mostly prone to these defects is the edge of the strip. The work reveals investigation of the form change peculiarities in the transverse cracks of the continuously casted slab in roughing rolling in the horizontal rollers. The finite element method with software DEFORM 3D V6.1 has been applied in modeling. The work gives a form change mechanism of transverse cracks of slabs in deformation. Further crack growth in rolling is assessed due to Cockroft-Latham criteria.

  7. Rolling Shutter Motion Deblurring

    Su, Shuochen

    2015-06-07

    Although motion blur and rolling shutter deformations are closely coupled artifacts in images taken with CMOS image sensors, the two phenomena have so far mostly been treated separately, with deblurring algorithms being unable to handle rolling shutter wobble, and rolling shutter algo- rithms being incapable of dealing with motion blur. We propose an approach that delivers sharp and undis torted output given a single rolling shutter motion blurred image. The key to achieving this is a global modeling of the camera motion trajectory, which enables each scanline of the image to be deblurred with the corresponding motion segment. We show the results of the proposed framework through experiments on synthetic and real data.

  8. Catalytic surface modification of roll-milled poly(ε-caprolactone) biaxially stretched to ultra-thin dimension

    A novel roll-milling polymer processing technique along with biaxial stretching was used to fabricate 10 μm thick poly(ε-caprolactone) films. A less invasive collagen surface modification was used, involving a reaction between corona-preactivated membranes and ferrous-containing acrylic acid solution at the low temperature of 42 oC. Successful modified films were characterized by Toluidine Blue O assay and X-ray photoelectron spectroscopy. Human umbilical vein endothelial cells also showed both higher proliferation rate and differentiated cobblestone morphology on these collagen-immobilized substrates

  9. Catalytic surface modification of roll-milled poly({epsilon}-caprolactone) biaxially stretched to ultra-thin dimension

    Foo, H.L. [Graduate Programme in Bioengineering, National University of Singapore (Singapore); Bionic Materials Technology Group, Biomaterials Center, National Institute for Materials Science (Japan); Taniguchi, A. [Bionic Materials Technology Group, Biomaterials Center, National Institute for Materials Science (Japan); Yu, H. [Graduate Programme in Bioengineering, National University of Singapore (Singapore); Department of Physiology, National University of Singapore (Singapore); Okano, T. [Bionic Materials Technology Group, Biomaterials Center, National Institute for Materials Science (Japan); Institute of Biomedical Engineering, Tokyo Women' s Medical University (Japan); Teoh, S.H. [Graduate Programme in Bioengineering, National University of Singapore (Singapore) and Department of Mechanical Engineering, National University of Singapore (Singapore)]. E-mail: mpetsh@nus.edu.sg

    2007-03-15

    A novel roll-milling polymer processing technique along with biaxial stretching was used to fabricate 10 {mu}m thick poly({epsilon}-caprolactone) films. A less invasive collagen surface modification was used, involving a reaction between corona-preactivated membranes and ferrous-containing acrylic acid solution at the low temperature of 42 {sup o}C. Successful modified films were characterized by Toluidine Blue O assay and X-ray photoelectron spectroscopy. Human umbilical vein endothelial cells also showed both higher proliferation rate and differentiated cobblestone morphology on these collagen-immobilized substrates.

  10. Assessment of Air Pollution and its Effects on Health of Workers of Steel Re-Rolling Mills in Hyderabad

    Altaf Alam Noonari; Rasool Bux Mahar; Abdul Razaque Sahito

    2016-01-01

    The SRRMs (Steel Re-Rolling Mills) are being releasing air pollutants in the environment. In order to evaluate their effect on the health of the workers, health and safety issues were analyzed by first measuring the concentrations of SO x (OIxides of Sulphur), NO x (Oxides of Nitrogen), CO (Carbon Monoxide) and O2 (Oxygen) produced in the three SRRMs located in SITE area Hyderabad. The mean concentration of SO x , NO x and CO were in the order of 0.35, 0.280, 6.333 ppm, respectively, whereas ...

  11. Ship Roll Damping Control

    Perez, Tristan; Blanke, Mogens

    2012-01-01

    limitations and large variations of the spectral characteristics of wave-induced roll motion. This tutorial paper presents an account of the development of various ship roll motion control systems together with the challenges associated with their design. It discusses the assessment of performance and the...

  12. VOLATILIZED LUBRICANT EMISSIONS FROM STEEL ROLLING OPERATIONS

    The report gives results of a study of the volatilization of lubricants used in steel rolling. Data from nine steel mills were used to: define the volatilized portion of lubricants used in rolling; and prepare total oil, grease, and hydraulic material balances for actual and typi...

  13. Roll force prediction of high strength steel using foil rolling theory in cold skin pass rolling

    Skin pass rolling is a very important process for applying a certain elongation to a strip in the cold rolling and annealing processes, which play an important role in preventing the stretching of the yield point when the material is processed. The exact prediction of the rolling force is essential for obtaining a given elongation with the steel grade and strip size. Unlike hot rolling and cold rolling, skin pass rolling is used to apply an elongation of within 2% to the strip. Under a small reduction, it is difficult to predict the rolling force because the elastic deformation behavior of the rolls is complicated and a model for predicting the rolling force has not yet been established. Nevertheless, the exact prediction of the rolling force in skin pass rolling has gained increasing importance in recent times with the rapid development of high strength steels for use in automobiles. In this study, the possibility of predicting the rolling force in skin pass rolling for producing various steel grades was examined using foil rolling theory, which is known to have similar elastic deformation behavior of rolls in the roll bite. It was found that a noncircular arc model is more accurate than a circular model in predicting the roll force of high strength steel below TS 980 MPa in skin pass rolling

  14. Roll force prediction of high strength steel using foil rolling theory in cold skin pass rolling

    Song, Gil Ho; Jung, Jae Chook [Rolling and Measurement Research Group of Posco Technical Research Laboratory, Pohang (Korea, Republic of)

    2013-02-15

    Skin pass rolling is a very important process for applying a certain elongation to a strip in the cold rolling and annealing processes, which play an important role in preventing the stretching of the yield point when the material is processed. The exact prediction of the rolling force is essential for obtaining a given elongation with the steel grade and strip size. Unlike hot rolling and cold rolling, skin pass rolling is used to apply an elongation of within 2% to the strip. Under a small reduction, it is difficult to predict the rolling force because the elastic deformation behavior of the rolls is complicated and a model for predicting the rolling force has not yet been established. Nevertheless, the exact prediction of the rolling force in skin pass rolling has gained increasing importance in recent times with the rapid development of high strength steels for use in automobiles. In this study, the possibility of predicting the rolling force in skin pass rolling for producing various steel grades was examined using foil rolling theory, which is known to have similar elastic deformation behavior of rolls in the roll bite. It was found that a noncircular arc model is more accurate than a circular model in predicting the roll force of high strength steel below TS 980 MPa in skin pass rolling.

  15. CISM Course on Rolling Contact Phenomena

    Kalker, Joost

    2000-01-01

    Preface.- Rolling Contact Phenomena - Linear Elasticity.- Finite Element Methods for Rolling Contact.- Plastic Deformation in Rolling Contact.- Non-Steady State Rolling Contact and Corrugations.- Modelling of Tyre Force and Moment Generation.- Rolling Noise.- Lubrication

  16. Spray Rolling Aluminum Strip for Transportation Applications

    Kevin M. McHugh; Y. Lin; Y. Zhou; E. J. Lavernia; J.-P. Delplanque; S. B. Johnson

    2005-02-01

    Spray rolling is a novel strip casting technology in which molten aluminum alloy is atomized and deposited into the roll gap of mill rolls to produce aluminum strip. A combined experimental/modeling approach has been followed in developing this technology with active participation from industry. The feasibility of this technology has been demonstrated at the laboratory scale and it is currently being scaled-up. This paper provides an overview of the process and compares the microstructure and properties of spray-rolled 2124 aluminum alloy with commercial ingot-processed material

  17. A New Method of Manufacturing Small-Diameter Bars and Tubes from Hardly Deformable Steels in Skew Rolling

    Gałkin, A. M.

    2007-01-01

    Full Text Available The paper discusses the process of hot rolling on skew rolling mills and compares it with other methods of manufacturing rods (shape milling and tubes (pilger rolling. The method and results of calculation of the optimal price of a three-roll skew rolling mill taking into account the benefits for the purchaser and the manufacturer are given.

  18. Maintenance strategy for tilting table of rolling mill based on reliability considerations

    Reliability centred maintenance (RCM) is a new strategic framework for ensuring that any asset continues to perform, as its users want it to perform. RCM is a process used to determine the maintenance requirement of any physical asset in its operating context. RCM process entails asking seven questions about each of the selected assets. It makes use of two documents namely, RCM information worksheet and RCM decision worksheet. RCM decision diagram integrates all the decision processes into a single strategic framework. RCM concept developed by US commercial airlines industry has been successfully implemented by Military, Navy, Nuclear power plants, electric power generation and distribution undertakings and several other sectors. These projects have been carried out in the United Kingdom, The Republic of Ireland, the United States, Hong Kong, Australia, Spain and Singapore. The fact that people has enthusiastically received RCM at all levels and has enabled users to achieve some remarkable successes in all of these countries, suggests that it can be universally employed. Literature review indicates that RCM approach is not conventionally applied in process industries in India. Presently, predictive maintenance (PDM) approach along with conventional preventive maintenance is used in continuous/process industries. This approach if implemented in totality will increase the production cost to a large degree and make the production uneconomical. Similarly breakdown maintenance (BDM) approach cannot be applied in such industries as each breakdown involves huge costs. RCM approach is a compromise between PDM and BDM approach for optimising the cost and ensuring the availability of machine. The RCM approach has been applied to the tilting table system of rolling mill for the research work reported in this paper. In the present study, preventive maintenance tasks suggested for power transmission subsystem, guiding and transportation subsystem and hydraulic subsystem in

  19. Grooved roll for a high speed twin roll caster

    T. Haga

    2008-04-01

    Full Text Available Purpose: Purpose of this paper is investigation of the effect of roll-surface on the strip-surface. Improvement ofsmall cracks on the strip-surface was tried and effect of groove at the roll surface on the strip surface was shown.Design/methodology/approach: Method used in the present study was high speed twin roll caster withgrooved roll. Two kinds of grooves were used: one was parallel groove and the other was cross groove machinedby knurling and bite attached to a lathe.Findings: Findings of this research are that grooved roll was effective to eliminate the small cracks on the stripsurface. The contact condition between the roll and the melt became uniform by the small groove on the rollsurface. Contact area became small, and heat transfer between the melt and roll became small, too. As the result,chill structure did not become columnar, and crack did not occur. Groove pattern on the strip surface could beerased by the cold rolling.Research limitations/implications: Research limitation is that groove life could not be investigated.Practical implications: Practical implications are as below. The roll load was small and strip was not hot-rolledin a high speed twin roll caster. The grooved roll made strip-surface sound. Grooved 600mm width roll was tested,and usefulness of the grooved roll was shown.Originality/value: In the present study effect of the grooved roll on a high speed twin roll caster was investigated.

  20. Nanostructured MgH2 obtained by cold rolling combined with short-time high-energy ball milling

    Ricardo Floriano

    2012-01-01

    Full Text Available MgH2 was processed by short time high-energy ball milling (BM and cold rolling (CR. A new alternative processing route (CR + BM using the combination of CR followed by short time BM step was also applied. The effects on the final morphology, crystalline structure and H-sorption properties were evaluated. The CR + BM processing (compared to BM and CR process resulted in an inhomogeneous particle size distribution and the biggest crystallite size of MgH2, showing that there is a clear dependence between the size/shape of the particles which compose the starting material and the efficiency of crystallite size reduction during the BM process. On the other hand, we observed that a short BM step improved the kinetic properties of the cold rolled material. It shows that the particle size reduction of MgH2 obtained by CR combined with the increase in specific surface area attained by short BM step could be key factors to allow the use of the CR + BM route.

  1. Nanostructured MgH2 obtained by cold rolling combined with short-time high-energy ball milling

    Ricardo Floriano

    2013-02-01

    Full Text Available MgH2 was processed by short time high-energy ball milling (BM and cold rolling (CR. A new alternative processing route (CR + BM using the combination of CR followed by short time BM step was also applied. The effects on the final morphology, crystalline structure and H-sorption properties were evaluated. The CR + BM processing (compared to BM and CR process resulted in an inhomogeneous particle size distribution and the biggest crystallite size of MgH2, showing that there is a clear dependence between the size/shape of the particles which compose the starting material and the efficiency of crystallite size reduction during the BM process. On the other hand, we observed that a short BM step improved the kinetic properties of the cold rolled material. It shows that the particle size reduction of MgH2 obtained by CR combined with the increase in specific surface area attained by short BM step could be key factors to allow the use of the CR + BM route.

  2. Rolling Force and Rolling Moment in Spline Cold Rolling Using Slip-line Field Method

    ZHANG Dawei; LI Yongtang; FU Jianhua; ZHENG Quangang

    2009-01-01

    Rolling force and rolling moment are prime process parameter of external spline cold rolling. However, the precise theoretical formulae of rolling force and rolling moment are still very fewer, and the determination of them depends on experience. In the present study, the mathematical models of rolling force and rolling moment are established based on stress field theory of slip-line. And the isotropic hardening is used to improve the yield criterion. Based on MATLAB program language environment, calculation program is developed according to mathematical models established. The rolling force and rolling moment could be predicted quickly via the calculation program, and then the reliability of the models is validated by FEM. Within the range of module of spline m=0.5-1.5 mm, pressure angle of reference circle α=30.0°-45.0°, and number of spline teeth Z=19-54, the rolling force and rolling moment in rolling process (finishing rolling is excluded) are researched by means of virtualizing orthogonal experiment design. The results of the present study indicate that:the influences of module and number of spline teeth on the maximum rolling force and rolling moment in the process are remarkable;in the case of pressure angle of reference circle is little, module of spline is great, and number of spline teeth is little, the peak value of rolling force in rolling process may appear in the midst of the process;the peak value of rolling moment in rolling process appears in the midst of the process, and then oscillator weaken to a stable value. The results of the present study may provide guidelines for the determination of power of the motor and the design of hydraulic system of special machine, and provide basis for the farther researches on the precise forming process of external spline cold rolling.

  3. Spray Rolling Aluminum Strip

    Lavernia, E.J.; Delplanque, J-P; McHugh, K.M.

    2006-05-10

    Spray forming is a competitive low-cost alternative to ingot metallurgy for manufacturing ferrous and non-ferrous alloy shapes. It produces materials with a reduced number of processing steps, while maintaining materials properties, with the possibility of near-net-shape manufacturing. However, there are several hurdles to large-scale commercial adoption of spray forming: 1) ensuring strip is consistently flat, 2) eliminating porosity, particularly at the deposit/substrate interface, and 3) improving material yield. Through this program, a new strip/sheet casting process, termed spray rolling, has been developed, which is an innovative manufacturing technique to produce aluminum net-shape products. Spray rolling combines the benefits of twin-roll casting and conventional spray forming, showing a promising potential to overcome the above hurdles associated with spray forming. Spray rolling requires less energy and generates less scrap than conventional processes and, consequently, enables the development of materials with lower environmental impacts in both processing and final products. Spray Rolling was developed as a collaborative project between the University of California-Davis, the Colorado School of Mines, the Idaho National Engineering and Environmental Laboratory, and an industry team. The following objectives of this project were achieved: (1) Demonstration of the feasibility of the spray rolling process at the bench-scale level and evaluation of the materials properties of spray rolled aluminum strip alloys; and (2) Demonstration of 2X scalability of the process and documentation of technical hurdles to further scale up and initiate technology transfer to industry for eventual commercialization of the process.

  4. Using Multi-input-layer Wavelet Neural Network to Model Product Quality of Continuous Casting Furnace and Hot Rolling Mill

    HuanqinLi; JieCheng; BaiwuWan

    2004-01-01

    A new architecture of wavelet neural network with multi-input-layer is proposed and implemented for modeling a class of large-scale industrial processes. Because the processes are very complicated and the number of technological parameters, which determine the final product quality, is quite large, and these parameters do not make actions at the same time but work in different procedures, the conventional feed-forward neural networks cannot model this set of problems efficiently. The network presented in this paper has several input-layers according to the sequence of work procedure in large-scale industrial production processes. The performance of such networks is analyzed and the network is applied to model the steel plate quality of continuous casting furnace and hot rolling mill. Simulation results indicate that the developed methodology is competent and has well prospects to this set of problems.

  5. MENDED GENETIC BP NETWORK AND APPLICATION TO ROLLING FORCE PREDICTION OF 4-STAND TANDEM COLD STRIP MILL

    Zhang Dazhi; Sun Yikang; Wang Yanping; Cai Hengjun

    2004-01-01

    In order to make good use of the ability to approach any function of BP (back propagation) network and overcome its local astringency,and also make good use of the overall search ability of GA (genetic algorithms),a proposal to regulate the network's weights using both GA and BP algorithms is suggested.An integrated network system of MGA (mended genetic algorithms) and BP algorithms has been established.The MGA-BP network's functions consist of optimizing GA performance parameters,the network's structural parameters,performance parameters,and regulating the network's weights using both GA and BP algorithms.Rolling forces of 4-stand tandem cold strip mill are predicted by the MGA-BP network,and good results are obtained.

  6. Oil Film Compensation Control of Hydraulic AGC System in Tandem Cold Rolling Mill%冷连轧机液压AGC系统油膜补偿控制

    孙孟辉; 王益群

    2011-01-01

    Since the request to the quality of cold rolling sheet strips is higher, the hydraulic AGC ( Automatic Gauge Control) has become the indispensable means which improves the product precision of cold rolling strips. However, to the tandem cold rolling mill which backup roll adopts the oil film bearing, the thickness of oil film changes with different rolling force and rolling velocity, which influences the exit thickness of strips and brings the thickness deviation. Especially for the tandem cold rolling mill, the accumulative deviation of every stand enlarges more the deviation of steel product. The oil film compensation model, which adapted to the practical control, was regressed from the data measured from production locale, aiming at one 5-stand tandem cold rolling mill as object. The control strategy was brought forward, which adapted to the distributed computer control. All of them were applied in the practical rolling process for compensation of changes in thickness of oil film. The experimental result indicates that length of out-toler-ance and value of out-tolerance between head and tail of steel product are reduced notably.%由于对冷轧薄板质量要求的提高,液压AGC已经成为提高冷轧带钢成品精度必不可少的手段.然而对于支撑辊采用油膜轴承的冷连轧机来说,其轴承油膜厚度随着轧制力和轧制速度的变化而变化,这将影响轧件的轧出厚度,造成厚差.尤其对冷连轧机,各机架的累积误差会使成品带的超差更加严重.以某五机架冷连轧机为研究对象,由生产现场实测数据回归出适合于实际控制的油膜补偿模型,提出适合于分布式计算机控制的控制策略,并将其应用于实际轧制过程中对油膜厚度变化进行补偿.实验结果表明:加入油膜补偿控制后,成品带钢厚差带头带尾超差段有较为显著的减少,且超差值也有所降低.

  7. Comparison between a high chromium steel and a semi HSS grades used as work rolls in the roughing stands of a hot strip mill

    Tchuindjang, Jérôme Tchoufack; Lecomte-Beckers, Jacqueline

    2010-01-01

    Two alloys grades for work rolls used in the roughing stand of Hot Strip Mill (HSM) were compared. The first grade known as High Chromium Steel (HCS) is actually the alloy widely used for such an application, while the second one known as semi-High Speed Steel (semi-HSS) is the new grade developed to improve overall properties of the work roll in the roughing stands of the HSM. In the present work, the new semi-HSS grade is studied starting from 3 chemical compositions closed one to anoth...

  8. Sliding and Rolling: The Physics of a Rolling Ball.

    Hierrezuelo, J.; Carnero, C.

    1995-01-01

    Presents an approach that provides a simple and adequate procedure for introducing the concept of rolling friction. Discusses some aspects related to rolling motion that are the source of students' misconceptions. Presents several didactic suggestions. (JRH)

  9. Rolling at small scales

    Nielsen, Kim L.; Niordson, Christian F.; Hutchinson, John W.

    2016-01-01

    The rolling process is widely used in the metal forming industry and has been so for many years. However, the process has attracted renewed interest as it recently has been adapted to very small scales where conventional plasticity theory cannot accurately predict the material response. It is well...... plasticity. Metals are known to be stronger when large strain gradients appear over a few microns; hence, the forces involved in the rolling process are expected to increase relatively at these smaller scales. In the present numerical analysis, a steady-state modeling technique that enables convergence...

  10. Thermal Behaviors of Work Roll in Finishing Trains of Hot Rolling

    2001-01-01

    In order to analyze the thermal field and thermal contour of work roll in finishing trains of hot rolling in rolling process, a quasi two-dimension implicit finite difference model is developed. To improve the calculating speed and precision, some special solutions are introduced, including the development of this model, the simplification of boundary conditions and the computation of heat transfer coefficients. The results show that these solutions of thermal behaviors of work roll are very much efficient and the model can be used as an on-line profile and flatness control model of large industrial mills.

  11. Strip Crown Prediction: Developing a Refined Dynamic Roll-Stack Model for the Hot Rolling Process

    Slaughter, Derek Emerson

    2009-01-01

    The steel industry has been producing flat plates through the process of hot rolling since the late 1600s. Hot rolling uses a series of rolls to progressively thin a strip of steel to a desired thickness. In deforming the strip, the rolling process causes variations in thickness across the width of the strip. These variations are commonly referred to as crown, which is specifically the difference in thickness between the center and edge of a strip. For most applications steel mill clients req...

  12. A new transducer for local load measurements of friction and roll pressure in cold flat rolling

    Lagergren, J.; Wanheim, Tarras; Precz, W.; Henningsen, Poul; Arentoft, Mogens; Jonsson, N.G.

    2006-01-01

    The only way to establish the true rolling pressure and the true friction condition in cold rolling is to conduct measurements in the roll bite. A new transducer design is therefore proposed, in order to overcome problems in previous measurements in the past 70 years. The new idea is to increase...... the contact surface of the transducer, to be larger than the arc of contact. This is in contrast to the smaller and smaller contact pin design that has been prevailing. The measurements were conducted during cold dry rolling of both copper strips and stainless steel strips in a pilot mill. The...

  13. Slitting criterion for various rolling speeds in MSR rolling process

    A. Stefanik

    2008-03-01

    Full Text Available Purpose: The main idea of MSR technology is the capability of producing two, three, four and even five rods simultaneously from a single strip in a hot rolling process. Correctly separation of the joined strips is the one of the mainly problem in MSR process. Changing the rolling speed may causes easier of the strand division. In this paper results of the computer simulation of the double slitting rolling process were presented.Design/methodology/approach: For numerical modelling of the multi rolling process a computer program Forge 2005, based by the finished element method was used. As a slitting criterion normalised Cockroft – Latham criterion was used.Findings: For the analysis performed in this study, it was found that increasing of the rolling speed causes of increasing the normalized Cockroft – Latham criterion. For the small values of rolling velocity the strip separation was easier.Research limitations/implications: Multi Slit Rolling process is applied in ribbed rods rolling. Adjusting of the rolling speed in multi slit rolling process could improve of the slitting band to the separated strips.Originality/value: Incorrect construction or bad gap matching could cause lack of separation propelled slitting rolls. The separation of the band is effected by means of separating rollers, which shape must be properly designed to suit to the slitting pass. Changing of the rolling speed could improve of the separation to the single strips.

  14. Effects of finishing rolling temperatures and reduction on the mechanical properties of hot rolled multiphase steel

    LI Zhuang; WU Di

    2007-01-01

    Effects of finishing rolling temperatures and reduction on the mechanical properties of hot rolled multiphase steel were investigated. Thermo-mechanical control processing (TMCP) was conducted by using a laboratory hot rolling mill, in which three different kinds of finishing rolling temperatures and reduction and various austempering times were applied. The results showed that polygonal ferrite, granular bainite and larger amount of stabilized retained austenite can be obtained by controlled rolling processes, and that the strain-induced transformation to martensite from the retained austenite can occur gradually when the steel is deformed during tensile test. Mechanical properties increase with decreasing finishing rolling temperature and increasing amount of deformation. The most TRIP (transformation induced plasticity) effect, and ultimate tensile strength (UTS), total elongation (TEL) and the product of ultimate tensile strength and total elongation (UTS× TEL) are obtained at 20 min.

  15. Effect of plate asymmetric rolling parameters on the change of the total unit pressure of roll

    A. Kawalek

    2011-07-01

    Full Text Available This work shows the results of theoretical analysis of asymmetric rolling process of plates in the finishing mill of plate rolling. Its aim was to determine the influence of asymmetry velocity of working rolls on decrease of unit pressure of metal on the rolls. The lower value of the unit pressure will reduce the elastic deflection of the finishing stand and improve the cross-section shape of plate. Three-dimensional simulation of asymmetric hot rolling of S355J2G3 steel plates was done with the aid of FORGE 2008® software. The tensor polynomial interpolation was used for comparing the values of the unit pressure obtaining from symmetric and asymmetric rolling.

  16. Ship Roll Motion Control

    Perez, Tristan; Blanke, Mogens

    2010-01-01

    . This tutorial paper presents an account of the development of various ship roll motion control systems and the challenges associated with their design. The paper discusses how to assess performance, the applicability of dierent models, and control methods that have been applied in the past....

  17. Person og Rolle

    Szatkowski, Janek

    2011-01-01

    Distinktionen mellem person og rolle forslås som grundlag for et præcist og anlytisk anvendeligt begreb om performativitet. Begrebet tager sigte på at beskrive enkeltindividers og gruppers kommunikation med henblik på hvordan kommunikation etableres. Performativitet gør det muligt at iagttage den...

  18. Rolling Cylinder Phase 1

    Margheritini, Lucia; Taraborrelli, Valeria Taraborrelli

    Margheritini and Valeria Taraborrelli(valeria.taraborrelli@hotmail.it) with a total of 3 day visit from the developers. Laboratory tests in irregular waves will be performed by Lucia Margheritini. The report is aimed at the first stage testing of the Rolling Cylinder wave energy device. This phase includes...

  19. 冷连轧机辊型配置对高强钢板形控制的影响%Effect of Roll Shape Configuration of Cold Continuous Mill on High-strength Strip Profile

    吴彬; 张清东; 张晓峰

    2012-01-01

    针对薄规格高强钢板形控制困难问题,通过建立有限元模型分析了常规支撑辊+ CVC中间辊、CVC补偿支撑辊+ CVC中间辊及VCL+支撑辊+HVC中间辊3种代表性辊型配置对高强度冷轧板的板形控制能力的影响.与其他2种辊型配置方案相比,VCL+支撑辊+HVC中间辊辊型配置的承载辊缝的凸度调节域较大、横向刚度较高,辊间接触压力较小.实际生产表明,在该辊型配置方案下,高强度带钢的板形控制精度较高,支撑辊磨损得到有效改善.%To the problem of the shape of high-strength sheet difficult to control, the influences of three representative forms of roll profile configuration on high-strength strip shape control in CVC cold continuous rolling mill are compared by FEM model, which are conventional back-up roll + CVC intermediate roll, back-up roll with CVC compensation + CVC intermediate roll, VCL+ back-up roll + HVC intermediate roll. Compared with the other two roll profile configuration, the configuration of VCL+ back-up roll + HVC intermediate roll increases crown adjustment room and lateral stiffness of loaded roll gap, decreases contact pressure between rolls. The production practice shows that the control accuracy of high-strength strip shape and wear of back-up roll are improved by it.

  20. ANALYTICAL INVESTIGATIONS OF WORKLOADS OF THE RUP «BMZ» MILL 320 WORKING STANDS AT ROLLING OF FITTINGS OF SLUGS WITH INCREASED SECTION USING THE SYSTEM OF MINIMUM TENSION

    V. N. Kuvaev

    2010-01-01

    Full Text Available Analytical investigations of workloads of the RUP «BMZ» mill 320 working stands at rolling of fittings of slugs with section 140´140 mm using the system of minimum tension are carried out. 

  1. GRCop-84 Rolling Parameter Study

    Loewenthal, William S.; Ellis, David L.

    2008-01-01

    This report is a section of the final report on the GRCop-84 task of the Constellation Program and incorporates the results obtained between October 2000 and September 2005, when the program ended. NASA Glenn Research Center (GRC) has developed a new copper alloy, GRCop-84 (Cu-8 at.% Cr-4 at.% Nb), for rocket engine main combustion chamber components that will improve rocket engine life and performance. This work examines the sensitivity of GRCop-84 mechanical properties to rolling parameters as a means to better define rolling parameters for commercial warm rolling. Experiment variables studied were total reduction, rolling temperature, rolling speed, and post rolling annealing heat treatment. The responses were tensile properties measured at 23 and 500 C, hardness, and creep at three stress-temperature combinations. Understanding these relationships will better define boundaries for a robust commercial warm rolling process. The four processing parameters were varied within limits consistent with typical commercial production processes. Testing revealed that the rolling-related variables selected have a minimal influence on tensile, hardness, and creep properties over the range of values tested. Annealing had the expected result of lowering room temperature hardness and strength while increasing room temperature elongations with 600 C (1112 F) having the most effect. These results indicate that the process conditions to warm roll plate and sheet for these variables can range over wide levels without negatively impacting mechanical properties. Incorporating broader process ranges in future rolling campaigns should lower commercial rolling costs through increased productivity.

  2. Walk and roll robot

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2011-01-01

    A mobile robotic unit features a main body, a plurality of legs for supporting the main body on and moving the main body in forward and reverse directions about a base surface, and a drive assembly. According to an exemplary embodiment each leg includes a respective pivotal hip joint, a pivotal knee joint, and a wheeled foot adapted to roll along the base surface. Also according to an exemplary embodiments the drive assembly includes a motor operatively associated with the hip and knee joints and the wheeled foot for independently driving pivotal movement of the hip joint and the knee joint and rolling motion of the wheeled foot. The hip joint may include a ball-and-socket-type joint interconnecting top portion of the leg to the main body, such that the hip joint is adapted to pivot said leg in a direction transverse to a forward-and-reverse direction.

  3. Roll waves in mud

    Balmforth, N. J.; Liu, J J

    2004-01-01

    The stability of a viscoplastic fluid film falling down an inclined plane is explored, with the aim of determining the critical Reynolds number for the onset of roll waves. The Herschel–Bulkley constitutive law is adopted and the fluid is assumed two-dimensional and incompressible. The linear stability problem is described for an equilibrium in the form of a uniform sheet flow, when perturbed by introducing an infinitesimal stress perturbation. This flow is stable for very high Reynolds numbe...

  4. Rolling bearing analysis

    Harris, Tedric A

    2001-01-01

    One of the most well-known experts in the field brings cutting-edge research to practitioners in the new edition of this important reference. Covers the improved mathematical calculations for rolling bearing endurance developed by the American Society of Mechanical Engineers and the Society of Lubrication and Tribology Engineers. Updated with new material on Condition-Based Maintenance, new testing methods, and new bearing materials.

  5. Assessment of Air Pollution and its Effects on Health of Workers of Steel Re-Rolling Mills in Hyderabad

    Altaf Alam Noonari

    2016-04-01

    Full Text Available The SRRMs (Steel Re-Rolling Mills are being releasing air pollutants in the environment. In order to evaluate their effect on the health of the workers, health and safety issues were analyzed by first measuring the concentrations of SO x (OIxides of Sulphur, NO x (Oxides of Nitrogen, CO (Carbon Monoxide and O2 (Oxygen produced in the three SRRMs located in SITE area Hyderabad. The mean concentration of SO x , NO x and CO were in the order of 0.35, 0.280, 6.333 ppm, respectively, whereas the mean concentration of O 2 was 203.53 thousand ppm. As per results, the concentration ofair pollutants, including SOx and NO x were significantly higher than to the NEQS (National Environmental Quality Standards and NAAQS (National Ambient Air Quality Standards. The concentration ofCO was lower than to the NAAQS, but higher than to the NEQs, while the concentration of O2 was slightly lower than to the standard value. The workers who were exposed to these air pollutants are being suffering from chronic diseases related to breathing and allergies. Moreover, labour staff was lifting heavy loads manually, which causes them to muscular and joint problems. In all the SRRMs under study, the electrical and mechanical equipments were used without any safety. The MSDS were not displayed on the workstations, the housekeeping was inadequate and most of the workers were performing their jobs without personal protective equipment. In addition to these, the other serious issues related to the occupational health and safety were an unhygienic supply of water, higher noise level, placement of explosive cylinders in the open atmosphere and unavailability of the first aid facilities in the Mill premises.

  6. Hot rolling joining process

    In the case of incorporating nonferrous metal equipment in fuel reprocessing processes, from the viewpoint of reducing maintenance works for the piping connection to peripheral equipments, it is desirable to adopt the pipe joints of joining the materials of different kinds, which have the high reliability against leakage. In order to meet this demand, the development of the manufacturing technology of the pipe joints by hot rolling process has been carried out. As for the structure of this pipe joint, a small diameter nonferrous metal pipe and a large diameter stainless steel pipe are joined by hot rolling by using an inserted material. The materials are Ti-5% Ta, Ti and Zr for the nonferrous metals, SUS 304L for the stainless steel, and Ta foil for the inserted material. The merits and demerits of this pipe joints are shown. The control of the interface structure in the joining of different materials was carried out by using the inserted material. The method of manufacturing the pipe joints and the proper conditions of the rolling joining are explained. As for the performance of the pipe joints, the evaluations of the defects in the joining interface, the strength of the joining, the corrosion resistance and the susceptibility to stress corrosion cracking are reported. (K.I.)

  7. A study on centrifugal casting of high speed steel roll

    2004-01-01

    High speed steel (HSS) rolls can replace traditional rolls such as alloyed cast iron rolls and powder metallurgical (PM) hard alloy rolls. The main reasons for the replacement are that the wear resistance of low-cost alloyed cast iron rolls is poor and the cost of high-quality PM hard alloy rolls is very high. By means of centrifugal casting, HSS rolls having excellent wear resistance have been manufactured. The hardness of the HSS roll is 65~ 67 HRC, the range of variation is smaller than 2 HRC and its impact toughness is 15 J/cm2. The wear rate of HSS rolls used in the pre-finishing stands of high-speed hot wire-rod rolling mill reaches 2.5 × 10-4 mm per ton steel. Furthermore, the manufacturing cost of HSS rolls is significantly lower than that of PM hard alloy rolls; it is only 30 percent of that of PM hard alloy rolls.

  8. A Web-based Condition Monitoring and Diagnostic System of Rolling Mill

    2002-01-01

    A web-based condition monitoring and fault diagnosis system (CMAFDS) for the F2 finishing mill of the 2050 Hot Strip Mill was developed at a steel works. The features of the condition monitoring and fault diagnosis system based on the Web are analyzed in this paper. This paper also describes the main frame of the hardware and the software in the system and emphatically points out the function of the database management system(DBMS) based on the Web. It is proved that the web-based CMAFDS is practical in technology and much superior to the CMAFDS based on other network technology in functions.

  9. Simulation of accelerated strip cooling on the hot rolling mill run-out roller table

    E.Makarov

    2016-07-01

    Full Text Available A mathematical model of the thermal state of the metal in the run-out roller table continuous wide hot strip mill. The mathematical model takes into account heat generation due to the polymorphic γ → α transformation of supercooled austenite phase state and the influence of the chemical composition of the steel on the physical properties of the metal. The model allows calculation of modes of accelerated cooling strips on run-out roller table continuous wide hot strip mill. Winding temperature calculation error does not exceed 20°C for 98.5 % of strips of low-carbon and low-alloy steels

  10. Rolling motion in moving droplets

    Sumesh P Thampi; Rama Govindarajan

    2015-03-01

    Drops moving on a substrate under the action of gravity display both rolling and sliding motions. The two limits of a thin sheet-like drop in sliding motion on a surface, and a spherical drop in roll, have been extensively studied. We are interested in intermediate shapes. We quantify the contribution of rolling motion for any intermediate shape, and recently obtained a universal curve for the amount of roll as a function of a shape parameter using hybrid lattice Boltzmann simulations. In this paper, we discuss the linear relationship which is expected between the Capillary and Bond numbers, and provide detailed confirmation by simulations. We also show that the viscosity of the surrounding medium can qualitatively affect dynamics. Our results provide an answer to a natural question of whether drops roll or slide on a surface and carry implications for various applications where rolling motion may or may not be preferred.

  11. Lipoid pneumonia caused by oil mist exposure from a steel rolling tandem mill

    Cullen, M.R.; Balmes, J.R.; Robins, J.M.; Smith, G.J.

    1981-01-01

    Five of nine active tandem mill operators exposed at work to aerosolized hydrocarbon mist were referred for evaluation of respiratory complaints. The worker with the longest exposure had reduced lung volumes; he was admitted to the hospital for detailed study. Exercise studies revealed work load limited by ventilation and arterial oxygen desaturation. Flexible fiberoptic bronchoscopy with bronchoalveolar lavage and transbronchial biopsy revealed evidence of lipoid pneumonia. Assessment of the mill revealed levels of respirable oil mist by personal samplers throughout the area far below the currently accepted standard of 5 mg/M3. These findings confirm a 20-year-old hypothesis of J.G. Jones regarding the hazard of oil mist in this industrial setting.

  12. DEFECTS SIMULATION OF ROLLING STRIP

    Rudolf Mišičko; Tibor Kvačkaj; Martin Vlado; Lucia Gulová; Miloslav Lupták; Jana Bidulská

    2009-01-01

    The defects in the continuous casting slabs can be developed or kept down in principle by rolling technology, especially depend to sort, size and distribution of primary defects, as well as used of rolling parameters. Scope of the article is on observation behavior artificial surface and undersurface defects (scores) without filler (surface defects) and filling by oxides and casting powder (subsurface defects). First phase of hot rolling process have been done by software simulation DEFORM 3D...

  13. Development of centrifugal casting high speed steel rolls

    Hanguang Fu; Aimin Zhao; Jiandong Xing

    2003-01-01

    The present study aims at developing the high speed steel (HSS) as roll materials to replace the traditional roll materials such as the alloy cast iron and powder metallurgical (PM) hard alloy. The HSS roll billet was formed by centrifugal casting, and the billet was rough machined after soften annealing heat treatment, then it was quenched and tempered to get suitable hardness and toughness. After that the HSS roll was finish machined to the final dimension of φ285 mm in the outer diameter, φ160 mm in the inner diameter and 120 mm in width and its surface hardness was tested. Finally the HSS roll was used in high speed wire rod mill. The test results show that a high and homogeneous hardness can obtain on the work surface of HSS rolls, the surface hardness is 63-65HRC and its variation is smaller than 2HRC. The impact toughness of this kind of HSS is about 16 J/cra2. The results of on-line service investigation in high speed wire rod mill indicate that the HSS rolls have excellent wear resistance, the steel rolling quantity per mm of HSS rolls is 3120 t, the service life-span of HSS rolls is 4 times longer than that of high chromium cast iron rolls and it is close to that of the PM hard alloy rolls. The manufacturing burden of HSS rolls is obviously lower than that of the PM hard alloy rolls, it is only 25% of that of the PM hard alloy rolls.

  14. 1150mm可逆冷轧机液压自动控制系统%Automatic Control System of 1 150 mm Reversible Cold Rolling Mill

    王孝科; 张海军; 薛风春

    2011-01-01

    介绍1 150mm单机架冷轧机自动控制系统的硬件配置、软件配置和传感器配置,说明液压自动控制系统的位置闭环控制原理和压力闭环控制原理,重点阐述厚度控制系统中的前馈AGC、监控AGC、流量AGC和加减速厚度补偿.现场实际应用表明:成品相对厚度精度优于±1%,超差长度大大缩短,满足了实际生产的要求.%Hardware, software and sensor configuration of automatic control system for 1150 nun single stand cold rolling mill were introduced. Principles of position close loop control and rolling force close loop control in automation control system of rolling mill were explained. Feed forward AGC, monitoring AGC, mass flow AGC and gauge compensation during acceleration and deceleration in gauge control system were described in detail. Practical application shows that relative thickness accuracy of products is within ± 1% , the ultra-poor length is shortened greatly and it meets the need of practical production.

  15. Rolling cuff flexible bellows

    Lambert, Donald R.

    1985-01-01

    A flexible connector apparatus used to join two stiff non-deformable members, such as piping. The apparatus is provided with one or more flexible sections or assemblies each utilizing a bellows of a rolling cuff type connected between two ridge members, with the bellows being supported by a back-up ring, such that only the curved end sections of the bellows are unsupported. Thus, the bellows can be considered as being of a tube-shaped configuration and thus have high pressure resistance. The components of the flexible apparatus are sealed or welded one to another such that it is fluid tight.

