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2012年, 第19卷, 第9期 刊出日期:2012-09-15
  

  • 全选
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    综述
  • ZHANG Fu-ming,MAO Qing-wu,MEI Cong-hua,LI Xin,HU Zu-rui
    中国钢铁期刊网. 2012, 19(9): 1-7.
    摘要 ( )   可视化   收藏
    In Shougang Jingtang 5500 m3 huge blast furnace (BF) design, dome combustion hot blast stove (DCHBS) technology is developed. DCHBS process is optimized and integrated, and reasonable hot blast stove (HBS) technical parameters are determined. Mathematic model is established and adopted by computational fluid dynamics (CFD). The transmission theory is studied for hot blast stove combustion and gas flow, and distribution results of HBS velocity field, CO density field and temperature field are achieved. Physical test model and hot trail unit are established, and the numeral calculation result is verified through test and investigation. 3-D simulation design is adopted. HBS process flow and process layout are optimized and designed. Combustion air two-stage high temperature preheating technology is designed and developed. Two sets of small size DCHBSs are adopted to preheat the combustion air to 520-600 ℃. With the precondition of BF gas combustion, the hot blast stove dome temperature can exceed 1420 ℃. According to DCHBS technical features, reasonable refractory structure is designed. Effective technical measures are adopted to prevent hot blast stove shell intercrystalline stress corrosion. Hot blast stove hot pipe and lining system are optimized and designed. After blowing in, the blast temperature keeps increasing, and the monthly average blast temperature reaches 1300 ℃ when burning single BF gas.
  • 工艺
  • ZHANG Hua-wei,LIU Li-zhong,HU Ping,LIU Xiang-hua
    中国钢铁期刊网. 2012, 19(9): 8-12.
    摘要 ( )   可视化   收藏
    In order to grasp the springback rule of TRB (tailor rolled blank) parts after forming, the springback behavior of TRB was investigated by integrating such three means as theoretical research, numerical simulation and stamping experiments. Fundamental theories of springback were analyzed. The stamping and springback processes of annealed 1.2/2.0 mm TRB, 1.2 mm and 2.0 mm plates for U-channel were simulated, and the simulation results were compared with the experiments. The results indicate that the springback of TRB falls in between those of the 1.2 mm and 2.0 mm plates. It is desirable for the TRB U-channel to have die clearance of 1.1 times maximum blank thickness and friction coefficient of about 0.12, and longer thickness transition zone is preferable. The simulation data demonstrate reasonably good agreement with the experiments.
  • LAN Rong-zong,,WANG Jing-song,HAN Yi-hua,SHE Xue-feng,WANG Lin-tao,XUE Qing-guo
    中国钢铁期刊网. 2012, 19(9): 13-19.
    摘要 ( )   可视化   收藏
    In order to explore the behavior laws of sinter reduction in TGR-OBF (top gas recycling-oxygen blast furnace), reduction experiments of sinter have been conducted by thermal balance mass loss method with different atmospheres, temperatures and volume flows. The changes of RI (reduction degree of Fe2O3), RI′ (reduction rate of Fe2O3) and r (reduction degree of FeO) have been examined. The results show that the reduction of sinter was significantly improved under TGR-OBF atmosphere, and the RI and r were measured up to 98.2% and 97.8% at 900 ℃ respectively. With increasing of the reduction temperature, the reduction of sinter speeded up greatly, and the reduction time-duration shortened from 117 min at 900 ℃ to 63 min at 1100 ℃. Moreover, the reduction of sinter enhanced with increasing of the reductive gas flow. When the flow increased from 10 to 15 L/min, the initial reduction rate of sinter increased from 2.47%/min to 3.73%/min. While increasing H2 and CO contents in the reductive atmosphere, the reduction of sinter was promoted. Besides, H2 influenced more evidently than CO to the reduction of sinter, especially in the later stage of the reduction process, for instance, the reduction of wustite will be improved enormously when increasing the H2 content in the reductive atmosphere.
  • SONG Chun-yue,HU Kai-lin,LI Ping
    中国钢铁期刊网. 2012, 19(9): 20-28.
    摘要 ( )   可视化   收藏
    A new scheduling model for the bulk ore blending process in iron-making industry is presented, by converting the process into an assembly flow shop scheduling problem with sequence-depended setup time and limited intermediate buffer, and it facilitates the scheduling optimization for this process. To find out the optimal solution of the scheduling problem, an improved genetic algorithm hybridized with problem knowledge-based heuristics is also proposed, which provides high-quality initial solutions and fast searching speed. The efficiency of the algorithm is verified by the computational experiments.
  • YU Yu-zhen,,REN Xin-yi,DU Feng-shan,SHI Jun-jie
    中国钢铁期刊网. 2012, 19(9): 29-35.
    摘要 ( )   可视化   收藏
    In view of characteristics of particle swarm optimization (PSO) algorithm of fast convergence but easily falling into local optimum value, a novel improved particle swarm optimization algorithm is put forward, and it is applicable to identify parameters of hydraulic pressure system model in strip rolling process. In order to maintain population diversity and enhance global optimization capability, the algorithm is firstly improved by means of decreasing its inertia weight linearly from the maximum to the minimum and then combined with chaotic characteristics of ergodicity, randomness and sensitivity to initial value. When the improved algorithm is used to identify parameters of hydraulic pressure system, the comparison of simulation curves and measured curves indicates that the identification results are reliable and close to actual situation. A new method was provided for hydraulic AGC system model identification.
  • LI Hai-feng,LUO Zhi-guo,ZOU Zong-shu,SUN Jun-jie,HAN Li-hao,DI Zhan-xia
    中国钢铁期刊网. 2012, 19(9): 36-42.
