轧机AGC液压缸智能检测系统平台研发

针对轧机AGC液压缸静动态特性性能指标测试技术第三方验证的重要性,开发一套人机交互式AGC液压缸试验台检测系统,采用厂级ERP企业管理系统,实时远程控制与测试,实现第三方与生产厂家的轧机AGC液压缸性能指标测试数据的检定、校准工作与报告生成。结果表明：该系统平台可有效提高轧机AGC液压缸性能指标测试数据准确性,测试功能满足第三方需求。     

伺服液压缸试验台动态性能研究

根据某钢厂AGC液压缸测试试验台的需要,设计了AGC测试缸加载机架和液压控制系统。利用传递函数方法建立了液压控制系统模型,得到了系统开环伯德图。根据设计的液压控制系统计算了相关参数,在有负载干扰的情况下得到了系统的阶跃响应曲线和20 Hz下的正弦响应曲线。结果证明加载控制系统能满足AGC液压缸动态试验20 Hz的响应要求。     

比例电磁铁静动态特性检测系统设计

比例电磁铁是多种电液比例阀重要的执行器件,其静动态性能对比例阀有关键影响。为准确方便快速地测试比例电磁铁的各种静动态特性,设计并研制了一种比例电磁铁性能测试系统。该系统由机械平台、位移和拉压力传感器、计算机采集控制系统和上位机VC++6.0开发的测试软件组成。实验结果表明:该系统测试结果准确可靠,操作方便,能够用于常见比例电磁铁的静动态特性测试。     

首钢中厚板轧机AGC计算机控制系统

介绍了首钢中厚板轧钢厂3340mm中厚板轧机液压AGC系统工艺参数和计算机系统的硬件配置和传感器配置,给出了轧机弹跳模型和液压缸HCC的控制原理和液压缸的系统频率响应特性,描述了本系统所采用的头部锁定AGC和绝对AGC的控制策略,并对支撑辊偏心补偿、油膜厚度补偿等厚度控制补偿方法进行了说明。     

全液压十一辊矫直机的多嵌入式协同控制系统

以中厚板精轧机生产线上全液压十一辊矫直机的控制系统为研究对象,提出一种全新的基于多个嵌入式系统的协同控制架构及控制策略;建立了面向实时任务的预定义模型,变集中计算为分布式计算;实验及运行结果表明,该分布式协同控制系统,可使4个AGC液压缸的随动性能更加可靠,模型运算速度加快,动态跟随误差为0.2mm。     

轧机伺服液压缸测试动态位移的应变等效方法研究

对于轧机伺服液压缸动态性能的测试,目前国内还缺乏成熟的测试系统,其中位移传感器的安装方式是制约动态响应的关键因素。针对目前测试方法的研究现状,提出了一种新的大型轧机伺服液压缸动态性能测试,提高了测试系统的动态响应能力。     

纯水液压人工肌肉驱动系统的动态特性研究

将液压仿生人工肌肉系统作为一种液压传动控制系统,同时将液压仿生人工肌肉视为变截面积液压缸,在液压缸动态特性方程的基础上推导出描述液压仿生人工肌肉驱动系统动态特性的非线性数学模型,并用计算机仿真分析该系统的动态工作特性,为该系统动态特性的实验研究奠定基础。     

Automation Studio在液压系统设计中的应用

介绍面向系统原理图的液压系统仿真软件Automation Studio。以捞油车液压驱动系统设计为例,在Automation Studio平台下进行模拟,对两变幅液压缸的压力、加速度及其机械特性进行研究,并在Bosch Rexroth实验台安装、调试系统,相关参数测试结果与软件模拟结果基本相同。表明这种仿真方法能准确地模拟实际系统的工作状态,简化建模和参数调节过程,为液压系统设计及动态特性研究提供一种好方法。     

基于LabVIEW的双液压缸同步控制系统的开发

针对液压缸同步要求,构建了基于Lab VIEW的实时采集控制系统。该系统利用采集卡实现了对主、从液压缸位移的实时检测,通过增量式PID结合控制卡实现了对从液压缸位移的闭环控制,从而保证了从液压缸对主液压缸的实时跟踪,达到同步控制的目的。测试结果表明:该控制系统能够很好地控制主、从液压缸的位移,同步精度高,完全符合实际使用需求。     

双路刹车压力伺服阀性能测试系统设计

为满足某大型飞机双路刹车压力伺服阀静、动态性能测试的需求,研制一套可实现双路压力伺服阀实时测试的具有柔性化负载加载的测试系统。分别从集成化油路设计、可调容腔模拟负载设计以及双路实时测试实现等角度开展研究。试验结果与设备长期运行结果表明所研制的测试系统与装备满足实际测试功能与测试精度的要求,且工作稳定、可靠。     

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.     

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.