It is difficult to obtain the desired strip shape using Sendzimir rolling mills because small diameter work rolls can be easily deformed by the roiling force. To control the strip shape effectively, it is important to...It is difficult to obtain the desired strip shape using Sendzimir rolling mills because small diameter work rolls can be easily deformed by the roiling force. To control the strip shape effectively, it is important to understand the relationship between the behavior of the shape actuator and the variation of the strip shape. A numerical model based on the contact element method was proposed for the prediction of strip shape. In this numerical model, the re- lationships between the actuating forces, the roll deflections, the thickness profiles of the entry and exit sides, and the strip shape were considered. The proposed numerical model for strip shape prediction was evaluated by computer simulation and experiment with respect to various AS-U roll and first intermediate roll positions.展开更多
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 t...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.展开更多
The theory of metal plastic deformation is an important part of the strip shape control theories. In order to control the shape and gauge accurately during cold thin strip rolling, the mechanism of the metal lateral f...The theory of metal plastic deformation is an important part of the strip shape control theories. In order to control the shape and gauge accurately during cold thin strip rolling, the mechanism of the metal lateral flow must be revealed clearly. Therefore, the lateral displacement of thin strip was studied by the grid method. Those grids with a line thickness of 10 μm and clear boundaries were successfully manufactured on the strip surface using lithography. Then, the effects of reduction, front and back tension, and taper angle of the first intermediate roll on the metal lateral flow were studied. The strip shape was calculated with and without considering the lateral displacement; furthermore, the calculations were compared with the measured results. The results show that the calculations with considering the lateral displacement are closer to the measured results. In addition, the comparison of finite element analysis results with the experimental results indicates that the test method was reliable.展开更多
A theoretical model about the secondary deformation is developed by the combination of analytical and experimental approaches. A system simulation based on the model is completed to predict the strip profile after the...A theoretical model about the secondary deformation is developed by the combination of analytical and experimental approaches. A system simulation based on the model is completed to predict the strip profile after the interstand deformation. On the other hand, comprehensive experiments and quantitative comparisons are made to calibrate the model for a wide variety of products. As a result, the correction of the model has been verified by the actual rolling data from production mill and it is helpful to improve the strip shape control.展开更多
The elasticity deformation of rolls was analyzed by means of two-dimensional finite element method （FEM） with variable thickness. Three typical mills were used as objects for analysis. A thorough study was done on t...The elasticity deformation of rolls was analyzed by means of two-dimensional finite element method （FEM） with variable 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. 2008 University of Science and Technology Beijing. All rights reserved.展开更多
The entire roller inlayed block intelligence cold strip shape meter is developed successfully in this paper,which can stably work chronically in the cold rolling workshop,the independent innovation of the key technolo...The entire roller inlayed block intelligence cold strip shape meter is developed successfully in this paper,which can stably work chronically in the cold rolling workshop,the independent innovation of the key technology of cold strip shape measuring,the foreign technical monopoly and blockade are broken through.The structural form which is different from the international popular segmented detection roller is put forward,the entire detection roller inlayed block is developed,a group of elastic blocks in that the sense organs are installed are inlayed in the radial symmetry rectangular grooves of the detection roller body,the entire roller structure is composed of elastic pieces and the roller body,the scratch of the strip surface due to different thermal expansion of the traditional detection roller measuring unit is avoided effectively.The signal transmission form which is different form the international popular dry slip ring is put forward,the spray wet slip ring is developed,slip ring and detection roller can be taken down and installed as possibly as fast,so the maintain is convenient,while through the section auto-spray cleaning,lubrication and cooling, the service life is remarkable improved and the outside interference signal is reduced.The signal processing form which is different form the international popular gathering card is put forward,the embedded DSP shape signal processing hardware system is developed,the electromagnet,temperature,humidity and vibration's interference of industry practice to shape transmission signal can be effectively avoided,which can guarantee the instantaneity and measured precision of shape measured signal.The shape signal processing software system whose function contains error compensation,pattern recognition,establishment of the target shape and the closed-loop control calculation is built,the shape meter' computer human interaction is friendly,and function of shape meter is strong,at the same time the intellectualized level of the shape meter is improved.Now,this shape meter has been successfully applied on the 1 250 mm cold strip mill of Angang Steel Company Limited,the long-term operating testing is done,every guide line achieves the anticipative effect,the measuring precision is high and the measuring signal is stable and reliable,the shape meter is tested on high speed,big tension,changed wrap angle and big depressed complicated working conditions,any scratch of the detection roller surface and the strip surface is not appearing,it can completely adapt well to the industrial production environment,reaching the international advanced level.展开更多