  16. Using Variable Perturbation Method to Study the Stability of Torsional Self-Excited Vibration in Main Drive System of Rolling Mill

    Fenglan Wang

    2013-06-01

    Full Text Available The self-excited vibration of blooming mill is a kind of torsional vibration, which occurs only when the rolling machine slips under appropriate conditions. Once in place, this may cause the larger peak pressure of each component in the main drive system; reduce the service life of the components, cause components′ damage directly. A large number of studies have shown that, at present there are not effective methods for diagnosis, monitoring of slipping and take proper measures in time to stop slipping so as to avoid the occurrence of malignant accidents. In this paper, author set out from another angle, take the main drive system of rolling mill as an example, to study stability of self-excited vibration. The conditions of the stable vibration are gained. By combining with the actual working conditions of blooming mill, author has put forward some effective measures to meet the stable conditions in order to make the blooming mill work in the stable state. Practice research has proved that the effective measures can contribute to reduce structural damage directly caused by the torsional vibration when “slipping” phenomenon occurred and to extend the service life of the components.

  17. Analysis of roll gap heat transfers in hot steel strip rolling through roll temperature sensors and heat transfer models

    WEISZ-PATRAULT, Daniel; Ehrlacher, Alain; Legrand, Nicolas; LABBE, Nathalie; Horsky, Jaroslav; Luks, Tomas

    2012-01-01

    This paper presents an analysis of roll bite heat transfers during pilot hot steel strip rolling. Two types of temperature sensors (drilled and slot sensors) implemented near roll surface are used with heat transfer models to identify interfacial heat flux, roll surface temperature and Heat Transfer Coefficient HTCroll-bite in the roll bite. It is shown that: - the slot type sensor is more efficient than the drilled type sensor to capture correctly fast roll temperature changes and heat fluxe...

  18. Planejamento e controle da produção de cilindros para laminação: um estudo de caso quantitativo Production management of rolling mill rolls: a quantitative study case

    Laerte José Fernandes

    2013-03-01

    Full Text Available Este trabalho apresenta um modelo de otimização-simulação aplicado em um estudo de caso real no setor de cilindros para laminação de uma siderúrgica, buscando melhorar o gerenciamento da área/equipamento gargalo da linha de produção. A simulação atuou em conjunto com um modelo de otimização da programação linear inteira (PLI para melhorar o atendimento de prazo junto aos clientes em uma produção não seriada. Como resultado deste procedimento combinado da PLI e simulação, o processo produtivo foi otimizado e as filas de espera e o lead-time foram reduzidos, melhorando o atendimento aos clientes.This article presents a simulation-optimization model application for a real case study in the rolling mill roll sector of a steel plant. The purpose of this study was to get a better area/equipment bottleneck management in the production line. The simulation was used together with an ILP (Integer Linear Programming optimization model, in order to improve customer service in a made-to-order production. As a result of this ILP and Simulation combined approach, the productive process was optimized and both queues and lead-time were reduced, improving customer service.

  19. Video Analysis of Rolling Cylinders

    Phommarach, S.; Wattanakasiwich, P.; Johnston, I.

    2012-01-01

    In this work, we studied the rolling motion of solid and hollow cylinders down an inclined plane at different angles. The motions were captured on video at 300 frames s[superscript -1], and the videos were analyzed frame by frame using video analysis software. Data from the real motion were compared with the theory of rolling down an inclined…

  20. Phase dynamics of convective rolls

    Cross, M. C.

    1983-01-01

    The equation of motion for the slow time dependence of convective rolls due to long-wavelength inhomogeneities is shown to have a singular dependence on the wave vector of the disturbance. Consequences for the skew varicose instability and the wave-number selection principle in textures of curved rolls suggested by Pomeau and Manneville are discussed.

  1. Computational design of rolling bearings

    Nguyen-Schäfer, Hung

    2016-01-01

    This book comprehensively presents the computational design of rolling bearings dealing with many interdisciplinary difficult working fields. They encompass elastohydrodynamics (EHD), Hertzian contact theory, oil-film thickness in elastohydrodynamic lubrication (EHL), bearing dynamics, tribology of surface textures, fatigue failure mechanisms, fatigue lifetimes of rolling bearings and lubricating greases, Weibull distribution, rotor balancing, and airborne noises (NVH) in the rolling bearings. Furthermore, the readers are provided with hands-on essential formulas based on the up-to-date DIN ISO norms and helpful examples for computational design of rolling bearings. The topics are intended for undergraduate and graduate students in mechanical and material engineering, research scientists, and practicing engineers who want to understand the interactions between these working fields and to know how to design the rolling bearings for automotive industry and many other industries.

  2. The rotary unit of mandrel on vertical ring rolling mill%立式辗环机的芯辊转动装置

    江绍成; 袁汉江

    2011-01-01

    目前,国内外各种辗环机的芯辊都是由主辗压轮通过被辗的环件而带动旋转的.对普通立式辗环机而言,环坯是立套在芯辊上,主辗压轮的切向摩擦力就必须大于环坯和芯辊及下支承的转动惯量及其他转动阻力,否则主辗压轮不仅不能带转环坯,反而压入环坯外表面形成凹坑,从而使辗环过程无法进行.尤其对内外圆偏心较大的大型环坯,带转更加费力,这也是限制立式辗环机的大型化和环坯重量的重要原因之一.为解决这个问题,设计了结构简单的芯辊转动装置,使芯辊由被动带转变成主动旋转,不仅方便了操作,且为立式辗环机的大型化创造了条件.%Up to now, the mandrels of the ring rolling mill all over the world are rotated passively by the workpiece through the main rolling wheel. For the ordinary vertical mill, the ring blank is sleeved on the mandrel. The friction of the main rolling wheel has to above the rotary inertia and other resistance of ring blank and lower support. Otherwise, the main rolling wheel can't rotate the blank and would damage the surface of the blank, especially for large blank with big inner and outer eccentricity, which is the main reason of restricting the large weight and size of vertical mill. In order to solve the above problem, the mandrel rotary unit with simple structure has been designed, which turns passive rotary into active rotary and creates possibility for the large weight and size of the vertical mill.

  3. Development of a rolling technology for twin-roll cast magnesium strips

    M. Ullmann

    2015-10-01

    Full Text Available With the best lightweight potential of all metallic construction materials, magnesium primarily helps to increase energy efficiency over the lifecycle of automotive and non-automotive industrial products. Yet to assess overall energy efficiency, the production process must also be taken into account. This paper provides an insight into the energy-efficient production of magnesium strips up to 0,8 mm in thickness based on twin-roll casting and strip rolling on an industrial scale, as developed at the Institute of Metal Forming at the Technical University Bergakademie Freiberg (Germany in cooperation with MgF Magnesium Flachprodukte GmbH (Germ any. The technology of twin-roll casting and strip rolling on a four-high reversing mill is described.

  4. Steel balls forming by cross rolling with upsetting

    Z. Pater

    2013-01-01

    Full Text Available The paper describes a process of forming four balls with a diameter of 22 mm by means of cross rolling with upsetting. The paper also presents the tool used to form semi-finished balls. Owing to the application of the finite element method (FEM, the course of the rolling process as well as temperature and strain distributions in the obtained balls could be presented. The rolling tests conducted in laboratory conditions at the Lublin University of Technology have proved that the balls produced with the developed rolling method meet the demands for grinding media used in ball mills.

  5. Roll Control in Fruit Flies

    Beatus, Tsevi; Cohen, Itai

    2014-01-01

    Due to aerodynamic instabilities, stabilizing flapping flight requires ever-present fast corrective actions. Here we investigate how flies control body roll angle, their most susceptible degree of freedom. We glue a magnet to each fly, apply a short magnetic pulse that rolls it in mid-air, and film the corrective maneuver. Flies correct perturbations of up to $100^{\\circ}$ within $30\\pm7\\mathrm{ms}$ by applying a stroke-amplitude asymmetry that is well described by a linear PI controller. The response latency is $\\sim5\\mathrm{ms}$, making the roll correction reflex one of the fastest in the animal kingdom.

  6. Kinetic Modeling of Roll to Roll RFCVD Plasma

    Ahegbebu, Kudzo S; Tholeti, Siva Sashank; Alexeenko, Alina A

    2015-01-01

    Roll-to-roll radio frequency plasma enhanced chemical vapor deposition (R2R RFCVD) is a technique for large-scale synthesis of high quality graphitic nanopetals. Graphitic nanopetals are petal-like graphene structures with remarkable electrical and mechanical properties with major industrial applications such as microsupercapacitors. RFCVD uses a non-equilibrium plasma with high energy electrons to catalyze chemical reactions, induce the creation of free radicals, and promote otherwise high t...

  7. AISI/DOE Advanced Process Control Program Vol. 3 of 6: MICROSTRUCTURAL ENGINEERING IN HOT-STRIP MILLS Part 2 of 2: Constitutive Behavior Modeling of Steels Under Hot-Rolling Conditions

    Yi-Wen Cheng; Patrick Purtscher

    1999-07-30

    This report describes the development of models for predicting (1) constitutive behaviors and (2) mechanical properties of hot-rolled steels as functions of chemical composition, microstructural features, and processing variables. The study includes the following eight steels: A36, DQSK, HSLA-V, HSLA-Nb, HSLA-50/Ti-Nb, and two interstitial-free (IF) grades. These developed models have been integrated into the Hot-Strip Mill Model (HSMM), which simulates the hot strip rolling mills and predicts the mechanical properties of hot-rolled products. The HSMM model has been developed by the University of British Columbia-Canada as a part of project on the microstructural engineering in hot-strip mills.

  8. AISI/DOE Advanced Process Control Program Vol. 3 of 6: MICROSTRUCTURAL ENGINEERING IN HOT-STRIP MILLS Part 2 of 2: Constitutive Behavior Modeling of Steels Under Hot-Rolling Conditions; FINAL

    This report describes the development of models for predicting (1) constitutive behaviors and (2) mechanical properties of hot-rolled steels as functions of chemical composition, microstructural features, and processing variables. The study includes the following eight steels: A36, DQSK, HSLA-V, HSLA-Nb, HSLA-50/Ti-Nb, and two interstitial-free (IF) grades. These developed models have been integrated into the Hot-Strip Mill Model (HSMM), which simulates the hot strip rolling mills and predicts the mechanical properties of hot-rolled products. The HSMM model has been developed by the University of British Columbia-Canada as a part of project on the microstructural engineering in hot-strip mills

  9. Manufacturing Demonstration Facility: Roll-to-Roll Processing

    Datskos, Panos G [ORNL; Joshi, Pooran C [ORNL; List III, Frederick Alyious [ORNL; Duty, Chad E [ORNL; Armstrong, Beth L [ORNL; Ivanov, Ilia N [ORNL; Jacobs, Christopher B [ORNL; Graham, David E [ORNL; Moon, Ji Won [ORNL

    2015-08-01

    This Manufacturing Demonstration Facility (MDF)e roll-to-roll processing effort described in this report provided an excellent opportunity to investigate a number of advanced manufacturing approaches to achieve a path for low cost devices and sensors. Critical to this effort is the ability to deposit thin films at low temperatures using nanomaterials derived from nanofermentation. The overarching goal of this project was to develop roll-to-roll manufacturing processes of thin film deposition on low-cost flexible substrates for electronics and sensor applications. This project utilized ORNL s unique Pulse Thermal Processing (PTP) technologies coupled with non-vacuum low temperature deposition techniques, ORNL s clean room facility, slot dye coating, drop casting, spin coating, screen printing and several other equipment including a Dimatix ink jet printer and a large-scale Kyocera ink jet printer. The roll-to-roll processing project had three main tasks: 1) develop and demonstrate zinc-Zn based opto-electronic sensors using low cost nanoparticulate structures manufactured in a related MDF Project using nanofermentation techniques, 2) evaluate the use of silver based conductive inks developed by project partner NovaCentrix for electronic device fabrication, and 3) demonstrate a suite of low cost printed sensors developed using non-vacuum deposition techniques which involved the integration of metal and semiconductor layers to establish a diverse sensor platform technology.

  10. SENSITIVITY ANALYSIS FOR ROLLING PROCESS BASED ON SUPPORT VECTOR MACHINE

    Huang Yanwei; Wu Tihua; Zhao Jingyi; Wang Yiqun

    2005-01-01

    A method for the calculation of the sensitivity factors of the rolling process has been obtained by differentiating the roll force model based on support vector machine. It can eliminate the algebraic loop of the analytical model of the rolling process. The simulations in the first stand of five stand cold tandem rolling mill indicate that the calculation for sensitivities by this proposed method can obtain a good accuracy, and an appropriate adjustment on the control variables determined directly by the sensitivity has an excellent compensation accuracy. Moreover, the roll gap has larger effect on the exit thickness than both front tension and back tension, and it is more efficient to select the roll gap as the controlvariable of the thickness control system in the first stand.

  11. Rolling Process Modeling Report: Finite-Element Prediction of Roll Separating Force and Rolling Defects

    Soulami, Ayoub [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paxton, Dean M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-04-23

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum (U-10Mo) alloy plate-type fuel for the U.S. high-performance research reactors. This work supports the Convert Program of the U.S. Department of Energy’s National Nuclear Security Administration (DOE/NNSA) Global Threat Reduction Initiative. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll separating forces and rolling defects. Simulations were performed using a finite-element model developed using the commercial code LS-Dyna. Simulations of the hot rolling of U-10Mo coupons encapsulated in low-carbon steel have been conducted following two different schedules. Model predictions of the roll-separation force and roll-pack thicknesses at different stages of the rolling process were compared with experimental measurements. This report discusses various attributes of the rolled coupons revealed by the model (e.g., dog-boning and thickness non-uniformity).

  12. FORMATION OF SHAFT SPLINES USING ROLLING METHOD

    M. Sidorenko

    2014-10-01

    Full Text Available The paper describes design of rolling heads used for cold rolling of straight-sided splines on shafts and presents theoretical principles of this process. These principles make it possible to calculate an effort which is required for pushing billet through rolling-on rolls with due account of metal hardening during deformation.

  13. Roll bonding of strained aluminium

    Staun, Jakob M.

    2003-01-01

    This report investigates roll bonding of pre-strained (å ~ 4) aluminium sheets to produce high strain material from high purity aluminium (99.996%) and commercial pure aluminium (99.6%). The degree of bonding is investigated by optical microscopy and ultrasonic scanning. Under the right...... circumstances both materials show good bonding, but the high purity material is excluded because of recrystallisation and the resulting loss of mechanical properties. The effect of cross stacking and roll bonding pre-strained sheets of the commercial purity material is investigated and some dependence of the...... cross rolled volume fraction is found. To further asses this effect, and the anisotropy, it is necessary to acquire knowledge about both texture and microstructure, e.g. by TEM. Roll bonding of pre-strained aluminium is found to be a possible alternative to ARB in the quest for ultra-fine grained...

  14. Numerical analysis of cross shear plate rolling

    Zhang, Wenqi; Bay, Niels

    1997-01-01

    shear zone between the forward and backward slip zones in the deformation zone thus lowering the rolling load. A numerical analysis of the cross shear rolling process is carried out based on the slab method adopting Wanheim and Bay's general friction model. The pressure distribution along the contact......The rolling process is widely applied for industrial production of metal plates. In conventional plate rolling the two work rolls are rotating at the same peripheral speed. By introducing a specific difference in the speed of the two work rolls, cross shear rolling is introduced forming a central...... are in the roll gap, the position and the size of the shear zone and the rolling load are calculated. Experimental results are presented verifying the calculations. The numerical analysis facilitates a better understanding of the mechanics in cross shear plate rolling....

  15. Grease lubrication in rolling bearings

    Lugt, Piet M

    2012-01-01

    The definitive book on the science of grease lubrication for roller and needle bearings in industrial and vehicle engineering. Grease Lubrication in Rolling Bearings provides an overview of the existing knowledge on the various aspects of grease lubrication (including lubrication systems) and the state of the art models that exist today. The book reviews the physical and chemical aspects of grease lubrication, primarily directed towards lubrication of rolling bearings. The first part of the book covers grease composition, properties and rheology, including thermal

  16. Effects of hot-rolling temperature and reduction ratio on edge cracking of hot-rolled boron-stainless steel

    The effects of hot-rolling temperature and reduction ratio on edge cracking in hot-rolled stainless steel containing 1.1% boron were investigated by using a hot-mill simulator. The main results are as follows: (1) The temperature at the side of hot-rolled steel sheets (Ts) during hot-rolling was significantly lower than at the center of hot-rolled steel sheets (Tp) just before hot rolling. (2) Ts at the start of edge cracking was not constant and increased with increasing reduction per pass. (3) The total reduction until the start of edge cracking was constant and was not dependent on Ts or the reduction per pass. (4) It is concluded that total reduction is the main factor in edge cracking due to rapid work hardening of the matrix (γphase), and owing to cavities occurring at the interface of the matrix and boride under constant strain conditions. (author)

  17. Studying possibilities to improve the functional properties of metallurgical rolls

    Z. Stradomski; A. Pirek; Stachura, S

    2008-01-01

    Thc paper prcscnts rcsults nT invcst igations and at~thors' opinion on improving functional propcrtics of mciall urgicnl rolls cast fromGZOOCrMoNi 4-9-3 cast wccl. onc nf most oftcn ilscd lor rolls in scction mills. Thcsc mills Icn~urcq uickcr than flat rolls wear or 1001'spass. whar rcquircs morc Crcqocnt rcpcncr;lt ion. 'Thc machining rcquircs n rclat ivcly low hardness, which is cnsurcd hy ~ h pcc arliiic matrixof casr steel strldid. 7 % ~au thors silggcst 10 achicvc thc optimisntion o f t...

  18. Research on Computer Control of Process Optimization Level in Hydraulic AGC System of Cold Rolling Mill%冷带轧机液压AGC系统过程优化级计算机控制

    孙孟辉; 王益群

    2015-01-01

    冷带轧机的轧制过程是较为复杂的物理过程,因此液压AGC(Automatic Gauge Control)系统对冷带轧机成品带钢的厚度精度起着重要的作用。针对300可逆冷带轧机,进行了过程优化级计算机控制的研究,开发出了液压AGC系统的过程优化级计算机控制系统。液压AGC系统的过程优化级计算机控制,可以实现轧制规程的计算、过程控制级所需设定值的设定、轧制过程数据的采集以及人机界面的显示等功能。同时,进行了轧制试验。%Rolling process of the cold rolling mill is a complicated physical process, so the hydraulic AGC system is very important to the thickness precision of strips of cold rolling mill. In this paper, the computer control of process optimization level was researched, and the computer control system of process optimization level was developed, aiming at 300 reverse cold rolling mill. By the computer control of process optimization level of the hydraulic AGC, it can realize the calculation of rolling schedule, the set of setting value needed by the process control level, the data acquisition of rolling process and the display of human-computer interface. At the same time, the rolling experiment was carried out, and the experiment result implied that it could eliminate the thickness error of strips effectively, adopting the provided computer control's strategy of the process optimization level.

  19. Study on the Microstructure and Texture of 3003 Aluminum Sheets Rolled by Laser-Textured Roll

    Huajun Zhang; Zesheng Ji; Chunbo Cai; Guojun Wang

    2009-01-01

    In order to improve the surface quality and formability of 3003 aluminum alloy sheet, laser-textured rolls are used in cold rolling. The influences of the cold rolling procedures with conventional and laser-textured rolls on the evolution of microstructure and texture were studied by the means of microstructural observations and X-ray texture analysis. Experimental results show that the microstructures are similar besides the samples rolled with laser-textured rolls containing a relatively la...

  20. Characterization of roll bite heat transfers in hot steel strip rolling and their influence on roll thermal fatigue degradation

    Legrand, Nicolas; WEISZ-PATRAULT, Daniel; Horsky, Jaroslav; Luks, Tomas; LABBE, Nathalie; Picard, Michel; Ehrlacher, Alain

    2013-01-01

    A temperature sensor with a thermocouple placed at ~0.5 mm from roll surface is used in hot rolling conditions to evaluate by inverse calculation heat transfers in the roll bite. Simulation analysis under industrial hot rolling conditions with short contact lengths (e.g. short contact times) and high rolling speeds (7 m./s) show that the temperature sensor + inverse analysis with a high acquisition frequency (> 1000 Hz) is capable to predict accurately (5 to 10% error) the roll bite peak of t...

  1. Application research of ferrous matrix composites in roller ring used in high-speed wire/bar rolling mill

    Research highlights: → A composite structure roller rings was fabricated by centrifugal casting. → The roller rings consisted of outer WCP/Fe-C composites layer and inner Fe-C alloy matrix. → Hardness attained to HRA80-85 in the composites layer, and HRA73-76 in inner Fe-C alloy matrix where the toughness was over 8 J/cm2. → The wear resistance of the roller rings excelled that of high-speed steel, and approached to that of the WC hard alloy roll. → The production cost of the WCP/Fe-C composites roller ring decreased by 50%. - Abstract: Tungsten carbide particle (WCP) reinforced ferrous matrix composites roller rings were fabricated by centrifugal casting. The microstructures, properties and application effect of the composites roller rings were investigated by SEM, TEM and various property testers. The experimental results show that the WCP were uniformly distributed in outer reinforced-layer (working-layer) of 20-50 mm in thickness and their volume fraction reached 60-80 vol.%; there was a good interface bonding between WCP and Fe-C alloy without any reaction products; hardness attained to HRA80-85 in working-layer, and HRA73-76 in inner ferrous matrix where the toughness was over 8 J/cm2; the wear resistance of the composites roller rings excels that of high-speed steel; service life of the composites parts approached to that of the WC hard alloy roll when the same WCP-volume-fraction in working-layer were obtained for both of them, but the production cost of the WCP/Fe-C composites roller ring decreased by 50%.

  2. Study on strip-flatness feedforward modelof four cold rolling mill%四辊冷轧机板形前馈模型的研究

    郝亮; 邸洪双; 龚殿尧

    2011-01-01

    The strip-flatness feedforward model with bending force compensation is investigated for four-roll cold rolling mill. With Abaqus finite element software, the parameters of strip-flatness feedforward model were simulated, and the effect of roUing force fluctuation and roUing force on the stripflatness feedforward model was analyzed. The comparison between calculation results and setup parameters shows that both values are consistent.%针对四辊冷连轧轧机,研究了采用工作辊弯辊力补偿的板形前馈模型.用Abaqus有限元软件模拟板形前馈模型参数,分析了轧制力波动量、轧制力对板形前馈模型的影响.对比了板形前馈模型有限元计算值和设定值,对比发现吻合较好.本文对于带材冷轧板形前馈模型参数设定具有重要意义.

  3. Roll-to-roll manufacturing of electronic devices

    Morrison, N. A.; Stolley, T.; Hermanns, U.; Kroemer, U.; Reus, A.; Lopp, A.; Campo, M.; Landgraf, H.

    2012-03-01

    Roll-to-Roll (R2R) production of thin film based electronic devices (e.g. solar cells, activematrix TFT backplanes & touch screens) combine the advantages of the use of inexpensive, lightweight & flexible substrates with high throughput production. Significant cost reduction opportunities can also be found in terms of processing tool capital cost, utilized substrate area and process gas flow when compared with batch processing systems. Nevertheless, material handling, device patterning and yield issues have limited widespread utilization of R2R manufacturing within the electronics industry.

  4. Rolling Stonesi kinokontsert kannab toorest rokiväge / Maris Meiessaar

    Meiessaar, Maris

    2009-01-01

    Martin Scorsese muusikalisest dokumentaalfilmist "Shine a Light - Valgus peale" (USA-Suurbritannia, 2008), mille keskmes on 2006. a. New Yorgi Beaconi teatris toimunud briti ansambli Rolling Stones kontsert

  5. Roll casting of 5182 aluminium alloy

    Haga, T; M. Mtsuo; D. Kunigo; Hatanaka, Y; R. Nakamuta; H. Watari; S. Kumai

    2009-01-01

    Purpose: of this paper is investigation of the ability of the high speed roll casting of 5182 aluminium alloy. Appropriate twin roll caster to cast the 5182 strip was researched.Design/methodology/approach: Method used in the present study was an unequal diameter twin roll caster and a vertical type high speed twin roll caster equipped with mild steel rolls without parting material.Findings: are that the vertical type high speed twin roll caster was effective to cast 5182 strip at high speed....

  6. Hot rolling of thick uranium molybdenum alloys

    DeMint, Amy L.; Gooch, Jack G.

    2015-11-17

    Disclosed herein are processes for hot rolling billets of uranium that have been alloyed with about ten weight percent molybdenum to produce cold-rollable sheets that are about one hundred mils thick. In certain embodiments, the billets have a thickness of about 7/8 inch or greater. Disclosed processes typically involve a rolling schedule that includes a light rolling pass and at least one medium rolling pass. Processes may also include reheating the rolling stock and using one or more heavy rolling passes, and may include an annealing step.

  7. Rolling Process Modeling Report. Finite-Element Model Validation and Parametric Study on various Rolling Process parameters

    Soulami, Ayoub [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Paxton, Dean M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Burkes, Douglas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-06-15

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum alloy plate-type fuel for high-performance research reactors in the United States. This work supports the U.S. Department of Energy National Nuclear Security Administration’s Office of Material Management and Minimization Reactor Conversion Program. This report documents modeling results of PNNL’s efforts to perform finite-element simulations to predict roll-separating forces for various rolling mill geometries for PNNL, Babcock & Wilcox Co., Y-12 National Security Complex, Los Alamos National Laboratory, and Idaho National Laboratory. The model developed and presented in a previous report has been subjected to further validation study using new sets of experimental data generated from a rolling mill at PNNL. Simulation results of both hot rolling and cold rolling of uranium-10% molybdenum coupons have been compared with experimental results. The model was used to predict roll-separating forces at different temperatures and reductions for five rolling mills within the National Nuclear Security Administration Fuel Fabrication Capability project. This report also presents initial results of a finite-element model microstructure-based approach to study the surface roughness at the interface between zirconium and uranium-10% molybdenum.

  8. Rolling Process Modeling Report. Finite-Element Model Validation and Parametric Study on various Rolling Process parameters

    Pacific Northwest National Laboratory (PNNL) has been investigating manufacturing processes for the uranium-10% molybdenum alloy plate-type fuel for high-performance research reactors in the United States. This work supports the U.S. Department of Energy National Nuclear Security Administration's Office of Material Management and Minimization Reactor Conversion Program. This report documents modeling results of PNNL's efforts to perform finite-element simulations to predict roll-separating forces for various rolling mill geometries for PNNL, Babcock & Wilcox Co., Y-12 National Security Complex, Los Alamos National Laboratory, and Idaho National Laboratory. The model developed and presented in a previous report has been subjected to further validation study using new sets of experimental data generated from a rolling mill at PNNL. Simulation results of both hot rolling and cold rolling of uranium-10% molybdenum coupons have been compared with experimental results. The model was used to predict roll-separating forces at different temperatures and reductions for five rolling mills within the National Nuclear Security Administration Fuel Fabrication Capability project. This report also presents initial results of a finite-element model microstructure-based approach to study the surface roughness at the interface between zirconium and uranium-10% molybdenum.

  9. Overlay welding for corrugating roll

    2006-01-01

    The effects of chemical compositions and microstructures on wearability properties of overlaid corrugating roll were studied, and the factors governing the hardness and the wearability of overlaid layer were explored.The results show that the hardness and wearability of the overlaid layer significantly rise with the increase of the mass fraction of various types of eutectic, but the crack-resistance falls. The chief factor governing the hardness of overlaid layer is the matrix microstructure, especially the amount of austenite; and the second is the amount of carbide. The principal factor governing the wearability of overlaid layer is the amount of special carbide, particularly the amount of eutectic; and the second is the hardness of overlaid layer. Meanwhile, high alloying electrodes may cause the gear-surface hardness of corrugating roll to be higher than 63HRc, and may enhance the wearability of the gear-surface of corrugating roll by a factor of 5.63 and 9.08.

  10. DEFECTS SIMULATION OF ROLLING STRIP

    Rudolf Mišičko

    2009-06-01

    Full Text Available The defects in the continuous casting slabs can be developed or kept down in principle by rolling technology, especially depend to sort, size and distribution of primary defects, as well as used of rolling parameters. Scope of the article is on observation behavior artificial surface and undersurface defects (scores without filler (surface defects and filling by oxides and casting powder (subsurface defects. First phase of hot rolling process have been done by software simulation DEFORM 3D setting to the limited condition for samples with surface defects. Samples of material with low-carbon steel of sizes h x b x l have been chosen and the surface defects shape „U” and „V” of scores have been injected artificially by software. The process of rolling have been simulated on the deformation temperatures 1200°C and 900°C, whereas on the both of this deformation temperatures have been applied amount of deformation 10 and 50 %. With respect to the process of computer simulation, it is not possible to truthful real oxidation condition (physical – chemical process during heat of metal, in the second phase of our investigation have been observed influence of oxides and casting powders inside the scores for a defect behavior in plastic deformation process (hot and cold rolling process in laboratory condition. The basic material was STN steel class 11 375, cladding material was steel on the bases C-Mn-Nb-V. Scores have been filled by scales to get from the heating temperatures (1100°C a 1250°C, varied types of casting powders, if you like mixture of scale and casting powders in the rate 1:4. The joint of the basic and cladding material have been done by peripheral welded joint. Experiment results from both phases are pointed on the evolution of original typology defects in rolling process.

  11. The AGC computer control system of a plate rolling mill%首钢中厚板轧机AGC计算机控制系统

    张殿华; 王君; 李建平; 张其生; 赵胜国; 刘仁辅

    2001-01-01

    介绍了首钢中厚板轧钢厂3340mm中厚板轧机液压AGC系统工艺参数和计算机系统的硬件配置和传感器配置,给出了轧机弹跳模型和液压缸HCC的控制原理和液压缸的系统频率响应特性,描述了本系统所采用的头部锁定AGC和绝对AGC的控制策略,并对支撑辊偏心补偿、油膜厚度补偿等厚度控制补偿方法进行了说明。%Based on the hydraulic AGC modernization project of the Capital Iron and Steel Company 3340mm plate mill, this paper presents the computers system and sensors configuration. The mill stiff model and mill hydraulic cylinder control (HCC) principle and its frequency response performance are given. The lockup AGC and absolute AGC are discussed. At end of this paper, the backup rolls eccentric compensation and oil film compensation and other compensations are presented.

  12. The vibration of rolling discs

    Ferguson, Neil Stuart

    1988-01-01

    The study presented is a fundamental investigation into the vibration of a rolling disc and an analysis of the sound which is then produced by the disc response. In order to characterise the disc's behaviour the free and forced vibration of a thin disc is analysed with the additional conditions which occur in rolling. These conditions include the geometric boundary conditions, the effect of the in-plane load, the change due to rotation of the disc and the effect of contact on the disc which i...

  13. Robust Rudder Roll Damping Control

    Yang, C.

    uncertainty, three controllers with different kind of control schemes are designed by the mixed sensitivity method in Chapter 5. Sea-way simulation results show that each of these controllers have good robust stability and performance. The roll damping reduction is above 35% for all of these controllers. Roll...... reduction of near 70% has been obtained by the cascade controller. Using structured model of uncertainty, a m controller is designed in Chapter 6. The good robust performance has been recognized in the simulation results. It is shown that the m controller has the best robust characteristics with respect to...

  14. A new transducer for roll gap measurements of the roll pressure distribution and the friction condition in cold flat rolling

    Lagergren, Jonas; Wanheim, Tarras; Presz, W.;

    2005-01-01

    Background/purpose The only way to establish the true rolling pressure and the true friction condition in cold rolling is to conduct measurements in the roll bite. A new transducer design is therefore proposed, this to overcome problems in previous measurements in the past 70 years. Method The new...

  15. A new sensor for the evaluation of contact stress by inverse analysis during steel strip rolling

    WEISZ-PATRAULT, Daniel; Ehrlacher, Alain

    2011-01-01

    Knowledge of the contact stress between roll and strip becomes a critical factor in modern, high-speed rolling mills. In this paper, an inverse analytical method is developed to determine the contact stress in the roll gap by measuring the stress tensor with fibre optics at only one point inside the roll. Unlike many inverse methods, no matrix inversion is needed because the very small contact length would lead to ill-conditioned matrices. Iterative methods are also not studied because short ...

  16. Simulation of Rolling Billet in Oval Pass by Explicit Dynamics Elastic-Plastic FEM

    LI Jian-chao; CUI Jian-zhong; MA Yong-lin; WANG Bao-feng

    2004-01-01

    A study on prediction of deformation behavior (rolling force, equilibrium strain, spread) during rolling was accomplished with FE code ANSYS/LS-DYNA. The laboratory experiments were conducted on a two-high mill with roll diameter of 170 mm to approve the results of simulation by explicit dynamics FEM. It was found that there is a good agreement between calculated and experimental data, which means that the shape rolling could be analyzed by means of explicit dynamics FEM.

  17. Development of dissimilar metal transition joint by hot bond rolling

    Metallurgically bonded transition joints which enable to connect reprocessing equipments made of superior corrosion resistant valve metals (Ti-5Ta, Zr or Ti) to stainless steel piping are required for nuclear fuel reprocessing plants. The authors have developed dissimilar transition joints made of stainless steel and Ti-5Ta, Zr or Ti with an insert metal of Ta by the hot bond rolling process of clad bars and clad pipes, using a newly developed mill called 'rotary reduction mill'. This report presents the manufacturing process of dissimilar transition joints produced from the clad pipe with three layers by the hot bond rolling. First, the method of hot bond rolling of clad pipe is proposed. Then, the mechanical and corrosion properties of the dissimilar transition joints are evaluated in detail by carrying out various tests. Finally, the rolling properties in the clad pipe method are discussed. (author)

  18. Recent developments in semiprocessed cold rolled magnetic lamination steel

    Over the past 10 years the magnetic property performance of semi-processed cold rolled magnetic lamination steels in North America have approached those of nonoriented, semi-processed silicon steel. This improvement was accomplished via higher alloy levels in conjunction with hot band annealing. New temper rolling strategies can produce weakly oriented steels tailored to specific applications, such as small transformers used in fluorescent lighting ballasts. Recently, production trials for 0.0138 in product cold rolled on tin mills has been undertaken. Efforts to further improve properties through a better understanding of texture control and via implementation of new production processes, such as thin slab or strip casting, continue

  19. Recent developments in semiprocessed cold rolled magnetic lamination steel

    Hilinski, E. J.

    2006-09-01

    Over the past 10 years the magnetic property performance of semi-processed cold rolled magnetic lamination steels in North America have approached those of nonoriented, semi-processed silicon steel. This improvement was accomplished via higher alloy levels in conjunction with hot band annealing. New temper rolling strategies can produce weakly oriented steels tailored to specific applications, such as small transformers used in fluorescent lighting ballasts. Recently, production trials for 0.0138 in product cold rolled on tin mills has been undertaken. Efforts to further improve properties through a better understanding of texture control and via implementation of new production processes, such as thin slab or strip casting, continue.

  20. Ambient roll-to-roll fabrication of flexible solar cells based on small molecules

    Lin, Yuze; Dam, Henrik Friis; Andersen, Thomas Rieks;

    2013-01-01

    All solution-processed roll-to-roll flexible solar cells based on a starshaped small molecule donor and PCBMacceptor were fabricated by slot-die coating, as the first successful example reported for small molecule roll-to-roll flexible solar cells....

  1. 33 CFR 159.107 - Rolling test.

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Rolling test. 159.107 Section 159... MARINE SANITATION DEVICES Design, Construction, and Testing § 159.107 Rolling test. (a) The device, with... manufacturer in § 159.57. (b) Eighty percent of the rolling action must be approximately 15 degrees on...

  2. 14 CFR 25.349 - Rolling conditions.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rolling conditions. 25.349 Section 25.349... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Flight Maneuver and Gust Conditions § 25.349 Rolling conditions. The airplane must be designed for loads resulting from the rolling conditions specified...

  3. 14 CFR 23.349 - Rolling conditions.

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Rolling conditions. 23.349 Section 23.349... Rolling conditions. The wing and wing bracing must be designed for the following loading conditions: (a..., the rolling accelerations may be obtained by modifying the symmetrical flight conditions in §...

  4. 42 CFR 21.46 - Merit roll.

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Merit roll. 21.46 Section 21.46 Public Health... Appointment § 21.46 Merit roll. Each board appointed pursuant to § 21.30 to consider the qualifications of... Secretary, and, if approved by the Secretary, the report shall constitute a merit roll from which...

  5. Finite Element Modeling of Roll Wear during Cold Asymmetric Sheet Rolling of Aluminum Alloy 5083

    Pesin A.

    2015-01-01

    Full Text Available Since the main purpose of asymmetrical rolling is to impose high shear strains on the sheet, in order to obtain ultrafine grain structure, the friction between the rolls and the sheet has to be kept relatively high. This means that asymmetric rolling is performed with dry rolls. The paper presents a numerical analysis of the roll wear during asymmetric cold rolling of 5083 aluminum alloy. The finite element simulation was used to calculate the amount of roll wear by Usui’s equation. FEM simulations were carried out with using software DEFORM 2D. The influence of the friction coefficient on the roll wear and the material flow was discussed. The sliding velocity, interface pressure and temperature were used to calculate the roll wear. The results of simulation can be used to optimize the asymmetric rolling process to improve surface quality of aluminum sheets.

  6. Improvement of thick sheet rolling technology

    Aimed to increase a good yield in steel plate rolling due to a decrease of the quantity of side scrap some suggestions are made which concern the conditions of steel casting, heating to rolling and slab geometry. The investigations were carried out on steel 3p to determine more precisely the influence of processing procedures on the type and the quantity of rolling defects. A new rather complicated rolling schedule resulted in production of sound plates. Some recommendations are given on specific features of hot rolling technology

  7. 76 FR 34101 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    2011-06-10

    ... COMMISSION Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia Determinations... determines that revocation of the countervailing duty order on hot-rolled flat-rolled carbon-quality steel...-rolled flat-rolled carbon-quality steel products from Brazil and Japan. Background The...

  8. Almost rolling motion: An investigation of rolling grooved cylinders

    Mead, L R; Mead, Lawrence R.; Bentrem, Frank W.

    1998-01-01

    We examine the dynamics of cylinders that are grooved to form N teeth for rolling motion down an inclined plane. The grooved cylinders are experimentally found to reach a terminal velocity. This result can be explained by the inclusion of inelastic processes which occur whenever a tooth hits the surface. The fraction of the angular velocity that is lost during an inelastic collision is phenomenologically found to be proportional to (2*sin^2*pi/N)-(alpha*sin^3*pi/N), and the method of least squares is used to find the constant alpha=0.98. The adjusted theoretical results for the time of rolling as well as for terminal velocity are found to be in good agreement with the experimental results.

  9. Roll-to-roll fabrication of polymer solar cells

    Roar Søndergaard

    2012-01-01

    Full Text Available As the performance in terms of power conversion efficiency and operational stability for polymer and organic solar cells is rapidly approaching the key 10–10 targets (10 % efficiency and 10 years of stability the quest for efficient, scalable, and rational processing methods has begun. The 10–10 targets are being approached through consistent laboratory research efforts, which coupled with early commercial efforts have resulted in a fast moving research field and the dawning of a new industry. We review the roll-to-roll processing techniques required to bring the magnificent 10–10 targets into reality, using quick methods with low environmental impact and low cost. We also highlight some new targets related to processing speed, materials, and environmental impact.

  10. Rolling element fatigue testing of gear materials

    Nahm, A. H.

    1978-01-01

    Rolling element fatigue lives of nine alloys were evaluated in Rolling Contact (RC) rigs. Test conditions included a Hertzian stress at 4,826 MPa (700 ksi), a rolling speed of 6.23 m/sec (245 in/sec.). Tests were run with a Type I oil (MIL-L-7808G) at room temperature. B-10 lives (10% failure rate) of alloys were compared versus reference alloys, VIM-VAR AISI M-50 and VAR AISI 9310. Six case carburizing alloys (AISI 9310, CBS600, CBS1000M, EX00014, Vasco X-2 and EX00053) and three through-hardening alloys (AISI M-50, VascoMax 350 and Vasco Matrix 2 evaluated, showed RCF performance inferior or equivalent to that of AISI 9310 and AISI M-50. It was also found that the effects of vacuum melting processes, different tempering temperatures, freezing cycle during heat treating, shot peening, gold plating and chrome plating employed in the present investigation did not significantly affect RCF life.

