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Compound control for speed and tension multivariable coupling system of reversible cold strip mill

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Journal of Central South University 2015年第2期22卷 529-538页

作者：方一鸣刘乐李建雄常茹 Key Laboratory of Industrial Computer Control Engineering of Hebei Province(Institute of Electrical Engineering Yanshan University) National Engineering Research Center for Equipment and Technology of cold Strip rolling(Yanshan University)

To weaken the nonlinear coupling influence among the variables in the speed and tension system of reversible cold strip mill, a compound control(CC) strategy based on invariance principle was proposed. Firstly, invariance principle was used to realize static decoupling between the speed and tension of reversible cold strip mill. Then, considering the influence caused by the time variation of steel coil radius and rotational inertia of the left and right coilers, as well as the uncertainties, a CC strategy that is composed of extended state observer(ESO) and global sliding mode control(GSMC) with backstepping adaptive was proposed,which further realized dynamic decoupling and coordination control for the speed and tension system. Theoretical analysis shows that the resulting closed-loop system is global bounded stable. Finally, the simulation was carried out on the speed and tension system of a 1422 mm reversible cold strip mill by using the actual data, and through the comparison of the other control strategies, validity of the proposed CC strategy was shown by the results.

关键词： reversible cold strip mill speed and tension system decoupling invariance principle compound control extended state observer global sliding mode control

Fabrication of nanostructure in inner-surface of AISI 304 stainless steel pipe with surface plastic deformation

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Journal of Materials Science & Technology 2018年第11期34卷 2125-2130页

作者： Hongwang Zhang Yiming Zhao Yuhui Wang Huaxin Yu Chunling Zhang National Engineering Research Center for Equipment and Technology of cold Strip rolling College of Mechanical EngineeringYanshan University National Key Laboratory of Metastable Materials Science and Technology Yanshan University

In the present investigation, a pipe inner-surface grinding（PISG） technique was developed to fabricate nanostructure in the inner-surface of an austenitic 304 stainless steel pipe. PISG was performed by high speed shearing with hard sphere tips, leading to gradient distribution of strain, strain rate and strain gradient along depth. Nano-austenite with an average boundary spacing of 20 nm was generated, followed by deformation microstructure characterized by shear bands, multi-and uni-directional twins and planar dislocation arrays. Deformation induced grain refinement of austenitic 304 stainless steel with low stacking fault energy（SFE） covering 4–5 order＇s magnitude of length scales toward nanometer regime was unified.

关键词： Nanostrucutre Pipe inner-surface grinding Stainless steel Plastic deformation Nano-austenite

Properties and Microstructure of One-Step cold Rolled Steel Strip for Shadow Mask

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Journal of Iron and Steel Research International 2008年第5期15卷 77-80,94页

作者： LIANG Xuan LI Jun PENG Ying-hong School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200030 China cold rolling Mill Baoshan Iron and Steel Co Ltd Shanghai 200941 China

The effect of recrystallization annealing temperature on the properties and microstructure of one-step cold rolled steel strip for shadow mask was studied. The results showed that there was no yield point elongation when the tensile tests were performed on the samples for annealing temperatures ranging from 750 ℃ to 810 ℃. Moreover, increasing annealing temperature resulted in large grains, which was beneficial to the formability and magnetic property of steel strips. On the other hand, when the sample was annealed at 840 ℃, its microstructure showed ununiforrnity with 0.04 % yield point elongation, which was not good for the function of the shadow mask. Therefore, the proper recrystallization annealing temperature was about 810 ℃ for the present steel strip for shadow mask.