In this study,the authors proposed a new algorism which can simultaneously meets the strip shape control criterion and the strip crown control criterion.Based on the new algorism,the pass schedule is optimized to maxi...In this study,the authors proposed a new algorism which can simultaneously meets the strip shape control criterion and the strip crown control criterion.Based on the new algorism,the pass schedule is optimized to maximize the allowable PC angle range.To calculate the objective value for optimization of pass schedule,a slab method has been integrated with the roll stack deformation to simulate the strip profile.展开更多
In specific condition, when wrapping angle of cold rolling strip covering surface of shape detecting roll dynamically changes, online radial compression of the shape detecting roll is changed too, and it seriously aff...In specific condition, when wrapping angle of cold rolling strip covering surface of shape detecting roll dynamically changes, online radial compression of the shape detecting roll is changed too, and it seriously affects online shape detecting precision of cold strip. Based on the latest intelligent shape meter developed by Yanshan University, using PSO-BP neural network and actual working condition datum, the cold strip online dynamic wrapping angle compensation model is established, and successfully applied in 1250 mm 6-high cold mill, remarkable results are achieved. The error between calculated values and measured values of total tensions is within 3 %展开更多
A study on roll gap profile (strip profile) control was accomplished in a1700 mm single-stand temper mill. Some critical problems such as the deviation of work roll contourcaused by grinding and wear, the effectivenes...A study on roll gap profile (strip profile) control was accomplished in a1700 mm single-stand temper mill. Some critical problems such as the deviation of work roll contourcaused by grinding and wear, the effectiveness of work roll bending were discussed. Using a finiteelement 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 somespecial features of flatness control in the temper mill: during temper rolling, roll deformation isslight due to small rolling load, and the loaded roll gap profile mainly depends on work rollcontour, while the backup roll has a little effect on gap crown; the effect of bending force ongauge can not be ignored due to the coupling between flatness control and gauge control. A new rollcontour 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 workroll bender, higher rolling stability, better strip profile and flatness quality.展开更多
Shape is an important quality index of cold rolling strip. Up to now, many problems in the shape control domain have not been solved satisfactorily, and a review on the research progress in the shape control domain ca...Shape is an important quality index of cold rolling strip. Up to now, many problems in the shape control domain have not been solved satisfactorily, and a review on the research progress in the shape control domain can help to seek new breakthrough directions. In the past 10 years, researches and applications of shape control models, shape control means, shape detection technology, and shape con- trol system have achieved significant progress. In the aspect of shape control models, the researches in the past improve the accuracy, speed and robustness of the models. The intelligentization of shape control models should be strengthened in the future. In the aspect of the shape control means, the researches in the past focus on the roll opti- mization, mill type selection, process optimization, local strip shape control, edge drop control, and so on. In the future, more attention should be paid to the coordination control of both strip shape and other quality indexes, and the refinement of control objective should be strengthened. In the aspects of shape detection technology and shape control system, some new types of shape detection meters and shape control systems are developed and have successfully indus- trial applications. In the future, the standardization of shape detection technology and shape control system should be promoted to solve the problem of compatibility. In general,the four expected development trends of shape control for cold roiling strip in the future are intelligentization, coordi- nation, refinement, and standardization. The proposed research provides new breakthrough directions for improv- ing shape quality.展开更多
Some unavoidable factors in the process of cold strip shape measurement interfere with the shape meter, so the shape measuring results cannot reflect the true shape of the strip and the measuring precision is low. The...Some unavoidable factors in the process of cold strip shape measurement interfere with the shape meter, so the shape measuring results cannot reflect the true shape of the strip and the measuring precision is low. The influ- ences of the measuring error of the strip edges, the transverse temperature difference of the strip, the deflection of shape detection roller, and the shape of the strip coil on the shape measuring results were analyzed in detail, and the corresponding compensation models were established. The simulation calculation and analysis were carried out on a cold strip mill, and a number of disciplinarian cognitions were obtained.展开更多