  11. Rock'n'rolling

    Rare earths are not particularly hard to find but are extremely difficult to extract and refine. Producing rare-earth alloys is a costly process that involves smelting the minerals in three separate stages at temperatures of more than 1000 deg C. An Australian breakthrough, the ball mill processing technique which can produce alloys in a single step at room temperature is briefly presented. While it is yet to be tested on a commercial scale it is estimated that it could eventually supersede the existing method

  12. Microstructure and texture of asymmetrically rolled aluminium and titanium after deformation and recrystallization

    Wronski, M.; Wierzbanowski, K.; Wronski, S.; Bacroix, B.

    2015-08-01

    Asymmetric rolling is used to modify material properties and to reduce forces and torques applied during deformation. This geometry of deformation is relatively easy to implement on existing industrial rolling mills and it can provide large volumes of a material. The results of the study of microstructure and crystallographic texture in asymmetrically rolled aluminium 6061 and titanium (grade 2) are presented in this work. These characteristics were determined using the EBSD technique and X-ray diffraction. The rolling asymmetry was realized using two identical rolls, driven by independent motors, rotating with different angular velocities. It was found that asymmetric rolling leads to microstructural refinement and texture rotation (around the transverse direction). The impact of asymmetric rolling on microstructural refinement appears also in recrystallized samples of both materials. On the other hand, texture rotation, caused by asymmetric rolling, persists after annealing in titanium but not in aluminium samples.

  13. The effect of roll gap geometry on microstructure in cold-rolled aluminum

    Mishin, Oleg; Bay, B.; Winther, G.; Juul Jensen, D.

    2004-01-01

    Microstructure and texture are analyzed through the thickness of two aluminum plates cold-rolled 40% with different roll gap geometries. It is found that both texture and microstructure are strongly affected by the rolling geometry. After rolling with intermediate-size draughts a rolling......-type texture is developed throughout the plate thickness. In this case, grains are subdivided by extended planar dislocation boundaries preferentially aligned at an angle of 40 +/- 15degrees to the rolling direction. In the plate rolled with small draughts, shear texture components appear in the intermediate...... layers. In these layers, extended planar dislocation boundaries are frequently found to be inclined closely to the rolling direction. The subsurface and central layers of this plate exhibit microstructures similar to those in the plate rolled with intermediate draughts. It is suggested that the...

  14. Large-scale Evaluation of Nickel Aluminide Rolls in a Heat-Treat Furnace at Bethelehem Steel's (Now ISG) Burns Harbor Plate Mill

    Mengel, J.

    2003-12-16

    At Bethlehem Steel Burns Harbor Plate Division (now ISG Burns Harbor Plate Inc.)'s annealing furnace, new nickel aluminide intermetallic alloy rolls provide greater high-temperature strength and wear resistance compared to the conventional H series cast austenitic alloys currently used in the industry. Oak Ridge National Laboratory and Bethlehem (ISG) partnered under a U.S. Department of Energy, Office of Industrial Technology's Emerging Technology Deployment Program to demonstrate and evaluate the nickel aluminide intermetallic alloy rolls as part of an updated energy efficient large commercial annealing furnace system. Many challenges were involved in this project, including developing welding procedures for joining nickel aluminide intermetallic alloys with H-series austenitic alloys, developing commercial cast roll manufacturing specifications, working with several commercial suppliers to produce a quantity of high quality, reproducible nickel aluminide rolls for a large steel industrial annealing furnace, installing and demonstrating the capability of the rolls in this furnace, performing processing trials to evaluate the benefits of new equipment and processes, and documenting the findings. Updated furnace equipment including twenty-five new automated furnace control dampers have been installed replacing older design, less effective units. These dampers, along with upgraded flame-safety control equipment and new AC motors and roll-speed control equipment, are providing improved furnace control and additional energy efficiency. Energy data shows up to a 34% energy reduction from baseline after the installation of upgraded furnace damper controls along with up to a 34% reduction in greenhouse gases, potential for an additional 3 to 6% energy reduction per campaign of light-up and shutdown, and a 46% energy reduction from baseline for limited trials of a combination of improved damper control and straight-through plate processing. The straight

  15. Rolling Cylinder Phase 1bis

    Margheritini, Lucia

    This report has been prepared under the contract agreement between Aalborg Universitet and Storper Innovation ApS. The report has been written by Lucia Margheritini (lm@civil.aau.dk) who is also responsible for the data analysis. This report is the continuation of the previous report “Rolling...... Cylinder Phase 1: proof of concept and first optimization”, DCE report 115, ISSN 1901-726X, and it is recommended that the two are consulted together as they were firstly agreed to be in one document. The present report aims at estimate the efficiency of the Rolling Cylinder long model (previously...... optimized), by mean of physical tests in irregular waves. Several difficulties have been encountered during the testing, the biggest of witch being the extremely unfriendly torque measuring system....

  16. FE SIMULATION OF CENTER CRACK OCCURRENCE IN TUBE ROUNDS DURING TWO-ROLL ROTARY ROLLING PROCESS

    S.Z. Li; J. Xu; Y.D. Yin; J.G. Xue; F. Pan; J.M. Zheng; J.H. Yoon

    2007-01-01

    With the aid of FE(finite element) code MSC.Superform 2005, 2-D coupled thermo-mechanical simulation of center-crack occurrence in round billet during 2-roll rotary rolling process was presented using Oyane ductile fracture criteria. A simple modeling is put forward based on the spiral motion of the workpiece as an essential characteristic in movement. The influence of the feed angle and the entry cone angle of the main roll on the process was taken into account in the modeling. The soundness for simplifying the 3-D rotary rolling into a 2-D problem was discussed. By adopting the parameters of Diescher piercer in 140mm mandrel mill of Bao Steel, the distribution and development of strain/stress were analyzed, and the eigen value of ductile fracture as well. The critical percentage of diameter reduction was obtained from the simulation. The result showed a good agreement with the experimental value, and therefore was of widely guiding significance to the practical process for rationally formulating the deformation parameters of steel tube piercing.

  17. Rolling Contact Fatigue of Ceramics

    Wereszczak, Andrew A [ORNL; Wang, W. [Bournemouth University, Bournemouth, United Kingdom; Wang, Y. [Bournemouth University, Bournemouth, United Kingdom; Hadfield, M. [Bournemouth University, Bournemouth, United Kingdom; Kanematsu, W. [National Institute of Advanced Industrial Science and Technology, Japan; Kirkland, Timothy Philip [ORNL; Jadaan, Osama M. [University of Wisconsin, Platteville

    2006-09-01

    High hardness, low coefficient of thermal expansion and high temperature capability are properties also suited to rolling element materials. Silicon nitride (Si{sub 3}N{sub 4}) has been found to have a good combination of properties suitable for these applications. However, much is still not known about rolling contact fatigue (RCF) behavior, which is fundamental information to assess the lifetime of the material. Additionally, there are several test techniques that are employed internationally whose measured RCF performances are often irreconcilable. Due to the lack of such information, some concern for the reliability of ceramic bearings still remains. This report surveys a variety of topics pertaining to RCF. Surface defects (cracks) in Si{sub 3}N{sub 4} and their propagation during RCF are discussed. Five methods to measure RCF are then briefly overviewed. Spalling, delamination, and rolling contact wear are discussed. Lastly, methods to destructively (e.g., C-sphere flexure strength testing) and non-destructively identify potential RCF-limiting flaws in Si{sub 3}N{sub 4} balls are described.

  18. Adaptive Automatic Gauge Control of a Cold Strip Rolling Process

    ROMAN, N.

    2010-02-01

    Full Text Available The paper tackles with thickness control structure of the cold rolled strips. This structure is based on the rolls position control of a reversible quarto rolling mill. The main feature of the system proposed in the paper consists in the compensation of the errors introduced by the deficient dynamics of the hydraulic servo-system used for the rolls positioning, by means of a dynamic compensator that approximates the inverse system of the servo-system. Because the servo-system is considered variant over time, an on-line identification of the servo-system and parameter adapting of the compensator are achieved. The results obtained by numerical simulation are presented together with the data taken from real process. These results illustrate the efficiency of the proposed solutions.

  19. Calucaltion of waste heat from hot rolled steel coils at SSAB and its recovery

    Yousaf, Naeem

    2009-01-01

    Hot rolling process is heat input process. The heat energy in hot rolled steel coils can be utilized. At SSAB Strip Product Borlänge when the hot rolled steel coils came out of the hot rolling mill they are at the temperature range of 500°C to 800°C. Heat energy contained by the one hot rolled steel coil is about 1981Kwh whereas the total heat energy for the year 2008 is 230 GWh/year.The potential of heat is too much but the heat dissipation rate is too slow. Different factors on which heat ...

  20. Adsorption of single-strand alkylammonium salts on bentonite, surface properties of the modified clay and polymer nanocomposites formation by a two-roll mill

    The adsorption of tallow alkylammonium salts onto bentonite from the Lopburi province in Thailand, and the effect of surface wettability on the formation of polymer-clay nanocomposites are reported. We looked specifically at octadecyltrimethyl ammonium chloride (S18), a popular member of the tallow alkylammonium salt family. The adsorption of S18 onto the bentonite interlayer can be divided into three distinct stages depending upon the initial concentration of S18. These stages are (a) monolayer formation, (b) intermediate state of double layer formation and (c) double layer formation. A decrease in surface energy driven by drops in the values of the polar and dispersive components was observed as the amount of surfactant surface coverage increased. Using thermal gravimetric analysis (TGA), the critical surface energy (CSE) of organoclay was found to decrease as the amount of absorbed S18 increased. S18 organoclay with different degrees of surface coverage was used in a two-roll mill to prepare high-density polyetheylene (HDPE)-clay nanocomposites. The oxidized polyethylene wax (OWax) was used as a dispersing agent to promote the delamination of the organoclay platelets. The results from X-ray diffraction (XRD) and transmission electron microscope (TEM) indicated a difference in the dispersing capability of the organoclay.

  1. Assessment of air pollution and its effects on the health status of the workers in beam rolling mills factory (Iran National Steel Industrial Group from Ahvaz-Iran

    Rafiei Masoud

    2009-01-01

    Full Text Available Background: Air pollutants of iron- and steel-making operations have historically been an environmental and health hazard. These pollutants include gaseous substances such as sulfur oxide, nitrogen dioxide, and carbon monoxide. The Iran National Steel Industrial Group beam rolling mills factory has two production lines viz. line 630 and line 650, with different beam production capabilities and is capable of producing different types of beams. Materials and Methods: A retrospective cross-sectional study on 400 workers in different exposure levels to environmental pollution was performed during 2005 to determine the mean value of respirable particulate matter (RPM concentrations and its effects on the health status of workers. To elicit information regarding the health status of the worker, the National Institute for Occupational Safety and Health standard questionnaire was used. Fisher′s exact test was performed to assess the relative risk (RR of exposure to air pollution on cardiovascular diseases, chest tightness, cough, difficulty in retention, i.e. loss of memory, tension, occupational fatigue, and occupational stress in exposed workers. Results: There was significant difference in RPM pollution level between two product lines. The RR of exposure to air pollution on cardiovascular diseases, chest tightness, cough, difficulty in retention, i.e. loss of memory, tension, occupational fatigue, and occupational stress in exposed workers were 2.78, 2.44, 2.15, 1.92, 1.57, 3.90, and 2.09, respectively.

  2. 基于MATLAB的轧机液压压下系统仿真分析%Simulation Analysis of Rolling Mill Hydraulic Press Down System Based on MATLAB

    东鑫渊; 魏秀岭

    2016-01-01

    本文以轧机液压压下控制系统为研究对象,研究其电液位置伺服系统。首先建立电液位置伺服系统数学模型,通过静态计算确定各元件参数和传递函数来拟定系统工作原理方块图。其次运用MATLAB对系统进行动态仿真,分析系统的各个动态品质。%The subjects of study for hydraulic automatic gauge control system in a rolling mill and its electro hydraulic position servo system. Firstly, the mathematical model of electro hydraulic position servo system is established, and the parameters and transfer function of each component are determined by static calculation. Secondly, the dynamic simulation of the system is carried out by using MATLAB, and the dynamic quality of the system is analyzed.

  3. Efficient Circulation of Railway Rolling Stock

    Alfieri, Arianna; Groot, Rutger; Kroon, Leo; Schrijver, Lex

    2002-01-01

    textabstractRailway rolling stock (locomotives, carriages, and train units) is one of the most significant cost sources for operatorsof passenger trains, both public and private. Rolling stock costsare due to material acquisition, power supply, and material maintenance. The efficient circulation of rolling stock material is therefore one of the objectives pursued. In this paper we focus on the circulation of train units on a single line. In order to utilize the train units on this line in an ...

  4. ROLL OUT THE TALENT : Final project report

    Eerola, Tuomas; Tuominen, Pirjo; Hakkarainen, Riitta-Liisa; Laurikainen, Marja; Mero, Niina

    2014-01-01

    The ROLL OUT THE TALENT project was born out of the desire to recognise and support the strengths of vocational students and to develop new and innovative operating models. ROLL OUT THE TALENT promoted regional cooperation between institutes and companies. The project produced operating and study path models that take into consideration the individual strengths of vocational students and the principles of lifelong learning. This is the final report of the ROLL OUT THE TALENT project, and ...

  5. Nonlinear Modulation of Travelling Rolls in Magnetoconvection

    Matsuba, Ken-ichi; Imai, Kenji; Nozaki, Kazuhiro

    1996-01-01

    Modulational dynamics of oscillatory travelling rolls in magnetoconvection is studied near the onset of a Hopf bifurcation. Using weakly nonlinear analysis, we derive an envelope equation of oscillatory travelling rolls in the plane perpendicular to an ambient vertical magnetic field.The envelope equation is the Davey-Stewartson (DS) equation with complex coefficients, from which we obtain criteria for the modulational (Benjamin-Feir) instability of oscillatory travelling rolls.

  6. Designing Imprint Rolls for Fluid Pathway Fabrication

    Vijayaraghavan, Athulan; Dornfeld, David A

    2007-01-01

    This paper discusses a novel method for designing imprint rolls for the fabrication of fluid pathways. Roller imprint processes have applications in diverse areas including fuel cell manufacturing and microfluidic device fabrication. Robust design methods are required for developing imprint rolls with optimal features. In the method discussed in this paper, the rolls are designed procedurally with the fluid pathway design given as input. The pathways are decomposed into repeating features (or...

  7. ROLLING CONDITION FOR ROLLERS ALONG CAMS IN COLD DOUBLE-SET MULTI-ROLLER TUBE ROLLING

    1998-01-01

    The necessary condition of pure rolling for the rollers moving along its individual cams are obtained by the analysis of the loading status of the rollers and it provides a theoretical basis for adjustment of rolling stand.

  8. Large-area, continuous roll-to-roll nanoimprinting with PFPE composite molds

    Successful implementation of a high-speed roll-to-roll nanoimprinting technique for continuous manufacturing of electronic devices has been hindered due to lack of simple substrate preparation steps, as well as lack of durable and long lasting molds that can faithfully replicate nanofeatures with high fidelity over hundreds of imprinting cycles. In this work, we demonstrate large-area high-speed continuous roll-to-roll nanoimprinting of 1D and 2D micron to sub-100 nm features on flexible substrate using perfluoropolyether (PFPE) composite molds on a custom designed roll-to-roll nanoimprinter. The efficiency and reliability of the PFPE based mold for the dynamic roll-to-roll patterning process was investigated. The PFPE composite mold replicated nanofeatures with high fidelity and maintained superb mold performance in terms of dimensional integrity of the nanofeatures, nearly defect free pattern transfer and exceptional mold recovering capability throughout hundreds of imprinting cycles. (paper)

  9. Image Mosaicing Algorithm for Rolled Fingerprint Construction

    贺迪; 荣钢; 周杰

    2002-01-01

    Fingerprint identification is one of the most important biometric authentication methods. However, current devices for recording digital fingerprints can only capture plain-touch fingerprints. Rolled fingerprints have much more information for recognition, so a method is needed to construct a rolled fingerprint from a series of plain-touch fingerprints. This paper presents a novel algorithm for image mosaicing for real time rolled fingerprint construction in which the images are assembled with corrections to create a smooth, non-fragmented rolled fingerprint in real time. Experimental results demonstrate its effectiveness by comparing it with other conventional algorithms.

  10. Role of Friction in Cold Ring Rolling

    He YANG; Lianggang GUO; Mei ZHAN

    2005-01-01

    Cold ring rolling is an advanced but complex metal forming process under coupled effects with multi-factors, such as geometry sizes of rolls and ring blank, material, forming process parameters and friction, etc. Among these factors,friction between rolls and ring blank plays animportant role in keeping the stable forming of cold ring rolling. An analytical method was firstly presented for proximately determining the critical friction coefficient of stable forming and then a method was proposed to determine thecritical friction coefficient by combining analytical method with numerical simulation. And the influence of friction coefficient on the quality of end-plane and side spread of ring,rolling force, rolling moment and metal flow characteristic in the cold ring rolling process have been explored using the three dimensional (3D) numerical simulation based on the elastic-plastic dynamic finite element method (FEM)under the ABAQUS software environment, and the results show that increasing the friction on the contact surfaces between rolls and ring blank is useful not only for improving the stability of cold ring rolling but also for improving the geometry and dimension precision of deformed ring.

  11. Interactions Between Stably Rolling Leukocytes In Vivo

    King, M R; Kim, M B; Sarelius, I H; King, Michael R.; Ruscio, Aimee D.; Kim, Michael B.; Sarelius, Ingrid H.

    2003-01-01

    We have characterized the two-dimensional spatial dependence of the hydrodynamic interactions between two adhesively rolling leukocytes in a live venule in the mouse cremaster muscle. Two rolling leukocytes were observed to slow each other down when rolling together in close proximity, due to mutual sheltering from the external blood flow in the vessel lumen. These results are in agreement with a previous study of leukocyte rolling interactions using carbohydrate-coated beads in a parallel-plate flow chamber and a detailed computer model of adhesion in a multicellular environment.

  12. Rolling-cuff flexible bellows

    Lambert, D.R.

    1982-09-27

    A flexible connector apparatus used to join two stiff non-deformable members, such as piping, is described. The apparatus is provided with one or more flexible sections or assemblies each utilizing a bellows of a rolling cuff type connected between two ridge members, with the bellows being supported by a back-up ring, such that only the curved end sections of the bellows are unsupported. Thus, the bellows can be considered as being of a tube-shaped configuration and thus have high pressure resistance. The components of the flexible apparatus are sealed or welded one to another such that it is fluid tight.

  13. Finite Element Analysis of Symmetric and Asymmetric Three-roll Rolling Process

    Pesin A.

    2015-01-01

    Full Text Available A three-roll process is a significant technique in the production of wire rod, round bars and hexagonal profiles for structural applications. Better mechanical properties of wire rod, round bars and hexagonal profiles can be achieved due to large plastic deformation by the three-roll process. Asymmetric rolling is a novel technique characterised by a kinematic asymmetry linked to the difference in peripheral speed of the rolls, able to introduce additional shear strains through the bar thickness. In order to achieve this, asymmetrical three-roll rolling process was investigated to better control the deformation compared to the conventional three-roll rolling process in a stand with two three-roll calibers located very close to each other. Simulation of round-triangle-triangle pass rolling was performed. FEM simulations were carried out with using software DEFORM 3D. The influence of the friction coefficient and speed asymmetry on the shear strain and material flow was discussed. The results of simulation can be used to optimize the asymmetric three-roll rolling process to improve the mechanical properties of wire rod, round bars and hexagonal profiles.

  14. 75 FR 62566 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    2010-10-12

    ... COMMISSION Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United... countervailing duty order on hot-rolled flat-rolled carbon-quality steel products (``hot-rolled steel'') from... that full reviews pursuant to section 751(c)(5) of the Act should proceed (75 FR 42782, July 22,...

  15. PECULIARITIES OF INFLUENCE OF THERMO-MECHANICAL PROCESSING IN PRODUCTION LINE OF MILL 150 OF THE BELARUSIAN METALLURGICAL WORKS ON QUALITATIVE CHARACTERISTICS OF HIGH-CARBON ROLLED WIRE

    V. A. Lutsenko

    2015-06-01

    Full Text Available Using of new arrangement of finishing train of block structure with divisibility of deformation and system of inter-block control of the semi-finished rolled products temperature enables to decrease disorder of mechanical properties, to reduce the depth of the decarbonized layer.

  16. 76 FR 62894 - Following Procedures When Going Between Rolling Equipment

    2011-10-11

    ... Federal Railroad Administration Following Procedures When Going Between Rolling Equipment AGENCY: Federal... of following procedures when going ] between rolling equipment. This safety advisory contains various... who, in the course of their work, place themselves between rolling equipment. The railroad...

  17. EFFECTS OF CARBON CONTENT AND ROLLING PROCESSING ON RETAINED AUSTENITE FOR HOT-ROLLED TRIP STEELS

    Y. Chen; X. Chen; Z.X. Yuan; B.F. Xu; A.M. Guo; P.H. Li; S.K. Pu

    2002-01-01

    The effects of finishing rolling temperature and coiling temperature on retained austen-ire were studied for hot-rolled transformation induced plasticity (TRIP) steels withdifferent carbon content. The experimental results showed that an appropriate volumefraction of retained austenite from 6% to 11% could be obtained according to the dif-ferent carbon content less than 0.20% by controlled finishing rolling and coiling forthe hot-rolled TRIP steels. It can be concluded that carbon content has a significanteffect on the fraction of retained austenite and coiling processing plays stronger roleon retaining austenite than fishing rolling processing.

  18. Roll forming of eco-friendly stud

    Keum, Y. T.; Lee, S. Y.; Lee, T. H.; Sim, J. K.

    2013-12-01

    In order to manufacture an eco-friendly stud, the sheared pattern is designed by the Taguchi method and expanded by the side rolls. The seven geometrical shape of sheared pattern are considered in the structural and thermal analyses to select the best functional one in terms of the durability and fire resistance of dry wall. For optimizing the size of the sheared pattern chosen, the L9 orthogonal array and smaller-the-better characteristics of the Taguchi method are used. As the roll gap causes forming defects when the upper-and-lower roll type is adopted for expanding the sheared pattern, the side roll type is introduced. The stress and strain distributions obtained by the FEM simulation of roll-forming processes are utilized for the design of expanding process. The expanding process by side rolls shortens the length of expanding process and minimizes the cost of dies. Furthermore, the stud manufactured by expanding the sheared pattern of the web is an eco-friend because of the scrapless roll-forming process. In addition, compared to the conventionally roll-formed stud, the material cost is lessened about 13.6% and the weight is lightened about 15.5%.

  19. Influence of Surge on Extreme Roll Amplitudes

    Vidic-Perunovic, Jelena; Rognebakke, Olav; Pedersen, Preben Terndrup

    2008-01-01

    Interference of the wave-induced ship surge motion with roll dynamics has been studied. The surge motion has been included in a previously derived hydrodynamic roll prediction model in order to account for the ship speed variation due to the longitudinal incident wave pressure force. Depending on...

  20. 9 CFR 381.159 - Poultry rolls.

    2010-01-01

    ....159 Poultry rolls. (a) Binders or extenders may be added in accordance with a regulation in this subchapter, in 9 CFR Chapter III, Subchapter E, or in 21 CFR Chapter I, Subchapter A or Subchapter B. In... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Poultry rolls. 381.159 Section...

  1. CRITICAL WAVE EPISODES FOR ASSESSMENT OF ROLL

    Jensen, Jørgen Juncher; Pedersen, Preben Terndrup

    The statistical distribution of parametric induced roll angles is estimated using the first order reliability method (FORM), well-known from structural reliability problems. To illustrate the proposed procedure the roll motion is modeled by a simplified non-linear procedure taking into account the...

  2. Towards roll-to-roll manufacturing of polymer photonic devices

    Subbaraman, Harish; Lin, Xiaohui; Ling, Tao; Guo, L. Jay; Chen, Ray T.

    2014-03-01

    Traditionally, polymer photonic devices are fabricated using clean-room processes such as photolithography, e-beam lithography, reactive ion etching (RIE) and lift-off methods etc, which leads to long fabrication time, low throughput and high cost. We have utilized a novel process for fabricating polymer photonic devices using a combination of imprinting and ink jet printing methods, which provides high throughput on a variety of rigid and flexible substrates with low cost. We discuss the manufacturing challenges that need to be overcome in order to realize true implementation of roll-to-roll manufacturing of flexible polymer photonic systems. Several metrology and instrumentation challenges involved such as availability of particulate-free high quality substrate, development and implementation of high-speed in-line and off-line inspection and diagnostic tools with adaptive control for patterned and unpatterned material films, development of reliable hardware, etc need to be addressed and overcome in order to realize a successful manufacturing process. Due to extreme resolution requirements compared to print media, the burden of software and hardware tools on the throughput also needs to be carefully determined. Moreover, the effect of web wander and variations in web speed need to accurately be determined in the design of the system hardware and software. In this paper, we show the realization of solutions for few challenges, and utilizing these solutions for developing a high-rate R2R dual stage ink-jet printer that can provide alignment accuracy of polymer photonic systems opens limitless possibilities for the deployment of high performance components in a variety of applications including communication, sensing, medicine, agriculture, energy, lighting etc.

  3. Tensile mechanical behavior and fracture toughness of MWCNT and DWCNT modified vinyl-ester/polyester hybrid nanocomposites produced by 3-roll milling

    This study aims to investigate the tensile mechanical behavior and fracture toughness of vinyl-ester/polyester hybrid nanocomposites containing various types of nanofillers, including multi- and double-walled carbon nanotubes with and without amine functional groups (MWCNTs, DWCNTs, MWCNT-NH2 and DWCNT-NH2). To prepare the resin suspensions, very low contents (0.05, 0.1 and 0.3 wt.%) of carbon nanotubes (CNTs) were dispersed within a specially synthesized styrene-free polyester resin, conducting 3-roll milling technique. The collected resin stuff was subsequently blended with vinyl-ester via mechanical stirring to achieve final suspensions prior to polymerization. Nanocomposites containing MWCNTs and MWCNT-NH2 were found to exhibit higher tensile strength and modulus as well as larger fracture toughness and fracture energy compared to neat hybrid polymer. However, incorporation of similar contents of DWCNTs and DWCNT-NH2 into the hybrid resin did not reflect the same improvement in the corresponding mechanical properties. Furthermore, experimentally measured elastic moduli of the nanocomposites containing DWCNTs, DWCNT-NH2, MWCNTs and MWCNT-NH2 were fitted to Halphin-Tsai model. Regardless of amine functional groups or content of carbon nanotubes, MWCNT modified nanocomposites exhibited better agreement between the predicted and the measured elastic moduli values compared to nanocomposites with DWCNTs. Furthermore, Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used to reveal dispersion state of the carbon nanotubes within the hybrid polymer and to examine the CNT induced failure modes that occurred under mechanical loading, respectively. Based on the experimental findings obtained, it was emphasized that the types of CNTs and presence of amine functional groups on the surface of CNTs affects substantially the chemical interactions at the interface, thus tuning the ultimate mechanical performance of the resulting nanocomposites.

  4. Effect of Pavement Conditions on Rolling Resistance

    Mr.Dipanjan Mukherjee

    2014-07-01

    Full Text Available Rolling resistance is the force acting on a vehicle over a full journey. It is generated by the hysteresis of tyre and pavement. Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body (such as a ball, tire, or wheel rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation (or movement of the wheel, roadbed, etc. is recovered when the pressure is removed. A hysteresis phenomenon can be observed when viscoelastic materials undergo a load-then-unload process. A typical hysteresis curve of viscoelastic material can be found. The shadow area enclosed by the hysteresis loop represents energy loss. A characteristic of a deformable material such that the energy of deformation is greater than the energy of recovery. The rubber compound in a tire exhibits hysteresis. As the tire rotates under the weight of the vehicle, it experiences repeated cycles of deformation and recovery, and it dissipates the hysteresis energy loss as heat. Hysteresis is the main cause of energy loss associated with rolling resistance and is attributed to the viscoelastic characteristics of the rubber. Materials that have a large hysteresis effect, such as rubber, which bounce back slowly, exhibit more rolling resistance than materials with a small hysteresis effect that bounce back more quickly and more completely, such as steel or silica. Low rolling resistance tires typically incorporate silica in place of carbon black in their tread compounds to reduce low-frequency hysteresis without compromising traction. Note that railroads also have hysteresis in the roadbed structure. Like the fuel consumption, rolling resistance also has a significant relationship with velocity. experiment has shown that, for a 32-tonn goods vehicle, rolling resistance contributes about 70% of total drag when driven at 50km/h and about 37% at 100km/h. An important issue which should not

  5. Effect of driver roll rotational speed on hot ring rolling of AZ31 magnesium alloy

    Xiaodong Luo

    2014-06-01

    Full Text Available Based on the ABAQUS/Explicit code, A 3D elastic–plastic and coupled thermo-mechanical FE model of radial ring rolling of AZ31 Magnesium alloy has been proposed to analyze the influence of rotational speed of driver roll to study the inhomogeneity distribution of strain and temperature, fishtail coefficient, rolling force parameters. The results show that: (1 when the rotational speed of driver roll n increases, the strain distribution of the rolled ring becomes less homogeneous, and the temperature distribution more homogeneous yet, and leading to an optimal n value; (2 the fishtail coefficient firstly decreases, then increases with the increase of n; (3 the rolling force, contact area and rolling moment gradually descend with the increase of n.

  6. Computational Analysis of Ares I Roll Control System Jet Interaction Effects on Rolling Moment

    Deere, Karen A.; Pao, S. Paul; Abdol-Hamid, Khaled S.

    2011-01-01

    The computational flow solver USM3D was used to investigate the jet interaction effects from the roll control system on the rolling moment of the Ares I full protuberance configuration at wind tunnel Reynolds numbers. Solutions were computed at freestream Mach numbers from M = 0.5 to M = 5 at the angle of attack 0deg, at the angle of attack 3.5deg for a roll angle of 120deg, and at the angle of attack 7deg for roll angles of 120deg and 210deg. Results indicate that the RoCS housing provided a beneficial jet interaction effect on vehicle rolling moment for M > or = 0.9. Most of the components downstream of the roll control system housing contributed to jet interaction penalties on vehicle rolling moment.

  7. Effect of ultrasonic oscillations on steel rolling

    The effect of radial ultrasonic oscillations on rolling has been studied. Plates and pipes made of the St3 and 08Kh18N10T steel were rolled at 20 and at 1200 deg C. Ultrasonic waves proved to reduce pressure on the rollers by 9-14%, this eventually leading to higher efficiency of rolling. Hot rolling involving ultrasonic treatment decreased the ultrimate strength and yield point of both steels by 5-10% and increased relative elongation on account of uniform contraction. Cold ultrasound-involving rolling decreased the ultimate strength and the yield point of the St3 steel, hardly affecting those of the 08Kh18N10T steel

  8. FORMULAS OF TENSION OF CONTINUOUS ROLLING PROCESS

    J.Z. Zhang; X.P. Zhang

    2007-01-01

    The development of computer controlled continuous rolling process calls for a mathematicalexpression that can express the inequality condition of "constant flow". Tension is the link of thecontinuous rolling process. From the condition of dynamic equilibrium, a differential equation oftension is given out. On the basis of the physical rules established from the industrial practice andexperimental studies, the law of volume constancy, the linear relation of forward slip and tension,the state equation of continuous rolling, the formula of dynamic tension, and the formula of statictension have been obtained. These formulae reflect the functional relations between tensions,thickness, roll velocity, and time in the continuous rolling process. It is implied that the continuousrolling process is a gradually steady, controllable, and measurable dynamic system. An assumptionof predicting the thickness of a steel plate using these tension formulae is also put forward.

  9. Synthesis of metal hydrides by cold rolling

    'Full text:' In the development of metal hydrides for commercial applications, a special attention should be devoted to the ways of production. For commercial success, the raw elements of the hydrogen storage materials should be of low cost, the synthesis process should be inexpensive and easily scalable. Therefore, it is important to put some effort on the elaboration of new and more efficient means of producing metal hydrides. In this perspective, cold rolling was investigated as a new means of producing nanocrystalline materials. This technique is well-known in the industry and easily scalable. Cold rolling was performed on Mg-Ni system. The evolution of morphology, crystal structure, crystallite size, deformation, and preferred orientation was studied as a function of number of rolling passes. Cold rolling followed by a heat treatment produced the intermetallic Mg2Ni. Without heat treatment and for a large number of rolling, an amorphous phase was synthesized. (author)

  10. Automated Procedure for Roll Pass Design

    Lambiase, F.; Langella, A.

    2009-04-01

    The aim of this work has been to develop an automatic roll pass design method, capable of minimizing the number of roll passes. The adoption of artificial intelligence technologies, particularly expert systems, and a hybrid model for the surface profile evaluation of rolled bars, has allowed us to model the search for the minimal sequence with a tree path search. This approach permitted a geometrical optimization of roll passes while allowing automation of the roll pass design process. Moreover, the heuristic nature of the inferential engine contributes a great deal toward reducing search time, thus allowing such a system to be employed for industrial purposes. Finally, this new approach was compared with other recently developed automatic systems to validate and measure possible improvements among them.

  11. The Evolution of the Surface Morphologies and Microstructures of an Unleveled Hot-Rolled Steel Strip During Cold Rolling After Hydrogen Reduction

    Jing, Yu-An; Shang, Qiuyue; Zang, Xiaoming; Zhang, Lei; Peng, Xingdong; Jia, Pinfeng

    2016-01-01

    The removal of oxide scale from a hot-rolled strip surface can completely eliminate environmental pollution if performed by hydrogen-reduction descaling instead of traditional pickling descaling. However, a large number of cracks appear on the surface of a leveled hot-rolled steel strip after hydrogen reduction. This effect is likely to impede the application of reduction descaling to cold-rolled products. Nevertheless, there are almost no cracks on the surface of an unleveled hot-rolled steel strip if the hot-rolled steel strip is not subjected to repeated bending by the leveler machine. The surface quality of a reduced steel strip will be better than that of a pickled steel strip. To investigate the evolution of the surface morphologies, microstructures, and properties of an unleveled strip steel during cold rolling, unleveled strip steel samples were rolled using a four-high mill after hydrogen reduction and after pickling. The surface morphologies and cross-sectional microstructures of the samples were observed by SEM, and the surface-roughness values were measured using a TR200 profilometer before and after cold-rolling deformation. The evolution of the surface morphologies and cross-sectional microstructures of the sample after cold rolling were analyzed. The results show that the oxide scale formed on the surface turns into a metallic iron layer, and a decarburization layer appears between the metallic iron layer and the steel matrix after hydrogen reduction. Few cracks, besides pores, and bubbles, appeared on the surface of the sample after hydrogen reduction. The pores and bubbles were roll-flattened after five passes of cold rolling. The work hardening degree and mechanical properties of the reduced sample are similar to those of the pickled sample after cold rolling. Compared with the rolled sample after pickling, the surface qualities of the reduced samples are better than those of the pickled samples and better than those of the reduced samples that

  12. Modeling and Simulation for Rolling Mill Oil Film Compensate Based on RBF Neural Network%基于RBF的轧机油膜补偿建模与仿真

    张利红; 梁英波; 李晋

    2013-01-01

    为了减小热轧机支撑辊动压油膜轴承油膜厚度变化对带钢出口厚度的影响,提高AGC控制精度,建立了基于RBF神经网络的轧机油膜补偿模型;对某2 500 mm单机架热轧中厚板生产线轧机用空压靠法,得到不同轧辊转速和轧制力条件下的轧辊辊缝值,对模型进行训练,并对模型进行仿真.结果表明:基于RBF神经网络的轧机油膜补偿模型能够在线实时地对热轧中厚板生产线油膜厚度变化进行补偿,对改善中厚板带钢的纵向厚差、提高中厚板带钢成材率具有重要意义.%In order to reduce the impact of change of oil film thickness on strip export thickness in dynamic oil film bearing of backup roller and improve the AGC precision,the model of rolling mill oil film compensate was established based on RBF neural network.Using emptypressure methods to a 2 500 mm single-stand hot strip rolling mill,the roller seam values under different roll speed and rolling force were gotten.The model was trained and simulated.The simulation results show that oil film compensate model based on RBF neural network can be used to online real-time compensate oil film thickness changes of hot plate production line.It is important to improve the longitudinal thickness difference of the strip and to increase yield rate of the plate.

  13. Vibrations of a rolling tyre

    Kozhevnikov, I. F.

    2012-03-01

    We investigate vibrations of an unloaded and loaded tyre rolling at constant speed without slipping in the contact area. A previously proposed analytical model of a reinforced tyre is considered. The surface of the tyre is represented by flexible tread, combined with parts of two tori (sidewalls of the tyre). The contact between the wheel and the ground plane occurs by the part of the tread. The natural frequencies (NF) and mode shapes (MS) are determined analytically for unloaded tyre and numerically for loaded tyre. The results were compared with experiments for the non-rotating tyre. In the case of loaded rotating tyre, the increasing of the angular velocity of rotation implies that NF decrease. Moreover, a phenomenon of frequency loci veering is visible here: NF as functions of angular velocity approach each other and then veer away instead of crossing. The MS interact in veering region and, as a result, interchange.

  14. Experimental study of interfacial heat flux and surface temperature by inverse analysis with thermocouple (fully embedded) during hot steel strip rolling

    WEISZ-PATRAULT, Daniel; Ehrlacher, Alain; Legrand, Nicolas; LABBE, Nathalie; Horsky, Jaroslav; Luks, Tomas

    2012-01-01

    Knowledge of temperature distribution in the roll is fundamental aspect in cold rolling. An inverse analytical method has been previously developed to determine interfacial heat flux and surface temperature by measuring the temperature with a thermocouple (fully embedded) at only one point inside the roll. On this basis some pilot mill tests have been performed. The temperature sensor, the calibration procedure and rolling tests at different strip rolling conditions (5%, 10%, 15% and 20%) are...

  15. Off-line calculation of pass schedule for hot rolling stainless steel strip and establishment of model parameters for on-line set up calculation

    In this paper, the method to calculate the roughing and finishing rolling forces is described. The way to establish the model parameters for on-line process set up calculation during developing hot rolling stainless steel strip in 2050mm hot rolling mill of Baosteel, is also introduced. Rolling test shows that the rolling forces calculated by on-line process set up model agree well with measured data. (author)

  16. Flow Stress Evaluation in Hot Rolling of Steel

    Aghasafari, P.; Salimi, M.; Daraei, A.

    2014-08-01

    In this paper, an inverse analysis technique is used to obtain the flow curve of materials in a hot rolling finishing mill. This technique is based on minimization of the differences between the experimental and computed values. The flow curves and the friction coefficients at roll/work-piece interface are derived from two different models. Model I is based on simple slab method of analysis. Model II is based on a modified slab method in which the effect of shear stress in calculating the rolling force and torque is taken into account. It is shown that the developed inverse analysis technique is reliable and can simultaneously determine a more accurate flow stress for the material as well as a better estimation for the interface friction factors.

  17. Austempering of hot rolled transformation-induced plasticity steels

    Zhuang Li; Di Wu

    2008-01-01

    Thermomechanical controlled processing (TMCP) was conducted by using a laboratory hot rolling mill. Austempering inAustempering in the salt bath after hot rolling Was investigated. The effect of isothermal holding time on mechanical properties was studied throughing of the microstructure and mechanical properties of the specimens. The mechanism of transformation-induced plasticity (TRIP) was discussed. The results show that the microstructure of these steels consists of polygonal ferrite, granular bainite, and ad TRIP occur in the hot rolled Si-Mn TRIP steels. Excellent mechanical properties were obtained for various durations at 400℃. Prolonged holdingprecipitation, which destabilized the austenite. The mechanical properties were optimal when the specimen was held for 25 min, and the tensile strength, total elongation, and strength ductility balance reached the maximum values of 776 MPa, 33%,respevtively.

