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Stress distribution and fatigue life of built-up sleeved backup roll

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Journal of Central South University 2012年第8期19卷 2173-2178页

作者：朱忠英孙登月许石民 National Engineering Technology Research Center of cold rolling Strip Equipment and Technology Yanshan University

The advantage of built-up sleeved backup roll was described. Based on the stress distribution analysis and simulation for the built-up sleeved backup roll by using finite element method, the effects of roll sleeve thickness and shrink range on the stress-strain field were studied. Finally, based on the methodology and strategy of the fatigue analysis, fatigue life of backup roll was estimated by using the stress-strain data obtained through finite element simulation. The results show that roll sleeve thickness and shrink range have a great influence on sleeve stress distribution of built-up sleeved roll. Under the circumstance of ensuring transferring enough torque, the shrink range should be kept small. However, thicker roll sleeve has longer roll service life when the shrink range is constant.

关键词： built-up sleeved backup roll stress-strain analysis finite element method shrink range fatigue life

Polyploidy Induction and Morphological Characteristics in the Asiatic Hybrid Lily(Lilium *** dazzling)

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Journal of Northeast Agricultural University(English Edition) 2024年第2期31卷 24-33页

作者： Xiang Yixun Chen Mingxuan Chen Jianguo Yu Zhenyu Zhang Jinzhu Yang Tao Che Daidi Fan Jinping College of Horticulture and Landscape Architecture Northeast Agricultural UniversityHarbin 150030China Key Laboratory of cold Region Landscape plants and Applications Harbin 150030China

The Asiatic hybrid lily cultivar Lilium dazzling(family Liliaceae)is a perennial herbaceous bulbous plant with bright yellow flowers of ornamental *** also shows resistance to diseases and abiotic stress,making it an ideal parent for breeding *** study established a sterile culture system using scales of dazzling lily as explants to induce *** buds growing to 1 cm were treated with different concentrations of colchicine(125,250 and 500μmol·L-1),pendimethalin or trifluralin(100,200 and 300μmol·L-1,respectively)for 12,24 and 36 *** cytometry and chromosome counting were used to identify ploidy,and the phenotype of the polyploids was examined by stomatal observation and leaf index *** increasing mutagen concentration and exposure time,the mortality and mutagenic rate *** optimal treatment group was:300μmol·L-1 trifluralin for 12 h,which resulted in 15.55%mortality rate and 42.22%induction *** polyploid plants showed a significant increase in stomata length,leaf length and leaf width,with a decrease in stomatal density compared with the control *** study provided a basis for polyploid breeding.

关键词： polyploid Asiatic hybrid lily trifluralin flow cytometry plant morphology

Strip Layer Method for Analysis of the Three-Dimensional Stresses and Spread of Large Cylindrical Shell rolling

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Chinese Journal of Mechanical Engineering 2015年第3期28卷 556-564页

作者： LIU Hongmin CHEN Suwen PENG Yan SUN Jianliang National Engineering Research Center for Equipment and Technology of cold Strip rolling Yanshan University State Key Laboratory of Metastable Materials Science & Technology Yanshan University

As the traditional forging process has many problems such as low efficiency, high consumption of material and energy, large cylindrical shell rolling is introduced. Large cylindrical shell rolling is a typical rotary forming technology, and the upper and lower rolls have different radii and speeds. To quickly predict the three-dimensional stresses and eliminate fishtail defect, an improved strip layer method is developed, in which the asymmetry of the upper and lower rolls, non-uniform deformation and stress, as well as the asymmetrical spread on the end surface are considered. The deformation zone is divided into a certain number of layers and strips along the thickness and width, respectively. The transverse displacement model is constructed by polynomial function, in order to increase the computation speed greatly. From the metal plastic mechanics principle, the three-dimensional stress models are established. The genetic algorithm is used for optimization calculation in an industrial experiment example. The results show that the rolling pressure, the normal stresses, the upper and lower friction stress distributions are not similar with those of a general plate rolling. There are two relative maximum values in rolling pressure distribution. The upper and lower longitudinal friction stresses change direction nearby the upper and lower neutral points, respectively. The fishtail profile of spread on the end surface is predicted satisfactorily. The reduction could be helpful to eliminate fishtail defect. The large cylindrical shell rolling example illustrates the calculation results acquired rapidly are good agreements with the finite element simulation and experimental values of previous study. A highly effective and reliable three-dimensional simulation method is proposed for large cylindrical shell rolling and other asymmetrical rolling.

