超轻钢制汽车工程使轿车车门重量减轻42%

由世界一些大型钢铁公司参加的ＵＬＳＡ (超轻钢制汽车 )工程 ,通过框架设计已使轿车车门重量减轻 42 %。ＵＬＳＡ的目的是全面减轻轿车重量 ,以便提高燃料效率及安全性 ,同时减少排放物。最新的发展是用高强度钢制造的 4根小型材替换传统车门框架。2根液压成型的强度等级为2 80ＭＰａ的高强度钢管制造车门的销及枢轴 ,另外 2根强度等级为80 0ＭＰａ的直管制造沿车身方向延伸的车门的上下框架。激光焊接的1 2、 1 0ｍｍ厚、强度为 140ＭＰａ低碳钢薄板用作车门内部件。这种车门框架的设计不包含车窗框架 ,该结构比含车窗框架的车门重量轻42 …     

汽车覆盖件包合模结构探讨

汽车覆盖件包合模结构探讨保定汽车制造厂（河北保定０７１０５１）国军李云峰汽车车身制造过程中，对内、外覆盖件进行叠压包边的模具称为包合模或包边模。在轿车和皮卡车生产中，需要包合的零部件为“五门一机盖”，即左、右前侧车门和左、右后侧车门、四门轿车的旅行箱...     

凸轮式侧冲模

介绍一种凸轮式侧冲模的结构形式。这种侧冲模在奥地利斯太尔汽车制造厂用来冲汽车车门内盖板侧壁孔。对于冲汽车车身零件侧壁的单个孔来说,这种结构比楔式冲模体积小且制造简便。     

白车身装焊过程的可视化工艺信息模型

针对轿车白车身装焊生产的工艺设计和管理问题，提出采用树状模型与关系模型来描述车身装焊工艺信息的混合建模方法，并在此数据模型基础上借助人机交互式三维仿真平台，建立了白车身虚拟装焊可视化工艺信息模型。对某轿车车门的装焊工艺的可通过性进行了仿真分析。结果表明，该模型能够直观完整地表达装焊过程的各种工艺信息，可为轿车车身的结构设计、装焊工艺的分析与设计、工艺信息的管理、生产质量控制以及轿车个性化市场销售等提供帮助。     

鞍钢汽车板开始用于宝马车

据钢铁行业信息，鞍山钢铁集团新轧一蒂森克虏伯镀锌钢板有限公司开始为沈阳宝马及马自达6生产高等级汽车外板，包括IF钢、烘烤硬化钢等5个规格的产品，分别用于轿车车顶面板、车身侧面板、车门面板及车身后面板。     

美洲虎和沃尔沃轿车公司开发新镁合金部件

福特汽车公司的2个分公司，即英格兰的美洲虎和瑞典的沃尔沃正在开发新镁合金轿车部件，多数有望获准由澳大利亚于2004年开始生产。澳大利亚镁业公司(AMC)已为美洲虎和沃尔沃轿车公司的工程技术人员配置了开发场所。福特公司的消息灵通人士透露，开发部件包括一些大型主体件和结构件，如车门、升降门支架、柱及仪器面板支撑框。 据报道，开发的焦点集中在如何获得高熔凝结密度的模压铸件技术、减小车振动、降低噪声和车重，同时提高生产率和生产工具寿命，降低相对高的镁部件成本也是不可忽略的问题。 在AMC的协助下，英格兰和瑞典汽车厂…     

汽车车身零件的压合装配模

<正> 将两个或两个以上的车身零件装配压合成一体的模具称为压合装配模。在汽车和轿车车身零件上采用压合装配模的有车门内外板、发动机罩内外板和行李箱盖内外板。 按压合工序的性质是属于翻边,修过边     

基于灵敏度分析的车门尺寸和拓扑优化

为了改善微型车X30的车门在使用过程中振动过大这一问题,利用Hypermesh建立该车车门的有限元模型,并对其进行模态分析。分析结果发现车门的一阶频率偏低,容易与白车身一阶弯曲频率发生共振。因此,基于灵敏度分析方法结合尺寸优化和拓扑优化方法对车门进行以提升车门一阶模态频率为目标的优化设计。首先,对车门各零部件进行质量灵敏度和一阶模态频率灵敏度分析,并定义相对灵敏度值;然后,根据相对灵敏度值结果选择合适的设计变量进行部件厚度的尺寸优化设计;最后,基于变密度法对相对灵敏值最大的部件进行拓扑优化,根据优化结果对该部件有限元模型进行修改。结果表明,在车门质量减少4.5%的情况下,车门一阶模态频率提高8.9%,有效地改善了车门的振动情况。     

激光钎焊与激光熔焊在白车身制造中的应用

随着激光技术的进步,应用范围越来越广,目前激光钎焊与激光熔焊主要应用在白车身制造中的车门、行李箱盖、车身顶篷、侧围、侧围流水槽等部件,本研究主要从设备组成、工艺、质量控制等方面,介绍当前汽车行业激光钎焊、激光熔焊方面的应用。     

轿车车身点焊装配误差分析模型的建立与研究

时是轿车车身装配的主要形式,完成９０％以上的轿车车身零件装配工作量,通过考察车身点焊装配特点,建立了一个焊点焊接的电极与零件点焊装配１／２轴对称模型并利用有限元法对点焊过程进行了电、热及结构领域的数值分析。在假设零件之间不存在装配间隙的前提下,讨论卫点焊装配的变形,为进一步建立研究车身装配的多点点焊过程点焊过程模型奠定了建模基础 。     

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.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

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.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.