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Sample records for roll mill grinding

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

    Energy Technology Data Exchange (ETDEWEB)

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

    Institute of Scientific and Technical Information of China (English)

    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.

  3. Influence of grinding method and grinding intensity of corn on mill energy consumption and pellet quality

    Directory of Open Access Journals (Sweden)

    Vukmirović Đuro M.

    2016-01-01

    Full Text Available In recent years there is an emerging trend of coarse grinding of cereals in production of poultry feed due to positive influence of coarse particles on poultry digestive system. Influence of grinding method (hammer mill vs. roller mill and grinding intensity of corn (coarseness of grinding on mill specific energy consumption and pellet quality was investigated. By decreasing grinding intensity of corn (coarser grinding, specific energy consumption of both hammer mill and roller mill was significantly decreased (p < 0.05. When comparing similar grinding intensities on hammer mill and roller mill (similar geometric mean diameter or similar particle size distribution, specific energy consumption was higher for the hammer mill. Pellet quality decreased with coarser grinding on hammer mill but, however, this effect was not observed for the roller mill. Generally, pellet quality was better when roller mill was used. It can be concluded that significant energy savings could be achieved by coarser grinding of corn before pelleting and by using roller mill instead of hammer mill. From the aspect of pellet quality, if coarser grinding is applied it is better to use roller mill, concerning that more uniform particle size distribution of corn ground on roller mill probably results in more uniform particle size distribution in pellets and this provides better pellet quality. [Projekat Ministarstva nauke Republike Srbije, br. III 46012

  4. Research on product size and grinding dynamics of vibration mills

    Institute of Scientific and Technical Information of China (English)

    YIN Zhong-jun; HAN Tian; CHEN Bing; ZHANG Wen-zhong

    2007-01-01

    In order to improve vibration mills grinding effect and increase productive efficiency, prime factors of vibration mills were gained much attention. The purpose of this study is to reveal product size distribution and grinding dynamics of vibration mills by orthogonal experi-ments. The metallurgical refractory materials were used as research object. In order to explore the relationships between grinding effect and primary factors, lots of milling experiments were carried out. Based on the results, the conclusions can be summarized: as time runs, the size distri-bution shows exponential trend, and range becomes more and more narrow. Also the quantitative analysis result between grinding effect and primary factors was obtained by non-linear regres-sion: high frequency, high amplitude and low fill ratio can increase grinding speed.

  5. ROLLING MILL SYSTEM DYNAMIC DESIGN

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It is studied how the aluminum foil chatter mark is produced and controlledThe stableness of hydraulic AGC system,fluid vibration of capsule system,and electromechanical coupling of AC/AC VVVF system and dec oupling are also studiedIt is shown that rolling mill design should go to syst em dynamic design from traditional designThe framed drawing of system dynamic design program is presented

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

    Directory of Open Access Journals (Sweden)

    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.

  7. Control for Cold Rolling Mills

    OpenAIRE

    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 ...

  8. Numerical analysis of grinding power consumption of a vertical planetary mill

    Institute of Scientific and Technical Information of China (English)

    HAO Xue-di; ZHU Dong-mei; BIAN Zhi-rui; WANG Xin

    2008-01-01

    Planetary wheel rolling on a coal-bed was simplified as rigid wheel rolling on the coal-bed with a rigid base when a Vertical planetary mill (VPM) is running. Based on our analysis, we conclude that the Bekker formulation for computing rolling resistance is not applicable to calculate directly the rolling resistance of the wheel. According to the principle of the Bekker apparatus, pressure-sinkage curves were obtained by tests on a piece of mono-axial consolidation apparatus used in soil-mechanics. The deformation modulus of the coal-bed was calculated using elastic mechanics. A finite element model of the planetary wheel coal-bed was built up by the use of a rigid and a Drucker-Prager material model in LS-DYNA. According to the simulation results, the wheel rolling resistance, the grinding power consumption and the motor power of the mill were calculated and the mistake in the initial design of the mill was modified. The simulation results agree well with the results of the semi-industrial tests.

  9. Evaluation of Recycle Grinding Performance in Flour Milling

    Science.gov (United States)

    Mazlina Mustapa Kamal, Siti; Webb, Colin

    A typical flour milling process is a very linear operation that is almost entirely void of recycled streams where separate fractions from each operation go ahead as new streams to the next operation. In some cases, there are opportunities for combining some streams, for recycling particles that have been insufficiently broken to go back to the same roller mill. This study introduces this recycle concept in flour milling process at second break system. The recycle grinding assessment was made using a Satake STR-100 test roller mill. The recycle process was started after the second break system and the number of recycle grinding was up to 7 regrinds. The particle size distribution and ash analysis were produced to describe the behaviour of the recycle grinding performance. The material release was sifted on a range of sieves and the ash content was analysed using a laboratory furnace. The performance for each recycle stage was investigated. It was determined that it is possible for some coarse particles that contain only bran to keep being recycled in the recycle circuit. A purging operation was recommended to be included in the recycle system, to separate the unwanted particles.

  10. Grinding process within vertical roller mills: experiment and simulation

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-huai; CHEN Qing-ru; KUANG Ya-li; LYNCH A J; ZHUO Jin-wu

    2009-01-01

    Based on screening analysis, laser size analysis, grindability and rigidity tests of samples collected on line from a cement and a power plant, a simulation of the grinding process in vertical roller mills was carried out. The simulation calculation used a breakage function, B. The results indicate that the breakage function, B, and the selection function, S, in the form of a matrix, can be used to express the probability of the material breaking during the grinding process. This allows the size distribution of the product to be numerically estimated. The simulation results also show that the simulated size distribution curves fit the actual ex-perimental product curves quite well. The model provides a good starting point for simulation of the grinding process. Further re-search is needed to determine the proper breakage function and the matrix value of the selection function.

  11. Improvement on strip flatness of cold temper mills by modifying roll contour shape

    Institute of Scientific and Technical Information of China (English)

    Xiaoyan Li; Jie Zhang; Xianlin Chen; Jianguo Cao; Haixia Li

    2004-01-01

    A study on roll gap profile (strip profile) control was accomplished in a 1700 mm single-stand temper mill. Some critical problems such as the deviation of work roll contour caused by grinding and wear, the effectiveness of work roll bending were discussed. Using a finite element model, the effects of roll contours (ground and wear) on strip profile were investigated. The roll bending effect on strip thickness was also analyzed. It is pointed out that there are some special features of flatness control in the temper mill: during temper rolling, roll deformation is slight due to small rolling load, and the loaded roll gap profile mainly depends on work roll contour, while the backup roll has a little effect on gap crown; the effect of bending force on gauge can not be ignored due to the coupling between flatness control and gauge control. A new roll contour arrangement adaptable to the mill was presented and has been put into practical production. The application of the new set of rolls showed some good results: larger crown control range of work roll bender, higher rolling stability, better strip profile and flatness quality.

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

    Directory of Open Access Journals (Sweden)

    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

  13. Research on work roll thermal crown in cold rolling mill

    Science.gov (United States)

    Song, Lei; Shen, Mingang; Chen, Xuebo; Wang, Junsheng

    2013-05-01

    The factors which have influence on the work roll thermal crown in cold strip rolling are discussed. The heat transferring in three directions (radial axis and circumference) were considered for calculating the work roll thermal deformation. Therefore, it is a three dimensions unstable system for the work roll temperature calculation. The plastic deformation work and friction heat are calculated by the divided element and digital integration method. The simplified calculation model is built for the heat transferring along work roll. There are four zones for work roll heat transferring: roll gap zone air cooling zone emulsion zone rolls contact zone. The heat transferring between the zones is decided by the temperature difference. The inter temperature field and thermal deformation of work roll can be calculated by two-dimension finite difference method. The work roll temperature and thermal crown of actual application cold rolling mill are analyzed by the model. By the comparison between calculated values and measured values, the work roll thermal calculation model can meet the accuracy requirement of on-line control.

  14. ELECTRO-RESISTANCE METHOD OF CHECK A PROCESS GRINDING THE ROLLING BEARINGS

    Directory of Open Access Journals (Sweden)

    K. V. Podmasteryev

    2015-01-01

    Full Text Available Base a possibility of monitoring processes of grinding the rolling bearings with use electroresistance method of check. Is write of essence this method, are analyses his peculiarities, which are provide objective information on the condition a object by his grinding. Are consider the results of experimental researches the effective different diagnostically parameters, which are confirm a possibility of realization objective check of grinding the rolling bearings with use electro-resistance method.

  15. Roll Gap Crown Adjustment Characteristics of 1700 mm Cold Rolling Mills

    Institute of Scientific and Technical Information of China (English)

    GUO Jian-bin

    2014-01-01

    The 4-hi cold mill is one of the key wide strip tandem cold rolling mills and has many advantages and characteristics. The mill type is the most important, fundamental and long-term effective factor for the strip shape control. Many advanced mill types such as CVC-4, HCW and PC-4, etc are created based on the conventional four-roll mill. The factors of mill type which affect the deformation of roll system, such as strip width, rolling force, bending force, work roll diameter, backup diameter and so on, are studied how to affect roll gap crown. It provides a good foundation for improving the shape performance of mill.

  16. Investigation for parametric vibration of rolling mill

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  18. Research on Frequency Response Characteristics of Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    CaiZhengguo; ZhangKenan

    2005-01-01

    The measurement method of frequency response characteristics for rolling mill is established by imposing different signal excitation on PID input of rolling mill under the different rolling conditions. The analysis results declare that sweep sine signal was relative efficient to evaluation for the frequency response character of hydraulic system. The practical application shows that the corresponding relationship between the parameters and the frequency response range of the rolling mill is helpful for parameters verification of process control and condition monitoring of hydraulic system.

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

    Directory of Open Access Journals (Sweden)

    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

  20. Automatic Flatness Control of Cold Rolling Mill

    Science.gov (United States)

    Anbe, Yoshiharu; Sekiguchi, Kunio

    One of the subjects of cold rolling is a flatness of the rolled strip. Conventionally, measured strip flatness was approximated by polynomial (2th, 4th, 6th) equation across the entire strip width. This made it difficult to deal with desired loose edge or any desired flatness across the entire strip width. Also conventional flatness control was done for the entire strip width, so if there is a different flatness error among drive side and work side, conventional flatness control can not control properly. We propose independent strip flatness control among drive side and work side, and also automatic flatness control (AFC) system with arbitrary desired strip flatness. Also some applied results to cold mill are shown.

  1. Dynamic estimation of electrical demand in hot rolling mills

    OpenAIRE

    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, ...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Properties of Cross-Rolled Low Alloy White Cast Iron Grinding Ball

    Institute of Scientific and Technical Information of China (English)

    CHANG Li-min; LIU Lin; LIU Jian-hua

    2007-01-01

    The low-energy, multi-impact fracture resistance and the abrasiveness of the cross-rolled low alloy white cast iron grinding balls were studied after heat treatments at residual rolling temperature. Moreover, the means by which they are damaged and characters of the wear surface were analyzed. The results show that high resistance to impact fracture and high abrasiveness can be achieved after appropriate heat treatment at residual rolling temperature. This kind of heat treatment technology has several advantages under low impact and hard abrasive. These results are very useful for determining the optimized heat treatment technology at residual rolling temperatures.

  4. Strip shape control capability of hot wide strip rolling mills

    Institute of Scientific and Technical Information of China (English)

    Renzhong Wang; Quan Yang; Anrui He; Jian Shao; Haitao Bian

    2008-01-01

    The elasticity deformation of rolls was analyzed by means of two-dimensional f'mite element method (FEM) with vari-able thickness. Three typical mills were used as objects for analysis. A thorough study was done on the control capabilities of these mills on the strip shape. Then the strip shape control capabilities of the three mills was compared synthetically.

  5. Role of classification in grinding using the electromagnetic mill. A case study

    Directory of Open Access Journals (Sweden)

    Wolosiewicz-Glab Marta

    2016-01-01

    Full Text Available In the process of classification, one of the methods used to evaluate the effectiveness classifiers is to plot a separation curve, which determines the size of seprated particles and characterizes the process accuracy. The article presents an assessment of the impact of parameters on grinding and classification using an electromagnetic mill. The results allow a detailed assessment of the effectiveness and efficiency of the device and facilitate the optimization of the grinding process by establishing an appropriate control algorithms.

  6. THEORETICAL AND EXPERIMENTAL STUDIES OF ENERGY-EFFICIENT GRINDING PROCESS OF CEMENT CLINKER IN A BALL MILL

    Directory of Open Access Journals (Sweden)

    Kuznetsova M.M.

    2014-08-01

    Full Text Available The article presents results of theoretical and experimental research of grinding process of bulk materials in a ball mill. The new method of determination of energy efficiently mode of operation of ball mills in a process of a cement clinker grinding is proposed and experimentally tested.

  7. Influence of pin and hammer mill on grinding characteristics, thermal and antioxidant properties of coriander powder.

    Science.gov (United States)

    Barnwal, P; Singh, K K; Sharma, Alka; Choudhary, A K; Saxena, S N

    2015-12-01

    In present study, influence of grinding (hammer and pin mills) and moisture content (range: 6.4-13.6 % dry basis) on the quality traits of coriander powder were investigated. These include grinding parameters, colour parameters, specific heat, thermal conductivity, thermal diffusivity, glass transition temperature, essential oil, total phenolic content, total flavonoid content and DPPH scavenging (%) of coriander powder. For coriander seed, the geometric properties such as major, medium, minor dimensions, geometric mean diameter, arithmetic mean diameter, sphericity, surface area and volume of coriander seeds increased significantly with increasing moisture (6.4-13.6 % db). For coriander powder, the grinding parameters such as average particle size, volume surface mean diameter and volume mean diameter increased significantly with increasing moisture (6.4-13.6 % db). With the grinding method, the colour attributes of coriander powder such as L-value, a-value, b-value, hue angle and browning index varied significantly. It was observed that the specific heat followed second order polynomial relationship with temperature and moisture whereas thermal conductivity varied linearly with temperature and moisture content. The variation of glass transition temperature with moisture can be best represented in quadratic manner. Total flavonoid content (mg QE/g crude seed extract) and DPPH scavenging % activity of coriander powder is significantly affected by grinding methods. A lower value of specific heat was observed for hammer ground coriander powder as compared to pin mill ground coriander powder. The thermal conductivity of hammer mill ground coriander powder was higher as compared to pin mill ground coriander. It was observed that hammer mill yields more fine coriander powder in comparison to pin mill. The browning index was more in hammer mill ground coriander powder. PMID:26604351

  8. Optimum condition determination of Rirang uranium ores grinding using ball mill

    International Nuclear Information System (INIS)

    The grinding experiment on Rirang Uranium ore has been carried out with the aim is to find out the optimum condition of wet grinding using ball mill to produce particle size -325, -200 and -100 mesh. This will be used for decomposition feed the test was done by examine the parameters comparison of ore's weight against ball's weight and time of grinding. The test shown that the product of particle size -325 meshes was achieved optimum condition at the comparison ore's weight: ball = 1:3, grinding time 150 minutes, % solid 60, speed rotation of ball mill 60 rpm and recovery of grinding was 93.51 % of -325 mesh. The product of particle size -200 mesh was achieved optimum condition at comparison ore's weight: ball = 1:2, time of grinding 60 minutes, the fraction of + 200 mesh was regrind, the recovery of grinding 6.82% at particle size of (-200 + 250) mesh, 5.75 % at (-250 + 325)m mesh and, 47.93 % -325 mesh. The product of particle size -100 mesh was achieved the optimum condition at comparison ore's weight: ball = 1:2, time of grinding at 30 minutes particle size +100 mesh regrinding using mortar grinder, recovery of grinding 30.10% at particle size (-100 + 150) m, 12.28 % at (-150 + 200) mesh, 15.92 % at (-200 + 250) mesh, 12.44 % at (-250 + 325) mesh and 29.26 % -325 mesh. The determination of specific gravity of Rirang uranium ore was between 4.15 - 4.55 g/cm3

  9. Evaluation of Flatness Gauge for Hot Rolling Mills

    OpenAIRE

    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...

  10. Modeling for driving systems of four-high rolling mill

    Institute of Scientific and Technical Information of China (English)

    贺建军; 喻寿益; 钟掘

    2002-01-01

    A modeling method for driving systems of four-high rolling mill was put forward in order to analyze the origin of rolling mill's chatter that brings about light and shade streaks on the surface of steel strip from aspect of electromechanical coupling. The process and steps of modeling method was introduced by means of an example. The correctness of the model and the feasibility of the modeling method were verified in simulation experiment.

  11. Use of sleeved rolls in a blooming mill

    Science.gov (United States)

    Kuhn, G.

    1983-03-01

    The use of sleeved rolls in the blooming stand ahead of a continuous semifinishing mill is treated. Two sleeved rolls were produced. One comprises a tough steel arbor and the wear resistant roll sleeve of Cr-Ni-Mo-alloyed spheroidal cast iron with carbide. Both parts were joined together in an unstressed manner by adhesive bonding. Tests show that sleeved rolls can be used in blooming stands, thereby increasing their application possibilities, but porosity in the finishing grooves of the rolls caused during the casting process means that long term behavior can not be assessed.

  12. Investigation for Electromechanical Coupling Unstability of Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    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. ...

  13. Rolling Resistance and Mechanical Properties of Grinded Copper Surfaces Using Molecular Dynamics Simulation.

    Science.gov (United States)

    Liang, Shih-Wei; Wang, Chih-Hao; Fang, Te-Hua

    2016-12-01

    Mechanical properties of copper (Cu) film under grinding process were accomplished by molecular dynamics simulation. A numerical calculation was carried out to understand the distributions of atomic and slip vector inside the Cu films. In this study, the roller rotation velocity, temperature, and roller rotation direction change are investigated to clarify their effect on the deformation mechanism. The simulation results showed that the destruction of materials was increased proportionally to the roller rotation velocity. The machining process at higher temperature results in larger kinetic energy of atoms than lower temperature during the grinding process of the Cu films. The result also shows that the roller rotation in the counterclockwise direction had the better stability than the roller rotation in the clockwise direction due to significantly increased backfill atoms in the groove of the Cu film surface. Additionally, the effects of the rolling resistances on the Cu film surfaces during the grinding process are studied by the molecular dynamics simulation method. PMID:27637893

  14. Rolling Resistance and Mechanical Properties of Grinded Copper Surfaces Using Molecular Dynamics Simulation

    Science.gov (United States)

    Liang, Shih-Wei; Wang, Chih-Hao; Fang, Te-Hua

    2016-09-01

    Mechanical properties of copper (Cu) film under grinding process were accomplished by molecular dynamics simulation. A numerical calculation was carried out to understand the distributions of atomic and slip vector inside the Cu films. In this study, the roller rotation velocity, temperature, and roller rotation direction change are investigated to clarify their effect on the deformation mechanism. The simulation results showed that the destruction of materials was increased proportionally to the roller rotation velocity. The machining process at higher temperature results in larger kinetic energy of atoms than lower temperature during the grinding process of the Cu films. The result also shows that the roller rotation in the counterclockwise direction had the better stability than the roller rotation in the clockwise direction due to significantly increased backfill atoms in the groove of the Cu film surface. Additionally, the effects of the rolling resistances on the Cu film surfaces during the grinding process are studied by the molecular dynamics simulation method.

  15. Rolling Resistance and Mechanical Properties of Grinded Copper Surfaces Using Molecular Dynamics Simulation.

    Science.gov (United States)

    Liang, Shih-Wei; Wang, Chih-Hao; Fang, Te-Hua

    2016-12-01

    Mechanical properties of copper (Cu) film under grinding process were accomplished by molecular dynamics simulation. A numerical calculation was carried out to understand the distributions of atomic and slip vector inside the Cu films. In this study, the roller rotation velocity, temperature, and roller rotation direction change are investigated to clarify their effect on the deformation mechanism. The simulation results showed that the destruction of materials was increased proportionally to the roller rotation velocity. The machining process at higher temperature results in larger kinetic energy of atoms than lower temperature during the grinding process of the Cu films. The result also shows that the roller rotation in the counterclockwise direction had the better stability than the roller rotation in the clockwise direction due to significantly increased backfill atoms in the groove of the Cu film surface. Additionally, the effects of the rolling resistances on the Cu film surfaces during the grinding process are studied by the molecular dynamics simulation method.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  17. ALSTOM Schusselmuhle fur die feinvermahlung von anhydrit ALSTOM bowl mill for anhydrite fine grinding

    CERN Document Server

    Angleys, M

    2003-01-01

    After the ALSTOM bowl mill had proved a success during numerous laboratory tests using different industrial minerals, for the first time a mill, type SM 20/12 was commissioned for ATLAS s.c. at Lodz /Poland for anhydrite grinding. Based on corresponding laboratory tests with anhydrite, it was possible to adapt the equipment to the requirements of the material with modified properties. Due to the project preparation together with the customer, the mill could be installed and commissioned according to schedule by a joint team of engineers for erection and commissioning.

  18. DESIGN OF INTELLIGENT CONTROL SYSTEM USING ACOUSTIC PARAMETERS FOR GRINDING MILL OPERATION

    Directory of Open Access Journals (Sweden)

    Sonali Sen

    2013-02-01

    Full Text Available This paper utilizes acoustic parameters such as FS,NC, N, P, INC, FL, FH, W for acoustic signals S of different running conditions of a ballmill to deriveout the acoustic signatures and hence control signals, which is to be used for designing the control systems of the mill. The parameters FS, NC, N, P, INC, FL, FH and W are represented by sample rate in Hz, number of cepstral coefficients, length of frame in samples, number of filters in filter bank, frame increment, low end of the lowest filter, high end of highest filter and the window over which the analysis is to be performed respectively. The work establishes an appropriate theoretical background that helps to predict dynamic breakage characteristics with respect to particle size distribution of materials, adequately supported by experimental data. The signatures of different running conditions of grinding mill have been extracted from the captured signal in time frame these have been used as feedback signal to monitor the grinding operation. Condenser based microphones have been used for capturing acoustic signals in time domain directly in computers and stored for further analysis. Matlab R2010b has been used for different analysis of the experiment. On analyzing the signatures, it has been observed whether the fines are produced progressively to attain the desired size range or the mill producing undesired products. Thus, the approach has been used in this paper has the ability to arrive in the stage of optimum grinding by tuning parameters of the mill in real time, and also it can prevent the mill to enter into an erroneous state. Moreover, on study it has found that the present scheme can be used more accurately in comparison to the earlier work of the author. This paper presents an implementation scheme to use acoustic signal as the control signal to regulate the operation of a grinding mill.

  19. Corrosion of Cast Iron Mill Plates in Wet Grinding

    Directory of Open Access Journals (Sweden)

    Anthony ANDREWS

    2010-12-01

    Full Text Available Corrosion studies were carried out on two different maize grinding plates. Maize was soaked in water for three days and the water decanted and used as electrolyte. Mass loss and pH measurements were carried out every 3 days for 15-day period. Results show that, for each plate, mass loss and pH increased with exposure time. Corrosion rates determined from mass loss data was found to be strongly dependent on pH. The observed behaviour may be explained in terms of the chemical composition and/or microstructures of the plates. Results are briefly discussed in terms of the contribution of corrosion to wear.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  1. Energy efficiency of cement finish grinding in a dry batch ball mill

    OpenAIRE

    Touil, Djamel; Belaadi, Salah; Frances, Christine

    2006-01-01

    Dry grinding experiments on cement clinker were carried out using a laboratory batch ball mill equipped with torque measurement. The specific energy was found to be dependent on operating parameters and clinker environment. Additional compounds such as gypsum and pozzolanic tuff improve energy efficiency. The optimal parameters allowing maximising the energy efficiency factor were determined. Energy efficiency factors were obtained both on the crude material (size minus 2.8 mm) and on a sieve...

  2. Experimental Study of Machinability in Mill-grinding of SiCp/Al Composites

    Institute of Scientific and Technical Information of China (English)

    LI Jianguang; DU Jinguang; YAO Yingxue; HAO Zhaopeng; LIU Xiao

    2014-01-01

    An attempt was made to investigate the machinability of SiCp/Al composites based on the experimental study using mill-grinding processing method. The experiments were carried out on a high-speed CNC machining center using integrated abrasive cutting tool. The effects of combined machining parameters, e g, cutting speed (vs), feed rate (vf), and depth of cut (ap), with the same change of material removal rate (MRR) on the mill-grinding force and surface roughness (Ra) were investigated. The formation mechanism of typical machined surface defects was analyzed by SEM. The experimental results reveal that with the same change of material removal rate, lower mill-grinding force values can be gained by increasing depth of cut and feed rate simultaneously at higher cutting speed. With the same change of MRR value, lower surface roughness values can be gained by increasing the feed rate at higher cutting speed, rather than just increasing the depth of cut, or increasing the feed rate and depth of cut simultaneously. The machined surface of SiCp/Al composites reveals typical defects which can influence surface integrity.

  3. Complete Mill Simulation of the Rolling Process of 1660 mm Hot Strip Continuous Mills

    Institute of Scientific and Technical Information of China (English)

    Yingrui WANG; Zhenshan CUI; Yingjie WANG; Hongmin LIU

    2004-01-01

    The three-dimensional plastic deformations of strip are analyzed using the stream surface strip element method, the elastic deformations of rolls are analyzed using the influence coefficient method, the analyzing and computing model of shape and crown of 4-high mill was established by combining them, and the rolling process of 1660 mm hot strip continuous mills was simulated. The simulated results tally well with the experimental results. The model and the method for simulation of shape analysis and control of hot strip mills were provided.

  4. SUBSTANTIATION OF KEY PARAMETERS OF A CENTRIFUGAL MILL INTENDED FOR GRINDING SOLID RESIDUE FROM THE PYROLYSIS OF USED AUTOMOBILE TYRES

    Directory of Open Access Journals (Sweden)

    Igor OSTASHKO

    2016-06-01

    Full Text Available The study presents the results of an investigation into centrifugal mills with an energy-saving working body. Rational geometric parameters of the working body of the centrifugal mill, which grinds the solid residue from the pyrolysis of used tyres, have been justified on the criterion of the lowest specific energy consumption during the grinding process. A method to determine the dependence of the in-grinding power consumption on the basic parameters of the working body has been developed, while an analytical expression to determine the power consumption for grinding the solid residue from the pyrolysis of used tyres has been obtained. It has been found that the power consumption in the grinding process linearly depends on the rotational speed of the working body, which is to the 0.3 power on the average size of solid particles.

  5. The effect of cryogenic grinding and hammer milling on the flavour quality of ground pepper (Piper nigrum L.).

    Science.gov (United States)

    Liu, Hong; Zeng, Fankui; Wang, Qinghuang; Ou, Shiyi; Tan, Lehe; Gu, Fenglin

    2013-12-15

    In this study, we compared the effects of cryogenic grinding and hammer milling on the flavour attributes of black, white, and green pepper. The flavour attributes were analysed using headspace solid-phase micro-extraction (HS-SPME) and gas chromatography-mass spectrometry (GC/MS), sensory evaluation and electronic nose (e-nose) analysis. Cryogenic grinding resulted in minimal damage to the colour, flavour, and sensory attributes of the spices. Cryogenic grinding was also better than hammer milling at preserving the main potent aroma constituents, but the concentrations of the main aroma constituents were dramatically reduced after storing the samples at 4 °C for 6 months. Pattern matching performed by the e-nose further supported our sensory and instrumental findings. Overall, cryogenic grinding was superior to hammer milling for preserving the sensory properties and flavour attributes of pepper without significantly affecting its quality. However, we found that the flavour quality of ground pepper was reduced during storage.

  6. Modeling and identification of HAGC system of temper rolling mill

    Institute of Scientific and Technical Information of China (English)

    HE Shang-hong; ZHONG Jue

    2005-01-01

    Including servo valve, hydraulic cylinder, mill and sensor and ignoring nonlinear factors, the linear dynamic model of hydraulic automatic gage control(HAGC) system of a temper rolling mill was theoretically derived. The order of the model is 4/4, and can be reduced to 2/2. Based on modulating functions method, utilizing numerical integration, we constructed the equivalent identification model of HAGC, and the least square estimation algorithm was established. The input and output data were acquired on line at temper rolling mill in Shangshai Baosteel Group Corporation, and the continuous time model of HAGC system was estimated with the proposed method. At different modulating window intervals, the estimated parameters changed remarkably. When the frequency bandwidth of modulating filter matches that of estimated system, the parameters can be estimated accurately. Finally, the dynamic model of the HAGC was obtained and validated based on the spectral analysis result.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    International Nuclear Information System (INIS)

    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

  9. A contact-type tensionmeter for hot rolling mills

    Science.gov (United States)

    Zhao, Xiaoyan; Zhang, Zhaohui; Sun, Yikang; Wang, Jun; Que, Cheng

    2008-12-01

    To improve the hot rolled strip quality and operational stability, a novel tensionmeter based on lever principle is developed which inspects latent waves and provides real references for flatness control in hot rolling process. The contact-type tensionmeter including two segmented rolls can get the transverse tension distribution along the strip width. Tension profile is deduced by different ratio of four force values from the embedded force sensors in tensionmeter system. The compact mechanical structure ensures the tensionmeter's robust stability in hot rolling process, standard hardware and software for data acquisition make the system easy to operate and maintain. The trails have proven tensionmeter successful in improving both strip flatness and mill performance.

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

    Energy Technology Data Exchange (ETDEWEB)

    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)

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

    Directory of Open Access Journals (Sweden)

    Dongxiao Hou

    2014-01-01

    Full Text Available 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. The characteristics of amplitude frequency under nonlinear stiffness, damping, and amplitude of the disturbance are obtained by adopting the actual parameters of 1780 rolling mills. Finally, the bifurcation behavior of the system is studied, and it is found that many dynamic behaviors such as period, period-3 motion, and chaos exist in rolling mill, and this behavior could be restrained effectively by choosing proper system parameters.

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

    Science.gov (United States)

    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.

  13. Application of mechano-chemical synthesis for protective coating on steel grinding media prior to ball milling of copper

    Indian Academy of Sciences (India)

    Indranil Lahiri; K Balasubramanian

    2007-04-01

    One of the major sources of contamination during mechanical milling/alloying is from the surface erosion of the container and the grinding medium. This can either be prevented by using grinding medium and container of same material of the milled material or by adding a coating of the milled material on them. The paper describes the observations made during a mechano-chemical reaction, being used for coating the balls and vials in a planetary ball mill. Visual observation, XRD, optical micrography and EDS analysis were used to understand the progress of the reaction. Copper was successfully coated on the steel balls and vials. The method can easily be adopted in daily production purposes, prior to mechanical milling of a Cu-based powder for prevention of Fe contamination.

  14. Development of rolling mill for rectangular orthodontic wires production

    Directory of Open Access Journals (Sweden)

    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

  15. Flatness Control Using Roll Coolant Based on Predicted Flatness Variation in Cold Rolling Mills

    Science.gov (United States)

    Dohmae, Yukihiro; Okamura, Yoshihide

    Flatness control for cold rolling mills is one of the important technologies for improving of product quality and productivity. In particular, poor flatness leads to strip tearing in the extreme case and, moreover, it significantly reduces productivity. Therefore, various flatness control system has been developed. The main actuators for flatness control are classified into two types; one is mechanical equipment such as roll bender, the other is roll coolant, which controls thermal expansion of roll. Flatness variation such as center buckle or edge wave is mainly controlled by mechanical actuator which has high response characteristics. On another front, flatness variation of local zone can be controlled by roll coolant although one's response is lower than the response of mechanical actuator. For accomplishing good flatness accuracy in cold rolling mills, it is important to improve the performance of coolant control moreover. In this paper, a new coolant control method based on flatness variation model is described. In proposed method, the state of coolant spray on or off is selected to minimize the flatness deviation by using predicted flatness variation. The effectiveness of developed system has been demonstrated by application in actual plant.

  16. Rolling mill optimization using an accurate and rapid new model for mill deflection and strip thickness profile

    Science.gov (United States)

    Malik, Arif Sultan

    This work presents improved technology for attaining high-quality rolled metal strip. The new technology is based on an innovative method to model both the static and dynamic characteristics of rolling mill deflection, and it applies equally to both cluster-type and non cluster-type rolling mill configurations. By effectively combining numerical Finite Element Analysis (FEA) with analytical solid mechanics, the devised approach delivers a rapid, accurate, flexible, high-fidelity model useful for optimizing many important rolling parameters. The associated static deflection model enables computation of the thickness profile and corresponding flatness of the rolled strip. Accurate methods of predicting the strip thickness profile and strip flatness are important in rolling mill design, rolling schedule set-up, control of mill flatness actuators, and optimization of ground roll profiles. The corresponding dynamic deflection model enables solution of the standard eigenvalue problem to determine natural frequencies and modes of vibration. The presented method for solving the roll-stack deflection problem offers several important advantages over traditional methods. In particular, it includes continuity of elastic foundations, non-iterative solution when using pre-determined elastic foundation moduli, continuous third-order displacement fields, simple stress-field determination, the ability to calculate dynamic characteristics, and a comparatively faster solution time. Consistent with the most advanced existing methods, the presented method accommodates loading conditions that represent roll crowning, roll bending, roll shifting, and roll crossing mechanisms. Validation of the static model is provided by comparing results and solution time with large-scale, commercial finite element simulations. In addition to examples with the common 4-high vertical stand rolling mill, application of the presented method to the most complex of rolling mill configurations is demonstrated

  17. The grinding behavior of ground copper powder for Cu/CNT nanocomposite fabrication by using the dry grinding process with a high-speed planetary ball mill

    Science.gov (United States)

    Choi, Heekyu; Bor, Amgalan; Sakuragi, Shiori; Lee, Jehyun; Lim, Hyung-Tae

    2016-01-01

    The behavior of ground copper powder for copper-carbon nanotube (copper-CNT) nanocomposite fabrication during high-speed planetary ball milling was investigated because the study of the behavior characteristics of copper powder has recently gained scientific interest. Also, studies of Cu/CNT composites have widely been done due to their useful applications to enhanced, advanced nano materials and components, which would significantly improve the properties of new mechatronics-integrated materials and components. This study varied experimental conditions such as the rotation speed and the grinding time with and without CNTs, and the particle size distribution, median diameter, crystal structure and size, and particle morphology were monitored for a given grinding time. We observed that pure copper powders agglomerated and that the morphology changed with changing rotation speed. The particle agglomerations were observed with maximum experiment conditions (700 rpm, 60 min) in this study of the grinding process for mechanical alloys in the case of pure copper powders because the grinding behavior of Cu/CNT agglomerations was affected by the addition of CNTs. Indeed, the powder morphology and the crystal size of the composite powder could be changed by increasing the grinding time and the rotation speed.

  18. Simulation of rolling friction in the working stands of wide-strip mills

    Science.gov (United States)

    Garber, E. A.; Samarin, S. N.; Traino, A. I.; Ermilov, V. V.

    2007-04-01

    The energy consumed for rolling friction in the interroll contact area in the working stands of cold-rolling and pinch-pass mils intended for the production of wide steel strips has been analyzed. The coefficients and power of rolling friction are obtained for the first time using the databases of the process control systems of operating mills and simulating these quantities. A statistically reliable regression relation is obtained between the coefficient of rolling friction and the significant parameters of rolling and skin rolling (i.e., the interroll force, the roll speed, and the roll body roughness). The power fraction consumed for rolling friction is found to reach 60 80% of the total power of the main drive of working stands for skin rolling and 30 50% for cold rolling. Therefore, it is necessary to take into account these power losses in designing mills and developing technological cold-rolling conditions.

  19. Robust shape control in a sendzimir cold-rolling steel mill

    NARCIS (Netherlands)

    Bates, D.G.; Ringwood, J.V.; Holohan, A.M.

    1997-01-01

    The shape control problem for a Sendzimir 20-roll cold rolling steel mill is characterised by operation over a wide range of conditions arising from roll changes, changes in rolling schedules and changes in material gauge, width and hardness. Previous approaches to the problem suggest storing a larg

  20. a Numerical Simulation of Strip Profile in a 6-HIGH Cold Rolling Mill

    Science.gov (United States)

    Du, Xiaozhong; Yang, Quan; Lu, Cheng; Tieu, Anh Kiet; Kim, Shinil

    Shape control is always a key issue in the six-high rolling mill, in which the shifting of the intermediate roll and the work roll have been used to enhance the shape control capability. In this paper, a finite element method (FEM) model has been developed to simultaneously simulate the strip deformation and the roll stack deformation for the six-high rolling mill. The effects of the work-roll bending, the shifting of the intermediate roll and the work roll on the strip crown and edge drop are discussed in details. Results have shown that both higher bending force and more roll shifting will significantly reduce the strip crown. The edge drop is also reduced with the bending force and the roll shifting.

  1. Control Strategies of Asymmetric Strip Shape in Six-High Cold Rolling Mill%Control Strategies of Asymmetric Strip Shape in Six-High Cold Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yun; YANG Quan; WANG Xiao-chen

    2011-01-01

    It is a complicated problem for cold-rolled strip to improve asymmetric strip shape in strip production. A roll system and strip coupled model of six-high cold rolling mill was established with finite element method to estimate the effect of intermediate roll shifting, tilting, symmetric and asymmetric bending technologies on strip profile. To reduce asymmetric defects of strip shape as much as possible, some control strategies were proposed, including tilting and asymmetric bending of intermediate roll and work roll. The combinations of these three control strategies can effectively eliminate asymmetric strip shape defects. Finally, the closed-loop control model of asymmetric flat- ness at the last stand was given, and the flatness control system with the function of asymmetric strip shape control was also designed for cold tandem mill.

  2. Use of a finite element method to calculate roll profiles for broad-strip mills

    Science.gov (United States)

    Garber, E. A.; Bolobanova, N. L.; Traino, A. I.

    2012-05-01

    A model is proposed to calculate the polishing profiling of rolls in broad-strip mills using a finite element method, and it is applied to develop new roll profiles. The finite element method is used to determine the polishing profiling of a roll with a complex shape, which substantially decreases the nonuniformity of reduction and drawing over the strip width. This profiling can be executed on numerical control roll grinders.

  3. Online Load Operating Mode of Oil Film Bearing in High Speed Wire Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    LI Yugui; PANG Siqing; HUANG Qingxue; WANG Jianmei; ZHAO Chunjiang

    2006-01-01

    To study the mechanism of burnt damage of oil film bearing in high-speed wire rolling mill, reasonable temperature sensors are designed and calibrated, pressure block of rolling mill has been transformed into pressure sensors. Online temperature and load of oil film bearing in a domestic precision rolling F15 have been tested. Consequently, a large sum of valuable test data was obtained. The distributions rules of pressure and temperature under continuous online rolling state are recorded in detail. Theoretical and experimental results are beneficial to damage mechanism of oil film bearing, thus its service life could be prolonged. Moreover, such results could provide an important reference for online test and control.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  5. TANDEM COLD MILL PROCESS STABILITY IMPROVEMENT WITH CHROME PLATED WORK ROLLS APPLICATION

    Directory of Open Access Journals (Sweden)

    Sergio Luiz Muratori

    2012-09-01

    Full Text Available The stability of a tandem cold mill is essential to assure the thickness control, the main attribute of cold rolled steel sheets. This stability can be defined as the capability to control the process variables that act direct at the thickness. Among the most important variables are the first stand (mill linear speed and the sheet speed at the interstice ahead of it. This work shows how the chrome plated work rolls application improved this speed control and consequently the stability, which enabled an increase in the work roll rolling campaign (rolling sequence program in such a way significantly higher, compared to when using a non chrome plated work rolls. As results, significantly improvements of work rolls campaigns and the consequent increase of the equipment availability are presented.

  6. Remote Monitoring and Diagnosis System for High-speed Wire Rolling Mills

    Institute of Scientific and Technical Information of China (English)

    CUI Lingli; ZHANG Jianyu; DING Fang; GAO Lixin; WANG Dapeng

    2006-01-01

    Traditional fault diagnosis systems of rolling mills mostly use single machine monitoring net, which leads the real-time data running only in the enterprise locally and can not monitor and manage the high-speed wire rolling mills between units, workshops and factories concentratedly. A new-type structure of remote diagnosis system for high-speed wire rolling mills is presented in this paper. The signal processing, computer network and remote diagnosis etc techniques are used to predictive maintenance manage the rolling mills units in this system. The new structure reinforced the remote feedback function, made up the existing fault diagnosis systems' insufficiency in the extension and the function, promoted resource sharing and avoided the repeat development. The remote diagnosis example shows that the system can monitor and diagnose the fault information of remote machine timely and effectively.

  7. Modeling and Extended State Observer Based Dynamic Surface Control for Cold Rolling Mill System

    Directory of Open Access Journals (Sweden)

    Xu Li

    2016-01-01

    Full Text Available The modeling and control problems are investigated for cold rolling mill system. Firstly, we establish a monitor automatic gauge control (MAGC model for a practical cold rolling mill system. The new model is with mismatched uncertainties. Then, an extended state observer (ESO is developed to estimate uncertainties. In the general high-order systems, the ESO is also used to estimate states. By dynamic surface control method, we design the controller to guarantee stabilization of the cold rolling mill system. Furthermore, we extend proposed method to general high-order systems, in which we analyze the difference from cold rolling mill system. Finally, simulation results for MAGC system are presented to demonstrate the effectiveness of the proposed control strategy.

  8. Comprehensive contour prediction model of work rolls in hot wide strip mill

    Institute of Scientific and Technical Information of China (English)

    Xiaodong Wang; Quan Yang; Anrui He; Renzhong Wang

    2007-01-01

    The predictive calculation of comprehensive contour of work rolls in the on-line strip shape control model during hot rolling consists of two important parts of wear contour calculation and thermal contour calculation, which have a direct influence on the accuracy of shape control. A statistical wear model and a finite difference thermal contour model of work rolls were described. The comprehensive contour is the equivalence treatment of the sum of grinding, wear, and thermal contours. This comprehensive contour calculation model has been applied successfully in the real on-line strip shape control model. Its high precision has been proved through the large amounts of actual roll profile measurements and theoretical analyses. The hit rates (percent of shape index satisfying requirement) of crown and head flatness of the strips rolled, by using the shape control model, which includes the comprehensive contour calculation model, have about 16% and 10% increase respectively, compared to those of strips rolled by using manual operation.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. INVESTIGATION OF THE MAINTENANCE ORGANISATION FOR HOT ROLLING MILLS

    Directory of Open Access Journals (Sweden)

    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 .

  12. Identification and optimization for hydraulic roll gap control in strip rolling mill

    Institute of Scientific and Technical Information of China (English)

    孙杰; 陈树宗; 韩欢欢; 陈兴华; 陈秋捷; 张殿华

    2015-01-01

    In order to improve the control performance of strip rolling mill, theoretical model of the hydraulic gap control (HGC) system was established. HGC system offline identification scheme was designed for a tandem cold strip mill, the system model parameters were identified by ARX model, and the identified model was verified. Taking the offline identified parameters as the initial values, online identification using recursive least square was carried out with model parameters changing. For the purpose of improving system robustness and decreasing the sensitivity due to model errors, the HGC system based on generalized predictive control (GPC) was designed, and simulation experiments for traditional controller and GPC controller were conducted. The results show that both controllers acquire good control effect with model matching. When the model mismatches, for the traditional controller, the overshot will increase to 76.7% and the rising time will increase to 165.7 ms, which cannot be accepted by HGC system; for the GPC controller, the overshot is less than 8.5%, and the rising time is less than 26 ms in any case.

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

    Science.gov (United States)

    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

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

    International Nuclear Information System (INIS)

    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

  15. Optimization of Holding Temperature and Holding Thickness for Controlled Rolling on Plate Mill

    Institute of Scientific and Technical Information of China (English)

    HU Xian-lei; ZHAO Zhong; WANG Jun; WANG Zhao-dong; LIU Xiang-hua; WANG Guo-dong

    2006-01-01

    Holding temperature and holding thickness are main parameters for two-phase controlled rolling on plate mill. The optimization of holding temperature and holding thickness for pass schedule calculation of two-phase controlled rolling on plate mill was presented and its feature is as follows: (1) Determination of holding thickness can be automatically obtained based on the influence of mill safety limits, tracking zone length and holding time on holding thickness; (2) Determination of holding temperature can be automatically obtained and the holding time can be reduced as much as possible; (3) Algorithm can modify the holding temperature and thickness depending on slab size and product size.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    International Nuclear Information System (INIS)

    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

  18. Roll wear on finishing trains of ASP1700 hot strip mills

    Institute of Scientific and Technical Information of China (English)

    Zhimin Xi; Anrui He; Quan Yang; Xiaoxia Lai; Haodong Huang; Lin Zhao

    2004-01-01

    A great deal of research and practical production indicated that a perfect shape control system needs a precise prediction model of roll wear. According to the practical wear curve of work roll in Angang ASP1700 hot strip mill, which was measured by a roll-profilemeter, the model of wear curve caused by one single strip was established. The prediction of work-roll wear was achieved by combining Fortran language and practical technology parameters. The calculated results agreed well with the measured.

