2004年, 第11卷, 第6期　刊出日期：2004-11-25

  

• 全选
  |

• Select
  Transient Temperature Analysis for Industrial AC Arc Furnace Bottom

  Ünal Çamdali, Murat Tunç

  钢铁研究学报（英文版）. 2004, 11(6): 1-4.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  Heat losses from the furnaces depend on the design and size. The surface heat loss from the bottom of an industrial AC electric arc furnace (EAF) possesses an important fraction of overall losses. So in this study the transient temperature variation at the bottom of the EAF was investigated. The transient temperature analysis was carried out using MATLAB computer program. T=T(r, t) for different bottom lining layers was depicted.
• Select
  Fundamental of Inclusion Removal from Molten Steel by Rising Bubble

  WANG Li-tao, ZHANG Qiao-ying, LI Zheng-bang, XUE Zheng-liang

  钢铁研究学报（英文版）. 2004, 11(6): 5-9.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  The mechanism of inclusion removal by attachment to rising bubble was analyzed, and the movement behavior of inclusion, the mechanism of bubbles/inclusion interaction, collision probability and adhesion probability were discussed. A mathematical model of inclusion removal from molten steel by attachment to fine bubble was developed. The results of theoretical analysis and mathematical model showed that the optimum bubble diameter for inclusion removal is 1 to 2 mm. A new method that argon is injected into the shroud from ladle to tundish during continuous casting has been proposed to produce fine bubble. It provides theoretical guides for production of super clean steel.
• Select
  Surface Roughness of Flux Film in Continuous Casting Mold

  JIANG Mao-fa, ZHU Chuan-yun, HAN Wen-dian

  钢铁研究学报（英文版）. 2004, 11(6): 10-13.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  The corundum plates with a groove were used to freeze molten flux into solid slice to simulate the flux film formed in continuous casting mold, and thereby to study the formation mechanism of flux film with different surface roughness. The effect of some factors on the surface roughness of flux film, such as reheating rate, cooling rate, flux film thickness and crystallization ratio, was discussed.
• Select
  Heat Transfer Characteristic of Molten Pool for Twin-Roll Strip Casting

  XING Chang-hu, ZHAI Qi-jie

  钢铁研究学报（英文版）. 2004, 11(6): 14-19.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  Body-fitted coordinate transformation equation was deduced and used to generate the body-fitted grids of molten pool for twin-roll strip casting. The orthogonality of the grids on the boundary was modified by adjusting source item. The energy equation and the boundary conditions were transformed from physical space to computational space. The velocity field model proposed by Hirohiko Takuda was used to calculate the temperature field of molten steel, and the influence of technical factors was also discussed.
• Select
  Effect of SEN Parameters on 3D Flow Field in Mould of Beam Blank Continuous Caster

  YANG Jian-wei, DU Yan-ping, SHI Rong, CUI Xiao-chao, LIU Cai

  钢铁研究学报（英文版）. 2004, 11(6): 20-24.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  According to turbulent theory and characteristics of beam blank continuous casting, a 3D flow field model for beam blank mould was established with calculation program to analyze the change of eddy current center depth and turbulent kinetic energy distribution on meniscus for different SEN designs. The result showed that the outlet inclination of +15° should be adopted, which promotes the floating up of slag inclusions and the purification of molten steel; when the outlet angle is 120°, the flow field is more rational; the proper nozzle depth is 200 mm. The model provides a fundamental basis for design of SEN and determination of immersion depth.
• Select
  Thickness and Shape Synthetical Adjustment for DC Mill Based on Dynamic Nerve-Fuzzy Control

  JIA Chun-yu, WANG Ying-rui, ZHOU Hui-feng

  钢铁研究学报（英文版）. 2004, 11(6): 25-29.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  Due to the complexity of thickness and shape synthetical adjustment system and the difficulties to build a mathematical model, a thickness and shape synthetical adjustment scheme on DC mill based on dynamic nerve-fuzzy control was put forward, and a self-organizing fuzzy control model was established. The structure of the network can be optimized dynamically. In the course of studying, the network can automatically adjust its structure based on the specific questions and make its structure the optimal. The input and output of the network are fuzzy sets, and the trained network can complete the composite relation, the fuzzy inference. For decreasing the off-line training time of BP network, the fuzzy sets are encoded. The simulation results indicate that the self-organizing fuzzy control based on dynamic neural network is better than traditional decoupling PID control.
• Select
  Self-Learning Algorithm for Coiling Temperature Controlling

  WANG Jun, WANG Guo-dong, LIU Xiang-hua, ZHANG Dian-hua

  钢铁研究学报（英文版）. 2004, 11(6): 30-32.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  In order to establish a mathematical model for strip laminar cooling, the self-learning algorithm was introduced with the level learning for obvious heat flux fluctuation and the pattern learning for small heat flux fluctuation. The short self-learning calculation steps of water cooling and air cooling, and the long self-learning formula were given with some results.
• Select
  Modeling for Formation of Proeutectoid Ferrite in Steel during Continuous Cooling

