how to control eccentricity problem in hot rolling mill

  • Non-circular grinding of backup rolls to reduce rolling

    Jun 01 2007 · The steel mills built in the 1960s and 1970s and even later are looking for cost-effective means to meet the new demands. This study discusses a method of reducing the force variation in the milling stand. Typically a rolling mill consists of 1-7 rolling stands. There are usually two three or more rolls in each stand.

  • Loop monitoring and assessment of hot strip mill control

    The object of the thesis work was to test assessment and monitoring tools for the control of a hot strip rolling mill. Two control system were also evaluated work roll bending control and gap control. The effectiveness of a filter that is used within the control to remove the effect of

  • Multi-resolution wavelet method for roll eccentricity

    In order to compensate the roll eccentricity in hot strip rolling process a multi-resolution wavelet transform method was proposed. This wavelet method has quiet good localization characteristic in both time domain and frequency domain. To eliminate frequency aliases inhered in Mallat algorithm an anti-aliasing algorithm combining fast Fourier transform (FFT) and inverse fast Fourier

  • Research on Mill Modulus Control of Strip Rolling AGC

    Jun 01 2007 · Control theories and models related to MMC were studied deeply in this paper. Its ability to eliminate strip thickness deviation rolling force noise and roller eccentricity disturbances were simulated respectively based on different virtual mill modulus with MATLAB. As a result how to get a better control effect was analyzed and confirmed.

  • FAULT DIAGNOSIS OF ROLL SHAPE UNDER THE SPEED

    find both eccentricity magnitude and eccentricity location in the roll as shown in Fig.10. But as shown in Fig.12 not only magnitude of eccentricity but also location of eccentricity in the roll is obtained. 4.2 Simulations with Field Data Fig.13 shows a simplified multi-stand hot rolling system. The rolling system consists of seven stands.

  • Strip Thickness Control of Cold Rolling Mill with Roll

    Nov 12 2013 · been developed for hot or cold mill processes. The Brit-ish Iron and SteelResearch Association (B1SRA) AGC method based on the gaug meter principle and the feede forward AGC method using the delivery time of the strip have been widely utilized in steel rolling mills 3 . Strip products thickness precision is an important quality parameter.

  • Upgrading of Hot Finishing Mill to 4-Stands and

    an overview of the hot finisher mill after the upgrade and describes the new control technology and hot rolling pro-cess control system that were introduced. 2. GENERAL DESCRIPTION The hot rolling mill of the Fukui Works went into service in May 1983 as a world-class facility equipped with large rolling stands capable of producing wide

  • A BASIC UNDERSTANDING OF THE MECHANICS OF

    cooling system. Problems of this kind can never really be calculated but they have a detrimental effect on all rolling schedules including stresses in the roll. As regards "abnormal" rolling conditionswhich are more or less very "normal" for rolling millsroll damage often occurs with consequences for the mill and the rolled product.

  • The development of the theory of metal rolling and its

    The control of rolling is done by a machine or rolling mill. From a control point of view it is necessary to study the combined behavior of machine and metal deformation to find the variables that may be used to most effectively regulate the process. A typical problem in this area is to control the output thick-

  • USAMethod and apparatus for the detection and

    The invention provides a new apparatus for the detection measurement and display of roll and roll bearing eccentricity in a rolling mill and also an apparatus for correction of such eccentricities. The apparatus comprises individual narrow band-pass filter modules each dedicated to the detection and development of a signal corresponding to one eccentricity such as fundamental back-up roll

  • The Hot Rolling Process

    CSI s Hot Strip Mill includes six finishing mills which reduce the thickness of the transfer bar down to the gauge required by the customer or the next process. The rolling speed is set to allow the last stand to perform the final reduction at the finishing temperature between 1500° to 1650°F specified to reach certain mechanical properties.