  18. High speed roll casting of Mg alloy strip by a vertical type twin roll caster

    H. Watari

    2006-02-01

    Full Text Available Purpose: The possibility of high speed roll casting of AZ31, AM60 and AZ91 was investigated. Warm deep drawing of roll cast magnesium alloy was operated. and formability of roll cast magnesium strip was cleared.Design/methodology/approach: A vertical type high speed twin roll caster was used. The roll casting was operated in the air atmosphere. The casting speed was from 60 m/min up to 180 m/min. Low temperature casting was adopted to realize high speed casting.Findings: Strip thinner 3 mm with 100 width could be cast continuously. The casting ability became better with increasing content of Al. Roll cast Mg alloy strips could be hot-rolled down to 0.5 mm. AZ31 as-cast strip could be thinner down to 0.5 mm only by three times of hot rolling. Deep drawing was operated with three kinds of Mg alloy at 250°C, and LDR value was larger than 2.0. It was shown that deep drawing of AZ91 alloy for casting was possible.Research limitations/implications: There was tendency that cracks occurred at the center in the thickness direction as Al content increased.Practical implications: Sheet metal forming of magnesium alloy with high content Al can be realized.Originality/value: It was shown that possibility of high speed roll casting of magnesium alloy, and warm deep drawing of roll cast AZ91 strip.

  19. Wheelchair tire rolling resistance and fatigue.

    Kauzlarich, J J; Thacker, J G

    1985-07-01

    The hysteresis loss theory of rolling resistance is developed for solid rubber wheelchair tires. The analysis is used to correlate test data for a clay-filled natural rubber and a polyurethane tire material. A discussion of tire rolling work, hysteresis loss factor measurement, and rolling loss measurement is presented. An example calculation of rolling resistance for a polyurethane tire is given in detail. The subject of solid rubber tire design is developed on the basis of recommended fatigue life theory and practice. It is shown that polyurethane tires have a useful fatigue life due to a high shear modulus at useful values of hardness. This characteristic of polyurethane, if exploited, is predicted to lead to a tire with a lower rolling resistance than other wheelchair tires available. The effect of surface roughness on rolling resistance is briefly discussed and some experimental results are listed. The purpose of this paper is to give the rehabilitation engineer the means for wheelchair tire rolling resistance and fatigue life design and the methods to assess the tire characteristics when a tire design is modified or a new tire material is contemplated. Other important design factors, such as wear and chemical degradation, are not discussed, but references are suggested for information on these topics. As in most research and development projects, this study raises problems which need further work. For example, the fatigue properties of the rubber compounds employed in this application are not completely understood; this subject is planned for future investigation. PMID:3835263

  20. 冷连轧机负荷分配多目标优化计算方法%Multi-objective optimization calculation method of load distribution of cold tandem rolling mill

    金耀辉; 王军生; 宋君; 王奎越; 刘宝权; 吴萌

    2015-01-01

    Considering the equipment ability,mill production,and product quality,the multi-objective function of load distribution of the cold tandem rolling mill is established according to the rolling force,plate shape screwdown ratio,power,and tension. The constraint optimization problem is conver-ted into the unconstraint optimization problem through introducing a penalty term. This optimization method is composed of two phases.β factor theory is used to solve the nonlinear equations in the ini-tialization phase. And the Nelder-Mead simplex method is used to solve the multi-objective function in the optimization phase. This load distribution calculation method has been successfully applied in the process control system of a 5-stand cold tandem rolling mill,and the control effect is good.%在综合考虑设备能力、轧机产量和产品质量的基础上,建立了基于轧制力、板形、压下率、功率及张力的冷连轧机负荷分配多目标函数。通过引入惩罚项,将约束优化问题转化为无约束优化问题来求解。采用两阶段计算方法,初始阶段采用β因子理论方法求解非线性方程组,优化阶段采用Nelder-Mead单纯形法求解多目标函数。此负荷分配计算方法已成功应用于某五机架冷连轧机组的过程控制系统,效果较好。

  1. PHYSICAL SIMULATION OF CONTINUOUS ROLL CASTING PROCESS

    L.H. Zhan; J. Zhong; X.Q. Li; M.H. Huang

    2005-01-01

    A series of simulating experimental studies on the rheological behavior and its influential factors of aluminum alloy in continuous roll-casting process have been explored in this paper with a Gleeble-1500 Thermal-Mechanical Simulation Tester and a set of special clamp system. Relevant rheological rules in the process of coupling transient solidification and continuous deformation of roll-casting conditions are obtained. Experimental results indicate that four different characteristic stages exist in the whole rheological process, and relative constitutive models suitable for the given conditions of continuous roll casting process have been established through multivariable linear regression analysis of the experimental data.

  2. Rolling process for producing biaxially textured substrates

    Goyal, Amit

    2004-05-25

    A method of preparing a biaxially textured article includes the steps of: rolling a metal preform while applying shear force thereto to form as-rolled biaxially textured substrate having an a rotated cube texture wherein a (100) cube face thereof is parallel to a surface of said substrate, and wherein a [100] direction thereof is at an angle of at least 30.degree. relative to the rolling direction; and depositing onto the surface of the biaxially textured substrate at least one epitaxial layer of another material to form a biaxially textured article.

  3. Prediction of Rolling Load, Recrystallization Kinetics, and Microstructure During Hot Strip Rolling

    2007-01-01

    The recrystallization kinetics and grain size models were developed for the C-Mn and niobium-containing steels to describe the metallurgical phenomenon such as softening, grain growth, and strain accumulation. Based on the recrystallization kinetics equations, the mean flow stress and the rolling load of each pass were predicted and the optimum rolling schedule was proposed for hot strip rolling. The austenite grain refinement is associated with the addition of niobium, the decrease of starting temperature of finish rolling, and the reduction of finished thickness. The mean flow stress curve with a continuous rising characteristic can be usually observed in the finish rolling of niobiumcontaining steel, which is formed as a result of the heavy incomplete softening and strain accumulation. The predicted rolling loads are in good agreement with the measured ones.

  4. Numerical Analysis of a Rolling Process for Producing Steel Balls Using Helical Rolls

    Chyła P.

    2016-06-01

    Full Text Available This paper presents the research results of the balls rolling process according to the conventional and modified methods of rolling. Theoretical analysis was carried out by using numerical methods based on the Finite Element Method. The Simufact package version 10.0 were used for calculation. Simulations of balls rolling were carried out under conditions of 3D state of strain, taking into account the effect of thermal conditions occurring during forming. The study of the achieved results showed that the best rolling process parameters were obtained for the modified method, in which the feed material is heated up to 1150 °C. In this case, the rolling parameters such as: rolling force and torque as well as tool wear reached the smallest values.

  5. 21 CFR 136.115 - Enriched bread, rolls, and buns.

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Enriched bread, rolls, and buns. 136.115 Section... § 136.115 Enriched bread, rolls, and buns. (a) Each of the foods enriched bread, enriched rolls, and... label statement of ingredients prescribed for bread, rolls or buns by § 136.110, except that: (1)...

  6. 21 CFR 136.130 - Milk bread, rolls, and buns.

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Milk bread, rolls, and buns. 136.130 Section 136....130 Milk bread, rolls, and buns. (a) Each of the foods milk bread, milk rolls, and milk buns conforms... ingredients prescribed for bread, rolls or buns by § 136.110 except that: (1) The only moistening...

  7. 21 CFR 136.160 - Raisin bread, rolls, and buns.

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Raisin bread, rolls, and buns. 136.160 Section 136....160 Raisin bread, rolls, and buns. (a) Each of the foods raisin bread, raisin rolls, and raisin buns... of ingredients prescribed for bread, rolls or buns by § 136.110, except that: (1) Not less than...

  8. Transparent conductive film by large area roll-to-roll processing

    Sputtered indium tin oxide (ITO) coating on polyethylene terephthalate film has been used as the substrate for roll-to-roll fabrication of large area printed electronics devices, but it is expensive and could be cracked when bending, limiting its applications. Transparent conductive (TC) electrode made by roll-to-roll coating of transparent conductive ink on flexible substrate is an alternative, but both the ink material and the control of the coating quality are very crucial. The major challenges are the coating performance, coating uniformity and defect control during roll-to-roll processing. In this paper, we report the chemical synthesis of silver nanowires in preferred shape and size, the surface modification of the Ag nanowires for better dispersion into the commercial Poly(3,4-ethylenedioxythiophene) Poly(styrenesulfonate) (PEDOT:PSS) conductive polymer ink, and the controlled roll-to-roll coating process on flexible polyethylene terephthalate substrate by a one meter web-width roll-to-roll slot die coating system. We obtained high uniformity PEDOT:PSS coating with optical transmission higher than 80% and sheet resistance lower than 100 Ω/square, and silver containing coating with sheet resistance below 40 Ω/square and maintained optical transmittance. The slot die coating mechanism is investigated and the influencing factors for coating uniformity and defect are defined. The coated transparent conductive film has the same properties as the sputtered ITO and has been used as the TC electrode for printed lighting, whose performance has been proven by standard weathering test for 1000 h. - Highlight: • Controlled synthesis of silver nanowires using trace amount of Cl− ions • Large area roll-to-roll processed transparent conductive (TC) coatings • TC film has light transmission > 80% and sheet resistance < 100 Ω/sq. • Silver containing ink achieved better property than conductive polymer ink. • Used as the TC electrode for printed lighting

  9. NUMERICAL ANALYSIS OF SPLITTING WITHOUT WASTE BASED ON CROSS-WEDGE ROLLING IN DOUBLE ROLLING MECHANISM

    Arkadiusz Tofil

    2013-01-01

    The article presents the results of numerical analysis of splitting without waste on the basis of cross wedge rolling in double rolling mechanism. The analysed process concerns rolling the charge of V-shaped groove, and rotary bending causing the split of the material. In the calculations a method of finite elements (FEM) was used. The obtained results allowed detailed analysis of the splitting process in terms of the level of deformation, strains, material breaking, flow kinematics and stren...

  10. The rolling and skidding of automobile tyres

    Tabor, D.

    1994-09-01

    This article deals in simple terms with the rolling and skidding of automobile tyres. It shows that skid resistance on slippery road surfaces may be significantly increased by using tyre treads of high hysteresis loss.

  11. Moesin regulates neutrophil rolling velocity in vivo.

    Matsumoto, Masanori; Hirata, Takako

    2016-01-01

    During inflammation, the selectin-induced slow rolling of neutrophils on venules cooperates with chemokine signaling to mediate neutrophil recruitment into tissues. Previous studies identified P-selectin glycoprotein ligand-1 (PSGL-1) and CD44 as E-selectin ligands that activate integrins to induce slow rolling. We show here that in TNF-α-treated cremaster muscle venules, slow leukocyte rolling was impaired in mice deficient in moesin, a member of the ezrin-radixin-moesin (ERM) family. Accordingly, neutrophil recruitment in a peritonitis model was decreased in moesin-deficient mice when chemokine signaling was blocked with pertussis toxin. These results suggest that moesin contributes to the slow rolling and subsequent recruitment of neutrophils during inflammation. PMID:27131737

  12. Roll Dynamics in a Free Flying Dragonfly

    Melfi, James; Leonardo, Anthony; Wang, Z. Jane

    2014-11-01

    Dragonflies are capable of executing fast turning maneuvers. A typical free-flight maneuver includes rotations in all three degrees of freedom; yaw, pitch, and roll. This makes it difficult to identify the key changes to wing kinematics responsible for controlling each degree of freedom. Therefore we focus on a single motion; roll about the body longitudinal axis in a combined experimental and computational study. To induce rolling, a dragonfly is released from a magnetic tether while inverted. Both wing and body kinematics are recorded using multiple high speed cameras. The kinematics are replayed in a computer simulation of the flight, with forces and torques based on quasi-steady aerodynamics. By examining the effect of each kinematic change individually, we determine the key changes a dragonfly uses to both instigate, maintain, and end a rolling motion.

  13. Thermal stability of warm-rolled tungsten

    Alfonso Lopez, Angel

    recrystallization occur in tungsten, and quantifying the kinetics and microstructuralaspects of these restoration processes. Two warm-rolled tungsten plates are annealed attemperatures between 1100 °C and 1350 °C, under vacuum conditions or argon atmosphere. Theeffects of annealing on the microstructure are...... recoverykinetics, and recrystallization fitted to JMAK recrystallization kinetics, which in turn allowed thecalculation of recrystallization activation energies. Much faster recovery and recrystallizationkinetics were found for the plate warm-rolled to 90% thickness reduction, as compared to the platewarm......-rolled to 67% thickness reduction. An initial incubation time before recrystallization wasfound for both plates warm-rolled to 67% and 90% thickness reductions. The different Avramiexponents found for the two plates were explained microstructurally in terms of nucleation. The microstructural evolution...

  14. Terras: NATO õppuste roll Euroopas kasvab

    2013-01-01

    Kaitseväe juhataja kindralmajor Riho Terrase sõnul suureneb lähiaastatel NATO õppuste roll Euroopas, sest Afganistanis sõdides saadud kogemust on vaja säilitada ning kasutada seda kollektiivkaitse tugevdamiseks

  15. Cell sorting by deterministic cell rolling

    Choi, Sungyoung; Karp, Jeffrey M.; Karnik, Rohit

    2011-01-01

    This communication presents the concept of “deterministic cell rolling”, which leverages transient cell-surface molecular interactions that mediate cell rolling to sort cells with high purity and efficiency in a single step.

  16. Roll-to-Roll Transfer Printing of Reduced Graphene Oxide Thin Film

    Jang, Hyun-Woo

    2015-01-01

    A novel thin film transfer mechanism has been studied and developed to transfer chemically reduced graphene oxide (r-GO) thin film using a roll-to-roll printing system. We discover that shear stress generated on the silicon rubber stamp surface facilitates delamination of the deposited r-GO thin film efficiently.A roll-to-roll apparatus is assembled to demonstrate the shear-induced transfer printing in a large scale printing system. Shear stress is applied on the stamp surface by rotating the...

  17. Texture comparison between room temperature rolled and cryogenically rolled pure copper

    Nowadays, due to their potential for superior mechanical properties, a considerable interest in bulk ultrafine grained metals exists. One of the possible formation methods for this ultrafine grained material is cryogenic rolling. In this work, the influence of cryogenic rolling on the texture and the microstructure of pure copper is investigated by electron backscatter diffraction (EBSD), both in the deformed and the annealed state. This is done by comparing cryogenically rolled copper with room temperature rolled copper, rolled to the same thickness reductions. A texture difference between the room temperature rolled and cryogenically rolled copper is seen in the deformed state, although the largest texture difference is observed after annealing. These texture differences are mainly attributed to the presence of shear bands in the microstructure of the cryogenically rolled copper. In order to obtain a better understanding of the influence of shear bands on the texture evolution, the grain orientations inside the shear bands are analyzed both experimentally and numerically by applying the visco plastic self-consistent (VPSC) model. A number of shear band specific orientations, which are not observed in the conventional rolling texture of fcc materials, could be identified both in the experimental observations and in the simulations

  18. Effect of asymmetric rolling with cone-shaped rolls on microstructure of low-carbon steel

    A. D. Mekhtiev; Azbanbayev, E. M.; Isagulov, A. Z.; A. R. Karipbayeva; Sv. S. Kvon; Zakariya, N. B.; N. Z. Yermaganbetov

    2015-01-01

    Effect of asymmetric rolling with cone-shaped rolls (ARCSR) on the evolution of microstructure of low-carbon steel was investigated. Steel containing 0,15 % C (wt. %) billet with initial grain size of 60 μm was deformed up to thickness of 5 mm with diameters ratio of 1,5, as well as in cylindrical rolls. Rolling was conducted at three different temperatures: 900 °C, 1 000 °C and 1 100 °C. Final thickness is obtained through four passes of ARCSR with total reduction of 61,7 %. It has been show...

  19. Roll motion analysis of deepwater pipelay crane vessel

    You, Dandan; Sun, Liping; Qu, Zhiguo; Wang, Tao

    2013-12-01

    For a large floating vessel in waves, radiation damping is not an accurate prediction of the degree of roll unlike other degrees of freedom motion. Therefore, to get the knowledge of roll motion performance of deepwater pipelay crane vessels and to keep the vessel working safety, the paper presents the relationship between a series of dimensionless roll damping coefficients and the roll response amplitude operator (RAO). By using two kinds of empirical data, the roll damping is estimated in the calculation flow. After getting the roll damping coefficient from the model test, a prediction of roll motion in regular waves is evaluated. According to the wave condition in the working region, short term statistics of roll motion are presented under different wave parameters. Moreover, the relationship between the maximal roll response level to peak spectral wave period and the roll damping coefficient is investigated. Results may provide some reference to design and improve this kind of vessel.

  20. Financial Controls Project at Rolls Royce

    Samdani, Sandeep

    2006-01-01

    This MBA Project is the result of the Financial Controls Project conducted for UK Gas Turbines Operations at Rolls Royce Plc. The Objectives of this project were to identify the key financial controls which are/ should be operated by the site finance staff in operations at Rolls Royce Global Gas Turbines Operations. Propose Task transfers in Principal from Site finance to other functions, Central teams and Self Directed Teams (SDTs). Identify the challenges, which would arise from reducin...

  1. A longitudinal perspective on rolling forecasts & interactions

    Holmen, Thea Jarneid; Skurtveit, Ingvild

    2015-01-01

    This thesis is a case study exploring the practice of rolling forecasts as a dynamic management tool within an organization. Increasingly complex and dynamic business environment has led to the introduction of contemporary management control systems and management accounting innovations, such as rolling forecasts that is an important tool in the Beyond Budgeting philosophy. Through qualitative research method, this study aims to get an in-depth understanding of how forecasting information, in...

  2. A longitudinal perspective on rolling forecasts & interactions

    Holmen, Thea Jarneid; Skurtveit, Ingvild

    2014-01-01

    Increasingly complex and dynamic business environment has led to the introduction of contemporary management control systems and management accounting innovations, such as rolling forecasts that is an important tool in the Beyond Budgeting philosophy. This thesis is a case study exploring the practice of rolling forecasts as a dynamic management tool within an organization – namely FiGo. Through qualitative research method, the study aims to get an in-depth understanding of how...

  3. Direct hot rolled dual phase weathering steel

    Allam, Tarek

    2016-01-01

    New alloying concepts are proposed to develop hot-rolled weathering-dual phase steels that combine good strength-ductility balance and enhanced atmospheric corrosion resistance. The proposed concepts comprise mainly the alloying elements that improve the atmospheric corrosion resistance (Cu, Ni, P and Cr) and those that facilitate the adjustment of dual phase microstructure during processing by hot rolling (C, Mn and Si). Moreover, Nb and combined Nb-Mo additions are utilized to enable the co...

  4. Characteristics of cold rolled stainless steel sheets

    The cold rolling of sheets of austenitic stainless steel was investigated for different temperatures and percentages of reduction. It was also established under which conditions are the mechanical strenght and the ductility improved. It was found that this improvement is related to the characteristics of martensitic transformation taking place during rolling and through the tensile tests performed in stainless steels with different degree of martensitic transformation. The results are explained on the basis of martensite participation in the stained structure. (Author)

  5. Designing Rolling-Element Bearings

    Moore, James D., Jr.

    2007-01-01

    Bearing Analysis Tool (BAT) is a computer program for designing rolling-element bearings for cryogenic turbomachines. BAT provides a graphical user interface (GUI) that guides the entry of data to develop mathematical models of bearings. The GUI breaks model data into logical subsets that are entered through logic-driven input screens. The software generates a threedimensional graphical model of a bearing as the data are entered. Most dataentry errors become immediately obvious in the graphical model. BAT provides for storage of all the data on a shaft/bearing system, enabling the creation of a library of proven designs. Data from the library can be transferred to subsequent projects by use of simple cut-and-paste routines. BAT includes a library of temperature- dependent cryogenic bearing-material properties for use in the mathematical models. BAT implements algorithms that (1) enable the user to select combinations of design and/or operating-condition parameters, and then (2) automatically optimize the design by performing trade studies over all of the parameter combinations. This feature enables optimization over a large trade space in a fraction of the time taken when using prior bearingmodel software.

  6. Recrystallization of niobium stabilized ferritic stainless steel during hot rolling simulation by torsion tests

    Flávia Vieira Braga

    2016-01-01

    Full Text Available The aim of this study was to investigate the effect of finishing hot rolling temperature in promoting interpass recrystallization on a Nb-stabilized AISI 430 ferritic stainless steel. Torsion tests were performed in order to simulate the Steckel mill rolling process by varying the temperature ranges of the finishing passes. Interrupted torsion test were also performed and interpass recrystallization was evaluated via optical microscopy and electron backscatter diffraction (EBSD. As a result of this work, it has been established, within the restrictions of a Steckel mill rolling schedule, which thermomechanical conditions mostly favor SRX.

  7. 75 FR 42782 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    2010-07-22

    ... COMMISSION Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia AGENCY: United... party group responses to its notice of institution (75 FR 16504, April 1, 2010) were adequate. A record...-year reviews concerning the countervailing duty order on certain hot-rolled flat-rolled...

  8. 49 CFR 393.134 - What are the rules for securing roll-on/roll-off or hook lift containers?

    2010-10-01

    ... or hook lift containers? 393.134 Section 393.134 Transportation Other Regulations Relating to... for securing roll-on/roll-off or hook lift containers? (a) Applicability. The rules in this section apply to the transportation of roll-on/roll-off or hook lift containers. (b) Securement of a...

  9. Energy savings at the hot rolling of semifinished products and shapes

    Flaxa, A.; Spittel, T.

    1987-10-01

    Considering all related restrictions, rolling with reducal initial pass temperature is an effective way to economize on energy in hot rolling semifinished material and sections, without any marked afterinvestments being necessary. In addition to the estimation of the originally applied warming-up technology by means of energy balances and investigations into the heating process, such forming parameters as rolling forces, forming moments and energies as well as rolling material temperatures for an especially selected assortment for medium-and-light-section rolling mill were experimentally and computationally ascertained. The ultimate load of rolls, motors and transfer elements served as the criterion for possible reductions of the initial pass temperature. From this followed proposals to step-by-step reduce the temperature for single sections of the medium and-light-section rolling mill assortment. The economic parameters to be expected were determined and corroborated in the production with 0.12 GJ t/sup -1/ for the intermediate mill and with 0.195 GJ t/sup -1/ for the light section mill. (orig.)

  10. Ultra slow-roll G-inflation

    Hirano, Shin'ichi; Yokoyama, Shuichiro

    2016-01-01

    The conventional slow-roll approximation is broken in the so called "ultra slow-roll" models of inflation, for which the inflaton potential is exactly (or extremely) flat. The interesting nature of (canonical) ultra slow-roll inflation is that the curvature perturbation grows on superhorizon scales, but has a scale-invariant power spectrum. We study the ultra slow-roll inflationary dynamics in the presence of non-canonical kinetic terms of the scalar field, namely ultra slow-roll G-inflation. We compute the evolution of the curvature perturbation and show that the primordial power spectrum follows a broken power law with an oscillation feature. It is demonstrated that this could explain the lack of large-scale power in the cosmic microwave background temperature anisotropies. We also point out that the violation of the null energy condition is prohibited in ultra slow-roll G-inflation and hence a blue tensor tilt is impossible as long as inflation is driven by the potential. This statement is, however, not tr...

  11. Partition Decomposition for Roll Call Data

    Leibon, Greg; Rockmore, Daniel N; Savell, Robert

    2011-01-01

    In this paper we bring to bear some new tools from statistical learning on the analysis of roll call data. We present a new data-driven model for roll call voting that is geometric in nature. We construct the model by adapting the "Partition Decoupling Method," an unsupervised learning technique originally developed for the analysis of families of time series, to produce a multiscale geometric description of a weighted network associated to a set of roll call votes. Central to this approach is the quantitative notion of a "motivation," a cluster-based and learned basis element that serves as a building block in the representation of roll call data. Motivations enable the formulation of a quantitative description of ideology and their data-dependent nature makes possible a quantitative analysis of the evolution of ideological factors. This approach is generally applicable to roll call data and we apply it in particular to the historical roll call voting of the U.S. House and Senate. This methodology provides a...

  12. Roll bonding of 6061 aluminum alloy plates

    The roll bonding process is an important application of the solid state welding . in principle, two or more slabs of the materials to be bonded are placed in contact and welded around the edges. then, this assembled set is heated and rolled until the required thickness is obtained. this process is applied to clad the nuclear fuel, with high strength aluminum alloys during fabrication of plate type nuclear fuel elements for research reactors, or to produce many new constructions which have special uses in industrial applications. in the present work, the steps of the hot roll bonding of 6061 aluminum alloy plates were studies by using both microscopic examination and mechanical test namely singe lap shear strength test. also the effect of reduction degree in thickness, the sequence of hot rolling , surface roughness, degassing opening length and holding time on roll bonding process were studied. the results obtained due to variations in the above parameters are discussed with respect to their effects on the roll bonding of 6061 aluminum alloy plates as well as their effects on the specifications of the fuel plates

  13. Rolling in Nature and Robotics: A Review

    Rhodri H. Armour; Julian F. V. Vincent

    2006-01-01

    This paper presents a review of recent rolling robots including Rollo from Helsinki University of Technology,Spherical Mobile Robot from the Politecnico of Bari,Sphericle from the University of Pisa,Spherobot from Michigan State University,August from Azad University of Qazvin and the University of Tehran,Deformable Robot from Ritsumeijan University,Kickbot from the Massachusetts Institute of Technology,Gravitational Wheeled Robot from Kinki University,Gyrover from Carnegie Seven rolling robot design principles are presented and discussed (Sprung central member,Car driven,Mobile masses,Hemispherical wheels,Gyroscopic stabilisation,Ballast mass - fixed axis,and Ballast mass - moving axis). Robots based on each of the design principles are shown and the performances of the robots are tabulated. An attempt is made to grade the design principles based on their suitability for movement over an unknown and varied but relatively smooth terrain. The result of this comparison suggests that a rolling robot based on a mobile masses principle would be best suited to this specific application.Some wonderful rolling organisms are introduced and defined as "active" or "passive" depending on whether they generate their own rolling motion or external forces cause their rolling.

  14. Wear phenomena of spinning rolls for stone wool production

    Klimpel, A; L.A. Dobrzański; A. Lisiecki; D. Janicki

    2006-01-01

    Purpose: Purpose of this paper: Results of the study of wear phenomena of cascade spinning rolls during stone wool production process are described.Design/methodology/approach: The study were based on direct process observations, chemical analysis and temperature measurements of basalt lava, metallographic examinations of the spinning rolls deposits.Findings: It was showed that the deposits of spinning rolls are worn in very different way, depending on the roll position in rolls cascade. Pred...

  15. Numerical simulation of wear of basalt lava spinning rolls

    A. Lisiecki; A. Klimpel; D. Janicki

    2006-01-01

    Purpose: of this paper: Results of the study of wear phenomena of cascade spinning rolls during stone woolproduction process are described.Design/methodology/approach: The study was based on direct process observations, chemical analysis andtemperature measurements of basalt lava, metallographic examinations of the spinning rolls deposits. It was showedthat the deposits of spinning rolls are worn in very different way, depending on the roll position in rolls cascade.Findings: Predominant wear...

  16. Calculation and Analysis of Temperature Distribution in Hot Rolling Strip

    Kaixiang Peng

    2013-01-01

    Modern steel grades require constant and reproducible production conditions both in the hot strip mill and in the cooling section to achieve constant material properties along the entire strip length and from strip to strip. Calculation of the temperature in final rolling process always utilizes factors such as the work piece's inner organizational structure, plastic deformation, and it's variations of properties and so on, also as well as the physical parameters such as gauge, shape, etc. In...

  17. Microstructure and properties of hot roll bonding layer of dissimilar metals. 2. Bonding interface microstructure of Zr/stainless steel by hot roll bonding and its controlling

    The hot roll bonding of zirconium and stainless steel inserted with tantalium was investigated using the newly developed rolling mill. The effect of hot rolling temperatures of zirconium/stainless steel joints on bonding interface structure was evaluated. Intermetallic compound layer containing cracks was observed at the bonding interface between stainless steel and tantalium when the rolling temperature was above 1373K. The hardness of the bonding layer of zirconium and tantalium bonded above 1273K was higher than tantalium or zirconium base metal in spite of absence of intermetallic compound. The growth of reaction layer at the stainless steel and tantalium interface and at the tantalium and zirconium interface was conforming a parabolic low when that was isothermally heated after hot roll bonding, and the growth rate was almost same as that of static diffusion bonding without using hot roll bonding process. It is estimated that the strain caused by hot roll bonding gives no effect on the growth of reaction layer. It was confirmed that the dissimilar joint of zirconium and stainless steel with insert of tantalium having the sound bonding interface were obtained at the suitable bonding temperature of 1173K by the usage of the newly developed hot roll bonding process. (author)

  18. Long-and Short-Term Self-Learning Models of Rolling Force in Rolling Process Without Gaugemeter of Plate

    ZHU Fu-wen; ZENG Qing-liang; HU Xian-lei; LI Xi-an; LIU Xiang-hua

    2009-01-01

    .Owing to a lack of gaugemeter and the variety of steel grades and standards in some plate mills,the longand short-term self-learning models of rolling force based on gauge soft-measuring with high precision were brought up.The soft-measuring method and target value locked method were used in these models to confirm the actual exit gauge of passes,and thick layer division and exponential smoothing method were used to dispose the deformation resistance parameter,which could be calculated from the actual data of the rolling process.The correlative mathematical methods can also be adapted to self-learning with gaugemeter.The models were applied to the process control system of AGC (automatic gauge control) reconstruction on 2 800 mm finishing mill of Anyang steel and favorable effect was obtained.

  19. Roll-to-roll paper sensors (ROPAS); Wireless communicating sensors on paper in the logistic chain

    Rentrop, C.; Rubingh, J.E.J.M.; Lelieveld, R.; Sandberg, H.

    2014-01-01

    The ROPAS project (Roll-to-roll paper sensors) combines high end electronics and wireless sensors with low cost paper substrates and processing techniques that can be applied on a large scale. Paper is the next step in the printed electronics roadmap of utilising cheaper substrate materials as a rep

  20. Roll-to-roll fabricated lab-on-a-chip devices

    Vig, Asger Laurberg; Mäkelä, Tapio; Majander, Päivi;

    2011-01-01

    We present a high-volume fabrication technique for making polymer lab-on-a-chip devices. Microfluidic separation devices, relying on pinched flow fraction, are roll-to-roll fabricated in a cellulose acetate (CA) film at a volume of 360 devices h−1 for a cost of approximately 0.5 euro/device. The ...

  1. Optimization of cold rolling process parameters in order to increasing rolling speed limited by chatter vibrations

    Ali Heidari

    2013-01-01

    Full Text Available Chatter has been recognized as major restriction for the increase in productivity of cold rolling processes, limiting the rolling speed for thin steel strips. It is shown that chatter has close relation with rolling conditions. So the main aim of this paper is to attain the optimum set points of rolling to achieve maximum rolling speed, preventing chatter to occur. Two combination methods were used for optimization. First method is done in four steps: providing a simulation program for chatter analysis, preparing data from simulation program based on central composite design of experiment, developing a statistical model to relate system tendency to chatter and rolling parameters by response surface methodology, and finally optimizing the process by genetic algorithm. Second method has analogous stages. But central composite design of experiment is replaced by Taguchi method and response surface methodology is replaced by neural network method. Also a study on the influence of the rolling parameters on system stability has been carried out. By using these combination methods, new set points were determined and significant improvement achieved in rolling speed.

  2. Technology development for roll-to-roll production of organic photovoltaics

    Galagan, Y.O.; Vries, I.G. de; Langen, A.P.; Andriessen, H.A.J.M.; Verhees, W.J.H.; Veenstra, S.C.; Kroon, J.M.

    2011-01-01

    In order to reach the objective of low-cost, large area organic photovoltaic systems, we build up a knowledge base concerning the influence of process conditions on the performance of polymer solar cells. A large area solar cell module, with roll-to-roll coated PEDOT:PSS and photoactive layers (base

  3. Roll-to-roll processed polymer tandem solar cells partially processed from water

    Larsen-Olsen, Thue Trofod; Andersen, Thomas Rieks; Andreasen, Birgitta;

    2012-01-01

    Large area polymer tandem solar cells completely processed using roll-to-roll (R2R) coating and printing techniques are demonstrated. A stable tandem structure was achieved by the use of orthogonal ink solvents for the coating of all layers, including both active layers. Processing solvents...... with upscaling the multilayer tandem cells were identified giving valuable information for future experiments and development....

  4. Surface finishing and levelling of thermomechanically hardened rolled steel

    The finishing of high-strength merchant shapes from alloy steel was tried out under industrial conditions with the equipment of metallurgical plants. After thermomechanical hardening in the production line of the rolling mill, 30KhGSN2A and 40Kh1NVA steel rounds 32 and 31 mm in diameter were straightened on a two-roller straightening machine designed by the All-Union Scientific Research Institute for Metallurgical Machinery (VNII Metmash). This made possible subsequent turning and grinding of the rods. The conditions of straightening, turning and grinding have been worked so as to obtain thermomechanically strengthened and ground rolled products approximating the gauged and ground metal in shape geometry and surface finish. It is shown that the labour-consuming operation of turning can be eliminated by reducing the machining pass of the rolled product, and this lowers the labour required for the finishing operations by 75%. After grinding with 40- and 25-grain abrasive wheels, high strength rolled shapes were obtained with a diameter of 30-0.20 mm and a surface finish of class 6-5 satisfying the technical specifications. (author)

  5. Microstructural heterogeneity of forged rolled rings

    J. Herian

    2007-04-01

    Full Text Available Purpose: The paper presents the processes which condition the quality of steel cast strands and properties of rolled products. It touches upon the technology of small-size rings manufacture from the 42CrMo4 steel used for the production of rolling bearings and toothed rings.Design/methodology/approach: Investigations were made on the 42CrMo4 steel based process of small-size rings manufacture of weight not exceeding 100 kg and the internal diameter up to 600 mm.Findings: Microstructure heterogeneity has been proven on the cross section of rods and rings under hot rolling and thermal treatment. Non-uniformity in hardness distribution was found on the hot rolled rings’ face surface and cross section. Final products made from rings with heterogeneous properties characterize: difficulties with machining, cracking during surface hardening and decrease of life time. After the process modification, the rings’ microstructure homogeneity and advantageous hardness distribution were obtained.Practical implications: A good quality of final rings after heat treatment is obtained in the case of charge characterized by a uniform pearlitic/ferritic microstructure. After the process technology modification, the rings’ microstructure homogeneity and advantageous hardness distribution were obtained.Originality/value: The minimum processing degree in the rolling of rod products should guarantee obtaining a homogeneous microstructure on the rings cross section and properties which would ensure a good quality and the required functional properties of the final products.

  6. Controlled rolling and accelerated cooling of steel

    Ranta, H.; Korhonen, A.S.; Partinen, S.

    1993-12-31

    The subproject `Controlled Rolling and Cooling of Steel` was carried out at the Helsinki University of Technology in the Laboratory of Processing and Heat Treatment of Materials during the years 1989-91. The work described here was a part of a SULA-project. The aim of the project at the Helsinki University of Technology was to study controlled rolling and accelerated cooling and the temperature and strain distributions in the steel during rolling. Modelling of accelerated cooling is important in ensuring that the desired shape and mechanical properties of steel are obtained without additional heat treatment. When no additional heat treatments are needed after the rolling process, it is possible to increase the volume of production and to save time and money. Mathematical models were studied and developed to describe the processes and to make it possible to predict the shape and mechanical properties of the final product. Models are also needed to study the influence of various processing parameters. Since full-scale experiments are expensive, a laboratory-scale cooling line for hot rolling experiments was constructed. During this project numerous hot forming and accelerated cooling experiments were carried out

  7. Magnon Inflation: Slow Roll with Steep Potentials

    Adshead, Peter; Burgess, C P; Hayman, Peter; Patil, Subodh P

    2016-01-01

    We find multi-scalar effective field theories (EFTs) that can achieve a slow inflationary roll despite having a scalar potential that does not satisfy the usual slow-roll condition (d V)^2 << V^2/Mp^2. They evade the usual slow-roll conditions on $V$ because their kinetic energies are dominated by single-derivative terms rather than the usual two-derivative terms. Single derivatives dominate during slow roll and so do not require a breakdown of the usual derivative expansion that underpins calculational control in much of cosmology. The presence of such terms requires some sort of UV Lorentz-symmetry breaking during inflation (besides the usual cosmological breaking). Chromo-natural inflation provides an example of a UV theory that can generate the multi-field single-derivative terms we consider, and we argue that the EFT we find indeed captures the slow-roll conditions for the background evolution for Chromo-natural inflation. We also show that our EFT can be understood as a multi-field generalization ...

  8. Applying contextual interference to the Pawlata roll.

    Smith, P J; Davies, M

    1995-12-01

    Contextual interference is manipulated by changing the practice order of a number of similar motor tasks, so that the learning context of each interferes with that of the other. The effect has been found to generalize to baseball batting, badminton serving and volleyball skills. The present study examined whether this practice technique could be applied to a Pawlata roll in a kayak. The study was further motivated by the fact that many instructors in Britain currently advocate learning the Pawlata roll in one direction only to a criterion of accuracy, thereafter transferring to the opposite direction. Contextual interference literature predicts that skill retention would be better served by practising on alternate sides. Accordingly, 16 undergraduate students with no kayaking experience were randomly allocated to either a low contextual interference group, which followed U'ren's (1993) recommendations, or a high contextual interference group, which practised the skill on alternate sides. The high contextual interference group took less time to acquire the skill, and were also quicker to achieve successful performance in retention (full roll) and transfer (half roll) tests, regardless of the direction of the roll, 1 week later. The time savings in practice were not expected, as acquisition under high contextual interference was improved rather than impaired. This finding suggests that bilateral transfer was increased by randomizing practice. These results are worthy of further investigation, in that they suggest that the recommended training methods may not be optimal. PMID:8850571

  9. Development of multivariable control for bar and wire rod rolling and control system for close-tolerance bar rolling. Boko/senzai atsuen no tahensu seigyo to seimitsu atsuen system no kaihatsu

    Noguchi, Y.; Okamura, K.; Ogai, H.; Baba, K.; Naganuma, Y.; Ishii, H. (Nippon Steel Corp., Tokyo (Japan))

    1992-11-30

    Regarding an application of the modern control theory to the continuous rolling, the multivariable control simulations of the cold rolling mill have been reported so far. Since the requirements for a higher dimensional accuracy of the bar and wire rod products also have been raised by the users today, for corresponding to it, the development of sophisticated dimension control technology for the continuous rolling has been desired. In order to realize the rolling with a higher accuracy, by the authors, using the rolling state equations and the optimal regulator theory, the state equations required for designing the control system for the bar mill, intermediate wire rod mill and wire rod finishing block mill have been established and a multivariable control system has been developed. In addition, at the bar mill in the Muroran steelwork of the Nippon Steel Corp., a precision bar rolling system consisted of the inter-billet dimension control and the in-billet dimension control by this control method has been put into practice. By using it, a stable precision rolling has been realized, and moreover, the automation of rolling and the skillfree operation have been achieved. 19 refs., 13 figs., 2 tabs.

  10. Influence of sway motion on passive anti-rolling tank

    2006-01-01

    The passive anti-rolling tank is one of important ship stabilizers widely used today. But at present, research of the tank is most aimed at its rolling movement. In this paper, the influence of sway motion on the passive anti-rolling tank is considered, the mathematical model of "ship-passive anti-rolling tank" system coupled with sway motion is developed basing on the U-shaped passive anti-rolling tank theory. Both simulation results and experimental data indicate that it is necessary to consider the influence of sway motion on the anti-rolling tank, which is more agreeable to the actual circumstance.

  11. Decision Support for the Rolling Stock Dispatcher

    Groth, Julie Jespersen

    Real-time recovery is receiving a fast growing interest in an increasingly competitive railway operation market. This thesis considers the area of rolling stock dispatching which is one of the typical real-time railway dispatching problems. All work of the thesis is based on the network and...... problems of passenger railway transportation and the decomposed solution process of the rolling stock recovery problem. The paper on the robustness analysis has been accepted for submission in the International Journal of Operations Research. Two of the papers have been submitted to journals and are being...... planning processes of the railway operator DSB S-tog a/s. In the thesis the problems existing in the railway planning process from the strategic to real-time level are briefly sketched. Network planning, line planning, timetabling, crew and rolling stock planning is outlined and relevant references are...

  12. Can Quintessence Be the Rolling Tachyon?

    李新洲; 郝建纲; 刘道军

    2002-01-01

    In the light of the recent works by Sen (hep-th/0203211, hep-th/0203265, hep-th/0204143) and Gibbons (helth/0204008), we present a phase-plane analysis on the cosmology containing a rolling tachyon field in a potential resulting from string theory. We show that there is no stable point on the phase-plane, which indicates that there is a coincidence problem if we consider the tachyon as a candidate for quintessence. Furthermore, we also analyse the phase-plane of the cosmology containing a rolling tachyon field for an exactly solvable toy potential in which the critical point is stable. Therefore, it is possible for the rolling tachyon to be a candidate for quintessence if we give up the strict constraint on the potential or find a more appropriate effective potential for the tachyon from M/string theory.

