连续管测井机注入头液压系统的设计

注入头是连续油管测井机的核心部分,其液压系统采用目前先进的电液集成控制技术,实现模块化、集成化设计,提高连续油管测井机的自动化水平.根据连续管测井机注入头的主要功能和技术要求以及连续管测井作业的工艺特点,液压系统方案中,设计满足负载特性要求的主驱动回路和辅助驱动回路.在此基础上,应用自动控制技术,实现连续管测井机工作过程的自动化.实验结果表明:连续管测井机注入头液压系统工作可靠,是一种理想的连续管注入头液压系统.     

步进加热炉神经网络电液比例速度控制技术研究

目前先进的步进加热炉液压传输系统一般采用非对称闭式泵控电液比例控制系统,该控制系统是一种典型的非线性、时变、强干扰系统,采用常规PID控制策略,难以实现某些特殊钢种所要求的精确速度控制.本文作者通过对非对称闭式泵控电液比例控制系统动态特性分析,提出了一种FNNC控制策略,通过试验和现场应用表明,系统的跟踪速度、精度、缓冲特性、循环时间较采用PID控制系统均有所改善或提高,能更好地满足生产要求.     

宝钢CT80-CT100高钢级连续油管用钢实现批量供货

<正>日前,宝钢一批连续油管用高强度酸洗钢卷发往美国用户。连续油管是一种可缠绕在滚筒上连续、无接头的小口径直缝焊管,具有机动性强、作业效率高、可重复使用等优点,是一种满足节约环保、可持续发展要求的热轧高端产品。     

液压绞车的一种恒张力设计

对一种采用比例减压阀和比例溢流阀控制液压马达恒定扭矩的绞车原理进行详细分析。这种方式适用于小功率的绞车,且系统简单、控制容易,可以和其他液压设备共用液压源,减少系统投资。     

海上铺管软管滚筒驱动装置液压系统设计与仿真研究

针对国内海上软管铺设滚筒驱动装置的研究现状,设计一种新型的软管滚筒液压驱动装置.该装置使用液压马达驱动滚筒,带有一定扭矩进行顺时针和逆时针旋转,即带一定张力进行软管的施放和回收.利用Matlab Simscape建立液压系统数学模型,进行系统性能仿真分析.仿真结果表明该滚筒驱动装置在软管施放和回收工作状态下滚筒转动平稳,能够满足海上软管铺设要求.     

轮式起重机起升卷扬闭式液压系统控制研究

论述轮式起重机起升卷扬开式液压系统控制要点和闭式液压系统常规控制原理,提出一种新型控制技术用于控制轮式起重机起升卷扬闭式液压系统。原理为在起升卷扬闭式液压系统中设置一平衡阀,利用平衡阀特性来解决起升卷扬闭式液压系统启停溜钩、冲击震动等难题;利用平衡阀负载安全特性避免液压系统驱动管路一旦爆裂或发动机一旦出现飞车故障负载失速坠落现象发生;通过平衡阀先导内外联控,解决平衡阀在闭式液压系统中发热问题。实践证明,所设计的QLY系列轮式起重机起升卷扬闭式液压系统控制技术性能稳定可靠。     

基于AMESim的多功能液压试验台闭式系统元件选型分析

液压传动系统是工程机械整机重要的传动系统之一,而液压多功能试验台是面向工程机械液压传动系统研究的一个科学试验平台。介绍一种多功能液压试验台闭式马达泵系统元件的选型:根据实验要求,选择满足试验目的闭式马达;根据马达的参数,计算出可以与马达相匹配的闭式泵和电机的参数。将选择好的元件设计成闭式马达泵系统,然后用AMESim进行建模仿真分析,得到马达转速、扭矩变化曲线、泵出口压力变化曲线等。仿真试验结果验证了所设计的液压系统功能的正确性和合理性、元件选型的正确性。     

潜水器恒张力收放绞车系统的建模与仿真

在潜水器收放过程中,要求收放绞车具有恒张力控制功能,减小由于波浪起伏对潜水器的冲击、本文根据液压系统的流量连续性方程,建立恒张力收放绞车泵控液压马达系统的数学模型,并对该系统进行了仿真分析,仿真结果表明：该系统能够满足实际的作业工况,且具有良好的动态和稳态工作性能。仿真结果为收放系统的设计提供了依据     

拖曳收放系统的电液伺服研究

以拖曳收放系统为研究对象,设计拖曳收放的液压系统,介绍收放过程中的工况,给出张力调定和计算方法;分析收放液压绞车的同步运动关系,推导出马达的传递函数;引入伪微分控制算法,并对波浪补偿进行仿真。结果表明:伪微分控制算法具有很好的响应特性,严格满足系统要求。     

基于二次调节技术的液压绞车系统分析及性能研究

建立了由限压式变量泵供油、蓄能器储能、电液比例伺服阀控变量液压马达的液压绞车容积调速系统。利用AMESim软件,建立了液压绞车比例伺服控制系统仿真模型,利用该模型对系统的性能进行仿真研究。结果表明:该调速系统具有很好的速度跟踪特性、较高的速度控制精度以及较好的系统工作稳定性,同时具有显著的节能效果。     

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.