关键词： steel strip shadow mask mechanical property microstructure recrystallization annealing

Dynamic Recrystallization Behavior of Q370qE Bridge Steel

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Chinese Journal of Mechanical Engineering 2023年第5期36卷 330-340页

作者： Caiyi Liu Shicheng Liang Yan Peng Jianliang Sun Carlo Mapelli Silvia Barella Andrea Gruttadauria Marco Belf Ludovica Rovatti National Engineering Research Center for Equipment and Technology of cold Roll Strip rolling Yanshan UniversityQinhuangdao 066004China Department of Mechanical Engineering Politecnico di Milano20156 MilanItaly

Bridge steel has been widely used in recent years for its excellent performance. Understanding the high-temperature Dynamic Recrystallization (DRX) behavior of high-performance bridge steel plays an important role in guiding the thermomechanical processing process. In the present study, the hot deformation behavior of Q370qE bridge steel was investigated by hot compression tests conducted on a Gleeble 3800-GTC thermal-mechanical physical simulation system at temperatures ranging from 900 ℃ to 1100 ℃ and strain rates ranging from 0.01 s^(−1) to 10 s^(−1). The obtained results were used to plot the true stress-strain and work-hardening rate curves of the experimental steel, with the latter curves used to determine the critical strains for the initiation of DRX. The Zener-Hollomon equation was subsequently applied to establish the correspondence between temperature and strain rate during the high-temperature plastic deformation of bridge steel. In terms of the DRX volume fraction solution, a new method for establishing DRX volume fraction was proposed based on two theoretical models. The good weathering and corrosion resistance of bridge steel lead to difculties in microstructure etching. To solve this, the MTEX technology was used to further develop EBSD data to characterize the original microstructure of Q370qE bridge steel. This paper lays the theoretical foundation for studying the DRX behavior of Q370qE bridge steel.

关键词： Dynamic recrystallization Materials characterization Hot deformation DRX volume fraction model

Extended-state-observer-based robust torsional vibration suppression for rolling mill main drive system with input saturation

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Journal of Iron and Steel Research International 2023年第5期30卷 985-993页

作者： Jia-qiang Chen Shu-zong Chen Chang-chun Hua Cheng Jia Cheng Qian Institute of Electrical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina National Engineering Research Center for Equipment and Technology of cold Strip rolling Yanshan UniversityQinhuangdao 066004HebeiChina

A robust torsional vibration suppression strategy is proposed for the main drive system of the rolling mill subject to uncertainties,disturbances and input *** given model information incorporated into observer design,an extended state observer that relies only on roller speed measurements is developed to estimate the system states and lumped uncertainties of the rolling mill main drive *** handle the motor torque saturation,an auxiliary signal system with the same order as the plant is *** error between the control input and plant input is taken as the input of the constructed auxiliary system,and a number of signals are generated to compensate for the effect of the motor torque ***,a robust output feedback controller is introduced to obtain better transient and steady-state performance of the rolling mill main drive system and the stability of the closed-loop system is strictly proved via Lyapunov ***,comparative simulations are performed to verify the effectiveness and superiority of the proposed control strategy.

关键词： rolling mill Main drive system Vibration suppression Extended state observer Input saturation

Microstructural characteristics of as-forged and β-air-cooled Zr-2.5Nb alloy

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Transactions of Nonferrous Metals Society of China 2018年第7期28卷 1321-1328页

作者： Lin-jiang CHAI Ke CHEN Shu-yan WANG Ji-ying XIA Ting-ting WANG Zhi-nan YANG College of Materials Science and Engineering Chongqing University of TechnologyChongqing 400054China National Engineering Research Center for Equipment and Technology of cold Strip rolling Yanshan UniversityQinhuangdao 066004China

Multiple characterization and analysis techniques including electron backscatter diffraction（EBSD）, electron channeling contrast（ECC） imaging, transmission electron microscopy（TEM） and microhardness test were jointly employed to investigate microstructural characteristics such as local composition, morphology, grain boundary characteristics and interphase orientation relationship of a forged Zr-2.5Nb alloy before and after β-air-cooling. Results show that the as-forged specimen is composed of equiaxed and lamellar α grains and continuous net-like β-Zr films. After the β-air-cooling, the microstructure of the specimen is featured by basket-weave Widmanst？tten structure, in which the inter-α-plate second phases are nanoscale β-Zr. Analyses for crystallographic orientations reveal that the Burgers relationship has been strictly followed during the β→α cooling. Compared to the as-forged specimen, the hardness of the β-air-cooled specimen is higher, which could be attributed to the decreased structural sizes of both α and β phases, and the increased fraction of high angle boundaries as well.