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

    Institute of Scientific and Technical Information of China (English)

    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

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

    International Nuclear Information System (INIS)

    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

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

    OpenAIRE

    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...

  2. Soil Contamination with Heavy Metals around Jinja Steel Rolling Mills in Jinja Municipality, Uganda

    Directory of Open Access Journals (Sweden)

    Noel Namuhani

    2015-01-01

    Conclusions. The concentration levels of heavy metals around the steel rolling mills did not appear to be of serious concern, except for copper and cadmium, which showed moderate pollution and moderate to strong pollution, respectively. All heavy metals were within the limits of the United States Environmental Protection Agency (USEPA residential soil standards and the Dutch intervention soil standards. Overall, soils around the Jinja steel rolling mills were slightly polluted with heavy metals, and measures therefore need to be taken to prevent further soil contamination with heavy metals.

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

    Science.gov (United States)

    Moussaoui, A. K.; Abbassi, H. A.; Bouazza, S.

    2008-06-01

    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.

  4. Design of Fault Diagnosis Observer for HAGC System on Strip Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    DONG Min; LIU Cai

    2006-01-01

    By building mathematical model for HAGC (hydraulic automation gauge control) system of strip rolling mill, treating faults as unknown inputs induced by model uncertainty, and analyzing fault direction, an unknown input fault diagnosis observer group was designed. Fault detection and isolation were realized through making observer residuals robust to specific faults but sensitive to other faults. Sufficient existence conditions and design of the observers were given in detail. Diagnosis observer parameters for servo valve, cylinder, roller and body rolling mill were obtained respectively. The effectiveness of this diagnosis method was proved by actual data simulations.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  6. KDD-based rolling schedule model for plate mill

    Institute of Scientific and Technical Information of China (English)

    Zhichun Mu; Dangxian Ma; Shaobo Wang; Changsong Wang

    2005-01-01

    A novel method for generating a rolling schedule is presented, which is fundamentally different from the existing ones.KDD (knowledge discovery in database) techniques are applied for discovering association rules between rolling parameters in a large database of rolling operation, and based on these rules, the schedule for the crucial last six finishing passes is generated. Operational evaluation shows that the schedule generated by the new method outperforms that generated by existing methods. It also shows how in this application the human's domain knowledge is applied to speed up the KDD process and to ensure the validity of the knowledge discovered.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  8. Force prediction in cold rolling mills by polynomial methods

    Directory of Open Access Journals (Sweden)

    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.

  9. Fuzzy-Neural Control of Hot-Rolling Mill

    OpenAIRE

    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 ...

  10. Control Method for Steel Strip Roughness in Two-stand Temper Mill Rolling

    Institute of Scientific and Technical Information of China (English)

    LI Rui; ZHANG Qingdong; ZHANG Xiaofeng; YU Meng; WANG Bo

    2015-01-01

    How to control surface roughness of steel strip in a narrow range for a long time has become an important question because surface roughness would significantly influence the appearance of the products. However, there are few effective solutions to solve the problem currently. In this paper, considering both asperities of work roll pressing in and squeezing the steel strip, two asperity contact models including squeezing model and pressing in model in a two-stand temper mill rolling are established by using finite element method (FEM). The simulation investigates the influences of multiple process parameters, such as work roll surface roughness, roll radius and roll force on the surface roughness of steel strip. The simulation results indicate that work rolls surface roughness and roll force play important roles in the products;furthermore, the effect of roll force in the first stand is opposite to the second. According to the analysis, a control method for steel strip surface roughness in a narrow range for a long time is proposed, which applies higher work roll roughness in the first stand and lower roll roughness in the second to make the steel strip roughness in a required narrow range. In the later stage of the production, decreasing the roll force in the first stand and increasing the roll force in the second stand guarantee the steel strip roughness relatively stable in a long time. The following experimental measurements on the surface topography and roughness of the steel strips during the whole process are also conducted. The results validate the simulation conclusions and prove the effect of the control method. The application of the proposed method in the steel strip production shows excellent performance including long service life of work roll and high finished product rate.

  11. Control method for steel strip roughness in Two-stand temper mill rolling

    Science.gov (United States)

    Li, Rui; Zhang, Qingdong; Zhang, Xiaofeng; Yu, Meng; Wang, Bo

    2015-05-01

    How to control surface roughness of steel strip in a narrow range for a long time has become an important question because surface roughness would significantly influence the appearance of the products. However, there are few effective solutions to solve the problem currently. In this paper, considering both asperities of work roll pressing in and squeezing the steel strip, two asperity contact models including squeezing model and pressing in model in a two-stand temper mill rolling are established by using finite element method (FEM). The simulation investigates the influences of multiple process parameters, such as work roll surface roughness, roll radius and roll force on the surface roughness of steel strip. The simulation results indicate that work rolls surface roughness and roll force play important roles in the products; furthermore, the effect of roll force in the first stand is opposite to the second. According to the analysis, a control method for steel strip surface roughness in a narrow range for a long time is proposed, which applies higher work roll roughness in the first stand and lower roll roughness in the second to make the steel strip roughness in a required narrow range. In the later stage of the production, decreasing the roll force in the first stand and increasing the roll force in the second stand guarantee the steel strip roughness relatively stable in a long time. The following experimental measurements on the surface topography and roughness of the steel strips during the whole process are also conducted. The results validate the simulation conclusions and prove the effect of the control method. The application of the proposed method in the steel strip production shows excellent performance including long service life of work roll and high finished product rate.

  12. Coupled dynamic modeling of rolls model and metal model for four high mill based on strip crown control

    Science.gov (United States)

    Sun, Jianliang; Peng, Yan; Liu, Hongmin

    2013-01-01

    The crown is a key quality index of strip and plate, the rolling mill system is a complex nonlinear system, the strip qualities are directly affected by the dynamic characteristics of the rolling mil. At present, the studies about the dynamic modeling of the rolling mill system mainly focus on the dynamic simulation for the strip thickness control system, the dynamic characteristics of the strip along the width direction and that of the rolls along axial direction are not considered. In order to study the dynamic changes of strip crown in the rolling process, the dynamic simulation model based on strip crown control is established. The work roll and backup roll are considered as elastic continuous bodies and the work roll and backup roll are joined by a Winkler elastic layer. The rolls are considered as double freely supported beams. The change rate of roll gap is taken into consideration in the metal deformation, based on the principle of dynamic conservation of material flow, the two dimensional dynamic model of metal is established. The model of metal deformation provides exciting force for the rolls dynamic model, and the rolls dynamic model and metal deformation model couple together. Then, based on the two models, the dynamic model of rolling mill system based on strip crown control is established. The Newmark-β method is used to solve the problem, and the dynamic changes of these parameters are obtained as follows: (1) The bending of work roll and backup roll changes with time; (2) The strip crown changes with time; (3) The distribution of rolling force changes with time. Take some cold tandem rolling mill as subject investigated, simulation results and the comparisons with experimental results show that the dynamic model built is rational and correct. The proposed research provides effective theory for optimization of device and technological parameters and development of new technology, plays an important role to improve the strip control precision and

  13. Fuzzy-Neural Control of Hot-Rolling Mill

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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.

  16. Identification of Material Properties Based on Rolling Process at 4-Stand Laboratory Mill

    Science.gov (United States)

    Szeliga, D.; Graf, M.; Kawalla, R.; Pietrzyk, M.

    2011-05-01

    The general objective of the work is to estimate the properties of the material in hot strip rolling process. The authors propose a modified inverse algorithm; to make direct use of the manufacturing process instead of conventional plastometric tests. This approach allows to reduce time and costs of identification. The rolling at 4-stand pilot mill at the Institute of Metal Forming, TU Bergakademie, Freiberg was selected. The material was C45 steel. The measured quantities of the process were rolling loads and torques, as well as temperatures. Numerical tests have shown that accuracy of torque predictions is low, therefore, the goal function of inverse analysis was defined as an average square root error between measured and FEM calculated rolling loads only. The first stage of the work was to develop the model of the hot strip rolling, which defines the direct model in the inverse analysis. This model is complex, it composes the whole roughing and finishing rolling. Based on the model and results of the laboratory experiment, the deformation process including the temperature field and the recrystallization up to the last finishing mill is calculated. Moreover, an application of the inverse analysis to the identification of the models of the hot strip rolling and design of the rolling parameters allows to obtain the required microstructure of final products. Inverse analysis and/or optimization of such a manufacturing chain is time-consuming. Large number of control parameters makes the time of the analysis unacceptable. Therefore, the metamodel of the hot rolling is applied to make the inverse calculations efficient. In the work the results of calculations with identified process parameters and experimental data are compared and presented. Also advantages and disadvantages are described.

  17. Work roll thermal contour prediction model of nonoriented electrical steel sheets in hot strip mills

    Institute of Scientific and Technical Information of China (English)

    Ningtao Zhao; Jianguo Cao; Jie Zhang; Yi Su; Tanli Yan; Kefeng Rao

    2008-01-01

    The demands for profile and flatness of nonoriented electrical steels are becoming more and more severe. The temperature field and thermal contour of work rolls are the key factors that affect the profile and flatness control in the finishing trains of the hot rolling. A theoretic mathematical model was built by a two-dimensional finite difference to calculate the temperature field and thermal contour at any time within the entire rolling campaign in the hot rolling process. To improve the calculating speed and precision,some special solutions were introduced, including the development of this model, the simplification of boundary conditions, the computation of heat transfer coefficient, and the narrower mesh along the edge of the strip. The effects of rolling pace and work roll shifting on the temperature field and thermal contour of work rolls in the hot rolling process were demonstrated. The calculated results of the prediction model are in good agreement with the measured ones and can be applied to guiding profde and flatness control of nonoriented electrical steel sheets in hot strip mills.

  18. Lubricant for clean rolling: Escapee oil particles keep cold rolling steel mills lubricated

    NARCIS (Netherlands)

    Van De Graaf, A.

    2002-01-01

    One of the unique selling points of the Corus steel mills at IJmuiden is the quality of the steel they produce. The lubrication used during the last production stage is one of the factors that determine how clean and smooth the steel will emerge from the mill. The usual lubricant consists of an emul

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

    Institute of Scientific and Technical Information of China (English)

    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.

  20. Influence of a matrix on properties of mottled cast iron applied for mill rolls

    Directory of Open Access Journals (Sweden)

    J. Krawczyk

    2010-07-01

    Full Text Available Mill rolls are ones of the most expensive tools applied in plastic working processes and have to satisfy several criteria, which allow them to be used. Cast iron mill rolls, due to their fracture toughness and tribological properties, are the most often applied at hot-rolling in the last rolling stands. This results from the smallest dynamic loads of such rolling stands and the decisive influence of the surface quality of these tools on the surface quality of the rolled product. An improper microstructure of rolls can lead to their premature wearing, e.g. broken flanges, pivots twisting off etc. By means of the heat treatment the matrix microstructure and morphology of carbide precipitationscan be modified and this in-turn can influence cast iron properties.Determination of the influence of microstructure changes, caused by the heat treatment, on the properties of EN-GJN-HV300 low-alloycast iron, after its modification and spheroidization – is the aim of the present paper. Those changes are based on the formation pearlitic or bainitic matrices at the similar morphology of graphite and ledeburitic cementite precipitations. The performed investigations should enable designing the heat treatment of cast iron metallurgical rolls in such a way as to obtain the optimal microstructures for functional parameters of these type of tools. The influence of changing the pearlitic matrix into the bainitic one on such properties as: hardness, impact strength, tensile strength, creep limit, bending strength and a stress intensity factor KIc was investigated in this study. Samples for testing, the listed above mechanical properties, were taken from an industrial casting with care to have pieces of very similar crystallization conditions.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. Regulation of the Heating Furnace in Tube Rolling Mill

    Directory of Open Access Journals (Sweden)

    Kostúr, K.

    2006-01-01

    Full Text Available The rolling of tube requires homogeneous heating along the tube. In steel work the difference along tube was sometimes 80 °C. The reasons for bad homogeneousness of heating were analyzed by a simulation model of heating furnace. Then the proposal was made for a new control system and also the proposal for reconstruction of furnace. In this contribution also a description of some ways for improvement of heating was made. The main contribution is the proposal of an adaptive system

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  6. Preparation Model Based Control System For Hot Steel Strip Rolling Mill Stands

    Science.gov (United States)

    Bouazza, S. E.; Abbassi, H. A.; Moussaoui, A. K.

    2008-06-01

    As part of a research project on El-hadjar Hot Steel Rolling Mill Plant Annaba Algeria a new Model based control system is suggested to improve the performance of the hot strip rolling mill process. In this paper off-line model based controllers and a process simulator are described. The process models are based on the laws of physics. these models can predict the future behavior and the stability of the controlled process very reliably. The control scheme consists of a control algorithm. This Model based Control system is evaluated on a simulation model that represents accurately the dynamic of the process. Finally the usefulness to the Steel Industry of the suggested method is highlighted.

  7. Reduced-order observer-based robust synchronisation control of cold rolling mills with measurement delay

    Science.gov (United States)

    Jiao, Xiaohong; Mei, Zhisong

    2010-10-01

    To improve the quality of strip thickness, synchronisation control is investigated for cold rolling mills driven by dual-cylinder electro-hydraulic servo systems. Realising synchronised control in hydraulic automatic gauge control (HAGC) systems of cold rolling mills has challenges with not only the inherent nonlinearities of hydraulic servo systems and uncertainties of load variation but also measurement delay of strip thickness. Since all states are not measurable in practice, output feedback robust synchronisation control problem should be addressed for uncertain nonlinear systems with output delay. Thus, a reduced-order observer-based robust synchronous controller is presented by employing Lyapunov functional stability theory. The controller designed by incorporating the integral of the position synchronisation error of two pistons into state variables successfully guarantees asymptotic convergence to zero of both tracking errors and synchronisation error simultaneously regardless of the nonlinearities and uncertainties as well as the measurement delay. Simulation results in a model obtained from a real cold strip rolling mill demonstrate the effectiveness of the approach.

  8. A vision-based material tracking system for heavy plate rolling mills

    Science.gov (United States)

    Tratnig, Mark; Reisinger, Johann; Hlobil, Helmut

    2007-01-01

    A modern heavy plate rolling mill can process more than 20 slabs and plates simultaneously. To avoid material confusions during a compact occupancy and the permanent discharging and re-entering of parts, one must know the identity and position of each part at every moment. One possibility to determine the identity and position of each slab and plate is the application of a comprehensive visual-based tracking system. Compared to a tracking system that calculates the position of a plate based on the diameter and the turns of the transport rolls, a visual system is not corrupted by a position- and material dependent transmission slip. In this paper we therefore present a vision-based material tracking system for the 2-dimensional tracking of glowing material in harsh environment. It covers the production area from the plant's descaler to the pre-stand of the rolling mill and consists of four independent, synchronized overlapping cameras. The paper first presents the conceptual design of the tracking system - and continues then with the camera calibration, the determination of pixel contours, the data segmentation and the fitting & modelling of the objects bodies. In a next step, the work will then show the testing setup. It will be described how the material tracking system was implemented into the control system of the rolling mill and how the delivered tracking data was checked on its correctness. Finally, the paper presents some results. It will be shown that the position of some moving plates was estimated with a precision of approx. 0.5m. The results will be analyzed and it will be explained where the inaccuracies come from and how they eventually can be removed. The paper ends with a conclusion and an outlook on future work.

  9. 轧辊轴向移动轧机的应用与发展%APPLICATION AND DEVELOPMENT OF ROLLING MILL WITH AXIAL SHIFTING ROLL

    Institute of Scientific and Technical Information of China (English)

    张凤泉

    2001-01-01

    介绍了轧辊轴向移动轧机的发展过程、工作原理、形式特点以及在国内的应用情况,分析了目前应用最普遍的HC系列轧机的板形控制特性,并对辊系配置进行了深入的探讨。%The present paper introduces the history of development, operating principle and characteristics of the rolling mill with axial shifting roll as well as its application in the Country, analyzes the feature of the shape control for the currently most broadly applied HC rolling mill and discusses in detail the setting up of the roll system.

  10. Effect of the grinding behaviour of coal blends on coal utilisation for combustion

    OpenAIRE

    Rubiera González, Fernando; Arenillas de la Puente, Ana; Fuente Alonso, Enrique; N. Miles; Pis Martínez, José Juan

    1999-01-01

    Grinding of a high volatile bituminous coal was performed in three comminution devices: Raymond Mill (RM), Rolls Crusher (RC) and Ball Mill (BM). The pulverised samples were sieved to obtain four particle size fractions, and temperature-programmed combustion (TPC) was used for the evaluation of their combustion behaviour. In addition, three coals of different hardness and rank were mixed in various proportions in order to compare the combustibility characteristics of the binary coal blends wi...

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

    International Nuclear Information System (INIS)

    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

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

    Institute of Scientific and Technical Information of China (English)

    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.

  13. Plate Rolling Modeling at Mill 5000 of OJSC ``Magnitogorsk Iron and Steel'' for Analysis and Optimization of Temperature Rates

    Science.gov (United States)

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

    2010-06-01

    Modeling of strip deflected mode and thermal state in rolling is an integral part of the technology and perspective rolling-mill machinery such as plate mill 5000 of the OJSC "Magnitogorsk Iron and Steel". To comprehend metal behavior in the deformation zone in the rough passes during plate rolling it is essential to assess the impact of various temperature factors on variations in field of stress and strain intensities as well as temperature fields in deformation. To do such researches in consideration of various software products and adequate results one of the most effective methods nowadays is regarded as the method of finite elements. The research shows modeling of roughing rolling of a pipe steel sheet with strength category X80 according to standard API-5L. In the research of the metal deflected mode software product DEFORM 2D has been used for the isothermal and nonisothermic process. The mathematical modeling allows revealing the impact of temperature field on the metal deflected mode in the rough passes in plate rolling. Supposedly, it is deformation heating that can have more impact on the ingot temperature profile in the finishing passes in controlled rolling of the pipe steel grades. It is defined by high percent reduction, rolling speeds; more area of heat exchange surface; less thickness and lower temperature of rolling. The results can be used to develop efficient modes of plate rolling of the pipe steels.

  14. Validation of a 3-D, Thermo-Mechanically Coupled Model for Multi-Pass Rolling in a Reversing Mill

    Energy Technology Data Exchange (ETDEWEB)

    Rhee, M; Wang, P; Li, M; Becker, R

    2004-01-30

    A three dimensional numerical model simulating multi-pass, hot rolling on a reversing mill has been developed to analyze deformation patterns and shape changes of a rolled ingot. Validation simulations through 15 passes with an 86% reduction have been performed using the thermo-mechanically coupled model to track the evolution of the deformed ingot geometry. The heat transfer coefficient for thermal conduction between the rolls and slab has been estimated in accordance with experimental data, and heat transfer to the air and coolant outside of the roll bite is included. A hyperbolic sine model using the Zener-Hollomon parameter is used to capture the temperature and strain rate dependence of the aluminum alloy. A Coulomb friction model with a flow strength dependent maximum limit on the interfacial shear stress was employed between the rolls and ingot. Results of validation simulations and comparisons with experiments focusing on the ingot shape evolution are discussed.

  15. Bearing restoration by grinding

    Science.gov (United States)

    Hanau, H.; Parker, R. J.; Zaretsky, E. V.; Chen, S. M.; Bull, H. L.

    1976-01-01

    A joint program was undertaken by the NASA Lewis Research Center and the Army Aviation Systems Command to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. No bearing failures occurred related to the restoration by grinding process. The risk and cost of a bearing restoration by grinding programs was analyzed. A microeconomic impact analysis was performed.

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

    Science.gov (United States)

    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.

  17. 轧钢机厚度鲁棒控制策略研究%Robust Control Strategy Rolling Mill Thickness

    Institute of Scientific and Technical Information of China (English)

    罗建强

    2015-01-01

    One of the important indicators of the quality of products for the strip thickness. In order to improve the quality of strip products, the need to strengthen the study of rolling mill thickness control system. Discusses the robust control strategy rolling mill thickness, elaborated robust control theory, and describes the rolling mill thickness control based on the robust performance analysis of the rolling mill thickness robust control strategies, hoping to provide reference and research areas relevant reference.%衡量板带产品质量的重要指标之一为厚度。为了提高板带产品的质量,需要加强对轧钢机厚度控制系统的研究。主要讨论了轧钢机厚度鲁棒控制策略,阐述了鲁棒控制理论,说明了轧钢机厚度控制基础,从鲁棒性能方面分析了轧钢机厚度鲁棒控制策略,希望能为相关研究领域提供借鉴和参考。

  18. Comparison of pretreating pyrite cinder by high pressure roller grinding with damp milling to improve pelletization%高压辊磨和润磨预处理强化硫酸渣球团对比研究

    Institute of Scientific and Technical Information of China (English)

    朱德庆; 陈栋; 潘建

    2011-01-01

    The pretreatment of pyrite cinder was studied using high pressure roll grinding (HPRG), which aims to improve the quality of green pellets and reinforce roasting performance of pyrite cinder pellets, and HPRG was compared with damp milling was made. The results show that both HPRG and damp milling can significantly improve green ball quality while bentonite consumption is dramatically reduced, the drop number of green balls increases from 9.0 times without pretreatment to more than 30.0 times from 0.5 m height by pretreating the pyrite cinder using HPRG and 27.4 times from 0.5 m height by using damp milling, the compressive strength increases from 7.2 N per pellet without pretreatment to 10.6 N per pellet by using HPGR to pretreat cinder and 13.7 N per pellet by using damp milling, respectively. Thermal shock temperature of green balls is above 540 ℃ and the moisture of green pellets drops by 6.5%. After the pyrite cider is pretreated by HPRG and damp milling, the preheating and roasting temperatures of the pyrite cinder pellets are decreased by 150 ℃ and 80 ℃, respectively, and the roasting time is shortened by 6 mines. Therefore, the roasting performance of pyrite cinder pellets is reinforced greatly by HPRG and damp milling. The mechanisms of HPRG and damp milling show that specific surface areas and surface energy and activity are improved, and that solid diffusion reactions are enhanced, resulting in strong bonding inside fired pellets. However, productivity of HPRG is much higher than that of damp milling, and unit energy consumption is lower than that of damp milling.%采用高压辊磨技术预处理硫酸渣改善生球质量和强化球团焙烧,并且与传统的润磨技术进行对比.研究结果表明:高压辊磨和润磨预处理硫酸渣均可大幅度提高生球质量,在膨润土用量大幅降低的同时,生球落下强度从9 0次/(0.5 m)分别增加到大于30.0次/(0.5 m)和27.4次/(0.5 m),抗压强度从7.2 N/个分别增加到10

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

    International Nuclear Information System (INIS)

    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

  20. Modelling and Simulation of Three Level Inverters for Main Drive of the Plate Mill Rolling Stand

    Directory of Open Access Journals (Sweden)

    Gasiyarov Vadim R.

    2016-01-01

    Full Text Available This paper addresses a modelling and a simulation of three level inverters for main drive of the plate mill rolling stand. The main purpose of the article is to develop of a mathematical description of the three level voltage source inverter based on a space vector pulse width modulation and to simulate a consumption current by the main electric drive based on 18-pulse rectification circuit. A twelve-megawatt synchronous motor as a load has been used. The modelling results were simulated at the Matlab/Simulink program. It can allow us to estimate an electromagnetic compatibility of the main electric drive based on transients of the consumption current. The research results can be used to assess the electromagnetic compatibility of powerful three level natural point clamped converters with different types of the space vector pulse width modulation on a load or a grid.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  2. Multicriteria FMECA Based Decision-Making for Aluminium Wire Process Rolling Mill through COPRAS-G

    Directory of Open Access Journals (Sweden)

    Nilesh Pancholi

    2016-01-01

    Full Text Available This paper presents a multifactor decision-making approach based on “grey-complex proportional assessment (COPRAS-G method” in a view to overcome the limitations of Failure Mode Effect and Criticality Analysis (FMECA. In this model, the scores against each failure mode are expressed in grey number instead of crisp values to evaluate the criticalities of the failure modes without uncertainty. The suggested study is carried out to identify the weights of major failure causes for bearings, gears, and shafts of aluminium wire rolling mill plant. The primary findings of the paper are that sudden impact on the rolls seems to be most critical failure cause and loss of power seems to be least critical failure cause. It is suggested to modify the current control practices with proper maintenance strategy based on achieved maintainability criticality index (MCI for different failure causes. The outcome of study will be helpful in deriving optimized maintenance plan to maximize the performance of process industry.

  3. Increase of mechanical properties of hot plate due to introduction of a cycle of high-speed asymetry of work rolls on four-high mill 5000

    Institute of Scientific and Technical Information of China (English)

    Severinets; I.; Y.; Kazakbaev; N.; M.; Rusakov; A.; D.; Tyapaev; O.; V.

    2005-01-01

    In the given work results of researches asymmetric rolling on reversive mill 5000 are considered.By definition of boundary modes of asymmetry and an opportunity of application results of precomputations are resulted in production for various circuits of rolling. Results of influence of asymmetric rolling on physic and mechanical properties, structure and geometry hot sheets are shown, recommendations to introduction of modes of asymmetry in a production cycle of manufacturing of sheet-rolling production of the improved quality are developed

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

    Institute of Scientific and Technical Information of China (English)

    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.

  5. Steel balls forming by cross rolling with upsetting

    Directory of Open Access Journals (Sweden)

    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.

  6. Tribological Testing of Anti-Adhesive coatings for Cold Rolling Mill Rolls—Application to TiN-Coated Rolls

    Science.gov (United States)

    Ould, Choumad; Gachon, Yves; Montmitonnet, Pierre; Badiche, Xavier

    2011-05-01

    Roll life is a major issue in cold strip rolling. Roll wear may result either in too low roll roughness, bringing friction below the minimum requested for strip entrainment; or it may degrade strip surface quality. On the contrary, adhesive wear and transfer ("roll coating", "pick up") may form a thick metallic deposits on the roll which increases friction excessively and degrades strip surface again [1]. The roll surface, with the help of a materials-adapted lubricant, must therefore possess anti-wear and anti-adhesive properties. Thus, High Speed Steeel (HSS) rolls show superior properties compared with standard Cr-steel rolls due to their high carbide surface coverage. Another way to improve wear and adhesion properties of surfaces is to apply hard metallic (hard-Cr) or ceramic coatings. Chromium is renowned for its excellent anti-wear and anti-adhesive properties and may serve as a reference. Here, as a first step towards alternative, optimised coatings, a PVD TiN coating has been deposited on tool steels, as previous attempts have proved TiN to be rather successful in cold rolling experiments [2,3]. Different tribological tests are reported here, giving insight in both anti-adhesive properties and fatigue life improvement.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. 冷轧机张力控制系统分析%Cold Rolling Mill Tension Control System Analysis

    Institute of Scientific and Technical Information of China (English)

    吴俊

    2015-01-01

    The stability of tension directly affects the quality of the rolled products, therefore, constant tension control rolling mill automatic control system is a key technology. Expounds the role of tension in mill production, the concept of tension, tension control and influence of the basic principles of tension fluctuation factor.%张力的稳定性直接影响着轧制产品的质量,因此,轧机的恒张力控制是轧机自动控制系统中的关键技术。主要阐述了张力在轧机生产中的作用、张力的概念、张力控制的基本原理和影响张力波动的因素。

  9. EXPERIMENTAL STUDY ON INFLUENCE OF SUPPLIED PRESSURE FLUCTUATION ON OUTPUT ARACTERISTIC OF PRESSURE CONTROL SYSTEM OF ROLLING MILL

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    The infulence of supplied pressure fluctuation on output accuracy for the electro-hydraulic pressure control system of the rolling mill is discussed.Based on the bond graph theory and experimental study,the relationship between the variation of system output pressure and the supplied pressure fluctuation and the influence of the system bandwidth on system output pressure are provided.A theoretical base for determining the allowable fluctuation range of pressure and accurate design of constant pressure source system is obtained.

  10. The Physical Flow of Materials and the Associated Costs in the Production Process of a Rolling Mill

    Directory of Open Access Journals (Sweden)

    Holisz-Burzyńska, J.

    2007-01-01

    Full Text Available Efficiency of resources use is, in a large extent, determined by the organization of production flow and the way of their control. The optimization of materials flow in the production process requires the identification of physical flows of goods and it cost. In the article the physical flow process of materials stream in the production process in one of Polish rolling mill and also its logistics analysis and cost analysis are presented.

  11. 连轧机组换辊控制系统的研究与应用%Study and Application of Roll Change Control System in Cold Tandem Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    王亮

    2013-01-01

      介绍某1420 mm 五机架冷连轧生产线换辊控制系统的结构与控制方式。%The article describes the structure and control mode of the roll change control system for a 1420 mm five-stand cold tandem rolling mill.

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

    OpenAIRE

    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...

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

    Science.gov (United States)

    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

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  16. Synchronous control for the hydraulic width system of edger rolling mill

    Science.gov (United States)

    Ning, Shurong; Fan, Zhuoyu

    2008-10-01

    Edger rolling mill is a load system in which the upper and the lower cylinder actuate a side vertical roller at the same time. Due to the linkage of the load, the output and control of two channels influence each other. Synchronic-control issue is discussed aim to the system with serious coupling. Neural network inverse as decoupling controller is proposed to account for the complicated process dynamics characterized by nonlinear, time-varying, uncertain and load couple properties. Firstly, the reversibility of the system is analyzed and the ANN inverse dynamic is constructed based on a feed forward and neural network structure with enlarged back propagation algorithm. Secondly, the system is changed into two pseudo-linear sub-system through connecting the controlled system and inverse dynamic model in series. Aim to two pseudo-linear sub-system pole assignments method is proposed to enhance the whole system performance. A series simulation was conducted and results showed the proposed controller does better than traditional PID not only on decoupling but also on the transient response, as well as robustness under vary conditions.

  17. 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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2011-01-01

    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

    OpenAIRE

    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

  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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  3. Online Prediction Under Model Uncertainty via Dynamic Model Averaging: Application to a Cold Rolling Mill.

    Science.gov (United States)

    Raftery, Adrian E; Kárný, Miroslav; Ettler, Pavel

    2010-02-01

    We consider the problem of online prediction when it is uncertain what the best prediction model to use is. We develop a method called Dynamic Model Averaging (DMA) in which a state space model for the parameters of each model is combined with a Markov chain model for the correct model. This allows the "correct" model to vary over time. The state space and Markov chain models are both specified in terms of forgetting, leading to a highly parsimonious representation. As a special case, when the model and parameters do not change, DMA is a recursive implementation of standard Bayesian model averaging, which we call recursive model averaging. The method is applied to the problem of predicting the output strip thickness for a cold rolling mill, where the output is measured with a time delay. We found that when only a small number of physically motivated models were considered and one was clearly best, the method quickly converged to the best model, and the cost of model uncertainty was small; indeed DMA performed slightly better than the best physical model. When model uncertainty and the number of models considered were large, our method ensured that the penalty for model uncertainty was small. At the beginning of the process, when control is most difficult, we found that DMA over a large model space led to better predictions than the single best performing physically motivated model. We also applied the method to several simulated examples, and found that it recovered both constant and time-varying regression parameters and model specifications quite well.

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

    Directory of Open Access Journals (Sweden)

    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. 大型塔式磨机在金精矿氰化细磨中的应用%Application of Large Tower Mill in Cyanide Fine Grinding of Gold Concentrate

    Institute of Scientific and Technical Information of China (English)

    姚福善

    2014-01-01

    Tower mill is a type of fine grinding equipment with vertical fixed installation,cylinder fixed and helical mixing device.Because gold and silver particles is fine in gold concentrate,and most of gold and silver minerals with even had body and inclusions form coexist with pyrite,fully grinding of gold concentrate is necessary in order to improve grinding fineness,make gold and silver particles fully naked,and achieve the effect of monomer dissociation.During the process of cyanide gold concentrate,due to the large increase in degree of dissociation,gold and silver are leached thoroughly,thus cyanide recovery.Tower grinding machine has the advantage of low energy consumption,grinding fine granularity,low noise,occupies less space,easy maintenance, easy installation and high grinding efficiency,therefore,it is ideal fine grinding mill in cyanide fine grinding.%塔式磨机是一种垂直安装、筒体固定及内带螺旋搅拌装置的搅拌型细磨设备。由于金精矿中金、银颗粒比较细,金、银矿物大多以连生体和包裹体形式与黄铁矿共存,需要对金精矿进行充分研磨,提高磨矿细度,使金、银颗粒充分裸露,达到单体解离的效果。在金精矿氰化过程中,解离度的大幅提高,可使金、银浸出彻底,氰化回收率随之提高。塔式磨机具有能耗低、磨矿粒度细、噪音低、占用空间少、易维护、便于安装及磨矿效率高等优点,因此是金精矿氰化细磨的理想磨机。

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  8. Effect of hydraulic bending roll on vibration energy of a hot continuous rolling mill%液压弯辊控制参数对热连轧机振动能量影响研究

    Institute of Scientific and Technical Information of China (English)

    闫晓强; 么爱东; 刘克飞

    2016-01-01

    In recent years,hot continuous rolling mill vibration problems are more prominent,many enterprises urgently need to solve this problem.Here,the vibration problem of a hot continuous rolling mill was monitored online. Then,a coupled dynamic model of a rolling mill vertical system and a hydraulic bending roll system was built.According to the actual mill parameters.MATLAB was used to do a simulation study.The effects of the control performance of the hydraulic bending rolls system on the rollers system vibration energy were analyzed by changing the controller parameters of the hydraulic bending roll system.The results provided one of effective measures for suppressing vibrations of hot continuous rolling mills.%近年来,热连轧机振动问题显得更加突出和复杂化,众多企业迫切需要解决这一难题。首先对某热连轧机振动现象进行在线监测;然后依据轧机实际参数建立液压弯辊系统和轧机垂直系统的耦合动力学模型,利用 MATLAB进行了仿真研究,通过改变液压弯辊系统中控制器参数,获得液压弯辊的控制性能对辊系振动能量的影响,实践表明这是有效抑制振动的措施之一。

  9. Key technology of Zhongyue tinplate "twice rolling & once planishing" rolling mill%中粤镀锡基板“两轧一平整”机组关键技术

    Institute of Scientific and Technical Information of China (English)

    黄志锋

    2011-01-01

    The key technologies of six-rollerl 100 mm wide HC reversible cold rolling mill and four-roller 1 100 mm wide planshing mill in TMBP production line are analyzed. The key technologies of six-rollerl 100 mm wide HC reversible cold rolling mill include the thickness control, plate shape control, tention control and unoiling from plate surface. And the key technologies of four-roller 1100 mm wide planshing mill include the selection of planishing mode, tention control and surface cleaning by blowing. The application of " twice rolling & once planishing" rolling mill in the tinplate procuction is described.%分析了中山中粤镀锡基板生产线1100mm六辊可逆冷轧机和1100mm四辊平整机组的关键技术,冷轧机的厚度控制、板型控制、张力控制技术和带材表面除油技术,平整机的平整模式选择、板型控制、张力控制及表面吹扫技术等,以及两轧一平整机组在中山中粤镀锡基板生产中的应用.

  10. Gearbox fault diagnosis of rolling mills using multiwavelet sliding window neighboring coefficient denoising and optimal blind deconvolution

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Fault diagnosis of rolling mills, especially the main drive gearbox, is of great importance to the high quality products and long-term safe operation. However, the useful fault information is usually submerged in heavy background noise under the severe condition. Thereby, a novel method based on multiwavelet sliding window neighboring coefficient denoising and optimal blind deconvolution is proposed for gearbox fault diagnosis in rolling mills. The emerging multiwavelets can seize the important signal processing properties simultaneously. Owing to the multiple scaling and wavelet basis functions, they have the supreme possibility of matching various features. Due to the periodicity of gearbox signals, sliding window is recommended to conduct local threshold denoising, so as to avoid the "overkill" of conventional universal thresholding techniques. Meanwhile, neighboring coefficient denoising, considering the correlation of the coefficients, is introduced to effectively process the noisy signals in every sliding window. Thus, multiwavelet sliding window neighboring coefficient denoising not only can perform excellent fault extraction, but also accords with the essence of gearbox fault features. On the other hand, optimal blind deconvolution is carried out to highlight the denoised features for operators’ easy identification. The filter length is vital for the effective and meaningful results. Hence, the foremost filter length selection based on the kurtosis is discussed in order to full benefits of this technique. The new method is applied to two gearbox fault diagnostic cases of hot strip finishing mills, compared with multiwavelet and scalar wavelet methods with/without optimal blind deconvolution. The results show that it could enhance the ability of fault detection for the main drive gearboxes.

  11. The Research on Optimization of Edge Drop Control for Cold Tandem Rolling Mill

    Science.gov (United States)

    Zhou, Xiao-Min; Yue, Xiao-Xue

    2016-05-01

    The cold tandem rolling of metal strip presents a significant control challenge because of nonlinearities and process complexities. And reducing edge drop of cold rolling strips and meeting uniform thickness will be a new tough shape theories and technologies. In this paper, the existing edge drop control are analyzed and optimized. The simulation results and practical data show that the optimized control system can effectively control the edge drop.

  12. 钢坯试样铣磨床总体方案的创新设计%Innovative design for overall Scheme of milling-grinding machine for billet steel sample

    Institute of Scientific and Technical Information of China (English)

    薛会民; 欧阳晶晖

    2011-01-01

    It expounds the innovative design for overall scheme of the milling-grinding machineAc-cording to the processing requirements of high efficiency and high surface quality for billet test sample,the principle scheme of machine tool was proposed based on combined innovation, which achieves a composite process of milling and grindingJn addition the grinding adopts modern belt grinding.The motion scheme of the machine tool was designed through analyzing movement functionsAs for general structure of the machine tool fixed beam gantry frame structure is adopted based on structural variation.The result indicates that the overall scheme innovation realizes the uniqueness design of the machine tool,which has good performance and can well satisfy the processing requirements of billet steel sample.%阐述了铣磨床总体方案的创新设计,针对钢坯检测试样高效率、高表面质量的加工要求,采用组合创新的方法,提出了在同一机床上实现铣削、磨削复合加工的工艺原理方案,并且机床的磨削加工采用了现代砂带磨削.通过分析机床的各种运动功能,设计了机床的运动方案.对于机床的总体结构布局,采用结构变异的方法,确定其为定梁龙门式框架结构.结果表明,通过总体方案的创新,实现了机床的独特性设计,所设计机床性能优良,很好地满足了钢坯检测试样的加工要求.

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

    International Nuclear Information System (INIS)

    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

  14. Design of Oil Supply Test Platform for High-speed CNC Roll Grinding Machine%高速数控轧辊磨床供油试验平台的设计

    Institute of Scientific and Technical Information of China (English)

    余云流; 吴怀超; 简晓书; 付恒勋; 黄惠生

    2012-01-01

    基于国产传统数控轧辊磨床的现有技术,分别设计了高速数控轧辊磨床静压、动压及动静压、低压润滑3种供油系统,在此基础上,开发出了高速数控轧辊磨床液压供油试验平台,为高速数控轧辊磨床的国产化提供了有力的支撑.%Three kinds of oil supply systems were designed respectively, namely, static pressure oil supply system, dynamic pressure and dynamic/static pressure oil supply system, low pressure lubrication oil supply system, for the high-speed CNC roll grinder based on existing technologies of the domestic traditional CNC roll grinding machine. On the basis, the hydraulic oil supply test platform for the high-speed CNC roll grinder was developed. Thus, powerful experiment support is provided for producing domestically high-speed CNC roll grinder.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  19. The calculation and application of rolling force of foil mill%铝箔轧制力的计算与应用

    Institute of Scientific and Technical Information of China (English)

    贲洪艳; 辛达夫

    2009-01-01

    轧制力计算是轧机设计的基本参数之一,也是编制轧制工艺不可或缺的重要参数.在现有的技术文献中,计算轧制力的公式很多.但是要找到适合现场,快速、准确、简便的计算铝箔轧制的轧制力的计算公式却十分困难.根据现场的实践经验,并参照多家世界知名的轧机制造厂商的轧制力计算结果,总结出了便于现场使用的铝箔和板带轧制力的计算公式.%The calculation of rolling force is the basic parameter of design for rolling mill and prepare rolling process. The formula to calculate for rolling force can be found everywhere. But to inquire a correct, simple and convenient formula fit using at side that is very difficulty. Based on practice and compared with many calculated result from famous rolling mill manufactures, the formula to calculate for rolling force fit using at side is summde out.

  20. Factors Affecting the Development of Oxide Scales on Austenitic Stainless Steels during Hot Rolling in Steckel Mills

    Science.gov (United States)

    Cobo, S. J.; Rainforth, W. M.

    2008-10-01

    The hot rolling of austenitic stainless steels in Steckel Mills introduces particular characteristics to the development of oxides scales and surface structures. In this work, the formation of oxide structures during multipass hot rolling of 302 steel was studied under different sets of processing parameters in a laboratory system designed for the simulation of the Steckel process. The resulting surface structures were characterized by a set of complementary techniques involving scanning electron microscopy, energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), and glow discharge optical spectroscopy (GDOS). The surface analysis revealed two alternative surface structures: one consisting in a thin protective oxide layer rich in Cr2O3 and the other consisting in thick complex structures containing several successive nonprotective oxide scale and metal layers resulting from a cyclic oxidation pattern involving stages of protective oxidation, chemical breakaway, and duplex oxidation. The critical condition that determined the activation of one mechanism or the other was identified associated with the parabolic rate constant for Cr2O3 growth and the diffusivity of Cr in the alloy. The effects of changes in temperature, deformation, and furnace atmosphere are discussed. Alternatives for controlling scale development are presented.

  1. 圆弧头立铣刀端刃CNC磨削仿真技术研究%Research on CNC grinding simulation technology of torus end milling cutter's end edges

    Institute of Scientific and Technical Information of China (English)

    刘建军; 黎荣; 程雪锋; 金晓波; 丁国富

    2012-01-01

    A technology on universal end edges model and CNC grinding simulation of torus end milling cutters is introduced. With the theory of space vector rotation,the universal mathematic model of end edges above center or not was builded. Based on the accurate cutting - edge model, the grinding processes of the end milling cutter end - edge rake & flank faces were researched, and also the wheel' s moving path and tool axis vector were calculated. Meanwhile, the post processing program of five-axis NC grinder and the virtual simulation environment based on VERICUT software were developed, and three kinds of end-edge models with different tooth number were geted through grinding simulation,which validated acquired cutter location data. Taking four edges end milling cutter with two edges above center as example, the grinding simulation technology proposed was verified by measuring the structure parameters of simulation model and physical model,and comparing them with design parameters.%介绍一种圆弧头立铣刀端刃的通用建模及CNC磨削仿真技术.运用空间矢量旋转原理,对过中心和不过中心端齿刃线建立通用数学模型.基于所建立的精确刃线数模,研究了立铣刀端刃前、后刀面的磨削加工工艺并计算出砂轮的运动轨迹和刀轴矢量.开发了五轴数控磨床的后置处理程序和基于VERICUT软件的虚拟仿真环境,加工出三类不同齿数的立铣刀端齿模型,对获得的刀位数据正确性进行了验证.以两齿过中心的四齿平底立铣刀为例,通过测量仿真模型和加工实物的结构参数并与设计参数进行对比,验证了提出的磨削仿真技术的可行性.

  2. CVC冷轧机承载辊缝凸度调节域计算模型%Model of CVC Cold Rolling Mill Loaded Roll Gap Crown Control Room

    Institute of Scientific and Technical Information of China (English)

    李勇华; 邸洪双; 刘光明; 郝亮

    2011-01-01

    The crown control room prediction model of loaded roll gap of 4-high CVC cold rolling mill was developed.The loaded roll gap was divided into two parts, unloaded roll gap crown and deformation roll gap crown.Taking a CVC mill as an example, the model calculated result was consistent with the result that calculated by influence function method.It could be used to preset the shape crown of different actual production conditions on line.%开发了四辊CVC冷轧机承载辊缝凸度调节域预报模型,其将承载辊缝分为空载辊缝凸度与变形辊缝凸度两部分.以某厂CVC轧机为例,计算的凸度调节域与影响函数法计算的凸度调节域相吻合,可在线对不同工况下的轧机进行板凸度的预设定.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Influence of dry grinding in a ball mill on the length of multiwalled carbon nanotubes and their dispersion and percolation behaviour in melt mixed polycarbonate composites

    OpenAIRE

    Krause, Beate; Villmow, Tobias; Boldt, Regine; Mende, Mandy; Petzold, Gudrun; Pötschke, Petra

    2011-01-01

    Abstract Ball milling of carbon nanotubes (CNTs) in the dry state is a common way to produce tailored CNT materials for composite applications, especially to adjust nanotube lengths. For NanocylTM NC7000 nanotube material before and after milling for 5 and 10 hours the length distributions were quantified using TEM analysis, showing decreases of the mean length to 54 and 35%, respectively. With increasing ball milling time in addition a decrease of agglomerate size and an increase ...