  • Gauge control using estimate of roll eccentricity

    Having thus described the invention and certain embodiments thereof what is claimed is 1. A method of controlling a rolling mill in which eccentricity of one or more of the roll assemblies of the mill and variations in thickness and/or hardness of material entering the mill ordinarily cause variations in the gauge of the material that exits from the mill the eccentricity of the roll

  • A Flatness Based Approach for the Thickness Control in

    Keywords rolling mill multi-stand mill thickness con-trol tension control flying gauge change non-linear control flatness based control. Abstract A multi-stand rolling mill is a highly complex coupled non-linear system. If the operating point is changing in a wider range the non-linearities can no longer be neglected in the controller

  • Unwind/rewind eccentricity control for rolling mills

    Mar 06 1990 · Unwind/rewind eccentricity control for rolling mills . United States Patent . Abstract A method of rolling material in a rolling mill in which the material is directed from an unwind coil of the material to the mill and/or to a rewind coil of the material from the mill the material being under tension as it is directed to and from the

  • Hot rolling mill process and hot rolled steel sections

    Hot rolling is an industrial process for re-working principally steels but also stainless steels. Steelworks melt the material. To make it transportable the melted steel cools down in different shapes. The process of hot rolling sections. These shapes can be either blooms billets or slabs.

  • Rolling of Steel in small and medium sized Rolling Mills

    Jun 09 2017 · In cross-country rolling mills like in any other hot rolling mills rolling is done above the recrystallization temperature of the steel material. During rolling in these mills the grains which deform during the process of rolling recrystallize maintain an equiaxed microstructure and prevent the steel material from work hardening.

  • USAMethod and apparatus for the detection and

    The invention provides a new apparatus for the detection measurement and display of roll and roll bearing eccentricity in a rolling mill and also an apparatus for correction of such eccentricities. The apparatus comprises individual narrow band-pass filter modules each dedicated to the detection and development of a signal corresponding to one eccentricity such as fundamental back-up roll

  • Roll Eccentricity Extraction Method Based on Comprehensive

    Roll eccentricity is ubiquitous in strip mills which has a periodic impact on the strip thickness difference. Roll eccentricity compensation is an important part of the automatic gauge control system. Most roll eccentricity compensations extract the roll eccentricity based on the frequency domain analysis of the rolling

  • Process and Disturbance Models (Design Case Studies)

    Eccentricity in the rolling cylinders Feedback control is necessary to reduce the effect of these disturbances. Because the roll gap cannot be measured close to the mill stand the rolling force is used instead for feedback. The input thickness disturbance is modeled as

  • Decoupling Control and Simulation of Looper MIMO System

    An optimal multivatiable looper control system based on decoupling strategy has been developed for hot strip finishing mills. Based on the dynamic configuration of the coupling system we can get the status space expression of the coupling loopers system. Through the tools of Matlab we make out of the transfer function of looper system. Based on Decouping-Inbariable character theory and the

  • Hot Rolling Mill Hydraulic Gap Control ( HGC

    In this article the AGC (Automated Gauge Control) system of a hot rolling mill is analyzed and different methods are described to improve its performance. The mill stretch compensation and other disturbances during the rolling process are compensated and a rolling speed dependent adaptive PI controller is developed to accomplish fine thickness control. The improved system has been validated

  • Unwind/rewind eccentricity control for rolling mills

    Mar 06 1990 · Unwind/rewind eccentricity control for rolling mills . United States Patent . Abstract A method of rolling material in a rolling mill in which the material is directed from an unwind coil of the material to the mill and/or to a rewind coil of the material from the mill the material being under tension as it is directed to and from the

  • Actuator/sensor fault diagnosis for an experimental hot

    2. THE HOT ROLLING HILLE MILL 2.1 Brief description The experimental hot rolling Hille mill presented in Fig 1 is used to carry out multi-pass forward-forward or forward-reverse rolling and also complex multi-pass rolling experiments has a three-phase 20hp 400

