差压式管道检测机器人及其速度控制的研究现状

随着油气输送管道里程的迅速增长,管道检测机器人越来越多地应用于管道的检测与清理,管道检测机器人的行走稳定性问题得到了广泛的关注。分析了国内外差压式管道检测机器人及其速度控制技术的发展现状,针对现有水平对大规模实用化需求的较大差距,提出了急需解决的3个问题,为进一步研究高智能化的差压式管道检测机器人提供参考。     

新型能源自给式管道机器人的原理设计与研究

管道机器人可以对管道进行低成本高效率的检测和维护。目前的管道机器人受到能源供给的限制,不能长时间远距离进行工作。本文以新型无缆管道机器人的能源供给方式为基础,详细论述了新型能源自给式管道机器人总体结构设计,发电蓄能部分结构设计、支撑轮组件的设计和导向机构设计,这些设计为建立新型能源自给式管道机器人的模型并进行速度控制奠定了基础。     

流体驱动式管道裂纹检测机器人探头结构设计

管道机器人能有效的检测出油气管道存在的腐蚀缺陷,但对管道存在的裂纹缺陷无法有效的检出。设计了一种流体驱动式管道裂纹检测机器人的探头结构,可用于管道轴向裂纹的检测。论述了探头总体结构设计、弹簧支撑结构设计、支撑轮设计和检测探头壳设计。对设计的探头结构进行测试,结果表明:测试里程超过250 km,满足现场使用要求。该探头结构的设计为管道裂纹检测机器人的研制提供了参考。     

自主式管道清淤机器人的研究

提出了一种自主式管道清淤机器人,介绍了该机器人的工作原理及各组成部分的结构和功能。该机器人采用轮式行走机构和同步带传动机构,蓄电池供电和电机驱动,无线通讯和PLC控制。自主式管道清淤机器人的研究提高了排水管道清淤的效率和管道清淤作业的自动化水平。     

管内机器人的开发

针对石油天然气长输管道焊接,采用焊口固定的全位置焊接,增加了大直径、厚壁石油天然气管道的焊接难度.在简要分析大直径、厚壁石油天然气管道焊接、探伤、检测现状的基础上,结合焊接施工现场的环境特点,介绍了一种适用于大直径、厚壁石油天然气管道焊接、探伤、检测使用的管内机器人,着重阐述了管内机器人的机械结构、控制系统硬件、控制软件开发等关键技术问题.以及使用管内机器人作为管道自动化作业平台,以机电功能模块,组装各类专用管道机器人,实现大直径、厚壁石油天然气管道焊接、探伤、检测的自动化.     

水库涵管检测用十字结构全向型管道机器人研究

该管道机器人是为了提高地方水利员人工检测水库(山塘)涵管隐患的工作效率而设计的,做到机器换人,大幅度提高野外检测效率.水库涵管检测用十字结构全向型管道机器人的结构是由一个十字结构作为机器人的基本框架,在十字的各个驱动腿顶端安装驱动轮,可以根据管壁具体地形自适应变化.该机器人的通行平面是管道中心水平面,可以最大限度地避开山塘涵管淤泥问题,且能大幅度提高管道错位越障能力.     

水库涵管检测用十字结构全向型管道机器人研究（英文）

该管道机器人是为了提高地方水利员人工检测水库(山塘)涵管隐患的工作效率而设计的,做到机器换人,大幅度提高野外检测效率。水库涵管检测用十字结构全向型管道机器人的结构是由一个十字结构作为机器人的基本框架,在十字的各个驱动腿顶端安装驱动轮,可以根据管壁具体地形自适应变化。该机器人的通行平面是管道中心水平面,可以最大限度地避开山塘涵管淤泥问题,且能大幅度提高管道错位越障能力。     

基于视觉的管道内焊缝检测机器人研究

在分析管道机器人现有移动机构的移动机理及典型变径调节机构力学特性的基础上,设计了一种基于视觉检测技术的管道内焊缝检测机器人。该管道机器人适用于直径为400~800 mm的管道,利用CCD高清摄像头对焊缝进行检测,可以在控制端实时显示缺陷信息,避免了工人进入管道作业,提高了作业效率。     

自适应管道打磨机器人的通过性分析与仿真

针对管道机器人难以检测打磨管内缺陷且通过性差的问题,设计一种自适应管道内壁检测打磨机器人,研究其在直管、弯管以及障碍管中的通过性能。提出管道机器人的结构方案,分析其行走驱动装置及作业装置特点;建立机器人的运动学模型,结合结构在管道内的受力,对机器人在不同管道内运动的受力状态、几何约束与运动特性进行分析;运用ADAMS仿真软件和整体化仿真方法,对机器人在管道中的通过性能进行仿真分析。结果表明：该机器人可以通过水平直管、弯管和内含10 mm高环形障碍的管道,但机身速度、压力和车轮的接触力存在一定波动;在通过弯管时,采用内外车轮差速、外扩变径机构,可降低内耗、增加贴合力。     

管道检测机器人在垂直输气管道的运动分析

管道检测机器人用于管道腐蚀缺陷和变形缺陷的定期巡检,当管道存在较大倾角时会对机器人的运行状态产生影响,尤其是机器人进入垂直管道内运行,机器人自重将明显影响设备的运行速度,严重时可能导致机器人超速运行,影响检测数据质量。利用动量守恒定律建立了在垂直管道向下运行时机器人前后端气体的压差增量与机器人运行速度增量间的关系式,指出压差增量与气体的密度、扰动波传播速度和机器人的速度增量等因素有关。建立了机器人在垂直管道内运行加速度和运行距离的关系式,并对关系式进行了简化,方便工业现场应用。通过与数值仿真结果对比,建立的关系式可有效计算出机器人在垂直管道内运行时的速度增量和运行距离,为工业现场预测机器人的运动参数提供了保障。     

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.