  13. Texture of rolling and recrystallization of terbium

    X-Ray pole figure method was used for investigation into cold rolling texture and recrystallization on samples of pure and commercial terbium. It was revealed that slip over (0001)[1120] system was the main deformation mechanism in terbium. Recrystallization annealing at 600 deg C for 30 min did not change the character of texture with (0001)[0101] basic component. Presence of basic texture as in cold rolled so in annealed samples resulted in isotropy of physical and mechanical properties in the plane of rolling and in their sharp variation in the perpendicular direction. Impurities were found to make basic slip diffucult and to reduce by half the intensity of basic texture component, not affecting the others

  14. Computer-aided roll pass design in rolling of airfoil shapes

    Akgerman, N.; Lahoti, G. D.; Altan, T.

    1980-01-01

    This paper describes two computer-aided design (CAD) programs developed for modeling the shape rolling process for airfoil sections. The first program, SHPROL, uses a modular upper-bound method of analysis and predicts the lateral spread, elongation, and roll torque. The second program, ROLPAS, predicts the stresses, roll separating force, the roll torque and the details of metal flow by simulating the rolling process, using the slab method of analysis. ROLPAS is an interactive program; it offers graphic display capabilities and allows the user to interact with the computer via a keyboard, CRT, and a light pen. The accuracy of the computerized models was evaluated by (a) rolling a selected airfoil shape at room temperature from 1018 steel and isothermally at high temperature from Ti-6Al-4V, and (b) comparing the experimental results with computer predictions. The comparisons indicated that the CAD systems, described here, are useful for practical engineering purposes and can be utilized in roll pass design and analysis for airfoil and similar shapes.

  15. A Granular Model of Rolling Grain Ripples

    Andersen, K H

    1999-01-01

    A simple model is presented for the formation of rolling grain ripples on a flat sand bed by the oscillatory flow from a surface wave. The model is related to physical parameters of the problem, and is solved for the equilibrium spacing and height of the ripples. Good agreement between the model and measurements of rolling grain ripples is demonstrated. It is found that the length of the ripples scale with the square-root of the non-dimensional shear stress on a flat bed.

  16. Contact conditions in skin-pass rolling

    Kijima, Hideo; Bay, Niels

    2007-01-01

    The special contact conditions in skin-pass rolling of steel strip is analysed by studying plane strain upsetting of thin sheet with low reduction applying long narrow tools and dry friction conditions. An extended sticking region is estimated by an elasto-plastic FEM analysis of the plane strain...... upsetting. This sticking region causes a highly inhomogeneous elasto-plastic deformation with large influence of work-hardening and friction. A numerical analysis of skin-pass rolling shows the same contact conditions, i.e. an extended sticking region around the center of the contact zone. The calculated...

  17. Hot rolling of intermetallics FeAl phase based alloys

    G. Niewielski

    2008-02-01

    Full Text Available Purpose: The one of major problem restricting universal employment of intermetallic phase base alloy istheir low plasticity which leads to hampering their development as construction materials. The following workconcentrates on possibilities to form through rolling process the alloys with various aluminium content.Design/methodology/approach: After casting and annealing, alloy specimens were subjected to axialsymmetriccompression at temperatures ranging from 900 to 1200°C at 10 s-1 strain rates. In order to analyse theprocesses which take place during deformation, the specimens after deformation were intensely cooled with water.Structural examination was carried out using light microscopy. The process was conducted on the K -350 quartorolling mill used for hot rolling of flat products. The process was conducted in some stages in at temperaturesranging from 1200-900°C:Findings: The research carried out enabled the understanding of the phenomena taking place during hot rolling ofthe investigated alloy. An alloy with 38%at. aluminium concentration can be plastically formed at a temperature of upto 900°C, which has been also confirmed in plastometric studies conducted in the form of hot compression tests.Research limitations/implications:Practical implications: The obtained sheets can be used as constructional elements working in complex stressfields, at a high temperature and corrosive environmentsOriginality/value: The tests have shown that it is possible to form the investigated alloys through rolling processingonly where shields are applied. Rolling of the alloys without shields led to the occurrence of a grid of cracks.

  18. COMPARISON BETWEEN MODELS FOR CALCULATION OF INDUSTRIAL HOT ROLLING LOADS

    Antonio Augusto Gorni

    2012-09-01

    Full Text Available An evaluation is made about the precision of hot strip rolling mill loads at the F1 stand calculated according to the theoretical models of Orowan, Sims, Alexander-Ford, Orowan-Pascoe, Ekelund and Tselikov in comparison to real values got for carbon-manganese steels. In the deterministic approach, without any fit of the calculated values to real data, Orowan, Sims and Alexander-Models show best levels of precision, as expected from the information got in the literature. However, in the semi-empirical approach, after a linear fit between calculated values and real data, Tselikov and Ekelund models show better adequacy to the industrial data, a fact that can be attributed to more significant errors occurring in the sub-models of temperature, tribology and hot strength than in the rolling load models. For its turn, neural network models show the best levels of precision which make very attractive the adoption of this approach.

  19. THE DEVELOPMENT OF TECHNOLOGY OF THE CORE THERMO-MECHANICALLY HARDENED REINFORC-ING STEEL OF GRADE A700HW OF DIE-ROLLED SECTION NO 12, 14, 16 PRODUCTION ACCORDING TO REQUIREMENT OF FINNISH STANDARDS SFST1216 IN CONDITIONS OF SMALL-SECTION MILL 320 OF RUP «BMZ»

    A. V. Rusalenko

    2009-01-01

    Full Text Available The development of technology of the core thermomechanically hardened reinforcing steel of grade А700HW of die-rolled section No 12, 14, 16 production according to requirement of Finnish standards SFST1216 in conditions of small-section mill 320 of RUP «BMZ» is given.

  20. RATIONING OF ELECTRICITY PRODUCTION IN THE ROLLING OF FERROUS METALLURGY

    Hoshimov, Fozildzhon; Rakhmonov, Ikromdzhon

    2014-01-01

    In given to article rationing of the electric power in rolling production of ferrous metallurgy is considered questions and the analysis of resultant sizes of a specific expense of the electric power for a variety and ball rolling.

  1. NON-CENTRAL ROLLING OF FLAT WORKS WITH TAPERED THICKNESS

    I. A. Isaevich

    2016-02-01

    Full Text Available The way of forming of variable shape strips with rolling in non-drive waves with rounding by the movable arbor strip is analyzed. The way of rolling with derivation of speeds of deforming instruments is offered.

  2. Deformation and recrystallization textures in straight-rolled and pseudo cross-rolled AA 3105 aluminum alloy

    The hot band of CC AA 3105 aluminum alloy was cold-rolled to different reductions along the original rolling and transverse directions, and then annealed at 427 oC for 24 h. The deformation and recrystallization textures in these cold-rolled sheets were investigated by X-ray diffraction. The result shows that further rolling of the hot band along the original rolling direction incrementally strengthens the β fiber rolling texture. Under cross-rolling (i.e., along the original transverse direction), the former β fiber orientations are unstable and they gradually rotate towards the β fiber in the new sample reference system. The recrystallization is completed at a lower reduction in the cross-rolled specimens than in the straight-rolled specimens. The recrystallization texture of the straight-rolled specimens is characterized by the major P component and the minor R and Goss components. The recrystallization texture of the cross-rolled specimens depends on the cross-rolling reduction. As the cross-rolling reduction increases from 33% to 90%, the recrystallization texture is changed from the {0 1 2} texture through {1 11 7} to the P texture.

  3. Cross-directional interlocking of rolls in an air press of a papermaking machine

    Beck, David A.; Gorshe, Thomas

    2003-05-13

    An air press for pressing a paper web is composed of a plurality of rolls including at least a first roll and a second roll. The first roll and the second roll are positioned adjacent one another and form a first nip therebetween. Further, the first roll and the second roll each have a roll end, the roll end of the first roll adjoining the roll end of the second roll. A bevel plate is attached to the roll end of the first roll, the bevel plate having at least a first angled plate face. A seal ring is positioned adjacent the roll end of the second roll, the seal ring being juxtaposed to the bevel plate. The seal ring has at least a first angled ring face, and the first angled ring face mates with the first angled plate face.

  4. 40 CFR 467.20 - Applicability; description of the rolling with emulsions subcategory.

    2010-07-01

    ... rolling with emulsions subcategory. 467.20 Section 467.20 Protection of Environment ENVIRONMENTAL... Rolling With Emulsions Subcategory § 467.20 Applicability; description of the rolling with emulsions... the rolling with emulsions subcategory....

  5. 40 CFR 467.10 - Applicability; description of the rolling with neat oils subcategory.

    2010-07-01

    ... rolling with neat oils subcategory. 467.10 Section 467.10 Protection of Environment ENVIRONMENTAL... Rolling With Neat Oils Subcategory § 467.10 Applicability; description of the rolling with neat oils... the rolling with neat oils subcategory....

  6. Multi-scale roughness transfer in cold metal rolling

    Plouraboué, Franck; Boehm, Matthieu

    1999-01-01

    We report on a comparative Atomic Force Microscope (AFM) multi-scale roughness analysis of cold rolled Al alloy and steel roll, in order to characterize the roughness transfer from the steel roll to the workpiece in cold strip rolling processes. More than three orders of length-scale magnitudes were investigated from 100 microns to 50 nanometers on both types of surfaces. The analysis reveals that both types of surfaces are anisotropic self-affine surfaces. Transverse and longitudinal height p...

  7. Continuous extrusion and rolling forming technology of copper strip manufacture

    Yun Xinbing; Zhou Mo; Tian Tian; Zhao Ying

    2015-01-01

    Continuous extrusion and rolling technology was proposed as a new strip production technology. It finished hot rolling process using the waste heat of the continuous extrusion forming. The continuous extrusion and rolling forming process was simulated by DEFORM-3DT software. The influence of extrusion wheel velocity and strip size on the continuous extrusion and rolling forming process was analyzed. The experiment was carried out according to optimized results of numerical simulation, the mic...

  8. The role of internal communication in the rolling forecast process

    Sorvari, Jiri

    2010-01-01

    Objective of the Study The objective of the study was to examine the role of internal communication in the rolling forecast process. The study analysed the role of internal communication through four research questions: 1) What communication practices are connected with the rolling forecast process? 2) Which organisational attributes influence the internal communication climate in the rolling forecast process? 3) How is management and strategic communication incorporated in the rolling fo...

  9. Impact of commodity index rolls on the futures term structure

    Roslander, Risto-Matti

    2013-01-01

    OBJECTIVES OF THE STUDY: In this thesis, I study the effects of commodity index rolls on nearby commodity futures returns and futures term structure. More specifically, I examine the impact of commodity index investors' and speculators' positions on roll yields of nearby futures contracts during the "Goldman roll". In addition, I study the futures returns in the post-rolling period. Furthermore, by employing daily dollar volumes, my objective is to calculate the effect of liquidity in the...

  10. Discussion on mandrel retained speed and circulation process of Assel 3-roll pipe mill%Assel三辊轧管机组芯棒限动速度及循环工艺的探讨

    原亚琴

    2009-01-01

    This paper mainly focuses on the selection of the retained speed and the circulation process of the mandrel in Assel 3-roll pipe mill. The importance of mandrel cooling and lubrication during circulation has been summarized through analysis of the relation between the retained speed and the pre-threading travel, man-drel size and shell length and thickness.%对Assel三辊轧管机组中芯棒的限动速度的选定原则和芯棒循环工艺流程进行了探讨.分析了限动速度与预插入行程、芯棒规格和荒管长度、壁厚的关系,叙述了芯棒循环中冷却与润滑的方法.

  11. Optimization of Preventive Grinding of Backup Roll against Contact Fatigue Cracking

    DOU Peng; LI You-guo; LIANG Kai-ming; BAI Bing-zhe

    2005-01-01

    In order to optimize the current grinding procedure of the backup roll of 2050 continuously variable crown (CVC) mills, the behavior of rolling contact fatigue (RCF) cracking was investigated. Two RCF short cracks, including vertical short crack and ratcheting short crack initiated from ratcheting, were observed. The behavior of both RCF cracks was analyzed in detail. Then a modified grinding procedure was proposed according to the behavior of RCF cracks and the preventive grinding strategy.

  12. Recrystallization of niobium stabilized ferritic stainless steel during hot rolling simulation by torsion tests

    Flávia Vieira Braga; Diana Pérez Escobar; Thompson Junior Ávila Reis; Nilton José Lucinda de Oliveira; Margareth Spangler Andrade

    2016-01-01

    The aim of this study was to investigate the effect of finishing hot rolling temperature in promoting interpass recrystallization on a Nb-stabilized AISI 430 ferritic stainless steel. Torsion tests were performed in order to simulate the Steckel mill rolling process by varying the temperature ranges of the finishing passes. Interrupted torsion test were also performed and interpass recrystallization was evaluated via optical microscopy and electron backscatter diffraction (EBSD). As a result ...

  13. Investigation of surface layer on rolled recycled AA5050 in relation to Filiform Corrosion

    Premendra

    2007-01-01

    The presence of a heavily deformed surface layer (a few microns thick) on rolled aluminium alloy is understood to be one of the main reasons contributing to the Filiform Corrosion (FFC) susceptibility of the alloy. The surface layer is formed during the thermo-mechanical processing of the sheet metal, in the rolling mills. The surface layer characteristics are process dependent, i.e. depends on thermo-mechanical processing and the composition of the alloy in addition to post-production surfac...

  14. Oscillations and Rolling for Duffing's Equation

    Aref'eva, I. Ya.; Piskovskiy, E. V.; Volovich, I. V.

    2013-01-01

    The Duffing equation has been used to model nonlinear dynamics not only in mechanics and electronics but also in biology and in neurology for the brain process modeling. Van der Pol's method is often used in nonlinear dynamics to improve perturbation theory results when describing small oscillations. However, in some other problems of nonlinear dynamics particularly in case of Duffing-Higgs equation in field theory, for the Einsten-Friedmann equations in cosmology and for relaxation processes in neurology not only small oscillations regime is of interest but also the regime of slow rolling. In the present work a method for approximate solution to nonlinear dynamics equations in the rolling regime is developed. It is shown that in order to improve perturbation theory in the rolling regime it turns out to be effective to use an expansion in hyperbolic functions instead of trigonometric functions as it is done in van der Pol's method in case of small oscillations. In particular the Duffing equation in the rolling regime is investigated using solution expressed in terms of elliptic functions. Accuracy of obtained approximation is estimated. The Duffing equation with dissipation is also considered.

  15. Large Scale Evaluation fo Nickel Aluminide Rolls

    None

    2005-09-01

    This completed project was a joint effort between Oak Ridge National Laboratory and Bethlehem Steel (now Mittal Steel) to demonstrate the effectiveness of using nickel aluminide intermetallic alloy rolls as part of an updated, energy-efficient, commercial annealing furnace system.

  16. Nigeria - Lagos Rolling First Public Expenditure Review

    World Bank

    2010-01-01

    This review provides an analysis of the fiscal performance and sustainability of the State of Lagos, performance of the budgeting system and of the public procurement system. It is the first in a planned rolling Public Expenditure Reviews (PERs) for Lagos state. The analysis finds that the state's fiscal policy is broadly sound and that its fiscal program is sustainable in the medium term,...

  17. Hot rolling of gamma titanium aluminide foil

    Metal flow and microstructure evolution during the thermomechanical processing of thin-gage foil of a near-gamma titanium aluminide alloy, Ti-45.5Al-2Cr-2Nb, with an equiaxed-gamma microstructure was investigated experimentally and theoretically. Foils of thickness of 200-250 μm were fabricated via hot rolling of sheet in a can of proprietary design. The variation in gage of the rolled foils was ±15 μm except in very sporadic (local) areas, with variations of approximately 60 μm relative to the mean. Metallography revealed that the larger thickness variations were associated with large remnant colonies lying in a hard orientation for deformation. To rationalize these observations, a self-consistent model was used to estimate the strain partitioning between the softer (equiaxed-gamma) matrix and the remnant colonies. Furthermore, the efficacy of pre- or post-rolling heat treatment in eliminating remnant colonies was demonstrated and quantified using a static-spheroidization model. The elimination of remnant colonies via spheroidization prior to foil rolling gave rise to improved gage control.

  18. The riddles of rock and roll

    L.J.M. d' Anjou (Leo)

    2003-01-01

    textabstractRock and roll has often been equated with rebellion. The genre, though, is just a form of popular music and many of the important players in the game of promoting it were, like the saying goes, only in it for the money. As a rule, music like that will be supportive of the social order ra

  19. Detection of Parametric Roll on Ships

    Galeazzi, Roberto; Blanke, Mogens; Poulsen, Niels Kjølstad

    2012-01-01

    Recent years have shown several incidents with dramatic damage on container vessels caused by parametric resonance. When the resonance starts, the roll oscillation at a sub-harmonic frequency of the wave excitation may be completely unexpected. Timely warning about the onset of the resonance phen...... experimental data from towing tank tests and data from a container ship passing an Atlantic storm....

  20. Rolling Friction on a Wheeled Laboratory Cart

    Mungan, Carl E.

    2012-01-01

    A simple model is developed that predicts the coefficient of rolling friction for an undriven laboratory cart on a track that is approximately independent of the mass loaded onto the cart and of the angle of inclination of the track. The model includes both deformation of the wheels/track and frictional torque at the axles/bearings. The concept of…

  1. Youth, Rock 'n' Roll, and Electronic Media.

    Snow, Robert P.

    1987-01-01

    Rock 'n' Roll as a form of electronic communication is central to youth culture. There are procedural rules similar to grammatical structures which allow meaningful interpretation of this musical experience. As new forms of communication appear both youth culture and the meaning of music are altered to encompass the changes. (VM)

  2. Development of a Rolling Process Design Tool for Use in Improving Hot Roll Slab Recovery

    Lawrence Livermore National Laboratory participated in a U. S. Department of Energy/Office of Industrial Technology sponsored research project 'Development of a Rolling Process Design Tool for Use in Improving Hot Roll Slab Recovery', as a Cooperative Agreement TC-02028 with the Alcoa Technical Center (ATC). The objective of the joint project with Alcoa is to develop a numerical modeling capability to optimize the hot rolling process used to produce aluminum plate. Product lost in the rolling process and subsequent recycling, wastes resources consumed in the energy-intensive steps of remelting and reprocessing the ingot. The modeling capability developed by project partners will be used to produce plate more efficiently and with reduced product loss

  3. Sub-optimality analysis of mobile robot rolling path planning

    张纯刚; 席裕庚

    2003-01-01

    Rolling planning is an efficient method for path planning in uncertain environment. In this paper, the general principle and algorithm of mobile robot path planning based on rolling windows are studied. The sub-optimality of rolling path planning is analyzed in details and explained with a concrete example.

  4. NORMAL PRESSURE AND FRICTION STRESS MEASUREMENT IN ROLLING PROCESSES

    Henningsen, Poul; Arentoft, Mogens; Lagergren, Jonas;

    2005-01-01

    A load transducer has been developed to measure the contact forces in the deformation zone during rolling. The transducer consists of a strain gauge equipped insert, embedded in the surface of the roll. The length of the insert exceeds the contact length between material and roll. By analyzing the...

  5. Roll compaction and granulation system for nuclear fuel material

    A roll compaction and roll granulation system has been designed and fabricated to replace conventional preslugging and crushing operations typically used in the fabrication of mixed oxide nuclear fuel pellets. This equipment will be of maintenance advantage with only the compaction and granulation rolls inside containment. The prototype is being tested and the results will be reported within a year

  6. Wavelength Scanning Interferometery for large area roll to roll metrology applications in photovoltaic manufacturing environment

    Elrawemi, Mohamed; Blunt, Liam; Fleming, Leigh; Muhamedsalih, Hussam

    2014-01-01

    The wavelength scanning interferometer is currently being applied as a core metrology technology as part of the EU project NanoMend - Nanoscale Defect Detection, Cleaning and Repair for Large Area Substrates ̴500 mm width. NanoMend Project aims to develop technologies that are able to detect and correct micro and nano-scale defects in roll-to-roll produced films in order to improve product performance, yield and lifetime.

  7. Patterned Immobilization of Antibodies within Roll-to-Roll Hot Embossed Polymeric Microfluidic Channels

    Feyssa, Belachew; Liedert, Christina; Kivimaki, Liisa; Johansson, Leena-Sisko; Jantunen, Heli; Hakalahti, Leena

    2013-01-01

    This paper describes a method for the patterned immobilization of capture antibodies into a microfluidic platform fabricated by roll-to-roll (R2R) hot embossing on poly (methyl methacrylate) (PMMA). Covalent attachment of antibodies was achieved by two sequential inkjet printing steps. First, a polyethyleneimine (PEI) layer was deposited onto oxygen plasma activated PMMA foil and further cross-linked with glutaraldehyde (GA) to provide an amine-reactive aldehyde surface (PEI-GA). This step wa...

  8. Development of a rolling technology for twin-roll cast magnesium strips

    M. Ullmann; Berge, F.; Neh, K.; R. Kawalla

    2015-01-01

    With the best lightweight potential of all metallic construction materials, magnesium primarily helps to increase energy efficiency over the lifecycle of automotive and non-automotive industrial products. Yet to assess overall energy efficiency, the production process must also be taken into account. This paper provides an insight into the energy-efficient production of magnesium strips up to 0,8 mm in thickness based on twin-roll casting and strip rolling on an industrial scale, as developed...

  9. Thermoresistive Strain Sensor and Positioning Method for Roll-to-Roll Processes

    Kuan-Hsun Liao; Cheng-Yao Lo

    2014-01-01

    This study uses the Joule heating effect-generated temperature difference to monitor in real-time and localize both compressive and tensile strains for the polymer substrates used in the roll-to-roll process. A serpentine gold (Au) line was patterned on a polyethylenenaphthalate (PEN) substrate to form the strain sensor based on thermoresistive behavior. This strain sensor was then subjected to either current or voltage to induce the Joule heating effect on the Au resistor. An infrared (IR) d...

  10. Quality control of roll-to-roll processed polymer solar modules by complementary imaging methods

    Rösch, R.; Krebs, Frederik C; Tanenbaum, D.M.; Hoppe, H.

    2012-01-01

    We applied complementary imaging methods to investigate processing failures of roll-to-roll solution processed polymer solar modules based on polymer:fullerene bulk heterojunctions. For investigation of processing deficiencies in solar modules we employed dark lock-in thermography (DLIT), electro...... investigation can be divided into a fast DLIT overview of the module and a successive more detailed analysis of the suspicious region by all imaging methods....

  11. Control system for the surface quality of hot-rolled metal

    Full text: The modern ideas about quality of products are based on the principle of absolute satisfaction of the requirements and recommendations of the buyer. The presence of surface defects of steel-smelting and rolling origin is characteristic for the production of hot-rolling mill. The automatic surface inspection system (ASIS) includes two digital line video cameras for the filming of the upper and lower surface of the flat bar, a block for illumination of the upper and lower surface of the flat bar and a computer equipment. A system which secures 100 % control of the upper and lower surface of the rolled metal, detects automatically and classifies the sheet defects in the real time mode, was mounted 2003 for the first time in the domestic practice at the hot rolling mill 2000 JSC «Novolipetsk Iron & Steel Corporation» (NISC). The whole assortment of the mill 2000 was divided into five groups according to the outward appearance of the surface. The work on identifying the defects of hot-rolled metal and on widening the data base of knowledge of ASIS was continued after the guarantee tests. More than ten thousand images of defects were added to the data base during the year. key words: hot-rolling sheet, surface quality control, data base of defects

  12. ROLLING REVISITED: USING ROLLING TO ASSESS AND TREAT NEUROMUSCULAR CONTROL AND COORDINATION OF THE CORE AND EXTREMITIES OF ATHLETES

    Hoogenboom, Barbara J.; Voight, Michael L.

    2015-01-01

    Rolling is a movement pattern seldom used by physical therapists for assessment and intervention with adult clientele with normal neurologic function. Rolling, as an adult motor skill, combines the use of the upper extremities, core, and lower extremities in a coordinated manner to move from one posture to another. Rolling is accomplished from prone to supine and supine to prone, although the method by which it is performed varies among adults. Assessment of rolling for both the ability to co...

  13. Roll-to-Roll Nanomanufacturing of Hybrid Nanostructures for Energy Storage Device Design.

    Oakes, Landon; Hanken, Trevor; Carter, Rachel; Yates, William; Pint, Cary L

    2015-07-01

    A key limitation to the practical incorporation of nanostructured materials into emerging applications is the challenge of achieving low-cost, high throughput, and highly replicable scalable nanomanufacturing techniques to produce functional materials. Here, we report a benchtop roll-to-roll technique that builds upon the use of binary solutions of nanomaterials and liquid electrophoretic assembly to rapidly construct hybrid materials for battery design applications. We demonstrate surfactant-free hybrid mixtures of carbon nanotubes, silicon nanoparticles, MoS2 nanosheets, carbon nanohorns, and graphene nanoplatelets. Roll-to-roll electrophoretic assembly from these solutions enables the controlled fabrication of homogeneous coatings of these nanostructures that maintain chemical and physical properties defined by the synergistic combination of nanomaterials utilized without adverse effects of surfactants or impurities that typically limit liquid nanomanufacturing routes. To demonstrate the utility of this nanomanufacturing approach, we employed roll-to-roll electrophoretic processing to fabricate both positive and negative electrodes for lithium ion batteries in less than 30 s. The optimized full-cell battery, containing active materials of prelithiated silicon nanoparticles and MoS2 nanosheets, was assessed to exhibit energy densities of 167 Wh/kgcell(-1) and power densities of 9.6 kW/kgcell(-1). PMID:26053115

  14. Roll-to-roll embossing of optical linear Fresnel lens polymer film for solar concentration.

    Zhang, XinQuan; Liu, Kui; Shan, Xuechuan; Liu, Yuchan

    2014-12-15

    Roll-to-roll manufacturing has been proven to be a high-throughput and low-cost technology for continuous fabrication of functional optical polymer films. In this paper, we have firstly studied a complete manufacturing cycle of linear Fresnel lens polymer film for solar concentration in the aspects of ultra-precision diamond machining of metal roller mold, roll-to-roll embossing, and measurement on film profile and functionality. A metal roller mold patterned with linear Fresnel lenses is obtained using single point diamond turning technique. The roller mold is installed onto a self-developed roll-to-roll UV embossing system to realize continuous manufacturing of linear Fresnel lens film. Profile measurement of the machined roller mold and the embossed polymer film, which is conducted using a stylus profilometer, shows good agreement between measured facet angles with designed ones. Functionality test is conducted on a solar simulation system with a reference solar cell, and results show that strong light concentration is realized. PMID:25607497

  15. 75 FR 16504 - Hot-Rolled Flat-Rolled Carbon-Quality Steel Products From Brazil, Japan, and Russia

    2010-04-01

    ... (``Commerce'') issued an antidumping duty order on imports of hot- rolled steel from Japan (64 FR 34778... duty order on hot-rolled steel from Brazil (70 FR 30417, May 26, 2005), the antidumping duty orders on hot-rolled steel from Brazil and Japan (70 FR 30413, May 26, 2005), and the suspended investigation...

  16. Analytical inverse solution for coupled thermoelastic problem for the evaluation of contact stress during steel strip rolling

    WEISZ-PATRAULT, Daniel; Ehrlacher, Alain; Legrand, Nicolas

    2013-01-01

    Knowledge of the contact stress between roll and strip is a critical factor in modern, high-speed rolling mills. Previously two inverse analytical methods have been developed to determine the elastic contact stress on the one hand and the heat flux or the temperature in the whole roll (and especially at the surface) on the other hand, by measuring the stress tensor inside the roll body with fibre optics and by measuring the temperature with a thermocouple fully embedded at only one point insi...

  17. Investigations upon the indefinite rolls quality assurance in multiple regression analysis

    The rolling rolls quality has been enhanced mainly due to the improvements of the chemical compositions of rolls materials. The realization of an optimal chemical composition can constitute a technical efficient mode to assure the exploitation properties, the material from which the rolling mills rolls are manufactured having a higher importance in this sense. This paper continues to present the scientifically results of our experimental research in the area of the rolling rolls. The basic research contains concrete elements of immediate practical utilities in the metallurgical enterprises, for the quality improvements of rolls, having in last as the aim the durability growth and the safety in exploitation. This paper presents an analysis of the chemical composition, the influences upon the mechanical properties of the indefinite cast iron rolls. We present some mathematical correlations and graphical interpretations between the hardness (on the working surface and on necks) and the chemical composition. Using the double and triple correlations which is really helpful in the foundry practice, as it allows us to determine variation boundaries for the chemical composition, in view the obtaining the optimal values of the hardness. We suggest a mathematical interpretation of the influence of the chemical composition over the hardness of these indefinite rolling rolls. In this sense we use the multiple regression analysis which can be an important statistical tool for the investigation of relationships between variables. The enunciation of some mathematically modeling results can be described through a number of multi-component equations determined for the spaces with 3 and 4 dimensions. Also, the regression surfaces, curves of levels and volumes of variations can be represented and interpreted by technologists considering these as correlation diagrams between the analyzed variables. In this sense, these researches results can be used in the engineers collectives of the

  18. Calculation and Analysis of Temperature Distribution in Hot Rolling Strip

    Kaixiang Peng

    2013-07-01

    Full Text Available Modern steel grades require constant and reproducible production conditions both in the hot strip mill and in the cooling section to achieve constant material properties along the entire strip length and from strip to strip. Calculation of the temperature in final rolling process always utilizes factors such as the work piece's inner organizational structure, plastic deformation, and it's variations of properties and so on, also as well as the physical parameters such as gauge, shape, etc. In this paper, a finite element model is constructed for the temperature field in a rolling process. The temperature field of strip steel is modeled with a 3-D finite element analysis (FEA structure, simultaneously considering the distribution of the work roll temperature. Then the distribution of field is simulated numerically. From the model, the temperature contours can be obtained by analysis of the temperature distribution of contact area. At the same time, the distribution of temperature in any position at any time can be acquired. These efforts provide the reliable parameters for the later finishing temperature and shape control.  

  19. Microstructure evolution and grain refinement in asymmetrically rolled aluminium

    Aluminium alloy sheets were asymmetrically rolled and annealed. Asymmetric rolling was applied by imposing different velocity ratios between the top and bottom rolls, from 1 to 1.5. After cold rolling, the microstructures of various samples were analysed by electron back scatter diffraction, whereas the mechanical properties were characterized by stress–strain curves and microhardness measurements. The asymmetrical rolling process was examined as an alternative method to obtain fine- or even ultrafine-grained aluminium. The main purpose of this paper is to describe, qualitatively and quantitatively, the influence of asymmetrical rolling on microstructure evolution. Grain size, misorientation, image quality factor and other parameters were characterized and analysed in some detail. In the present study, a unique approach has been used for the first time to examine the possibility of applying the asymmetric rolling process in the preparation of materials with controlled heterogeneity

  20. Troll, a Language for specifying Dice-rolls

    Mogensen, Torben Ægidius

    2009-01-01

    Dice are used in many games, and often in fairly complex ways that make it difficult to unambiguously describe the dice-roll mechanism in plain language. Many role-playing games, such as Dungeons & Dragons, use a formalised notation for some instances of dice-rolls. This notation, once explained...... natural language to describe rolls. Even Dungeons & Dragons use formal notation only for some of the dice-roll methods used in the game. Hence, a more complete notation is in this paper proposed, and a tool for pseudo-random rolls and (nearly) exact probability calculations is described. The notation...... is called "Troll", combining the initial of the Danish word for dice ("terninger") with the English word "roll". It is a development of the language Roll described in an earlier paper. The present paper describes the most important features of Troll and its implementation....

  1. ROLLING PROCESS WITH OHSAS AND TEXTURE FORMATION– A REVIEW

    P. CHANDRAMOHAN

    2009-03-01

    Full Text Available Rolling is a mechanical treatment, which plays an important part in the processing of ferrous and nonferrous alloys. Texturing is an important phenomenon that occurs after rolling process. Preferred orientation increases the strength of the material enormously. Hence the research is focused on the rolling studies and the texture formation, which occurs after rolling process. This review mainly focuses on rolling process carried out in different alloys. It also highlights the analysis made on various rolling parameters for improving the mechanical properties. Texture studies carried on various ferrous and non-ferrous alloys; particularly in nitrogen alloyed duplex stainless steel is discussed. Finally the need for implementation of occupational health and safety during a thermomechanical treatment is also discussed. The state of art in this field is encouraging and showing positive signs of commercializing rolled nitrogen alloyed duplex stainless steel after proper texture control.

  2. Roll control resonance test vehicle (RCRTV) system postflight evaluation report

    Kryvoruka, J.K.

    1973-03-01

    This report presents the flight test results for a reentry vehicle spin-fin roll control system. The test vehicle, designated the Roll Control Resonance Test Vehicle, was flight tested on May 10, 1972, at the Sandia Laboratories Tonopah Test Range. The purpose of the flight were (1) to demonstrate and evaluate the capability of the control system to overcome a roll resonance flight instability and (2) to confirm the analytic predictions of system performance. The flight test vehicle had built-in asymmetries which, without roll control, would have caused a persistent roll resonance instability to occur. The test was successful in that all systems functioned properly and all program and flight test objectives were accomplished. Flight test data presented herein confirm analytic predictions and flight simulation methods. Results show that the system maintained roll rate control and prevented the roll resonance instability.

  3. Numerical simulation of wear of basalt lava spinning rolls

    A. Lisiecki

    2006-08-01

    Full Text Available Purpose: of this paper: Results of the study of wear phenomena of cascade spinning rolls during stone woolproduction process are described.Design/methodology/approach: The study was based on direct process observations, chemical analysis andtemperature measurements of basalt lava, metallographic examinations of the spinning rolls deposits. It was showedthat the deposits of spinning rolls are worn in very different way, depending on the roll position in rolls cascade.Findings: Predominant wear phenomena of the fully austenitic Grade 310 deposit of spinning roll no 1 is moltenbasalt lava corrosion-oxidation accompanied by low and high cycle thermal fatigue, high temperature basalt lavaerosion at low velocity of basalt lava stream impinging the working surface at high angle. Predominant wearphenomena of the austenitic-ferritic Grade S32304 deposit of spinning roll no 2 is high temperature basalt lava erosionat very high velocity of lava stream impinging the working surface at high angle what is the cause of much faster wearof then spinning roll no 1. High temperature erosion wear is accompanied by molten basalt lava corrosion-oxidationand low and high cycle thermal fatigue processes. Predominant wear phenomena of the austenitic-ferritic GradeS32304 deposits spinning roll no 3 and roll no 4 is high temperature basalt lava abrasion as sprayed by rolls no 1 andno 2 fibers of solidifying basalt lava impinge the working surface of spinning rolls no 3 and no 4.Research limitations/implications: The mechanisms of high temperature erosion demands further investigationsand detailed studies.Practical implications: The wear resistance of basalt lava spinning rolls can be increased.Originality/value: The mechanisms of surface layer wear of basalt lava spinning rolls were determined.

  4. Properties of hot rolled steels for enamelling

    The results of an investigation of the structure and properties of experimental produced hot rolled steels suitable for enamelling are presented in the paper. Hot rolled steels for enamelling represent a special group of the steels for conventional enamelling. Their quality has to be adapted to the method and conditions of enamelling. Therefore, these steels should meet some specific requirements. In addition to usual investigation of the chemical composition and mechanical properties, microstructure and quality of the steel surface also were investigated. The basic aim was to examine steels capability for enamelling, i. e. steels resistance to the fish scales phenomena, by trial enamelling, as well as quality of the steel - enamel contact surface, to evaluate the binding. Also, the changes of the mechanical properties, especially the yield point, during thermal treatment, as a very specific requirement, were investigated, by simplified method. Good results were obtained confirming the steels capability for enamelling. (Original)

  5. Look! It's Rock'n'roll!

    Lindelof, Anja

    2007-01-01

    third, the musicianship. I argue that television helped shape a heightened awareness of genre distinction within the field of popular music by emphasizing differences in visual impressions and performance attitudes, even before an awareness of genre became manifest stylistically in the music itself....... Project MUSE® - View CitationMLAAPAChicagoEndnote -------------------------------------------------------------------------------- Anja Mølle Lindelof. "Look! It's Rock'n'roll! How television participated in shaping the visual genre conventions of popular music." Music, Sound, and the Moving Image 1......, and dates. Consult your library or click here for more information on citing sources. -------------------------------------------------------------------------------- Anja Mølle Lindelof. (2007). Look! it's rock'n'roll! how television participated in shaping the visual genre conventions of popular...

  6. Dynamics and Stability of Rolling Viscoelastic Tires

    Potter, Trevor [Univ. of California, Berkeley, CA (United States)

    2013-04-30

    Current steady state rolling tire calculations often do not include treads because treads destroy the rotational symmetry of the tire. We describe two methodologies to compute time periodic solutions of a two-dimensional viscoelastic tire with treads: solving a minimization problem and solving a system of equations. We also expand on work by Oden and Lin on free spinning rolling elastic tires in which they disovered a hierachy of N-peak steady state standing wave solutions. In addition to discovering a two-dimensional hierarchy of standing wave solutions that includes their N-peak hiearchy, we consider the eects of viscoelasticity on the standing wave solutions. Finally, a commonplace model of viscoelasticity used in our numerical experiments led to non-physical elastic energy growth for large tire speeds. We show that a viscoelastic model of Govindjee and Reese remedies the problem.

  7. Slipping and rolling on an inclined plane

    Aghamohammadi, Cina [Department of Electrical Engineering, Sharif University of Technology, PO Box 11365-11155, Tehran (Iran, Islamic Republic of); Aghamohammadi, Amir, E-mail: mohamadi@alzahra.ac.ir [Department of Physics, Alzahra University, Tehran 19938-91176 (Iran, Islamic Republic of)

    2011-07-15

    In the first part of the paper, using a direct calculation two-dimensional motion of a particle sliding on an inclined plane is investigated for general values of friction coefficient ({mu}). A parametric equation for the trajectory of the particle is also obtained. In the second part of the paper, the motion of a sphere on the inclined plane is studied. It is shown that the evolution equation for the contact point of a sliding sphere is similar to that of a point particle sliding on an inclined plane whose friction coefficient is 7/2 {mu}. If {mu} > 2/7 tan {theta}, for any arbitrary initial velocity and angular velocity, the sphere will roll on the inclined plane after some finite time. In other cases, it will slip on the inclined plane. In the case of rolling, the centre of the sphere moves on a parabola. Finally the velocity and angular velocity of the sphere are exactly computed.

  8. Die Rolle von Mangan bei neurodegenerativen Erkrankungen

    Aaron B. Bowman

    2014-03-01

    Full Text Available Mangan (Mn ist ein ubiquitäres essenzielles Spurenelement, das für normales Wachstum, Entwicklung und zelluläre Homöostase erforderlich ist. Exposition gegenüber hohen Mengen an Mn verursacht eine klinische Störung, die durch extrapyramidale Symptome gekennzeichnet ist und dem idiopathischen Parkinson-Syndrom (IPS ähnelt. Der vorliegende Übersichtsartikel konzentriert sich auf die Rolle verschiedener Transporter bei der Aufrechterhaltung der Mn-Homöostase im Gehirn sowie die aktuellen methodologischen Fortschritten bei der Echtzeitbestimmung des intrazellulären Mn-Gehalts. Wir geben außerdem einen Überblick über die Rolle von Mn beim IPS, diskutieren die Ähnlichkeiten (und Unterschiede zwischen Manganismus und IPS und den Zusammenhang zwischen α-Synuclein und Mn-bedingter Proteinaggregation sowie zwischen mitochondrialen Funktionsstörungen, Mn und PS. In weiteren Abschnitten des Übersichtsartikels behandeln wir den Zusammenhang zwischen Mn und der Huntington-Krankheit (HK mit Schwerpunkt auf der Funktion von Huntingtin und der möglichen Rolle einer veränderten Mn-Homöostase und der Toxizität von Mn bei HK. Wir schließen mit einer kurzen Übersicht über die mögliche Rolle von Mn bei der Entstehung der Alzheimer-Krankheit (AK, der Amyotropen Lateralsklerose (ALS und von Prionenerkrankungen. Wann immer möglich besprechen wir die mechanistischen Gemeinsamkeiten zwischen Mn-induzierter Neurotoxizität und neurodegenerativen Störungen.