关键词： large cylindrical shell rolling strip layer method three-dimensional stresses rolling pressure friction stress spread

Texture Evolution of Columnar Grains in Electrical Steel During Hot rolling

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Journal of Iron and Steel Research International 2013年第10期20卷 99-106页

作者： SHAO Yuan-yuan YANG Ping FU Yong-jun MAO Wei-min School of Materials Science and Engineering University of Science and Technology Beijing cold rolling Silicon Steel Division Angang Steel Company Limited

Columnar grains in cast slabs of electrical steel show strong anisotropy in grain orientation and morphology and thus influence the subsequent microstructure and texture after hot rolling significantly. The texture evolution of hot rolled sheets containing initial columnar grains with their 〈100〉 directions approximately parallel to the rolling direction （RD）, transverse direction （TD） and normal direction （ND） of the hot rolled sheets was investigated by using EBSD technique. The results indicated that, whatever the initial texture of the columnar grains was, typical Goss, brass-type and copper-type shear texture component could develop in shear-deformed surface region. The copper-type texture formed under the maximum shearing force with the fine, sheared or dynamically recrystallized grains, and Goss grains were mainly elongated and deformed grains, while brass grains behaved between them. Ad- ditionally, the rotating relationship of the three types of shear textures was different due to the restriction of grain boundaries. In homogenously deformed center region, the RD sample contained more {112}〈110^-〉 grains, and TD sample was covered by {100} textures such as {100}〈011〉 and {100}〈021〉 with coarse grains, while the ND sample developed many {100}〈001〉 grains which were attributed to more {100} grains in the initial sample. Re- markable texture transition occurred on both sides of grain boundaries when {110} grains were adjacent to mfiber texture grains. It was found that significant texture gradient and preferred distribution of rotating axis existed in the soft orientation grains on the α- fiber when the grains neighbored hard grains on γ-fiber.

关键词： electrical steel columnar grain hot rolling texture orientation

Coupled Dynamic Modeling of Rolls Model and Metal Model for Four High Mill Based on Strip Crown Control

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Chinese Journal of Mechanical Engineering 2013年第1期26卷 144-150页

作者： SUN Jianliang PENG Yan LIU Hongmin National Engineering Research Center for Equipment and Technology of cold Strip rolling Yanshan University State Key Laboratory of Metastable Materials Science & Technology Yanshan University

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 roiling 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 roils 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-13 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 str

关键词： strip crown transverse vibration of rolls dynamic simulation dynamic conservation of material flow

Effect of Ball Scribing on Magnetic Barkhausen Noise of Grain-oriented Electrical Steel

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Journal of Materials Science & Technology 2013年第7期29卷 673-677页

作者： Hao Wang Changsheng Li Tao Zhu Ban Cai Gang Huo Nasir Mohamed State Key Laboratory of rolling and Automation Northeastern University Wolfson Centre for Magnetics Cardiff UniversityCardiff CF24 3AAUK Benxi Steel Posco cold Strip rolling Co.Ltd

Effect of ball scribing on magnetic Barkhausen noise （MBN） of conventional grain-oriented （CGO） and high- permeability grain-oriented （HGO） electrical steel was investigated. The results showed that after ball scribing, root mean square of MBN （MBNrms） of CGO electrical steel increased 9.8% with 4 mm scribing spacing at 1.2 T, and that of HGO electrical steel apparently decreased 17.3% with 16 mm scribing spacing at 1.2 T. Through the formation and development of free magnetic poles and secondary magnetic domains due to compressive stress, primary magnetic domain space of grain-oriented electrical steel becomes smaller, which reflects as a variation of MBN in the macroscopic magnetic properties. Through correlation formula derivation of MBNrms and equilibrium distance between domain walls, effect of domain refinement on grain-oriented electrical steel was also interpreted, and optimum equilibrium distance between domain walls was determined.