Shape setup （SSU） system is the core technology for hot strip mill （HSM）. A precise SSU system was used to improve the strip quality for HSM. The function of SSU, setup, and feedback was introduced. The main mathe...Shape setup （SSU） system is the core technology for hot strip mill （HSM）. A precise SSU system was used to improve the strip quality for HSM. The function of SSU, setup, and feedback was introduced. The main mathematical models of roll gap profile and longitudinal strain difference are set up. Strip profile allocation strategy was researched according to the SSU system of a domestic 1 700 mm HSM. The SSU system was put into practical use and the measurement results showed that strip flatness variation and strip profile variation could be controlled in target scope.展开更多
Quantitative level evaluation of cold-rolled strip was significant for the shape control and the product structure optimization. Based on the probability statistics method and the shape pattern recognition method, the...Quantitative level evaluation of cold-rolled strip was significant for the shape control and the product structure optimization. Based on the probability statistics method and the shape pattern recognition method, the shape evaluation model of cold-rolled strip was established to evaluate real-time shape of the online strip. The model was embedded in the shape control system, and the online strip shape state was real-time observed whether to meet the technical indicators, so the shape level could be identified and evaluated. Based on the shape evaluation indicators, the shape component could be well controlled to improve the shape hit rate and the control stability, so that the rolled strip shape could meet the technical requirements. At a 1050 cold strip mill, the shape data of the scene typical specifications strip were online collected and real-time evaluated, and the hit of macro shape in less than 8 I was 68.44%, indicating that the mill shape control had considerable room for improvement, as well as the evaluation method was feasible and practical for quantitative evaluation of the strip shape. So the new evaluation model has important guiding significance to increase value-added and reduce product quality objection.展开更多
The aim is to propose and design a kind of novel impact absorption devices using constant-force elements made from Ni Ti shape memory alloy( SMA) strips for safety protection.The availability evaluation results indica...The aim is to propose and design a kind of novel impact absorption devices using constant-force elements made from Ni Ti shape memory alloy( SMA) strips for safety protection.The availability evaluation results indicate that the constant-force elements can absorb over one half of the impact energy for its martensite transformation and thus the maximum impact force is reduced by nearly 80%.Compared with the ordinary cylindrical compression spring,the device's maximum impact force is reduced by nearly 50%,otherwise it has a very compact structure and insensitivity to the varying impact,and thus it is especially suitable for narrow space and safety purpose.展开更多
The torsional impact response of a penny-shaped crack in a nonhomogeneous strip is considered. The shear modulus is assumed to be functionally graded such that the mathematics is tractable. Laplace and Hankel transfor...The torsional impact response of a penny-shaped crack in a nonhomogeneous strip is considered. The shear modulus is assumed to be functionally graded such that the mathematics is tractable. Laplace and Hankel transforms were used to reduce the problem to solving a Fredholm integral equation. The crack tip stress field is obtained by considering the asymptotic behavior of Bessel function. Explicit expressions of both the dynamic stress intensity factor and the energy density factor were derived.And it is shown that, as crack driving force, they are equivalent for the present crack problem. Investigated are the effects of material nonhomogeneity and (strip's) highness on the dynamic fracture behavior. Numerical results reveal that the peak of the dynamic stress intensity factor can be suppressed by increasing the nonhomogeneity parameter of the shear modulus, and that the dynamic behavior varies little with the adjusting of the strip's highness.展开更多
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...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 ac- curacy 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 re- quirement） 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.展开更多
The strip flatness and crown control model is the foundation of automatic strip shape control. Considering the metal transverse flows and the inter stand second deformation, the trip flatness and crown control model h...The strip flatness and crown control model is the foundation of automatic strip shape control. Considering the metal transverse flows and the inter stand second deformation, the trip flatness and crown control model has been developed, which can be applied to CVC mills and PC mills as well as normal four-high mills. The strip flatness and crown control model has high precision, and has been successfully applied to the automatic strip shape control system reconstruction of Tangshan Ganglu 1 250 mm hot strip plant.展开更多