  • The Complete Technology Book on Hot Rolling of Steel

    then the process is termed as hot rolling. The hot mills using plain rolls were already being employed by the end of the seventeenth century. But the industrial revolution in the nineteenth century saw a new horizon in Roll Eccentricity Control Methods Passive roll eccentricity control methods Active roll eccentricity control methods

  • CiteSeerX — ROLL ECCENTRICITY CONTROL WITH THE FORCE

    CiteSeerXDocument Details (Isaac Councill Lee Giles Pradeep Teregowda) The Force Feed Forward (FFF) System is the only hot strip mill AGC system in the world today which does not incorporate the BISRA principle for gage control. Instead using a revolutionary control algorithm FFF has proven in five installations in North and South America that steelmakers need not replace their

  • Modernization of a Tandem Cold Rolling Mill at Arcelor

    Direct tension control and coil eccentricity compensation Flatness control (skewing bending partial cooling) Mathematical process models and simulation An ABB in-house non-linear mathematical model was used for the pre-commissioning of the rolling mill. This consists of modular structures for 1- to n-stand rolling mills.

  • CiteSeerX — ROLL ECCENTRICITY CONTROL WITH THE FORCE

    CiteSeerXDocument Details (Isaac Councill Lee Giles Pradeep Teregowda) The Force Feed Forward (FFF) System is the only hot strip mill AGC system in the world today which does not incorporate the BISRA principle for gage control. Instead using a revolutionary control algorithm FFF has proven in five installations in North and South America that steelmakers need not replace their

  • Seamless steel pipe produces eccentricity (uneven

    Mar 27 2019 · The picture above shows the seamless steel pipe perforation site. The eccentricity of many steel pipes is generated at this time so it is very important to strictly control this perforation. Finished steel pipe Cold drawn steel pipe can also cause eccentricity problems due to perforation

  • Advanced Process and Quality Control in Hot Rolling Mills

    3.1 Key Feature of Process Control Detection of Periodic Defects Rolls and rollers are the most heavily used parts of a rolling mill. Due to wear from contacting hot material with great force their lifetime is limited. Although rolls are refurbished in the roll shop regularly they occasionally crack before the end of the usual production cycle.

  • Rolling of Steel in small and medium sized Rolling Mills

    Jun 09 2017 · In cross-country rolling mills like in any other hot rolling mills rolling is done above the recrystallization temperature of the steel material. During rolling in these mills the grains which deform during the process of rolling recrystallize maintain an equiaxed microstructure and prevent the steel material from work hardening.

  • Roll Eccentricity Control for Strip Rolling Mills

    An in-depth review of the roll eccentricity control design problem is provided which encompasses a number of recent novel design contributions and includes experimental results from two separate steel tandem cold rolling mill installations.

  • Advanced Reversing Cold Mills by Primetals Technologies

    Rolling schedules can be carried out with an even or odd number of passes to maximize mill availability and performance. The Universal Crown Control mill (UCM mill) with work roll bending intermediate roll bending intermediate roll shifting and all straight roll application ensure enhanced flatness control.

  • Advanced Process and Quality Control in Hot Rolling Mills

    3.1 Key Feature of Process Control Detection of Periodic Defects Rolls and rollers are the most heavily used parts of a rolling mill. Due to wear from contacting hot material with great force their lifetime is limited. Although rolls are refurbished in the roll shop regularly they occasionally crack before the end of the usual production cycle.

  • The Complete Technology Book on Hot Rolling of Steel

    then the process is termed as hot rolling. The hot mills using plain rolls were already being employed by the end of the seventeenth century. But the industrial revolution in the nineteenth century saw a new horizon in Roll Eccentricity Control Methods Passive roll eccentricity control methods Active roll eccentricity control methods

  • HOT ROLLING PRACTICEAn Attempted Recollection

    motors. These are known as mill stands. The layout of a rolling mill varies from a simple single stand mill to several stands positioned either side by side or in a line. A mechanism commonly called a roller table directs the work piece to the rolls and another roller table for

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