    摘要 ( )   可视化   收藏
    COREX process is one of the earliest industrialized smelting reduction ironmaking technology. A numerical simulation model based on discrete element method (DEM) has been developed to analyze the burden distribution in the melter gasifier of COREX process. The DEM considering the collisions between particles can directly reproduce the charging process. The burden trajectory, the location and the burden surface profile are analyzed in melter gasifier with a mixing charging of coal and direct reduction iron (DRI) at the same time. Considering the porosity of packed bed has an important effect on the gas flow distribution of melter gasifier, a method to calculate porosity has been proposed. The distribution of DRI and coal and the porosity in the radial direction are given under different charging patterns, which is necessary to judge the gas flow distribution and provide base data for further researching the melter gasifier for the next work in the future. The research results can be used to guide the operation of adjusting charging and provide important basis for optimizing the charging patterns in order to obtain the reasonable gas distribution.
  • WANG Xiao-dong,,LI Fei,JIANG Zheng-yi
    中国钢铁期刊网. 2012, 19(9): 43-51.
    摘要 ( )   可视化   收藏
    Non-uniformity of temperature distribution across strip width direction is the ultimate reason why the flatness defect occurs on the strip after cooling process although the strip is flat at the exit of finishing mill. One thermal, microstructural and mechanical coupling analysis model for predicting flatness change of steel strip during the run-out table cooling process was established using ABAQUS finite element software. K Esaka phase transformation kinetics model was employed to calculate the phase transformation, and coupled with temperature calculation using the user subroutine program HETVAL. Elasto-plasticity constitutive equations of steel material, in which conventional elastic and plastic strains, thermal strain, phase transformation strain and transformation induced plastic strain were considered, were derived and programmed in the user subroutine program UMAT. The conclusion that flatness of steel strip will develop to edge wave defect under the functions of the differential thermal and microstructural behaviors across strip width during the run-out table cooling procedure was acquired through the analysis results of this model. Calculation results of this analysis model agree well with the actual measurements and observation.
  • 材料
  • MA Li-feng,,HUANG Qing-xue,HUANG Zhi-quan,CHU Zhi-bing,TIAN Ya-qin
    中国钢铁期刊网. 2012, 19(9): 52-61.
    摘要 ( )   可视化   收藏
    The purpose aims to improve the plate shearing section quality and metal yield by means of optimal blade clearance adjustment model of rolling-cut shear and accurate calculation of the maximum shearing force, as well as for the system optimization design, structure optimization design to provide important basis. A 3500 mm rolling shear of a large stainless steel factory was taken as the test object, and the blade clearance under different influence factors of the clearance value and the shearing section were tested. The optimized production accumulated data regression analysis and the rolling shear process of stainless steel shear test. The test results show that the optimal blade clearance adjustment module is a comprehensive function, which include steel plate thickness, material, temperature and shear plate volume. The shear stress at starting stage with the relative penetration depth increases affected by the above factors, and the fracture peak decreases rapidly after being cut into the roll phase constant.
  • ZHU Na-qiong,LU Li,HE Yan-lin,LI Lin,LU Xiao-gang
    中国钢铁期刊网. 2012, 19(9): 62-67.
    摘要 ( )   可视化   收藏
    Coarsening of M23C6 precipitates in an Fe-12.4Cr-0.13C ternary alloy has been investigated ageing at 780 ℃ up to 200 h. Evolution of M23C6 carbides at different ageing times was determined experimentally using transmission electron microscopy. Particle size distribution was obtained with different measuring methods. Simulations of coarsening of M23C6 precipitates were carried out using computational thermodynamics and kinetics. Results showed low coarsening rates for M23C6 precipitates in the Fe-Cr-C ternary alloy. Interfacial energy of M23C6/ferrite interface is between 0.1 and 0.3 J·m-2 for the coarsening of M23C6 ageing at 780 ℃.
  • DING Hua,,LI Hua-ying,DING Hao,QIU Chun-lin,TANG Zheng-you
    中国钢铁期刊网. 2012, 19(9): 68-72.
    摘要 ( )   可视化   收藏
    Two steels without and with Nb addition were chosen to investigate the effects of Nb on the microstructures and the mechanical properties of Fe-Mn-Al-Si steels. The results revealed that Nb refined the grains markedly and both TRIP and TWIP effects occurred during deformation process. The Nb containing steel possesses higher yield strength and much lower tensile strength, the latter being explained by the suppression of TRIP effect due to the increase of stacking fault energy. This indicates grain refining is secondary for strengthening of steels when TRIP or TWIP effect exists during the deformation of low carbon and high Mn steels.
  • ZHANG Kun,TANG Di,WU Hui-bin
    中国钢铁期刊网. 2012, 19(9): 73-78.
    摘要 ( )   可视化   收藏
    The alloy was reheated to 580 ℃ for tempering at rates of 2, 5, 10, 20, and 40 ℃/s, respectively, after quenching. The amount, distribution, and stability of reversed austenite were investigated by X-ray diffraction (XRD) and electron back scatter diffraction (EBSD). The microstructure and cryogenic impact energy were studied by scanning electron microscope (SEM), transmission electron microscope (TEM) and Charpy V-notch (CVN) tests. The results showed that when the sample was heated at 10 ℃/s, the volume fraction of reversed austenite exhibited maximum of 8%; the reversed austenite was uniform along all kinds of boundaries; the reversed austenite contained higher concentration of carbon which enabled it to be more stable. The cryogenic toughness of the alloy was greatly improved when heated at 10 ℃/s, as the fracture surface observation showed that it mainly fractured in ductile rupture mode, which was consistent with the results of cryogenic impact energy.