In order to improve the quality of the strip for the hot continuous rolling, the high accuracy set-up control must be applied to production. In the paper, we analyze the RFC (profile and flatness control) system and s...In order to improve the quality of the strip for the hot continuous rolling, the high accuracy set-up control must be applied to production. In the paper, we analyze the RFC (profile and flatness control) system and simulate the set-up process. Calculation results are in agreement to the actual measurements. It is the basis on the developing model.展开更多
To analyze and solve the problem of single-side long edge of hot rolled strip in certain domestic factory, the asymmetrical deformation of rolls and strip in asymmetrical stiffness mill stand based on slit beam model,...To analyze and solve the problem of single-side long edge of hot rolled strip in certain domestic factory, the asymmetrical deformation of rolls and strip in asymmetrical stiffness mill stand based on slit beam model, the strip profile and rolling force distribution at the exit of asymmetric stiffness stand mill were calculated using influence function method. Considering the character of in-site equipment and technology, a scheme of adjusting load distribution in finishing mill was made and the experiment was applied. Comparison of strip profile between new load distribution and the old one shows that the method can solve single-side long edge problem well.展开更多
There are very few researches on the shape standard curve currently,and they merely remain on the level of description of the general concept and production experiences,lacking of the in-depth theoretical analysis,and...There are very few researches on the shape standard curve currently,and they merely remain on the level of description of the general concept and production experiences,lacking of the in-depth theoretical analysis,and the concrete principle,method and steps for determining the shape standard curve are not put forward,therefore,they are not applicable in industrial production.This is the weakest spot in the research on the basic shape theory.In this paper,the basic shape standard curve and the transverse distribution curve of the exit thickness are attained with stepwise optimization,which is based on the theoretical calculation method of the shape standard curve of strip mills proposed by authors.By calculating the shape discrimination model and the shape forecast model separately,the simultaneous iterative calculation by the previous method is avoided,and the speed and stability of calculation are improved.The compensation models of the transverse temperature difference of the strip,the shape detection roller deflection and the shape of the strip coil are established,respectively,meantime,the basic shape standard curves are compensated,and the relatively perfect theoretical establishment method of the shape standard curve is formed.The simulation and calculation are done on a 1 220 mm five-stand cold strip tandem mill.The simulation and calculation result shows that the principle,method and steps for determining the shape standard curve are correct and feasible,and the correctness of theoretical analysis and calculation is verified.This paper proposes an idea and a method for the establishment of the shape standard curve in the rolling processes of cold strip mills,which develop the theory and model of the shape standard curve and improve the quality and efficiency of the shape control in the rolling processes of cold strip mills.展开更多
基金Item Sponsored by Korea Science and Engineering Foundation(KOSEF)Grant Funded by Korea Government(MEST)(2010-0022521)
文摘It is difficult to obtain the desired strip shape using Sendzimir rolling mills because small diameter work rolls can be easily deformed by the roiling force. To control the strip shape effectively, it is important to understand the relationship between the behavior of the shape actuator and the variation of the strip shape. A numerical model based on the contact element method was proposed for the prediction of strip shape. In this numerical model, the re- lationships between the actuating forces, the roll deflections, the thickness profiles of the entry and exit sides, and the strip shape were considered. The proposed numerical model for strip shape prediction was evaluated by computer simulation and experiment with respect to various AS-U roll and first intermediate roll positions.
基金Item Sponsored by National High Technology Research and Development Programof China(2009AA04Z163)
文摘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.
基金The authors gratefully acknowledge the support of the National Natural Science Foundation of China （51474190）, Natural Science Foundation of HeBei Province （E2015203311）, and Taiyuan City Science and Technology Major Projects （170203）.
文摘The theory of metal plastic deformation is an important part of the strip shape control theories. In order to control the shape and gauge accurately during cold thin strip rolling, the mechanism of the metal lateral flow must be revealed clearly. Therefore, the lateral displacement of thin strip was studied by the grid method. Those grids with a line thickness of 10 μm and clear boundaries were successfully manufactured on the strip surface using lithography. Then, the effects of reduction, front and back tension, and taper angle of the first intermediate roll on the metal lateral flow were studied. The strip shape was calculated with and without considering the lateral displacement; furthermore, the calculations were compared with the measured results. The results show that the calculations with considering the lateral displacement are closer to the measured results. In addition, the comparison of finite element analysis results with the experimental results indicates that the test method was reliable.