  5. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  6. 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

    Directory of Open Access Journals (Sweden)

    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. 

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Introduction of common faults and routine maintenance of rolling mill bearing%浅谈轧机轴承的常见故障与日常维护

    Institute of Scientific and Technical Information of China (English)

    刘聪; 柴飞

    2014-01-01

    本文从轧机轴承的常见故障及原因分析,轧机轴承的日常维护等角度入手,研究轧机轴承的特性与如何做好维护工作,从而提高轴承的使用寿命,保证生产的顺利进行。%in this paper,based on common faults,Cause analysis and routine maintenance of rolling mill bearing,study the characteristics of rolling mill bearing and how to do maintenance work,in order to improve the service life of bearing and keep production running continuously.

  9. 大棒轧线粗轧机控制系统的优化和应用%Optimization and application of stick rolling line control system for rough rolling mill

    Institute of Scientific and Technical Information of China (English)

    马世雷

    2016-01-01

    本文主要介绍了莱钢特钢新区100吨电炉轧钢生产线粗轧机区域的概况,根据实际生产过程中的控制缺陷和不稳定因素,开始对控制进行优化。从轧制质量和控制系统稳定性出发,陆续开发了翻钢机推床自动对中功能、设备虚拟技术应用以及轧机辊缝计算模型开发等功能,提高了轧机控制系统的稳定性,提升了产品质量。%In this paper are introduced overview of rough mill of Laiwu Iron and Steel General District 100 ton electric furnace steel rolling production line area,begin to optimize the control according to the actual production process control defects and unstable factors.From the rolling quality and the stability of the control system of continue to develop the steel pusher automatic function, equipment application virtualization technology and roll seam and the function of calculating the development model,to improve the stability of the rolling mill control system,to enhance the quality of products.

  10. 冷轧高端装备的应用与推广%Application and Promotion of High-End Cold Rolling Mills

    Institute of Scientific and Technical Information of China (English)

    孟文华; 黄彦峰; 孙立峰

    2016-01-01

    18-H, 20-H and TRB cold mills, as high-end cold rolling equipment, are being highly demanded for the production of stainless steels, silicon steels, thin precision steels, high strength steels and steel plates with variable cross-section. Since at present, conventional cold rolling mills are keeping the demand low and the market is highly competitive, the development of high-end cold rolling mills can offer new economic growth point for metallurgical equipment builders.%作为冷轧高端装备十八辊,二十辊及TRB轧机,在不锈钢、硅钢、精密薄带钢、高强钢及变截面板轧制领域拥有很大的市场需求。在现今传统冷轧装备需求低迷,竞争激烈的市场环境下,开发高端冷轧装备,可为冶金装备制造企业找到新的经济增长点。

  11. Decoupling control based on terminal sliding mode and wavelet network for the speed and tension system of reversible cold strip rolling mill

    Science.gov (United States)

    Fang, Yiming; Liu, Le; Li, Jianxiong; Xu, Yanze

    2015-08-01

    To weaken the nonlinear coupling influences among the variables in the speed and tension system of reversible cold strip rolling mill, a novel dynamic decoupling control strategy is proposed based on nonsingular fast terminal sliding mode (NFTSM) and wavelet neural network (WNN). First, nonlinear disturbance observers are developed to counteract the mismatched uncertainties, and then input/output dynamic decoupling and linearisation for the speed and tension nonlinear coupling system are realised by utilising the inverse system theory. Second, nonsingular fast terminal sliding mode controller (NFTSMC) for each pseudo linear subsystem is presented based on backstepping and two-power reaching law, so as to improve the global convergence speed and robust stability of the system. Third, adaptive WNNs are used to approximate the uncertain items of the system, so as to improve the control precision of the speed and tension of reversible cold strip rolling mill. Theoretical analyses show that the NFTSMs satisfy reachability condition, the system error variables can converge to equilibrium point in finite time, and the resulting closed-loop system is globally asymptotically stable. Finally, simulation research is carried out on the speed and tension system of a 1422 mm reversible cold strip rolling mill by using the actual data, and results show the superiority of the proposed control strategy in comparison with the strategies of cascade PI, linear sliding mode control and internal model control.

  12. Application and Development of Simulation Technology in Cold Continuous Rolling Mill%仿真技术在冷连轧系统的应用及发展

    Institute of Scientific and Technical Information of China (English)

    崔建江; 吴胜昔; 袁枫华; 徐心和

    2001-01-01

    This paper analyses a dynamic simulation system of cold rolling mill and discusses the status and signification of simulation application and development of cold rolling mill in our country and foreign countries. Modeling and process of simulation in cold rolling mill are analysed. The execution of dynamic simulation includes the advanced modelling technology and time coordination scheduling and the use of multi-advanced simulation technology, such as coordernation simulation, simulation database, and integrated simulation. In this field virtual reality and intelligent simulation maybe act as future development in the end.%分析了一类冷连轧动态仿真系统,综述了仿真技术在冷连轧中在国内外的应用发展现状、以及发展冷连轧动态系统的意义。分析了仿真动态系统的建模及实现过程,冷连轧动态仿真的实施包含先进的模型化技术及时间协调调度,多种先进仿真技术的使用如协调仿真、仿真数据库技术一体化仿真。最后展望了该领域在虚拟现实和智能仿真技术的今后发展方向。

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Improving milling and production of a dust-producing unit equipped with hammer mills

    Energy Technology Data Exchange (ETDEWEB)

    Vorotnikov, Ye.G.; Nikiforov, A.A.; Rasputin, O.V.; Sukhunin, V.I.

    1982-01-01

    This paper presents generalized experience for deriving coarse ground coal dust in hammer mills by providing comparison data on improving efficiency of operation of the unit when switching to a coarser-type grind of the fuel. Need to have more precise formulas to calculate grinding potential of hammer mills when using a coarser grind is shown.

  15. 磨削印刷线路板铣刀时的锯齿现象及其消除%The aliasing phenomenon and its elimination during the grinding of PCB milling cutters

    Institute of Scientific and Technical Information of China (English)

    林高安

    2011-01-01

    The edge aliasing phenomenon on the cutter used for printed circuit board (PCB) milling often occur during the grinding with diamond wheel. In this paper, the effects of wheel diamond grit size, wheel speed and feed rate on the edge aliasing were studied. The results showed that the quality of cutting edge of milling cutter was improved with the decrease of wheel diamond grit size. The wheel speed and feed rate also had influence on the quality of the cutting edge. The wheel diamond grit size was the most important influencing factor on the cutting edge.%本文针对金刚石砂轮磨削印刷线路板(PCB)铣刀过程中铣刀切削刃产生的锯齿现象进行了分析,研究了砂轮粒度、砂轮转速以及切沟速度对铣刀切削刃锯齿的影响.研究结果表明,随着砂轮粒度的减小,切削刃质量得到提高,砂轮转速和切沟速度对切削刃质量都有影响,其中砂轮粒度对切削刃质量的影响最为重要.

  16. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  17. 宽带钢热轧机CVC辊型优化与应用%Optimization and Application of CVC Roll Contour on Hot Wide Strip Mill

    Institute of Scientific and Technical Information of China (English)

    杨晖

    2011-01-01

    In view of unreasonable of amount and distribution of work roll shifting in full stroke and short ability of crown control of F5 ~F7 mills in 2250mm hot wide strip line of Lianyuan Iron &-Steel Co. , the CVC roll contour was optimized by building models. The industry experiment shows that the work roll utilization ratio of shifting in full stroke is effectively improved, and the shape control function of work roll bending is also gotten better.%针对涟钢2250mm常规热连轧机组F5~F7机架CVC工作辊横移量及分布不合理、轧机凸度控制能力不足的问题,通过建立CVC辊型模型对其进行了优化设计.现场实验表明,CVC辊型优化后,工作辊横移全行程利用率得到了有效提高,工作辊弯辊的板形调控功效也得到了更好发挥,满足了板形控制的需要.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  19. Design of Tension Roller in Cold Rolling Mill for Stainless Steel%不锈钢冷连轧机组张力辊设计计算

    Institute of Scientific and Technical Information of China (English)

    郭爱华

    2015-01-01

    本文对不锈钢冷连轧机组所用张力辊的几何参数、材质、传动功率进行了计算选型,避免了电机功率不够而导致的带钢打滑或电机功率过大而造成的浪费。%Materials were selected and geometrical parameters, and transmission power were calculated in the design of the tension roller in stainless steel cold rolling mill, to avoid band steel slipping due to insufficient transmission power, or wastage due to overdue transmission power.

  20. The Use and Milling of Finishing Roll Pass%精轧钢筋孔型轧辊的铣削和使用

    Institute of Scientific and Technical Information of China (English)

    刘运桥; 宋春宝; 杨艳军; 赵礼; 褚文龙

    2015-01-01

    Chengde Iron and Steel Co.,Ltd.started to study the finishing rebar rolling of PSB830 since 2009.Its char-acteristic is using connector with inner thread or screw connection with a screw nut for fixing in bar of arbitrary cross sec-tion,so it is very important to research the shape of finishing rebar,which is difficulty in roll rib groove milling.Through engineer and technologist practice and exploring,according to the requirements of the rolling thread dimensions,we deter-mine the shape of the tool in size and angle.With tool trajectory calculation,we accurately calculate the tool of gyration ra-dius,Z axis starting position and cutter length,give the correct value of speed,and let roll rib groove milling be successfully completed.This process has changed the traditional method of cutting the rib groove,shorten the adjustment time,in-creased the output per hour,and provided reliable guarantee for the success of the steel rolling mill batch.%承德钢铁有限公司自2009年开始研究轧制 PSB830精轧钢筋,其使用特点是在钢筋的任意截面处都能用带有内螺纹的连接器联接或拧上螺帽进行锚固,所以精轧钢筋外形是重要的研究内容,外形轧制的难点在于轧辊肋槽的铣削。通过实践摸索,根据精轧螺纹外形尺寸要求,确定了刀具的外形尺寸和角度,计算了刀具的运行轨迹,并精确地计算出了刀具的回转半径、Z 轴起点位置和铣刀长度,依此给出了速度修正值,使轧辊肋槽的铣削顺利完成。该工艺改变了传统肋槽的铣削方法,缩短了调整时间,提高了小时产量,为精轧钢筋的批量成功轧制提供了保障。

  1. Ultra-fine grinding and mechanical activation of mine waste rock using a high-speed stirred mill for mineral carbonation

    Institute of Scientific and Technical Information of China (English)

    Jia-jie Li; Michael Hitch

    2015-01-01

    CO2 sequestration by mineral carbonation can permanently store CO2 and mitigate climate change. However, the cost and reaction rate of mineral carbonation must be balanced to be viable for industrial applications. In this study, it was attempted to reduce the carbonation costs by using mine waste rock as a feed stock and to enhance the reaction rate using wet mechanical activation as a pre-treatment method. Slurry rheological properties, particle size distribution, specific surface area, crystallinity, and CO2 sequestration reaction efficiency of the initial and mechanically activated mine waste rock and olivine were characterized. The results show that serpentine acts as a catalyst, in-creasing the slurry yield stress, assisting new surface formation, and hindering the size reduction and structure amorphization. Mechanically activated mine waste rock exhibits a higher carbonation conversion than olivine with equal specific milling energy input. The use of a high-speed stirred mill may render the mineral carbonation suitable for mining industrial practice.

  2. 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

    International Nuclear Information System (INIS)

    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

  3. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Design of Universal Grinding Device Using in Vertical Turning and Milling Center%应用于立式车铣中心的万能磨削装置的设计

    Institute of Scientific and Technical Information of China (English)

    喻鹏; 刘兴卓; 洪寿福

    2013-01-01

    The universal grinding device that using in the Vertical Turning and Milling Center was included with electric spindle and manual universal mechanism.The power supply and cooling liquid circulating system was integrated in the machine tool,with which the integrated multi-processing could be realized when the workpiece was clamped in one time.By using this device,working accuracy of machine tool is improved,and the working efficiency is improved greatly.%应用于立式车铣中心的万能磨削装置,包括电主轴及手动万能机构,其电源与冷却液循环系统集成在立式车铣中心机床上,可实现工件一次装卡,多种工序集成加工.使用该装置,提高了机床工作精度,同时大大提高了工作效率.

  5. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  6. Research and application of cold rolling mill air blowing system%冷轧轧机空气吹扫系统的研究与应用

    Institute of Scientific and Technical Information of China (English)

    仝玉华

    2016-01-01

    Cold-rolled production line trial production since, mill emulsion blow sweep system of steel plate surface residues of the emulsion has been unable to effectively clean and purge, emulsion spot defects caused by, especially in the rolling of thin gauge products because of plate is not easy to control, emulsified liquid extrusion stem and plugging effect of the emulsion of the poor, emulsion continuous or not continuously from the squeezing roll gap to bring out and entrained into the steel volume forming emulsion spot trace.%莱钢冷轧生产线试生产以来,轧机乳化液吹扫系统对钢板板面残留的乳化液一直不能有效吹扫干净,造成乳化液斑迹缺陷,特别是在轧制薄规格产品时由于板型不易控制,乳化液挤干辊对乳化液的封堵效果不佳,乳化液连续或不连续地从挤干辊缝隙中带出而夹带到钢卷中形成乳化液斑迹。

  7. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  8. GRINDING OF DOUBLE DISC GRINDING MACHINE

    Institute of Scientific and Technical Information of China (English)

    Hu Huiqing

    2005-01-01

    The grinding of two parallel sides of a component is accomplished with the accuracy and higher productivity by passing a blank through the truncated cone shape grinders, which are turned angles. The machine is designated by the name of double disc grinding machine (DDGM). Usually, it is used in the mass production. The relationship between these angles, the accuracy, productivity,allowance and parameters of the machine and technology is explained in detail by math, such as vector analysis, transformation of 3D space coordinates, etc. Therefore, in the aspects of qualitative and quantitative analyses, the grinding potential of DDGM is enormous increased and superior to conventional methods. Furthermore, the theoretical foundation of DDGM grinding design and technology is provided to improve, to expand and to create for future. The established machine design and practical experience of grinding technology will get great benefit by them.

  9. Automatic Control System of Direct Tension-type Pilot Cold Rolling Mill%直拉式冷轧实验机自动控制系统

    Institute of Scientific and Technical Information of China (English)

    李建平; 杨红; 牛文勇; 王国栋

    2012-01-01

    为了满足钢铁企业加强冷轧生产技术研究能力的需要,轧制技术及连轧自动化国家重点实验室(RAL)自主设计开发了垂直方向采用液压自动厚度控制(HAGC),水平方向两侧通过液压缸和夹头产生张力进行自动张力控制(ATC)的新型直拉式可逆冷轧实验轧机.概要地介绍了直拉式冷轧实验机的设备构成及设备的主要功能和特点,详细说明了控制系统构成及自动控制功能的实现,通过系统测试给出了系统控制精度.测试结果表明冷轧实验工艺过程可以模拟生产工艺过程,进行冷轧钢种开发和工艺研究.%To meet iron and steel enterprises requires to strengthen research capacity in cold-rolled production technology, State Key Laboratory of Rolling and Automation(RAL) independently designed and developed a new direct tension-type pilot cold rolling mill, which includes a vertical hydraulic automatic gauge control(HAGC) generating tension through the hydraulic cylinders and chucks on both sides o{ the horizontal direction to realize automatic tension control (ATC). The equipment constitute, main functions and features of direct tension-type pilot cold rolling mill were introduced briefly. The control system structure and the realization of automatic control functions were illustrated. The control precisions were gotten through system testing. The testing results showed that the experimental process may simulate the cold roiling production process to develop steel grade and research technology.

  10. Development and Application of Pressure-Equalizing Back-Up Roll Contour in Hot Strip Mill%宽带钢热连轧机组均压支承辊辊形开发与应用

    Institute of Scientific and Technical Information of China (English)

    王晓东; 李飞; 李本海; 张宝辉; 王磊; 陈超超

    2012-01-01

    CVC(Continuous Variable Crown) work roll contour technology since its invention was applied in more than 150 hot rolling mills throughout the world for controlling strip shape.However,in actual application,there were uneven wear on rolls or even roll spalling problems because contact pressure concentrations existed between work and back-up rolls when flat or CVC back-up roll was used for configuration with CVC work roll during the rolling.For solving these defects,a pressure-equalizing back-up roll contour with combination of VCR(Variable Crown Back-up Roll) and CVC back-up roll contours was designed and applied on a hot rolling mill.It not only has the feature of VCR back-up roll contour,but also can improve the contact condition between work and back-up roll.After the application of pressure-equalizing back-up roll contour,roll spalling problem was solved,and strip profile quality was also improved.%CVC工作辊辊形自发明以来在全球150多条热连轧生产线上得到应用,以控制带钢的板形。实际应用中,与CVC工作辊配对使用的支承辊无论采用平辊还是CVC辊形均存在非均匀磨损甚至轧辊剥落失效的问题,主要原因是CVC支承辊辊形和平支承辊与CVC工作辊配置时存在接触压力集中。为了解决此问题,设计并应用了一种均压支承辊辊形与CVC工作辊配置使用。此辊形是变接触支承辊辊形(VCR)与CVC支承辊辊形的组合,具有变接触辊形的优点,同时又能更好地与CVC工作辊配置使用。均压支承辊辊形应用后,改善了CVC工作辊与支承辊辊间接触状态,解决了轧辊剥落问题,并改善了带钢凸度质量。

  11. A Study on Fault Diagnosis of Rolling Bearing in High Speed Wire Rolling Mill%高线轧机滚动轴承故障诊断的研究

    Institute of Scientific and Technical Information of China (English)

    汪超; 张键

    2014-01-01

    When the rolling bearing fault occurs in the high -speed wire mill ,obvious impact character-istic can be found in the pictures of time domain by the vibration analysis .It can be seen that obvious time interval exists in the autocorrelation function ,that the probability density function image is not normally distributed ,that the amplitude increases obviously in the pictures of vibration trend and exceeds the allow-able values ,that kurtosis value is generally more than 4 ,and that obvious continuity and high peak value at the frequency in the fall picture are considered to be bearing potential fault .By monitoring the bearing inner ring ,outer ring ,rolling body cage ,and holder ,five forms of damage are done to the bearing inner ring ,rolling body and the outer ring and three forms of damage to the holder .Due to high sensitivity of rotation frequency of the inner ring ,inner side of the rolling body ,outer ring of the rolling body to surface defects ,it is regarded as the most effective in the course of monitering .%高线轧机滚动轴承出现故障时,通过振动分析,在时域图中有明显冲击特征,自相关函数有明显的时间间隔,概率密度函数图像不是正态分布,振动趋势图中振幅均有明显上升并超过允许值的现象,峭度值一般均超过4,瀑布图中在转频处出现明显的连续性且峰值较高,均是轴承存在潜在故障表像。从轴承内圈、滚动体、保持架和外圈四个部分进行监测,轴承内圈、滚动体和外圈有五种常见损坏形式,保持架有三种常见损坏形式。由于内圈旋转频率、滚动体过内圈的频率和滚动体过外圈的频率对表面缺陷有较高的灵敏度,在监测过程中是最有效的。

  12. Comprehensive modeling approach of axial ultrasonic vibration grinding force

    Institute of Scientific and Technical Information of China (English)

    HE Yu-hui; ZHOU Qun; ZHOU Jian-jie; LANG Xian-jun

    2016-01-01

    The theoretical model of axial ultrasonic vibration grinding force is built on the basis of a mathematical model of cutting deforming force deduced from the assumptions of thickness of the undeformed debris under Rayleigh distribution and a mathematical model of friction based on the theoretical analysis of relative sliding velocity of abrasive and workpiece. Then, the coefficients of the ultrasonic vibration grinding force model are calculated through analysis of nonlinear regression of the theoretical model by using MATLAB, and the law of influence of grinding depth, workpiece speed, frequency and amplitude of the mill on the grinding force is summarized after applying the model to analyze the ultrasonic grinding force. The result of the above-mentioned law shows that the grinding force decreases as frequency and amplitude increase, while increases as grinding depth and workpiece speed increase; the maximum relative error of prediction and experimental values of the normal grinding force is 11.47% and its average relative error is 5.41%; the maximum relative error of the tangential grinding force is 10.14% and its average relative error is 4.29%. The result of employing regression equation to predict ultrasonic grinding force approximates to the experimental data, therefore the accuracy and reliability of the model is verified.

  13. CZKQ5263龙门式车铣钻磨加工中心结构设计和优化%Structure Design and Optimization for CZKQ5263 Gantry-typed Machining Center of Turning, Milling, Drilling and Grinding

    Institute of Scientific and Technical Information of China (English)

    韩玉坤; 张运真; 张传生

    2012-01-01

    To process large plate covered parts, based on the structure of vertical lathe, a modular machine tool with a movable gantry and a traditional vertical lathe worktable was designed. In the case of a fixture, the turning, milling, grinding of cylindrical surface, end surface and ring groove and the drilling, reaming of holes on the large plate covered parts were completed, reducing clamping times, saving time of handling, lifting and clamping part. A three-dimensional model of the whole modular machine tool was built and the multi-body kinematic analysis was made. Aiming at the key component, finite element analysis was carried out to optimize its structure.%针对大型盘盖类零件的加工要求,参照立式车床的结构,设计一种由可动式龙门框架和传统立车工作台组合而成的机床.在一次装夹的情况下,能够完成大型盘盖类零件的外圆、端面和环槽的车、铣、磨以及钻、铰孔等工作,可减少装夹次数,节约搬运、吊装、装夹的时间.建立了整机的三维模型并进行了多体运动学分析,针对关键零件进行了有限元分析和仿真设计,改善了产品的结构.

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  16. Measures for Improving Qualified Rate of Thin-walled Cylinder Set on the Center-less Grinding Mill%提高薄壁缸套在无心磨机床上磨削合格率的改进措施

    Institute of Scientific and Technical Information of China (English)

    裘俊彦; 田锋

    2011-01-01

    Aiming at the qualified rate about 90% questions that the thin-walled cylinder set on the center-less grinding mill in the batch production, the major causes of "arris cylindric" , "arris-shaped" and "taper" of the thin-walled cylinder after grinding were found out. By improving the center position of cylinder liners, pallets and wheel position, and the position of the guides, and adjusting the cooling mode, determining a reasonable amount of grinding, grinding parameters and other measures, the product qualified rate was improved to more than 99% , and significant economic benefit was achieved. This improvement measures have certain reference value for other thin-walled socket parts finishing external circular surface grinding.%针对批量生产中薄壁缸套在无心磨机床上磨削的合格率只有90%左右的问题,找出薄壁缸套磨削后产生“棱圆度”、“棱边形”、“锥度”等主要误差项目的成因;通过改进缸套中心位置、托板与磨轮的位置、导板的位置,以及调整冷却方式、确定合理的磨削用量、磨削条件等措施,将产品合格率提高到99%以上,取得了显著的经济效益.这种改进措施对于其他薄壁套筒类零件的精加工外圆表面磨削具有一定的参考价值.

  17. Study on Roll Elastic Deformation Asymmetrical 4-High Mill Stiffness%四辊轧机不对称刚度条件下轧辊弹性变形的研究

    Institute of Scientific and Technical Information of China (English)

    龚殿尧; 徐建忠; 袁方成

    2012-01-01

    针对国内某热连轧厂精轧机组某机架轧机两侧刚度不对称的实际情况,为了研究四辊轧机驱动侧和操作侧刚度不对称条件下轧辊弹性变形的规律,采用影响函数法开发了基于双悬臂梁模型的轧辊弹性变形模拟计算模块,对刚度不对称时的四辊轧机进行了受力分析,对轧辊和轧件进行了离散化,给出了关键的影响函数.使用该计算模块并结合现场实际数据计算了不同刚度差条件下工作辊的弹性挠曲、工作辊与轧件之间的压扁、工作辊与支撑辊之间的弹性压扁、轧制力的横向分布和辊间压力的横向分布规律,研究了不同刚度差条件下轧件出口断面形状的变化规律.%According to the real condition of different stiffness between the driving side and operating side of some stand mill in a hot strip factory, a calculation module was developed using influence coefficient method based on dual cantilever beam theory to research the regularity of roll elastic deformation under the condition of asymmetrical stiffness. Force analysis of 4-high mill under asymmetric condition was demonstrated, the roll and work piece were discretized following the principle of influence coefficient method, and the key influence functions were presented. The module was used to calculate and analyze the elastic deflection of work roll, the bruise between work roll and backup roll, the bruise between work roll and work piece, the rolling force and roll load distribution in lateral direction between work roll and backup roll with different stiffness differences. The profile of the rolled work piece with different stiffness differences were calculated and analyzed.

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

    International Nuclear Information System (INIS)

    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%.

  19. Measurement of moisture in mill feed ore

    Energy Technology Data Exchange (ETDEWEB)

    Timm, A.R.; Moench, P.; Moisel, E. (Council for Mineral Technology, Randburg (South Africa))

    1985-04-01

    The control of the moisture in the feed to a mill is very important for efficient mill operation. Water is added continuously to the ore fed to a mill to maintain a suitable mix of ore and moisture in the mill. However, problems arise because of the large variation in the moisture content of the ore, which affects the efficiency of the grind. If too little moisture is present, the mill is unable to grind the ore finely enough, creating instead a thick 'porridge' that causes the mill to choke up. On the other hand, too much moisture results in inefficient grinding because the ore is flushed through the mill too quickly. Several techniques are available for measuring moisture and Mintek undertook an investigation in an attempt to develop a reliable robust moisture meter suitable for monitoring the moisture content of ore, which include the following: neutron backscattering, infrared absorption, microwaves, capacitance and moisture as a function of conductivity.

  20. Work index and grinding energy assessment of Dilband iron ore Pakistan

    International Nuclear Information System (INIS)

    Importance of comminution in mineral processing sector is highly acknowledged from energy perspective. In present study an attempt was made to understand the commuting behavior of Dilband iron ore and to compute the grinding energy requirement for production of ultra fine particles up to mesh of liberation. In this regard standard grind ability tests developed by the Chair of Mineral Processing Leoben Austria was used for calculating work index of Dilband iron ore. The grinding tests were conducted in rod and ball mills. The work index value of two feed size fractions with 80% passing at 3800 macro m and 5200 macro m was noted to be 11.85 kwh/t and 9.3 kwh/ton respectively. Ball mill grinding test indicates that dry grinding in open circuit is not efficient and consumes more energy of 88.48kwh/t of ore for grinding 1000/40 macro to 80% <40 macro m size. (author)

  1. Parametric Design on Rollers of Large-diameter Three-roller Cold-rolling Pipe Mill%大直径三辊冷轧管机轧辊的参数化设计

    Institute of Scientific and Technical Information of China (English)

    贾其苏; 双远华; 张志娜; 张志武

    2014-01-01

    Roller is the core of groove design for large-diameter three-roller cold-rolling pipe mill. This paper takes Solidworks as the secondary development platform to carry out parametric design on rollers of large-diameter three-roller cold-rolling pipe mill by using C#,and introduces the basic principles and the key developing progress of par-ametric design. The design is connected with groove design software of large-diameter three-roller cold-rolling pipe mill. The design can model the roller rapidly,accelerate development cycles of groove design and strengthen com-petitive power of product.%轧辊是大直径三辊冷轧管机孔型设计的核心。以三维造型软件Solidworks为开发平台,使用C#语言对大直径三辊冷轧管机的轧辊进行参数化设计,阐述参数化建模的基本原理和开发过程。该设计对接大直径三辊冷轧管机特有的孔型设计软件,实现轧辊模型的快速设计,缩短孔型研发周期,提高产品竞争力。

  2. Vertical Short Crack Initiation in Medium Carbon Bainitic Steel Under Mild Tractive Rolling Contact

    Institute of Scientific and Technical Information of China (English)

    DOU Peng; SUO Shuang-fu; BAI Bing-zhe; YANG Zhi-gang; LI You-guo

    2008-01-01

    To improve the current grinding procedure of the back-up roll of CVC hot rolling mills so that the back-up roll service life can be extended, the crack initiation and propagation behavior of medium carbon bainitie back-up roll steel was investigated, a kind of asperity-scale, surface originated vertical short cracks occurred at 5 × 102 -1 × 104 cycles. Theoretical analysis indicated that the maximum tensile stress occurring at the back edge of the contact of as-perities keeps at above 1 347. 97 MPa, and ratcheting and cyclic plastic deformation take place at such sites within 1 × 104 cycles. The early initiation of the vertical short cracks is caused by the asperity contact. According to the crack initi-ation mechanism, short crack behavior and preventive grinding strategy, steel consumption can be reduced considera-bly by decreasing the surface roughness and removing the asperity influenced surface thin layer at about 70%-80% of the surface distress life.

  3. 1580热轧R2粗轧机主传动十字轴失效分析%Invalidation analysis for main driving cross axle of R2 roughing mill in 1580 hot rolling mill

    Institute of Scientific and Technical Information of China (English)

    廖永锋

    2011-01-01

    对宝钢1580热轧R2粗轧机主传动十字轴的失效原因进行了分析,指出该十字轴主要是在1.5倍额定负荷以上的工况条件下产生接触疲劳破坏,并提出了对十字轴表面重新加工处理,使其恢复表面硬度和粗糙度,重新单配轴承的修复方案,延长了十字轴的使用寿命.%The invalidation reason of R2 main driving cross axle in Baosteel 1580 hot rolling mill is analyzed.It is pointed out that the contact fatigue failure of the cross axle is due to more than 1.5 times of nominal load under working condition.An approach to treat the damaged working surface of the cross axle, and recover its surface stiffness and roughness, then make up bearing is put forward, and that service life of cross axle is prolonged.

  4. 1880热轧SSP定宽机结构特点分析%Structural feature analysis for slab sizing press In 1880 Hot Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    刘松; 廖永锋

    2011-01-01

    The gap of tooth flank in the main reduction box was reduced by analyzing the structures, motion process and carrying capacety of crank shaft, inner block and outer block in the slab sizing press ( SSP) in 1880 hot rolling mill. The method has a certain effect to lower the noise and eliminate the reverse direction impact of gear teeth. The wear limit of 4 mm for the curved plate and 0. 7 mm for the sector gear is defined as a standard for maintenance of SSP. The routine inspection each year for the curved plate and sector gear is also roled. It ensured the smooth running of SSP.%本文通过对1880热轧SSP定宽机关键部件如曲轴、内块、外块等的结构、运行过程、受力情况进行了分析与研究,确保SSP设备稳定运行.主减速机采用小侧间隙对降低噪音、反向打齿有一定作用.在定宽机维修技术标准中制定弧形板的磨损极限为4 mm,扇形齿的磨损极限为0.7 mm.

  5. 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

    Directory of Open Access Journals (Sweden)

    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.

  6. Study on anaerobic treatment of hazardous steel-mill waste rolling oil (SmWRO) for multi-benefit disposal route.

    Science.gov (United States)

    Ma, Huanhuan; Li, Zifu; Yin, Fubin; Kao, William; Yin, Yi; Bai, Xiaofeng

    2014-01-01

    Steel-mill waste rolling oil (SmWRO) is considered as hazardous substance with high treatment and disposal fees. Anaerobic process could not only transform the hazardous substance into activated sludge, but also generate valuable biogas. This study aimed at studying the biochemical methane potential of SmWRO under inoculum to substrate VS ratios (ISRs) of 0.25, 0.5, 1, 1.5, 2 and 3 using septic tank sludge as inoculum in mesophilic and thermophilic conditions, with blank tests for control. Specific biogas yield (mL/g VS(added)), net biogas yield (mL/g VS(removed)) and VS removal were analyzed. The ANOVA results indicated great influence of ISR and temperature on studied parameters. ISR of 1.5 at 55°C and ISR of 1.5 and 2 at 35°C were suggested with the highest specific biogas yield (262-265 and 303mL/g VS(added)). Kinetic analysis showed that Gompertz model fit the experimental data best with the least RMSE and largest R(2).

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

    International Nuclear Information System (INIS)

    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.

  8. 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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, Jumpei [Materials Science and Engineering Programme and Nanotec Center of Excellence at Mahidol University, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand); Limpanart, Sarintorn; Khunthon, Srichalai [Metallurgy and Materials Research Institute, Chulalongkorn University, Phayathai, Bangkok 10330 (Thailand); Osotchan, Tanakorn [Materials Science and Engineering Programme and Nanotec Center of Excellence at Mahidol University, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand); Physics Department, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand); Traiphol, Rakchart [Laboratory of Advanced Polymers and Nanomaterials, Department of Chemistry and Center for Innovation in Chemistry, Faculty of Science, Naresuan University, Phitsanulok 65000 (Thailand); Srikhirin, Toemsak, E-mail: sctsk@mahidol.ac.th [Materials Science and Engineering Programme and Nanotec Center of Excellence at Mahidol University, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand); Physics Department, Faculty of Science, Mahidol University, Rajathavee, Bangkok 10400 (Thailand)

    2010-10-01

    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.

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

    International Nuclear Information System (INIS)

    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

  11. STABLE DIAMOND GRINDING

    Directory of Open Access Journals (Sweden)

    Yury Gutsalenko

    2010-06-01

    Full Text Available The paper generalizes on the one hand theory of kinematic-geometrical simulation of grinding processes by means of tools with working part as binding matrix with abrasive grains located in it in random manner, for example diamond grains, and on the other hand practical performance of combined grinding process, based on introduction of additional energy as electric discharges and called by the organization-developer (Kharkov Polytechnic Institute «diamond-spark grinding» as applied to processing by means of diamond wheel. Implementation of diamond-spark grinding technologies on the basis of developed generalized theoretical approach allows to use the tool with prescribed tool-life, moreover to make the most efficient use of it up to full exhausting of tool-life, determined by diamond-bearing thickness. Development is directed forward computer-aided manufacturing.

  12. 冶金轧机主传动交流调速系统的发展及应用%Development and Application of AC Adjustable Speed System for Main Drive of Metallurgical Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    张勇军; 何安瑞

    2015-01-01

    冶金轧机主传动系统作为生产线的核心装备具有装机容量大、系统可靠性高、过载能力强、动态响应快等特点,目前主导的轧机主传动电气控制已由直流系统变为交流系统。介绍并比较了几种轧机传动系统中主要的交流调速方案,对其适用范围和优缺点进行了分析,重点介绍了采用新型可关断电力电子器件的三电平PWM变频调速系统的结构和特点,同时探讨了我国目前大功率轧机主传动交流调速系统的研究和应用现状,为冶金企业大功率轧机主电机传动装置的设计选型提供参考。%Serving as the key equ ipment, the main drive system of the metallurgical rolling mill has such characteristics as large installed capacity, high reliability, high overload capacity, fast dynamic response. At present, the electrical control for the main drive of the rolling mill was generated by the AC system instead of the DC system. The main AC adjustable speed schemes for the drive systems of several types of rolling mills were discussed based on the comparison, whose scope of application and merits and faults were analyzed. Especially the structure and characteristics of the 3-level PWM variable frequency adjustable speed system by using the new type of the turn-off power electronic devices were introduced and also the current situation of the research and application of the AC adjustable speed system for the main drive of domestic high-power rolling mills is discussed, all of which can provide the reference for selecting the designing scheme and types on the main motor drive devices of the rolling mills with high power used by metallurgical enterprises.

  13. Development and Application of Process Control System for the New Type Pilot Cold Rolling Mill%新型直拉式冷轧实验轧机过程控制系统的开发和应用

    Institute of Scientific and Technical Information of China (English)

    矫志杰; 何纯玉; 李建平; 孙建铭; 张莹; 刘相华

    2012-01-01

    为了满足冷轧新钢种开发和工艺研究的需求,研制了两侧通过液压缸和夹头产生张力的新型直拉式冷轧实验轧机。为该新型冷轧实验轧机配备了完备的检测仪表和自动化控制系统。其中过程控制系统的开发采用通讯功能与核心控制功能分离的两层进程结构,具备数据通讯、模型计算、过程跟踪和数据管理等功能。针对实验轧机的特点,模型计算功能可以灵活调整轧制规程,摸索工艺制度;数据管理功能分别对原始实际数据、轧制实际数据和轧制工艺统计数据进行记录、分析和处理。该新型冷轧实验轧机在国内得到大量的推广和应用,过程控制系统较好地满足了试验需要。%The new type pilot cold rolling mill was developed for the experiment of the cold rolling material and process research.The horizontally located hydraulic cylinders and clamps were used to apply tension on the strip.Instrumentations and automation control system were allocated on this new type pilot mill.Two running processes for the communication function and core control functions,such as model calculation,process tracking and data management,were designed in the process control system.For the characteristic of pilot cold mill,roll schedule can be adjusted flexibly to explore the process technology by model calculation function.Raw actual data,rolling actual data and rolling process data were recorded,analyzed and treated by date management function.This new type pilot cold rolling mill has been used in several domestic companies,and process control system has a good use.

  14. Grinding Properties of Abandoned Concrete

    Institute of Scientific and Technical Information of China (English)

    ZHENG Fang-yu; WANG Li-jiu; LI Qiang

    2007-01-01

    The grinding properties of abandoned concrete, which consists primarily of hardened cement, limestone aggregate and river sand, are studied. Theoretical models of grinding are used to explain the experimental observation. The results show that 1) The principle disintegration mechanism of hardened cement and river sand is volumetric grinding, although at later stages grinding of cement becomes difficult because of its flaked structure; 2) The limestone grinding process can be divided into two steps. First, volumetric grinding, with an obvious component of surface grinding, followed by primarily surface grinding as the micro-particle content increases; 3) Initially, the principle mechanism of grinding limestone and river sand is volumetric grinding, albeit less efficient grinding than if these components were ground separately, and; 4) After 10 to 20 min of grinding the grinding bottleneck phenomenon appears and after 20 min of grinding the content of micro-particles is large and surface grinding is the main mechanism while the particle size of the mixture is smaller than that of separately ground river sand and cement but bigger than that of separately ground limestone.

  15. Photoacoustic study of nanocrystalline silicon produced by mechanical grinding

    Energy Technology Data Exchange (ETDEWEB)

    Poffo, C.M. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, Campus Universitario Trindade, C.P. 476, 88040-900 Florianopolis, Santa Catarina (Brazil); Lima, J.C. de, E-mail: fsc1jcd@fisica.ufsc.b [Departamento de Fisica, Universidade Federal de Santa Catarina, Campus Trindade, C.P. 476, 88040-900 Florianopolis, Santa Catarina (Brazil); Souza, S.M.; Triches, D.M. [Departamento de Engenharia Mecanica, Universidade Federal de Santa Catarina, Campus Universitario Trindade, C.P. 476, 88040-900 Florianopolis, Santa Catarina (Brazil); Grandi, T.A. [Departamento de Fisica, Universidade Federal de Santa Catarina, Campus Trindade, C.P. 476, 88040-900 Florianopolis, Santa Catarina (Brazil); Biasi, R.S. de [Secao de Engenharia Mecanica e de Materiais, Instituto Militar de Engenharia, 22290-270 Rio de Janeiro, RJ (Brazil)

    2011-04-01

    Mechanical grinding (MG) was used to produce nanocrystalline silicon and its thermal and transport properties were investigated by photoacoustic absorption spectroscopy (PAS). The experimental results suggest that in as-milled nanocrystalline silicon for 10 h the heat transfer through the crystalline and interfacial components is similar, and after annealed at 470 {sup o}C the heat transfer is controlled by crystalline component.

  16. Method for grinding and delaminating muscovite

    Institute of Scientific and Technical Information of China (English)

    Shirleny Fontes Santos; Silvia Cristina Alves Franca; Tsuneharu Ogasawara

    2011-01-01

    A method of dry grinding muscovite based on the use of knife-mills is reported. It was possible to produce mica with a particle size below 100 and 45 μm. After grinding, the samples were submitted to sonication treatment, which promoted delamination of the material. The particle size distribution shows that sonicated mica has more particles in the size range 10-50 μm than does non-sonicated mica have.This also indicates a decrease in the average particle size. Characterization of the treated muscovite by scanning electron microscopy revealed a highly delaminated material with a plate-like structure. The products were characterized by chemical analysis and X-ray diffraction, too. This mica has already been used for the synthesis of pearlescent pigments.

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

    International Nuclear Information System (INIS)

    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.

  18. 高速轧机工作界面非稳态润滑过程界面动力学特性%Interface dynamic characteristics of high-speed rolling mill work interface based on unsteady lubrication process

    Institute of Scientific and Technical Information of China (English)

    王桥医; 陈娟; 高瑞进; 赵勇

    2013-01-01

    综合运用轧制理论、流体力学理论、摩擦润滑理论,建立考虑非稳态润滑过程轧机系统力学模型.该模型综合运用界面摩擦模型、轧制力、轧制力矩模型、流体动力润滑模型构成的多重耦合模型,定量分析高速轧机工作界面非稳态润滑过程界面动力学特性.研究结果表明:对于较小的压下率,摩擦应力很小,摩擦应力最大值发生在入口和出口的边缘处,并且在较小的压下率下油膜压应力变化非常小;在较大的张应力条件下,工作区压应力低,油膜剪切应力小,压力梯度也相当小;摩擦应力在入口和出口边缘达到最大;随着张应力的减小,油膜压力增大,剪切应力增大更快,最终达到了润滑油抗剪强度;在全膜润滑或者表面粗糙度很小的情况下,轧制力的平均值和轧制力变化的幅度随着压下率的增加而增加,轧制力的最小值几乎一样,不受表面粗糙度和压下率变化的影响;轧制力矩的变化趋势和轧制力的变化非常相似,然而对于带材表面粗糙度很大的轧制过程,轧制力矩的变化幅度比轧制力的变化小.%On the basis of rolling theory, hydromechanics theory, lubrication and friction theory, the mechanical model of rolling mill system based on the rolling gap during unsteady lubrication process was presented. In the analysis of interface dynamic characteristic process, the coupling model that consists of interface friction model, the rolling force and rolling torque model and hydrodynamic lubrication model was taken into account, and the interface dynamic characteristics of the high-speed rolling mill work interface based on unsteady lubrication process were discussed quantificationally. The results show that for small reductions, the friction stress values are low and their maximum values occur at the inlet and outlet edges, and for small reductions, the change of lubricant pressure is small. At high tension stress, the pressure

  19. Nitramine Drying & Fine Grinding Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Nitramine Drying and Fine Grinding Facility provides TACOM-ARDEC with a state-of-the-art facility capable of drying and grinding high explosives (e.g., RDX and...

  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

    Institute of Scientific and Technical Information of China (English)

    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. FEM Analysis of Rolling Pressure Along Strip Width in Cold Rolling Process

    Institute of Scientific and Technical Information of China (English)

    LIU Xiang-hua; SHI Xu; LI Shan-qing; XU Jian-yong; WANG Guo-dong

    2007-01-01

    Using 3-D elastic-plastic FEM, the cold strip rolling process in a 4-high mill was simulated. The elastic deformation of rolls, the plastic deformation of the strip, and the pressure between the work roll and the backup roll were taken into account. The distribution of rolling pressure along the strip width was obtained. Based on the simulation results, the peak value of rolling pressure and the location of the peak were analyzed under different rolling conditions. The effects of the roll bending force and the strip width on the distribution of rolling pressure along the width direction were determined.

  2. Thermal fatigue of high chromium steel rolls

    OpenAIRE

    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...

  3. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  4. Low-Rank Coal Grinding Performance Versus Power Plant Performance

    Energy Technology Data Exchange (ETDEWEB)

    Rajive Ganguli; Sukumar Bandopadhyay

    2008-12-31

    The intent of this project was to demonstrate that Alaskan low-rank coal, which is high in volatile content, need not be ground as fine as bituminous coal (typically low in volatile content) for optimum combustion in power plants. The grind or particle size distribution (PSD), which is quantified by percentage of pulverized coal passing 74 microns (200 mesh), affects the pulverizer throughput in power plants. The finer the grind, the lower the throughput. For a power plant to maintain combustion levels, throughput needs to be high. The problem of particle size is compounded for Alaskan coal since it has a low Hardgrove grindability index (HGI); that is, it is difficult to grind. If the thesis of this project is demonstrated, then Alaskan coal need not be ground to the industry standard, thereby alleviating somewhat the low HGI issue (and, hopefully, furthering the salability of Alaskan coal). This project studied the relationship between PSD and power plant efficiency, emissions, and mill power consumption for low-rank high-volatile-content Alaskan coal. The emissions studied were CO, CO{sub 2}, NO{sub x}, SO{sub 2}, and Hg (only two tests). The tested PSD range was 42 to 81 percent passing 76 microns. Within the tested range, there was very little correlation between PSD and power plant efficiency, CO, NO{sub x}, and SO{sub 2}. Hg emissions were very low and, therefore, did not allow comparison between grind sizes. Mill power consumption was lower for coarser grinds.

