感应加热在锡焊上的应用

感应加热具有加热速度快、效率高、易实现自动化的特点，万其在锡焊方面。由于焊锡熔点低，效果更加明显。在感应钎焊中，感应卷的设计是关键。     

领先的感应加热热处理设备

在过去的二十年中，感应处理的应用已越来越广泛。其主要原因之一是由于对工件进行热处理时，感应加人有只对需要轴热区域精确地进行集中、快速加热这一能力，从而缩短了处理时间，因此在满足技术要求的同时，提高了生产率。感应加热与大部分其它用于热处理的热源相比，提高了能源效率，同时对环境无害。本文是关于感应加热在现代金属热处理领域所取得综述，具体涉及齿轮感应淬火、在线回火、凸轮轴承面淬火、品质保证、过程控制／临     

国外汽车工业感应热处理技术的发展与应用

感应热处理在国外应用十分广泛。感应热处理零件所占比重在逐渐扩大。感应热处理设备制造水平越来越高，品种越来越多，感应热处理新工艺、新材料不断涌现。1低淬钢种类、特点1．五种类问）低碳低淬钢，其含碳量为0．2％，适用于汽车车架。（2）中碳低淬钢，含碳量为0．4％～0．6％，适用于轴类、齿轮和钢板弹簧。（）高碳低淬钢，含碳量为0·95％～l·05％，适用于轴承。l·2低淬钢特点（l）钢中合金含量低，因此淬透性低；（2）本质细晶粒，感应加热淬火，晶粒度可达11～12级；（3）淬火时需要很大的临界冷速，表面冷速8000～30000℃／S…     

0.5吨铸铁用无芯工频感应电炉炉衬烘烤与烧结

我厂使用0.5t无芯工频感应电炉,在没有调压装置情况下,我们采用“空炉断续通电、缓慢升温”烘烤炉衬。实践说明只要工艺制订合理。仍然可以达到预期的目的。下表是我厂对0.5t无芯工频感应电炉炉衬烘烤与烧结断续通电的时限工艺: 一、炉衬捣筑和炉盖筑砌好后,立即取出压铁,清除钢坩埚内的石英砂和其它杂物。然后将电路、冷却水路检查后进行试运行,若无问题,方可通电烘炉。200℃以前要求断续通电、缓慢     

感应熔炼电炉的技术规格及炉型选择

以实践经验为基础,对感应熔炼电炉的炉膛容量、熔炼时间、比功率、谐振频率、补偿电容等主要技术规格及其相互间的关系,试用数学的方式作出表述;对工频感应电炉、中频感应电炉、中频变频感应电炉等主要炉型,试用基本原理图作出解析,以期对感应熔炼电炉的主要技术规格及其炉型的选择提供参考.     

欧洲的感应淬火和感应加热

一、引言和历史背景欧洲感应淬火的发展是建立在特有的技术和经济条件上的,劳动力就是一个经济条件。本世纪60年代,由于缺少劳动力,约有300万外籍工人进入联邦德国;其他欧洲国家也雇佣外籍工人。此外,作为感应淬火设备主要用户的汽车工业,受到的冲击并不太     

轧机用感应加热器的国产化

我公司从英国进口的预热、加热两套感应加热器用于变截面弹簧轧制前加热的。感应器为浇铸全封闭悬臂式结构,经多年使用后发现故障率高,维修费用大,周期长,直接影响变截面弹簧生产。为此我们自行研制了新的感应器,满足了工艺要求,现已推广应用。１感应加热技术要求所...     

高频感应电热设备常见故障诊断及处理

用于工业热处理或冶金熔炼的高频感应电热设备，常因工作在高频高压状态以及大电流动态变量的过渡过程中，因而这类设备在实际应用中不仅对使用条件的要求较高（例如供水供电的质量要求以及环境的温度与湿度要求等），而且对设备运行中的过渡过程的适时比例控制要求也较严格。倘若设备在使用过程中，或因使用条件的不满足，或因操作比例失调以及维修保养不当等原因影响，极易引发设备的各类故障。事实表明，这些故障的易发部位及故障维修的难点大都在设备的高频与高压系统电路内。为提高诊断速度与维修效率，笔者根据多年来的使用维修经验，…     

导磁体在汽车零件感应加热中的应用技术

本文简单介绍了导磁体工作的基本原理，并给出在汽车零件大规模生产中所积累的导磁体应用的一些经验，以阐明如何更有效地使用导磁体。     

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。     

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).     

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.     

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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