文摘A theoretical model about the secondary deformation is developed by the combination of analytical and experimental approaches. A system simulation based on the model is completed to predict the strip profile after the interstand deformation. On the other hand, comprehensive experiments and quantitative comparisons are made to calibrate the model for a wide variety of products. As a result, the correction of the model has been verified by the actual rolling data from production mill and it is helpful to improve the strip shape control.
文摘The elasticity deformation of rolls was analyzed by means of two-dimensional finite element method （FEM） with variable 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. 2008 University of Science and Technology Beijing. All rights reserved.
文摘The entire roller inlayed block intelligence cold strip shape meter is developed successfully in this paper,which can stably work chronically in the cold rolling workshop,the independent innovation of the key technology of cold strip shape measuring,the foreign technical monopoly and blockade are broken through.The structural form which is different from the international popular segmented detection roller is put forward,the entire detection roller inlayed block is developed,a group of elastic blocks in that the sense organs are installed are inlayed in the radial symmetry rectangular grooves of the detection roller body,the entire roller structure is composed of elastic pieces and the roller body,the scratch of the strip surface due to different thermal expansion of the traditional detection roller measuring unit is avoided effectively.The signal transmission form which is different form the international popular dry slip ring is put forward,the spray wet slip ring is developed,slip ring and detection roller can be taken down and installed as possibly as fast,so the maintain is convenient,while through the section auto-spray cleaning,lubrication and cooling, the service life is remarkable improved and the outside interference signal is reduced.The signal processing form which is different form the international popular gathering card is put forward,the embedded DSP shape signal processing hardware system is developed,the electromagnet,temperature,humidity and vibration's interference of industry practice to shape transmission signal can be effectively avoided,which can guarantee the instantaneity and measured precision of shape measured signal.The shape signal processing software system whose function contains error compensation,pattern recognition,establishment of the target shape and the closed-loop control calculation is built,the shape meter' computer human interaction is friendly,and function of shape meter is strong,at the same time the intellectualized level of the shape meter is improved.Now,this shape meter has been successfully applied on the 1 250 mm cold strip mill of Angang Steel Company Limited,the long-term operating testing is done,every guide line achieves the anticipative effect,the measuring precision is high and the measuring signal is stable and reliable,the shape meter is tested on high speed,big tension,changed wrap angle and big depressed complicated working conditions,any scratch of the detection roller surface and the strip surface is not appearing,it can completely adapt well to the industrial production environment,reaching the international advanced level.
文摘In this study,the authors proposed a new algorism which can simultaneously meets the strip shape control criterion and the strip crown control criterion.Based on the new algorism,the pass schedule is optimized to maximize the allowable PC angle range.To calculate the objective value for optimization of pass schedule,a slab method has been integrated with the roll stack deformation to simulate the strip profile.
基金Item Sponsored by National Science and Technology Support Plan of China(2007BAF02B10)Natural Science Foundation of Hebei Province of China(E2011203004)
文摘In specific condition, when wrapping angle of cold rolling strip covering surface of shape detecting roll dynamically changes, online radial compression of the shape detecting roll is changed too, and it seriously affects online shape detecting precision of cold strip. Based on the latest intelligent shape meter developed by Yanshan University, using PSO-BP neural network and actual working condition datum, the cold strip online dynamic wrapping angle compensation model is established, and successfully applied in 1250 mm 6-high cold mill, remarkable results are achieved. The error between calculated values and measured values of total tensions is within 3 %
文摘A study on roll gap profile (strip profile) control was accomplished in a1700 mm single-stand temper mill. Some critical problems such as the deviation of work roll contourcaused by grinding and wear, the effectiveness of work roll bending were discussed. Using a finiteelement 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 somespecial features of flatness control in the temper mill: during temper rolling, roll deformation isslight due to small rolling load, and the loaded roll gap profile mainly depends on work rollcontour, while the backup roll has a little effect on gap crown; the effect of bending force ongauge can not be ignored due to the coupling between flatness control and gauge control. A new rollcontour 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 workroll bender, higher rolling stability, better strip profile and flatness quality.