  5. The role of abrasion and corrosion in grinding media wear: Annual technical progress report. [Taconite; molybdenite; quartzite

    Energy Technology Data Exchange (ETDEWEB)

    Moore, J.J.; Iwasaki, I.

    1984-06-12

    Aim of this research program is to establish the effect of mill size and batch or continuous operation on the role of corrosive and abrasive wear during mineral grinding operations. Grinding ball wear tests are being conducted on the laboratory, pilot plant and industrial scale. This report gives the results of the first year's work of the two year research program and are discussed under the following headings: Wear Tests in an 8-inch Laboratory Mill (Using Three Different Ball Chemistries for Both Taconite and Molybdenite Ore); Wear Tests in a 36-inch Batch Mill (Using High Carbon Low Alloy Steel Balls with Taconite); Mechanisms of Erosive Wear in Taconite Grinding (Using Mild Steel Balls); The Effect of Slurry Rheology on Grinding Media Wear (Using Mild Steel Balls - Quartzite Combination); and Pilot Plant continuous Grinding Tests (Using High Carbon Low Alloy Steel Balls with Taconite Ore).

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  7. High Performance Grinding and Advanced Cutting Tools

    CERN Document Server

    Jackson, Mark J

    2013-01-01

    High Performance Grinding and Advanced Cutting Tools discusses the fundamentals and advances in high performance grinding processes, and provides a complete overview of newly-developing areas in the field. Topics covered are grinding tool formulation and structure, grinding wheel design and conditioning and applications using high performance grinding wheels. Also included are heat treatment strategies for grinding tools, using grinding tools for high speed applications, laser-based and diamond dressing techniques, high-efficiency deep grinding, VIPER grinding, and new grinding wheels.

  8. Application of AE System in Roll Ring Grinding Control of CNC Machines%声频测量系统在数控辊环磨削工艺中的应用

    Institute of Scientific and Technical Information of China (English)

    王立民

    2011-01-01

    利用声频测量系统,结合西门子数控系统编程语言及PLC功能,在数控辊环磨床中实现测量砂轮与工件的相对距离,并将其自动读取到数控系统中进行数据处理和自动加工.%This paper uses acoustic control system and NC,PLC programming language of SIEMENS CNC system to measure the distance between the grinding wheel and the workpiece and then this value is read automatically,which is sent to CNC system to be processed for NC cycles.

  9. 基于MATLAB的LD-15冷轧管机主传动机构运动分析%Kinematics analysis of the main drive mechanism of LD-15 cold rolling mills based on MATLAB

    Institute of Scientific and Technical Information of China (English)

    强艳丽; 李浙昆; 阎雪峰

    2009-01-01

    为分析机构是否能够满足给定的运动规律和运动空间的要求,必须对机构的运动规律进行研究.本文运用Matlab强大的计算功能,对LD-15冷轧管机主传动机构的运动规律进行求解,并使其结果可视化,从而使机构的运动分析直观、简单、精确,以提高LD-15冷轧管机主传动机构的设计精度和效率.%Research on kinematics law is necessaryto analyze whether the design of mechanism is able to meet the requirements of kinematics law and motion space. The powerful calculating function of MATLAB was used to solve kinematics law of the main drive mechanism of LD-15 cold rolling mills, and the calculation results were visualized. Thus kinematics analysis of the mechanism is visualized, simple and precise, improving the design precision and efficiency of the main drive mechanism of LD-15 cold rolling mills.

  10. Roll Eccentricity Control Using Identified Eccentricity of Top/Bottom Rolls by Roll Force

    Science.gov (United States)

    Imanari, Hiroyuki; Koshinuma, Kazuyoshi

    Roll eccentricity is a periodic disturbance caused by a structure of back up rolls in rolling mills, and it affects product thickness accuracy. It cannot be measured directly by sensors, so it should be identified by measured thickness or measured roll force. When there is a large difference of diameters between top and bottom back up roll, the performance of roll eccentricity control using feedback signals of roll force or thickness has not been so good. Also it has been difficult for the control to be applied from the most head end because it is necessary to identify the roll eccentricity during rolling. A new roll eccentricity control has been developed to improve these disadvantages and to get better performance. The method identifies top and bottom roll eccentricity respectively from one signal of roll force and it can start the control from head end. In this paper the new control method is introduced and actual application results to a hot strip mill are shown.

  11. Design of the Soymilk Mill based on TRIZ Theory

    Directory of Open Access Journals (Sweden)

    Jiang Fan

    2013-05-01

    Full Text Available The soymilk mill is an important food machine, but its volume is too large to be suitable for house using. This study first analyzes some problems in the soymilk mill miniaturization. For these problems, the thinking tools, evolutionary tools and contradiction solving tool of TRIZ theory are used to resolve the conflict in the integration of grinding and boiling and in the keep grinding effect, to tackle the optimization problem in the grinding stria structure and mill plate speed, then the Dwarfs method and substance-field analysis model is used in solving the interference and the conditions water supply problems which are encountered in the design of the global structure and a micro soymilk mill is designed. Finally, the mechanical analysis model about soy granules, soymilk particles in the grinding zone and the computational model of motor starting torque are obtained; they provide the reference data for application of soymilk mill.

  12. Grind hardening process

    CERN Document Server

    Salonitis, Konstantinos

    2015-01-01

    This book presents the grind-hardening process and the main studies published since it was introduced in 1990s.  The modelling of the various aspects of the process, such as the process forces, temperature profile developed, hardness profiles, residual stresses etc. are described in detail. The book is of interest to the research community working with mathematical modeling and optimization of manufacturing processes.

  13. 基于遗传算法的高速轧辊磨床磨头液体动静压轴承的优化设计%Optimization Design of Liquid Hybrid Bearing in Grinding Head of High-speed Roll Grinder Based on Genetic Algorithm

    Institute of Scientific and Technical Information of China (English)

    吴怀超; 令狐克均; 孙官朝; 李哲; 张顺风

    2015-01-01

    The performances of liquid hybrid bearing affect directly grinding performances of the whole roll grinder.Aiming at a kind of adjustable liquid hybrid bearing in grinding head of high-speed roll grinder,its structural characteristics and working principles were analyzed,and its structural di-mensions and working parameters were calculated.Then,the lowest total power loss per unit loading capacity was regarded as an objective function of optimization design,and optimization design of the bearing was performed based on genetic algorithm.Optimization results are as follows:objective func-tion value decreases from 0.0808 to 0.0678,total power loss of the bearing decreases from 766.9W to 642.6W, and power consumption is reduced about 1 6%;moreover,structural dimensions of the bear-ing are reduced,and its stiffness is obviously improved.Therefore,through the optimization design, manufacturing cost of the bearing is reduced,and its comprehensive performances are improved obvi-ously.%液体动静压轴承性能的好坏直接影响着整台磨床的磨削性能。针对一种可调节式的高速轧辊磨床磨头液体动静压轴承,分析了其结构特点和工作原理,并对其结构尺寸和工作参数进行了设计计算。在此基础上,以单位承载量下的总功率损失最小作为优化设计的目标函数,运用遗传算法对该轴承进行了优化设计。优化结果表明:优化后目标函数值从0.0808下降到0.0678,轴承的总功率损失由初始设计的766.9 W 降低为642.6 W,功耗降低约16%,而且轴承的结构尺寸得到减小,其刚度亦得到明显的提高。由此可见,通过优化设计,不仅降低了轴承的制造成本,而且明显改善了轴承的综合性能。

  14. Simulation of type selection for 6-high cold tandem mill based on shape control ability

    Institute of Scientific and Technical Information of China (English)

    PENG Yan; LIU Hong-min; WANG Dong-cheng

    2007-01-01

    A theoretical method for selecting strip rolling mill type that considered shape control ability was established using the figure alteration range that was worked by the alteration track of vector expressing strip's cross section (crown) to express the shape control ability of rolling mill. With the mathematical models and simulation software that were developed by the authors' own models, four types of mills were aimed, including HCM (6-high middle rolls shift type HC (high crown) -mill), HCMW (6-high middle rolls and work rolls shift type HC-mill), UCM (6-high middle rolls shift type HC-mill with middle roll bender) and UCMW (6-high middle rolls and work rolls shift type HC-mill with middle roll bender), and the shape and crown control ability of every mill type was analyzed and compared. An appropriate arrangement mode of tandem mill was brought forward. The results show that UCMW mill is a perfect choice for controlling shape and crown, and the area of control characteristics curve of UCMW (or UCM) is twice than that of HCM, but UCM mill is also a good choice for its simple frame. In other word, the shape and crown controlling ability of UCMW mill is better than that of UCM mill, but the frame of UCM mill is simpler than that of UCMW mill. As for the final type of mill, should be synthetically decided by thinking over fund and equipment technology.

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

    Institute of Scientific and Technical Information of China (English)

    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。

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

    Energy Technology Data Exchange (ETDEWEB)

    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

  17. Computation of Rolling Stand Parameters by Genetic Algorithm

    Directory of Open Access Journals (Sweden)

    František Ďurovský

    2008-05-01

    Full Text Available Mathematical model of rolling process is used at cold mill rolling on tandemmills in metallurgy. The model goal is to analyse rolling process according to process datameasured on the mill and get immeasurable variables necessary for rolling control andoptimal mill pre-set for next rolled coil. The values obtained by model are used asreferences for superimposed technology controllers (thickness, speed, tension, etc. as well.Considering wide steel strip assortment (different initial and final thickness, differenthardness, and fluctuation of tandem mill parameters (change of friction coefficient, workrolls abrasion, temperature fluctuation, etc. the exact analysis of tandem is complicated.The paper deals with an identification of friction coefficient on a single rolling mill standby a genetic algorithm. Mathematical description of tandem mill stand is based on themodified Bland-Ford model. Results are presented in graphical form.

  18. 工作辊凸度对超宽六辊CVC轧机板形调控性能的影响%Influence of Initial Crown of Work Roll on Strip Shape Adjusting Performance of Ultra-Wide 6-h CVC Mill

    Institute of Scientific and Technical Information of China (English)

    黄华贵; 史英钦; 任新意; 杜凤山

    2014-01-01

    Aiming at the 6-h CVC mill of a 2 230 mm cold continuous rolling mill in some domestic plant, the influences of initial crown of work roll on loaded roll gap profile and contact pressure distribution between rolls under the roll bend-ing and shifting were investigated with three-dimensional nonlinear finite element method. The numerical simulation re-sults show that when the work roll profile is parabolic type with initial crown of 0-75μm, the adjusting range of roll crown shifts but its area remains unchanged. And the peak value and unevenness of the contact pressure between rolls are a little improved with increasing the initial crown of work roll, which is beneficial for reducing the roll abrasion. In addition, the adjusting range of roll crown under different strip widths was investigated, and the results show that 6-h CVC has a higher performance in strip shape adjusting for width strip than for narrow strip. It also provides theoretical foundation for the rolling mill type selection in wide thin strip cold rolling.%以国内某2230 mm冷连轧机组六辊CVC轧机为研究对象,利用非线性有限元方法,模拟分析了弯辊和窜辊综合调控下工作辊初始凸度对承载辊缝形状、辊间接触压力分布的影响规律。结果表明,当工作辊采用凸度为0~75μm的抛物线辊型时,轧机承载辊缝凸度调控域发生平移而面积基本不变,但随着工作辊初始凸度增加,辊间接触压力峰值和不均匀度均有所改善,有利于降低轧辊磨损和辊耗。对比分析了不同板宽条件下的辊缝凸度调节域,结果表明,CVC轧机对宽带钢的板形调控能力要明显高于窄带钢,且对二次、四次板形具有较好的抑制作用,为宽薄带钢冷轧机型选择提供了理论依据。

  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»

    Directory of Open Access Journals (Sweden)

    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. The effect of roll with passive segment on the planetary rolling process

    Directory of Open Access Journals (Sweden)

    Qing-Ling Zeng

    2015-03-01

    Full Text Available In three-roll planetary rolling process, there is secondary torsion phenomenon that may lead to rolling instability. This article proposed a new idea to alleviate the secondary torsion phenomenon by dividing the secondary torsion segment out of the roll as an independent and passive one. To study the performance of the roll with passive segment, the three-dimensional finite element models of planetary rolling process using actual roll or new roll with passive segment involving elastic–plastic and thermal–mechanical coupling were established by the software ABAQUS/Explicit, and a series of analysis had been done successfully. The rolling temperature and rolling force of planetary mill were in good agreement with the measured results, which indicated that the finite element method would supply important reference merit for three-dimensional thermo-mechanical simulation of the three-roll planetary rolling process. Comparing the simulation results of the two models, the results indicated that the change in the roll structure had just a little influence on the metal deformation, temperature, and rolling force, but it lessened the secondary torsion deformation effectively and improved the outside roundness of the rolled tube slightly. The research provided a new idea for the roll design of three-roll planetary mill (PSW.

  1. Three-Dimensional Model for Strip Hot Rolling

    Institute of Scientific and Technical Information of China (English)

    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.

  2. Contamination introduced during rock sample powdering. Effects from different mill materials on trace element contamination

    International Nuclear Information System (INIS)

    We examined blanks during powdering processes for thirty-three trace elements using ICP-MS (inductively coupled plasma mass spectrometry). Quartz sand was used as target of powdering with grinding mills of several kinds: an agate hand mill, agate ball mill, Fe hand mill, alumina ceramic hand mill and artificial crystalline quartz hand mill. The results show that the artificial crystalline quartz hand mill is the purest grinder among the analyzed ones. This grinder is suitable for soft rock samples such as limestone. The alumina ceramic hand mill can reduce contamination, except for Cs, W and Pb. The agate hand mill and the agate ball mill introduce contamination whose level is depending on the individual device due to heterogeneity of the natural agate. The Fe hand mill introduces contamination of some si-derophile elements such as Mo and W. The results of this study emphasize careful choice of a grinding mill for sample pulverizing. (author)

  3. Modification of the Filter in the Turbid Circulating Water System at Meishan Steel Hot Rolling Mill and Operating results%梅钢热轧浊循环系统过滤器的改造及运行效果

    Institute of Scientific and Technical Information of China (English)

    邹正东

    2015-01-01

    针对梅钢热轧浊循环系统过滤器出现的问题,进行了详细的分析,并制定了相关改进措施.认为过滤器本体设计、制造存在缺陷,对其改进后,运行稳定性得到了显著提高.%Problems in the high-speed sand filter of the turbid circulating cooling water system at Meishan Steel Hot Rolling Mill were analyzed in detail and corresponding im-provement measures were also drawn up. It was found that the design and manufacture of the filter body had defects and modification was carried out, which has significantly improved op-eration stability.

  4. 冷轧酸性废水处理系统优化措施及建议%Optimization Measures and Recommendations for the Acid Wastewater Treatment System of Cold Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    喻小辉; 毛建刚; 邹金秀

    2015-01-01

    Problems in the operation of the acid wastewater treatment system of Xingang cold rolling mill were introduced and the causes of the problems were analyzed. Issues in system design were pointed out while site management was strengthened to resolve the prob-lems. It was also put forward that wastewater treatment is a system integrating chemical a-gents, equipment and management.%介绍了新钢冷轧厂酸性废水处理系统运行过程中存在的问题,分析了问题产生的原因,在通过现场管理解决问题的同时,指出了系统设计时应注意的问题,并提出了水处理是集药剂、设施设备及管理于一体的体系的观点。

  5. 冷轧厂配套制氢站的工艺选择和工程设计要点%Process Selection and Key Points in Engineering Design for Hydrogen Station in Cold Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    曹海霞; 金网照

    2014-01-01

    Though combustible, explosive and hard to produce and store, hydrogen has unique industrial usages. Based on engineering practices, specific opinions on process selection criterion and key points in design of hydrogen station for cold rolling mill were put forward.%氢气虽然易燃易爆,既不易制取又不易储存,但是却具有独特的工业用途。结合工程实践,对钢铁企业冷轧配套制氢站工艺路线的选择依据提出观点,并对工程设计中要注意的问题提出看法。

  6. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  7. 宝钢1580 热轧自动化系统改造自主集成实践%Self-integration practice of automatic system revamping project of Baosteel 1 580 mm hot rolling mill

    Institute of Scientific and Technical Information of China (English)

    骆德欢

    2015-01-01

    宝山钢铁股份有限公司1580热轧自动化系统改造完全自主设计、自主成套硬件系统、自主调试,改造采用了系统并行切换及接口、高速数据采集、大侧压控制、自动宽度及厚度控制、多级穿带、自动板形控制、卷取温度控制等系列技术,实现了东西方电气技术的高度融合,形成了系统稳定、性能优异、架构合理、接口开放的新的控制系统. 改造后的1580热轧5大精度指标达到了国际先进水平.%The automatic system revamping project of the 1 580 mm hot rolling mill in Baoshan Iron&Steel Co.,Ltd. is totally self-designed,self-manufactured and self-tested. A series of techniques such as system parallel operation and switchover, several kinds of interface, high speed data acquisition, side press control, automatic width and gauge control, multistage threading control, automatic shape control,down coiler temperature control,etc. are used to realize the high degree of integration of Sie-mens and Mitsubishi electrical products and form a new stable,high-performance,reasonable and o-pening control system. The five precision performance indices of the revamped 1 580 mm hot rolling mill reach the international advanced level.

  8. 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

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2012-01-01

    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.

  9. 十八辊冷轧机工作辊侧支承装置受力分析%Force Analysis of WR Side Support Device in 18-H Cold Rolling Mills

    Institute of Scientific and Technical Information of China (English)

    李林

    2016-01-01

    通过对十八辊冷轧机工作辊侧支承装置、工作辊的受力分析,求出侧支承装置受力与轧机主要工作参数之间的函数关系,计算结果能较好地反映设备实际受力情况,可作为十八辊轧机侧支承装置初步设计的依据。%The functional relationship between the forces acting on the side support device and the main technical parameters is set up based on the force analysis on the WR side support device and the work rolls, and can be used as the basis for the design of the WR side support for 18-H cold rolling mills because the calculation result agrees well with the actual force condition of the equipment.

  10. Unsteady-State Grinding Technology (II) Experimental Studies of Grinding Forces and Force Ratio

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    As is known to all, grinding force is one of the most important parameters to evaluate the whole process of grinding. Generally, the grinding force is resolved to three component forces, namely, normal grinding force F n, tangential grinding force F t and a component force acting along the direction of longitudinal feed which is usually neglected because of insignificance. The normal grinding force F n has influence upon surface deformation and roughness of workpiece, while the tangential grinding force ...

  11. 包钢薄板坯连轧主厂房设计%DESIGN OF MAIN BUILDING FOR THE BAR STRIP CONTINUOUS ROLLING MILL IN BAOTOU IRON AND STEEL COMPANY

    Institute of Scientific and Technical Information of China (English)

    田丰; 苏驭虎

    2001-01-01

    连轧主厂房为单层厂房,下柱为钢管混凝土双肢柱,上柱为焊接工字型柱,屋面大梁为焊接工字钢梁.基本柱距12m.设有80/20t吊车3台.厂房内设有7架精轧机及配套的设备基础,地下结构复杂,深迭8m.地面荷载为100kPa,屋面及墙面均采用保温压型钢板.同时,檩条节点做了技术改进.%The main building for the continuous rolling mill is aone-storied factory building. The bottom parts of the columns are steel-pipe concrete battened column. The top parts of the columns are welding Ⅰ-column. The roof beams are welding Ⅰ-steel beam. Columns space basically at 12m. Three cranes (each has a capacity of 80/20t) and 7 finishing mills with matching equipment foundations are equipped inside. There is a complexity in the sub-structure. The depth reaches as 8m. The ground loading is 100kPa. The corrugated sheet steel is used for the wall cladding system and the roof. Certain improvements have been made under the connection points of the purlins.

  12. Design of ADRC for Automatic Position Control Stopping System of Rolling Mill%轧机自动位置控制停车系统ADRC控制器设计

    Institute of Scientific and Technical Information of China (English)

    张瑞成; 陈陆曦

    2015-01-01

    Based on analyzing the damping force ,the elastic force and the roll eccentricity force between the roll and the strip ,a non-linear model of the automatic position control (APC) stopping system of rolling mill is derived .The dynamic analysis shows the APC stopping system has the chaotic characteristics .Based on the characteristics of the APC stopping system ,such as nonlinear and varia-ble parameters ,a two-order active disturbance rejection controller (ADRC) for the automatic position control stopping system is de-signed ,and the simulation is done within uncertainty environment .The simulation results show that the controller has ideal robust-ness to the system chaos and the large load disturbance ,and rapid and smooth control process and high steady precise performances can be implemented .%在考虑轧辊与轧件间的阻尼力、弹性力和轧辊偏心力的基础上 ,建立了一个轧机自动位置控制(A PC ) 停车系统的非线性模型 ,对其动力学特性分析表明该系统具有混沌特性.针对此系统具有非线性、变参数的特点 ,采用自抗扰控制 (ADRC ) 方法设计二阶 ADRC控制器 ,并在不确定性环境下进行仿真研究.结果表明 :ADRC控制器对于系统出现的混沌和大负载干扰具有理想的鲁棒能力 ,其控制过程快速、平滑 ,稳态精度高.

  13. Control of the Processing Parameter of the Raw Meal Grinding System of the MLS 2619 Roll Mill%MLS 2619辊式磨生料粉磨系统工艺参数的控制

    Institute of Scientific and Technical Information of China (English)

    董志强; 段永平; 支俊秉; 文玉柱

    2002-01-01

    介绍了山西新绛威顿水泥有限责任公司1 000t/d预分解窑生产线采用MLS 2619辊式磨粉磨生料的工艺流程、系统主要设备的技术参数以及设备的使用效果.论述了MLS 2619辊式磨粉磨系统运行中工艺参数变化对生产的影响及其控制手段.

  14. Chiral Crystal Growth under Grinding

    OpenAIRE

    Saito, Yukio; Hyuga, Hiroyuki

    2008-01-01

    To study the establishment of homochirality observed in the crystal growth experiment of chiral molecules from a solution under grinding, we extend the lattice gas model of crystal growth as follows. A lattice site can be occupied by a chiral molecule in R or S form, or can be empty. Molecules form homoclusters by nearest neighbor bonds. They change their chirality if they are isolated monomers in the solution. Grinding is incorporated by cutting and shafling the system randomly. It is shown ...

  15. THE CHARACTERIZATION OF GRINDING FORCES

    Directory of Open Access Journals (Sweden)

    E.F. Fielding

    2012-01-01

    Full Text Available Traditionally the grinding process has been a finishing process and the operating parameters and the resuns obtained in this mode are well known. However, wHh the advent of more modern techniques in grinding, there is a need for a greater understanding of the process and in particular a need to be able to predict the forces in grinding. The work reported here is part of an overall programme to study the effects of different dress leads, wheel formulations and metal removal rates on grinding ratios, surlace finish and grinding forces. The work so far has led to the development of empirical relationships based on the various factors in the dressing and grinding operations, these empirical relationships are more easily applied than the relationships developed by other researchers that rely on measurements obtained during testing. The work is now being extended to develop a theoretical derivation on the same principles, the implications of which will be discussed in the paper.

  16. Grinding analysis of Indian coal using response surface methodology

    Institute of Scientific and Technical Information of China (English)

    Twinkle Singh; Aishwarya Awasthi; Pranjal Tripathi; Shina Gautam; Alok Gautam

    2016-01-01

    The present work discusses a systematic approach to model grinding parameters of coal in a ball mill.A three level Box-Behnken design combined with response surface methodology using second order model was applied to the experiments done according to the model requirement.Three parameters ball charge (numbers 10-20),coal content (100-200 g) and the grinding time (4-8 min) were chosen for the experiments as well as for the modeling work.Coal fineness is defined as the d80 (80 % passing size).A quadratic model was developed to show the effect of parameters and their interaction with fineness of the product.Three different sizes (4,1 and 0.65 mm) of Indian coal were used.The model equations for each fraction were developed and different sets of experiments were performed.The predicted values of the fineness of coal were in good agreement with the experimental results (R2 values of d80 varies between 0.97 and 0.99).Fine size of three different coal sizes were obtained with larger ball charge with less grinding time and less solid content.This work represents the efficient use of response surface methodology and the Box-Behnken design use for grinding of Indian coal.

  17. Mathematical model of elastic deformation of cold reduction mill equipped with composite back-up roll%配备组合式支承辊的四辊冷轧机辊系弹性变形数学模型

    Institute of Scientific and Technical Information of China (English)

    董永刚; 苏玉龙; 张岩岩

    2013-01-01

    为求解配备热装组合式支承辊的板带冷轧机辊系弹性变形,将辊套和辊芯进行分段离散,并考虑辊套装配凸度以及辊套与辊芯之间的弹性压扁,根据工作辊、辊套及辊芯之间的变形协调以及力平衡条件,采用影响函数法推导出热装组合式支承辊辊系弹性变形数学模型,并编程求解辊系弹性变形,分析不同弯辊力、窜辊量以及带材宽度对辊系弹性变形的影响.实验结果表明:随着工作辊弯辊力和板宽度的增加,组合式支承辊辊间压扁产生由中间凸到中间凹的变化,且横向分布趋于均匀,随着工作辊窜辊量的增加,辊间压扁出现非对称分布,且非对称程度逐渐增大,窜辊量为100 mm时左右两端的辊间压扁差值超过30 μm;弯辊力变化和窜辊量对组合式支承辊挠度的影响分别不超过0.7 μm/(10×104 N)和0.8 μm/100 mm,带材宽度变化对挠度的影响达1.8 μm/100 mm.%For solving the elastic deformation of the four-high cold strip mill equipped with the composite back-up roll,the roll sleeve and roll mandrel were studied by the discrete segment individually,then the assembled crown of the roll sleeve and the elastic flattening between the roll sleeve and roll mangle were considered,and the model of elastic deformation of cold strip mill was derived by the influence function method according to the deflection concordance principle between the roll sleeve and roll mandrel and working roll and the force equilibrium condition.Moreover,the solution matrix was listed and the solving program was compiled to solve the elastic deformation of composite back-up roll,and the influences of bending force,cross sliding value of work roll and width of strip on the elastic deformation were analyzed by compararing it with that of integrated back-up roll.The research results indicate that the roll flattening distribution along the lateral direction changes from the convex style to the concave style on the

  18. GEOMETRICAL CHARACTERIZATION OF MICRO END MILLING TOOLS

    DEFF Research Database (Denmark)

    Borsetto, Francesca; Bariani, Paolo

    The milling process is one of the most common metal removal operation used in industry. This machining process is well known since the beginning of last century and has experienced, along the years, many improvements of the basic technology, as concerns tools, machine tools, coolants...... carbides the error motion during the grinding wheels do not allow using identical paths for tools having differences in diameter of more than one order of magnitude. Thus grinding paths for micro and mills are simplified in comparison to those for larger tools of similar shape. [1] The aim of the present....../lubricants, milling strategies and controls. Moreover the accuracy of tool geometry directly affects the performance of the milling process influencing the dimensional tolerances of the machined part, the surface topography, the chip formation, the cutting forces and the tool-life. The dimensions of certain...

  19. 热轧塑烧板除尘控制系统改造设计%Transformation Design of the Control System for Sinter-Plate Filter Dedusting at Baosteel’s 2050 Hot Rolling Mill

    Institute of Scientific and Technical Information of China (English)

    冯展国

    2015-01-01

    Since put into operation in 1996, the sinter-plate filter dedusting system at Baosteel’s 2050 hot-rolling line, the first dedusting system of the kind in China, has been a demonstration project in domestic steel industry. But after nearly 20 years of operation, the aged equipment was seriously corroded. Taking the opportunity of annual maintenance in 2014, an overhaul of the dedusting system was carried out and its electrical automation level was upgraded at the same time, which maintained the overall performance of Baosteel’s 2050 hot rolling F4-F7 finishing mill at the leading position in the industry.%作为国内最早投运的同类塑烧板除尘系统,宝钢股份2050热轧厂精轧除尘系统自1996年投产以来,一直作为国内钢铁业的示范工程。但是经过近20年的运行,设备老化锈蚀严重。我们利用2014年年修机会对其进行了整体更新改造,同时提升了电气自动化水平,这使得2050热轧厂F4-F7精轧机除尘整体水平继续保持在行业内的领先地位。

  20. Optimization of Process Variables for Grinding of Ibuprofen using Response Surface Methodology

    Energy Technology Data Exchange (ETDEWEB)

    Sim, Chol-Ho [Sangji University, Wonju (Korea, Republic of)

    2013-12-15

    Ibuprofen, non-steroidal anti-inflammatory drugs; NSAIDs, is a highly crystalline substance with the pharmaceutical properties of poor solubility and low bioavailability. The size reduction of ibuprofen is needed to improve the solubility. The objective of this study is to optimize the grinding condition of ibuprofen. Grinding of ibuprofen was carried out using a planetary mill. Grinding parameters were optimized using Box-Behnken experimental design method. The physical characteristics of ground ibuprofen were investigated for the particle size by particle size analyzer, for the crystal size by X-ray diffraction (XRD), and for the tensile strength by tensile/compression tester. The optimum conditions for the milling of ibuprofen were 290 rpm of the revolution number of mill, 24.6 g of the weight of sample, and 10minutes of grinding time. The measured value of the particle size of ground ibuprofen at these optimum conditions was 13.5 µm. The results showed that the crystal size of ibuprofen was reduced by the planetary milling process. In case the relative density of the tablets formulated of ground ibuprofen was range of 0.85-0.90, the tensile strength of them was range of 12-14 Kg{sub f}/cm{sup 2}.

  1. Efficient Fuel Pretreatment: Simultaneous Torrefaction and Grinding of Biomass

    DEFF Research Database (Denmark)

    Saleh, Suriyati Binti; Hansen, Brian Brun; Jensen, Peter Arendt;

    2013-01-01

    Combining torrefaction and grinding of biomass in one reactor may be an attractive fuel pretreatment process. A combined laboratory torrefaction and ball mill reactor has been constructed for studies of the influence of temperature and residence time on the product yields and particle size...... of the torrefaction process has been evaluated by the relative change in d50, and this method was compared to the Hardgrove grindability index (HGI), showing reasonably similar results. Significant differences in torrefaction behavior have been observed for straw and spruce chips torrefied at 270–330 °C. Torrefaction......, and ash composition, where straw has a higher alkali content. This and other studies indicate that the large difference in the alkali contents of the biomasses is the main cause for the observed difference in torrefaction characteristics. Experiments with separate particle heating and grinding showed...

  2. 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

    Institute of Scientific and Technical Information of China (English)

    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.

  3. 宽带钢热连轧精轧机组成套辊形配置技术研究与应用%Research and Application of One Set Roll Contour Configuration Technology on Finishing Train of Hot Strip Mill

    Institute of Scientific and Technical Information of China (English)

    王晓东; 李飞; 王秋娜; 李本海; 李彬

    2013-01-01

    为了实现热轧宽带钢板形的高精度控制,根据宽带钢热连轧精轧机组上游机架控制凸度与下游机架控制平坦度的特性,在首钢迁钢1580 mm热连轧生产线的精轧机组开发并应用了成套辊形配置技术.在F1机架工作辊采用负凸度辊形,加强带钢轧制过程的对中;在F2到F4机架工作辊应用低轴向力CVC辊形,对带钢进行凸度调控;在F5到F7机架工作辊上采用负凸度辊形,辅以长行程的工作辊周期性窜辊,均匀轧辊磨损,控制带钢的平坦度;在所有机架的支撑辊上采用VCR变接触式辊形,增加机架的横向刚度.采用此辊形配置后,带钢的板形控制精度达95%以上,同时,改善了带钢轧制稳定性,延长了轧制计划长度,实现了一定范围的自由规程轧制.%To realize the high precision control of hot rolled strip, in accordance with the characteristics of finishing train of hot strip mill: crown is controlled in the upper stream stands and flatness is realized in the down stream stands, one set roll contour configuration technology was developed and applied in 1580 mm hot strip mill of Qian' an Iron and Steel Company of Shougang Group. Negative crown contour was employed on work rolls of Fl stand to enhance the alignment during the rolling. CVC (Continuous Variable Crown) with lower thrust force was employed on work rolls from F2 to F4 to carry out the crown control function. Negative crown contour was adopted on work rolls of down stream stands F5 to F7 to control the flatness quality with a combination with the cyclic long stroke work roll shifting for the roll wear dispersing. VCR (Variable Crown Back-up Roll) contour was employed on all back-up rolls of the finishing mill to increase the cross rigidity of roll stack. After this roll contour configuration technology was utilized, strip shape control with a high accuracy of more than 95% and schedule-free rolling within a certain range have been realized, meanwhile

  4. Rolling Manipulation

    Institute of Scientific and Technical Information of China (English)

    SHEN Guo-quan; SHEN Wei-na

    2003-01-01

    @@ Rolling manipulation, one of the characteristic manipulations of traditional Chinese massage, is the main therapeutic manipulation of the rolling-Tuina massage school. It plays an important roll in basic technical teaching of Chinese massage and the clinical treatment. The original meaning of "Rolling" in an ancient Chinese book called Shuowenjiezi () is "turning". This manipulation, founded by Mr. DING Ji-feng, gives the patient a sensation of a ball rolling on the surface of the body. Besides, this manipulation should be performed by hands, so it is named "Rolling".

  5. Influence of Hot Rolling Conditions on the Mechanical Properties of Hot Rolled TRIP Steel

    Institute of Scientific and Technical Information of China (English)

    LI Zhuang; WU Di

    2008-01-01

    Influence of hot rolling conditions on the mechanical properties of hot rolled TRIP steel was investigated.Thermomechanical control processing(TMCP)was conducted by using a laboratory hot rolling mill,in which three different kinds of finish rolling temperatures were applied.The results show that polygonal ferrite,granular bainite and larger amount of stabilized retained anstenite can be obtained by controlled rolling processes.The finer ferrite grain size is produced through the deformation induced transformation during deformation rather than after deformation,which affects the mechanical properties of hot rolled TRIP steel.Mechanical properties increase with decreasing finish rolling temperature due to the stabilization of retained austenite.Ultimate tensile strength(UTS),total elongation(TEL)and the product of ultimate tensile strength and total elongation(UTS×TEL)reaches optimal values(791 MPa,36% and 28 476 MPa%,respectively)whenthe specimen was hot rolled for 50% reduction at finish rolling temperature of 700℃.

  6. 基于反馈BP网络的铝热连轧板凸度预报建模%Predictive Model of Aluminium Strip' s Crown at Hot Tandem Rolling Mill' s Finisher Delivery Based on BP Network

    Institute of Scientific and Technical Information of China (English)

    胡伟

    2011-01-01

    “1+4”铝热连轧机是一个极其复杂的系统,为了精确地建模预报末机架出口处的板凸度,提出利用延时反馈BP网络对板凸度时间序列的预报方法来实现对铝带板凸度的精确建模预测.通过现场实验,采集大量试验数据,并通过数据分析,利用仿真验证该方法的有效性和优越性.%" 1 +4 " aluminum hot tandem rolling mill is a complicated system extremely. In order to predict crown of aluminum strip of the finisher delivery more accurately, this paper puts forward a method of time-lapse loop BP network to forecast the sequencing crown, and the reconfiguration of BP network is trained with LM algorithm. With a large number of test data gathered by on-the-spot experiment and analysis, simulation experiment indicates the predictive precision of relative crown(% ) of strip can reach 0.01% , effectivenes and superiority is proved.

  7. Bruxism (Teeth Grinding or Clenching) (For Parents)

    Science.gov (United States)

    ... Tropical Delight: Melon Smoothie Pregnant? Your Baby's Growth Bruxism (Teeth Grinding or Clenching) KidsHealth > For Parents > Bruxism ( ... called bruxism , which is common in kids. About Bruxism Bruxism is the medical term for the grinding ...

  8. Impact pressure of water in hydraulic descaling during hot strip mill rolling. Netsukan atsuen ni okeru koatsusui datsu scale ji no shototsu atsu

    Energy Technology Data Exchange (ETDEWEB)

    Wada, T.; Oshimi, M. (Nippon Steel Corp., Tokyo (Japan)); Ueda, M. (Hotani Co. Ltd., Osaka (Japan))

    1991-09-01

    Using white Plasticine which shows plastic deformation similar to that of high temperature steel materials, the decrease in the thickness by high pressure water is measured, and impact pressure of water at the time of high pressure water injection is measured with a pressure converter to formulate the relationship with various factors. The thickness loss of Plasticine at the time of high pressure injection is closely correlated with 4 parameters, i.e. water consumption, water pressure, rolling speed, and vertical distance. The thickness loss and impact pressure by hydraulic descaling can be expressed by empirical formulas of {Delta}t = 2000 PV (vH{sup 2}) (cm, correlation coefficient: 0.94) and p = 5.64 PV H{sup 2} (MPa). The impact pressure equation is simple and practical, and agrees well with the result obtained by the equation of Hojas et al. The impact pressure required to remove the primary scale is much higher than that required for the secondary scale, and a careful set up of the conditions is essential to complete the descaling. 13 refs., 7 figs., 7 tabs.

  9. 板带轧机机电传动系统参激非线性扭振鲁棒控制研究%Study on robust control for parametric excitation nonlinear torsional vibration of a strip-rolling mill's mechanical and electrical drive system

    Institute of Scientific and Technical Information of China (English)

    韩东颖; 时培明; 赵东伟

    2016-01-01

    While considering parametric excitation nonlinearity,uncertainty and load torque,the nonlinear torsional vibration dynamic model of a mechanical and electrical transmission system in a strip-rolling mill is built.The problem of the strip-rolling mill's motor-speed robust tracking and non-fragile control of the DC motor is studied.As the nonlinearity of the strip-rolling mill's mechanical and electrical drive system is translated into parameter uncertainty,the sufficient condition that lets the system attain quadratic stability and outside-disturbance attenuation is obtained using H∞theory,Lyapunov stability theory and the LMI method.In order to achieve the given speed-signal tracking and non-fragile control,a feedforward and compensatory controller is designed.The results of the real strip-rolling mill's simulation example verify the effectiveness of the proposed method,and the non-fragility of the controller is reflected as the controller's parameter robustness.This means that the effect of the torsional vibration non-fragile control of the strip-rolling mill's mechanical and electrical drive system can be fulfilled by choosing the parameters of the controller directly.%建立了含参激非线性、不确定性、负载转矩的轧机机电传动系统扭振动力学模型,研究了板带轧机电机速度鲁棒跟踪非脆弱控制问题。将板带轧机机电传动系统的非线性按参数不确定性处理,通过 H∞理论、Lyapunov 稳定性理论和线性矩阵不等式(LMI)方法得到了通过状态反馈使得系统满足二次稳定、抑制外界干扰的充分条件;为了实现给定速度信号跟踪非脆弱控制,设计了前馈补偿器。轧机实例仿真结果验证了方法的有效性,并发现控制器的非脆弱性表现为控制器参数的鲁棒性,即可以通过控制器参数的直接选取达到板带轧机机电传动系统扭振非脆弱控制效果。

  10. Unsteady-State Grinding Technology (I) Theoretical Generalization and Research on Grinding Mechanism

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In conventional grinding theory, it is obvious that there must be a very high hardness difference between grains of the grinding wheel and workpieces. The best grinding wheels are those giving the lowest "natural limiting surface roughness" while cutting at appreciable plunge velocities. With the development of new materials and new machining processes, conventional theories of grinding techniques are no longer suitable to explain many phenomena in the course of grinding procedures. In dealing with precisio...

  11. Ultrasonic precision optical grinding technology

    Science.gov (United States)

    Cahill, Michael J.; Bechtold, Michael J.; Fess, Edward; Wolfs, Frank L.; Bechtold, Rob

    2015-10-01

    As optical geometries become more precise and complex and a wider range of materials are used, the processes used for manufacturing become more critical. As the preparatory stage for polishing, this is especially true for grinding. Slow processing speeds, accelerated tool wear, and poor surface quality are often detriments in manufacturing glass and hard ceramics. The quality of the ground surface greatly influences the polishing process and the resulting finished product. Through extensive research and development, OptiPro Systems has introduced an ultrasonic assisted grinding technology, OptiSonic, which has numerous advantages over traditional grinding processes. OptiSonic utilizes a custom tool holder designed to produce oscillations in line with the rotating spindle. A newly developed software package called IntelliSonic is integral to this platform. IntelliSonic automatically characterizes the tool and continuously optimizes the output frequency for optimal cutting while in contact with the part. This helps maintain a highly consistent process under changing load conditions for a more accurate surface. Utilizing a wide variety of instruments, test have proven to show a reduction in tool wear and increase in surface quality while allowing processing speeds to be increased. OptiSonic has proven to be an enabling technology to overcome the difficulties seen in grinding of glass and hard optical ceramics. OptiSonic has demonstrated numerous advantages over the standard CNC grinding process. Advantages are evident in reduced tool wear, better surface quality, and reduced cycle times due to increased feed rates. These benefits can be seen over numerous applications within the precision optics industry.

  12. THERMAL STUDY ON THE GRINDING OF GRANITE WITH SUPERABRASIVE TOOLS

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    In the present paer, a thermal study was conducted for the grinding of granite with diamond tools. Three types of grinding-straight surface grinding, deep grinding(circular sawing), and vertical spindle grinding-were studied. Some surface grinding tests were also conducted using a CBN(cubic boron nitride) wheel. Temperature distributions on the workpiece surface were measured using a foil thermocouple and the energy partition to the workpiece was estimated using a temperature matching method. The temperature for CBN surface grinding was found to be much higher than for diamond grinding. Energy partitions to the granite were 30%~36% for CBN surface grinding, 25%~32% for diamond surface grinding, about 53% for vertical spindle grinding, and 5.5%~9% for diamond deep grinding. The low energy partition value in deep grinding also suggested that more of the heat generated by grinding in this case can be conducted to the grinding tool and promote tool wear.

  13. Comparison between vitrified bond and resin bond diamond grinding wheel in grinding PDC

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaofu; Zhang Hongxia; Lu Anxian; Mark J. Jackson

    2008-01-01

    In this research, the advantages and disadvantages of the cylindrical grinding process of Polycrystalline Diamond Compacts (short for PDC) with vitrified and resin bond diamond grinding wheel are compared. The research results show that the vitrified bond diamond grinding wheels, which use Ti-coated diamond grains as abrasive and glass ceramic as bond, have many advantages in grinding PDC . Compared with resin diamond grinding wheel,vitrified bond wheels lead to 35% grinding cost reduced, 40% grinding time of each PDC saved, and the size precision of PDC improved (from ±0.03mm to ±0.01mm). When grinding feed is <0.10 mm, the grinding ratio increases with increased grinding feed. However, when the grinding feed exceeds 0.10 mm, the grinding radio decreases rapidly with the increasing of grinding feed. The disadvantage of this kind of grinding wheel is that the brightness of the ground PDC cylinder is not as shining as that processed by resin bond diamond grinding wheel.

  14. Surface grinding of intermetallic titanium aluminides

    CERN Document Server

    Gröning, Holger Andreas

    2014-01-01

    A deductive kinematic model of creep-feed and speed-stroke grinding processes is developed to identify possibilities to reduce the energy introduced into the workpiece. By computer tomography analysis and tactile measurements of the grinding wheel the pore volume and the static cutting edge number are determined and included in the model. Based on the kinematic model and the grinding wheel characteristics an analytical evaluation of the specific grinding energy for speed-stroke and creep-feed grinding is carried out. The deducted process design is evaluated in experimental investigations. The

  15. Force Characteristics in Continuous Path Controlled Crankpin Grinding

    Institute of Scientific and Technical Information of China (English)

    ZHANG Manchao; YAO Zhenqiang

    2015-01-01

    Recent research on the grinding force involved in cylindrical plunge grinding has focused mainly on steady-state conditions. Unlike in conventional external cylindrical plunge grinding, the conditions between the grinding wheel and the crankpin change periodically in path controlled grinding because of the eccentricity of the crankpin and the constant rotational speed of the crankshaft. The objective of this study is to investigate the effects of various grinding conditions on the characteristics of the grinding force during continuous path controlled grinding. Path controlled plunge grinding is conducted at a constant rotational speed using a cubic boron nitride (CBN) wheel. The grinding force is determined by measuring the torque. The experimental results show that the force and torque vary sinusoidally during dry grinding and load grinding. The variations in the results reveal that the resultant grinding force and torque decrease with higher grinding speeds and increase with higher peripheral speeds of the pin and higher grinding depths. In path controlled grinding, unlike in conventional external cylindrical plunge grinding, the axial grinding force cannot be disregarded. The speeds and speed ratios of the workpiece and wheel are also analyzed, and the analysis results show that up-grinding and down-grinding occur during the grinding process. This paper proposes a method for describing the force behavior under varied process conditions during continuous path controlled grinding, which provides a beneficial reference for describing the material removal mechanism and for optimizing continuous controlled crankpin grinding.

