异型阴极电解槽焙烧方法的探索研究

通过对阴极电解槽的燃气焙烧法、以阳极炭块作为填充物的焦粒焙烧法以及以电解质块作为填充物的异型阴极焦粒焙烧方法的分析研究,根据试验数据和运行状况,认为以电解质块作为填充物的方法在生产实际中运用能够成功解决异型阴极电解槽其它焙烧方法存在的弊端.     

大修槽焦粒焙烧的实践和分析

铝电解槽大修后采用焦粒焙烧,具有阳极和阴极中电流分布均匀,阴极温度均衡上升,槽温高,有利于延长电解槽寿命等优点。本文总结了电解槽大修后采用焦粒焙烧的实践经验。取得了节能、提高经济效益的良好结果。     

铝电解槽燃气预热过程中阴极热应力场的数值模拟

本文采用有限元分析软件ANSYS建立了160kA铝电解槽半槽热应力场模型,并对铝电解槽燃气预热过程中的温度、位移与热应力分布进行了数值模拟研究.研究结果表明:燃气预热法能满足铝电解槽焙烧启动的工艺要求:阴极炭块两侧的位移呈对称分布,X方向、Y方向和Z方向上位移较大的区域分别位于炭块边部、中部及DE端炭块 附近.三个方向中,Y方向的位移最大,最大值为10.83mm;热应力集中的区域位于中央炭块下的阴极炭块与钢棒接触处,最大热应力为91.2MPa;数值模拟结果为铝电解槽的合理设计提供了理论依据.     

阳极焙烧炉焙烧阴极炭块的探索

根据铝用阴极焙烧升温工艺要求,研制并实施了阳极焙烧炉焙烧阴极的系统试验方案,包括过渡曲线、焙烧曲线、负压控制等内容,试烧后的42块阴极炭块外观质量及理化指标合格率均为100%,为下一步利用阳极焙烧炉大批量生产阴极炭块奠定了技术基础。     

铝用炭素市场分析

铝用炭素主要分为炭素阴极和炭素阳极两大类。铝电解槽阳极有阳极糊和预焙阳极之分,前者用于自焙阳极电解槽,后者用于预焙阳极电解槽。阴极炭块又分为无烟煤炭块、半石墨质炭块、石墨质炭块和石墨化炭块。     

5kA级惰性阳极铝电解槽热平衡仿真

使用有限元软件Ansys仿真计算5 kA级惰性阳极铝电解槽的槽膛内形及热平衡情况.结果表明:过热度和侧部炭块类型对槽膛内形产生显著影响,过热度增加10 ℃,槽帮厚度减少约50%,伸腿宽度减少约30%;侧部炭块散热性越好,槽帮厚度和伸腿宽度越大;半石墨质类型的侧部炭块能够在保证形成满足要求的槽膛内形时降低热量损失,建议采用这类侧部炭块;采取一定措施后,采用半石墨质阴极和石墨化阴极的电解槽均能实现热平衡,石墨化阴极电解槽比普通阴极电解槽所需能量约多9%,但在热平衡时阴极底部等温线分布更合理.     

大型铝电解槽72小时焙烧启动实践

介绍了420k A大型铝电解槽焦粒焙烧干法启动工艺,通过在角部使用焦粒与石墨碎的混合物,采用残极作为角部极,合理控制焙烧启动工艺,获得了均匀的电流分布和温度分布,不仅使焙烧时间缩短为72小时,而且槽壳变形小。     

新型阴极钢棒对铝电解槽电热场的影响

采用数值仿真的方法对应用一种可减小铝液中水平电流的新型阴极钢棒的420 kA级铝电解槽进行三维计算,分析这种新型阴极钢棒对铝液中水平电流、槽电压以及电解槽温度分布的影响。结果表明:新型阴极钢棒可有效地减小铝液中X方向的水平电流;新型阴极钢棒中绝缘材料的加入在一定程度上增大了槽电压;当钢棒和钢棒糊接触不是很好时,新型阴极钢棒电解槽比传统阴极钢棒电解槽更容易出现阴极炭块和钢棒连接区域温度过高的情况。该计算结果可为铝电解槽在应用此种新型阴极钢棒后所获得的节能效果以及个别槽在运行过程中出现的问题提供理论依据。     

高温烟气焙烧铝电解预焙槽的工业应用

针对目前国内外铝电解槽焙烧启动方法的特点，提出用燃料燃烧产生的高温烟气来焙烧启动预焙阳极铝电解槽。并在160kA系列和75kA系列预焙槽上进行了工业试验，结果表明烟气焙烧技术易于实现电解槽焙烧操作的自动化，使阴极温度缓慢均匀上升，阴极表面温度均匀，不但能方便地按要求焙烧好阴极炉底．而且能使侧部札糊取得很好的焙烧效果，氧化烧损少．是较理想的铝电解槽焙烧启动方法。     

应用新技术降低240kA铝电解槽电耗的实践

在240kA铝电解槽大修时应用了高导电性阴极钢棒、内保温、30%石墨阴极炭块、冷捣糊及优化阴极组装工艺等技术,经过了900多天的安全稳定运行,生产实践表明,优化的240kA铝电解槽内衬结构成功解决了该类电解槽低电压下能量不平衡的问题,实现了电解槽低电压下稳定运行,达到了高效节能的目的。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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