基金Supported by National Key Technology Support Program of China (Grant No. 2011BAF15B00)Hebei Provincial Natural Science Foundation of China (Grant No. E2016203482)+1 种基金Hebei Provincial Science and Technology Research Foundation of China (Grant No. ZD2014034)Youth Independent Research Program of Yanshan University of China (Grant No. 14LGA003)
文摘Shape is an important quality index of cold rolling strip. Up to now, many problems in the shape control domain have not been solved satisfactorily, and a review on the research progress in the shape control domain can help to seek new breakthrough directions. In the past 10 years, researches and applications of shape control models, shape control means, shape detection technology, and shape con- trol system have achieved significant progress. In the aspect of shape control models, the researches in the past improve the accuracy, speed and robustness of the models. The intelligentization of shape control models should be strengthened in the future. In the aspect of the shape control means, the researches in the past focus on the roll opti- mization, mill type selection, process optimization, local strip shape control, edge drop control, and so on. In the future, more attention should be paid to the coordination control of both strip shape and other quality indexes, and the refinement of control objective should be strengthened. In the aspects of shape detection technology and shape control system, some new types of shape detection meters and shape control systems are developed and have successfully indus- trial applications. In the future, the standardization of shape detection technology and shape control system should be promoted to solve the problem of compatibility. In general,the four expected development trends of shape control for cold roiling strip in the future are intelligentization, coordi- nation, refinement, and standardization. The proposed research provides new breakthrough directions for improv- ing shape quality.
基金Item Sponsored by National Science and Technology Support Plan of China (2007BAF02B10)Provincial Natural Science Foundation of Hebei of China (E2006001038)
文摘Some unavoidable factors in the process of cold strip shape measurement interfere with the shape meter, so the shape measuring results cannot reflect the true shape of the strip and the measuring precision is low. The influ- ences of the measuring error of the strip edges, the transverse temperature difference of the strip, the deflection of shape detection roller, and the shape of the strip coil on the shape measuring results were analyzed in detail, and the corresponding compensation models were established. The simulation calculation and analysis were carried out on a cold strip mill, and a number of disciplinarian cognitions were obtained.
基金Item Sponsored by National Natural Science Foundation of China (50534020)
文摘Shape setup （SSU） system is the core technology for hot strip mill （HSM）. A precise SSU system was used to improve the strip quality for HSM. The function of SSU, setup, and feedback was introduced. The main mathematical models of roll gap profile and longitudinal strain difference are set up. Strip profile allocation strategy was researched according to the SSU system of a domestic 1 700 mm HSM. The SSU system was put into practical use and the measurement results showed that strip flatness variation and strip profile variation could be controlled in target scope.
基金Item Sponsored by the National Science and Technology Support Plan of China(2011BAF15B03)National Natural Science Foundation of China(51305387)Hebei Province Colleges and Universities Natural Science Research Youth Foundation of China(Q2012104)
文摘Quantitative level evaluation of cold-rolled strip was significant for the shape control and the product structure optimization. Based on the probability statistics method and the shape pattern recognition method, the shape evaluation model of cold-rolled strip was established to evaluate real-time shape of the online strip. The model was embedded in the shape control system, and the online strip shape state was real-time observed whether to meet the technical indicators, so the shape level could be identified and evaluated. Based on the shape evaluation indicators, the shape component could be well controlled to improve the shape hit rate and the control stability, so that the rolled strip shape could meet the technical requirements. At a 1050 cold strip mill, the shape data of the scene typical specifications strip were online collected and real-time evaluated, and the hit of macro shape in less than 8 I was 68.44%, indicating that the mill shape control had considerable room for improvement, as well as the evaluation method was feasible and practical for quantitative evaluation of the strip shape. So the new evaluation model has important guiding significance to increase value-added and reduce product quality objection.