  9. Probabilistic Aspect of Rolling Bearings Durability

    Styp-Rekowski, Michał

    2007-01-01

    Many factors generate situations that real dimensions of each machine elements are different from nominal ones. In the case of rolling bearings elements mentioned disagreements are small - their values are rank of micrometers. However, such small differences can generate significant changes of operational features of bearings. The analysis of influence of ball dimensional deviation on load distribution in ball bearings is presented in this paper. The probability of occurrence of ball diameter...

  10. The rolling problem: overview and challenges

    Chitour, Yacine; Molina, Mauricio Godoy; Kokkonen, Petri

    2013-01-01

    In the present paper we give a historical account -ranging from classical to modern results- of the problem of rolling two Riemannian manifolds one on the other, with the restrictions that they cannot instantaneously slip or spin one with respect to the other. On the way we show how this problem has profited from the development of intrinsic Riemannian geometry, from geometric control theory and sub-Riemannian geometry. We also mention how other areas -such as robotics and interpolation theor...

  11. Zur Rolle der Lehrperson beim kooperativen Lernen

    Pauli, Christine; Reusser, Kurt

    2000-01-01

    Trotz des Vorliegens einer umfangreichen Forschungsliteratur zum kooperativen und selbständigen Lernen gibt es bislang nur wenige Publikationen zur Rolle und Wirksamkeit von Lehrpersonen bei Partner- und Gruppenarbeiten bzw. bei der Initiierung und Begleitung von schüleraktiven Lerndialogen. Bekannt ist dagegen, dass längst nicht alle in kooperativen Arrangements stattfindenden Lerndialoge und Interaktionen jene Qualitätsmerkmale aufweisen, von denen Pädagogen und Lehrpersonen gerne ausgehen....

  12. Rolling Bearing Life Prediction, Theory, and Application

    Zaretsky, Erwin V.

    2013-01-01

    A tutorial is presented outlining the evolution, theory, and application of rolling-element bearing life prediction from that of A. Palmgren, 1924; W. Weibull, 1939; G. Lundberg and A. Palmgren, 1947 and 1952; E. Ioannides and T. Harris, 1985; and E. Zaretsky, 1987. Comparisons are made between these life models. The Ioannides-Harris model without a fatigue limit is identical to the Lundberg-Palmgren model. The Weibull model is similar to that of Zaretsky if the exponents are chosen to be identical. Both the load-life and Hertz stress-life relations of Weibull, Lundberg and Palmgren, and Ioannides and Harris reflect a strong dependence on the Weibull slope. The Zaretsky model decouples the dependence of the critical shear stress-life relation from the Weibull slope. This results in a nominal variation of the Hertz stress-life exponent. For 9th- and 8th-power Hertz stress-life exponents for ball and roller bearings, respectively, the Lundberg- Palmgren model best predicts life. However, for 12th- and 10th-power relations reflected by modern bearing steels, the Zaretsky model based on the Weibull equation is superior. Under the range of stresses examined, the use of a fatigue limit would suggest that (for most operating conditions under which a rolling-element bearing will operate) the bearing will not fail from classical rolling-element fatigue. Realistically, this is not the case. The use of a fatigue limit will significantly overpredict life over a range of normal operating Hertz stresses. Since the predicted lives of rolling-element bearings are high, the problem can become one of undersizing a bearing for a particular application.

  13. Boundary friction on molecular lubricants: rolling mode?

    A theoretical model is proposed for low-temperature friction between two smooth rigid solid surfaces separated by lubricant molecules, admitting their deformations and rotations. The appearance of different modes of energy dissipation (by 'rocking' or 'rolling' of lubricants) at slow relative displacement of the surfaces is shown to be accompanied by stick-and-slip features and reveals a nonmonotonic (mean) friction force vs external load

  14. Lokalpolitikeres rolle og råderum

    Holm Pedersen, Lene; Houlberg, Kurt; Hansen, Sune Welling; Olsen, Asmus Leth; Bordacconi, Mats Joe

    I en ny og omfattende undersøgelse fra KORA og CBS er alle landets lokalpolitikere blevet spurgt om, hvordan de oplever deres rolle og råderum. Undersøgelsen belyser blandt andet, hvordan arbejdsvilkår og indflydelsesmuligheder er i dag, og hvordan vilkår og muligheder er blevet ændret de senere år....

  15. Rolling circle amplification of metazoan mitochondrialgenomes

    Simison, W. Brian; Lindberg, D.R.; Boore, J.L.

    2005-07-31

    Here we report the successful use of rolling circle amplification (RCA) for the amplification of complete metazoan mt genomes to make a product that is amenable to high-throughput genome sequencing techniques. The benefits of RCA over PCR are many and with further development and refinement of RCA, the sequencing of organellar genomics will require far less time and effort than current long PCR approaches.

  16. ANALYSIS OF HEAT TRANSFER OF WORK ROLL COOLING IN HOT ROLLING

    Marcio Rodrigo Solimani

    2013-10-01

    Full Text Available The roll cooling in Hot Rolling of flats directly affects two fundamental characteristics of the rolls:.the durability due to surface degradation. The other is the thermal expansion, which affects the shape and dimensions of the strip. Cooling is done by water jets that need to be properly adjusted. The determination of heat transfer coefficients is essential to optimize the process and thus increase its durability and quality of the strip. Results of experimental and numerical effects of cooling using a water jet fan-shaped on a prototype roll at temperatures between 50°C and 350°C are performed. Water pressure, nozzle type and the position along the length of the fan-shaped (center and edge influence the efficiency of roll cooling. The maximum value found in the coefficient of heat transfer was 6.0 kW/m2°C, and a 14.3% difference between the center and end of the jet fan-shaped is observed.

  17. Texture Evolution of a Non-oriented Electrical Steel Cold Rolled at Directions Different from the Hot Rolling Direction

    He, Youliang; Hilinski, Erik; Li, Jian

    2015-11-01

    With the objective of optimizing the crystallographic texture of non-oriented electrical steel, i.e., reducing the //ND and //RD fibers and promoting the //ND texture, a new rolling scheme was proposed and tested, in which the cold rolling direction (CRD) was intentionally inclined at an angle to the hot rolling direction (HRD) in order to change the orientation flow paths during cold rolling and alter the final texture of the annealed sheets. A non-oriented electrical steel containing 0.88 wt pct Si was hot rolled using conventional routes and annealed, and a number of rectangular plates were cut from the hot band with the longitudinal directions inclined at various angles, i.e., 0, 15, 30, 45, 60, 75, and 90 deg, to the HRD. These plates were then cold rolled along the longitudinal directions with a thickness reduction of 72 pct. The cold-rolled samples were annealed, temper rolled and annealed again (final annealing). The texture evolution during hot rolling, hot band annealing, cold rolling, and final annealing was characterized by electron backscatter diffraction and X-ray diffraction techniques. By changing the CRD with respect to the HRD, the initial texture and the orientation flow paths were altered, which resulted in apparent differences in the textures as compared to conventional cold rolling. After temper rolling and final annealing, the recrystallization textures consisted of mainly a //ND fiber and there was almost no //ND fiber. The sample cold rolled at an angle of 60 deg to the HRD had the strongest texture (intensity almost 2× of conventional rolling) with a maximum at the cube {001} orientation—a magnetically favorable orientation for non-oriented electrical steels.

  18. Rolling friction—models and experiment. An undergraduate student project

    In this paper the rolling friction (rolling resistance) model is studied theoretically and experimentally in undergraduate level fundamental general physics courses. Rolling motions of a cylinder along horizontal or inclined planes are studied by simple experiments, measuring deformations of the underlay or of the rolling body. The rolling of a hard cylinder on a soft underlay as well as of a soft cylinder on a hard underlay is studied. The experimental data are treated by the open source software Tracker, appropriate for use at the undergraduate level of physics. Interpretation of results is based on elementary considerations comprehensible to university students—beginners. It appears that the commonly accepted model of rolling resistance based on the idea of a warp (little bulge) on the underlay in front of the rolling body does not correspond with experimental results even for the soft underlay and hard rolling body. The alternative model of the rolling resistance is suggested in agreement with experiment and the corresponding concept of the rolling resistance coefficient is presented. In addition to the obtained results we can conclude that the project can be used as a task for students in practical exercises of fundamental general physics undergraduate courses. Projects of similar type effectively contribute to the development of the physical thinking of students. (paper)

  19. Large-scale Roll-to-Roll Fabrication of Organic Solar Cells for Energy Production

    Hösel, Markus

    efficiencies beyond 10% could be achieved. This dissertation describes process workflows and roll-to-roll (R2R) fabrication methods for upscaling the OPV technology to solar module sizes that enable real power production even at efficiencies ... solar park based on OPV modules. Infinity modules with a length of 100m (width 0.3 m) were rolled out and taped onto a wooden structure. The maximum power output of six parallel-connected modules with a total active area of 88.2m2 was beyond 1.3 kW while having energy payback times P1 year. Alternative...... installation concepts such as a balloon or special designed solar tubes on land or water were proved to be functional as well. Solar tubes with Infinity modules of around 200W generated 18 kWh in 5 weeks. The energy was fed back into the Danish power grid. The dissertation contains a brief introduction...

  20. Development of polymers for large scale roll-to-roll processing of polymer solar cells

    Carlé, Jon Eggert

    platform for polymer development. PSC devices based on PDTSTTz-4 and PCBM were produced using the laboratory roll coater and through optimerization of the processing parameters a PCE of 2.95 % at ambient condition. This efficiency is among the highest obtained on flexible ITO-free substrates using slot......Development of polymers for large scale roll-to-roll processing of polymer solar cells Conjugated polymers potential to both absorb light and transport current as well as the perspective of low cost and large scale production has made these kinds of material attractive in solar cell research. The...... and how this affects the PSC parameters are presented. It is generally found that it is possible to synthetically control the absorption spectrum of conjugated polymer systems. One way to alter the spectrum is by incorporating alternating donor-acceptor motifs, resulting in an additional optical...

  1. Preform design of large sized profile ring rolling using main roll

    This paper introduces a preform design method for a ring rolling process with an outer step. Underfilling is one of the general defects of the profile ring rolling process. It occurs when the deformation amount is small or step depth of the profiled region is large. To prevent underfilling, increasing the deformation amount or using a preform of size similar to that of the final product are required. Furthermore, the filling limit equation is suggested based on the shape factor and deformation ratio for preventing defects in the products. The filling limit equation has been derived through finite element analyses and production tests for four different cases. For verifying the suggested method, realsized profile rolling tests were performed, and test results were compared with the predictions of the equation

  2. Fatigue Behavior of High Speed Steel Roll Materials for Hot Rolling by Laser Impacting

    ZHOU Li; SUN Da-le; LIU Chang-sheng; WU Qiong

    2006-01-01

    The fatigue behavior of high speed steel (HSS) roll materials for hot rolling was researched under water-cooling conditions by laser impacting. The microstructure of HSS sample and the morphologies of fatigue samples were observed by scanning electron microscope. The phase structure was detected by XRD. The morphology of situ oxide scale was observed by optical microscope, and the expansion coefficient was measured by TGA. The experiment results indicate that the cracks come into being at the carbide-matrix interface, but there are no cracks in the matrix after many times of laser impacting treatment, for the situ sample taken from the fractured roll surface, big carbides are more sensitive to the fatigue, and peel off prior to small ones. The relevant fatigue mechanisms are also discussed.

  3. Rolls-Royce digital Rod Control System

    Full text of publication follows: Rolls-Royce has developed a new generation of Rod Control System, based on 40 years of experience. The fifth-generation Rod Control System (RCS) from Rolls-Royce offers a reliable, modular design with adaptability to your preferred platform, for modernization projects or new reactors. Flexible implementation provides the option for you to keep existing cabinets, which permits you to optimize installation approach. Main features for the power part: - Control Rod Drive Mechanism (CRDM) type: 3-coil. - Independent control of each sub-bank. - Each sub-bank is controlled by a cycler unit and 3 identical power racks, each including 4 identical power modules and a common power-supply module. - Coil-per-coil digital control: each power module embeds power-conversion, current-control, and current-monitoring functions for one coil. Control and monitoring are carried out by separate electronics in the module. Current is digitized and fully monitored by means of min-max templates. - A double-hold function is included: a power module assigned to a gripper will activate its coil if a fault risking to cause a reactor trip occurs. - Power modules are standardized, hot-pluggable and self-configured: a power module includes a set of parameters for each type of coil SG, MG, LC. The module recognizes the rack it is plugged in, and chooses automatically parameters to be used. Main benefits: - Reduced operational, maintenance, training, and inventory costs: standardization of power modules and integration of control and monitoring on the same PC-card lead to a drastic reduction of spare part types, and simplification of the system. - Easy maintenance: - Replacement of a power module solves nearly all failures due to current control or monitoring for a coil. It is done instantly thanks to hot-plug capability. - On the front plate of power-modules, LEDs provide useful information for diagnostic: current setpoint from cycler, output current bar

  4. Rolls-Royce digital Rod Control System

    Pouillot, M. [Rolls-Royce Civil Nuclear SAS (France)

    2010-07-01

    Full text of publication follows: Rolls-Royce has developed a new generation of Rod Control System, based on 40 years of experience. The fifth-generation Rod Control System (RCS) from Rolls-Royce offers a reliable, modular design with adaptability to your preferred platform, for modernization projects or new reactors. Flexible implementation provides the option for you to keep existing cabinets, which permits you to optimize installation approach. Main features for the power part: - Control Rod Drive Mechanism (CRDM) type: 3-coil. - Independent control of each sub-bank. - Each sub-bank is controlled by a cycler unit and 3 identical power racks, each including 4 identical power modules and a common power-supply module. - Coil-per-coil digital control: each power module embeds power-conversion, current-control, and current-monitoring functions for one coil. Control and monitoring are carried out by separate electronics in the module. Current is digitized and fully monitored by means of min-max templates. - A double-hold function is included: a power module assigned to a gripper will activate its coil if a fault risking to cause a reactor trip occurs. - Power modules are standardized, hot-pluggable and self-configured: a power module includes a set of parameters for each type of coil SG, MG, LC. The module recognizes the rack it is plugged in, and chooses automatically parameters to be used. Main benefits: - Reduced operational, maintenance, training, and inventory costs: standardization of power modules and integration of control and monitoring on the same PC-card lead to a drastic reduction of spare part types, and simplification of the system. - Easy maintenance: - Replacement of a power module solves nearly all failures due to current control or monitoring for a coil. It is done instantly thanks to hot-plug capability. - On the front plate of power-modules, LEDs provide useful information for diagnostic: current setpoint from cycler, output current bar

  5. Roll-to-roll gravure with nanomaterials for printing smart packaging.

    Jung, Minhun; Kim, Junseok; Koo, Hyunmo; Lee, Wookyu; Subramanian, Vivek; Cho, Gyoujin

    2014-02-01

    Roll-to-roll (R2R) gravure is considered one of the highest throughput tools for manufacturing inexpensive and flexible ubiquitous IT devices called "smart packaging" in which NFC (near-field communication) transponder, sensors, ADC (analog-to-digital converter), simple processor and signage are all integrated on paper or plastic foils. In this review, we show R2R gravure can be employed to print smart packaging, starting from printing simple electrodes, dielectrics, capacitors, diodes and thin film transistors with appropriate nanomaterial-based inks on plastic foils. PMID:24749427

  6. Roll-to-Roll fabrication of large area functional organic materials

    Søndergaard, Roar R.; Hösel, Markus; Krebs, Frederik C

    2013-01-01

    With the prospect of extremely fast manufacture of very low cost devices, organic electronics prepared by thin film processing techniques that are compatible with roll-to-roll (R2R) methods are presently receiving an increasing interest. Several technologies using organic thin films are at the po...... research fields such as organic photovoltaics, organic thin film transistors, light-emitting diodes, polymer electrolyte membrane fuel cells, and electrochromic devices. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 000: 000–000, 2012...

  7. Roll-to-Roll Fabricated Polymer Solar Cells: Towards Low Environmental Impact and Reporting Consensus

    Larsen-Olsen, Thue Trofod

    The sun is by far the largest source of renewable energy available; consequently solar cells, which are able to convert light into electricity, have the technical potential to cover the global energy needs. Polymer solar cells (PSCs) on flexible plastic substrate have a low embodied energy and can...... be processed by fast roll-to-roll (R2R) methods, using earth abundant materials, and thus deliver the prospects to fulfil this potential. A strong polarization in PSC research efforts have led to diverging and non-comparable results: While very high power conversion efficiencies (PCEs) above 10% have...

  8. Roll Rotation Cues Influence Roll Tilt Perception Assayed Using a Somatosensory Technique

    Park, Sukyung; Gianna-Poulin, Claire; Black, F. Owen; Wood, Scott; Merfeld, Daniel M.

    2006-01-01

    We investigated how the nervous system processes ambiguous cues from the otolith organs by measuring roll tilt perception elicited by two motion paradigms. In one paradigm (tilt), eight subjects were sinusoidally tilted in roll with the axis of rotation near ear level. Stimulus frequencies ranged from 0.005 to 0.7 Hz, and the peak amplitude of tilt was 20°. During this paradigm, subjects experienced a sinusoidal variation of interaural gravitational force with a peak of 0.34 g. The second mot...

  9. Low-cost sensor tape for environmental sensing based on roll-to-roll manufacturing process

    Wang, Chiu-Yen; Paradiso, Joseph A.; Gong, Nan-wei

    2012-01-01

    We describe the concept of fabricating low-cost sensor tape for fine-grid environmental sensing based on roll-to-roll manufacturing processes. We experiment with constructing sensors and electronic connections with low-cost conductive inkjet printed copper traces. Our first attempt is to fabricate humidity sensors by spin-coating conductive polymer on sensor substrates and integrating the design with an embedded system. The humidity sensor was tested in a two-point probe and exhibits the I-V ...

  10. Production Of Tandem Amorphous Silicon Alloy Solar Cells In A Continuous Roll-To-Roll Process

    Izu, Masat; Ovshinsky, Stanford R.

    1983-09-01

    A roll-to-roll plasma deposition machine for depositing multi-layered amorphous alloys has been developed. The plasma deposition machine (approximately 35 ft. long) has multiple deposition areas and processes 16-inch wide stainless steel substrate continuously. Amorphous photovoltaic thin films (less than 1pm) having a six layered structure (PINPIN) are deposited on a roll of 16-inch wide 1000 ft. long stainless steel substrate, continu-ously, in a single pass. Mass production of low-cost tandem amorphous solar cells utilizing roll-to-roll processes is now possible. A commercial plant utilizing this plasma deposition machine for manufacturing tandem amorphous silicon alloy solar cells is now in operation. At Energy Conversion Devices, Inc. (ECD), one of the major tasks of the photovoltaic group has been the scale-up of the plasma deposition process for the production of amorphous silicon alloy solar cells. Our object has been to develop the most cost effective way of producing amorphous silicon alloy solar cells having the highest efficiency. The amorphous silicon alloy solar cell which we produce has the following layer structure: 1. Thin steel substrate. 2. Multi-layered photovoltaic amorphous silicon alloy layers (approximately 1pm thick; tandem cells have six layers). 3. ITO. 4. Grid pattern. 5. Encapsulant. The deposition of the amorphous layer is technologically the key process. It was clear to us from the beginning of this scale-up program that amorphous silicon alloy solar cells produced in wide width, continuous roll-to-roll production process would be ultimate lowest cost solar cells according to the following reasons. First of all, the material cost of our solar cells is low because: (1) the total thickness of active material is less than 1pm, and the material usage is very small; (2) silicon, fluorine, hydrogen, and other materials used in the device are abundant and low cost; (3) thin, low-cost substrate is used; and (4) product yield is high. In

  11. High-speed roll-to-roll manufacturing of graphene using a concentric tube CVD reactor

    Polsen, Erik S.; McNerny, Daniel Q.; B. Viswanath; Pattinson, Sebastian W.; A. John Hart

    2015-01-01

    We present the design of a concentric tube (CT) reactor for roll-to-roll chemical vapor deposition (CVD) on flexible substrates, and its application to continuous production of graphene on copper foil. In the CTCVD reactor, the thin foil substrate is helically wrapped around the inner tube, and translates through the gap between the concentric tubes. We use a bench-scale prototype machine to synthesize graphene on copper substrates at translation speeds varying from 25 mm/min to 500 mm/min, a...

  12. Lengthening the lifetime of roll-to-roll produced polymer solar cells

    Madsen, Morten Vesterager

    The field of polymer solar cells is a field with an exponential growth in the number of published papers. It is a field defined by a set of challenges including; efficiency, stability and processability. Before all of these challenges have been addressed; polymer solar cells will not be a......-depth morphology of polymer solar cells using ellipsometry. It was demonstrated that ellipsometry can be used as a non destructive depth profiling technique to obtain compositional morphology of the active layer of roll-to-roll coated samples. The second and third part is devoted to the study of photo...

  13. Rolling test of turbine generator by non-nuclear steam

    The object and procedure of rolling turbine generator test by non-nuclear steam in Qinshan NPP are presented. The steam source of rolling test is compared and chosen. The steam quantity during the rolling test is simply calculated. The limits of parameters of the test and the preparing for rolling of turbine generator are introduced. Procedures of rolling test are divided into three stage of speed: 600 r/min, 1200 r/min, 3000 r/min. Parameters measured as a result of rolling test, such as absolute vibration of axle, metal temperature of bearings, temperature of oil from the exit of bearings and vacuity of condenser etc, show that the design, manufacture, installation and speed control of turbine generator are satisfactory

  14. A review on hot direct rolling of hsla steel

    The evolution of economically viable high strength low alloy structural steels (HSLA) with a good weld ability is probably the most significant metallurgical achievement of the steel industry in the last few decades. In these developments during thermo mechanical processing grain refinement is achieved by refining the as rolled austenite phase prior to transformation and introducing a high density of ferrite nucleation sites during rolling. A current trend in thermo mechanical processing of steel is to integrate the rolling process with continuous casting process. The development of a direct linkage between the continuous casting machine and hot working processes is suggested by economic considerations. However, hot charge rolling (HCR) and hot direct rolling (HDR) of micro alloyed steels affect mechanical properties significantly compared with conventional controlled rolling(CCR). (author)

  15. Textures and Properties of Hot Rolled High Strength Ti-IF Steels

    GUO Yan-hui; WANG Zhao-dong; ZOU Wen-wen; LIU Xiang-hua; WANG Guo-dong

    2008-01-01

    The texture evolution in a high strength Ti-IF steel during the processing of hot rolling,cold rolling,and annealing is studied.For comparison,both ferrite rolling and austenite rolling are employed.It is found that the texture type is the.same after ferrite rolling and austenite rolling,but the texture intensity is much higher in the ferriterolled sample.Furthermore,texture characteristics at the surface are absolutely different from those at the mid-section in both ferrite rolled and austenite rolled samples,as well as under the cold rolled and annealed conditions.The shear texture {110} disappears and orientation rotates along {110} →{554}→{111}→{111}→{223} during cold rolling.Compared to the austenite rolled sample,the properties of the cold rolled and annealed sheet which is subjected to ferrite rolling are higher.

  16. The Theory and Technique of Yamuna Body Rolling

    Suzuki, Satoshi

    2013-01-01

    [Purpose] This paper provides information about the theory and technique of Yamuna Body Rolling. In order to treat physical problems, using the specialized Yamuna Body Rolling balls, people can target superficial skin, fasciae, muscle fibers, tendons, ligaments, bones, internal organs, and the nervous system by themselves. The extraordinary effect of Yamuna Body Rolling is its multidimensional elongation of muscle fibers. In addition to the regular longitudinal elongation by the conventional ...

  17. Entry Strategies to Indonesian Market Case: MoveaRoll

    Islam, Zahedul

    2013-01-01

    MoveRoll Oy, an internationally growing and expanding Finnish company located in Porvoo, has invented a unique technology to produce a paper roll conveyor which the company believes will revolutionise the paper roll handling industry. Moreover, after establishing itself in the Finnish market, the company has started expanding its business to countries like Sweden, USA, and China. Likewise, the process of expanding to the Russian market is currently underway and the company has recently launch...

  18. Fatigue Life Analysis of Rolling Bearings Based on Quasistatic Modeling

    Wei Guo; Hongrui Cao; Zhengjia He; Laihao Yang

    2015-01-01

    Rolling bearings are widely used in aeroengine, machine tool spindles, locomotive wheelset, and so forth. Rolling bearings are usually the weakest components that influence the remaining life of the whole machine. In this paper, a fatigue life prediction method is proposed based on quasistatic modeling of rolling bearings. With consideration of radial centrifugal expansion and thermal deformations on the geometric displacement in the bearings, the Jones’ bearing model is updated, which can pr...

  19. Parametric Roll Resonance Monitoring using Signal-based Detection

    Galeazzi, Roberto; Blanke, Mogens; Falkenberg, Thomas; Poulsen, Niels Kjølstad; Violaris, Nicos; Storhaug, Gaute; Huss, Mikael

    2015-01-01

    Extreme roll motion of ships can be caused by several phenomena, one of which is parametric roll resonance. Several incidents occurred unexpectedly around the millennium and caused vast fiscal losses on large container vessels. The phenomenon is now well understood and some consider parametric roll a curiosity, others have concerns. This study employs novel signal-based detection algorithms to analyse logged motion data from a container vessel (2800~TEU) and a large car and truck carrier (LCT...

  20. Higher order slow-roll predictions for inflation

    We study the WKB approximation beyond leading order for cosmological perturbations during inflation. To first order in the slow-roll parameters, we show that an improved WKB approximation leads to analytical results agreeing to within 0.1% with the standard slow-roll results. Moreover, the leading WKB approximation to second order in the slow-roll parameters leads to analytical predictions in qualitative agreement with those obtained by the Green's function method

  1. Preferred Orientation of MnS Inclusions in Rolled Steel

    Mardinly, A. John; van Vlack, Lawrence H.; Hosford, William F.

    1993-01-01

    The preferred orientation of MnS inclusions in hot-rolled steel was studied by electron diffraction. Specimens of resulfurized steel were examined after casting and after hot rolling to true strains of 0.5, 1.0 and 1.5. After rolling, the orientations of the inclusions tended toward an ideal 〈100〉 {001}. Only a moderate correlation between the final inclusion shape and orientation was found.

  2. Advanced hot rolling strategies for IF and TRIP steels

    Elsner, A.

    2005-01-01

    Steel producers are forced to reduce the production cost on the one hand and increase the performances of the products on the other hand, to maintain or even increase their market share. A likely method to save on production costs is to cut down the rather long production chain for conventional cold rolled strip, and to substitute certain cold rolled steel grades by hot rolled steel. Certainly this can rarely be achieved for exposed parts, requiring a perfect surface finish, whereas for unexp...

  3. Measurements of normal and frictional forces in a rolling process

    Henningsen, Poul; Arentoft, Mogens; Wanheim, Tarras

    2006-01-01

    To improve the quality of frictional data and to validate the simulations in rolling, a load transducer for measuring normal and frictional stresses in the deformation zone has been developed. The transducer consists of a strain-gauge-equipped insert embedded in the surface of the roll. The lengt...... material between the transducer and roll. The transducer is tested at laboratory conditions and is expected to be running in industrial conditions in 2004....

  4. Measurements of Normal and Friction Forces in a Rolling Process

    Henningsen, Poul; Arentoft, Mogens; Wanheim, Tarras

    2004-01-01

    To improve the quality of frictional data and to validate the simulations in rolling, a load transducer for measuring normal and friction stresses in the deformation zone has been developed. The transducer consists of a strain gauge equipped insert embedded in the surface of the roll. The length ...... material between transducer and roll. The transducer is tested at laboratory conditions and is expected to be running in industrial conditions in 2004....

  5. High speed twin roll casting of 6061 alloy strips

    T. Haga; H. Sakaguchi; Watari, H; S. Kumai

    2008-01-01

    Purpose: of this paper is to clear the possibility of high speed roll casting of thin strips of two aluminum alloys:6061 and recycled 6061. Mechanical properties of the roll cast 6061 and recycled 6061 strips were investigated inthe frame of this purpose.Design/methodology/approach: Methods used in the present study were high speed twin roll caster and lowtemperature casting. These methods were used to realize rapid solidification and increase the casting speed.Findings: are that 6061 and rec...

  6. Precision Manufacturing of Imprint Rolls for the Roller Imprinting Process

    Vijayaraghavan, Athulan; Dornfeld, David A; Kim, Chang-Ju

    2008-01-01

    The roller imprinting process is being developed for the efficient and accurate fabrication of microfluidic devices. As the precision of the imprinted features is dependent on the features of the imprint rolls used in the process, it is critical that the rolls are manufactured very accurately, conforming closely to their design. It is also important that imprint rolls are manufactured rapidly and cost-effectively to control the cost and lead-time of roller imprinting. This paper looks at the ...

  7. Effect of rolling reduction on the development of rolling and recrystallization textures in Al-Mg alloys

    Endou, S.; Inagaki, H. [Shonan Inst. of Tech., Fujisawashi (Japan)

    2002-07-01

    In order to investigate the effect of Mg content on the development of the rolling textures in Al pure Al, Al-3% Mg alloy and Al-5% Mg alloy were cold rolled by varying rolling reductions up to 97%. Their rolling textures were investigated by the orientation distribution function analysis. The extent of work hardening introduced by cold rolling was estimated by the hardness measurements. It was found that, at all rolling reductions, the main orientations of the rolling textures depended strongly on the Mg content. In pure Al, {l_brace}123{r_brace} left angle 634 right angle was always the main orientation, whereas {l_brace}112{r_brace} left angle 111 right angle was most strong in the Al-3%Mg alloy. In the Al-5% Mg alloy, the development of both {l_brace}123{r_brace} left angle 634 right angle and {l_brace}112{r_brace} left angle 111 right angle were strongly suppressed, whereas {l_brace}110{r_brace} left angle 112 right angle developed remarkably. In pure Al, most of the texture development occurred at the later half of work hardening, i.e. at rolling reductions above 70%. With increasing Mg content, rolling texture tended to develop already at lower rolling reductions. Dynamic recovery, which occurred at very high rolling reductions, suppressed the development of the rolling textures. All these results strongly suggested that the formation of dislocation cell structures and shear banding are origins of the formation of these rolling textures. On annealing these specimens at 450 C for 30 min, recrystallization textures developed only in specimens having strong rolling textures, i. e. in the specimens cold rolled more than 70%. {l_brace}100{r_brace} left angle 001 right angle developed only in pure Al and in the Al-3% Mg ally, in which {l_brace}123{r_brace} left angle 634 right angle and {l_brace}112{r_brace} left angle 111 right angle were strong in the rolling textures. Recrystallization textures of the Al-5% Mg alloy was wather random. Its main orientation, {l

  8. 21 CFR 136.180 - Whole wheat bread, rolls, and buns.

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Whole wheat bread, rolls, and buns. 136.180... § 136.180 Whole wheat bread, rolls, and buns. (a) Each of the foods whole wheat bread, graham bread, entire wheat bread, whole wheat rolls, graham rolls, entire wheat rolls, whole wheat buns, graham...

  9. TECHNICAL NOTE: Multiple-degrees-of-freedom electroelastomer roll actuators

    Pei, Qibing; Rosenthal, Marcus; Stanford, Scott; Prahlad, Harsha; Pelrine, Ron

    2004-10-01

    Electroelastomers (electroactive elastomers) such as the 3M VHB 4910 acrylic adhesive films have exhibited up to 380% strain in area expansion at 5 6 kV when they are highly prestrained. By rolling highly prestrained electroelastomer films around a compression spring, we have demonstrated multifunctional electroelastomer rolls (MERs, or spring rolls) that combine load bearing, actuation, and sensing functions. We extended the design to two-degree-of-freedom (2-DOF) and 3-DOF spring rolls by patterning the electrodes to align radially on two and four circumferential spans of the rolls, respectively. Multiple-DOF spring rolls retain the linear actuation of 1-DOF spring rolls with additional bending actuation. Mathematical equations are derived to correlate the bending angle and lateral force of the rolls with the actuated stroke in one of the electroded spans. Two-DOF spring rolls with a 1.4 cm outside diameter, 6.8 cm axial length, and 11 g weight have been fabricated; these rolls have a 90° maximum actuation bending angle, 0.7 N maximum lateral force, and up to 15 N blocked axial force. Three-DOF spring rolls with a 2.3 cm outside diameter, 9.0 cm axial length, and 29 g weight exhibit a 35° maximum bending angle and 1.0 N maximum lateral force. These specifications can be modified by variations in roll parameters according to the equations. Multi-DOF spring rolls are easy to fabricate, compact, multifunctional, and mechanically robust. They represent a radically new actuation technology and may enable a number of unique applications. We have demonstrated a small walking robot, MERbot, with one 2-DOF spring roll as each of its six legs. The robot's speed is as high as 13.6 cm s-1 or two-thirds of its length per second. 'Sushi rolls' have also been fabricated: these consist of six 2-DOF springs connected in series and monolithic in structure. The sushi rolls can be driven so as to generate wavelike or serpentine motion.

  10. Annuitants Added to the Annuity Roll Processing System (ARPS)

    Office of Personnel Management — Small table showing the total Civil Service Retirement System (CSRS) and Federal Employees Retirement System (FERS) Annuitants added to the Annuity Roll Processing...

  11. FACTOR ANALYSIS OF THE ROLLING PROCESS TECHNOLOGY (part 1

    A. N. Chichko

    2011-01-01

    Full Text Available The mathematical model of multidimensional regression analysis is presented. Its practical application for rolling production is examined. The algorithm of special characteristics determination is developed.

  12. Microstructure and Texture of a Warmed Rolled IF Steel

    Viana, C. S. Da Costa; Matheus, J. R. G.; Lopes, A. M.; El-Sharawy, H. H. Aly

    2000-01-01

    Steel rolling within the temperature range intermediate between hot and cold rolling represents today a very economical and technically viable operation. The present work investigates the microstructure and the texture developed in a Ti microalloyed IF steel by rolling at 400°C and 600°C. Reductions of 40% and 60% were applied to a set of as hot rolled strip specimens part of which was subsequently annealed at 800°C for 5 minutes. Both the microstructure and the texture were examined by scann...

  13. Investigation of the Microstructure of Rolled Semi-Solid Steel

    2002-01-01

    In this paper, spring steel-60Si2Mn and stainless steel-1Cr18Ni9Ti were rolled one pass in the semi-solid state. The microstructural evolution during rolling of the steels with different solid fraction was investigated. The experimental results showed that the manner of liquid and solid phases flowing and deforming was different. During rolling, most of solid phases remained in the center of the rolled specimens, while liquid phase flowed to the edge, which resulted in the macrosegregation of liquid and solid phases. Only the amount of solid fraction reached a certain value, were the solid phases deformed and flattened.

  14. Rolling induced size effects in elastic–viscoplastic sheet metals

    Nielsen, Kim Lau

    2015-01-01

    presented revolves around the rolling induced effect of visco-plasticity (ranging hot and cold rolling) in combination with strain gradient hardening – including both dissipative and energetic contributions. To bring out first order effects on rolling at small scale, the modeling efforts are limited to flat...... energetic length parameter has negligible effect on the rolling quantities of interest, while the contribution coming from the dissipative length parameter can be dominant. Considering a slow and a fast moving sheet, respectively, convergence towards the rate independent limit is demonstrated, and a...

  15. Development and validation of thermal hydraulic code in rolling motion

    The RELAP5/MOD3.3 code was modified by adding a module calculating the effect of rolling motion and introducing new flow and heat transfer models. The thermal hydraulic code in rolling motion was developed. The experimental data were used to validate the theoretical models and calculation results. It is shown that the new flow and heat transfer models can correctly calculate the frictional resistance and heat transfer coefficients in rolling motion. The developed thermal hydraulic code can be used to simulate the thermal hydraulic system in rolling motion. (authors)

  16. Chaotic traveling rolls in Rayleigh-B\\'enard convection

    Pal, Supriyo; Kumar, Krishna; Verma, Mahendra K.; Carati, Daniele; De, Arnab K.; Eswaran, Vinayak

    2007-01-01

    In this paper we investigate two-dimensional (2D) Rayleigh-B\\'enard convection using direct numerical simulation in Boussinesq fluids of Prandtl number $P = 6.8$ confined between thermally conducting plates. We show through the simulation that in a small range of reduced Rayleigh number $r$ ($770 < r < 890$) the 2D rolls move chaotically in a direction normal to the roll axis. The lateral shift of the rolls may lead to global flow reversal of the convective motion. The chaotic traveling rolls...

  17. Twinning, dynamic recovery and recrystallization in the hot rolling process of twin-roll cast AZ31B alloy

    Highlights: → Two different types of twinning, {101-bar 2} and {101-bar 1}, occurred in the rolling process, and {101-bar 1} twins tended to be preferred sites for recrystallization. → DRV and discontinuous recrystallization dominated at moderate strain in the rolling process. → Non-basal slip was homogeneously activated at even larger strains and continuous DRX readily took place on the basis of cellular structures. - Abstract: Hot-rolling experiments with a reduction from 10% to 60% in single pass were conducted on AZ31B twin-roll cast sheets. Optical microscope (OM), electron backscattered diffraction (EBSD) tests and transmission electron microscope (TEM) were used to investigate twinning and DRV/DRX behaviors at different stage in the hot-rolling process. Two types of twinning occurred in the initial stage of hot-rolling process. DRV and discontinuous recrystallization dominated at moderate strain while continuous DRX took place homogeneously throughout original grains at the largest strains.

  18. Scalable, ambient atmosphere roll-to-roll manufacture of encapsulated large area, flexible organic tandem solar cell modules

    Andersen, Thomas Rieks; Dam, Henrik Friis; Hösel, Markus;

    2014-01-01

    Inline printing and coating methods have been demonstrated to enable a high technical yield of fully roll-to-roll processed polymer tandem solar cell modules. We demonstrate generality by employing different material sets and also describe how the ink systems must be carefully co-developed in ord......-ray machine enabling in situ studies of wet ink deposition and drying mechanisms, ultimately elucidating how a robust inline processed recombination layer is key to a high technical yield. Finally, the transfer to full roll-to-roll processing is demonstrated....... to reach the ambitious objective of a fully printed and coated 14-layer flexible tandem solar cell stack. The roll-to-roll methodologies involved are flexographic printing, rotary screen printing, slot-die coating, X-ray scattering, electrical testing and UV-lamination. Their combination enables the...

  19. Fabrication of microlens arrays on a glass substrate by roll-to-roll process with PDMS mold

    Hu, Chia-Nying; Su, Guo-Dung J.

    2009-08-01

    This paper presents a roll-to-roll method to fabricate microlens arrays on a glass substrate by using a cost-effective PDMS (Polydimethylsiloxane) mold. We fabricated microlens arrays mold, which was made by photoresist(AZ4620), on the silicon substrate by thermal reflow process, and transferred the pattern to PDMS film. Roll-to-roll system is a standard printing process whose roller is made of acrylic cylinder surrounded with the PDMS mold. UV resin was chosen to be the material to make microlens in rolling process with UV light curing. We investigated the quality of microlens arrays by changing the parameters, such as embossing pressure and rolling speed, to ensure good quality of microlens arrays.

  20. Engineering of rolled constructional microalloyed steel products

    Flexibility of the microalloyed steels on manufacturing of products with high mechanical and technological properties at not exaggerated production costs, it caused of their application for different constructions and machines in many branches of economy. It is a reason of the big interest of this steel group and the improvement of metallurgical and technological processing. In the work the examples of applications of C-Mn microalloyed steels with V and N microadditions for production of long shape products of Rp0.2 > 650 MPa and KCU2 > 57 Jcm-2 are presented. They are manufactured in the controlled rolling process. Moreover this work presents liquid metal treatment in ladlemann process and influence of ingots solidification conditions, controlled rolling of weldable plates with Nb, Ti, V and B microadditions which after quenching and tempering have Rp0.2 > 870 MPa, KV-50oC > 27 J and plastic strain ratio equals 1.2. This work also presents the energy saving rolling technology with controlled recrystallization (method of thermomechanical treatment) of improved Weldox 960 steel plates with Mb, Ti, V and B microadditions which have after high-temperature tempering Rp0.2 > 100 MPa, KV-50oC >90 J and plastic strain ratio is less than 1.2. The introduction of microalloyed constructional steels and the appropriate technology in the domestic industry will contribute to high-processed products with properties competitive to products manufactured in high-industrialized countries. Thanks to that it will be possible to increase the technical level as well as to reduce production costs and import. (author)

  1. Huddersfield's roll of honour: 1914-1922

    Stansfield, J. Margaret

    2014-01-01

    Huddersfield’s Roll of Honour 1914-1922 is a detailed account of 3,439 service personnel from Huddersfield who lost their lives during the First World War. In the Preface, HRH The Duke of York KG writes: “This publication represents the lifetime work of Margaret Stansfield who sadly passed away in 2012. Margaret spent 30 years compiling the 3,439 biographical entries giving a poignant insight into the background, working lives and families of those who selflessly left Huddersfield to fi...