  16. Technological improvements in wire rod mills

    Energy Technology Data Exchange (ETDEWEB)

    Lestani, M.

    1996-07-01

    The paper deals with the latest rolling technologies and hi-tech equipment developed by Danieli-mogardshammar to ensure top performance of modern wire rod mills. In particular, a high reduction sizing mill, a twin module fast finishing block and a high speed cropping shear are presented. (authors)

  17. The effects of pf grind quality on coal burnout in a 1 MW combustion test facility

    Energy Technology Data Exchange (ETDEWEB)

    Richelieu Barranco; Michael Colechin; Michael Cloke; Will Gibb; Edward Lester [University of Nottingham, Nottingham (United Kingdom). School of Chemical, Environmental and Mining Engineering, Nottingham Fuel and Energy Centre

    2006-05-15

    A study was carried out to determine the effect of pf particle size distribution on coal burnout propensity in a 1 MW pulverised fuel burner. The specific aim of the work was to assess the improvement in combustion performance achievable by retrofitting commercially available high performance static or dynamic classifiers to existing plants. Two coals were used and were selected as representative of extremes in fuel characteristics experienced by coal importing utilities in Europe. Each coal was fired in the unit at a range of grind sizes to determine the overall impact of a variable performance from a mill. The levels of unburnt carbon in the resultant flyashes for the two coals showed significantly different behaviour. For the higher volatile coal, the unburnt carbon was found to be insensitive to grind quality. However, the coarser grinds of the other coal produced significantly lower unburnt carbon than expected when compared with the finest grinds. Generally the results indicate that the installation of improved classification technology, leading to a finer product, will help to lower unburnt carbon levels. Nevertheless, further work will be necessary to establish the levels of diminishing returns for grind size, burnout performance and grind costs. 21 refs., 4 figs., 4 tabs.

  18. Plate Shape Control Theory and Experiment for 20-high Mill

    Institute of Scientific and Technical Information of China (English)

    Zheng-wen YUAN; Hong XIAO

    2015-01-01

    Roll lfattening theory is an important part of plate shape control theories for 20-high mill. In order to improve the ac-curacy of roll lfattening calculation for 20-high mill, a new and more accurate roll lfattening model was proposed. In this model, the roll barrel was considered as a ifnite length semi-inifnite body. Based on the boundary integral equation method, the numerical solution of the ifnite length semi-inifnite body under the distributed force was obtained and an accurate roll lfattening model was established. Coupled with roll bending model and strip plastic deformation, a new and more accurate plate control model for 20-high mill was established. Moreover, the effects of the ifrst intermediate roll taper angle and taper length were analyzed. The ten-sion distribution calculated by analytical model was consistent with the experimental results.

  19. Effect of ball milling materials and methods on powder processing of Bi2223 superconductors

    Science.gov (United States)

    Yavuz, M.; Maeda, H.; Vance, L.; Liu, H. K.; Dou, S. X.

    1998-10-01

    Various milling systems consisting of agate and polypropylene grinding containers, agate and YSZ balls, and dry and wet milling were used in planetary ball-milling and YSZ balls and YSZ container were used in wet and dry attrition milling. The differently milled powders were then evaluated by measurements of particle size, surface area, porosity, size distribution and chemical analysis of the Si, Zr and C contents. The results show that dry milling is much more efficient for particle size reduction in planetary milling than wet milling, whereas wet milling and dry milling gave quite similar results in attrition milling. Meanwhile 0953-2048/11/10/056/img6 contamination was found in powder milled with an agate container with agate balls. Some C contamination from the polypropylene container was detected after milling, but negligible Zr from YSZ balls and C from the grinding carrier (hexane). It was found that after 1 h milling in the planetary mill fracture mechanisms transform from the elastic to the plastic region. Therefore, further milling is not very effective. It was also shown that the Bi2212 phase decomposes into several non-superconducting oxides such as 0953-2048/11/10/056/img7, CuO and a main amorphous phase after extensive dry milling.

  20. Spray Rolling Aluminum Strip for Transportation Applications

    Energy Technology Data Exchange (ETDEWEB)

    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

  1. Design & Manufacture of Compound Liner for Rolling Mill Housing & Bearing Chock%轧机牌坊和轴承座复合衬板设计与制造

    Institute of Scientific and Technical Information of China (English)

    吴迪; 姚书典

    2014-01-01

    描述了轧机牌坊和轧辊轴承轴衬板设计与制造,重点考察了炸药量、基材中间镀层和表面粗糙度对爆炸焊接复合的影响。研究结果显示,推导并验证的经验公式一定程度上能指导实际生产;基板表面研磨后镀铬或镀镍对复合率、结合界面质量均未发现显著的效果;剪切强度随表面粗糙度呈极小值变化,极小点的粗糙度约0.8μm,在极值点左侧,剪切强度随粗糙度减小而急剧增大,而在极值点的右侧,剪切强度随粗糙度加大而略有平缓的增大趋势。%The design & manufacture of lineres for rolling mill housing & bearing chock is described. The impact factor such as explosive materials quantity,middle coating & surface roughness were investigated re-spectively which is effect on the explosive welding.The results reveal that the empirical formula of explosive ma-terials quantity can be used satisfactorily to guide actual production to some extent;the middle coating as chro-mium & nickel plated made no difference,there was a minimal value in shear strength at about surface rough-ness 0.8μm,which the mild increase in the right side of the extreme value point,however,the sharp increase in the left side of the extreme value point.

  2. Pre-evaluation of occupational hazards in the relocation and expansion project of a steel rolling mill%某轧钢厂搬迁扩建项目职业病危害预评价

    Institute of Scientific and Technical Information of China (English)

    王梅; 张鹏飞; 王晓波; 董秀; 王淳; 闫雅君; 赵金凤

    2012-01-01

    [ Objective ] To identify, analyze and evaluate the occupational hazard factors in the relocation and expansion project of a steel rolling mill, protect the health of workers. [Methods]The methods of analogy, checklist and comprehensive analysis were applied for the evaluation. [Results]The main occupational hazard factors during the production process in this project were fluorite mixed dust, welding fumes, other dust, carbon monoxide, sulfur dioxide, manganese and its compounds, nitrogen oxides, ozone, paraffin smoke, noise, high temperature, low temperature, electromagnetic radiation and ultraviolet radiation. [ Conclusion ] The possible occupational hazards during the production process of this project can be prevented, so the project is feasible from the view of occupational hygiene.%目的 识别、分析、评价某轧钢厂搬迁扩建项目产生的职业病危害因素,保护劳动者的身体健康.方法 采用类比法、检查表法、综合分析法进行评价.结果 该项目在生产过程中可能产生的职业病危害因素主要有萤石混合性粉尘、电焊烟尘、其他粉尘、一氧化碳、二氧化硫、锰及其化合物、氮氧化物、臭氧、石腊烟、噪声、高温、低温、电磁辐射和紫外辐射.结论 该项目在生产过程中可能产生的职业病危害是可以预防的,从职业卫生角度分析该项目可以实施.

  3. Rolling Stonesi kinokontsert kannab toorest rokiväge / Maris Meiessaar

    Index Scriptorium Estoniae

    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

  4. Influence of quartz particles on wear in vertical roller mills

    DEFF Research Database (Denmark)

    Jensen, Lucas R.D.; Friis, Henrik; Fundal, Erling;

    2010-01-01

    The standard closed circuit comminution process commonly employed in industrial vertical roller mills has been analyzed to determine the influence of typical abrasive minerals on wear rates. With the main focus on raw mixes used in cement plants, synthetic mixtures imitating were prepared. Using...... in an increased concentration of abrasive particles in the grinding bed ðR2 > 0:99Þ. The present study shows that the quartz concentration in the grinding bed is determining the wear rate....

  5. New Vitrified Bond Diamond Grinding Wheel for Grinding the Cylinder of Polycrystalline Diamond Compacts

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In this work, a kind of new vitrified bond based on Li2O-Al2O3-SiO2 glass ceramics was used to bond the diamond grains, which is made into grinding wheel and the cylindrical grinding process of polycrystalline diamond compacts (PDCs) by using the new vitrified bond diamond grinding wheel was discussed. Several factors which influence the properties of grinding wheel such as amount of vitrified bond and the kinds and amount of stuff in grinding wheel were also investigated. It was found that the new vitrified bond can firmly combine diamond grains, when there are only diamonds and vitrified bond in the structure of grinding wheel, the longevity of the grinding wheel is about 2.5-3 times as that of resin bond grinding wheel for processing PDCs. The grinding size precision of PDCs can be improved from ±0.03 mm to ±0.01 mm because of larger Young's modulus of vitrified bond than resin bond. The grinding time of a PDC product can be 1.75-2.0 min from 3.25-3.5 min, so this kind of grinding wheel can save much time for processing PDCs. Also, there is hardly noise when using this new vitrified bond diamond grinding wheel to process PDCs. The amount of vitrified bond in grinding wheel influences the longevity of grinding wheel. When the size of diamond grains is 90-107 μm, the optimal amount of vitrified bond in grinding wheel is 21% (wt pet). When the amount of vitrified bond exceeds 21%, there are many pores in grinding block, which will decrease the longevity of grinding wheel. The existence of addition stuff such as Al2O3 or SiC can reduce the longevity of grinding wheel.

  6. Wedge - rolls rolling of hollowed parts

    Directory of Open Access Journals (Sweden)

    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.

  7. Influence of suspension stability on wet grinding for production of mineral nanoparticles

    Institute of Scientific and Technical Information of China (English)

    S. Sakthivel; Venkatesan V. Krishnan; Pitchumani

    2008-01-01

    Grinding behavior of nanoparticles in an attritor mill and the minimum achievable particle size are strongly influenced by the suspension stability. In the present work, suspension stability (i.e. (-potential) of nanoparticles was studied by measuring pH as a function of grinding time in the wet milling process. It was found that after a certain time in an attritor mill, there is no further size reduction and the average product particle size increases monotonically. One of the reasons is that the production of submicron particles leads to more particle-particle interactions and consequently pH of the suspension decreases with grinding time. Usually pH value is related to suspension stability and it can be enhanced by addition of NaOH solution. The maximum negative (-potential of -51.2 mV was obtained at pH of 12 for silica. The higher the (-potential with the same polarity, higher will be the electrostatic repulsion between the particles. Hence, the maximum electrostatic repulsion force was maintained by the adjustment of pH value in wet milling. The experiments were conducted at different pH conditions which were maintained constant throughout the experiments and nanosized particles were obtained consequently.

  8. Synthesis and characterization of silicon carbide by reaction milling in a dual-drive planetary mill

    International Nuclear Information System (INIS)

    The formation of silicon carbide from elemental silicon and graphite powder by reaction milling in a specially designed dual-drive planetary mill is reported. The phase evolutions, particle size distribution, and morphology of particles during milling are studied during a 40-h grinding period. X-ray diffraction study indicates complete conversion of silicon and graphite to silicon carbide. The crystallite size varies from 150 nm from the start to 10 nm after 40 h of milling. The lattice strain increases with milling up to about 20 h when SiC forms and subsequently with the formation of SiC it is reduced. Al-SiC composites are prepared by mixing Al with 40 h milled final SiC powder and sintered in an inert atmosphere. The composites show excellent compatibility between Al and SiC particles, no voids or cracks are present

  9. CREATION OF INFORMATION-ANALYTICAL SYSTEM OF CONTINUOUS GRADED ROLLING

    Directory of Open Access Journals (Sweden)

    S. M. Zhuchkov

    2009-01-01

    Full Text Available The computer means allowing to ca n y out of analytical research of process continuous rolling on mills with the various technological circuits of manufacture is created. With the help of the developed information-analytical system continuous rolling, the urgent tasks of manufacture of hire on rolling mills, in particular, decrease of consumption of power resources can be successfully decided during continuous rolling at the expense of optimization existing or development of the new technological circuits of manufacture of hire.

  10. Study on corrosive grinding of gears

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Careful grinding or honing is usually required in machining of gears in order to improvethe machining quality of gear surface. Thus several grinding additives were used to formulate syn-thetic grinding lubricants similar to superior running-in lubricants. Experimental results show thatthe tooth surface of the produced oblique gear and steel worm becomes extremely smooth aftergrinding at a certain load for about a half to one hour. Especially, the gear surface finished withspecially formulated grinding lubricant reaches mirror-like smoothness. The quality of the geartooth can be improved by corrosive grinding, while the corrosive grinding time can be controlled byadjusting the quantity of the corrosive additives and the speed and load of the gears.

  11. Model Predictive Control for an Industrial SAG Mill

    DEFF Research Database (Denmark)

    Ohan, Valeriu; Steinke, Florian; Metzger, Michael;

    2012-01-01

    We discuss Model Predictive Control (MPC) based on ARX models and a simple lower order disturbance model. The advantage of this MPC formulation is that it has few tuning parameters and is based on an ARX prediction model that can readily be identied using standard technologies from system...... identication. When applied to MIMO systems we call this controller a MIMO-ARX based MPC. We use an industrial Semi-Autogenous Grinding (SAG) mill to illustrate the performance of this controller. SAG mills are the primary units in a grinding chain and also the most power consuming units. Therefore, improved...

  12. 29 CFR 1910.216 - Mills and calenders in the rubber and plastics industries.

    Science.gov (United States)

    2010-07-01

    ... in accordance with this section and Subpart S of this part. (4) Mill roll heights. All new mill...) Mill safety controls—(1) Safety trip control. A safety trip control shall be provided in front and in back of each mill. It shall be accessible and shall operate readily on contact. The safety trip...

  13. Specific grinding energy and surface roughness of nanoparticle jet minimum quantity lubrication in grinding

    Directory of Open Access Journals (Sweden)

    Zhang Dongkun

    2015-04-01

    Full Text Available Nanoparticles with the anti-wear and friction reducing features were applied as cooling lubricant in the grinding fluid. Dry grinding, flood grinding, minimal quantity of lubrication (MQL, and nanoparticle jet MQL were used in the grinding experiments. The specific grinding energy of dry grinding, flood grinding and MQL were 84, 29.8, 45.5 J/mm3, respectively. The specific grinding energy significantly decreased to 32.7 J/mm3 in nanoparticle MQL. Compared with dry grinding, the surface roughness values of flood grinding, MQL, and nanoparticle jet MQL were significantly reduced with the surface topography profile values reduced by 11%, 2.5%, and 10%, respectively, and the ten point height of microcosmic unflatness values reduced by 1.5%, 0.5%, and 1.3%, respectively. These results verified the satisfactory lubrication effects of nanoparticle MQL. MoS2, carbon nanotube (CNT, and ZrO2 nanoparticles were also added in the grinding fluid of nanoparticle jet MQL to analyze their grinding surface lubrication effects. The specific grinding energy of MoS2 nanoparticle was only 32.7 J/mm3, which was 8.22% and 10.39% lower than those of the other two nanoparticles. Moreover, the surface roughness of workpiece was also smaller with MoS2 nanoparticle, which indicated its remarkable lubrication effects. Furthermore, the role of MoS2 particles in the grinding surface lubrication at different nanoparticle volume concentrations was analyzed. MoS2 volume concentrations of 1%, 2%, and 3% were used. Experimental results revealed that the specific grinding energy and the workpiece surface roughness initially increased and then decreased as MoS2 nanoparticle volume concentration increased. Satisfactory grinding surface lubrication effects were obtained with 2% MoS2 nanoparticle volume concentration.

  14. Changeing of fly ash leachability after grinding

    Science.gov (United States)

    Lakatos, J.; Szabo, R.; Racz, A.; Banhidi, O.; Mucsi, G.

    2016-04-01

    Effect of grinding on the reactivity of fly ash used for geopolymer production was tested. Extraction technique using different alkaline and acidic solutions were used for detect the change of the solubility of elements due to the physical and mechano-chemical transformation of minerals in function of grinding time. Both the extraction with alkaline and acidic solution have detected improvement in solubility in function of grinding time. The enhancement in alkaline solution was approx. 100% in case of Si and Al. The acidic medium able to dissolve the fly ash higher manner than the alkaline, therefore the effect of grinding was found less pronounced.

  15. Study on the Friction Coefficient in Grinding

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The friction between the abrasive grains and workpi ec e is a crutial factor determining the main grinding output. Few studies have bee n carried out investigating the values of the friction coefficient in grinding, due to the difficulty of direct measurement. In this paper, a mathematical model of the friction coefficient in grinding has been established with the aid of a new grinding parameter C ge, which has close relations to wheel wear rate Z s, metal removal rate Z w, specific energy u and gr...

  16. Polymorphic coupling vibration of a mill main drive system induced by synergy effect of motor current harmonics and rolling force ones%电流谐波与轧制力谐波协同诱发主传动多态耦合振动研究

    Institute of Scientific and Technical Information of China (English)

    张义方; 闫晓强; 凌启辉

    2014-01-01

    现代大型热连轧机是一种复杂机电系统,轧机振动问题是影响轧机生产稳定的严重问题。利用扭矩遥测系统测试轧机机械传动系统扭振发现轧机主传动扭振波形及频谱中存在典型的强或弱两种振动特征。同时发现轧机在轧制过程中电机电流和轧制力存在谐波,当谐波与传动系统固有频率接近时将诱发较大的振动。为研究其机理,利用仿真技术求解了轧机主传动扭振与电流谐波和轧制力谐波激励的相关性。研究表明:随着谐波激励特征的变化,主传动扭振呈现多态强弱变化,从而为抑制轧机耦合振动提供理论依据。%Large modern hot strip mill is a complex electromechanical system.Vibration of a rolling mill is a serious problem affecting the stability of production.By using a torque telemetry system to measure the torsional vibration of the main mechanical drive system,it was shown that two typical characteristics of strong or weak vibration exist in the waveform and spectrum of the torsional vibration;meanwhile,there are harmonics of motor current and rolling force during the rolling mill’s production;when the harmonic frequencies are close to the natural frequencies of the main drive system, heavier torsional vibrations are induced in the mill main drive system.For the study of their mechanism,using computer simulation,the correlation between the main drive system torsional vibration and the harmonic excitations of motor current and rolling force was solved.The study results showed that with the changes in harmonics excitations,the torsional vibration of the main drive system reveals a polymorphic strong or weak variation.The results provided a theoretical foundation for suppressing rolling mills’coupling vibration.

  17. Using of fluidized-bed jet mill to a super fine comminution of steel composite

    Directory of Open Access Journals (Sweden)

    D. Urbaniak

    2015-01-01

    Full Text Available In many industries the demand for very fine material increases. In the metallurgical industry, for example, there is increasing use of the production of high density metal elements with the use of metallurgical powder composites. The use of powder composites requires prior their grinding. Unfortunately, the very fine grinding is not an easy process. The using for this purpose fluidized-bed jet mill was proposed in the paper. The attempts of grinding of metallurgical powder were carried out in the fluidized-bed jet mill. After the experiment analyses of particle size distribution of grinding products were performed. The results are presented in graphs. Analyses of the obtained results concluded that the grinding of very fine metallurgical composite is possible and produces positive results.

  18. Improved coal grinding and fuel flow control in thermal power plants

    DEFF Research Database (Denmark)

    Niemczyk, Piotr; Bendtsen, Jan Dimon

    2011-01-01

    A novel controller for coal circulation and pulverized coal flow in a coal mill is proposed. The design is based on optimal control theory for bilinear systems with additional integral action. The states are estimated from the grinding power consumption and the amount of coal accumulated...... in the mill by employing a special variant of a Luenberger observer. The controller uses the rotating classifier to improve the dynamical performance of the overall system. The proposed controller is compared with a PID-type controller with available pulverized coal flow measurements under nominal conditions...... as well as when parameter uncertainties and noise are present. The proposed controller lowers the grinding power consumption while in most cases exhibiting superior performance in comparison with the PID controller....

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

    Institute of Scientific and Technical Information of China (English)

    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.

  20. En route to a multi-model scheme for clinker comminution with chemical grinding aids

    CERN Document Server

    Mishra, R K; Carmona, H A; Wittel, F K; Sawley, M L; Weibel, M; Gallucci, E; Herrmann, H J; Heinz, H; Flatt, R J

    2015-01-01

    We present a multi-model simulation approach, targeted at understanding the behavior of comminution and the effect of grinding aids (GAs) in industrial cement mills. On the atomistic scale we use Molecular Dynamics (MD) simulations with validated force field models to quantify elastic and structural properties, cleavage energies as well as the organic interactions with mineral surfaces. Simulations based on the Discrete Element Method (DEM) are used to integrate the information gained from MD simulations into the clinker particle behavior at larger scales. Computed impact energy distributions from DEM mill simulations can serve as a link between large-scale industrial and laboratory sized mills. They also provide the required input for particle impact fragmentation models. Such a multi-scale, multi-model methodology paves the way for a structured approach to the design of chemical additives aimed at improving mill performance.

  1. Manufacturing processes 2 grinding, honing, lapping

    CERN Document Server

    Klocke, Fritz

    2009-01-01

    Presents a view of the most common machining and non-machining manufacturing processes. This volume describes the characteristics of abrasive tools, their design and manufacturing, followed by the fundamentals of grinding fluids. It also discusses grinding of different materials (steel, cast iron, hard and brittle materials, nickel and titanium).

  2. Optimization of grinding in reverse flotation for bauxite

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The reverse flotation for desiliconization form bauxite is better than direct flotation, and the grinding before flotation affects the flotation indexes to some extend. The grinding dynamic equation of bauxite based on the data of grinding experiment of diasporic bauxite was derived. The calculated value of the equation is identical with the experiment value. Further the grinding dynamic equation of intermediate grain size range suitable for reversal flotation has also been derived. The grinding time required could be calculated when the mass fraction of intermediate size grain is maximum. The formulation of grinding dynamic equation considerably simplified the grinding experiment, optimized the grinding process.

  3. Precision diamond grinding of ceramics and glass

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S.; Paul, H.; Scattergood, R.O.

    1988-12-01

    A new research initiative will be undertaken to investigate the effect of machine parameters and material properties on precision diamond grinding of ceramics and glass. The critical grinding depth to initiate the plastic flow-to-brittle fracture regime will be directly measured using plunge-grind tests. This information will be correlated with machine parameters such as wheel bonding and diamond grain size. Multiaxis grinding tests will then be made to provide data more closely coupled with production technology. One important aspect of the material property studies involves measuring fracture toughness at the very short crack sizes commensurate with grinding damage. Short crack toughness value`s can be much less than the long-crack toughness values measured in conventional fracture tests.

  4. Vertical Vibration of Moving Strip in Rolling Process Based on Beam Theory

    Institute of Scientific and Technical Information of China (English)

    SUN Jianliang; PENG Yan; LIU Hongmin; JIANG Guangbiao; JIANG Guangbiao

    2009-01-01

    The shape and thickness qualities of strip are influenced by the vibration of rolling mill. At present, the researches on the vibration of rolling mill are mainly the vertical vibration and torsional vibration of single stand mill, the study on the vibration of tandem rolling mill is rare. For the vibration of tandem rolling mill, the key problem is the vibration of the moving strip between stands. In this paper, considering the dynamic of moving strip and rolling theory, the vertical vibration of moving strip in the rolling process was proposed. Take the moving strip between the two mills of tandem rolling mill in the rolling process as subject investigated, according to the theory of moving beam, the vertical vibration model of moving strip in the rolling process was established. The partial differential equation was discretized by Galerkin truncation method. The natural frequency and stability of the moving strip were investigated and the numerical simulation in time domain was made. Simulation results show that, the natural frequency was strongly influenced by the rolling velocity and tension. With increasing of the rolling velocity, the first three natural frequencies decrease, the fourth natural frequency increases;with increasing of the unit tension, when the rolling velocity is high and low, respectively, the low order dimensionless natural frequency gradually decreases and increases, respectively. According to the stability of moving strip, the critical speed was determined, and the matching relationship of the tension and rolling velocity was also determined. This model can be used to study the stability of moving strip, improve the quality of strip and develop new rolling technology from the aspect of dynamics.

  5. Crystalline silica dust and respirable particulate matter during indoor concrete grinding - wet grinding and ventilated grinding compared with uncontrolled conventional grinding.

    Science.gov (United States)

    Akbar-Khanzadeh, Farhang; Milz, Sheryl; Ames, April; Susi, Pamela P; Bisesi, Michael; Khuder, Sadik A; Akbar-Khanzadeh, Mahboubeh

    2007-10-01

    The effectiveness of wet grinding (wet dust reduction method) and ventilated grinding (local exhaust ventilation method, LEV) in reducing the levels of respirable crystalline silica dust (quartz) and respirable suspended particulate matter (RSP) were compared with that of uncontrolled (no dust reduction method) conventional grinding. A field laboratory was set up to simulate concrete surface grinding using hand-held angle grinders in an enclosed workplace. A total of 34 personal samples (16 pairs side-by-side and 2 singles) and 5 background air samples were collected during 18 concrete grinding sessions ranging from 15-93 min. General ventilation had no statistically significant effect on operator's exposure to dust. Overall, the arithmetic mean concentrations of respirable crystalline silica dust and RSP in personal air samples during: (i) five sessions of uncontrolled conventional grinding were respectively 61.7 and 611 mg/m(3) (ii) seven sessions of wet grinding were 0.896 and 11.9 mg/m(3) and (iii) six sessions of LEV grinding were 0.155 and 1.99 mg/m(3). Uncontrolled conventional grinding generated relatively high levels of respirable silica dust and proportionally high levels of RSP. Wet grinding was effective in reducing the geometric mean concentrations of respirable silica dust 98.2% and RSP 97.6%. LEV grinding was even more effective and reduced the geometric mean concentrations of respirable silica dust 99.7% and RSP 99.6%. Nevertheless, the average level of respirable silica dust (i) during wet grinding was 0.959 mg/m(3) (38 times the American Conference of Governmental Industrial Hygienists [ACGIH] threshold limit value [TLV] of 0.025 mg/m(3)) and (ii) during LEV grinding was 0.155 mg/m(3) (6 times the ACGIH TLV). Further studies are needed to examine the effectiveness of a greater variety of models, types, and sizes of grinders on different types of cement in different positions and also to test the simulated field lab experimentation in the field.

  6. Reaction of niobium with hexane and methanol by mechanical grinding

    International Nuclear Information System (INIS)

    In mechanical alloying (MA) processing, alcohol, acetone and other organic solvents are often added as dispersants in order that powders will not stick to a vessel. It has been however considered that these organic solvents are simply additives. Enough attention has not been paid to the role or reaction of these dispersants. Recently, it was found that these organic solvents could react with some metals. For example, the authors reported that NbC is obtained by a reaction between Nb and methanol in the preparation of Al3Nb intermetallics by the MA method. Niobium hydrides are obtained by milling of Nb powders in hydrocarbon. In this paper, the authors discuss the reaction between Nb powder and hexane (C6H14) or methanol (CH3OH) during mechanical grinding (MG) processing

  7. Analysis of Temperature Field and Thermal Crown of Roll During Hot Rolling by Simplified FEM

    Institute of Scientific and Technical Information of China (English)

    GUO Zhong-feng; LI Chang-sheng; XU Jian-zhong; LIU Xiang-hua; WANG Guo-dong

    2006-01-01

    Thermal crown of roll is an important factor, which affects strip profile. It is necessary to analyze the temperature field and thermal crown of roll for hot strip mill. A new simplified finite element method (FEM) was used to analyze the temperature field and thermal crown of roll, and corresponding models were built according to the practical boundary conditions. Transient roll temperature field and thermal crown were simulated by ANSYS FEM software with considering transient thermal contact and complex boundary condition. Temperature and thermal crown variations on roll surface nodes were obtained. The thermal crown results of roll obtained by FEM simulation were in good agreement with the measured data, indicating that simplified FEM models and results were correct.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  10. SASS Applied to Optimum Work Roll Profile Selection in the Hot Rolling of Wide Steel

    Science.gov (United States)

    Nolle, Lars

    The quality of steel strip produced in a wide strip rolling mill depends heavily on the careful selection of initial ground work roll profiles for each of the mill stands in the finishing train. In the past, these profiles were determined by human experts, based on their knowledge and experience. In previous work, the profiles were successfully optimised using a self-organising migration algorithm (SOMA). In this research, SASS, a novel heuristic optimisation algorithm that has only one control parameter, has been used to find the optimum profiles for a simulated rolling mill. The resulting strip quality produced using the profiles found by SASS is compared with results from previous work and the quality produced using the original profile specifications. The best set of profiles found by SASS clearly outperformed the original set and performed equally well as SOMA without the need of finding a suitable set of control parameters.

  11. Separation of P Phase and Fe Phase in High Phosphorus Oolitic Iron Ore by Ultrafine Grinding and Gaseous Reduction in a Rotary Furnace

    Science.gov (United States)

    Gao, Jintao; Guo, Lei; Guo, Zhancheng

    2015-10-01

    Due to the oolitic structure of the high phosphorus iron ore and the closely wrapping of apatite and hematite phases, an approach using jet mill was utilized to grind the ore to ultrafine 0.01 to 0.001 mm, which realizes the dissociation of apatite phase and hematite phase. Then in a laboratory scale rotary furnace, high phosphorus ores of different sizes were reduced by reducing gas at sub-melting point temperatures (973 to 1173 K [700 to 900 °C]). In the rotating inclined reactor, the ore particles reacted with the reducing gas coming from the opposite direction in a rolling and discrete state, which greatly improved the kinetic conditions. In this study, the reaction rate increases significantly with the decrease of particle size. For the ultrafine high phosphorus iron ores, the metallization ratio can reach 83.91 to 97.32 pct, but only 33.24 to 40.22 pct for powders with the size of 0.13 to 0.15 mm. The reduced particles maintained their original sizes, without the presence of sintering phenomenon or iron whisker. Hence, two kinds of products were easily obtained by magnetic separation: the iron product with 91.42 wt pct of Fe and 0.19 wt pct of P, and the gangue product with 13.77 wt pct of Fe and 2.32 wt pct of P.

  12. Progress in abrasive and grinding technology

    CERN Document Server

    Xu, Xipeng

    2009-01-01

    The grinding and abrasive processing of materials are machining techniques which use bonded or loose abrasives to remove material from workpieces. Due to the well-known advantages of grinding and abrasive processes, advances in abrasive and grinding technology are always of great import in enhancing both productivity and component quality. In order to highlight the recent progress made in this field, the editor invited 21 world-wide contributions with the aim of gathering together all of the achievements of leading researchers into a single publication. The authors of the 21 invited papers, of

  13. Chatter in a transverse grinding process

    Science.gov (United States)

    Yan, Yao; Xu, Jian; Wiercigroch, Marian

    2014-02-01

    In transverse grinding, the wheel moves along the workpiece, which induces unique grinding dynamics. To understand these dynamic phenomena, specifically the grinding chatter, a new dynamical model of the process is proposed, in which the wheel position is assumed to be quasi-static since the transverse wheel velocity is small. From the stability and bifurcation analyses of the chatter vibration, it appears that the dynamics of the process is governed by the quasi-static interactions. Moreover, the obtained results also show that the wheel and workpiece chatters are quite different, having continuous and intermittent characters respectively.

  14. The Inlet Engine Valves Grinding Using Different Types of Cutting Fluids and Grinding Wheels

    Directory of Open Access Journals (Sweden)

    Eraldo Jannone da Silva

    2002-06-01

    Full Text Available In this paper an experimental research is presented in which different types of cutting fluids (a cutting oil and three different types of soluble oils and grinding wheels (alumina and vitrified CBN were tested in the inlet engine valves grinding. As evaluation parameters the workpiece residual stress and the grinding wheel wear were analyzed. The cutting fluid and the grinding wheel types adopted resulted in changes in all the parameters, due to the different lubricant abilities among the fluids and due to the differences in the mechanical and thermal properties among the abrasives tested. For grinding this steel, the CBN wheel is the best choice, mainly due to compressive residual stress results obtained for all cutting fluids tested. The cutting oil is the most adequate cutting fluid to be used, due to its higher lubricity and ability in keeping the wheel sharp for longer periods of time, reducing the overall grinding energy and the thermal damage.

  15. Shear-mode grinding force criteria of Zerodur and Pyrex

    Science.gov (United States)

    Hashimoto, Hiroshi; Imai, Kenichiro

    1995-08-01

    Experimental grinding of Zerodur and Pyrex demonstrated shear-mode grinding criteria (SM' GFC), which is a repeatable deterministic function of grinding conditions including materials and grinding wheels. Both criteria as with BK7 glass previously reported, are found to be the logarithmic function of removal rate.

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

    OpenAIRE

    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...

  17. NiO/Fe2O3湿式行星球磨中的噪声能消耗与效率%Noisy-power dissipation and efficiency in NiO/Fe2O3 wet grinding by planetary ball mill

    Institute of Scientific and Technical Information of China (English)

    姚云; 谢刚; 侯彦青; 李荣兴; 罗伟红; 彭如振; 于站良

    2014-01-01

    The relationship between the efficiency of NiO/Fe2O3 wet grinding and noisy-power dissipation was studied. The optimal grinding parameters were found as:a slurry water content of 64.10%-85.47%, ball number ratio of 360/20, revolution speed of 300.9 r/min, powder-filling ratio of 10.88%, ball-filling ratio of 20.53%-23.88%, and grinding time of approximately 6 h. The discrete element method (DEM) was employed to analyze relationship between the noisy-power dissipation and the grinding efficiency, and equations describing the relationship were derived. The mean particle size of the ground powder decreased with a decrease in the degree of noisy-power dissipation, while the grinding efficiency and the amount of specific impact power used decreased with an increase in the degree of noisy-power dissipation.%研究NiO/Fe2O3湿式混合与球磨过程中的噪声能消耗、球磨效率及二者之间的关系。结果表明,球磨工艺的最佳工艺参数为:填水率64.10%~85.47%,小/大球个数比360/20,球磨机转速300.9 r/min,填粉率约10.88%,填球率20.53%~23.88%,球磨时间6 h。引入离散元法(DEM)分析球磨过程中噪声能消耗与球磨效率之间的关系,得到噪声能消耗与填球率关系的经验方程。研究表明粉体的平均粒度随着噪声能的消耗而减小,而球磨效率和球碰撞能的利用率则随着噪声能消耗的增加而减小。

  18. Analysis of the cutting fluid influence on the deep grinding process with a CBN grinding wheel

    Directory of Open Access Journals (Sweden)

    Ronaldo Yoshinobu Fusse

    2004-09-01

    Full Text Available The application of cutting fluid in a deep grinding process is becoming more and more important, mainly where the cutting fluids are used as an "external" agent to the grinding conditions. The role of the fluid in grinding operations is in refrigeration of the workpiece, removal of the shavings, lubrication of the grinding zone, and refrigeration and cleaning of the wheel. The efficiency of a cutting fluid will depend mainly of the type of fluid that will be used. In this work, the influences of the type of cutting fluid used in a deep grinding process of the steel VC131 using CBN grinding wheel are analyzed. Three different types of cutting fluids were used: a vegetable emulsion, a synthetic solution and a integral oil. The variables analyzed during and after the grinding process were the grinding force, the superficial roughness, the acoustic emission (EA, the temperature of the piece and the G ratio (relationship between the volume of material removed from the piece and the volume worn off the grinding wheel. The integral oil showed the best performance relative to the following output variables: EA, cutting force and G ratio. The vegetal emulsion was the fluid that best dissipated heat from the cutting region.

  19. Multiparameter Optimization and Controlling for Cylindrical Grinding Process

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper bursts the bondage of conventional no-burn thought, presents an optimum strategy permitting burn appear in grinding roughing stage, but the burning layer can be summed on the following finishing stage. On the base of the basic grinding models, the objective function and constrained functions for the multiparameter optimum grinding models had been built in this paper. By the computer simulation, the nonlinear optimum grinding control parameters had been obtained, and the truth grinding process had...

  20. The grinding of uranium dioxide from fluidized beds

    International Nuclear Information System (INIS)

    This work deals with the UO2 vibratory grinding, the UO2 obtained from fluidized beds. In this study the grinding time has been correlated with surface area, stoichiometry, granulometry and grinded product contamination. The efficiency losses in the grinding of moisten UO2 are outlined. Finally it is made a brief study of the granulate obtained from the grinded UO2 as well as the green pellets resulting from it, taking into consideration the dispersion of its density and height. (Author)

  1. Development of centrifugal casting high speed steel rolls

    Institute of Scientific and Technical Information of China (English)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  3. Particle size distribution and suspension stability in aqueous submicron grinding of CaCO3 and TiO2

    OpenAIRE

    Ohenoja, K. (Katja)

    2014-01-01

    Abstract During the past decade submicron and nanoparticles have aroused a wide interest and gained new applications due to their high surface area and strength. Grinding with a wet stirred media mill is usually the last process step before the submicron or nanoparticles are added to an application, and the step where the final particle size distribution is achieved. Since stirred media milling is an energy-intensive process, energy efficiency should be optimized. This can be done by dete...

  4. High coercivity induced by mechanical milling in cobalt ferrite powders

    OpenAIRE

    Ponce, A. S.; E. F. Chagas; Prado, R. J.; Fernandes, C. H. M.; Terezo, A. J.; Baggio-Saitovitch, E.

    2013-01-01

    In this work we report a study of the magnetic behavior of ferrimagnetic oxide CoFe2O4 treated by mechanical milling with different grinding balls. The cobalt ferrite nanoparticles were prepared using a simple hydrothermal method and annealed at 500oC. The non-milled sample presented coercivity of about 1.9 kOe, saturation magnetization of 69.5 emu/g, and a remanence ratio of 0.42. After milling, two samples attained coercivity of 4.2 and 4.1 kOe, and saturation magnetization of 67.0 and 71.4...

  5. NBCM with Flat Roll in the Finish Stand

    Institute of Scientific and Technical Information of China (English)

    Xiangwei KONG; Hezhou YE; Jianzhong XU; Guodong WANG; Xianghua LIU; Junwei ZHANG

    2004-01-01

    With the development of the market, it becomes a demanding task for producers to make flexible production schedules to shorten production cycle. Schedule-free rolling is needed. If the CVC work roll of the F6 and F7 stands in certain 2050 mm hot rolled strip mill are substituted by flat roll (aim to SFR) and the strip profile is controlled by the existing bending force, the control ability is not adequate. This fact has been tested through on-line experiment and has been given in this article. The NBCM (new backup roll crowning method) is recommended to improve the profile control ability. Finally the plastic deformation of the strip and the elastic deformation of the roll are analyzed by employing coupled calculation of rigid-plastic finite element method and G-function method, and the optimal range of the crown of backup roll is given theoretically.

  6. Effect of Controlled Cooling After Hot Rolling on Mechanical Properties of Hot Rolled TRIP Steel

    Institute of Scientific and Technical Information of China (English)

    WU Di; LI Zhuang; L(U) Hui-sheng

    2008-01-01

    A three-step cooling pattern on the runout table (ROT) was conducted for the hot rolled TRIP steel. Microstructural evolution during thermomechanical controlled processing (TMCP) was investigated. Proeessing condition of controlled cooling on a ROT in the laboratory rolling mill was discussed. The results indicated that the microstructure containing polygonal ferrite, granular bainite and a significant amount of the stable retained austenite can be obtained through three-step cooling on the ROT after hot rolling. TMCP led to ferrite grain refinement. Controlled cooling after hot rolling resulted in the stability of the remaining austenite and a satisfactory TRIP effect. Excellent mechanical properties were obtained through TMCP for the hot rolled TRIP steel.

  7. ONLINE GRINDING WHEEL WEAR COMPENSATION BY IMAGE BASED MEASURING TECHNIQUES

    Institute of Scientific and Technical Information of China (English)

    WAN Daping; HU Dejin; WU Qi; ZHANG Yonghong

    2006-01-01

    Automatic compensation of grinding wheel wear in dry grinding is accomplished by an image based online measurement method. A kind of PC-based charge-coupled device image recognition system is schemed out, which detects the topography changes of the grinding wheel surface. Profile data, which corresponds to the wear and the topography, is measured by using a digital image processing method. The grinding wheel wear is evaluated by analyzing the position deviation of the grinding wheel edge. The online wear compensation is achieved according to the measure results. The precise detection and automatic compensation system is integrated into an open structure CNC curve grinding machine. A practical application is carried out to fulfil the precision curve grinding. The experimental results confirm the benefits of the proposed techniques, and the online detection accuracy is less than 5 μm. The grinding machine provides higher precision according to the in-process grinding wheel error compensation.

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

    OpenAIRE

    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 ...

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

    Institute of Scientific and Technical Information of China (English)

    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.

  10. 冷轧机附加倾斜后双侧非对称轧制力的计算%Asymmetric Roll Force Calculation With Additional Tilt for Drive Side and Operator Side of Cold Strip Mill

    Institute of Scientific and Technical Information of China (English)

    刘宝权; 张鸿; 王自东; 王军生; 张岩

    2011-01-01

    对冷轧带钢轧制过程中因辊缝倾斜调整过量所导致的单边浪缺陷和断带进行了分析,应用影响函数法计算辊系变形,通过迭代计算出附加倾斜后的传动侧轧制力、操作侧轧制力、辊间压力分布、单位宽度轧制力分布、出口厚度横向分布、出口横向张应力分布。理论计算和实际测量结果表明,冷轧机双侧轧制力差值与倾斜调整量呈近似线性增长的规律。根据轧制力差值与倾斜量之间的比例关系,用实测轧制力差值对倾斜值进行动态限幅,可有效避免冷轧过程中断带事故的发生。%The single edge wave and strip break caused by excessive tilting adjustment were analyzed. Influence func tion method was adopted to model the roll deformation. Adding different tilt, roll force of drive side, roll force of operator side, transverse distribution of contact pressure between rolls, transverse distribution of roll force, trans verse distribution of strip thickness at exit side and transverse distribution of tension at exit side were calculated by using iterative method. The theoretical calculation and the actual measurement results show that the difference be- tween the bilateral increases almost linearly with tilt adjustment value. The break strip accidents are effectively aver ted by dynamic limiting to tilt setting value with the measured differential roll force, according to the proportional relationship between the differential roll force and the tilt.

  11. 冷轧机工作辊非对称弯辊的板形调控理论研究与应用%Theoretical research and application of the asymmetrical bending of work rolls for shape control in a cold rolling mill

    Institute of Scientific and Technical Information of China (English)

    刘宝权; 张鸿; 王自东; 王军生; 张岩

    2012-01-01

    为减少冷轧带钢的非对称板形缺陷的产生,设计了工作辊非对称弯辊控制系统.应用影响函数法计算辊系变形,同时考虑辊缝中金属横向流动对带钢出口横向张力分布的影响,通过迭代法计算出工作辊两端施加不同弯辊力后的辊间压力分布、出口厚度横向分布以及出口横向张应力分布.理论分析结果表明,工作辊非对称弯辊可以在一定程度上改善辊间压力分布不均,减轻轧辊磨损和减少轧辊掉皮事故的发生,降低带钢边部的非对称板形缺陷.实际应用结果证明,当倾斜调整量小于10%时,应用工作辊非对称弯辊替代倾斜调整,可以获得更好的板形精度.%An asymmetrical bending control system of work rolls was designed to decrease the asymmetrical flatness defect of a cold-rolled strip.The influence function was adopted to calculate the deformation of the roll system and the effect of the lateral flow of metal in the roll gap on the transverse tension distribution of the strip at the exit side was taken into account.When different bending forces were exerted on both ends of work rolls,the contact pressure distribution between rolls,the lateral thickness distribution and the tension stress distribution of the strip at the exit side were calculated through the iterative method.The results of theoretical analysis show that the asymmetrical bending of work rolls can improve the pressure distribution between rolls,reduce the wear and the peeling off of rolls,and decrease the asymmetrical flatness defect of the strip at the edge.The application results prove that when the actual tilt is less than 10%,a higher accuracy of flatness is obtained with asymmetrical bending than work roll tilting.