  YE Jian-song, CHANG Hong-bing, T Y Hsu

  钢铁研究学报（英文版）. 2004, 11(6): 33-36.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  A novel model of the evolution of microstructure during continuous cooling with the formation of proeutectoid ferrite in steel was proposed from a Voronoi construction for the austenite grains, based on the Rappaz's integral nucleation model and the assumption that the ferrite nucleates at the edges of the original austenite grains and the successive growth of the ferrite grain is radial. The model can be used to calculate the fraction of ferrite as a function of time or temperature during continuous cooling, and to determine the microstructure of ferrite. The calculated results are in agreement with experimental results investigated in 0.38C-0.28Si-0.55Mn-0.92Cr-0.20Mo steel under continuous cooling using a Gleeble 1500 thermomechanical simulator.
• Select
  Effects of Pulse Current on Solidification Structure of Austenitic Stainless Steel

  FAN Jin-hui, CHEN Yu, LI Ren-xing, ZHAI Qi-jie

  钢铁研究学报（英文版）. 2004, 11(6): 37-39.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  The 1Cr18Ni9Ti specimens were treated respectively with pulse current under 520 V and 2 600 V during solidification and the solidification structure was observed. The results showed that pulse current can refine solidification grains, cut primary dentrities remarkably and reduce second dentritic arm spacing. The mechanism and effect are changed with operation parameters.
• Select
  Effects of Holding Temperature for Austempering on Mechanical Properties of Si-Mn TRIP Steel

  LI Zhuang, WU Di

  钢铁研究学报（英文版）. 2004, 11(6): 40-44.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  A new type of high strength steel containing a significant amount of stable retained austenite was obtained by austempering immediately after intercritical annealing. This sort of low carbon steel only contains alloying elements of silicon and manganese rather than nickel and chromium. Its mechanical properties were enhanced considerably due to strain-induced martensite transformation and transformation-induced plasticity (TRIP) of retained austenite when it was strained at temperatures between M_s and M_d, because retained austenite was moderately stabilized due to carbon enrichment by austempering. Austempering was carried out at different temperatures and 400°C was found to be optimal. Tensile strength, total elongation and strength-ductility balance reached the maximum values and the product of tensile strength and total elongation exceeded 30 135 MPa % when the TRIP steel was held at 400°C and strained at 350°C.
• Select
  Morphology and Magnetic Properties of Electrodeposited Iron and Nickel Based Alloy Foils

  GUO Zhan-cheng, LIU Mei-feng, SUN Chun-wen, LIU Yu-xing, LU Wei-chang

  钢铁研究学报（英文版）. 2004, 11(6): 45-51.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  An alternative to conventional process for the preparation of soft magnetic metal foils of Fe,Fe-Ni,Fe-Co and Fe-Ni-Co by electroforming was described. The microstructure and magnetic properties were observed. The results showed that the crystal size of the iron-based alloy foil is less than 10 μm,while that of nickel-based alloy foil is about 2 μm. Moreover,the electroformed Fe-Ni foil has better magnetic properties than the conventional milled permalloy 1J79 foil.
• Select
  Transformation and Field-Induced Strains in as-Cast Ni-Mn-Ga Alloy

  ZHAO Wei-ren, LI Jian-liang, QI Yan, ZHANG Yang-huan, WANG Xin-lin, YU Yuan-jun

  钢铁研究学报（英文版）. 2004, 11(6): 52-56.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  The characteristics of the strains induced by transformation and magnetic field in as-cast Ni-Mn-Ga alloy were systematically investigated. It is found that internal stress and texture introduced during casting bring the anisotropy of temperature-induced strains. However,no anisotropy of field-induced strains is induced,and the internal stress and the texture modulate only the temperature dependence of field-induced strains. Large retardance of field-induced strains was observed,which indicates the rearrangement of martensitic variants as a competition process between the stress energy and Zeeman energy. The non-continuous field dependence of strain indicates the unstable microstructure during martensitic transformation.
• Select
  Dynamics of Gradient Bioceramic Composite Coating on Surface of Titanium Alloy by Wide-Band Laser Cladding

  LIU Qi-bin, ZOU Long-jiang, ZHU Wei-dong, LI Hai-tao, DONG Chuang

  钢铁研究学报（英文版）. 2004, 11(6): 57-62.

  摘要 ( ) PDF全文 ( )   可视化   收藏

  The gradient bioceramic coating was prepared on the surface of titanium alloy using wide-band laser cladding. The dynamics of gradient bioceramic composite coating containing hydroxyapatite (HA) prepared with mixture of CaHPO₄·2H₂O and CaCO₃ under the condition of wide-band laser was studied theoretically. The corresponding mathematical model and its numerical solution were presented. The examination experiment showed that HA bioceramic composite coatings can be obtained by appropriately choosing wide-band laser cladding parameters. The microstructure and surface morphology of HA bioceramic coating were observed by SEM and X-ray diffraction. The experimental results showed that the bioceramic coating is composed of HA,β-TCP,CaO,CaTiO₃ and TiO₂. The surface of bioceramic coating takes coral-shaped structure or short-rod piled structure,which helps osteoblast grow into bioceramic and improves the biocompatibility.