关键词： Zr alloy phase transformation microstructure crystallographic orientation

Roll profile electromagnetic control characteristics under roll heterogeneity

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Journal of Iron and Steel Research International 2022年第12期29卷 1927-1938页

作者： Ting-song Yang Yu-hang Bai Yang Hai Qi-fa Chen Feng-shan Du National Engineering Research Center for Equipment and Technology of cold Strip rolling Yanshan UniversityQinhuangdao 066004HebeiChina College of Mechanical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

The electromagnetic control roll(ECR)and electromagnetic stick(ES)are the core elements and the main driving parts of roll profile electromagnetic control technology(RPECT).To prolong the service life,it is necessary to treat ECR and ES *** to the heterogeneous characteristics of surface treatments,the roll profile electromagnetic control characteristics were analyzed for different *** electromagnetic-thermal-force coupled axisymmetric finite element model was built to explore the differences in performance as a result of several treatment strategies,and the model was verified by experimental results measured with a roll profile electromagnetic control experimental *** model was used to analyze the influence of the heterogeneity of ECR inner hole and ES on the roll crown,the roll profile,the average contact pressure,and the stress state during RPECT *** results indicate that the heterogeneous layer at ECR inner hole has a restrictive effect on RPECT and that the heterogeneous layer of ES can enhance the profile control ability of RPECT.A reasonable configuration scheme between the heterogeneity of ECR inner hole and the ES can increase the life of ECR and maintain the control ability of RPECT.

关键词： Electromagnetic control roll Heterogeneous treatment Roll crown Roll profile electromagnetic control technology Electromagnetic stick

An Algorithm to Analyze Electron Backscatter Diffraction Data for Grain Reconstruction:from Methodology to Application

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Acta Metallurgica Sinica(English Letters) 2016年第5期29卷 491-499页

作者： Xue-Hao Zheng Hong-Wang Zhang Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences National Engineering Research Center for Equipment and Technology of cold Strip rolling College of Mechanical Engineering Yanshan University

An algorithm for grain reconstruction based on electron backscatter diffraction data was proposed in this paper. This algorithm can well record the original data arrangement when an external file for the reconstructed grain（s） was exported for further post-processing. Assisted by an in-house MATLAB program, grain reconstruction, lattice rotations, orientation spreads, and slip system analysis can be performed. The validity of this algorithm has been successfully tested by polycrystalline Ni before and after channel die compression.

关键词： Grain reconstruction Algorithm Electron backscatter diffraction Deformation Nickle

Constitutive Model of Warm Deformation Behavior of Medium Carbon Steel

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Journal of Iron and Steel Research International 2016年第9期23卷 940-948页

作者： Hong-bin LI Yun-li FENG Tao YAN En-lin YU National Engineering Research Center for Equipment and Technology of cold Strip rolling Yanshan University College of Metallurgy and Energy North China University of Science and Technology Equipment Manufacturing College Hebei University of Engineering

The compressive behaviors of medium carbon steel specimens were investigated over a wide range of tem- peratures and strain rates using a Gleeble-3500 thermo-simulation machine. The results show that the flow stress in- creased with strain at first, and then gradually decreased after reaching a peak value. The flow stress softening rate at a high strain rate was larger than that at a low strain rate. The effects of deformation heating and friction on flow stress were analyzed. A new friction correction method, wherein the effect of strain on frictional coefficient was con- sidered, was established here. The stresses revised by the new method deviated from the measured stresses with in- creasing strain. Meanwhile, the apparent frictional coefficient variation law with strain was obtained. The frictional coefficient increased as the strain increased and then slightly decreased after maintaining a constant value. The stress was corrected by considering deformation heating. The accuracy of the temperature correction method was verified using a special experiment. The results of the verification experiment show that the temperature correction method exhibited a good accuracy in calculating the variation of stress caused by deformation heating. A constitutive model considering strain was proposed here to describe the deformation behaviors. Compared with experimental data, the modified constitutive model exhibited a good accuracy as to constitutive correlation.

关键词： friction correction temperature correction deformation heating flow stress constitutive model