  12. Surface integrity of GH4169 affected by cantilever finish grinding and the application in aero-engine blades

    Institute of Scientific and Technical Information of China (English)

    Li Xun; Ma Shuang; Meng Fanjun

    2015-01-01

    GH4169 is the main material for aero-engine blades and integrated blisks. Because GH4169 has a poor milling performance, the profile precision and surface integrity of blades and integrated blisks are difficult to be met by utilizing the conventional milling process, which directly influence the global performance and reliability of aero-engines. Through grinding experiments on parameters and surface integrity optimization, the helical cantilever grinding process utilizing a 300# CBN RB wheel is presented and applied in finish machining of GH4169 blades. The profile errors of the blade surface are within ±0.01 mm, the roughness is less than 0.4 lm, the residual compressive stresses and the hardening rate are appropriate, there are no phenomena of burr and smearing with the grinding chips, and the leading/trailing edge can be smoothly connected with the suction/pressure surface. All the experimental results indicate that this grinding process is greatly suitable for the profile finish machining of GH4169 blades.

  13. Surface integrity of GH4169 affected by cantilever finish grinding and the application in aero-engine blades

    Directory of Open Access Journals (Sweden)

    Li Xun

    2015-10-01

    Full Text Available GH4169 is the main material for aero-engine blades and integrated blisks. Because GH4169 has a poor milling performance, the profile precision and surface integrity of blades and integrated blisks are difficult to be met by utilizing the conventional milling process, which directly influence the global performance and reliability of aero-engines. Through grinding experiments on parameters and surface integrity optimization, the helical cantilever grinding process utilizing a 300# CBN RB wheel is presented and applied in finish machining of GH4169 blades. The profile errors of the blade surface are within ±0.01 mm, the roughness is less than 0.4 μm, the residual compressive stresses and the hardening rate are appropriate, there are no phenomena of burr and smearing with the grinding chips, and the leading/trailing edge can be smoothly connected with the suction/pressure surface. All the experimental results indicate that this grinding process is greatly suitable for the profile finish machining of GH4169 blades.

  14. Comparative analysis of milling results on the tail-end reduction passages of the wheat flour milling process: Conventional vs. eight-roller milling system

    Directory of Open Access Journals (Sweden)

    Fišteš Aleksandar Z.

    2015-01-01

    Full Text Available Introduction of the eight-roller mill into the wheat flour milling process significantly reduces the investment costs and overall energy requirements compared to the conventional milling system. However, the conditions for controlled milling are less favorable and could result in deterioration of flour yield and quality. Paper compares milling results obtained using a conventional process and process with an eight-roller mill employed on the tail-end passages of the reduction system. At the same roll gap and under the same sieving conditions, the flour release was lower in the process with the eight-roller mill compared to the conventional milling system. By decreasing the roll gap and increasing the upper size limit (granulation of flour in the process with the eight-roller mill it is possible to increase flour yield and decrease milling energy consumption per unit mass of flour produced. This can be achieved without deterioration of flour quality as determined by ash content. [Projekat Ministarstva nauke Republike Srbije, br. 031014

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

    DEFF Research Database (Denmark)

    Lagergren, J.; Wanheim, Tarras; Precz, W.;

    2006-01-01

    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 recordings were...

  16. High-speed milling of light metals

    Directory of Open Access Journals (Sweden)

    F. Cus

    2007-09-01

    Full Text Available Purpose: of this paper: Introduction applicability of high-speed cutting of light metals is presented in this paper.Design/methodology/approach: HSC is the result of numerous technical advances ensuring that milling has become faster than conventional milling and has gained importance as a cutting process. The advantages of the HSC milling are higher productivity owing to the reduction of machining times increase of the flow time of production, reduction of the number of technological operations, increase of the surface quality and longer service life of tools. The machining conditions for execution of the HSC (36000min-1 and feeding 20m/min require modernly built machine tools to meet those machining conditions.Findings: Continuous development of new materials is more and more dynamical, particularly, in the automobile, aircraft and electronic industry and in the manufacture of various mechanical parts. Also the achievements in the area of building of machines and tools, ensuring high cutting speeds (highly efficient machining have contributed to development of the process.Research limitations/implications: High quality of the surfaces, the quality of this so-called HSC milling can be compared to grinding.Practical implications: High-speed milling of light metals from aluminium and magnesium is more and more frequently used in practice. This result is high quality of the surface and shorter machining times. In some cases when machining by grinding is specified, the latter is omitted.Originality/value: The applicability of high-speed milling has proved to be successful, when aluminum and magnesium alloying materials are machined.

  17. Tandem strip mill's multi-parameter coupling dynamic modeling based on the thickness control

    Science.gov (United States)

    Peng, Yan; Zhang, Yang; Sun, Jianliang; Zang, Yong

    2015-03-01

    The rolling process is determined by the interaction of a number of different movements, during which the relative movement occurs between the vibrating roll system and the rolled piece, and the roll system's vibration interacts with the strip's deformation and rigid movement. So many parameters being involved leads to a complex mechanism of this coupling effect. Through testing and analyzing the vibration signals of the mill in the rolling process, the rolling mill's coupled model is established with comprehensive consideration of the coupling interaction between the mill's vertical vibration, its torsional vibration and the working roll's horizontal vibration, and vibration characteristics of different forms of rolling mill's vibration are analyzed under the coupling effect. With comprehensive attention to the relationship between the roll system, the moving strip and the rolling parameters' dynamic properties, and also from the strip thickness control point of view, further research is done on the coupling mechanism between the roll system's movement and the moving strip's characteristics in the rolling process. As a result, the law of inertial coupling and the stiffness coupling effect caused by different forms of the roll system's vibration is determined and the existence of nonlinear characteristics caused by the elastic deformation of moving strip is also found. Furthermore, a multi-parameter coupling-dynamic model is established which takes the tandem strip mill as its research object by making a detailed kinematics analysis of the roll system and using the principle of virtual work. The coupling-dynamic model proposes the instruction to describe the roll system's movement, and analyzes its dynamic response and working stability, and provides a theoretical basis for the realization of the strip thickness' dynamic control.

  18. Generation of wear during the production of drug nanosuspensions by wet media milling.

    Science.gov (United States)

    Juhnke, Michael; Märtin, Dirk; John, Edgar

    2012-05-01

    Wet media milling is an established technique for the commercialized top-down production of nanoparticulate drug suspensions. These drug nanosuspensions can be transferred into the related drug products, like capsules, tablets and injectables. The generation of wear during stirred media milling of a drug compound was investigated for grinding media made from yttrium stabilized zirconia. Drug compound and drug nanosuspension were characterized initially by their mechanical and rheological properties. The generation of wear from grinding media has been investigated simultaneously with the reduction of drug particle size by evaluating several grinding media supplier and diameter as well as process parameters stirrer tip speed and specific energy input. Grinding media quality and process parameters were identified with strong impact on the amount of generated wear and on drug particle size distribution. Wear from grinding media characterized by elemental zirconium and yttrium could be significantly minimized by operating with the favored grinding media quality and with optimal stirrer tip speed and specific energy input. Wear debris, respectively wear particles from grinding media, were identified with respect to morphology and particle size. Finally, the overall contamination by raw materials and by wear during processing characterized by elemental iron, silicium, yttrium and zirconium as well as the mean size of contamination particles are presented for selected drug nanosuspensions. PMID:22269938

  19. Analysis on the grinding quality of palm oil fibers by using combined grinding equipment

    Science.gov (United States)

    Gan, H. L.; Gan, L. M.; Law, H. C.

    2015-12-01

    As known, Malaysia is the second largest palm oil producer worldwide after Indonesia, therefore indicating the abundance of its wastes within the country. The plantation would be seen to increase to at least 5.2 million ha by 2020, and the waste generation would be 50-70 times the plantation. However, the efficiency of bulk density is reduced. This is one of the main reasons of the initiation of this size reduction/ grinding research. With appropriate parameters, grinding will be seen to be helping in enhancing the inter-particle bindings, subsequently increasing the quality of final products. This paper focuses on the grinding quality involving palm oil wastes by using the Scanning Electron Microscope (SEM). The samples would first be ground to powder at varying grinding speed and finally got the randomly chosen particles measured to obtain the size range. The grinding speed was manipulated from 15 Hz to 40 Hz. From the data obtained, it was found the particles fineness increased with increasing grinding speed. In general, the size ranged from 45 μm to about 600 μm, where the finest was recorded at the speed of 40 Hz. It was also found that the binding was not so encouraging at very low speeds. Therefore, the optimum grinding speed for oil palm residues lied in the range of 25 Hz to 30 Hz. However, there were still limitations to be overcome if the accuracy of the image clarity is to be enhanced.

  20. Energy requirement for fine grinding of torrefied wood

    Energy Technology Data Exchange (ETDEWEB)

    Repellin, Vincent; Govin, Alexandre; Guyonnet, Rene [Department of Powder and Multi-Components Materials (PMMC), SPIN Research Center, Ecole des Mines de Saint Etienne (EMSE), 158 Cours Fauriel, F-42023 Saint-Etienne (France); Rolland, Matthieu [Process Developments and Engineering Division, Chemical Engineering Department, Institut Francais du Petrole (IFP-Lyon), F-69390 Vernaison (France)

    2010-07-15

    The purpose of this study is to investigate the influence of torrefaction on wood grinding energy. Wood chips were torrefied at different temperatures and durations. The energy required to obtain fine powder was measured. Particle size analyses were carried out on each powder sample. It is showed that torrefaction decreases both grinding energy and particle size distribution. A criterion to compare grindability of natural and torrefied wood is proposed. It takes into account both grinding energy and particle size distribution. It accounts the energy required for grinding particles to sizes inferior to 200 {mu}m, for given grinding conditions. Torrefaction is characterised by the anhydrous weight loss (AWL) of wood. For AWL inferior to around 8%, grinding energy decreases fast. Over 8%, grinding energy decreases at a slow rate. Particle size distribution decreases linearly as the AWL increases. Both for spruce and beech, the grinding criterion is decreased of 93% when the AWL is around 28%. (author)

  1. Temperature Control of Hot Strip Finishing Mill with Inter Stand Cooling

    Science.gov (United States)

    Sekiguchi, Kunio; Anbe, Yoshiharu; Imanari, Hiroyuki

    It is important for hot strip mill to keep finishing mill delivery temperature to it’s target value because of yield strength and tensile strength of rolled strip. We propose a new method for finishing mill delivery temperature control (FDTC) of a hot strip mill using inter stand strip coolant (ISC). FDTC consists of initial setting (before threading) values calculation of ISC flow rate and finishing mill speed, feed forward FDTC (FF-FDTC) and feedback FDTC (FB-FDTC). The mathematical strip temperature model of finishing mill was identified using normal operating data and some tests. Actual mill application with 7 stands finishing mill showed good FDTC results and also it made possible to increase rolling speed which increase production rate.

  2. Reasonable Ball Size of Ball Mill for Preparing Coal Water Fuel and Forecasting Productive Capacity

    Institute of Scientific and Technical Information of China (English)

    张荣曾; 刘炯天; 徐志强; 郑明

    2002-01-01

    By using the matrix theory, a 5-parameter grinding mathema tical model is established. Based on the properties of feed coal and requirement s for size distribution of final product, the model gives the required grinding probability for various particles and corresponding ball size distribution. By u sing this model, 3 different sizes of ball mill are designed and put into commer cial use for coal water fuel. The forecasted ball mill capacity, the particle si zes and particle size distribution as well as the coal water fuel quality parame ters are all in line with industrial operation results, which have proved the su itability of the model.

  3. Performance of Disk Mill Type Mechanical Grinder for Size Reducing Process of Robusta Roasted Beans

    Directory of Open Access Journals (Sweden)

    Sri Mulato

    2006-12-01

    Full Text Available One of improtant steps in secondary coffee processing that influence on final product quality such as consistency and uniformity is milling process. Usually, Indonesian smallholder used "lumpang" for milling coffee roasted beans to coffee powder product which caused the final product not uniformed and consistent, and low productivity. Milling process of coffee roasted beans can be done by disk mill type mechanical grinder which is used by smallholder for milling several cereals. Indonesian Coffee and Cocoa Research Institute have developed disk mill type grinding machine for milling coffee roasted beans. Objective of this research is to find performance of disk mill type grinding machine for size reducing process of Robusta roasted beans from several size dried beans and roasting level treatments. Robusta dried beans which are taken from dry processing method have 13—14% moisture content (wet basis, 680—685 kg/m3 density, and classified in 3 sizes level. The result showed that the disk mill type of grinding machine could be used for milling Robusta roasted beans. Machine hascapacity 31—54 kg/h on 5,310—5,610 rpm axle rotation and depend on roasting level. Other technical parameters were 91—98% process efficientcy, 19—31 ml/ kg fuel consumption, 0.3—1% slips, 50—55% particles had diameter less than 230 mesh and 38—44% particles had diameter bigger than 100 mesh, 32—38% lightness was increased, 0.6—12.6% density was decreased, and solubility of coffee powder between 28—30%. Cost milling process per kilogram of Robusta roasted beans which light roast on capacity 30 kg/hour was Rp362.9. Key words : Coffee roasted, Robusta, disk mill, mechanical grinder, size reduction.

  4. Soft Compensation for CNC Crankshaft Grinding Machine Tool

    OpenAIRE

    Yongjun Liu; Jinwei Fan; Wei Miao

    2013-01-01

    Wear and deformation CNC grinding machine tool, will be aggravated over time of which will influence the manufacturing precision. To reduce the effect, the soft compensation method by modifying NC instruction was put forward to maintain the manufacturing precision of CNC crankshaft grinding machine tool. The error sources were analyzed, the errors caused by grinding force were calculated, and the precise grinding kinematics model was deduced by the multibody kinematics. Numerical simulation a...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  6. Analysis of the thermal profile of work rolls in the hot strip rolling process

    Institute of Scientific and Technical Information of China (English)

    Xuanli Zhang; Jie Zhang; Xiaoyan Li; Haixia Li; Gangcheng Wei

    2004-01-01

    A 2-dimension axisymmetric model was developed by the finite-difference method, which can be used to predict the transient temperature field and thermal profile of work rolls in the hot strip rolling process. To demonstrate the accuracy and reliability of the solution developed, the calculation results were compared with the production data of a 1700 mm hot strip rolling mill and good agreement was found between them. The effect of strip width and roll shifting on the thermal expansion of the work rolls was studied.It is found that the strip width has marked effect on the efficient thermal crown. Initially, when the rolling strip changes from narrow to wide, a bigger efficient thermal crown can be quickly achieved; afterwards, when the rolling strip changes from wide to narrow,not only the influence of uneven wear can be reduced but also the excessive efficient thermal crown can be avoided. It is also found that the work roll shifting has a determinate but not obvious effect on the reduction of the efficient thermal crown, and will make the strip shape unstable without being used properly.

  7. Practice of Improving Roll Deformation Theory in Strip Rolling Process Based on Boundary Integral Equation Method

    Science.gov (United States)

    Yuan, Zhengwen; Xiao, Hong; Xie, Hongbiao

    2014-02-01

    Precise strip-shape control theory is significant to improve rolled strip quality, and roll flattening theory is a primary part of the strip-shape theory. To improve the accuracy of roll flattening calculation based on semi-infinite body model, a new and more accurate roll flattening model is proposed in this paper, which is derived based on boundary integral equation method. The displacement fields of the finite length semi-infinite body on left and right sides are simulated by using finite element method (FEM) and displacement decay functions on left and right sides are established. Based on the new roll flattening model, a new 4Hi mill deformation model is established and verified by FEM. The new model is compared with Foppl formula and semi-infinite body model in different strip width, roll shifting value and bending force. The results show that the pressure and flattening between rolls calculated by the new model are more precise than other two models, especially near the two roll barrel edges.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  9. Mechanics of Thin Strip Steering in Hot Rolling

    Science.gov (United States)

    Jiang, Zhengyi; Tieu, Kiet A.

    2004-06-01

    The hot rolling of thin strip can result in several problems in hot rolling, for instance, the control of strip steering, strip shape and flatness and surface roughness etc. Therefore, the hot rolling of thin strip brings out a requirement of innovative technologies such as the extended control of shape and flatness, steering control and reduction of load by roll gap lubrication. In this paper, the authors focus on the analysis of thin strip snaking movement, as well as solve the related problems such as the shape and flatness due to a larger reduction applied when the strip is thinner. A finite element method was used to simulate this nonsymmetricity rolling considering the non-uniform reduction along the strip width. The calculated spread is compared with the measured values obtained from the rolling mill in laboratory and the friction effect is also discussed.

  10. 30 CFR 75.1723 - Stationary grinding machines; protective devices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stationary grinding machines; protective devices. 75.1723 Section 75.1723 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF....1723 Stationary grinding machines; protective devices. (a) Stationary grinding machines other...

  11. 30 CFR 77.401 - Stationary grinding machines; protective devices.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stationary grinding machines; protective... OF UNDERGROUND COAL MINES Safeguards for Mechanical Equipment § 77.401 Stationary grinding machines; protective devices. (a) Stationary grinding machines other than special bit grinders shall be equipped...

  12. 30 CFR 57.14115 - Stationary grinding machines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stationary grinding machines. 57.14115 Section... and Equipment Safety Devices and Maintenance Requirements § 57.14115 Stationary grinding machines. Stationary grinding machines, other than special bit grinders, shall be equipped with— (a) Peripheral...

  13. A Review of Literature on analysis of JIG Grinding Process

    DEFF Research Database (Denmark)

    Sudheesh, P. K.; Puthumana, Govindan

    2016-01-01

    Jig grinding is a process practically used by tool and die makers in the creation of jigs or mating holes and pegs on dies.The abrasives normally used in jig grinding are divided into Natural Abrasives and Artificial Abrasives. Artificial Abrasiveare preferred in manufacturing of grinding wheels ...

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

    International Nuclear Information System (INIS)

    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)

  15. An FE Based On-line Model for the Prediction of Work Roll Thermal Profile in Hot Strip Rolling

    Science.gov (United States)

    Choi, Ji Won; Lee, Jung Hyeung; Sun, Cheng Gang; Hwang, Sang Moo

    2010-06-01

    Prediction and control of the thermal deformation of the work roll is vital for enhancing product quality in hot strip and plate rolling. In this paper, we present an on-line model for the prediction of the work roll thermal profile. The model is developed on the basis of an integrated finite element model for the coupled analysis of heat transfer and deformation occurring at the bite zone, to rigorously take into account the effect of various rolling parameters on the thermal behavior of the work roll. The validity of the model is demonstrated through comparison with measurements made in an industrial hot strip mill. Also, an emphasis is given to the examination the effect of some selected rolling parameters in an actual production environment.

  16. Effect of Load Distribution on Strip Crown in Hot Strip Rolling

    Institute of Scientific and Technical Information of China (English)

    Hongshuang DI; Jianzhong XU; Dianyao GONG; Xianghua LIU; Guodong WANG; Xiaoming HE; Liying BA

    2004-01-01

    In order to establish precision model, a software to calculate the strip crown of four-high hot rolling mill was developed by using affecting function method according to the strip crown calculation theory. The effect of work roll diameter, unit width rolling load, roll bending force, work roll crown, initial strip crown and reduction, etc, on load distribution effect rate was simulated by using the software. The results show that the load distribution effect rate increases with the increase of strip width, work roll diameter, unit width rolling load, roll bending force, work roll crown, initial strip crown and reduction. Based on the simulation results, base value of load distribution effect rate and fitting coefficients of six power polynomial of load distribution effect rate modification coefficient were determined considering all of the above parameters. A simplified mathematical model for calculating load distribution effect rate was established.

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

    International Nuclear Information System (INIS)

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Method of accurate grinding for single enveloping TI worm

    Institute of Scientific and Technical Information of China (English)

    SUN Yuehai; ZHENG Huijiang; BI Qingzhen; WANG Shuren

    2005-01-01

    TI worm drive consists of involute helical gear and its enveloping Hourglass worm. Accurate grinding for TI worm is the key manufacture technology for TI worm gearing being popularized and applied. According to the theory of gear mesh, the equations of tooth surface of worm drive are gained, and the equation of the axial section profile of grinding wheel that can accurately grind TI worm is extracted. Simultaneously,the relation of position and motion between TI worm and grinding wheel are expounded.The method for precisely grinding single enveloping TI worm is obtained.

  20. CHARACTERIZATION OF THE FRICTION CONDITIONS IN THE FINISHING STANDS OF A HOT STRIP MILL

    Directory of Open Access Journals (Sweden)

    Antonio Augusto Gorni

    2012-06-01

    Full Text Available The decrease in hot strength or even rolling load as strain increases in some stands of the finishing hot strip mill with no metallurgical reasons is a relatively common event. Apparently this fact is associated with modification in the tribological conditions between rolling stock and work roll surfaces due to unexpected interactions with scale. The aim of this work is to determine the values of the friction coefficient in the several stands of the finishing hot strip mill at Usiminas-Cubatão, as well to determine quantitative relationships between this coefficient and relevant process parameters, like strain degree and peripherical work roll speed.

  1. Cross Shear Roll Bonding

    DEFF Research Database (Denmark)

    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....

  2. Grinding Characteristic of Multi-walled Carbon Nanotubes-alumina Composite Particle

    Institute of Scientific and Technical Information of China (English)

    B MUNKHBAYAR; Nasan BAYARAA; Hafizur REHMAN; Junhyo KIM; Hanshik CHUNG; Hyomin JEONG

    2012-01-01

    The synthesis of new materials containing multi-walled carbon nanotubes (MWCNTs) and the microstructure of alumina particles were investigated and characterized.The MWCNTs and alumina particles were ground under both the dry and wet conditions with various rotation speeds (200-400 r/min) in planetary ball milling machine,and their combination characteristics were described.The experimental results were examined by scanning electron microscopy (SEM),X-ray diff action (XRD),transmission electron microscopy (TEM) and particle sizing analysis (PSA).SEM result revealed that the combination of MWCNTs -Alumina particles mixed quite well under both the dry and wet grinding with rotation speed of 400 r/min.XRD characterization indicated the better result could get in ground samples at a rotation speed of 400 r/min.PSA result showed the particle size decreased with increase the grinding speeds.From the overall results,we observed that the grinding method can be used to synthesize new material with high efficiency.

  3. Investigations on Fine Grinding of Mullite Ⅰ.The Effects of Processing Parameters on Size and Distributions of Mullite Powders in Attrtor

    Institute of Scientific and Technical Information of China (English)

    XINGCheng; LINan

    1994-01-01

    The effects of several processing parame-ters on size and distributions of mullite powders were studied in wet grinding with an attrition mill.The results show that there is an optimum initial slurry density,and also it has little rela-tionship with the media charge ratio.The size distributions of processed mullite are dependent on the grinding time and indepentdent of initial pulp density,Under given conditions,the larger the media charge ration is ,the finer the ground particle size will be.

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

    OpenAIRE

    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...

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

    International Nuclear Information System (INIS)

    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)

  6. Research on CNC Turning System of Aspheric Machining Grinding Wheel

    Institute of Scientific and Technical Information of China (English)

    ZOU Qin; GUO Yin-biao

    2005-01-01

    The technology of machining aspheric surface with high precision is the premise for the application of aspheric surface. The grinding machining with error compensation is a commonly used method to machine aspheric surface, which will directly influence the quality of aspheric workpiece surface. Multifunctional CNC grinding wheel truing system is a four-axis CNC truing system which can be applied to grinding wheel truing. In this system,DSP-based multi-axes motion control card is adopted as the controller, and visual C++ is used as development tool.When the design of hardware and software is completed, the system can implement truing of various grinding wheel with high precision aspheric machining such as plane grinding wheel, arc grinding one, and sphere grinding one.

  7. STUDY ON A NEW TYPE OF THROWAWAY SOFT GRINDING WHEELS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In accordance with the difficult problems of belt cross vibrations and effects of belt tension on machine spindle precision in abrasive belt grinding, a new soft grinding wheel is put forward, which is provided with the advantages of belt grinding and can be installed directly on the grinding machine spindle substituting for common grinding wheels. The new soft grinding wheel does not need any ancillary facilities and dressing devices in grinding. With analyzing error of wheel and grinding experiment, the highefficiency grinding characteristics grinding hardbrittle materials has been obtained.

  8. Multi-stage FE simulation of hot ring rolling

    Science.gov (United States)

    Wang, C.; Geijselaers, H. J. M.; van den Boogaard, A. H.

    2013-05-01

    As a unique and important member of the metal forming family, ring rolling provides a cost effective process route to manufacture seamless rings. Applications of ring rolling cover a wide range of products in aerospace, automotive and civil engineering industries [1]. Above the recrystallization temperature of the material, hot ring rolling begins with the upsetting of the billet cut from raw stock. Next a punch pierces the hot upset billet to form a hole through the billet. This billet, referred to as preform, is then rolled by the ring rolling mill. For an accurate simulation of hot ring rolling, it is crucial to include the deformations, stresses and strains from the upsetting and piercing process as initial conditions for the rolling stage. In this work, multi-stage FE simulations of hot ring rolling process were performed by mapping the local deformation state of the workpiece from one step to the next one. The simulations of upsetting and piercing stages were carried out by 2D axisymmetric models using adaptive remeshing and element erosion. The workpiece for the ring rolling stage was subsequently obtained after performing a 2D to 3D mapping. The commercial FE package LS-DYNA was used for the study and user defined subroutines were implemented to complete the control algorithm. The simulation results were analyzed and also compared with those from the single-stage FE model of hot ring rolling.

  9. Study Friction Distribution during the Cold Rolling of Material by Matroll Software

    Science.gov (United States)

    Abdollahi, H.; Dehghani, K.

    2007-04-01

    Rolling process is one of the most important ways of metal forming. Since the results of this process are almost finished product, therefore controlling the parameters affecting this process is very important in order to have cold rolling products with high quality. Among the parameters knowing the coefficient of friction within the roll gap is known as the most significant one. That is because other rolling parameters such as rolling force, pressure in the roll gap, forward slip, surface quality of sheet, and the life of work rolls are directly influenced by friction. On the other hand, in rolling calculation due to lake of a true amount for coefficient of friction a supposed value is considered for it. In this study, a new software (Matroll), is introduced which can determine the coefficient of friction (COF) and plot the friction hills for an industrial mill. Besides, based on rolling equations, it offers about 30 rolling parameters as outputs. Having the rolling characteristics as inputs, the software is able to calculate the coefficient of friction. Many rolling passes were performed on real industrial aluminum mill. The coefficient of friction was obtained for all passes. The results are in good agreement with the findings of the other researchers.

  10. VCR and ASR technology for profile and flatness control in hot strip mills

    Institute of Scientific and Technical Information of China (English)

    CAO Jian-guo; WEI Gang-cheng; ZHANG Jie; CHEN Xian-lin; ZHOU Yi-zhong

    2008-01-01

    The roll contour pattern and variety of work and backup roils in service and its effect on profile and flatness control performance in 1 700 mm hot strip mill at Wuhan Iron and Steel (Group) Corporation were tested and analyzed by the developed finite element models of different typical roll contours configurations. A rather smooth local work roll contour near strip edges and an increase in rolled length can be obtained by application of long stroke work roll shifting system with conventional work roll contours that is incapable of the crown control. In comparison with the conventional backup and work roll contours configuration, the crown control range by the roll bending force enhances by 12.79% and the roll gap stiffness increases by 25.26% with the developed asymmetry self-compensating work rolls(ASR) and varying contact backup rolls(VCR). A better strip profile and flatness quality, an increase in coil numbers within the rolling campaign and a significant alleviated effect of severe work roll wear contours on performance of edge drop control are achieved by the application of ASR with crown control and wear control ability in downstream stand F5 and VCR in all stands of 1 700 mm hot strip mill.

  11. A new speed optimization algorithm with application in pickling and rolling line

    Directory of Open Access Journals (Sweden)

    Xiaoyan Zhu

    2016-04-01

    Full Text Available In order to reduce equipment wear and operator pressure, as well as to improve the production efficiency of combined continuous pickling line and tandem cold rolling mill units, four sections’ speeds should be automatically optimized to control the three loopers’ abundance, which include the entry loopers’ entry speed, pickling speed, trimming speed, and tandem cold rolling mill entry speed. According to the optimal speed principle, a new optimization algorithm was proposed based on objective function. In this work, Nelder–Mead simplex method is applied to find the optimal solution by minimizing the objective function. In addition, the calculation of four initial speeds is specified, especially the initial tandem cold rolling mill entry speed. The proposed speed optimization algorithm was successfully applied to a 1450 mm continuous pickling line and tandem cold rolling mill. The acceleration and deceleration are smooth and steady when welding, trimming, or roll changing takes place in practice, the three loopers’ abundance are controlled in suitable range. Results show that the continuous pickling line unit could provide the material in maximum capacity to ensure that the tandem cold rolling mill unit’s production is efficient, and the rolling yield is greatly improved due to the decrease in the number of stops.

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

    OpenAIRE

    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 ...

  13. Grinding of WC–Co hardmetals

    OpenAIRE

    Hegeman, J.B J W; De Hosson, J. Th. M.; de With, G.

    2001-01-01

    This paper concentrates on the morphology of the ground surface of cobalt tungsten carbide (WC) composite materials that belong to the category of so-called hardmetals. A deformed and detached surface layer was found on top of the specimens after surface grinding with a diamond wheel. In order to determine aspects of material removal, various routes were followed. Etching the surface layer revealed WC grains in the subsurface of the machined samples. Most of these grains were plastically defo...

  14. Dressing of diamond grinding wheels by abrasive water jet for freeform optical surface grinding

    Science.gov (United States)

    Wang, Wei; Yao, Peng; Li, Chengwu; Huang, Chuanzhen; Wang, Jun; Zhu, Hongtao; Liu, Zengwen

    2014-08-01

    During the ultra-precision grinding of a large aperture mirror made of RB-SiC, the grinding wheel becomes dull rapidly, which will lead to an increase of grinding force and a decrease of grinding ratio. In this paper, diamond grinding sticks were dressed with micro SiC abrasive water jet and water jet. Through single factorial experiments, the influence of jet pressure on the dressing performance was investigated. To analyze and evaluate the effect of dressing quantitatively, the 3D roughness and the wheel topography were measured and compared with laser scanning confocal microscope before and after dressing. The experimental results show that the abrasive grains are well protruded from binder and the distribution of the abrasive grains becomes uniform after dressing by abrasive water jet when the dressing parameters are properly selected. The dressing performance of abrasive water jet is much better than water jet. For dressing ultra-fine grit size wheels, the abrasive size of the jet should be smaller than the wheel grit size to achieve a better result. The jet pressure is an obvious influence factor of the surface topography.

  15. Theoretical Study on Non-transmission High Efficient Parallel Camber Grinding Machine

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Be directed against the development trend of modern CNC grinding machine towards high precision and high efficiency, some general weaknesses of existing camber grinding machine are analyzed in detail. In order to develop new type CNC camber grinding machine that can grind complex die, and genuinely achieved accurate feed and high efficient grinding, a new type camber grinding machine is put forward, called non-transmission virtual-shaft CNC camber grinding machine. Its feed system is a parallel mechanism ...

  16. Freeform grinding and polishing with PROSurf

    Science.gov (United States)

    Wolfs, Franciscus; Fess, Edward; DeFisher, Scott; Torres, Josh; Ross, James

    2015-10-01

    Recently, the desire to use freeform optics has been increasing, including shapes such as torics and anamorphic aspheres. Freeform optics can be used to expand capabilities of optical systems. They can compensate for limitations in rotationally symmetric optics. These same traits that give freeform optics the ability to improve optical systems also makes them more challenging to manufacture. This holds true for grinding, polishing, and metrology. As freeform optics become more prevalent in the industry, tolerances will become more stringent, requiring deterministic manufacturing processes. To generate freeforms, it is crucial to have control over all aspects of the process. Controlling the surface definition is important for achieving a better surface finish during processing. Metrology will be required to adjust tool paths at various stages in manufacturing. During grinding, metrology will be used to adjust tool positions relative to the nominal tool path to compensate for repeatable machine and tooling error. For polishing, metrology will be used to deterministically adjust dwell relative to the amount of the error in different surface locations, allowing for convergence towards the desired surface at a uniform rate. OptiPro has developed PROSurf, a CAM software package for creating freeform tool paths and applying metrology-based corrections. The software can be used for both grinding and polishing freeform optics. The software has flexibility to allow for different methods of modelling the surface: mathematical equations, solid models, and point clouds. The software is designed to make it easier to manufacture and polish complex freeform optics.

  17. NORMAL PRESSURE AND FRICTION STRESS MEASUREMENT IN ROLLING PROCESSES

    DEFF Research Database (Denmark)

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

    2005-01-01

    the output from the transducer, the friction stress and normal pressure in the contact zone can be determined. The new concept differs from existing pin designs by a lower disturbance of lubricant film and material flow and limited penetration of material between transducer and roll. Aluminum, cupper...... and steel strips with a width of 40 mm was rolled with reduction varying from 2.7% to 29%, in a pilot mill. For evaluating the transducer, the measured contact forces are compared with external measurements of roll separating forces and torque. The determined friction coefficients are compared with values...

  18. Recent developments in semiprocessed cold rolled magnetic lamination steel

    Science.gov (United States)

    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.

  19. Recrystallization model for hot-rolling of 5182 aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A recrystallization model for hot-rolling of 5182 aluminum alloy was presented by means of the fractional softening during double interval deformation. It is found that the recrystallization rate depends on strain rate more sensitively than deformation temperature, and the time for full recrystallization is very short as strain rate is greater than 1 s-1. Using the recrystallization—time—temperature curves, the desirable hot rolled microstructure can be obtained by controlling the rolling speed, temperature and cooling rate before cooling during the last pass in reversing mill.

  20. On the grinding kinetics of tungsten ores%钨矿石磨矿动力学研究

    Institute of Scientific and Technical Information of China (English)

    鄢发明; 艾光华; 吴彩斌; 李晓东; 石志中; 毛文明

    2015-01-01

    The mathematical model of product particle size distribution of grinding process is established and predicted, which will be to the benefit of guiding mill grinding. Batch grinding experiments on Shizhyuan tungsten ores in different grinding time in the laboratory were made to show that particles conform to first order grinding kinetics when the particle size was no more than 0.1 millimeter, however, the particles conformed to n order grinding kinetics when the particle size was more than 0.1 millimeter. There was a power function relationship between the parameter k of first order grinding kinetics and diameter d, which distributed in function of R=R0exp[-(0.014 42+9.538 65d1.761 28)t];at n order grinding kinetics, the parameter k and diameter d were consistent with power function relationship, and the parameter n and diameter d were consistent with logarithmic function relationship, which distributed in function of R=R0exp [-(-0.134 1+1.151 42d0.681 69)t0.718 18-0.386 56lnd]. Through the comparison with theoretical values which were calculated by grinding kinetics equations with the grinding actual results, actual values had high degree of coincidence with it. Therefore the study establishes a theoretical basis for controlling the grinding product particle sizes by adjusting the feed quantity of mill and sand return of grader.%建立和预测磨矿过程的产品粒度分布数学模型有助于指导选矿厂磨矿实践.文中在实验室条件下对柿竹园钨矿石进行不同磨矿时间的分批磨矿试验.结果表明,矿粒在0.1 mm及其以下粒级符合一阶磨矿动力学,在0.1 mm以上粒级符合n阶磨矿动力学.一阶磨矿动力学参数k与粒径d呈幂函数关系,其动力学方程为R=R0exp[-(0.01442+9.53865d1.76128)t];n阶磨矿动力学参数中,k与粒径d呈幂函数关系,n与粒径d呈对数函数关系,其动力学方程为R=R0exp[-(-0.1341+1.15142d0.68169)· t0.71818-0.38656lnd].利用建立的磨矿动力

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

    Science.gov (United States)

    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.

  2. Analysis of CVC roll contour and determination of roll crown

    Institute of Scientific and Technical Information of China (English)

    Guang Xu; Xianjun Liu; Jiarong Zhao; Junwei Xiong

    2007-01-01

    Mathematical analysis of continuous variable crown (CVC) roll contour used in CSP production line was conducted and the roll contour function of CVC roll was obtained. The validation with actual CVC roll contour shows that the calculation values of the roll contour function and the actual roll contour parameters given by equipment provider are the same, which proves that the roll contour function of CVC rolls given in this article is correct. The nonlinear relationship between the roll crown of CVC rolls and roll shift amounts was deduced. The concept of crown extremum was given.

  3. Wire Electrical Discharge Truing of Metal Bond Diamond Grinding Wheels

    Energy Technology Data Exchange (ETDEWEB)

    McSpadden, SB

    2002-01-24

    Cylindrical wire EDM profile truing of the metal bond diamond wheel for precision form grinding of ceramics is presented in this report. First a corrosion-resistant, precise spindle with the high-electrical current capability for wire EDM truing of grinding wheel was fabricated. An arc profile was adopted in order to determine form tolerances capabilities of this process. Results show the wire EDM process can generate {micro}m-scale precision form on the diamond wheel efficiently. The wheel, after truing, was used to grind silicon nitride. Grinding forces, surface finish of ground components, and wheel wear were measured. The EDM trued wheel showed a reduction in grinding force from that of the stick dressed wheel. Surface finishes between the two truing methods were similar. In the beginning of the grinding, significant wheel wear rate was identified. The subsequent wheel wear rate stabilized and became considerably lower.

  4. Prediction of temperature distribution in the hot rolling of slabs

    Science.gov (United States)

    Serajzadeh, S.; Karimi Taheri, A.; Mucciardi, F.

    2002-03-01

    In the process of continuous hot slab rolling, it is vital to know the temperature distribution within the slab along the length of the rolling mill because temperature is the dominant parameter controlling the kinetics of metallurgical transformations and the flow stress of the rolled metal. In other words, the microstructural changes, the mechanical properties as well as the final dimensions of the product and roll-force depend on the temperature distribution within the metal being rolled. In this paper, a mathematical model based on the finite element method is utilized to predict the temperature distribution and microstructural changes during the continuous hot slab rolling process. The effects of various parameters such as the heat of deformation, the work-roll temperature, the rolling speed, and the heat transfer coefficient between the work-roll and the metal are all taken into account in the analyses. To verify the validity of the model and the generated computer code, a comparison is carried out between the theoretical and plant-recorded results.

  5. IMPROVING ENERGY EFFICIENCY VIA OPTIMIZED CHARGE MOTION AND SLURRY FLOW IN PLANT SCALE SAG MILLS

    Energy Technology Data Exchange (ETDEWEB)

    Raj K. Rajamani; Sanjeeva Latchireddi; Sravan K. Prathy; Trilokyanath Patra

    2005-12-01

    The U.S. mining industry operates approximately 80 semi-autogenesis grinding mills (SAG) throughout the United States. Depending on the mill size the SAG mills draws between 2 MW and 17 MW. The product from the SAG mill is further reduced in size using pebble crushers and ball mills. Hence, typical gold or copper ore requires between 2.0 and 7.5 kWh per ton of energy to reduce the particle size. Considering a typical mining operation processes 10,000 to 100,000 tons per day the energy expenditure in grinding is 50 percent of the cost of production of the metal. A research team from the University of Utah is working to make inroads into saving energy in these SAG mills. In 2003, Industries of the Future Program of the Department of Energy tasked the University of Utah team to build a partnership between the University and the mining industry for the specific purpose of reducing energy consumption in SAG mills. A partnership was formed with Cortez Gold Mines, Kennecott Utah Copper Corporation, Process Engineering Resources Inc. and others. In the current project, Cortez Gold Mines played a key role in facilitating the 26-ft SAG mill at Cortez as a test mill for this study. According to plant personnel, there were a number of unscheduled shut downs to repair broken liners and the mill throughput fluctuated depending on ore type. The University team had two softwares, Millsoft and FlowMod to tackle the problem. Millsoft is capable of simulating the motion of charge in the mill. FlowMod calculates the slurry flow through the grate and pulp lifters. Based on this data the two models were fine-tuned to fit the Cortez SAG will. In the summer of 2004 a new design of shell lifters were presented to Cortez and in September 2004 these lifters were installed in the SAG mill. By December 2004 Cortez Mines realized that the SAG mill is drawing approximately 236-kW less power than before while maintaining the same level of production. In the first month there was extreme cycling

  6. Damage evolution assessment and modeling for CBN grinding wheel wear

    OpenAIRE

    YU, TIANYU; Bastawros, Ashraf F; Chandra, Abhijit

    2014-01-01

    The wear rate of a grinding wheel directly affects the workpiece surface integrity and tolerances. This paper summarizes a combined experimental-modeling framework for life expectancy of an electroplated Cubic Boron Nitride (CBN) grinding wheel, typically utilized in nickel-based superalloy grinding. The article presents an experimental framework to facilitate the formulation of a micromechanics based modeling framework. The presented study investigates the topological evolution of the grindi...

  7. 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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  9. Separate critical condition for ultrasonic vibration assisted grinding

    Institute of Scientific and Technical Information of China (English)

    ZHANG Hong-li; ZHANG Jian-hua

    2009-01-01

    Separate characteristic of the tangential ultrasonic vibration assisted grinding(TUAG)machining is analyzed based on TUAG process, and a critical speed formula is given to correctly set the machining parameters to insure the separate characteristics of TUAG process. The critical speed is not only related to the ultrasonic vibration amplitude and frequency, but also to the grinding wheel velocity and the cutting point space, and the grinding force can be decreased during the TUAG process with separability. Grinding force experiments are conducted, and the experimental results are in good agreement with the theoretical results.

  10. Study on the New Grinding Fluids of Oils on Water

    Institute of Scientific and Technical Information of China (English)

    魏源迁; 钱怡; 中村隆; 松原十三生

    2003-01-01

    To fulfill a zero-emission in the process of grinding and thoroughly eliminate the influences of the conventional grinding fluids on the eco-environment as well as save up electric energy and reduce in production costs, the new grinding fluids of botanic oils on water were developed, in which a lot of tiny water droplets attached with micro oil films were blown to the machining area by a compressing air-jet so good as to produce lubricating and cooling roles.In this study, grinding performances of the new fluids were investigated by comparison to the conventional ones such as emulsion on the plane NC grinder.

  11. Cam Profile Grinding CNC System Based on Open Architecture

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper studies some key technologies of CNC system for cam grinding. Themathematical motion model for cam grinding is established according to the harmony of re-ciprocating motion of the grinding wheel and the rotating motion of the woorkpiece. Themethod of using the linear servomotor to accomplish the grinding wheel tracking is devel-oped and the dynamic model of the system is analyzed. Then the cross-coupled biaxial errorcompensation model is proposed. Finally,the hardware and software of the control systemare designed based on open architecture. Some algorithms, such as spline fitting and inter-polation for cam contour, velocity control and feed control, are presented to improvegrinding precision.

  12. Thermo-mechanical properties of bowl-shaped grinding wheel and machining error compensation for grinding indexable inserts

    Institute of Scientific and Technical Information of China (English)

    张祥雷; 姚斌; 陈彬强; 孙维方; 王萌萌; 罗琪

    2015-01-01

    In order to meet the technical requirements of grinding the circumferential cutting edge of indexable inserts, thermo-mechanical properties of bowl-shaped grinding wheel in high speed grinding process and the influence of dimension variations of the grinding wheel on machining accuracy were investigated. Firstly, the variation trends of the dimension due to centrifugal force generated in different wheel speeds were studied and the effect of stress stiffening and spin softening was presented. Triangular heat flux distribution model was adopted to determine temperature distribution in grinding process. Temperature field cloud pictures were obtained by the finite element software. Then, dimension variation trends of wheel structure were acquired by considering the thermo-mechanical characteristic under combined action of centrifugal force and grinding heat at different speeds. A method of online dynamic monitoring and automatic compensation for dimension error of indexable insert was proposed. By experimental verification, the precision of the inserts satisfies the requirement of processing.

  13. Quality Control system for a hot-rolled metal surface

    Directory of Open Access Journals (Sweden)

    I. Mazur

    2016-07-01

    Full Text Available The modern ideas about of quality of products are based on the principle of the absolute satisfaction of requirements of recommendations of the buyer. A presence of surface defects of steel-smelting and rolling origin is peculiar to 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 surfaces of the flat bar, block of illumination of the upper and lower surfaces of the flat bar, computer equipment. A system that secures 100 % control of the surface of rolled metal (of the upper and lower side detects automatically and classifies the sheet defects in the real time mode was mounted in the domestic practice in the first time in 2003 on hot rolling mill 2000 JSC «Novolipetsk Iron & Steel Corporation» (NISC. The whole assortment of the mill 2000 was divided for the five groups by the outward appearance of the surface. The works on the identification of defects of hot-rolled metal and widening of data base of knowledge of ASIS were continued after the carrying out of guarantee tests. More than 10 thousand images of defects were added to the data base during the year.