  2. Equity valuation : Rolls-Royce PLC

    Fonseca, Mafalda Filipa Sousa

    2014-01-01

    The purpose of this thesis is to evaluate Rolls-Royce PLC. In order to do so, two valuation methodologies will be presented. The first one regards the Discount Cash Flow – WACC methodology, where each sector of the company is valued. By doing so, it is possible to reach a price per share of 1369 pence. Therefore, when using this methodology, the company is presented as a buying opportunity (the market yields a price of 1112 pence.) The second valuation presented and which is introduced ...

  3. B77 roll control system: summary report

    Pignolet, C.J.; Rogers, M.H.

    1979-10-01

    The B77 roll control system evolved from a cold-gas driven assembly at its inception in 1974 to a warm-gas version at the time of program cancellation in 1978. The report documents that evolvement. Included are descriptions of the analytical support calculations, the hardware, and the test results. The problems encountered and the rationale which led to design choices are detailed. Although some problems had not been resolved as of cancellation, the designs provided the capability to meet B77 requirements.

  4. Periodically fighting shake, rattle and roll

    BRUN, M.; Movchan, A. B.; Jones, I. S.

    2011-01-01

    How easy is it to suppress shake, rattle and roll in a long bridge or a skyscraper? Most practical structures are designed so that long wave resonance vibrations can be avoided. However, there are recent examples, such as the Millennium Bridge in London or the Volga Bridge in Volgograd, which show that unexpected external forces may result in large scale unwanted shake and rattle. Full scale alteration of a bridge (or a skyscraper) would not be considered as an acceptable option, unless the s...

  5. Bayesian Soft Sensing in Cold Sheet Rolling

    Dedecius, Kamil; Jirsa, Ladislav

    Praha: ÚTIA AV ČR, v.v.i, 2010. s. 45-45. [6th International Workshop on Data–Algorithms–Decision Making. 2.12.2010-4.12.2010, Jindřichův Hradec] R&D Projects: GA MŠk(CZ) 7D09008 Institutional research plan: CEZ:AV0Z10750506 Keywords : soft sensor * bayesian statistics * bayesian model averaging Subject RIV: BB - Applied Statistics, Operational Research http://library.utia.cas.cz/separaty/2010/AS/dedecius-bayesian soft sensing in cold sheet rolling.pdf

  6. Self-Aligned Metal Electrodes in Fully Roll-to-Roll Processed Organic Transistors

    Marja Vilkman

    2016-01-01

    Full Text Available We demonstrate the production of organic bottom gate transistors with self-aligned electrodes, using only continuous roll-to-roll (R2R techniques. The self-alignment allows accurate <5 µm layer-to-layer registration, which is usually a challenge in high-speed R2R environments as the standard registration methods are limited to the millimeter range—or, at best, to tens of µm if online cameras and automatic web control are utilized. The improved registration enables minimizing the overlap between the source/drain electrodes and the gate electrode, which is essential for minimizing the parasitic capacitance. The complete process is a combination of several techniques, including evaporation, reverse gravure, flexography, lift-off, UV exposure and development methods—all transferred to a continuous R2R pilot line. Altogether, approximately 80 meters of devices consisting of thousands of transistors were manufactured in a roll-to-roll fashion. Finally, a cost analysis is presented in order to ascertain the main costs and to predict whether the process would be feasible for the industrial production of organic transistors.

  7. Roll bonding steps of 6061 aluminum alloy plates during hot rolling of nuclear fuel plates

    Roll Bonding process is applied to clad the core plate (U3O8+Al), with high strength aluminum alloys during fabrication of plate type nuclear fuel elements for research reactors, and to produce many new constructions which have special uses in industrial applications. In the present work, the steps of the hot roll bonding process were studied using both microscopic examination and mechanical testing. It was found that, there is a threshold of reduction, at which the metallic bond initiates. After this point, the increasing of degree of reduction leads to increase in the bond strength. This reduction threshold was found to be 30%. The final bond strength was about 0.87 of the strength of the base 6061 aluminum alloy at the same conditions of hot working and thermal treatments. The present results showed that at least 81% reduction in thickness is required to produce the required bond between the cladding and both core plate and frame for roll bonded plates with the standard roll bonding method. (author)

  8. High-speed roll-to-roll manufacturing of graphene using a concentric tube CVD reactor

    Polsen, Erik S.; McNerny, Daniel Q.; Viswanath, B.; Pattinson, Sebastian W.; John Hart, A.

    2015-05-01

    We present the design of a concentric tube (CT) reactor for roll-to-roll chemical vapor deposition (CVD) on flexible substrates, and its application to continuous production of graphene on copper foil. In the CTCVD reactor, the thin foil substrate is helically wrapped around the inner tube, and translates through the gap between the concentric tubes. We use a bench-scale prototype machine to synthesize graphene on copper substrates at translation speeds varying from 25 mm/min to 500 mm/min, and investigate the influence of process parameters on the uniformity and coverage of graphene on a continuously moving foil. At lower speeds, high-quality monolayer graphene is formed; at higher speeds, rapid nucleation of small graphene domains is observed, yet coalescence is prevented by the limited residence time in the CTCVD system. We show that a smooth isothermal transition between the reducing and carbon-containing atmospheres, enabled by injection of the carbon feedstock via radial holes in the inner tube, is essential to high-quality roll-to-roll graphene CVD. We discuss how the foil quality and microstructure limit the uniformity of graphene over macroscopic dimensions. We conclude by discussing means of scaling and reconfiguring the CTCVD design based on general requirements for 2-D materials manufacturing.

  9. Finite-element Mathematical Modeling of Combined Processes of Hot Rolling and Plastic Bending

    Salganik, V.; Pesin, A.

    2004-06-01

    Finite-element viscoplastic mathematical model of combined process of asymmetrical rolling and plastic sheet bending has been created. Modeling of a new technology and its further introduction for a plate mill made it possible to have new expensive production — large-size bodies of revolution in the form of cylinders and cones.

  10. 周期轧管机轧辊轴受力分析%Analysis on Roll Shaft Stress of Cycle Tube Mill

    2013-01-01

    Cycle tube mill unit is primary seamless tube mill, which is suitable for tubular billet of heavy caliber and thick wall. The paper was introduced working principle and equipment composition of cycle tube mill, and analyzed process condi-tions, determination and stress of tube mill.%  周期轧管机组是最早的一种无缝管管轧机,它适用于大口径,厚壁的毛管轧制。文章介绍了周期轧管机的工作原理及设备组成,并对轧管机的工艺条件、工艺参数的确定和受力进行了分析。

  11. Effect of Rolling Route on Microstructure and Tensile Properties of Twin-Roll Casting AZ31 Mg Alloy Sheets

    Dan Luo

    2016-06-01

    Full Text Available Twin-roll casting AZ31 Mg alloy sheets have been fabricated by normal unidirectional-rolling, head-to-tail rolling, and clock-rolling, respectively. It has been demonstrated that head-to-tail rolling is the most effective to refine the microstructure and weaken the basal texture among the three rolling routes. Excellent integrated tensile properties can be obtained by the head-to-tail rolling. The yield strength, ultimate tensile strength, and plastic elongation are 196 MPa, 301 MPa, and 28.9%, respectively. The strength can benefit from the fine grains (average value of 4.0 μm of the AZ31 alloy processed by the head-to-tail rolling route, while the excellent plastic elongation is achieved owing to the weakened basal texture besides the fine grains. Results obtained here can be used as a basis for further study of some simple rolling methods, which is critical to the development of Mg alloys with high strength and plasticity.

  12. High-throughput roll-to-roll X-ray characterization of polymer solar cell active layers

    Böttiger, Arvid P.L.; Jørgensen, Mikkel; Menzel, Andreas;

    2012-01-01

    Synchrotron-based X-rays were used to probe active materials for polymer solar cells on flexible polyester foil. The active material was coated onto a flexible 130 micron thick polyester foil using roll-to-roll differentially pumped slot-die coating and presented variation in composition, thickness...... 1 cm, probing linear variations in processing and coating parameters along the foil. The demonstration shows that real-time structural characterization of roll-to-roll coating at realistic web-speeds is feasible using synchrotron radiation. Off-line characterization with lower spatial resolution...

  13. Production of 17-4PH Precipitation Hardening Stainless Steel Nozzle for Rolling Mill by Investment Casting%17-4PH沉淀硬化不锈钢轧机导槽的精密铸造

    赵竞翔; 陶小炯; 李桐; 王拓

    2012-01-01

    轧机导槽是高速线材轧机上的易损部件,采用17-4PH沉淀硬化不锈钢熔模铸造而成.该部件结构复杂、壁厚相差大,易产生缩孔、缩松缺陷;浇口处在热处理时易出现裂纹,制造工艺难度大.根据导槽零件的结构特点,优化模具设计、使用石蜡硬脂酸低温蜡制模,有效防止蜡模的变形,保证了铸件的尺寸精度和表面光洁度;通过浇注系统的优化,解决了导槽铸件的缩孔和热处理过程中的开裂缺陷,批量生产出了合格的导槽铸件.%Nozzle for rolling mill as easily failure parts for high speed wire rod mill was produced with 17-4PH precipitation hardening stainless steel by investment casting. There exists many difficulties in the manufacturing process,and shrinkage porosity (hole) often occurs in the nozzle due to its complicated structure and obvious wall thickness difference. Meanwhile, crack can be easily generated at the runner location after heat treatment. Based on the structure characteristics of the nozzle parts, through optimizing mould design and making wax-pattern with paraffin-stearic acid low-point wax as well as silica sol shell molding, deformation can be effectively avoided, and dimension accuracy and surface roughness can be improved. The shrinkage porosity (hole) and thermal crack can be eliminated by optimizing gating system. Product-volumetric qualified castings were manufactured.

  14. High speed twin roll caste for aluminum alloy thin strip

    T. Haga

    2007-09-01

    Full Text Available Purpose: In the present study, effectiveness of a high-speed twin roll caster for recycling aluminum alloy was investigated.Design/methodology/approach: The effects of the high-speed twin roll caster on alleviating the deterioration of mechanical properties by impurities were investigated. Properties of the cast strip were investigated by metalography, a tension test, and a bending test.Findings: A vertical type twin roll caster for strip casting of aluminum alloys was devised. The strip, which was thinner than 3 mm, could be cast at speeds higher than 60 m/min. Features of the twin roll casters are as below. Copper rolls were used and lubricant was not used in order to increase the casting speed. A casting nozzle was used to set the solidification length precisely. Heat transfer between melt and the roll was improved by hydrostatic pressure of the melt. Separating force was very small in order to prevent sticking of the strip to the roll. Low superheat casting was carried out in order to improve microstructure of the strip. In the present study, effectiveness of a high-speed and high-cooling rate twin roll caster of the present study for recycling aluminum alloy was investigated. Fe was added as impurity to 6063 and A356. The roll caster of the present study was useful to decrease the influence of impurity of Fe.Research limitations/implications: A high-speed twin roll caster of vertical type was designed and assembled to cast aluminum alloy thin strip.Originality/value: The results demonstrate that the high-speed twin roll caster can improve the deterioration by impurities.

  15. Curious terminal turn of rolling rings

    Jalali, Mir Abbas; Alam, Reza

    2014-01-01

    We report an unexpected reverse spiral turn in the final stage of the motion of rolling rings. It is well known that spinning disks have definite centers of rotation until they stop. While a spinning ring starts its motion with a similar kinematics, moving along a cycloidal path prograde with the direction of its rigid body rotation, the mean trajectory of its center of mass develops an inflection point so that the ring makes a spiral turn and revolves in a retrograde direction around a new center. Using high speed imaging and numerical simulations of models featuring a rolling rigid body, we show that the hollow geometry of a ring tunes the rotational air drag resistance so that the frictional force at the contact point with the ground changes its direction at the inflection point and puts the ring on a retrograde spiral trajectory. Our findings have potential applications in designing topologically new surface-effect flying objects capable of performing complex reorientation and translational maneuvers.

  16. Terminal retrograde turn of rolling rings

    Jalali, Mir Abbas; Sarebangholi, Milad S.; Alam, Mohammad-Reza

    2015-09-01

    We report an unexpected reverse spiral turn in the final stage of the motion of rolling rings. It is well known that spinning disks rotate in the same direction of their initial spin until they stop. While a spinning ring starts its motion with a kinematics similar to disks, i.e., moving along a cycloidal path prograde with the direction of its rigid body rotation, the mean trajectory of its center of mass later develops an inflection point so that the ring makes a spiral turn and revolves in a retrograde direction around a new center. Using high speed imaging and numerical simulations of models featuring a rolling rigid body, we show that the hollow geometry of a ring tunes the rotational air drag resistance so that the frictional force at the contact point with the ground changes its direction at the inflection point and puts the ring on a retrograde spiral trajectory. Our findings have potential applications in designing topologically new surface-effect flying objects capable of performing complex reorientation and translational maneuvers.

  17. Production of normalized steel plate through normalizing rolling; Producao de chapas grossas normalizadas diretamente do calor de laminacao

    Gorni, Antonio Augusto; Cavalcanti, Celso Gomes; Reis, Jackson Soares de Souza; Silveira, Jose Herbert Dolabela da [Companhia Siderurgica Paulista (COSIPA), SP (Brazil)

    1997-12-31

    Normalized plates can be got directly from the rolling heat through the use of a normalizing rolling process. In such way, an additional step of the conventional process of production of normalized plates - the normalizing heat treatment - can be suppressed, reducing the manufacturing cost of the product and shortening its production time. This relatively new production route is being used in several steelworks all over the world for many years. This work describes the implementation trials of normalizing rolling at COSIPA`s plate mill, using an alternative process of controlled rolling called recrystallization controlled rolling. The results got with new technique were successful, as it was able to produce plates with properties very similar to the conventionally normalized material, attending the requirements of the DIN 17100 RR 52-3N standard. This is one of many standards that permit the use of this new route of normalized steel plate production. (author) 14 refs., 8 figs., 2 tabs.

  18. 40 CFR 426.30 - Applicability; description of the rolled glass manufacturing subcategory.

    2010-07-01

    ... rolled glass manufacturing subcategory. 426.30 Section 426.30 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Rolled Glass Manufacturing Subcategory § 426.30 Applicability; description of the rolled...

  19. Kalium kanalers rolle i inflammation i Colitis Ulcerosa

    Hansen, Lars Koch

    2011-01-01

    Gennemgang af T-cellers kalium kanaler og deres mulige rolle i Colitis Ulcerosa. Artiklen skrevet til Den danske Colitis-Crohn Forenings Medlemsblad.......Gennemgang af T-cellers kalium kanaler og deres mulige rolle i Colitis Ulcerosa. Artiklen skrevet til Den danske Colitis-Crohn Forenings Medlemsblad....

  20. Modeling of Heat Transfer and Solidification of Composite Roll

    2001-01-01

    Modeling of heat transfer and solidification of composite roll was established and used to predict the thermal history and solidification process of roll during spray forming. Evolution of temperature field of the preform and cooling rate in the growing deposit during spray deposition and post-deposition were numerically simulated.

  1. Measurements of Normal and Friction Forces in a Rolling Process

    Henningsen, Poul; Arentoft, Mogens; Wanheim, Tarras

    2004-01-01

    To improve the quality of frictional data and to validate the simulations in rolling, a load transducer for measuring normal and friction stresses in the deformation zone has been developed. The transducer consists of a strain gauge equipped insert embedded in the surface of the roll. The length of...

  2. New surface layers with low rolling resistance tested in Denmark

    Pettinari, Matteo; Schmidt, Bjarne; Jensen, Bjarne Bo;

    2014-01-01

    The project ‘CO2 emission reduction by exploitation of rolling resistance modeling of pavements’ (COOEE) was started in 2011 to establish a scientific background for development of novel pavement types and asset management solutions that minimize the rolling resistance for cars and trucks, the...

  3. Key factors for warm rolled bond of 6111-aluminium strip

    2006-01-01

    Based on rolling tests and simulation, the bond behavior and its mechanism of 6111-aluminum alloy commonly used in auto industry were studied. As main factors, the effects of different heating stratagem, rolling speed and reduction on bond were tested. The effect of rolling speed on bond was produced by the synthetical result of contact time and temperature of rolling zone. Higher speed creates higher temperature of rolling zone but decreases contact time of interfaces, and bond strength decreases accordingly. The bond strength increases along with the increase of entry temperature before a turning point, after the turning point bond strength changes gently. Cold rolling is hard to get a satisfying bond result although the rolling parameters are adjusted, while warm bond reaches a higher strength that is comparable to the parent material. The analysis of surfaces separated by shear test shows that for warm bonding the rolling texture disappears on the bond area but the scratch track remain on the bond area for cold bond. There is no gap at the position of interface for well-bond sample. The results of this study are helpful to create well-bond materials for auto industry.

  4. Rock'n'Roll: The Sounds of Rebellion?

    L.J.M. d' Anjou (Leo)

    2000-01-01

    textabstractThe fifties were the scene of a 'virtual revolution' in popular music. Around 1954 rock'n'roll surfaced and took America by surprise; the young were excited and the adults shocked. The paper deals with two questions. First, how could rock'n'roll develop into an autonomous popular music

  5. Structure Irregularity Impedes Drop Roll-Off at Superhydrophobic Surfaces

    Larsen, Simon Tylsgaard; Andersen, Nis Korsgaard; Søgaard, Emil; Taboryski, Rafael J.

    2014-01-01

    We study water drop roll-off at superhydrophobic surfaces with different surface patterns. Superhydrophobic microcavity surfaces were fabricated in silicon and coated with 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS). For the more irregular surface patterns, the observed increase in roll...

  6. Genetic Algorithm-Based Optimization Used in Rolling Schedule

    YANG Jing-ming; CHE Hai-jun; DOU Fu-ping; ZHOU Tao

    2008-01-01

    A genetic algorithm-based optimization was used for 1 370 mm tandem cold rolling schedule, in which the press rates were coded and operated. The superiority individual is reserved in every generation. Analysis and comparison of optimized schedule with the existing schedule were offered. It is seen that the performance of the optimal rolling schedule is satisfactory and promising.

  7. Politics Revisited: Metatextual Implications of Rock and Roll Criticism.

    McDonald, James R.

    1988-01-01

    By viewing rock lyrics as a vehicle that demands a sociopolitical response, rock and roll critics place in the hands of rock artists a responsibility that is not warranted. Particularly with regard to political messages, rock and roll should be viewed from a more individualized perspective. (BJV)

  8. Technical evaluation of TomoTherapy automatic roll correction.

    Laub, Steve; Snyder, Michael; Burmeister, Jay

    2015-01-01

    The TomoTherapy Hi·Art System allows the application of rotational corrections as a part of the pretreatment image guidance process. This study outlines a custom method to perform an end-to-end evaluation of the TomoTherapy Hi·Art roll correction feature. A roll-sensitive plan was designed and delivered to a cylindrical solid water phantom to test the accuracy of roll corrections, as well as the ability of the automatic registration feature to detect induced roll. Cylindrical target structures containing coaxial inner avoidance structures were placed adjacent to the plane bisecting the phantom and 7 cm laterally off central axis. The phantom was positioned at isocenter with the target-plane parallel to the couch surface. Varying degrees of phantom roll were induced and dose to the targets and inner avoidance structures was measured using Kodak EDR2 films placed in the target-plane. Normalized point doses were compared with baseline (no roll) data to determine the sensitivity of the test and the effectiveness of the roll correction feature. Gamma analysis comparing baseline, roll-corrected, and uncorrected films was performed using film analysis software. MVCT images were acquired prior to plan delivery. Measured roll was compared with induced roll to evaluate the automatic registration feature's ability to detect rotational misalignment. Rotations beyond 0.3° result in statistically significant deviation from baseline point measurements. Gamma pass rates begin to drop below 90% at approximately 0.5° induced rotation at 3%/3 mm and between 0.2° and 0.3° for 2%/2 mm. With roll correction applied, point dose measurements for all rotations are indistinguishable from baseline, and gamma pass rates exceed 96% when using 3% and 3 mm as evaluation criteria. Measured roll via the automatic registration algorithm agrees with induced rotation to within the test sensitivity for nearly all imaging settings. The TomoTherapy automatic registration system accurately detects

  9. High-speed deformation of aluminum by cold rolling

    High-speed deformation of aluminum was carried out by use of a high-speed rolling machine, and the results were compared with those of impact compression. The rolled specimens were electro-polished and observed under an electron microscope. As compared with the microstructures observed in the impact compression specimens, the microstructures observed in the rolled specimens showed almost the same tendency as impact compression for vacancy loop formation, but a different tendency for dislocation cell formations. The difference in the results is explained by the variation in strain rate during deformation in rolling. The results indicate that in high-speed rolling, vacancies and dislocations are produced independently during different periods. Specifically, in the high-strain period, during which dislocations are not generated, deformation proceeds without dislocations

  10. Roll waves in two-layer Hele-Shaw flows

    Stepanova, I. V.; Chesnokov, A. A.; Liapidevskii, V. Yu

    2016-06-01

    In this paper we study the emergence and development of roll waves in two-layer fluid flow in a Hele-Shaw cell. We propose the mathematical model of such flow and define the conditions of transition from stable state to instability in the form of the roll waves. We find out the physical parameters of flows at which the roll waves exist. A linear stability analysis and the Whitham criterion of roll waves existence are used for solving the problem and arrive to identical conclusions on depths of upper and lower layers at which violation of flow stability occurs. The numerical calculations for the obtained mathematical model at found ratios of densities, viscosities and depths of layers are performed. They confirm development of the roll waves of finite amplitude from small oscillations of the interface.

  11. Seismic performance of isolation system of rolling friction with springs

    魏标; 戴公连; 文颖; 夏烨

    2014-01-01

    In order to study an isolation system of rolling friction with springs, computer programs were compiled to evaluate the seismic performance based on its movement characteristics. Through the programs, the influences of various seismic performance factors, e.g., rolling friction coefficient, spring constant, were systematically investigated. Results show that by increasing the rolling friction coefficient, the structural relative displacement due to seismic load effectively decreases, while the structural response magnitude varies mainly depending on the correlations between the following factors:the spring constant, the earthquake intensity, and the rolling friction coefficient. Furthermore, increasing the spring constant can decrease the structural relative displacement, as well as residual displacement, however, it increases the structural response magnitude. Finally, based on the analyses of various seismic performance factors subjected to the scenario earthquakes, optimized theoretical seismic performance can be achieved by reasonably combining the spring constant and the rolling friction coefficient.

  12. Calendering and Rolling of Viscoplastic Materials: Theory and Experiments

    Mitsoulis, E.; Sofou, S.; Muliawan, E. B.; Hatzikiriakos, S. G.

    2007-04-01

    The calendering and rolling processes are used in a wide variety of industries for the production of rolled sheets or films of specific thickness and final appearance. The acquired final sheet thickness depends mainly on the rheological properties of the material. Materials which have been used in the present study are foodstuff (such as mozzarella cheese and flour-water dough) used in food processing. These materials are rheologically viscoplastic, obeying the Herschel-Bulkley model. The results give the final sheet thickness and the torque as a function of the roll speed. Theoretical analysis based on the Lubrication Approximation Theory (LAT) shows that LAT is a good predictive tool for calendering, where the sheet thickness is very small compared with the roll size. However, in rolling where this is not true, LAT does not hold, and a 2-D analysis is necessary.

  13. Development of rolling texture in copper and brass

    Leffers, Torben; Grum-Jensen, A.

    1968-01-01

    The development of texture in copper and brass (15 pct Zn by weight) rolled at room temperature and in copper rolled at -196degC has been followed by determination of pole figures for various degrees of reduction. The concurrent development in microstructure has been investigated by transmission...... electron microscopy. For low deformations, the texture in brass, and in copper rolled at -196degC, is the same as the texture in copper rolled at room temperature. The difference in texture does not show until 50% reduction. At the same reduction at which the difference in texture appears, mechanical...... twinning starts in brass and low-temperature rolled copper. Nevertheless, Wassermann's twinning theory is found to be incompatible with the present results....

  14. Chaotic travelling rolls in Rayleigh–Bénard convection

    Supriyo Paul; Krishna Kumar; Mahendra K Verma; Daniele Carati; Arnab K De; Vinayak Eswaran

    2010-01-01

    In this paper we investigate two-dimensional (2D) Rayleigh–B ́enard convection using direct numerical simulation in Boussinesq fluids with Prandtl number = 6.8 confined between thermally conducting plates. We show through the simulation that in a small range of reduced Rayleigh number (770 < < 890) the 2D rolls move chaotically in a direction normal to the roll axis. The lateral shift of the rolls may lead to a global flow reversal of the convective motion. The chaotic travelling rolls are observed in simulations with free-slip as well as no-slip boundary conditions on the velocity field. We show that the travelling rolls and the flow reversal are due to an interplay between the real and imaginary parts of the critical modes.

  15. Fatigue crack growth and fracture mechanics analysis of a working roll surface layer material

    M. Drobne

    2014-10-01

    Full Text Available Fatigue crack growth and fracture mechanics analysis of a working roll surface layer material is presented in this paper. The research is done on a hot strip mill working roll where High Chromium Steel is used for roll’s shell material. To obtain corresponding parameters, a rectangular single edge notched bend specimens – SENB, according to standard BS 7448, were used. The fatigue crack growth analysis was done on a resonant testing machine with use of special crack gauges, while for fracture mechanics parameters the electro–mechanical testing machine was used.

  16. Influence of chemistry and hot rolling conditions on high permeability non-grain oriented silicon steel

    This paper discusses the influence of chemical composition on the final electromagnetic properties in higher permeability material. Furthermore, the effect of the hot rolling practice and the end of austenite transformation temperature range on the hot band microstructure is described. The magnetic polarization J 5000 better than 1.7 T, using hot rolling conditions 40 mm transfer bar thickness, finish mill entry temperature 1000 deg. C, and finishing temperature 800-840 deg. C and after decarburization heat treatment and grain growth treatment, was obtained

  17. Effect of Rolling Massage on the Vortex Flow in Blood Vessels with Lattice Boltzmann Simulation

    Yi, Hou Hui

    The rolling massage manipulation is a classic Chinese Medical Massage, which is a nature therapy in eliminating many diseases. Here, the effect of the rolling massage on the cavity flows in blood vessel under the rolling manipulation is studied by the lattice Boltzmann simulation. The simulation results show that the vortex flows are fully disturbed by the rolling massage. The flow behavior depends on the rolling velocity and the rolling depth. Rolling massage has a better effect on the flows in the cavity than that of the flows in a planar blood vessel. The result is helpful to understand the mechanism of the massage and develop the rolling techniques.

  18. Truck Roll Stability Data Collection and Analysis

    Stevens, SS

    2001-07-02

    The principal objective of this project was to collect and analyze vehicle and highway data that are relevant to the problem of truck rollover crashes, and in particular to the subset of rollover crashes that are caused by the driver error of entering a curve at a speed too great to allow safe completion of the turn. The data are of two sorts--vehicle dynamic performance data, and highway geometry data as revealed by vehicle behavior in normal driving. Vehicle dynamic performance data are relevant because the roll stability of a tractor trailer depends both on inherent physical characteristics of the vehicle and on the weight and distribution of the particular cargo that is being carried. Highway geometric data are relevant because the set of crashes of primary interest to this study are caused by lateral acceleration demand in a curve that exceeds the instantaneous roll stability of the vehicle. An analysis of data quality requires an evaluation of the equipment used to collect the data because the reliability and accuracy of both the equipment and the data could profoundly affect the safety of the driver and other highway users. Therefore, a concomitant objective was an evaluation of the performance of the set of data-collection equipment on the truck and trailer. The objective concerning evaluation of the equipment was accomplished, but the results were not entirely positive. Significant engineering apparently remains to be done before a reliable system can be fielded. Problems were identified with the trailer to tractor fiber optic connector used for this test. In an over-the-road environment, the communication between the trailer instrumentation and the tractor must be dependable. In addition, the computer in the truck must be able to withstand the rigors of the road. The major objective--data collection and analysis--was also accomplished. Using data collected by instruments on the truck, a ''bad-curve'' database can be generated. Using

  19. All polymer photovoltaics: From small inverted devices to large roll-to-roll coated and printed solar cells

    Liu, Yao; Larsen-Olsen, Thue Trofod; Zhao, Xingang; Andreasen, Birgitta; Søndergaard, Roar R.; Helgesen, Martin; Norrman, Kion; Jørgensen, Mikkel; Krebs, Frederik C; Zhan, Xiaowei

    2013-01-01

    Inverted all polymer solar cells based on a blend of a perylene diimide based polymer acceptor and a dithienosilole based polymer donor were fabricated from small area devices to roll-to-roll (R2R) coated and printed large area modules. The device performance was successfully optimized by using...

  20. A round robin study of flexible large-area roll-to-roll processed polymer solar cell modules

    Krebs, Frederik C; Gevorgyan, Suren; Gholamkhass, Bobak;

    2009-01-01

    A round robin for the performance of roll-to-roll coated flexible large-area polymer solar-cell modules involving 18 different laboratories in Northern America, Europe and Middle East is presented. The study involved the performance measurement of the devices at one location (Risø DTU) followed b...

  1. Roll-to-Roll Slot–Die Coated Organic Photovoltaic (OPV) Modules with High Geometrical Fill Factors

    Galagan, Y.; Fledderus, H.; Gorter, H.; Mannetje, H.H. 't; Shanmugam, S.; Mandamparambil, R.; Bosman, J.; Rubingh, J.M.; Teunissen, J.P.; Salem, A.; Vries, I.G. de; Andriessen, R.; Groen, W.A.

    2015-01-01

    Flexible semi-transparent organic photovoltaic (OPV) modules were manufactured by roll-to-roll slot–die coating of three functional layers [ZnO, photoactive layer, and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)] and either the screen printing or inkjet printing of the top ele

  2. Interlaboratory outdoor stability studies of flexible roll-to-roll coated organic photovoltaic modules: Stability over 10,000 h

    Gevorgyan, Suren; Madsen, Morten Vesterager; Dam, Henrik Friis;

    2013-01-01

    This work attempts to reveal the comparability issues related to outdoor testing procedures of organic photovoltaic (OPV) modules via studies of inter-laboratory long-term outdoor measurements of roll-to-roll coated flexible OPV modules (P3HT:PCBM, inverted architecture) in different geographic...

  3. Flexible organic tandem solar modules with 6% efficiency: combining roll-to-roll compatible processing with high geometric fill factors

    Spyropoulos, G. D.; Kubis, P.; Li, Na;

    2014-01-01

    Organic solar cell technology bears the potential for high photovoltaic performance combined with truly low-cost, high-volume processing. Here we demonstrate organic tandem solar modules on flexible substrates fabricated by fully roll-to-roll compatible processing at temperatures...

  4. 75 FR 65453 - Certain Hot-Rolled Flat-Rolled Carbon Quality Steel Flat Products From Brazil: Notice of...

    2010-10-25

    ...)) steels, high strength low alloy (HSLA) steels, and the substrate for motor lamination steels. IF steels... niobium added to stabilize carbon and nitrogen elements. HSLA steels are recognized as steels with micro...-Rolled Flat-Rolled Carbon Quality Steel Products From Brazil, 64 FR 38756, 38759 (July 19, 1999). On...

  5. Roll-to-Roll Printed Silver Nanowire Semitransparent Electrodes for Fully Ambient Solution-Processed Tandem Polymer Solar Cells

    Angmo, Dechan; Andersen, Thomas Rieks; Bentzen, Janet Jonna;

    2015-01-01

    Silver nanowires (AgNWs) and zinc oxide (ZnO) are deposited on flexible substrates using fast roll-to-roll (R2R) processing. The AgNW film on polyethylene terephthalate (PET) shows >80% uniform optical transmission in the range of 550-900 nm. This electrode is compared to the previously reported ...

  6. Cotton-textile-enabled flexible self-sustaining power packs via roll-to-roll fabrication

    Gao, Zan; Bumgardner, Clifton; Song, Ningning; Zhang, Yunya; Li, Jingjing; Li, Xiaodong

    2016-05-01

    With rising energy concerns, efficient energy conversion and storage devices are required to provide a sustainable, green energy supply. Solar cells hold promise as energy conversion devices due to their utilization of readily accessible solar energy; however, the output of solar cells can be non-continuous and unstable. Therefore, it is necessary to combine solar cells with compatible energy storage devices to realize a stable power supply. To this end, supercapacitors, highly efficient energy storage devices, can be integrated with solar cells to mitigate the power fluctuations. Here, we report on the development of a solar cell-supercapacitor hybrid device as a solution to this energy requirement. A high-performance, cotton-textile-enabled asymmetric supercapacitor is integrated with a flexible solar cell via a scalable roll-to-roll manufacturing approach to fabricate a self-sustaining power pack, demonstrating its potential to continuously power future electronic devices.

  7. Roll-to-roll coated PBI membranes for high temperature PEM fuel cells

    Steenberg, Thomas; Hjuler, Hans Aage; Terkelsen, Carina;

    2012-01-01

    characterization with respect to solubility, phosphoric acid doping and fuel cell performance. Our results showed that the PBI membranes prepared in this work have identical properties compared to traditionally cast membranes while enabling an increase of a factor of 100 in manufacturing speed.......We employed roll-to-roll coating in the preparation of 40 μm thick poly[2,2′(m-phenylene)-5,5′bibenzimidazole] (PBI) films for fuel cells using both knife-coating (KC) and slot-die (SD) coating. The films were coated directly from a 9% (w/w) solution of PBI in dimethylacetamide onto a sacrificial...... avoid skinning. Films were prepared by a single coating step and by two subsequent coating steps in order to explore whether two coating steps gave films with fewer defects. A significant development towards upscaling the PEM fuel cell technology was that the PBI membrane was coated onto a sacrificial...

  8. Large-scale roll-to-roll photonic sintering of flexo printed silver nanoparticle electrodes

    Hösel, Markus; Krebs, Frederik C

    2012-01-01

    In this report we employ static and roll-to-roll (R2R) photonic sintering processes on flexo printed silver nanoparticle-based electrode structures with a heat-sensitive 60 mm thin barrier foil as a substrate. We use large area electrode structures to visualize the increased optical footprint of...... energies above the threshold level have only minor impact on the conductivity but lead to cracks and substrate deformation. A second silver nanoparticle ink was printed, which was already optimized for lowtemperature drying. Here we show that photonic sintering has only a minor impact on the conductivity...... single and quadruple flashes, and the R2R challenges in the form of overlapping exposures. It is shown that single flash exposure is enough to significantly increase the conductivity and adhesion without damaging the foil or build-up of cracks in the silver layer. Additional flash exposures or increased...

  9. Using Light-Induced Thermocleavage in a Roll-to-Roll Process for Polymer Solar Cells

    Krebs, Frederik C; Norrman, Kion

    2010-01-01

    We report on the use of intense visible light with a narrow spectral distribution matched to the region where the conjugated polymer material absorbs to selectively heat the active material and induce thermocleavage. We show a full roll-to-roll process, leading to complete large-area polymer sola...... ion mass spectrometry, attenuated total reflectance infrared, and transmission/reflection UV−vis techniques....... cell modules using light-induced thermocleavage. The process employs full solution processing in air for all five layers in the device and does not employ indium−tin oxide or vacuum processing. The process steps were carefully analyzed using X-ray photoelectron spectroscopy, time-of-flight secondary...

  10. Thermoresistive Strain Sensor and Positioning Method for Roll-to-Roll Processes

    Kuan-Hsun Liao

    2014-05-01

    Full Text Available This study uses the Joule heating effect-generated temperature difference to monitor in real-time and localize both compressive and tensile strains for the polymer substrates used in the roll-to-roll process. A serpentine gold (Au line was patterned on a polyethylenenaphthalate (PEN substrate to form the strain sensor based on thermoresistive behavior. This strain sensor was then subjected to either current or voltage to induce the Joule heating effect on the Au resistor. An infrared (IR detector was used to monitor the strain-induced temperature difference on the Au and PEN surfaces and the minimal detectable bending radius was 0.9 mm with a gauge factor (GF of 1.46. The proposed design eliminates the judgment ambiguity from conventional resistive strain sensors where resistance is the only physical quantity monitored. This study precisely and successfully indicated the local strain quantitatively and qualitatively with complete simulations and measurements.

  11. Material for hot rolling of high boron content austenite stainless steel, and hot rolling method

    A hot rolling material made of a high boron content austenite stainless steel of the present invention comprises a slab made of an austenite stainless steel containing from 0.6 to 2.0% by weight of B and a pad-welded metal layer formed on the side surface of the slab. The pad-welded metal layer has δ ferrite amount of from 3 to 12% by volume, B content up to 0.3% by weight, a thickness of 3mm or greater, and is subjected to hot rolling after heated to a temperature of from 1100 to 1200degC. This can prevent occurrence of peripheral cracking and the material can be industrially manufactured stably at a low cost. (T.M.)

  12. Cotton-textile-enabled flexible self-sustaining power packs via roll-to-roll fabrication

    Gao, Zan; Bumgardner, Clifton; Song, Ningning; Zhang, Yunya; Li, Jingjing; Li, Xiaodong

    2016-01-01

    With rising energy concerns, efficient energy conversion and storage devices are required to provide a sustainable, green energy supply. Solar cells hold promise as energy conversion devices due to their utilization of readily accessible solar energy; however, the output of solar cells can be non-continuous and unstable. Therefore, it is necessary to combine solar cells with compatible energy storage devices to realize a stable power supply. To this end, supercapacitors, highly efficient energy storage devices, can be integrated with solar cells to mitigate the power fluctuations. Here, we report on the development of a solar cell-supercapacitor hybrid device as a solution to this energy requirement. A high-performance, cotton-textile-enabled asymmetric supercapacitor is integrated with a flexible solar cell via a scalable roll-to-roll manufacturing approach to fabricate a self-sustaining power pack, demonstrating its potential to continuously power future electronic devices. PMID:27189776

  13. Roll-to-roll printed resistive WORM memory on a flexible substrate

    The fabrication process and the operation characteristics of a fully roll-to-roll printed resistive write-once-read-many memory on a flexible substrate are presented. The low-voltage (<10 V) write operation of the memories from a high resistivity ‘0’ state to a low resistivity ‘1’ state is based on the rapid electrical sintering of bits containing silver nanoparticles. The bit ink is formulated by mixing two commercially available silver nanoparticle inks in order to tune the initial square resistance of the bits and to create a self-organized network of percolating paths. The electrical performance of the memories, including read and write characteristics, is described and the long-term stability of the less stable ‘0’ state is studied in different environmental conditions. The memories can find use in low-cost mass printing applications. (paper)

  14. Roll-to-roll printed resistive WORM memory on a flexible substrate.

    Leppäniemi, Jaakko; Mattila, Tomi; Kololuoma, Terho; Suhonen, Mika; Alastalo, Ari

    2012-08-01

    The fabrication process and the operation characteristics of a fully roll-to-roll printed resistive write-once-read-many memory on a flexible substrate are presented. The low-voltage (resistivity '0' state to a low resistivity '1' state is based on the rapid electrical sintering of bits containing silver nanoparticles. The bit ink is formulated by mixing two commercially available silver nanoparticle inks in order to tune the initial square resistance of the bits and to create a self-organized network of percolating paths. The electrical performance of the memories, including read and write characteristics, is described and the long-term stability of the less stable '0' state is studied in different environmental conditions. The memories can find use in low-cost mass printing applications. PMID:22782128

  15. Noncontact conductivity and dielectric measurement for high throughput roll-to-roll nanomanufacturing

    Orloff, Nathan D.; Long, Christian J.; Obrzut, Jan; Maillaud, Laurent; Mirri, Francesca; Kole, Thomas P.; McMichael, Robert D.; Pasquali, Matteo; Stranick, Stephan J.; Alexander Liddle, J.

