矿用提升机恒减速制动系统研制（英文）

现有矿井提升装备恒减速安全制动装备主要采用模拟控制,在紧急制动过程中存在平稳性差、减速度超调严重等问题,因此提出软硬件冗余全数字控制的恒减速控制系统。该系统采用了一用一备的液压控制回路;在电气方面,选用两套PLC300控制器以实现控制算法的软硬件冗余,采用两套PLC1200控制两套电液伺服比例阀,实现液压控制系统的硬件冗余。利用仿真软件Simulation X对所研制样机进行建模,以完善控制器算法和参数。最后对样机进行测试,结果表明所提方案具有良好的性能。     

中频炉双CPU冗余控制的实现

本文介绍了在东风铸造二厂中频炉自动控制系统中,为保证服务器系统的稳定性和安全性,通常用两台配置相同的服务器共同构成一套冗余服务器系统.采用两套硬件.容错服务器采用硬件级的容错技术,采用一套系统软件,以达到消除系统切换时间的目的,选用西门子S7-300双CPU的PLC控制器,以硬件方式实现CPU冗余控制.该控制方案具有投...     

精锻机专用控制系统的设计与实现

提出了一套完善且实用的精锻机专用控制系统研发方案，包括开发润滑系统以保护主机锻造箱和操作机夹头等关键部件，设计液压辅助系统为精锻机提供稳定的源动力。同时，基于精锻机高频旋转锻造原理规划了锤头锻打、夹头旋转和操作机进给等运动控制系统。在此基础上，采用工业控制计算机和4类多功能控制卡的控制模式对专用控制系统进行具体实现。以Python作为软件开发工具，利用多功能控制卡、PLC和中间继电器实现了稳定的软硬件通讯，很好地实现了对精锻机各子系统的高精度控制。研发了具有自主知识产权的精锻机专用数控系统，为精锻机的应用和继续改进奠定了基础。     

PLC在车载装备液压翻转机构中的应用

由于PLC具备高可靠性、自动化程度高、故障率低等优点,装备越来越多的使用PLC进行过程控制,本文介绍了使用西门子PLC S7-200对车载装备液压翻转机构进行逻辑控制,根据翻转机构的工艺要求,分别对其软硬件系统设计进行了详细说明,经过运行表明,本系统具备高可靠性和稳定性.     

基于双CPU的冗余控制研究与实现

根据工业控制系统中对PLC的高可靠性要求,提出了双CPU的PLC冗余控制措施,并分析了基于A-B Control-Logix PLC的双CPU冗余控制的具体实现方法,包括软件冗余实现方式和硬件冗余实现方式.     

某型武器装填液压系统的PLC控制研究

介绍某型武器装填液压系统的工作原理,研制以可编程控制器(PLC)为核心的控制系统,对控制系统的硬件结构、控制软件设计以及抗干扰措施等进行详细介绍.实验结果表明该PLC控制系统实现对武器装填液压系统的运动控制,达到预期控制要求.     

冗余设计在PLC控制系统中的应用

在实施工业生产自动化的过程中,容错技术是一种满足连续生产要求,提高控制系统可靠性和可用性的有效手段。本文以容错技术中的关键设计技术——冗余设计在PLC控制系统中的应用为例,简单介绍了几种冗余控制的类型和实现方式,并对PLC控制系统中常有的处理器冗余、通信冗余、I/O冗余和电源冗余等类型的冗余,从原理、实现方式等方面进行了分析和比较。     

节能型提升机恒减速液压制动系统的研究

研究恒减速液压制动系统,以制动减速度恒定为控制目标,包含一级和二级紧急制动功能,能够在大负载范围内实现安全制动,松闸时能耗低.采用模糊神经网络控制克服模糊规则不容易制定的缺点,具有在线学习收敛快、可靠性高的优点.     

基于 PLC与组态技术的变转速液压系统设计

在液压综合实验台的改造设计中采用三菱FX1N系列PLC进行控制,用PC作为上位机实时监控整个控制系统,用PLC作为下位机在现场控制仪器设备,构建一个简单、直观的液压换向回路,实现了机电液一体化的完美结合.     

试验装备电液控制系统设计与稳定性监测分析

针对试验装备电液控制和工作稳定性的问题,设计了一种基于可编程控制器的装备控制系统,给出了液压系统和3种控制回路的原理图;确定了PLC伺服控制I/O线路接口图,并且编写了PLC控制程序;然后,以试验装备4种工况为基础,探讨了其稳定性的分析方法,设计了稳定性监测软件,并进行了可视化仿真。结果表明：在工况4这种情况下的试验装备稳定性较好。     

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).     

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.     

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.