关键词： Ball scribing Grain-oriented electrical steel Magnetic Barkhausen noise Domain refinement

Impacts of surfactant-based adjuvants on spray droplet size,drift distance,and deposition efficiency

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International Journal of Agricultural and Biological Engineering 2024年第3期17卷 50-58页

作者： Changwei Gong Yue Liu Yu Ma Qiulin Wang Zhengze Xu Xuegui Wang Xiaoxu Zhan Litao Shen Biorational Pesticide Research Lab Sichuan Agricultural UniversityChengdu 611130China Anyang Quanfeng Aviation plant Protection Technology Co. LtdAnyang 455000HenanChina

The application of anti-drift nozzles,such as air-induction nozzles,is the most common recommendation for reducing spray drift;To reduce the risk of coarse droplets bouncing and rolling produced by anti-drift nozzles,various types of adjuvants were screened by comparing their atomization performance,surface tension and contact angle,in order to identify favourable adjuvants that are compatible with anti-drift *** was found from the study results that the addition of 50%neem crude oil emulsifiable concentrate(neem oil),isomeric alcohol ethoxylates and BYK-405 all significantly decreased distribution span(S)and the percentage of droplet size less than 150μm(ΦVol_(<150μm))values,but significantly promoted the median volume(D_(50))*** the surface tension measurement results showed that all tested adjuvants significantly reduced the surface tension,while neem oil,FC4430 and silwetl-77 were observed with a most significant effects;Furthermore,all tested adjuvants except BYK-051N could also significantly decrease the contact angle,and the difference between neem oil,FC4430 and silwetl-77 was *** tunnel test results clearly demonstrated that the application of IDKA(a combination of air-induction nozzle IDK120-01 and neem oil)substantially decreased the drift deposition amount;In addition,the field experiments revealed that IDKA possessed a significantly improved deposition amount per unit area on canopy or bottom,leading to a more effective *** results suggest that the use of IDK120-01 nozzle and neem oil can effectively reduce spray drift,lessen surface tension and enhance spreading.

关键词： spray drift unmanned aerial vehicles air-induction nozzles surface tension contact angle

Determination of interference fit value on entire roller embedded shapemeter roll

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Journal of Central South University 2014年第12期21卷 4503-4508页

作者：吴海淼刘宏民于丙强杨利坡 National Engineering Research Center for Equipment and Technology of cold rolling Strip Yanshan University College of Mechanical and Electrical Engineering Hebei University of Engineering

For entire roller embedded shapemeter roll, the relationship between the value of interference fit and the sensor pre-pressure, and the pressure transfer performance of shapemeter roll were analyzed by elasticity theory during the cold reversible rolling process. Considering the influence of strip temperature on the interference fit, the distributions of contact pressure of the framework's top surface and the sensor pre-pressure on different values of interference fit were analyzed by the finite element technology. The results show that the contact pressure of the framework's top surface and the sensor pre-pressure increase with the increase of the value of interference fit. When the value of interference fit is between 0.05 mm and 0.09 mm, roll body's inner hole surface, the framework and pressure magnetic sensitive component don't separate from each other, and the sensor works in the linear segment of characteristic curve, so the normal operation of shapemeter roll is guaranteed.

关键词： reversible rolling shapemeter roll value of interference fit contact pressure finite element

Analysis of Wear Mechanism and Influence Factors of Drum Segment of Hot rolling Coiler

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Chinese Journal of Mechanical Engineering 2013年第2期26卷 351-355页

作者： ZHANG Jian PENG Yan LIU Hongmin LIU Yunfei National Engieering Research Center for Equipment and Technology of cold rolling Strip Yanshan University State Key Laboratory of Metastable Materials Science and Technology Yanshan University

Because the work environment of segment is complex, and the wear failures usually happen, the wear mechanism corresponding to the load is a key factor for the solution of this problem. At present, many researchers have investigated the failure of segment, but have not taken into account the compositive influences of matching and coiling process. To investigate the wear failure of the drum segment of the hot rolling coiler, the MMU-5G abrasion tester is applied to simulate the wear behavior under different temperatures, different loads and different stages, and the friction coefficients and wear rates are acquired. Scanning electron microscopy（SEM） is used to observe the micro-morphology of worn surface, X-ray energy dispersive spectroscopy（EDS） is used to analyze the chemical composition of worn surface, finally the wear mechanism of segment in working process is judged and the influence regulars of the environmental factors on the material wear behaviors are found. The test and analysis results show that under certain load, the wear of the segment changes into oxidation wear from abrasive wear step by step with the temperature increases, and the wear degree reduces; under certain temperature, the main wear mechanism of segment changes into spalling wear from abrasive wear with the load increases, and the wear degree slightly increases. The proposed research provides a theoretical foundation and a practical reference for optimizing the wear behavior and extending the working life of segment.

关键词： friction coefficient wear rate micro-morphology wear mechanism wear resistance