    2015-11-01

    Advances in roll-to-roll processing of graphene and carbon nanotubes have at last led to the continuous production of high-quality coatings and filaments, ushering in a wave of applications for flexible and wearable electronics, woven fabrics, and wires. These applications often require specific electrical properties, and hence precise control over material micro- and nanostructure. While such control can be achieved, in principle, by closed-loop processing methods, there are relatively few noncontact and nondestructive options for quantifying the electrical properties of materials on a moving web at the speed required in modern nanomanufacturing. Here, we demonstrate a noncontact microwave method for measuring the dielectric constant and conductivity (or geometry for samples of known dielectric properties) of materials in a millisecond. Such measurement times are compatible with current and future industrial needs, enabling real-time materials characterization and in-line control of processing variables without disrupting production.

  16. Effect of pass schedule and groove design on the metal deformation of 38MnVS6 in the initial passes of hot rolling

    R S Nalawade; V R Marje; G Balachandran; V Balasubramanian

    2016-01-01

    The deformation behaviour of a hot rolled micro-alloyed steel bar of grade 38MnVS6 was examined using an FEM model during the initial passes in a blooming mill, as a function of three different pass schedules,roll groove depth, collar taper angle and corner radius. The simulations predicted the effective strain penetration,load, torque, fish tail billet end shapes, and metal flow behaviour at a chosen temperature, mill rpm and draft. The model predictions were validated for typical groove geometry and a typical pass schedule. Lower collar taper angle, lower corner radius and higher depth of groove in hot rolling enabled achievement of higher strain penetration, higher mill load and lower fish tail formation. The present study establishes the capability of the model to improve the internal quality of the rolled billet as measured by effective strain which was corroborated to the rolled bar macrostructure and microstructure. The model enables yield improvement by the choice of draft to minimise fish tail losses. The surface quality is improved by the ability to avoid fin formation that occurs at certain conditions of rolling. Thus, the groove geometry, roll pass schedule and rolling mill parameters and temperature can be optimised for best product quality and yield.

  17. Research on automatic loading & unloading technology for vertical hot ring rolling process

    Xiaokai Wang

    2015-01-01

    Full Text Available The automatic loading & unloading technology is the key to the automatic ring production line. In this paper, the automatic vertical hot ring rolling (VHRR process is taken as the target, the method of the loading & unloading for VHRR is proposed, and the mechanical structure of loading & unloading system is designed, The virtual prototype model of VHRR mill and loading & unloading mechanism is established, and the coordinated control method of VHRR mill and loading & unloading auxiliaries is studied, the movement trace and dynamic characteristic of the critical components are obtained. Finally, a series of hot ring rolling tests are conducted on the VHRR mill, and the production rhythm and the formed rings' geometric precision are analysed. The tests results show that the loading & unloading technology can meet the high quality and high efficiency ring production requirement. The research conclusions have practical significance for the large-scale automatic ring production.

  18. Thick backed carbon targets via mechanical rolling

    For targets requiring thick backing foils, the straight-forward and usual method is to deposit the target material directly on the backing by thermal evaporation. In some instances the reverse is more desirable, adding a backing to an already existing target foil, for example. A recent study involving measurement of the lifetime of the first 2+ excited state in 36Ar by the Doppler shift attenuation method required 0.5 mg/cm2 natural carbon targets on thick (18 mg/cm2) gold and lead backings. Problems of delamination had arisen after beam irradiation using thick gold backings for these experiments. Carbon target foils were then prepared by mechanical rolling in direct contact with a thick lead backing using an intermediate layer of indium to assure good adhesion of the layers. Details of the method will be discussed. (author)

  19. Periodically fighting shake, rattle and roll

    Brun, M; Jones, I S

    2011-01-01

    How easy is it to suppress shake, rattle and roll in a long bridge or a skyscraper? Most practical structures are designed so that long wave resonance vibrations can be avoided. However, there are recent examples, such as the Millennium Bridge in London or the Volga Bridge in Volgograd, which show that unexpected external forces may result in large scale unwanted shake and rattle. Full scale alteration of a bridge (or a skyscraper) would not be considered as an acceptable option, unless the structure has collapsed. Can we fix this by examining a representative part of the structure only and making small lightweight changes? We will do it here and illustrate an idea linking the engineering analysis to elastic waveguides.

  20. Synthesis and Characterization of Hot-Roll and Cold-Roll Byproduct-Derived Strontium Hard Ferrites

    H. S. Woon

    2009-01-01

    Full Text Available Problem statement: Ceramic permanent magnets or more commonly known as strontium hexagonal ferrites have been widely used in permanent magnetic materials as they provide high remanence, high coercivity, relatively high energy product and good chemical stability. In this study, we treated factory byproduct from hot-roll and cold-roll steel industry was used as raw material in synthesis of strontium hexagonal hard ferrites. Approach: X-Ray Diffraction (XRD was employed to confirm the formation of strontium hard ferrite compound. Vibrating Sample Magnetometer (VSM was used to analyze the magnetic properties of samples prepared. Results: The magnetic properties, namely remanence and coercivity of factory byproduct-derived strontium hard ferrites were compared. The cold-roll-derived strontium hard ferrite showed higher remanence in this study. Conclusion: This implied that cold-roll byproduct was a better candidate to replace hematite in preparation of strontium hard ferrites compared to hot-roll byproduct.

  1. Numerical Treatments of Slipping/No-Slip Zones in Cold Rolling of Thin Sheets with Heavy Roll Deformation

    Yukio Shigaki

    2015-04-01

    Full Text Available In the thin sheet cold rolling manufacturing process, a major issue is roll elastic deformation and its impact on roll load, torque and contact stresses. As in many systems implying mechanical contact under high loading, a central part is under “sticking friction” (no slip while both extremities do slip to accommodate the material acceleration of the rolled metal sheet. This is a crucial point for modeling of such rolling processes and the numerical treatment of contact and friction (“regularized” or not, of the transition between these zones, does have an impact on the results. Two ways to deal with it are compared (regularization of the stick/slip transition, direct imposition of a no-slip condition and recommendations are given.

  2. Rocking and rolling: a can that appears to rock might actually roll.

    Srinivasan, Manoj; Ruina, Andy

    2008-12-01

    A beer bottle or soda can on a table, when slightly tipped and released, falls to an upright position and then rocks up to a somewhat opposite tilt. Superficially this rocking motion involves a collision when the flat circular base of the container slaps the table before rocking up to the opposite tilt. A keen eye notices that the after-slap rising tilt is not generally just diametrically opposite the initial tilt but is veered to one side or the other. Cushman and Duistermaat [Regular Chaotic Dyn. 11, 31 (2006)] recently noticed such veering when a flat disk with rolling boundary conditions is dropped nearly flat. Here, we generalize these rolling disk results to arbitrary axi-symmetric bodies and to frictionless sliding. More specifically, we study motions that almost but do not quite involve a face-down collision of the round container's bottom with the tabletop. These motions involve a sudden rapid motion of the contact point around the circular base. Surprisingly, similar to the rolling disk, the net angle of motion of this contact point is nearly independent of initial conditions. This angle of turn depends simply on the geometry and mass distribution but not on the moment of inertia about the symmetry axis. We derive simple asymptotic formulas for this "angle of turn" of the contact point and check the result with numerics and with simple experiments. For tall containers (height much bigger than radius) the angle of turn is just over pi and the sudden rolling motion superficially appears as a nearly symmetric collision leading to leaning on an almost diametrically opposite point on the bottom rim. PMID:19256970

  3. Advanced cold rolled steels for automotive applications

    Hofmann, H. [ThyssenKrupp Steel AG, Eberhardstrasse 12, 44145 Dortmund (Germany); Mattissen, D.; Schaumann, T.W. [ThyssenKrupp Steel AG, Duisburg (Germany)

    2006-09-15

    Advanced multiphase steels offer a great potential for bodies-in-white through their combination of formability and achievable component strength levels. They are first choice for strength and crash-relevant parts of challenging geometry. The intensive development of high-strength multiphase steels by ThyssenKrupp has led to hot dip galvanizing concepts with an outstanding forming potential. Hot rolled, hot dip galvanized complex phase steels are currently produced in addition to cold rolled DP and RA steels. New continuously annealed grades with tensile strength levels of up to 1000 MPa in combination with sufficient ductility for applications mainly in the field of structural automobile elements make use of the classic advantages of microalloying as well as the principles of DP and TRIP steels. Further improvement of properties will be reached by the new class of high manganese alloyed steels. (Abstract Copyright [2006], Wiley Periodicals, Inc.) [German] Fortschrittliche Multiphasen-Staehle eroeffnen wegen der inzwischen erreichbaren Kombination aus Umformbarkeit und Bauteilfestigkeit ein enormes Potenzial fuer Rohkarosserien. Sie stellen eine erste Wahl dar, wenn es um Festigkeit und um Crashsicherheit geht und besondere Anforderungen an die Bauteilgeometrien gestellt werden. Bei ThyssenKrupp hat die Entwicklung hochfester Multiphasen-Staehle in Verbindung mit dem Feuerverzinken zur Realisierung von Blechhalbzeugen gefuehrt, die hervorragend formbar sind. Es werden heute feuerverzinkte Komplexphasenstaehle neben den bewaehrten kaltgewalzten Dualphasen(DP) - und Retained Austenit(RA)-Staehlen produziert. Die neuen kontinuierlich gegluehten Stahlvarianten mit Festigkeiten bis zu 1000 MPa in Kombination mit der bei Strukturbauteilen im Automobilbau geforderten Duktilitaet nutzen sowohl die klassischen Vorteile des Mikrolegierens aus und dazu die Prinzipien, die man bei DP- und TRIP-Staehlen anwendet. Eine weitere Verbesserung des Eigenschaftsprofils wird mit dem

  4. Nanoscale precipitation in hot rolled sheet steel

    Sun, Jun

    Some newer hot rolled high strength low alloy (HSLA) steels with a single phase ferrite matrix have obtained substantial strengthening from nanoscale precipitation. These HSLA are reported to have a good combination of strength, ductility and hole-expansion ability. In the current work, Gleeble ® 3500 torsion testing was employed to simulate the hot rolling process with varying run-out table cooling rates and coiling temperatures on five microalloyed steels with additions of Ti, Nb, Mo, Cr and V, to investigate the effects of microalloy additions and processing conditions on microstructures as well as mechanical properties. Subsized tensile specimens obtained from as-twisted torsion samples were used to evaluate mechanical properties. The precipitation states of the five steels with different processing conditions were characterized using extraction replica TEM. Comparison of microstructures and mechanical properties was discussed. Characterization of the microstructure via light optical microscopy showed the matrix microstructure was mainly influenced by coiling temperature, which indicates that the transformation from austenite to ferrite occurred during the coiling period. A higher Ti content was shown to reduce the second constituent fractions. Investigation of carbon extraction replica specimens via TEM revealed the presence of nanoscale precipitation. Extensive nanoscale precipitation was observed in most of the specimens having a polygonal ferrite matrix, while in the granular bainite/ferrite microstructure at lower temperatures, fewer microalloy carbides were present. The specimens with polygonal ferrite had similar or higher yield strength than the specimens with granular bainite microstructure, which suggests the effectiveness of precipitation strengthening from extensive nanoscale precipitates. In the Nb-Mo steel, more significant strengthening due to grain refinement was evident. Yield strength values were less than reported for JFE's "NANOHITEN

  5. Application of Crown-Flatness Vector Analysis in Plate Rolling Schedule

    HU Xian-lei; WANG Zhao-dong; JIAO Zhi-jie; ZHAO Zhong; LIU Xiang-hua; WANG Guo-dong

    2004-01-01

    A simple plate crown model was introduced, and the crown-flatness vector analysis method was analyzed. Based on the plate rolling technology, the rolling schedule design of elongation phase is divided into three steps. First step is to calculate the reductions of first pass of elongation making full use of the mill capability to decrease the total pass number. The second step is to calculate the pass reduction for the last three or four passes to control crown and flatness by crown-flatness vector analysis method. In the third step, the maximum rolling force limit and the total pass number are adjusted to make the plate gauge at exit equal to target gauge with satisfactory flatness. The on-line application shows that this method is effective.

  6. Microstructure changes of IF steels during hot strip rolling

    The hot deformation behavior of three interstitial free (IF) steels containing Ti and/or Nb under strip or plate rolling was investigated by means of multi-pass torsion tests. All the tests were carried out at a strain rate of 2 s-1. Three types of strip rolling schedules (they differed only with respect to the number and total strain of finishing passes) and one type of plate rolling were employed. Under strip rolling conditions the effects of total finishing pass strain and first finishing pass temperature was investigated. The plate rolling schedule was used in order to determine the three critical hot deformation temperature, i.e. Tnr, Ar3 and Arl. The results indicate that , under strip rolling conditions, static recrystallization is responsible for the high degree of inter pass softening in the early passes of rolling. During the final passes, dynamic recrystallization occurs to a degree that depends on the composition of the steel, the total finishing strain and the temperature. (author)

  7. Design, Analysis and Optimization of Anti-Roll Bar

    Pravin Bharane

    2014-09-01

    Full Text Available Vehicle anti-roll bar is part of an automobile suspension system which limits body roll angle. This U-shaped metal bar connects opposite wheels together through short lever arms and is clamped to the vehicle chassis with rubber bushes. Its function is to reduce body roll while cornering, also while travelling on uneven road which enhances safety and comfort during driving. Design changes of anti-roll bars are quite common at various steps of vehicle production and a design analysis must be performed for each change. So Finite Element Analysis (FEA can be effectively used in design analysis of anti-roll bars. The finite element analysis is performed by ANSYS. This paper includes pre-processing, analysis, post processing, and analyzing the FEA results by using APDL (Ansys Parametric Design Language. The effects of anti-roll bar design parameters on final anti-roll bar properties are also evaluated by performing sample analyses with the FEA program developed in this project.

  8. Influence of rolling friction on single spout fluidized bed simulation

    Christoph Goniva; Christoph Kloss; Niels G. Deen; Johannes A. M. Kuipers; Stefan Pirker

    2012-01-01

    In this paper we study the effect of rolling friction on the dynamics in a single spout fluidized bed using Discrete Element Method (DEM) coupled to Computational Fluid Dynamics (CFD).In a first step we neglect rolling friction and show that the results delivered by the open source CFD-DEM framework applied in this study agree with previous simulations documented in literature.In a second step we include a rolling friction sub-model in order to investigate the effect of particle non-sphericity.The influence of particle-particle as well as particle-wall rolling friction on the flow in single spout fluidized bed is studied separately.Adequate rolling friction model parameters are obtained using first principle DEM simulations and data from literature.Finally,we demonstrate the importance of correct modelling of rolling friction for coupled CFD-DEM simulations of spout fluidized beds.We show that simulation results can be improved significantly when applying a rolling friction model,and that experimental data from literature obtained with Positron Emission Particle Tracking (PEPT) technique can be satisfactorily reproduced.

  9. Improved WKB analysis of slow-roll inflation

    We extend the WKB method for the computation of cosmological perturbations during inflation beyond leading order and provide the power spectra of scalar and tensor perturbations to second order in the slow-roll parameters. Our method does not require that the slow-roll parameters be constant. Although leading and next-to-leading results in the slow-roll parameters depend on the approximation technique used in the computation, we find that the inflationary theoretical predictions obtained may reach the accuracy required by planned observations. In two technical appendixes, we compare our technique and results with previous findings

  10. Study of Hydroplaning Risk on Rolling and Sliding Passenger Car

    Kumar, S S; Anupam, K.; Scarpas, A.; Kasbergen, C.

    2012-01-01

    Hydroplaning speed is known to vary over a range of tire slipping conditions from free rolling to completely skidding. An attempt has been made to simulate two extreme conditions of hydroplaning i.e. when the tire is completely rolling (0% slip) and a completely locked tire (100% slip). ASTM standard smooth tire moving over the plane pavement surface is considered in the model. The analyses showed that the hydroplaning risk associated with the locked tire is more than the rolling tire. The mo...

  11. Fast-roll solutions from two scalar field inflation

    Santos, J R L

    2015-01-01

    The cosmological equations of motion of scalar fields are commonly not easy to be analytically solved, which makes necessary to use approximation methods, as the {\\it slow-roll} regime. In such an approximation one considers the scalar field potentials to be nearly flat. On the other hand, the so called {\\it fast-roll} regime considers exactly flat potentials. Our purpose in this work is to obtain solutions for a two scalar field quintessence model in the fast-roll regime. Cosmological interpretations for such solutions are also presented.

  12. Correcting Quadrupole Roll in Magnetic Lenses with Skew Quadrupoles

    Walstrom, Peter Lowell [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2014-11-10

    Quadrupole rolls (i.e. rotation around the magnet axis) are known to be a significant source of image blurring in magnetic quadrupole lenses. These rolls may be caused by errors in mechanical mounting of quadrupoles, by uneven radiation-induced demagnetization of permanent-magnet quadrupoles, etc. Here a four-quadrupole ×10 lens with so-called ”Russian” or A -B B-A symmetry is used as a model problem. Existing SLAC 1/2 in. bore high-gradient quadrupoles are used in the design. The dominant quadrupole roll effect is changes in the first-order part of the transfer map (the R matrix) from the object to the image plane (Note effects on the R matrix can be of first order in rotation angle for some R-matrix elements and second order in rotation angle for other elements, as shown below). It is possible to correct roll-induced image blur by mechanically adjusting the roll angle of one or more of the quadrupoles. Usually, rotation of one quadrupole is sufficient to correct most of the combined effect of rolls in all four quadrupoles. There are drawbacks to this approach, however, since mechanical roll correction requires multiple entries into experimental area to make the adjustments, which are made according to their effect on images. An alternative is to use a single electromagnetic skew quadrupole corrector placed either between two of the quadrupoles or after the fourth quadrupole (so-called “non-local” correction). The basic feasibility of skew quadrupole correction of quadrupole roll effects is demonstrated here. Rolls of the third lens quadrupole of up to about 1 milliradian can be corrected with a 15 cm long skew quadrupole with a gradient of up to 1 T/m. Since the effect of rolls of the remaining three lens quadrupoles are lower, a weaker skew quadrupole can be used to correct them. Non-local correction of quadrupole roll effects by skew quadrupoles is shown to be about one-half as effective as local correction (i.e. rotating individual quadrupoles to zero

  13. Development of closed loop roll control for magnetic balance systems

    Covert, E. E.; Haldeman, C. W.; Ramohalli, G.; Way, P.

    1982-01-01

    This research was undertaken with the goal of demonstrating closed loop control of the roll degree of freedom on the NASA prototype magnetic suspension and balance system at the MIT Aerophysics Laboratory, thus, showing feasibility for a roll control system for any large magnetic balance system which might be built in the future. During the research under this grant, study was directed toward the several areas of torque generation, position sensing, model construction and control system design. These effects were then integrated to produce successful closed loop operation of the analogue roll control system. This experience indicated the desirability of microprocessor control for the angular degrees of freedom.

  14. Numerical simulation of involutes spline shaft in cold rolling forming

    王志奎; 张庆

    2008-01-01

    Design of forming dies and whole process of simulation of cold rolling involutes spline can be realized by using of CAD software of PRO-E and CAE software of DEFORM-3D. Software DEFORM-3D provides an automatic and optimized remeshing function, especially for the large deformation. In order to use this function sufficiently, simulation of cold rolling involutes spline can be implemented indirectly. The relationship between die and workpiece, forming force and characteristic of deformation in the forming process of cold rolling involutes spline are analyzed and researched. Meanwhile, reliable proofs for the design of dies and deforming equipment are provided.

  15. Formation of rolling and recrystallization textures in titanium and zirconium

    The results are presented of a study into the cold-rolling and recrystallization textures in iodide Ti and Zr subjected to 40-95% deformation. Pole figures for Ti and Zr after various deformations and after annealings at the temperatures of the beginning of crystallization are provided. It is shown that the cold-rolling texture forms less actively in zirconium than in titanium. After high deformations (over 80%) the rolling texture of zirconium becomes similar to that of titanium due to the similarity of their deformation mechanism. Texture strengthening in titanium and zirconium which is detected at the polygonization stage, more pronounced than in commercial titanium

  16. Rock-'n-roll: de sociale constructie van een muziekstijl

    Anjou, Leo

    2001-01-01

    textabstractThe rise of an autonomous youth culture is one of the most remarkable events of the fifties not in the least because of the noisy advent of its music: rock-'n-roll. This music shocked society and has been associated with rebellion and protest ever since. Rock-'n-roll acquired a meaning that went beyond music itself and the intentions of its producers because of its social construction. This article analyses the construction of rock-'n-roll, particularly the way it was shaped in th...

  17. Application of powder metallurgy and hot rolling processes for manufacturing aluminum/alumina composite strips

    In this study, aluminum matrix composites (AMC) with 2, 4, 6 and 10 wt% alumina were produced using powder metallurgy (PM), mechanical milling (MM) and vacuum hot pressing (VHP) techniques; then, this was followed by the hot-rolling process. During hot rolling, AMCs with 6 and 10 wt% Al2O3 were fractured whereas strip composites with 2 and 4 wt% Al2O3 were produced successfully. Microstructure and mechanical properties of the samples were investigated by optical and scanning electron microscopes and tensile and hardness tests, respectively. Microscopic evaluations of the hot-rolled composites showed a uniform distribution of alumina particles in the aluminum matrix. It was found that with increasing alumina content in the matrix, tensile strength (TS) and hardness increased and the percentage of elongation also decreased. Scanning electron microscope (SEM) was used to investigate aluminum/alumina interfaces and fracture surfaces of the hot rolled specimens after tensile test. SEM observations demonstrated that the failure mode in the hot-rolled Al-2 wt% Al2O3 composite strips is a typical ductile fracture, while the failure mode was shear ductile fracture with more flat surfaces in Al-4 wt% Al2O3 strips.

  18. NUMERICAL SIMULATION OF THE FIRST COLD ROLLING PASS OF A C-MN STRIP STEEL

    Willian Costa do Nascimento

    2013-03-01

    Full Text Available This work presents the modeling by the finite element method of the first cold rolling pass of a four-high mill at the CSN steel plant. For this purpose, a two dimensional model is proposed considering the work-roll as a rigid surface together with the assumptions of plane-strain state for the strip and material isotropy with nonlinear isotropic workhardening. A C-Mn steel strip with initial thickness of 3.5 mm was first characterized by means of uniaxial tensile tests in specimens cut along the rolling direction to evaluate the work-hardening parameters. In the finite element model, the contact is defined by means of the Coulomb’s law to describe the friction between the work-roll and the strip surfaces. Moreover, the industrial back and forward tensions are also taken into account as prescribed conditions in the finite element model. The numerical predictions of the rolling load show a good agreement with the measured data and the forecasted value is determined with the slab-method.

  19. Multilength Scale Patterning of Functional Layers by Roll-to-Roll Ultraviolet-Light-Assisted Nanoimprint Lithography.

    Leitgeb, Markus; Nees, Dieter; Ruttloff, Stephan; Palfinger, Ursula; Götz, Johannes; Liska, Robert; Belegratis, Maria R; Stadlober, Barbara

    2016-05-24

    Top-down fabrication of nanostructures with high throughput is still a challenge. We demonstrate the fast (>10 m/min) and continuous fabrication of multilength scale structures by roll-to-roll UV-nanoimprint lithography on a 250 mm wide web. The large-area nanopatterning is enabled by a multicomponent UV-curable resist system (JRcure) with viscous, mechanical, and surface properties that are tunable over a wide range to either allow for usage as polymer stamp material or as imprint resist. The adjustable elasticity and surface chemistry of the resist system enable multistep self-replication of structured resist layers. Decisive for defect-free UV-nanoimprinting in roll-to-roll is the minimization of the surface energies of stamp and resist, and the stepwise reduction of the stiffness from one layer to the next is essential for optimizing the reproduction fidelity especially for nanoscale features. Accordingly, we demonstrate the continuous replication of 3D nanostructures and the high-throughput fabrication of multilength scale resist structures resulting in flexible polyethylenetherephtalate film rolls with superhydrophobic properties. Moreover, a water-soluble UV-imprint resist (JRlift) is introduced that enables residue-free nanoimprinting in roll-to-roll. Thereby we could demonstrate high-throughput fabrication of metallic patterns with only 200 nm line width. PMID:27023664

  20. Effect of biomimetic coupling units' morphologies on rolling contact fatigue wear resistance of steel from machine tool rolling tracks

    Yang, Wanshi; Zhou, Hong; Sun, Liang; Wang, Chuanwei; Chen, Zhikai

    2014-04-01

    The rolling contact fatigue wear resistance plays an important role on ensuring machining precision of machine tool using rolling tracks. Bio-inspired wearable surfaces with the alternated hardness were prepared on the specimen of steel material from machine tool rolling tracks by biomimetic coupling laser remelting method to imitate biological coupling principle. The microstructures and micromorphologies of bionic units in different sizes were characterized by optical microscope. The specimens with bionic units in different sizes and distributions were tested for rolling contact fatigue wear resistance. Combining the finite element analysis and the results of wear tests, a discussion on rolling contact fatigue wear was had. The specimens with bionic units had better rolling contact fatigue wear resistance than the untreated one, while the specimens with bionic units in the alternative depth's distributions present a better rolling contact fatigue wear resistance than the ones with bionic units in the single depth's distribution. It attributed to the alternative distribution made further improvement on the dispersion of depth of stress concentration.

  1. Semi-industrial simulation of hot rolling and controlled cooling of Mn-Al TRIP steel sheets

    A. Grajcar

    2013-03-01

    Full Text Available Purpose: The aim of the work is a semi-industrial physical simulation of thermomechanical rolling and controlled cooling of advanced high-strength steels with increased Mn and Al content.Design/methodology/approach: Four steels of various Mn and Nb concentration were thermomechanically rolled in 3 and 5 passes using a modern LPS line for physical simulation of hot rolling at a semi-industrial scale. The hot deformation course is fully automated as well as controlled cooling applied directly after finishing rolling. Temperature-time and force-energetic parameters of hot rolling were continuously registered and assessed.Findings: The applied line consisting of two-high reversing mill, roller tables with heating panels, cooling devices and controlling-recording systems reflects industrial hot strip rolling parameters sufficiently. Reduction values and temperature-time regimes are similar to those used in industrial practice whereas strain rate is limited to about 10 s-1 what requires taking into account during comparison. All the steels investigated have high total pressure forces due to the high total content of alloying elements. The critical factor making it possible to obtain high-quality sheet samples with a thickness up to 3.3 mm is applying isothermal heating panels which decrease a cooling rate of thin sheets.Research limitations/implications: The real complete simulation of hot strip rolling requires extension of a used line with a further module for simulation of continuous finishing rolling stages. The work is in progress.Practical implications: The results can be successfully utilized in industrial hot rolling and controlled cooling practices after necessary modifications.Originality/value: The efficient semi-industrial physical simulation of hot strip thermomechanical rolling of some new model AHSS grades containing increased Mn and Al content as well as Nb microadditions was presented.

  2. Evaluating the mechanical behavior of hot rolled Al/alumina composite strips using shear punch test

    The evaluation of mechanical properties, like yield and ultimate shear strengths from shear punch tests, is important when availability of material, is limited. A shear punch test setup was built, and the mechanical properties of different strips of hot rolled pure aluminum, post-rolling annealed pure aluminum, as-milled pure aluminum, and 4 wt% Al2O3 were investigated. The materials were first manufactured using powder metallurgy and then processed by hot rolling procedure. Microstructures of the samples were investigated by optical and scanning electron microscopes. It was found that by increasing alumina content in the matrix, shear strength and hardness were increased; also, the percentage of shear elongation was decreased. The results, also, indicated that by applying mechanical milling on pure aluminum powders before the hot rolling process, shear strength and hardness increased more than other samples. Moreover, shear strength was increased by increasing the amount of alumina particles in composite strips. SEM observations demonstrated that the amount of flat surface in shear failure micrographs increased by increasing the amount of shear strength and hardness

  3. 75 FR 17832 - Pricing for 2010 Lincoln One-Cent Coin Two-Roll Set

    2010-04-07

    ... United States Mint Pricing for 2010 Lincoln One-Cent Coin Two-Roll Set AGENCY: United States Mint... 2010 Lincoln One-Cent Coin Two-Roll Set. The 2010 Lincoln One-Cent Coin Two-Roll Set will be priced at $8.95. This set will contain rolls of coins struck at both the United States Mint facilities...

  4. Low Band Gap Polymers for Roll-to-Roll Coated Organic Photovoltaics – Design, Synthesis and Characterization

    Bundgaard, Eva; Hagemann, Ole; Jørgensen, Mikkel;

    2011-01-01

    In this paper we present the design and synthesis of 25 new low band gap polymers. The polymers were characterized by UV-vis spectroscopy which showed optical band gaps of 2.0–0.9 eV. The polymers which were soluble enough were applied in organic photovoltaics, both small area devices with a spin...... coated active layer and in large area modules where all layers including the active layer were either roll-to-roll coated or printed. These experiments showed that the design of polymers compatible with roll-toroll coating is not straightforward and that there are various issues such as donor...

  5. Elastic Deployable Composite Tubular Roll-Out Boom Project

    National Aeronautics and Space Administration — Deployable Space Systems (DSS) has developed an affordable and ultra-lightweight elastically self-deployable Roll-Out Boom technology that provides affordability...

  6. Rolling bearing fault diagnosis using an optimization deep belief network

    The vibration signals measured from a rolling bearing are usually affected by the variable operating conditions and background noise which lead to the diversity and complexity of the vibration signal characteristics, and it is a challenge to effectively identify the rolling bearing faults from such vibration signals with no further fault information. In this paper, a novel optimization deep belief network (DBN) is proposed for rolling bearing fault diagnosis. Stochastic gradient descent is used to efficiently fine-tune all the connection weights after the pre-training of restricted Boltzmann machines (RBMs) based on the energy functions, and the classification accuracy of the DBN is improved. Particle swarm is further used to decide the optimal structure of the trained DBN, and the optimization DBN is designed. The proposed method is applied to analyze the simulation signal and experimental signal of a rolling bearing. The results confirm that the proposed method is more accurate and robust than other intelligent methods. (paper)

  7. Second order perturbations during inflation beyond slow-roll

    We numerically calculate the evolution of second order cosmological perturbations for an inflationary scalar field without resorting to the slow-roll approximation or assuming large scales. In contrast to previous approaches we therefore use the full non-slow-roll source term for the second order Klein-Gordon equation which is valid on all scales. The numerical results are consistent with the ones obtained previously where slow-roll is a good approximation. We investigate the effect of localised features in the scalar field potential which break slow-roll for some portion of the evolution. The numerical package solving the second order Klein-Gordon equation has been released under an open source license and is available for download

  8. PERFORMANCE OF LUBRICATING OIL FILM IN ALUMINIUM FOIL ROLLING

    1999-01-01

    The surface of the aluminum foil rolled has been observed with microscope on the basis of industrial experiments, and the structure of the surface adsorption film has been analyzed by means of low angle X-ray diffraction. It is advanced that the lubrication in aluminum foil rolling is in the state of thin film lubrication, surface adsorption film is an ordered multi-layered molecule film with more than 7 layers; and the layers of the ordered molecule film is influenced by the concentration of the additive in certain range; the concentration of the additive in oil is the main factor affecting the stability of rolling, controling the concentration of the additive can control the ratio of fluid friction, boundary friction, and local holding-on in deformation zone,thus obtaining good rolling deformation conditions.

  9. Rolling bearing fault diagnosis using an optimization deep belief network

    Shao, Haidong; Jiang, Hongkai; Zhang, Xun; Niu, Maogui

    2015-11-01

    The vibration signals measured from a rolling bearing are usually affected by the variable operating conditions and background noise which lead to the diversity and complexity of the vibration signal characteristics, and it is a challenge to effectively identify the rolling bearing faults from such vibration signals with no further fault information. In this paper, a novel optimization deep belief network (DBN) is proposed for rolling bearing fault diagnosis. Stochastic gradient descent is used to efficiently fine-tune all the connection weights after the pre-training of restricted Boltzmann machines (RBMs) based on the energy functions, and the classification accuracy of the DBN is improved. Particle swarm is further used to decide the optimal structure of the trained DBN, and the optimization DBN is designed. The proposed method is applied to analyze the simulation signal and experimental signal of a rolling bearing. The results confirm that the proposed method is more accurate and robust than other intelligent methods.

  10. Corrosion analysis of accumulative roll bonded aluminum 6016

    Searcy, Jacquelyn Alisha

    Accumulative Roll Bonding is a Severe Plastic Deformation Process that is used to strengthen a material and promote grain refinement. Accumulative Roll Bonded Aluminum 6016 samples were investigated to determine their corrosion properties. The tests performed consisted of standard techniques including Cyclic Polarization Potentials, Exfoliation Corrosion (EXCO), Electrochemical Impedance Spectroscopy (EIS), Light Microscopy, and Electron Microprobe Analysis. From these tests, it was determined that for Al 6016, the Ultra Fine Grained samples obtained by Accumulative Roll Bonding are in general more susceptible to corrosion than the coarse grained sample. The higher corrosion rate was caused by the additional cold work, which increased the number of grain boundaries and rolled-in debris. The advantage however was that the corrosion was parallel to the surface and rather than deep into the sample as with the as-received 6016.

  11. Rolling shutter image compensation based on humanoid robot NAO

    Zhao, Shuying; Zhao, Bing; Pan, Feng; Lan, Dongying; Jiang, Longwei; Hu, Xiangliang

    2014-01-01

    According to the requirement of RoboCup Standard Platform League (NAO) Rule Book, the author did some experiments to finish the League's tasks based on the humanoid robot NAO. The image captured by a moving camera will have a distortion which is affected by the so called "rolling shutter". The rolling shutter means that not all scanlines are exposed over the same time interval. This paper presents the model of rolling shutter of cameras and principle of capturing images. Then corrections to image distortion found on the NAO robots is described. At last the cases of reversing the effects of a rolling shutter on the images taken by the robot's moving camera are presented. This approach improves the effectiveness of shape recognition and the accuracy of Tilt rate of field line.

  12. A Mandrel Feeding Strategy in Conical Ring Rolling Process

    Wen Meng

    2014-01-01

    Full Text Available A mathematical model for radial conical ring rolling with a closed die structure on the top and bottom of driven roll, simplified as RCRRCDS, was established. The plastic penetration and biting-in conditions in RCRRCDS process were determined. A mandrel feeding strategy for RCRRCDS process was proposed. The mandrel feed rate and its reasonable value range were deduced. The coupled thermal-mechanical FE model of RCRRCDS process was established. The reasonable value range of the mandrel feed rate was verified by using numerical simulation method. The results indicate that the reasonable value range of the mandrel feed rate is feasible, the proposed mandrel feeding strategy can realize a steady RCRRCDS process, and the forming quality of conical ring rolled by using the proposed feeding strategy is better than that of conical ring rolled by using a constant mandrel feed rate.

  13. Study on detinning process of a reflow conductor roll

    FU Hanguang; DAI Mingshan; FU Hanfeng

    2005-01-01

    Adhering tin is the main reason of a reflow conductor roll which works in an electroplating tin line (ETL). A detinning agent whose main composition is NaOH and KOH and assistant composition is Na2PbO2 or K2PbO2 and NaNO3 or NaNO2 has excellent detinning effects when the temperature of detinning solution is 40-80℃ and the temperature of the reflow conductor roll reaches 40-70℃. After the adhering tin layer of the reflow conductor roll is removed, the roughness of the reflow conductor roll can resume to 4.0 μm, its service life increases by 80%, and the repairing cost decreases by 90%.

  14. Optimal Portfolio Strategy under Rolling Economic Maximum Drawdown Constraints

    Xiaojian Yu

    2014-01-01

    Full Text Available This paper deals with the problem of optimal portfolio strategy under the constraints of rolling economic maximum drawdown. A more practical strategy is developed by using rolling Sharpe ratio in computing the allocation proportion in contrast to existing models. Besides, another novel strategy named “REDP strategy” is further proposed, which replaces the rolling economic drawdown of the portfolio with the rolling economic drawdown of the risky asset. The simulation tests prove that REDP strategy can ensure the portfolio to satisfy the drawdown constraint and outperforms other strategies significantly. An empirical comparison research on the performances of different strategies is carried out by using the 23-year monthly data of SPTR, DJUBS, and 3-month T-bill. The investment cases of single risky asset and two risky assets are both studied in this paper. Empirical results indicate that the REDP strategy successfully controls the maximum drawdown within the given limit and performs best in both return and risk.

  15. Elastic Deployable Composite Tubular Roll-Out Boom Project

    National Aeronautics and Space Administration — DSS's innovative Elastic Deployable Composite Tubular Roll-Out Boom will provide revolutionary performance when compared to conventional state-of-the-art...

  16. Kostnadseffektivering av logistikkostnader : Rolls-Royce Oy Ab

    Nordlund, Lucas

    2013-01-01

    Rolls-Royce Oy Ab som fungerar som uppdragsgivare i detta examensarbete, är ett företag med internationell verksamhet. Företaget hör till det globala Rolls-Royce plc som verkar inom många olika delområden i länder runt om i hela världen. Enheten i Karleby verkar inom Rolls-Royce Marine koncernen och tillverkar vattenjetaggregat. I och med att Rolls-Royce Oy Ab hör till Marine koncernen, medför det att man följer bestämmelser och standarder som följs i hela Marine koncernen. Till dessa gem...

  17. Twin-roll strip casting of magnesium alloys in China

    2008-01-01

    The development status of twin-roll strip casting for magnesium alloys in China was summarized as well as the new progress when several kinds of twin-roll strip casting technologies were developed and used.Horizontal twin-roll casting (HTRC) of magnesium alloys has attracted much attention and has been industrialized in China.Vertical twin roll casting(VTRC) of the magnesium alloys can reach a speed of higher than 30 m/min and its research and development are just beginning and exhibit exciting potential.By comparing the process characteristics of the two technologies,the process stability of HTRC for the magnesium alloys is better,and the casting speed and the cooling rate of VTRC for the magnesium alloys are higher.The quality of the products by the two technologies needs to be improved and further investigated.

  18. Reduction of dispersive ground-roll using time delay spectrometry

    Kjeldsen, Peter Møller; Larsen, Henrik C

    1992-01-01

    Velocity filtering seismic traces requires fulfilment of the sampling theorem in the time domain and in the space domain. Since the latter condition is seldom met in exploration seismics, a method based on τ-p transformation combined with time varying filtering is proposed for solving the problem...... of reducing dispersive ground-roll in a seismic trace. Although it is possible to mask out ground-roll in the τ-p domain, mapping of the τ-p domain back into the original x-t domain involves numerical difficulties because the used inverse discrete Radon transform is ill-posed. To circumvent this...... problem the seismic trace is applied to a time varying filter with a stop-band which at any instant corresponds to the instantaneous frequency of the ground-roll, thus reducing the ground-roll with minimum distortion of the wanted seismic rate...

  19. Dynamic Effect of Rolling Massage on Blood Flow

    The Chinese traditional medical massage has been used as a natural therapy to eliminate some diseases. Here, the effect of the rolling massage frequency to the blood flow in the blood vessels under the rolling massage manipulation is studied by the lattice Boltzmann simulation. The simulation results show that when the frequency is smaller than or comparable to the pulsatile frequency of the blood flow, the effect on the blood flux by the rolling massage is small. On the contrast, if the frequency is twice or more times of the pulsatile frequency of the blood flow, the blood flux is greatly enhanced and increases linearly with respect to the frequency. Similar behavior has also been observed on the shear stress on the blood vessel walls. The result is helpful for understanding that the rolling massage has the function of promoting the blood circulation and removing the blood stasis.

  20. Dynamic Effect of Rolling Massage on Blood Flow

    Chen, Yan-Yan; Yi, Hou-Hui; Li, Hua-Bing; Fang, Hai-Ping

    2009-02-01

    The Chinese traditional medical massage has been used as a natural therapy to eliminate some diseases. Here, the effect of the rolling massage frequency to the blood flow in the blood vessels under the rolling massage manipulation is studied by the lattice Boltzmann simulation. The simulation results show that when the frequency is smaller than or comparable to the pulsatile frequency of the blood flow, the effect on the blood flux by the rolling massage is small. On the contrast, if the frequency is twice or more times of the pulsatile frequency of the blood flow, the blood flux is greatly enhanced and increases linearly with respect to the frequency. Similar behavior has also been observed on the shear stress on the blood vessel walls. The result is helpful for understanding that the rolling massage has the function of promoting the blood circulation and removing the blood stasis.