  14. Rolling Force Prediction in Heavy Plate Rolling Based on Uniform Differential Neural Network

    Directory of Open Access Journals (Sweden)

    Fei Zhang

    2016-01-01

    Full Text Available Accurate prediction of the rolling force is critical to assuring the quality of the final product in steel manufacturing. Exit thickness of plate for each pass is calculated from roll gap, mill spring, and predicted roll force. Ideal pass scheduling is dependent on a precise prediction of the roll force in each pass. This paper will introduce a concept that allows obtaining the material model parameters directly from the rolling process on an industrial scale by the uniform differential neural network. On the basis of the characteristics that the uniform distribution can fully characterize the solution space and enhance the diversity of the population, uniformity research on differential evolution operator is made to get improved crossover with uniform distribution. When its original function is transferred with a transfer function, the uniform differential evolution algorithms can quickly solve complex optimization problems. Neural network structure and weights threshold are optimized by uniform differential evolution algorithm, and a uniform differential neural network is formed to improve rolling force prediction accuracy in process control system.

  15. Quenching simulation of steel grinding balls

    Energy Technology Data Exchange (ETDEWEB)

    Zapata-Hernandez, O.; Reyes, L. A.; Camurri, C.; Carrasco, C.; Garza-Monte-de-Oca, F.; Colas, R.

    2015-07-01

    The phase transformations of high carbon steel during quenching and equalizing were modelled using commercial computer packages based on the finite element method and the kinetic transformation of steel. The model was used to predict the temperature and microstructural changes taking place within balls of two different sizes that are used for grinding mineral ores. A good correlation between the temperatures measured by inserted thermocouples and those predicted by the model was obtained after modifying the thermal conductivity of the steel within the temperature domain at which mixed phases are present. The phase transformations predicted were confirmed by metallographic analyses. (Author)

  16. High coercivity induced by mechanical milling in cobalt ferrite powders

    International Nuclear Information System (INIS)

    In this work we report a study of the magnetic behavior of ferrimagnetic oxide CoFe2O4 treated by mechanical milling with different grinding balls. The cobalt ferrite nanoparticles were prepared using a simple hydrothermal method and annealed at 500 °C. The non-milled sample presented coercivity of about 1.9 kOe, saturation magnetization of 69.5 emu/g, and a remanence ratio of 0.42. After milling, two samples attained coercivity of 4.2 and 4.1 kOe, and saturation magnetization of 67.0 and 71.4 emu/g respectively. The remanence ratio MR/MS for these samples increase to 0.49 and 0.51, respectively. To investigate the influence of the microstructure on the magnetic behavior of these samples, we used X-ray powder diffraction (XPD), transmission electron microscopy, and vibrating sample magnetometry. The XPD analysis by the Williamson–Hall plot was used to estimate the average crystallite size and strain induced by mechanical milling in the samples. - Highlights: • Magnetic behavior of milled CoFe2O4 is studied. • The coercivity is increase of about 150%. • The remanence ratio are increase to all milled samples. • The strain and pinning effects are observed in milled samples

  17. Frequency Modulation of High-Speed Mill Chatter

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Mill chatter is a common phenomenon in the metal strip rolling process. Product defects caused by mill vibration were reported worldwide during last two decades, which is usually classified as torque vibration of the driving system with low frequencies and vertical vibration of the mill stand with comparative higher frequencies. The frequency range of the vertical vibration is wide (in general from more than 100 Hz to more than 1 000 Hz), and the vibration phenomena are very complex, even it is very diffic...

  18. Optimization Study on the Cyanide Grinding Leaching Process%氰化磨矿浸出工艺优化试验研究

    Institute of Scientific and Technical Information of China (English)

    徐忠敏; 沈述保; 李学强; 叶树峰

    2013-01-01

    To break the traditional grinding,grading and leaching process in the existing production of the cyanide,and to achieve the goal of improving the grinding efficiency,cyanide recovery and reduce production energy consumption,the experimental research of cyanide grinding leaching process for the Jinchiling gold deposit was conducted.Through comparing the mineral one-time grinding leaching experiment and piecewise grinding leaching experiment,founding that mineral one-time grinding to qualified fineness (-400 mesh fineness up to 90%),leaching 12 h,cyanide recovery rate can reach 99.5%.Stage grinding sectional leaching time grinding fineness of -400 accounted for 75%,an extraction time is 16 h,after the classification +400 regrinding fineness was 91%,the extraction time is 12 h,the total recovery rate up to 99.64%.Stage grinding leaching mill total energy saving is about 15%,cyaniding recovery rate can be increased by 0.14%,saving energy and improving the recovery rate from the perspective of stage grinding leaching is good.%为了打破现有氰化生产中传统磨矿、分级及浸出工艺,达到提高磨矿效率、氰化回收率和降低生产能耗的目标,金翅岭金矿进行氰化磨矿浸出工艺的优化试验研究,通过对矿物进行一次性磨矿浸出试验与分段磨矿浸出试验对比发现,矿物一次性磨矿至合格细度-400目细度达到90%,浸出12 h时,氰化回收率可达到99.5%;分段磨矿分段浸出一次磨矿细度为-400目占75%,一次浸出时间为16 h,分级后+400目再磨细度为91%,浸出时间为12 h时,总回收率可达99.64%。分段磨矿浸出磨机节约能耗约15%,氰化回收率提高0.14%。

  19. 30 CFR 56.14115 - Stationary grinding machines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Stationary grinding machines. 56.14115 Section 56.14115 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Equipment Safety Devices and Maintenance Requirements § 56.14115 Stationary grinding machines....

  20. Occlusal Grinding Pattern during Sleep Bruxism and Temporomandibular Disorder

    Directory of Open Access Journals (Sweden)

    Yeni Wijaya

    2013-09-01

    Full Text Available Sleep Bruxism is a significant etiology of temporomandibular disorder (TMD and causes many dental or oral problems such as tooth wear or facet. There is no study analyzing the relationship between sleep bruxism and TMD. Objective: To investigate any relationship between occlusal grinding pattern during sleep bruxism and temporomandibular disorder. Methods: A cross-sectional study involving 30 sleep bruxism patients attended the Faculty Dentistry Universitas Indonesia Teaching Hospital (RSGMP FKG UI. Completion of 2 forms of ID-TMD index and questionnaire from American Academy of Sleep Medicine were done. BruxChecker was fabricated and used for two nights to record the occlusal grinding pattern. The occlusal grinding pattern was categorized into laterotrusive grinding (LG and mediotrusive side. Further divisons of LG were: incisor-canine (IC, incisor-caninepremolar (ICP and incisor-canine-premolar-molar (ICPM. Mediotrusive side was classified as mediotrusive contact (MC and mediotrusive grinding (MG. Results: It was found that occlusal grinding pattern in non-TMD subjects were IC+MC, in subjects with mild TMD were ICP+MG and in subjects with moderate TMD were ICP+MG and ICPM+MG. TMJ was more significantly affected by ICP and ICPM grinding pattern than that of IC. Conclusion: There was a significant relationship between occlusal grinding pattern during sleep bruxism and TMD.DOI: 10.14693/jdi.v20i2.149

  1. Hybrid Hot Strip Rolling Force Prediction using a Bayesian Trained Artificial Neural Network and Analytical Models

    Directory of Open Access Journals (Sweden)

    Abdelkrim Moussaoui

    2006-01-01

    Full Text Available The authors discuss the combination of an Artificial Neural Network (ANN with analytical models to improve the performance of the prediction model of finishing rolling force in hot strip rolling mill process. The suggested model was implemented using Bayesian Evidence based training algorithm. It was found that the Bayesian Evidence based approach provided a superior and smoother fit to the real rolling mill data. Completely independent set of real rolling data were used to evaluate the capacity of the fitted ANN model to predict the unseen regions of data. As a result, test rolls obtained by the suggested hybrid model have shown high prediction quality comparatively to the usual empirical prediction models.

  2. Computer Simulation of Batch Grinding Process Based on Simulink 5.0

    Institute of Scientific and Technical Information of China (English)

    LI Xia; YANG Ying-jie; DENG Hui-yong; HUANG Guang-yao

    2005-01-01

    How to use Simulink software in grinding system was studied. The method of designing batch grinding subsystem and the steps of building batch grinding blockset were introduced. Based on batch grinding population balance model, batch grinding was simulated with Simulink. The results show that the simulation system designed with Simulink explain reasonably the impersonal rule of batch grinding. On the basis of batch grinding simulation, the computer simulation of mineral processing system with Simulink of grinding and classification, comminution, etc, can be properly explored.

  3. Dynamical aspects in modeling long cantilevering workpieces in tool grinding

    Science.gov (United States)

    de Payrebrune, K. M.; Kröger, M.

    2015-10-01

    Tool grinding is a complex process in which temporal dynamics of workpiece and grinding wheel, and the material removal process itself, affect the quality of the workpiece. Many existing models already provide the option to study the dynamics of workpiece and grinding wheel or cutting forces and material removal processes, but mostly do not combine these aspects. Here, workpiece dynamics are studied in relation to its structural and geometrical changing properties during machining, and are used to simulate the vibrations and deformation of the workpiece during grinding. In combination with models for the grinding wheel and the material removal process, dependencies of the workpiece dynamics on the workpieces quality are studied and results from this hybrid model are in excellent agreement with empirical measurements. Furthermore, the results demonstrate the significant effects of deformations of the workpiece on its final geometry.

  4. Three-dimensional measurement and characterization of grinding tool topography

    Science.gov (United States)

    Cui, Changcai; Blunt, Liam; Jiang, Xiangqian; Xu, Xipeng; Huang, Hui; Ye, Ruifang

    2013-01-01

    A comprehensive 3-dimensional measurement and characterization method for grinding tool topography was developed. A stylus instrument (SOMICRONIC, France) was used to measure the surface of a metal-bonded diamond grinding tool. The sampled data was input the software SurfStand developed by Centre for Precision Technology (CPT) for reconstruction and further characterization of the surface. Roughness parameters pertaining to the general surface and specific feature parameters relating to the grinding grits, such as height and angle peak curvature have been calculated. The methodology of measurement has been compared with that using an optical microscope. The comparison shows that the three-dimensional characterization has distinct advantages for grinding tool topography assessment. It is precise, convenient and comprehensive so it is suitable for precision measurement and analysis where an understanding of the grinding tool and its cutting ability are required.

  5. Specific Properties of Air Flow Field Within the Grinding Zone

    Institute of Scientific and Technical Information of China (English)

    ZHENG Junyi; JIANG Zhengfeng; ZHAO Liang

    2006-01-01

    Air barrier of grinding means a boundary layer of air existing at the circumference of the rotating wheel, which hinders coolant from entry. This paper makes a research on air flow field of the grinding zone through experiments and numerical simulations, focusing on acquainting with the specific properties of the air flow field. Finite volume method is applied to analyze air flow field within grinding wheel in the course of numerical calculations. The test devices such as Hot-wire anemometer and Betz manometer are used during the experiments of testing the pressure and velocity within grinding zone. Results of experiments agree by and large with numerical results of calculations. The conclusions obtained in this paper, the distribution of wall pressure and the distribution of air flow velocity, are important and useful to navigate the delivery of coolant into the grinding zone. In conclusion, some recommendations are made for further study and practical applications in such field.

  6. Monitoring Grinding Wheel Redress-life Using Support Vector Machines

    Institute of Scientific and Technical Information of China (English)

    Xun Chen; Thitikorn Limchimchol

    2006-01-01

    Condition monitoring is a very important aspect in automated manufacturing processes. Any malfunction of a machining process will deteriorate production quality and efficiency. This paper presents an application of support vector machines in grinding process monitoring. The paper starts with an overview of grinding behaviour. Grinding force is analysed through a Short Time Fourier Transform (STFT) to identify features for condition monitoring. The Support Vector Machine (SVM) methodology is introduced as a powerful tool for the classification of different wheel wear situations.After training with available signal data, the SVM is able to identify the state of a grinding process. The requirement and strategy for using SVM for grinding process monitoring is discussed, while the result of the example illustrates how effective SVMs can be in determining wheel redress-life.

  7. 升速轧制对热轧带钢层流冷却出口温度的影响%Influence of Accelerating Rolling on the Laminar Cooling Exit Temperature in Hot Strip Mill

    Institute of Scientific and Technical Information of China (English)

    张大志; 叶海丽; 项晓菲; 谢新亮; 李红霞; 高广

    2012-01-01

    采用传热学原理建立了层流冷却温度有限差分模型,并用现场实测数据对水冷换热系数进行了自适应修正.对德盛1 150 mm热轧带钢层流冷却过程的温度变化进行了数值模拟,建立了一套层流冷却温度仿真系统,分析和研究升速轧制时带钢在层流冷却中温度变化的趋势.结果表明,层冷出口温度受带钢的速度影响较大,在升速过程中,如果不采用集管动态喷水调节,带钢温度出现前低后高的现象,并且随着加速度的增加带钢前后温差越大.以此为依据,现场过程自动化系统L2级硬件采用过程服务器,基础自动化系统L1级硬件采用西门子PLC,L2级和L1级软件分别在C++和Step7V5.4下编程实现,并采用了带钢头尾宏跟踪和过程自动化系统采用带钢样本微跟踪的控制策略,对处于变速及高速运动中的带钢沿长度方向逐点实施控制,用动态调节的冷却集管系统来保证在速度变化期间带钢层流冷却出口温度的稳定性.%The principle of heat transfer is adopted for the strip temperature finite difference model and the heat transfer coefficient of water is amended based on measured data.The temperature change is numerically simulated in the process of Desheng 1 150 mm hot strip laminar cooling.The simulation system is established to study the change trend of laminar cooling temperature in accelerating rolling.Results show that the coil temperature is significantly influenced by the speed of strip,the strip temperature gradually increases from the front to the back,and the temperature deviation increases with the acceleration without dynamic regulation of the cooling pipe system during acceleration.Based on the conclusions,the L2-level hardware is a process server,the L1-level hardware is Siemens PLC for the online control system and the softwares of L1 and L2 are programmed by C++ and Step7V54.The successful control strategy online tracking of head and tail of

  8. Wet gringing of zeolite in stirred media mill

    Science.gov (United States)

    Mucsi, G.; Bohács, K.

    2016-04-01

    In the present study the results of systematic experimental series are presented with the specific goal of optimizing the zeolite nanoparticles' production using a wet stirred media mill. The diameter of the grinding media as well as the rotor velocity were varied in the experiments. Particle size distribution and "outer" specific surface area of the ground samples were measured by a laser particle size analyser. Additionally, BET, XRD and FT-IR analyses were performed for the characterization of the "total" specific surface area as well as the crystalline and material structure, respectively. Based on the results of the laboratory experiments it was found that wet stirred media milling provided significant reductions in the particle size of zeolite. Furthermore, the crystallinity of the samples also decreased, so not only the physical but the mineralogical characteristics of zeolite can be controlled by stirred media milling.

  9. Third Rolling Mill in a Factory Improvement Project 6 kV Reactive Power Compensation and Harmonic Control%某厂改造工程6kV供电系统无功补偿与谐波治理

    Institute of Scientific and Technical Information of China (English)

    刘义友; 吴方达; 徐芸; 刘宾

    2011-01-01

    High-power rectifier.inverter,energy-saving lamp etc equipment can produce large amounts harmonic current, and influence the normal operation of the equipment. Combined with the power play the flat line load characteristics, overviewed the third rolling mill in a factory 6 kV power system improvement project reactive power compensation and harmonic design. The scheme select high-pressure FC type filter and reactive compensation device to make the harmonic current most inflows filter circuits. After analysis and calculation, the actual filter effect proof the effect is obvious, after running,can absorb the most harmonic,can raise grid power factor, less investment, high economic benefit.%大功率的整流器、变频器、节能灯等设备会产生大量谐波电流,影响设备的正常运行,结合弹扁生产线的用电负荷特点,概述了某厂改造工程6 kV供电系统无功补偿与谐波治理的设计方案,该方案选用高压FC型滤波及无功补偿装置,使谐波电流大部分流入滤波回路.经过分析计算,投运后滤波效果实测证明效果明显,能够将谐波大部分吸收,同时还提高电网功率因数,投资少,经济效益高.

  10. Influence of Hot Deformation and Subsequent Austempering on the Mechanical Properties of Hot Rolled Multiphase Steel

    Institute of Scientific and Technical Information of China (English)

    Zhuang LI; Di WU

    2006-01-01

    Influence of hot deformation and subsequent austempering on the mechanical properties of hot rolled multiphase steel was investigated. Thermo-mechanical control processing (TMCP) was conducted by using a laboratory hot rolling mill, where three different kinds of finishing rolling reduction, and austemperings with various isothermal holding duration were applied. The results have shown that a multiphase microstructure consisting of polygonal ferrite, granular bainite and larger amount of stabilized retained austenite can be obtained by controlled rolling processes. Mechanical properties increase with increasing the amount of deformation because of the stabilization of retained austenite. Ultimate tensile strength (σb), total elongation (δ)36% and 28476 MPa%, respectively) at optimal processes.

  11. Simulation of Hot Strip-Rolling Process Based on Dislocation Density Variation

    Institute of Scientific and Technical Information of China (English)

    XIAO Hong; ZHANG Guo-min; CHEN Zhan-fu

    2004-01-01

    Based on the variation of dislocation density, which is influenced by rolling variables in hot strip-rolling process, a yield stress model was constructed. An integrated model was built to predict the temperature variation and microstructure evolution, in which the Orowan formula was used to calculate the stress and strain, and the finite difference method was adopted to determine the temperature field. This model was applied to predict the temperature variation, austenite grain size and phase transformation in hot strip-rolling process, and the prediction results are in good agreement with the measured ones on 2 050 mm continuous hot strip-rolling mill.

  12. Effect of Mechanical Grinding and Ionic Liquid Pre-Treatment on Oil Palm Frond

    International Nuclear Information System (INIS)

    The present study was set to investigate the chemical structural group of different particle size of Oil palm frond (OPF) after mechanical and Ionic liquid (IL) pretreatment by FTIR analysis. The particle sizes range of biomass used were 0-75, 75-125, 125-180, 180-250 and 250-355 μm which were prepared through mechanical grinding process by using an analytical mill. IL used in this experiment was 1-ethyl-3-methylimidazolium chloride [EMIM][Ac] with two different concentration of 1M and 3M. Pretreatment by IL was done on BioshakeIQ for 3 hours at 800 rpm and 85 degree Celsius. The pretreated OPF was then analyzed using FTIR spectroscopy in order to evaluate the performance of mechanical grinding and IL pretreatment based on the change observed in chemical structure through functional group existed. It was found that after size reduction through grinding process, the spectra between all particle sizes obtained did not differ much except for particle size range of 75-125 μm. The particle size range showed on much characteristics of cellulose due to the broad peak within the 3600-3100 cm-1 which stand for O-H bonding. However, when the FTIR spectra were compared between before and after IL pretreatments, there were some different in peaks trend which explained there were some chemical structure changes within the OPF samples. There were some appearances and disappearances of certain peak were observed after the IL pretreatment especially the peak at band near 1700 cm-1 and 1550 cm-1. (author)

  13. PROFILE AND FLATNESS CONTROL SYSTEM IN 1 700 mm HOT STRIP MILLS OF ANSTEEL

    Institute of Scientific and Technical Information of China (English)

    HE Anrui; YANG Quan; CHEN Xianlin; ZHAO Lin

    2008-01-01

    Varying contact-length backup roll and linearly variable crown work roll are provided for improving the mill performance of profile and flatness control. Integrated with theses technologies, relevant profile and flatness control models are developed for hot strip mills on the basis of large amount of finite element calculation. These models include shape setup control model in process control system, bending force feedforward control model, crown feedback control model and flatness feedback control model in basis automation system. Such a profile and flatness control system with full functions is applied in 1 700 mm industrial hot strip mills of Ansteel. Large amount of production data shows that the crown precision with the tolerance of (18 (m is over 90%, the strip percentage which the actual flatness is within ( 25 I-unit surpasses 96%, and general roll consume is reduced by 28% by using the profile and flatness control system. In addition, schedule-free rolling is realized.

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

    Directory of Open Access Journals (Sweden)

    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.

  15. Investigation on drilling-grinding of CFRP

    Institute of Scientific and Technical Information of China (English)

    Yanming QUAN; Wenwang ZHONG

    2009-01-01

    It is difficult to machine polymer matrix composites reinforced by carbon fibre, and the hole-making process is the most necessary machining process for composite plate products. Conventional drills have a very short life in the drilling of this kind of composites and the quality of the hole is very poor. In this paper, the cemented or plated diamond core tools are tested to make holes in carbon fibre/epoxy composite plates. The effects of machining parameters, cooling and chip removal on the tool life, and the hole quality are investigated. The results indicate that the material removal mechanism of the two kinds of diamond tools is not like the cutting effect of the conventional drilling but similar to that of grinding. Satisfactory effects in making holes in the composites are obtained--quite acceptable machined hole quality, low costs, and long wear-resistant endurance.

  16. Modelling and simulation of fixtures during grinding

    Institute of Scientific and Technical Information of China (English)

    Matthias KLAERNER; Juergen LEOPOLD; Lothar KROLL

    2009-01-01

    The complex workpiece-fixture behaviour during machining is an essential component of the fixture development process. In detail, the forces acting on fixture components have to be analysed. A method for the prediction of the reaction forces due to process and clamping loads is presented in this article.At the beginning, detailed information about the workpiece-fixture behaviour during the process is determined by a complex finite element model. Secondly, the reduction of the number of elements leads to a smaller model with less computation time, validated and used for the variation of process parameters. Finally, an analytical description is developed based on the combination of both results.With the help of the empiric equation it is possible to predict the reaction forces and the dependency on several process parameters. This method has been validated by modelling shape grinding of a nozzle guide vane.

  17. The Grinding Wheel Performance in the Transverse Cylindrical Grinding of an Eutetic Alloy

    Directory of Open Access Journals (Sweden)

    Bianchi Eduardo Carlos

    2002-01-01

    Full Text Available This paper presents a research in which the performance of two different grinding wheels (a conventional and a CBN wheel was evaluated in a transverse cylindrical grinding of a eutectic alloy. Three cutting conditions were tested: rough, semi-finishing and finishing. As evaluating parameters, the cutting force, the roughness and the wheel wear were measured. As a result, the best values of the cutting force and the roughness were obtained when grinding with the conventional wheel, due to the best dressing operation performed, for all the cutting conditions. The CBN presented the best G ratio values. Although, the G ratio values observed for the CBN wheel were lower than the expected one due to the non-effective dressing operation applied. In the conditions tested, in terms of cutting force and roughness, the conventional wheel is the best choice. In terms of G ratio, a cost analysis is crucial to determine if the differences observed among the wheels can justify the use of the CBN wheel. In a positive case, the dressing operation must be improved.

  18. Experimental Studies on Ultrasonic Vibration Grinding of the Workpiece Made from Fine-crystalline Zirconia Ceramics

    Institute of Scientific and Technical Information of China (English)

    WU Yan; ZHU Xun-sheng; ZHAO Bo

    2006-01-01

    The performances of fine-crystalline zirconia ceramics in workpiece ultrasonic vibration grinding (WUVG) and conventional grinding (CG) with diamond wheel were researched. The effects of WUVG and CG on material removal rate, grinding forces, surface roughness and microstructure of zirconia ceramic were investigated.Experimental results indicated that: (1) The material removal rate (MRR) in ultrasonic grinding process is two times as large as that of in conventional grinding. The material removal rate increases with increasing grinding depth in both ultrasonic grinding and conventional grinding.(2) The ultrasonic vibration grinding force is lower than that of conventional grinding force, and the increase of the worktable speed leads to a decrease of the grinding force,while the grinding force increases with larger grinding depth in both WUVG and CG. (3) The surface of ultrasonic vibration grinding has no spur and build-up edge and its surface roughness is smaller than that of CG significantly.Surface quality of WUVG is superior to that of conventional grinding, it is easy for ultrasonic vibration grinding that material removal mechanism is ductile grinding.

  19. Rolling Shutter Motion Deblurring

    KAUST Repository

    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.

  20. Grinding temperature and energy ratio coe cient in MQL grinding of high-temperature nickel-base alloy by using di erent vegetable oils as base oil

    Institute of Scientific and Technical Information of China (English)

    Li Benkai; Li Changhe; Zhang Yanbin; Wang Yaogang; Jia Dongzhou; Yang Min

    2016-01-01

    Vegetable oil can be used as a base oil in minimal quantity of lubrication (MQL). This study compared the performances of MQL grinding by using castor oil, soybean oil, rapeseed oil, corn oil, sunflower oil, peanut oil, and palm oil as base oils. A K-P36 numerical-control precision surface grinder was used to perform plain grinding on a workpiece material with a high-temperature nickel base alloy. A YDM–III 99 three-dimensional dynamometer was used to measure grinding force, and a clip-type thermocouple was used to determine grinding temperature. The grinding force, grind-ing temperature, and energy ratio coefficient of MQL grinding were compared among the seven veg-etable oil types. Results revealed that (1) castor oil-based MQL grinding yields the lowest grinding force but exhibits the highest grinding temperature and energy ratio coefficient;(2) palm oil-based MQL grinding generates the second lowest grinding force but shows the lowest grinding temperature and energy ratio coefficient;(3) MQL grinding based on the five other vegetable oils produces similar grinding forces, grinding temperatures, and energy ratio coefficients, with values ranging between those of castor oil and palm oil;(4) viscosity significantly influences grinding force and grinding tem-perature to a greater extent than fatty acid varieties and contents in vegetable oils;(5) although more viscous vegetable oil exhibits greater lubrication and significantly lower grinding force than less vis-cous vegetable oil, high viscosity reduces the heat exchange capability of vegetable oil and thus yields a high grinding temperature;(6) saturated fatty acid is a more efficient lubricant than unsaturated fatty acid;and (7) a short carbon chain transfers heat more effectively than a long carbon chain. Palm oil is the optimum base oil of MQL grinding, and this base oil yields 26.98 N tangential grinding force, 87.10 N normal grinding force, 119.6 °C grinding temperature, and 42.7%energy ratio coefficient

  1. Agar agar-stabilized milled zerovalent iron particles for in situ groundwater remediation.

    Science.gov (United States)

    Velimirovic, Milica; Schmid, Doris; Wagner, Stephan; Micić, Vesna; von der Kammer, Frank; Hofmann, Thilo

    2016-09-01

    Submicron-scale milled zerovalent iron (milled ZVI) particles produced by grinding macroscopic raw materials could provide a cost-effective alternative to nanoscale zerovalent iron (nZVI) particles for in situ degradation of chlorinated aliphatic hydrocarbons in groundwater. However, the aggregation and settling of bare milled ZVI particles from suspension presents a significant obstacle to their in situ application for groundwater remediation. In our investigations we reduced the rapid aggregation and settling rate of bare milled ZVI particles from suspension by stabilization with a "green" agar agar polymer. The transport potential of stabilized milled ZVI particle suspensions in a diverse array of natural heterogeneous porous media was evaluated in a series of well-controlled laboratory column experiments. The impact of agar agar on trichloroethene (TCE) removal by milled ZVI particles was assessed in laboratory-scale batch reactors. The use of agar agar significantly enhanced the transport of milled ZVI particles in all of the investigated porous media. Reactivity tests showed that the agar agar-stabilized milled ZVI particles were reactive towards TCE, but that their reactivity was an order of magnitude less than that of bare, non-stabilized milled ZVI particles. Our results suggest that milled ZVI particles could be used as an alternative to nZVI particles as their potential for emplacement into contaminated zone, their reactivity, and expected longevity are beneficial for in situ groundwater remediation. PMID:26596889

  2. 转速率对磨矿细度的影响%INFLUENCE OF ROTATION RATE ON GRINDING FINENESS

    Institute of Scientific and Technical Information of China (English)

    尹海; 庄故章; 王春梅

    2013-01-01

    Inverter is adopted in this article to change rotation rate of ball mill to implement milling experimental study of Dahongshan Copper Mine to explore the relationship of the rotation rate and the grinding fineness. With the rotation rate increases, - 0. 074mm size fraction production increases to the maximum and then decreases.%本文采用变频器改变球磨机转速,对大红山铜矿进行磨矿试验研究,探求转速率与磨矿细度的关系.随着转速率的增大,-0.074 mm粒级产率先增大到最大值,然后逐渐减小.

  3. Environmental Impact of Electricity Consumption in Crushing and Grinding Processes of Traditional and Urban Gold Mining by Using Life Cycle Assessment (LCA

    Directory of Open Access Journals (Sweden)

    Nur Rafidah Yahaya

    2012-01-01

    Full Text Available Mining is not only an essential component of social and economic development since prehistoric time, but it also gives a large impact on our civilization. Gold is a noble metal that is highly valued. The extraction of minerals from earth is known as traditional mining. Gold also can be extracted from electronic waste or e-waste, and this new concept is called urban mining. There are many stages in traditional and urban mining process. However, in this study, the focus was on crushing and grinding processes to produce 1 kg of gold. Crushing and grinding are processes in the milling stage. This research evaluates and compares the environmental impacts of crushing and grinding processes, based on electricity consumption. About 50 to 65% of total electricity in milling was used for crushing and grinding processes. Life Cycle Assessment (LCA methodology was used as a tool to evaluate the environmental burdens of electricity usage in converting ore and electronic waste to gold bars. The Life Cycle Impact Assessment (LCIA of this process was interpreted by using Eco-indicator 99 assessment methods in SimaPro software. The impact categories included in this study were carcinogens, respiratory organics, respiratory inorganics, radiation, climate change, ozone layer, ecotoxicity, acidification or eutrophication, land use and minerals. The results showed that crushing and grinding from traditional mining gave the largest impact to the environment with single score of 399 Pt compared to the urban mining with only 1.81 Pt score. The highest impact in both types of mining is to human health.

  4. Ultraprecision, high stiffness CNC grinding machines for ductile mode grinding of brittle materials

    Science.gov (United States)

    McKeown, Patrick A.; Carlisle, Keith; Shore, Paul; Read, R. F.

    1990-10-01

    Under certain controlled conditions it is now possible to machine brittle materials such as glasses and ceramics using single or multi-point diamond tools (grinding), so that material is removed by plastic flow, leaving crack-free surfaces. This process is called 'shear' or 'ductile' mode grinding. It represents a major breakthrough in modern manufacturing engineering since it promises to enable: - complex optical components, both transmission and reflecting to be generated by advanced CNC machines with very little (or even zero) subsequent polishing. - complex shaped components such as turbine blades, nozzle guide vanes, etc. to be finish machined after near net shape forming, to high precision in advanced ceramics such as silicon nitride, without inducing micro-cracking and thus lowering ultimate rupture strength and fatigue life. Ductile mode "damage free" grinding occurs when the volume of materials stressed by each grit of the grinding wheel is small enough to yield rather than exhibit brittle fracture, i.e. cracking. In practice, this means maintaining the undeformed chip thickness to below the ductile-brittle transition value; this varies from material to material but is generally in the order of 0.1 pm or 100 nm, (hence the term "nanogrinding" is sometimes used) . Thus the critical factors for operating successfully in the ductile regime are machine system accuracy and dynamic stiffness between each grit and the workpiece. In detail this means: (i) High precision 'truing' of the diamond grits, together with dressing of the wheel bond to ensure adequate ' openness'; (ii) Design and build of the grinding wheel spindle with very high dynamic stiffness; error motions, radial and axial, must be considerably less than 100 nfl. (iii) Design and build of the workpiece carriage motion system with very high dynamic stiffness; error motions, linear or rotary, must be well within 100 nm. (iv) Smooth, rumble-free, high-stiffness servo-drives controlling the motions

  5. Shape Control Simulation on 4-High CVC Mill

    Institute of Scientific and Technical Information of China (English)

    WANG Ying-rui; YUAN Jian-guang; LIU Hong-min

    2005-01-01

    The computation model of shape and crown on 4 high CVC mill was established by combining the stream surface strip element method for analyzing three-dimensional plastic deformation of strip and the influence coefficient method for elastic deformation of rolls,and the simulation of the shape and crown control on 4-high CVC hot strip mill was conducted.The simulated results indicate that the influence of the shifting of CVC work roll on shape and crown is very large,and the shifting of work roll can be used to preset shape and crown.The influence of the bending force of work roll on shape and crown is smaller,and it is suitable to use the bending force of work roll for shape and crown adjustment on line.With the increase of strip width,the exit crown of strip increases firstly and de creases then,and the roll gap becomes smoother increasingly.Meanwhile,the transverse difference of front tension stress decreases firstly and increases then.

  6. Numerical analysis of small recessed silicon carbide grinding wheels

    Directory of Open Access Journals (Sweden)

    M.J. Jackson

    2010-11-01

    Full Text Available Purpose: Silicon carbide grinding wheels are tools used in manufacturing industry to form precision componentsand continue to be used to increase production rates due to their ability to remove high volumes of material athigh speeds. There is a demand to increase the speed of rotation of the grinding wheel in order to achieve highremoval rates. The increase in speed creates a situation where the grinding machine and the operator are subjectedto a possible catastrophic failure of the wheel due to the stresses generated in the coarse brittle structure of thevitrified grinding wheel. The study focused on building and analyzing computer models of grinding wheels withrecessed features spinning at different rotational speeds. By employing a computational approach, it was possibleto determine the maximum principal stresses in the wheel together with the location of the stresses. The geometryof vitrified wheels considered included a plain-sided rotating wheel and a recessed rotating wheel.Design/methodology/approach: The paper shows how stresses and factors of safety are calculated in order topredict the bursting speeds of small recessed SiC grinding wheels. The main methods used include finite elementanalysis and mechanical testing of abrasive materials. The approach of the paper is to integrate the use of numericalanalysis techniques and experimental techniques to predict the safe operating conditions of SiC abrasive products.Findings: Calculations were conducted to determine maximum stress in parallel-sided and recessed cup wheels.Relevant factors of safety and bursting speed were also calculated and compared with experimental data. Thepaper proves the usefulness and applicability of a method developed for taking account of stress concentrationsat the recess of small cup-shaped silicon carbide grinding wheels.Research limitations/implications: The paper is limited to analyzing small recessed SiC grinding wheels.Further work should focus on large

  7. McCarter superfinish grinding for silicon -- an update.

    Energy Technology Data Exchange (ETDEWEB)

    Anthony, F.; Khounsary, A.; McCarter, D.; Krasnicki, F.; Tangedahl, M.

    2000-11-03

    A grinding technique, referred to as the McCarter Superfinish, for grinding large size optical components is discussed and certain surface characterization information about flatness and the relative magnitude of the subsurface damage in silicon substrates is reported. The flatness measurements were obtained with a Zygo surface analyzer, and the substrate damage measurements were made by x-ray diffraction and acid etching. Results indicate excellent control of flatness and fine surface finish. X-ray measurements show that the diamond wheels with small particle sizes used in the final phases of the grinding operation renders surfaces with relatively small subsurface damage.

  8. Eco-efficiency of grinding processes and systems

    CERN Document Server

    Winter, Marius

    2016-01-01

    This research monograph aims at presenting an integrated assessment approach to describe, model, evaluate and improve the eco-efficiency of existing and new grinding processes and systems. Various combinations of grinding process parameters and system configurations can be evaluated based on the eco-efficiency. The book presents the novel concept of empirical and physical modeling of technological, economic and environmental impact indicators. This includes the integrated evaluation of different grinding process and system scenarios. The book is a valuable read for research experts and practitioners in the field of eco-efficiency of manufacturing processes but the book may also be beneficial for graduate students.

  9. MECHANICAL GRINDING OF SOLID POWDER MATERIALS

    Directory of Open Access Journals (Sweden)

    Dmitrenko D. V.

    2015-10-01

    Full Text Available The article is dedicated to the determination of conditions for solid bodies’ fragmentation, providing minimal size of particles by means of their mechanical dispersion through the example of powders of titanium carbide (TiC, cubic boron nitride – borazon (CBN and boron carbide (B4C. The theoretical and practical aspects of the process of mechanical fragmentation of particles of solid powder materials in ball mill for their further utilization in furnace charge for high-speed gas-flame sputtering of wear-resistant composite materials are examined in the article. Methods of preliminary calculation of minimum allowable size of solid particles of powder materials during mechanical fragmentation, based upon Griffiths’ mechanical theory of rapture using experimental data for hardness of material and its yield are proposed and theoretically substantiated. There we have the results of experiments on mechanical fragmentation of titanium carbide in attritor, boron carbide and cubic boron nitride in centrifugal planetary mill, confirming correctness of theoretical propositions and calculations are set out. Recommendations on mechanical fragmentation of solid powder materials in ball mills are formulated as well

  10. Grinding temperature and energy ratio coefficient in MQL grinding of high-temperature nickel-base alloy by using different vegetable oils as base oil

    Directory of Open Access Journals (Sweden)

    Li Benkai

    2016-08-01

    Full Text Available Vegetable oil can be used as a base oil in minimal quantity of lubrication (MQL. This study compared the performances of MQL grinding by using castor oil, soybean oil, rapeseed oil, corn oil, sunflower oil, peanut oil, and palm oil as base oils. A K-P36 numerical-control precision surface grinder was used to perform plain grinding on a workpiece material with a high-temperature nickel base alloy. A YDM–III 99 three-dimensional dynamometer was used to measure grinding force, and a clip-type thermocouple was used to determine grinding temperature. The grinding force, grinding temperature, and energy ratio coefficient of MQL grinding were compared among the seven vegetable oil types. Results revealed that (1 castor oil-based MQL grinding yields the lowest grinding force but exhibits the highest grinding temperature and energy ratio coefficient; (2 palm oil-based MQL grinding generates the second lowest grinding force but shows the lowest grinding temperature and energy ratio coefficient; (3 MQL grinding based on the five other vegetable oils produces similar grinding forces, grinding temperatures, and energy ratio coefficients, with values ranging between those of castor oil and palm oil; (4 viscosity significantly influences grinding force and grinding temperature to a greater extent than fatty acid varieties and contents in vegetable oils; (5 although more viscous vegetable oil exhibits greater lubrication and significantly lower grinding force than less viscous vegetable oil, high viscosity reduces the heat exchange capability of vegetable oil and thus yields a high grinding temperature; (6 saturated fatty acid is a more efficient lubricant than unsaturated fatty acid; and (7 a short carbon chain transfers heat more effectively than a long carbon chain. Palm oil is the optimum base oil of MQL grinding, and this base oil yields 26.98 N tangential grinding force, 87.10 N normal grinding force, 119.6 °C grinding temperature, and 42.7% energy

  11. Biomass torrefaction mill

    Science.gov (United States)

    Sprouse, Kenneth M.

    2016-05-17

    A biomass torrefaction system includes a mill which receives a raw biomass feedstock and operates at temperatures above 400 F (204 C) to generate a dusty flue gas which contains a milled biomass product.

  12. Ship Roll Damping Control

    DEFF Research Database (Denmark)

    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...

  13. Innovative grinding wheel design for cost-effective machining of advanced ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Licht, R.H.; Kuo, P.; Liu, S.; Murphy, D.; Picone, J.W.; Ramanath, S.

    2000-05-01

    This Final Report covers the Phase II Innovative Grinding Wheel (IGW) program in which Norton Company successfully developed a novel grinding wheel for cost-effective cylindrical grinding of advanced ceramics. In 1995, Norton Company successfully completed the 16-month Phase I technical effort to define requirements, design, develop, and evaluate a next-generation grinding wheel for cost-effective cylindrical grinding of advanced ceramics using small prototype wheels. The Phase II program was initiated to scale-up the new superabrasive wheel specification to larger diameters, 305-mm to 406-mm, required for most production grinding of cylindrical ceramic parts, and to perform in-house and independent validation grinding tests.

  14. Assessment of heavy metals introduced into food through milling process: health implications

    International Nuclear Information System (INIS)

    The present study was conducted to characterised and assesss heavy metal contamination in food through milling process and their health implications. Grinding plate made from Ghana, India and Nigeria purchased from the Ghanaian open market were used for this work. Maize from the same farm was milled into flour using the three grinding plate inserted into three different corn milling machines operating on commercial bases. Th first grinding was done immediately after the insertion of the newly sharpened plates into the machines. The plates were left for continuous daily usage. Subsequent milling of the maize was done after intervals of one month. The grinding plates and maize flour was analysed using Atomic absorption spectrophometer (AAS). The resultes recorded indicated that the heavy metals content o the Ghanaian, Indian and Nigerian made plates had the e similar metal contents but varied in terms of the individual metal concentrations. Flour from the Ghanaian made plates had the highest level of contaminants with the least from that of the Indian made plates. Generally, the highest levels of contamination were observed in the fist milling for the three plates as compared to the three subsequent milling at monthly interval. The contamination levels showed a decreasing trend from the first month (first milling ) to the fourth month (fourth milling). Cu, Cr and Ni showed concentrations above the permissible limit set by FAO/WHO in milled maize using Ghanaian made plate. Copper (Cu) recorded a concentration value between 15.04 mg/kg to 10.21mg.kg, 11.25 mg/kg to 9.13mg/kg and 10.36mg/kg and 9.68mg/kg using the Ghanaian-, Indian and Nigerian made plate respectively. Chromium (Cr) recorded a concentration between 1.51 mg/kg to 0.96 mg/kg, 1.03mg/kg to 0.91 mg/kg and 0.98mg/kg to 0.80 mg/kg using Ghanaian-, Indian and Nigerian made plates respectively. Nickel (Ni) recorded a concentration value between 23.23 mg/kg to 10.43 mg/kg, 11.46mg/kg to 10.43 mg/kg and 12.55 mg

  15. Gemstone Grinding Process Improvement by using Impedance Force Control

    Directory of Open Access Journals (Sweden)

    Hamprommarat Chumpol

    2015-01-01

    Full Text Available Chula Automatic Faceting Machine has been developed by The Advance Manufacturing Research Lab, Chulalongkorn University to support Thailand Gems-Industry. The machine has high precision motion control by using position and force control. A contact stiffness model is used to estimate grinding force. Although polished gems from the Faceting Machine have uniform size and acceptable shape, the force of the grinding and polishing process cannot be maintain constant and has some fluctuation due to indirect force control. Therefor this research work propose a new controller for this process based on an impedance direct force control to improve the gemstone grinding performance during polishing process. The grinding force can be measured through motor current. The results show that the polished gems by using impedance direct force control can maintain uniform size as well as good shape and high quality surface.

  16. A critical study of high efficiency deep grinding

    CERN Document Server

    Johnstone, I

    2002-01-01

    The recent years, the aerospace industry in particular has embraced and actively pursued the development of stronger high performance materials, namely nickel based superalloys and hardwearing steels. This has resulted in a need for a more efficient method of machining, and this need was answered with the advent of High Efficiency Deep Grinding (HEDG). This relatively new process using Cubic Boron Nitride (CBN) electroplated grinding wheels has been investigated through experimental and theoretical means applied to two widely used materials, M50 bearing steel and IN718 nickel based superalloy. It has been shown that this grinding method using a stiff grinding centre such as the Edgetek 5-axis machine is a viable process. Using a number of experimental designs, produced results which were analysed using a variety of methods including visual assessment, sub-surface microscopy and surface analysis using a Scanning Electron Microscope (SEM), residual stress measurement using X-Ray Diffraction (XRD) techniques, Ba...

  17. Grinding Characteristics of Multi-component Cement-based Material

    Institute of Scientific and Technical Information of China (English)

    LU Difen; TAO Longzhong; LI Ning; HU Haipeng

    2005-01-01

    The grinding characteristics of two or multi-component material of clinker with limestone, blast furnace slag and fly ash were studied. Investigation was carried out on the particle size distribution, the Blaine fineness and the sieve residue of the separate and interground products. The relative contents of clinker and limestone in different size fractions of the interground product were examined, and the interaction of two components, which have different grindabilities, was analyzed. The results show there exists a selective grinding effect during intergrinding, one component can help or hinder the grinding of the other. Making good use of this interaction appropriately not only enhances the grindabilities of two or multi-component mixtures, which can promote the grinding process of clinker with industrial wastes, but also improves their particle size distribution and properties.

  18. E-Records a Grind for Many Doctors

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_160789.html E-Records a Grind for Many Doctors And this ... direct contact with patients and 37 percent on E-health records and other clerical work, the study ...

