浅析激光落料线

对激光落料线的发展状况进行了介绍,对激光落料线的工作原理进行了说明,分析了激光落料线与传统冲压落料线间优劣,针对相对传统落料线效率不高问题,提出了单体效率提升、运动部件轻量化、多轴联动控制、专用CAM系统开发4种效率提升措施.     

浅谈激光落料线在汽车板上的应用

本文对开卷落料线未来发展方向之一——激光落料线作了介绍,对激光落料线与传统落料线进行对比,介绍了激光落料线的优势,对激光落料线在汽车板中的应用进行了阐述。     

冷轧生产线惰辊的改进及应用

针对冷轧带钢生产线中的惰辊经常因受乳化液侵蚀而导致惰辊轴承烧毁及辊面磨损划伤带材的问题,设计了一种能够适应乳化液喷淋环境的毛化镀硬铬惰辊。该惰辊密封效果好,辊面采用毛化镀硬铬处理,其防滑性能和耐磨性能良好。     

冷轧辊毛化技术的对比研究

系统分析了几种国内外正在使用或试验研究的冷轧辊毛化技术，并依据其加工特性，从毛化轧辊的表面粗糙度、峰值密度、形貌传递特性、环境污染及设备运行成本等方面进行了较为深入的比较研究。在分析比较的基础上，提出了冷轧辊毛化技术的研究方向及发展趋势。     

一种高速激光落料线

论述了一种高速激光落料线,该生产线配备多个激光头同时工作,对卷料金属板进行连续高速切割,制成任何所需轮廓的料片,可以实现高速动态在线加工,是集成开卷校平、激光切割、成品码垛的高效自动化生产线。     

冷轧平整后带钢“亮线”缺陷及其解决措施

针对采用抛丸毛化轧辊平整机平整后的马口铁基板上出现的批量色差亮线,分析了轧辊表面形貌及轧辊表面发生剥落的原因,提出除需保持机架内腔、工作辊和支撑辊表面洁净外,还需尽量减少抛丸次数,采用圆形或圆形与菱形混合丸料,可避免轧辊表面出现“层状翘起组织”,从而控制带钢表面的“亮线”缺陷。     

轧辊光纤激光无序毛化技术:无序毛化的应用(下篇)

在连轧机、平整机、光整机上对光纤激光无序毛化轧辊与电火花毛化轧辊的过钢量,粗糙度R_a和R_(pc)值随过钢量的变化进行了对比;同时,对光纤激光无序毛化轧辊R_a=2.0~5.0μm范围内与R_(pc)值的关联情况进行了研究。结果表明:光纤激光无序毛化轧辊适用于连轧、平整、光整等工艺,其R_(pc)值高于电火花毛化辊,且R_a与R_(pc)的关联度较弱。     

先进开卷落料线的工艺规划设计

开卷落料线是一种适用于汽车、钢板配送等行业高档外饰卷板的板材加工设备。本文通过对开卷落料线各模块功能分析,论述了开卷落料线建线中的开卷输送系统设计、主要加工设备选用、堆垛装置设计等。开卷落料线的工艺规划设计应该充分考虑铝合金板材的应用。分析结果表明,钢铝混合开卷落料线的工艺规划设计可以满足未来生产线的发展需要,同时可以大大降低企业设备投资及生产区域面积。     

提高柔性生产线喂料精度的方法探讨

新型板带冲压柔性生产线喂料系统是一种比较特殊的进给伺服系统,与传统的停剪喂料方式相比精度要求更高。本文通过对喂料控制原理的阐述,详细分析了喂料系统全闭环控制状态下喂料长度偏差的原因,通过对受力状态的喂料辊的有限元分析,优化喂料辊辊形,从而改变喂料辊变形时夹送力沿板宽的合理分布,以防止喂料辊与板带产生细微滑动,减小喂料系统振荡,进一步提高全闭环控制系统的稳定性,使喂料精度得到很大提高,并通过理论和实践研究证实了该方法的可行性。     

大型压机落料线浅析

分析了压机落料线作为一种近净成形的工业装备面临的外部需求形势,简单介绍了国内外相关制造企业的一些特点,介绍了落料线的分类及组成特点,举例说明了落料线的工艺流程、工艺参数等。     

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).     

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.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

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.