文摘The aim is to propose and design a kind of novel impact absorption devices using constant-force elements made from Ni Ti shape memory alloy( SMA) strips for safety protection.The availability evaluation results indicate that the constant-force elements can absorb over one half of the impact energy for its martensite transformation and thus the maximum impact force is reduced by nearly 80%.Compared with the ordinary cylindrical compression spring,the device's maximum impact force is reduced by nearly 50%,otherwise it has a very compact structure and insensitivity to the varying impact,and thus it is especially suitable for narrow space and safety purpose.
文摘The torsional impact response of a penny-shaped crack in a nonhomogeneous strip is considered. The shear modulus is assumed to be functionally graded such that the mathematics is tractable. Laplace and Hankel transforms were used to reduce the problem to solving a Fredholm integral equation. The crack tip stress field is obtained by considering the asymptotic behavior of Bessel function. Explicit expressions of both the dynamic stress intensity factor and the energy density factor were derived.And it is shown that, as crack driving force, they are equivalent for the present crack problem. Investigated are the effects of material nonhomogeneity and (strip's) highness on the dynamic fracture behavior. Numerical results reveal that the peak of the dynamic stress intensity factor can be suppressed by increasing the nonhomogeneity parameter of the shear modulus, and that the dynamic behavior varies little with the adjusting of the strip's highness.
基金the National Major Technology Equipment Research Program during the 9th Five-Year Plan Period (No.97-316-01-1).
文摘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 ac- curacy 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 re- quirement） 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.
基金Item Sponsored by National Natural Science Foundation of China (50534020)
文摘The strip flatness and crown control model is the foundation of automatic strip shape control. Considering the metal transverse flows and the inter stand second deformation, the trip flatness and crown control model has been developed, which can be applied to CVC mills and PC mills as well as normal four-high mills. The strip flatness and crown control model has high precision, and has been successfully applied to the automatic strip shape control system reconstruction of Tangshan Ganglu 1 250 mm hot strip plant.
文摘In order to improve the quality of the strip for the hot continuous rolling, the high accuracy set-up control must be applied to production. In the paper, we analyze the RFC (profile and flatness control) system and simulate the set-up process. Calculation results are in agreement to the actual measurements. It is the basis on the developing model.
文摘To analyze and solve the problem of single-side long edge of hot rolled strip in certain domestic factory, the asymmetrical deformation of rolls and strip in asymmetrical stiffness mill stand based on slit beam model, the strip profile and rolling force distribution at the exit of asymmetric stiffness stand mill were calculated using influence function method. Considering the character of in-site equipment and technology, a scheme of adjusting load distribution in finishing mill was made and the experiment was applied. Comparison of strip profile between new load distribution and the old one shows that the method can solve single-side long edge problem well.
基金supported by National Hi-tech Research and Development Program of China(863Program,Grant No.2009AA04Z143)National Science and Technology Support Plan of China(Grant No.2007BAF02B10)Hebei Provincial Great Natural Science Foundation of China(Grant No.E2006001038)
文摘There are very few researches on the shape standard curve currently,and they merely remain on the level of description of the general concept and production experiences,lacking of the in-depth theoretical analysis,and the concrete principle,method and steps for determining the shape standard curve are not put forward,therefore,they are not applicable in industrial production.This is the weakest spot in the research on the basic shape theory.In this paper,the basic shape standard curve and the transverse distribution curve of the exit thickness are attained with stepwise optimization,which is based on the theoretical calculation method of the shape standard curve of strip mills proposed by authors.By calculating the shape discrimination model and the shape forecast model separately,the simultaneous iterative calculation by the previous method is avoided,and the speed and stability of calculation are improved.The compensation models of the transverse temperature difference of the strip,the shape detection roller deflection and the shape of the strip coil are established,respectively,meantime,the basic shape standard curves are compensated,and the relatively perfect theoretical establishment method of the shape standard curve is formed.The simulation and calculation are done on a 1 220 mm five-stand cold strip tandem mill.The simulation and calculation result shows that the principle,method and steps for determining the shape standard curve are correct and feasible,and the correctness of theoretical analysis and calculation is verified.This paper proposes an idea and a method for the establishment of the shape standard curve in the rolling processes of cold strip mills,which develop the theory and model of the shape standard curve and improve the quality and efficiency of the shape control in the rolling processes of cold strip mills.