  19. Experimental Study on Effects of Grinding Way on Grinding Effectiveness with Grinding Head of Polishing Machine%抛光机磨头磨削方式对磨削效果影响的试验研究

    Institute of Scientific and Technical Information of China (English)

    邵俊鹏; 徐斌; 李冲

    2011-01-01

    In order to investigate the grinding effectiveness of different grinding heads, a mathe- matical model of grinding process with vertical spindle grinding head of polishing machine was established. The effectiveness of the model was verified by experiments. According to the results of theoretical analysis and experimental research, it is concluded that tiles are grinded by vertical spindle grinding head of polishing machine and the tile surface is not smooth. Machining way of tilting spindle grinding head grinding tiles was invented. A series of experiments with tilting spindle grinding head grinding tiles were performed, for grinding tiles tilting spindle grinding head with constant depth can improve the tile surface smoothness effectively.%为了研究不同磨头的磨削效果,建立了垂直轴磨头磨削过程模型,并通过试验验证了其正确性。综合理论分析和试验研究结果可知:垂直轴磨头磨削瓷砖时,磨削后的瓷砖表面不平整。提出了倾斜轴磨头磨削瓷砖的加工方式,通过一系列试验得出倾斜轴磨头定深磨削可以有效提高瓷砖的平整度的结论。

  20. Effect of Thermomechanical Processing on Mechanical Properties of Hot Rolled Multiphase Steel

    Institute of Scientific and Technical Information of China (English)

    LI Zhuang; WU Di; L(U) Hui-sheng

    2008-01-01

    The effect of thermomechanical processing (TMP) on the mechanical properties of hot rolled multiphase steel was investigated. TMP was conducted using a laboratory hot rolling mill, in which three different kinds of finish rolling deformation degrees and temperatures were applied. The results indicate that polygonal ferrite, granular bainite, and a considerable amount of stabilized retained austenite can be obtained by TMP. The stability of the retained austenite increases with decreasing finish rolling temperature and increasing finish rolling deformation degrees. Ultimate tensile strength (σb), total elongation (δ), and the product of ultimate tensile strength by total elongation (σb·δ) for 50% reduction at finish rolling temperature of 700 ℃ reach maximum values [791 MPa, 36% and 28 476 (MPa·%), respectively].

  1. Improving the Surface Roughness of Pickled Steel Strip by Control of Rolling Temperature

    Science.gov (United States)

    Chang, Yao-Nan; Lin, Szu-Ning; Liou, Horng-Yih; Chang, Chu-Wei; Wu, Chia-Chan; Wang, Ying-Chun

    2013-01-01

    This investigation is to analyze the surface roughness problem of low carbon pickled steel strips from the view points of prior hot rolling conditions and the hot-rolled scales. The results showed that, compared with other parameters, the most important factor in hot rolling to affect the surface roughness was the rolling temperature. As the temperature was increased, the amount of the outer brittle α-Fe2O3 increased, leading to rough scale/substrate interface and rough surface after pickling. However, the effect of coiling temperature was almost negligible because no further rolling existed after that stage. Quantitative estimation showed that decrease in rolling temperature in this investigation reduced the surface roughness, Ra, from 1.06-1.78 μm to 0.88-1.10 μm after pickling in laboratory. Similar degree of improvement in roughness was also observed after pickling in mill.

  2. Recent developments in modeling of hot rolling processes: Part I - Fundamentals

    Science.gov (United States)

    Hirt, Gerhard; Bambach, Markus; Seuren, Simon; Henke, Thomas; Lohmar, Johannes

    2013-05-01

    The numerical simulation of industrial rolling processes has gained substantial relevance over the past decades. A large variety of models have been put forward to simulate single and multiple rolling passes taking various interactions between the process, the microstructure evolution and the rolling mill into account. On the one hand, these include sophisticated approaches which couple models on all scales from the product's microstructure level up to the elastic behavior of the roll stand. On the other hand, simplified but fast models are used for on-line process control and automatic pass schedule optimization. This publication gives a short overview of the fundamental equations used in modeling of hot rolling of metals. Part II of this paper will present selected applications of hot rolling simulations.

  3. Teeth Grinding: Is Emotional Stability related to Bruxism?

    OpenAIRE

    Sutin, Angelina R.; Terracciano, Antonio; Ferrucci, Luigi; Costa, Paul T.

    2010-01-01

    This study examines the association between personality traits and bruxism, the repetitive grinding or clenching of teeth. Community-dwelling participants (N = 470) had a comprehensive oral examination by a dentist and completed a dental history and personality questionnaires. Consistent with the literature on state anxiety and depression as antecedents of bruxism, Neuroticism-related traits were associated with self-reported teeth grinding. These traits were also associated with other oral c...

  4. A critical study of high efficiency deep grinding

    Energy Technology Data Exchange (ETDEWEB)

    Johnstone, Iain

    2002-07-01

    The recent years, the aerospace industry in particular has embraced and actively pursued the development of stronger high performance materials, namely nickel based superalloys and hardwearing steels. This has resulted in a need for a more efficient method of machining, and this need was answered with the advent of High Efficiency Deep Grinding (HEDG). This relatively new process using Cubic Boron Nitride (CBN) electroplated grinding wheels has been investigated through experimental and theoretical means applied to two widely used materials, M50 bearing steel and IN718 nickel based superalloy. It has been shown that this grinding method using a stiff grinding centre such as the Edgetek 5-axis machine is a viable process. Using a number of experimental designs, produced results which were analysed using a variety of methods including visual assessment, sub-surface microscopy and surface analysis using a Scanning Electron Microscope (SEM), residual stress measurement using X-Ray Diffraction (XRD) techniques, Barkhausen Noise Amplitude (BNA) measurements, surface roughness and Vickers micro-hardness appraisal. It has been shown that the fundamentals of the HEDG process have been understood through experimental as well as theoretical means and that through the various thermal models used, grinding temperatures can be predicted to give more control over this dynamic process. The main contributions to knowledge are made up of a number of elements within the grinding environment, the most important being the demonstration of the HEDG effect, explanation of the phenomenon and the ability to model the process. It has also been shown that grinding is a dynamic process and factors such as wheel wear will result in a continuous change in the optimum grinding conditions for a given material and wheel combination. With the significance of these factors recognised, they can be accounted for within an industrial adaptive control scenario with the process engineer confident of a

  5. Dry-grinded ultrafine cements hydration. physicochemical and microstructural characterization

    OpenAIRE

    Foteini Kontoleontos; Petros Tsakiridis; Apostolos Marinos; Nikolaos Katsiotis; Vasileios Kaloidas; Margarita Katsioti

    2013-01-01

    The aim of the present research work was the evaluation of the physicochemical and microstructural properties of two ultrafine cements, produced by dry grinding of a commercial CEM I 42.5N cement. The effect of grinding on particle size distribution was determined by laser scattering analyzer. All cements were tested for initial and final setting times, consistency of standard paste, soundness, flow of normal mortar and compressive strengths after 1, 2, 7 and 28 days. The effect of the finene...

  6. A Path Planning Method for Robotic Belt Surface Grinding

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; YUN Chao

    2011-01-01

    The flexible contact and machining with wide strip are two prominent advantages for the robotic belt grinding system,which can be widely used to improve the surface quality and machining efficiency while finishing the workpieces with sculptured surfaces.There lacks research on grinding path planning with the constraint of curvature.With complicated contact between the contact wheel and the workpiece,the grinding paths for robot can be obtained by the theory of contact kinematics.The grinding process must satisfy the universal demands of the belt grinding technologies,and the most important thing is to make the contact wheel conform to the local geometrical features on the contact area.For the local surfaces with small curvature,the curve length between the neighboring cutting locations becomes longer to ensure processing efficiency.Otherwise,for the local areas with large curvature,the curve length becomes shorter to ensure machining accuracy.A series of planes are created to intersect with the target surface to be ground,and the corresponding sectional profile curves are obtained.For each curve,the curve length between the neighboring cutting points is optimized by inserting a cutter location at the local area with large curvatures.A method of generating the grinding paths including curve length spacing optimization is set up.The validity is completely approved by the off-line simulation,and during the grinding experiments with the method,the quality of surface is improved.The path planning method provides a theoretical support for the smooth and accuracy path of robotic surface grinding.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    International Nuclear Information System (INIS)

    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

  9. CISM Course on Rolling Contact Phenomena

    CERN Document Server

    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

  10. Dynamics and Control of Grinding Machine with Micropositioning Workpiece Table

    Institute of Scientific and Technical Information of China (English)

    TIAN Yanling; ZHANG Dawei; YAN Bing

    2006-01-01

    To improve the machining precision of a surface grinding machine, a micropositioning workpiece table with high performance was used as auxiliary infeed mechanism to implement nanometer level positioning and dynamic compensation.To better understand the characteristics of the grinding machine modulated with micropositioning workpiece table, the dynamic model of the grinding system was established with modal synthesis and Lagrange's equation methods.The grinding system was divided into five subsystems.For each subsystem, the generalized kinematic and potential energies were obtained.Accordingly the dynamic model of the grinding system was given in the modal domain.The waviness of the grinding process was achieved based on the wheel and workpiece vibration.A nonlinear proportional integral derivative (PID) controller with differential trackers was developed to realize dynamic control.The simulation results show that the machining accuracy of the workpiece can be effectively improved by utilizing the micropositioning workpiece table to implement dynamic compensation.An experimental test was carried out to verify the proposed method, and the waviness of the workpiece can be reduced from 0.46 μm to 0.10 μm.

  11. Grinding aspheric and freeform micro-optical molds

    Science.gov (United States)

    Tohme, Yazid E.

    2007-02-01

    Fueled by the need for better performing optics, glass optics are now replacing plastic optics in many industrial and consumer electronic devices. One of these devices is the mobile phone camera. The optical sub-assembly in a mobile phone includes several micro lenses that are spherical and/or aspherical in shape and require form tolerances in the submicron range. These micro glass lenses are mass produced by a replication process known as glass press molding. The process entails the compression of a glass gob between two precise optical quality molds at an elevated temperature, usually near the transition temperature of the glass material. The elevated forces and temperatures required in the glass molding process limits the materials of the molds to very tough materials such as tungsten carbide or silicon carbide. These materials can withstand large pressing forces at high temperatures without any significant deformation. These materials offer great mechanical properties for glass press molding but they are also a challenge to machine to submicron accuracy. The work in this paper discusses a deterministic micro grinding manufacturing process referred to as wheel normal grinding, which is utilized to produce these optical quality molds. Wheel normal grinding is more accurate and more deterministic than most other grinding techniques and can produce molds to the form and finish tolerances required for optical molding. This method relies on the ability to recognize and compensate for grinding wheel wear and machine repeatable errors. Results will be presented to illustrate the accuracy of this micro grinding technique.

  12. Noise emission of concrete pavement surfaces produced by diamond grinding

    Directory of Open Access Journals (Sweden)

    Jens Skarabis

    2015-04-01

    Full Text Available In Germany, diamond grinding is frequently used to improve the evenness and skid resistance of concrete pavement surfaces. Since diamond grinding has been observed to affect tyre/pavement noise emission favourably, the relationship among surface texture, concrete composition and noise emission of concrete pavement surfaces has been systematically investigated. The simulation program SPERoN was used in a parameter study to investigate the main factors which affect noise emission. Based on the results of the simulations, textured concrete surfaces were produced by using a laboratory grinding machine. As well as the composition of the concrete, the thickness and spacing of the diamond blades were varied. The ability of the textured surfaces to reduce noise emission was assessed from the texture characteristics and air flow resistance of textured surfaces measured in the laboratory. It was found that concrete composition and, in particular, the spacing of the blades affected the reduction in noise emission considerably. The noise emission behaviour of numerous road sections was also considered in field investigations. The pavement surfaces had been textured by diamond grinding during the last years or decades. The results show that diamond grinding is able to provide good, durable noise-reducing properties. Several new pavement sections were investigated using thicknesses and spacings of the blades similar to those used in the laboratory to optimize noise emission reduction. It is concluded that diamond grinding is a good alternative to exposed aggregate concrete for the production of low-noise pavement surfaces.

  13. The Design of Form Milling Cutter as the Curve of the Back of Tooth Is Logarithmic Spiral

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Form milling cutter is built-for-purpose cutter which process the form surface, for example, usually process male and female circular arc face and form trench and so on. From the traditional concept, form milling cutter is divided into pointed tooth and relieving follow its structure. Relieving shaped cutter is more convenient than pointed tooth milling cutter, because only its rake face is needed to grind after it turn into blunting, so the current books which are used in college almost select relieving ...

  14. Skin pass mill tension leveling facility for stainless steel sheets; Stainless kobanyo sukinpasumiru tension leveling setsubi

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-04-20

    This facility was delivered to Acerinox S.A. (Spain) for surface property improvement, mechanical property improvement and shape correction of bright annealed materials in the end facility of No.3 BAL. Main specifications: (1) Material to be handled: stainless steel sheet (bright annealed cold-rolled steel sheet), (2) Sheet thickness and width: 0.15-2.0mm x 600-1,300mm, (3) Processing speed: 90m/min maximum, (4) Rolling mill: 4 Hi hydraulic depression system, (5) Tension leveler: 6 Hi wet system. Features: (1) Some degree of a flatness only by a skin pass mill through automatic flatness control by work roll bender, 4 Hi skin pass mill with a variable crown backup roll, and shape meter, (2) Stable dead flatness of 0.1% in elongation rate by adding a tension leveler, (3) High-quality bright annealing without any pressed flaw and roll mark by applying an advanced wiper to a skin pass mill, and applying switching control during traveling of welding points to wet leveling and skin pass leveler rolling. (translated by NEDO)

  15. Research on strip hysteretic behavior and mill vertical vibration system nonlinear dynamics

    Science.gov (United States)

    Fan, Xiaobin; Zang, Yong; Jin, Ke

    2016-10-01

    Rolling mill vibration is a technical problem in the iron and steel industry for many years and has serious impact and harm on production. There were serious vibrations in the middle mills when rolling thin container strip for the compact strip production (CSP) strip hot rolling process. This paper studied the hysteretic characteristic of rolled strip and established the vertical vibration system single-degree-of-freedom dynamics model of the F3 mill rollers. The influence of parameters on the system characteristics was studied, such as the linear damping coefficient, linear stiffness coefficient, nonlinear displacement coefficient, nonlinear velocity coefficient and exciting force, and then, the vibration source and vibration-restraining measure were studied from the roll gap. The results show that with increasing linear stiffness, damping and hysteresis coefficient, it can reduce the possibility of chaotic system; the linear stiffness coefficient had the greatest influence, and hysteresis damping coefficient had minimal influence on chaotic threshold. In order to reduce rolling mill vibration amplitude, we should reduce the external excitation force firstly, and in order to improve the dynamic performance of the system, we should control the speed of nonlinear coefficient values. The contrast experiments were carried out at the production scene finally.

  16. Ball-milled sulfur-doped graphene materials contain metallic impurities originating from ball-milling apparatus: their influence on the catalytic properties.

    Science.gov (United States)

    Chua, Chun Kiang; Sofer, Zdeněk; Khezri, Bahareh; Webster, Richard D; Pumera, Martin

    2016-07-21

    Graphene materials have found applications in a wide range of devices over the past decade. In order to meet the demand for graphene materials, various synthesis methods are constantly being improved or invented. Ball-milling of graphite to obtain graphene materials is one of the many versatile methods to easily obtain bulk quantities. In this work, we show that the graphene materials produced by ball-milling are spontaneously contaminated with metallic impurities originating from the grinding bowls and balls. Ball-milled sulfur-doped graphene materials obtained from two types of ball-milling apparatus, specifically made up of stainless steel and zirconium dioxide, were investigated. Zirconium dioxide-based ball-milled sulfur-doped graphene materials contain a drastically lower amount of metallic impurities than stainless steel-based ball-milled sulfur-doped graphene materials. The presence of metallic impurities is demonstrated by their catalytic effects toward the electrochemical catalysis of hydrazine and cumene hydroperoxide. The general impression toward ball-milling of graphite as a versatile method for the bulk production of 'metal-free' graphene materials without the need for post-processing and the selection of ball-milling tools should be cautioned. These findings would have wide-reaching implications for graphene research.

  17. Ball-milled sulfur-doped graphene materials contain metallic impurities originating from ball-milling apparatus: their influence on the catalytic properties.

    Science.gov (United States)

    Chua, Chun Kiang; Sofer, Zdeněk; Khezri, Bahareh; Webster, Richard D; Pumera, Martin

    2016-07-21

    Graphene materials have found applications in a wide range of devices over the past decade. In order to meet the demand for graphene materials, various synthesis methods are constantly being improved or invented. Ball-milling of graphite to obtain graphene materials is one of the many versatile methods to easily obtain bulk quantities. In this work, we show that the graphene materials produced by ball-milling are spontaneously contaminated with metallic impurities originating from the grinding bowls and balls. Ball-milled sulfur-doped graphene materials obtained from two types of ball-milling apparatus, specifically made up of stainless steel and zirconium dioxide, were investigated. Zirconium dioxide-based ball-milled sulfur-doped graphene materials contain a drastically lower amount of metallic impurities than stainless steel-based ball-milled sulfur-doped graphene materials. The presence of metallic impurities is demonstrated by their catalytic effects toward the electrochemical catalysis of hydrazine and cumene hydroperoxide. The general impression toward ball-milling of graphite as a versatile method for the bulk production of 'metal-free' graphene materials without the need for post-processing and the selection of ball-milling tools should be cautioned. These findings would have wide-reaching implications for graphene research. PMID:27314607

  18. 磨矿方法对某硫化矿浮选的影响%Effects of Grinding Measure on Complex Pb/Zn Ore Flotation

    Institute of Scientific and Technical Information of China (English)

    魏以和; 周高云

    2007-01-01

    The flotation performances of a complex Pb/zn ore are investigated by three kinds of mill(steel,stainless and ceramic mill)in laboratory batch flotation testa.It is found that the lead recovery is increased while grinding in a ceramic mill,i.e.a non-ferrous,oxidizing environment.but the selectivity is decreased due to the activation ol sphalerite by copper ions produced via the oxidation of ore.On the contrary,the lead recovery is decreased while grinding in a traditionel iron mill,but the selectivity is increased.The low recovery with iron grinding media is probably caused by the coating of iron oxy-hydroxides on sulphide surfaces.Coarse particles are more sensitive to this kind of depression.%为提高效果,用三种磨机(普通钢磨机,不锈钢磨机和瓷磨机)研究某铅锌矿小型试验的浮选行为.结果表明,瓷磨机(即非铁质磨机)的氧化性磨矿环境可提高铅回收率,但由于矿石氧化产生的铜离子对闪锌矿的活化而降低了浮选选择性.相反地,传统铁质磨机磨矿则导致铅收率下降,而选择性提高.铁质磨机磨矿时铅收率降低可能是由铁氧化产物在矿物表面覆盖而造成的.粗粒更易受这种抑制的影响.

  19. Design of Ultra-Precision CNC Grinding Machine and Its Application in Machining Large Aspheric Mirrors

    Institute of Scientific and Technical Information of China (English)

    Bin Li; Huiying Zhao; Jianpu Xi; Dongxu Ren

    2015-01-01

    Large aspheric mirrors are needed for the remote sensing and ground based telescope optical systems, these mirrors are made of hard and brittle materials which require ultra⁃precision grinding process to guarantee the high profile accuracy and machining efficiency. The ultra⁃precision aspheric CNC grinding machine (UAG900) is presented by this paper, as well as its grinding capability. The hydrostatic bearings of high accuracy and stiffness are adopted by the linear and rotary motions to guarantee the mirror accuracy, material removal rate and subsurface damage. Disk type grinding wheel with arc edge is used. The material removal rate can be up to 360 mm3/min to guarantee the machining efficiency during rough grinding using D180 diamond grinding wheel while the fine grinding is performed using D15 grinding wheel. It indicates that the grinding wheel radius measuring error is proportional to the profile error induced by the grinding path. The grinding step size is better to be 0�01 mm for the reduction of the grinding movement accelerations and program length. The grinding path is planned and expressed based on the grinding mode according to the mirror shape. One 540 mm×450 mm×100 mm zerodur mirror is ground and re⁃ground using the measuring data acquired by the Leitz CMM. The final surface accuracy of P⁃V value is less than 5 μm after compensation grinding.

  20. Quantum dice rolling

    CERN Document Server

    Aharon, N

    2009-01-01

    A coin is just a two sided dice. Recently, Mochon proved that quantum weak coin flipping with an arbitrarily small bias is possible. However, the use of quantum resources to allow N remote distrustful parties to roll an N-sided dice has yet to be addressed. In this paper we show that contrary to the classical case, N-sided dice rolling with arbitrarily small bias is possible for any N. In addition, we present a six-round three-sided dice rolling protocol, achieving a bias of 0.181, which incorporates weak imbalanced coin flipping.

  1. Coiling Temperature Control in Hot Strip Mill

    Science.gov (United States)

    Imanari, Hiroyuki; Fujiyama, Hiroaki

    Coiling temperature is one of the most significant factors in products of hot strip mill to determine material properties such as strength, toughness of steel, so it is very important to achieve accurate coiling temperature control (CTC). Usually there are a few pyrometers on the run out table in hot strip mill, therefore temperature model and its adapting system have large influences on the accuracy of CTC. Also unscheduled change of rolling speed has a bad effect to keep coiling temperature as its target. Newly developed CTC system is able to get very accurate coiling temperature against uncertain factors and disturbances by adopting easily identified temperature model, learning method and dynamic set up function. The features of the CTC system are discussed with actual data, and the effectiveness of the system is shown by actual control results.

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

    Science.gov (United States)

    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

  3. The use of Bayesian Networks in Detecting the States of Ventilation Mills in Power Plants

    Directory of Open Access Journals (Sweden)

    Sanja Vujnović

    2014-06-01

    Full Text Available The main objective of this paper is to present a new method of predictive maintenance which can detect the states of coal grinding mills in thermal power plants using Bayesian networks. Several possible structures of Bayesian networks are proposed for solving this problem and one of them is implemented and tested on an actual system. This method uses acoustic signals and statistical signal pre-processing tools to compute the inputs of the Bayesian network. After that the network is trained and tested using signals measured in the vicinity of the mill in the period of 2 months. The goal of this algorithm is to increase the efficiency of the coal grinding process and reduce the maintenance cost by eliminating the unnecessary maintenance checks of the system.

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

    Institute of Scientific and Technical Information of China (English)

    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.

  5. Grooved roll for a high speed twin roll caster

    Directory of Open Access Journals (Sweden)

    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.

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

    OpenAIRE

    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...

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

    Institute of Scientific and Technical Information of China (English)

    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.

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

    OpenAIRE

    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 ...

  9. Rolled-Up Metamaterials

    Directory of Open Access Journals (Sweden)

    Stephan Schwaiger

    2012-01-01

    Full Text Available In this paper we review metamaterials fabricated from self-rolling strained metal-semiconductor layer systems. These systems relax their strain upon release from the substrate by rolling up into microtubes with a cross-section similar to a rolled-up carpet. We show that the walls of these microtubes represent three-dimensional optical metamaterials which so far could be used, for example, for the realization of broadband hyperlenses, fishnet metamaterials, or optically active three-dimensional metamaterials utilizing the unique possibility to stack optically active semiconductor heterostructures and metallic nanostructures. Furthermore, we discuss THz metamaterials based on arrays of rolled-up metal semiconductor microtubes and helices.

  10. Rolling element fatigue testing of gear materials

    Science.gov (United States)

    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. Effect of Milling Time on Al-Fe-Cr-20 Wt. % Al2O3composite Prepared Through Ball Milling

    Directory of Open Access Journals (Sweden)

    Hameedur Rehman Khan

    2014-07-01

    Full Text Available One of the main challenges towards achieving a homogeneous distribution of the ceramic phase in the metal matrix composites is agglomeration of the reinforcement particles. Mechanical alloying is among the most important processing techniques used for manufacturing of metal matrix composites (MMCs.An attempt was made to synthesize Al-Fe-Cr-Al2O3composites synthesized through mechanical alloying. Al2O3 is used as reinforcement. Ethanol (5 wt. % has been used as a process control agent (PCA. Mechanical alloying is carried out in a conventional ball mill using stainless steel grinding media at 115 rpm in the argon environment for 5h, 10h and 15h. The ball to powder weight ratio was maintained at 20:1. The characterization of the ball milled powder was followed by scanning electron microscopy (SEM. Showed the formation of a homogeneous phase for all compositions after milling for 15 h. XRD patterns were recorded for the milled powders, and analyzed using Williamson–Hall method and Scherrer’s equation to determine the lattice strain and grain size.EDX is performed to check the contamination of composites during the mechanical alloying.XRD is used to study structural evolution of synthesized aluminium composite. Effect of milling time is investigated on synthesized Al-Fe-Cr-20 wt. % Al2O3 composites.

  12. Quenching simulation of steel grinding balls

    Directory of Open Access Journals (Sweden)

    Zapata-Hernández, Oscar

    2015-09-01

    Full Text Available The phase transformations of high carbon steel during quenching and equalizing were modelled using commercial computer packages based on the finite element method and the kinetic transformation of steel. The model was used to predict the temperature and microstructural changes taking place within balls of two different sizes that are used for grinding mineral ores. A good correlation between the temperatures measured by inserted thermocouples and those predicted by the model was obtained after modifying the thermal conductivity of the steel within the temperature domain at which mixed phases are present. The phase transformations predicted were confirmed by metallographic analyses.Las transformaciones de fase en aceros de alto carbono durante su temple y un posterior periodo de estabilización fueron modelizadas por medio del uso de paquetes computacionales basados en el método del elemento finito y de la transformación cinética de los aceros. El modelo se usó para predecir los cambios de temperatura y microestructura que se presentan en bolas de dos diferentes tamaños empleadas en estaciones de molienda de minerales. Se encontró una buena correlación entre las temperaturas medidas mediante la inserción de termopares y aquellas predichas por el modelo una vez que se modificó la conductividad térmica del acero en el intervalo mixto de fases. La predicción de las transformaciones de fase se confirmó a través del análisis metalográfico.

  13. Performance of Cooled Cone Grinding Machine in Cocoa Cake Processing

    Directory of Open Access Journals (Sweden)

    Hendy Firmanto

    2015-08-01

    Full Text Available The process of cocoa paste pressing has a function to separate the fatty component of cocoa from its cake. Cocoa paste is further processed into cocoa powder using grinding machine for cocoa cake. The cooled cone type of cocoa grinding machine is used to solve the problem of plug in the maschine caused by melting of fat in cocoa cake due to hot effect as a result of friction in the grinding machine. Grinding machine of cocoa has conical form of cylinder for grinding and stator wall wrapped by source of cold and closed with jacket wool. Research was conducted at Kaliwining Experimental Garden of Indonesian Coffee and Cocoa Research Institute (ICCRI using cocoa cake containing 26.75% originated from Forastero type of cocoa seed. The capacity and recovery of the machine was influenced by space between rotor cylinder and stator wall. Grinding machine operated at cooling temperature of 25.5oC and space between rotor – stator 0.9 cm and the capacity of 187.5 kg/hour with recovery of 200 mesh cocoa powder as much as 24%. The maximum  power of machine required  was 2.5 kW with efficiency of  energy transfer of 97%. Results of proximate analysis showed that there was no change of protein content, but protein and carbohydrate content increased after processing, i.e. from 5.70% and 59.82% into 5.80% and 61.89% respectively.Key words : cocoa cake, cooling, grinding, cocoa powder 

  14. Identification and control of grinding processes for intermetallic compounds

    Science.gov (United States)

    Razavi, Hosein Ali

    2000-10-01

    An intermetallic compound (IMC) is a combination of two or more metals with a particular atomic formula by having either ionic and covalent bonds, or metallic bonds with specific crystal structures. They may be thought of as the intermediate between metals and ceramics. These new materials may combine the best of each class: the ductility, heat and electric conductivity of metals with the strength and oxidation resistance of ceramics. Previous study has proposed that the depth of plastic deformation can be used as a parameter to describe the influence of grinding conditions on other physical properties of subsurface layers. Accordingly, the indentation model has been developed to correlate the depth of plastic deformation with the normal component of grinding force. It has been reported that the under certain grinding conditions the depth of plastic deformation does not follow the indentation model. The primary objective of this research is to explain such deviations and to demonstrate that this model can be used to control and predict the depth of plastic deformation. Elements of this research include the development of an open architecture platform to study grinding process, a signal processing algorithm for gap elimination, introducing and implementation of model reference unfalsification and learning concept, development of a mathematical model for grinding gamma-TiAl, a comparison between conventional and superabrasive grinding, control and prediction of the depth of plastic deformation, and initiation of one of the first databases for grinding gamma-TiAl. This work not only serves as a step toward the use of IMCs in future technology but also serves as a step toward autonomous machining systems using intelligent control and advanced monitoring which is a feature of the future abrasive technology.

  15. Research on Stability Prediction of the Crankshaft CNC Tangential Point Tracing Grinding

    Directory of Open Access Journals (Sweden)

    Zhuoda Jiang

    2015-01-01

    Full Text Available As the key part of internal combustion engines, crankshaft with high efficiency and accuracy processing has always been the target of the engine manufacturer’s pursuit. Grinding is used to obtain the ultimate dimensional accuracy and surface finish in the crankshaft machining. Grinding of the main journals and the pin journals can be accomplished in a single clamping operation by CNC Tangential Point Tracing grinding technology. However, the chatter in the grinding process is harmful to the precision and surface quality. In this paper, stability lobe diagram is developed to predict the grinding chatter. First the dynamic model of Tangential Point Tracing grinding system is established. Then the limit formula of the critical grinding depth is calculated and the stability lobe diagram of the grinding system is presented. Finally, the validation experiments are carried out on the crankshaft grinding machine and the results are consistent with the calculation.

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

    International Nuclear Information System (INIS)

    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

  17. Flow Stress Evaluation in Hot Rolling of Steel

    Science.gov (United States)

    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.

  18. Austempering of hot rolled transformation-induced plasticity steels

    Institute of Scientific and Technical Information of China (English)

    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.

  19. Size-reduction and sorting behavior in sieve hammer mills

    Science.gov (United States)

    Schallnus, Harald

    Experiments were performed in a continuously operating sieve hammer mill to determine the duration of presence of the material to be ground in the size reduction machine. The test stand, analysis techniques, evaluation methods, and selection and production of samples are described. It is shown that the duration of presence of the material in the grinding space of the mill is approximately comparable to that in an ideal mixer. The type of sieve casing has an essential effect on the duration of presence. A combined model for the description of the size reduction and sorting behavior which allows the determination of the process coefficients (size reduction speed, sorting speed, mass transition coefficient) and their dependence on the different parameters, was developed.

  20. Advanced Modeling and Materials in Kraft Pulp Mills

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, J.R.; Gorog, J.P.

    2002-05-15

    This CRADA provided technical support to the Weyerhaeuser Company on a number of issues related to the performance and/or selection of materials at a number of locations in a pulp and paper mill. The studies related primarily to components for black liquor recovery boilers, but some effort was directed toward black liquor gasifiers and rolls for paper machines. The purpose of this CRADA was to assist Weyerhaeuser in the evaluation of materials exposed in various paper mill environments and to provide direction in the selection of alternate materials, when appropriate.

  1. Global coupled equations for dynamic analysis of planishing mill

    Institute of Scientific and Technical Information of China (English)

    蔡敢为; 钟掘

    2003-01-01

    The dynamic properties of rolling mill are significantly influenced by many coupling factors. Accordingto the coupled mechanical and electric dynamics theory, the global coupled equations for the dynamic analysis ofplanishing mill CM04 of Shanghai Baosteel Group Corporation were derived, by using finite element methods. Theseelasto-dynamic equations establish the coupling relations among the stand vibration system, torsional vibration sys-tem, driving motors, etc. It provides theoretical basis to a certain extent for globally dynamic simulation, analysis ofstability of motion, prediction of abnormal operating mode, globally optimum design and control, etc.

  2. Microstructural Characterization of Calcite-Based Powder Materials Prepared by Planetary Ball Milling

    Directory of Open Access Journals (Sweden)

    Wen-Tien Tsai

    2013-08-01

    Full Text Available In this work, a planetary ball milling was used to modify the surface properties of calcite-based material from waste oyster shell under the rotational speed of 200–600 rpm, grinding time of 5–180 min and sample mass of 1–10 g. The milling significantly changed the microstructural properties of the calcite-based minerals (i.e., surface area, pore volume, true density, and porosity. The surface characterization of the resulting powder should be macroporous and/or nonporous based on the nitrogen adsorption/desorption isotherms. Under the optimal conditions at the rotational speed of 400 rpm, grinding time of 30 min and sample mass of 5 g, the resulting calcite-based powder had larger specific surface area (i.e., 10.64 m2·g−1 than the starting material (i.e., 4.05 m2·g−1. This finding was also consistent with the measurement of laser-diffraction (i.e., 9.7 vs. 15.0 μm of mean diameter. In addition, the results from the scanning electron microscope (SEM observation indicated that surface roughness can be enhanced as particle size decreases as a result of particle-particle attrition. Thus, grinding the aquacultural bioresource by a high-energy ball milling can create the fine materials, which may be applied in the fields of inorganic minerals like aggregate and construction material.

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

    OpenAIRE

    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...

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

    Institute of Scientific and Technical Information of China (English)

    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.

  5. Ductile streaks in precision grinding of hard and brittle materials

    Indian Academy of Sciences (India)

    V C Venkatesh; S Izman; S Sharif; T T Mon; M Konneh

    2003-10-01

    Ductile streaks produced during diamond grinding of hard and brittle materials have aided the subsequent process of polishing. Two novel techniques were used to study the formation of ductile mode streaks during diamond grinding (primary process) of germanium, silicon, and glass. In the first technique, aspheric surfaces were generated on Ge and Si at conventional speeds (5000 rpm). In the second technique, diamond grinding of plano surfaces on glass and Si surfaces using high speed (100,000 rpm) was carried out. Form accuracy, surface finish and ductile mode grinding streaks are discussed in this paper. It was found that resinoid diamond wheels gave more ductile streaks than metal-bonded wheels but better form accuracy was obtained with the latter. Ductile streaks were obtained more easily with pyrex rather than with BK 7 glass thus necessitating very little time for polishing. Ductile streaks appeared in abundance on germanium rather than silicon. Both the novel grinding techniques were used on CNC machining centres.

  6. FM Interviews: Stephanie Mills

    OpenAIRE

    Valauskas, Edward

    2002-01-01

    Stephanie Mills is an author, editor, lecturer and ecological activist who has concerned herself with the fate of the earth and humanity since 1969, when her commencement address at Mills College in Oakland, Calif., drew the attention of a nation. Her speech, which the New York Times called "perhaps the most anguished statement" of the year's crop of valedictory speeches, predicted a bleak future. According to Mills, humanity was destined for suicide, the result of overpopulation and overuse ...

  7. Development of a grinding-specific performance test set-up

    DEFF Research Database (Denmark)

    Olesen, C. G.; Larsen, B. H.; Andresen, E. L.;

    2015-01-01

    The aim of this study was to develop a performance test set-up for America's Cup grinders. The test set-up had to mimic the on-boat grinding activity and be capable of collecting data for analysis and evaluation of grinding performance. This study included a literature-based analysis of grinding...... and an exponentially rising resistance. A custom-made grinding ergometer was developed with computer-controlled resistance and capable of collecting data during the test. The data collected can be used to find measures of grinding performance such as peak power, time to complete and the decline in repeated grinding...... performance....

  8. Establishment of mathematical moment model in twin casting rolling rolls

    Institute of Scientific and Technical Information of China (English)

    孙斌煜; 苑世剑; 张洪; 杜艳平; 张芳萍

    2002-01-01

    In continuous casting rolling process, the deformed body is different from the hot rolling strip. The metal in casting rolling zone is first assumed to be viscous fluid and the mathematical model of casting rolling force is established, then the calculating formula for casting rolling torque is derived. In addition, considering the effects of deforming cone and appendant torque of rotary junctions sealing ring, the calculating model which accords with casting rolling condition is found out. Theoretical formula is proved by experiment.

  9. Spray Rolling Aluminum Strip

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Use of in-process EDM truing to generate complex contours on metal-bond, superabrasive grinding wheels for precision grinding structural ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Piscotty, M. A., LLNL

    1997-08-01

    This paper presents recent work performed at Lawrence Livermore National Laboratory to develop cost-effective, versatile and robust manufacturing methods for grinding precision features in structural ceramics using metal-bond, superabrasive grinding wheels. The developed processes include utilizing specialized, on-machine hardware to generate precision profiles onto grinding wheels using electrical-discharge machining (EDM) and a contoured rotating electrode. The production grinding processes are described, which were developed and used to grind various precision details into a host of structural ceramics such as Al{sub 2}O{sub 3}, Si{sub 3}N{sub 4}, and BeO. The methodologies, hardware and results of both creep-feed and cylindrical grinding are described. A discussion of imparted grinding damage and wheel wear is also presented.

  11. Micro-Plasto-Hydrodynamic Lubrication a Fundamental Mechanism in Cold Rolling

    DEFF Research Database (Denmark)

    Laugier, Maxime; Boman, Romain; Legrand, Nicolas;

    2014-01-01

    This paper presents recent investigations in Micro-Plasto-Hydrodynamic (MPH) lubrication. Industrial evidences of the existence of MPH lubrication mechanism for cold rolling processes are presented. A new lubrication model developed for strip drawing processes is then applied to predict the MPH...... lubrication initiation and MPH lubrication extension along the tool-piece solid contacts initially in boundary lubrication regime. Finally, it is shown how this new MPH lubrication model can be implemented in a cold rolling model to maximize mills capabilities, determine optimum rolling oils properties...

  12. 磨料有序化排布砂轮磨削 TC4温度实验研究%Experimental investigation of grinding temperature when grinding TC4 with engineered grinding wheels

    Institute of Scientific and Technical Information of China (English)

    陈晨; 王军; 吕玉山; 刘兆博; 王新争

    2015-01-01

    In order to achieve the variation of grinding temperature during grinding TC4 with engineered grinding wheels . Phyllotactic , staggered and random arrangement way of electroplating CBN grinding wheels was used for grinding TC4 .Through the grinding experiment , the relationships of the feed velocity and grinding depth on the workpiece surface temperature and the comparison of grinding temperature with three kinds of engineered grinding wheels were studied . The test results revealed that the TC4 grinding temperature with engineered grinding wheels could be effectively reduced at the same grinding conditions , and lower surface temperature could be obtained with phyllotactic grinding wheel .%为了获得磨料有序化排布砂轮磨削 TC4的温度变化规律,使用电镀 CBN 砂轮对 TC4合金进行磨削实验。砂轮分别采用叶序、错位和无序3种不同的磨料排布方式。研究了工件表面平均温度与进给速度和磨削深度的关系,并对3种磨料排布方式的电镀 CBN 砂轮磨削工件时温度的变化形态进行对比。结果表明:在相同磨削条件下,磨料有序化排布能有效降低 TC4的磨削温度,使用叶序排布磨料砂轮能获得更低的工件表面温度。

  13. Effect of pass schedule and groove design on the metal deformation of 38MnVS6 in the initial passes of hot rolling

    Indian Academy of Sciences (India)

    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.

  14. Design and experimental study of a micro-groove grinding wheel with spray cooling effect

    Directory of Open Access Journals (Sweden)

    Shi Chaofeng

    2014-04-01

    Full Text Available The effectiveness of grinding fluid supply has a crucial impact on grinding quality and efficiency in high speed grinding. In order to improve the cooling and lubrication, through in-depth research of self-inhaling internal cooling method and intermittent grinding mechanism, a new spray cooling method used in high speed grinding is proposed. By referring to the structure of bowl-shaped dispersion disk, the grinding wheel matrix with atomization ability is designed; through studying heat transfer of droplet collision and the influence of micro-groove on the boiling heat transfer, grinding segment with micro-groove is designed to enhance the heat flux of coolant and achieve maximum heat transfer between droplets and grinding contact zone. High-speed grinding experiments on GH4169 with the developed grinding wheel are carried out. The results show that with the micro-groove grinding wheel just 5.4% of pump outlet flow rate and 0.5% of spindle energy is needed to reduce the grinding temperature to 200 °C, which means the developed grinding wheel makes cooling high efficient and low energy consuming.

  15. High-speed, low-damage grinding of advanced ceramics Phase 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Kovach, J.A. [Eaton Corp., Willoughby Hills, OH (United States). Mfg. Technologies Center; Malkin, S. [Univ. of Massachusetts (United States)

    1995-03-01

    In manufacture of structural ceramic components, grinding costs can comprise up to 80% of the entire manufacturing cost. Most of these costs arise from the conventional multi-step grinding process with numerous grinding wheels and additional capital equipment, perishable dressing tools, and labor. In an attempt to reduce structural ceramic grinding costs, a feasibility investigation was undertaken to develop a single step, roughing-finishing process suitable for producing high-quality silicon nitride ceramic parts at high material removal rates at lower cost than traditional, multi-stage grinding. This feasibility study employed combined use of laboratory grinding tests, mathematical grinding models, and characterization of resultant material surface condition. More specifically, this Phase 1 final report provides a technical overview of High-Speed, Low-Damage (HSLD) ceramic grinding and the conditions necessary to achieve the small grain depths of cut necessary for low damage grinding while operating at relatively high material removal rates. Particular issues addressed include determining effects of wheel speed and material removal rate on resulting mode of material removal (ductile or brittle fracture), limiting grinding forces, calculation of approximate grinding zone temperatures developed during HSLD grinding, and developing the experimental systems necessary for determining HSLD grinding energy partition relationships. In addition, practical considerations for production utilization of the HSLD process are also discussed.

  16. FE analysis of dynamic characteristics for mill's liners

    Science.gov (United States)

    Feng, Xianzhang; Cui, Yanmei; Jiang, Zhiqiang; Hou, Tao

    2009-07-01

    Slab side pressing is an online regulation width technology for continuous casting slab, the liner at the bottom of the framework under the larger impact force, it often can occurrence accident of liner Board broken during working of sizing press rolling mill. In order to analyze force distribution and its peak in the liner of rolling mill during side pressing, liner dynamics model is established using nonlinear function of finite element software, and the contact mode is established for liner and wheel by Hertz law theory. It yields the relations between maximal stress and tap hole in the liner, the design scheme is extracted for improving condition of linerboard's stress, and the calculated results were much inosculated with the measured values. The studied results indicated that the liner's life gets improve obviously in field.

  17. Automatic flatness control strategy with a Smith predictor for steel strip rolling

    Science.gov (United States)

    Zhang, Ruicheng; Zheng, Xin

    2011-10-01

    The simplified transfer function diagram block for a automatic flatness control (AFC) system of strip steel rolling process was investigated. For the problem of automatic flatness control (AFC) in cold tandem mills this paper proposes control techniques based on Smith predictor to compensate for the numerous delays present in the mill. After a Smith predictor was used to the AFC system, the control laws were deduced for both proportional and integral regulators. Control algorithms are tested in simulation considering a tandem mill with four stands as a benchmark, and results are shown to demonstrate the performance of the proposed schemes.

  18. Modeling, simulation and identification for control of tandem cold metal rolling

    Directory of Open Access Journals (Sweden)

    Péricles Guedes Alves

    2012-12-01

    Full Text Available This paper describes a modeling procedure for tandem cold metal rolling, including the linearization step and system identification for control. The tandem cold rolling process is described by a mathematical model based on algebraic equations developed for control purposes and empirical relations. A state-space model is derived and detailed analyses in open loop are presented, concerning the sensitivity with regard to the variations in process parameters and results for the application of a new subspace identification method are compared with classical methodologies. Therefore, this work intents to be a contribution for developments in new control strategies for tandem cold rolling process that offer the potential to reduce the design efforts, the commissioning time and maintenance in rolling mills. The preliminary results obtained with this model have shown reasonable agreement with operational data presented at literature for industrial cold rolling process.

  19. Robotic Instrument for Grinding Rocks Into Thin Sections (GRITS)

    Science.gov (United States)

    Paulsen, Gale; Zacny, Kris; Dreyer, Christopher B.; Szucs, Attila; Szczesiak, Matt; Santoro, Chris; Craft, Jack; Hedlund, Magnus; Skok, John

    2013-06-01

    We have developed a rock grinding and polishing mechanism for in situ planetary exploration based on abrasive disks, called Grinding Rocks Into Thin Sections (GRITS). Performance characteristics and design considerations of GRITS are presented. GRITS was developed as part of a broader effort to develop an in situ automated rock thin section (ISARTS) instrument. The objective of IS-ARTS was to develop an instrument capable of producing petrographic rock thin sections on a planetary science spacecraft. GRITS may also be useful to other planetary science missions with in situ instruments in which rock surface preparation are necessary.

  20. INVESTIGATION OF SURFACE TEMPERATURE IN HIGH-EFFICIENCY DEEP GRINDING

    Institute of Scientific and Technical Information of China (English)

    Zhao Henghua; Cai Guangqi; Jin Tan

    2005-01-01

    A new thermal model with triangular heat flux distribution is given in high-efficiency deep grinding. The mathematical expressions are driven to calculate the surface temperature. The transient behavior of the maximum temperature on contact area is investigated in different grinding conditions with a J-type thermocouple. The maximum contact temperatures measured in different conditions are found to be between 1 000 ℃ and 1 500 ℃ in burn-out conditions. The experiment results show good agreement with the new thermal model.