储罐集油槽整体提升工艺及稳定性校核

介绍了一种储罐的倒装施工工艺,即储罐集油槽在罐底上制作完成,然后用电动倒链整体提升,实现整体就位。相比传统的搭设脚手架施工工艺,该项工艺避免了大量的高空作业,有效保证了施工质量、作业人员及设备设施的安全,施工工效是传统工艺的2~3倍。通过对储罐集油槽提升工艺安装过程中稳定性的效核,有效保证了储罐集油槽整体提升过程的安全性,该工艺可以在各类工艺储罐的安装和改造维修工程中推广应用。     

15万m3大型钢制储油罐底板焊接

15万m^3双盘浮顶油罐底板焊接质量及变形控制是保证储罐整体施工质量的关键环节，采用合理的焊接工艺和技术，可有效地避免应力集中，提高施工焊接质量，确保储罐建成投入使用后的安全运行。针对15万m^3双盘浮顶油罐底板的特点，介绍了经实践证明合理、有效的储罐底板焊接工艺和技术。     

大型油罐浮顶单盘板悬空安装焊接变形的控制

介绍了大型油罐控制浮顶单盘安装焊接波浪变形的工艺方法。由于大型油罐浮顶单盘板较薄,面积大,焊缝密度高,交叉点多,传统的自然收缩法的焊接工艺很难控制焊后产生的波浪变形,现采用悬空刚性固定法有效地控制了浮顶单盘焊后的外观波浪变形,保证了油罐的中央排水能力。     

LMU海上连接口焊接工艺开发及现场施工要点

桩腿对接耦合装置LMU是大型组块浮托安装中必不可少的一个装置,也是保证浮托安装成功的关键部件。LMU的海上连接口施工环境恶劣,接头承受较大应力,再加上焊口壁厚较厚且采用低合金高强钢,焊接过程中容易出现各类焊接缺陷。针对惠州25-8项目LMU与导管架的海上连接口开发了免焊后热处理焊接工艺,同时对施工过程中容易出现各类焊接缺陷成因进行了分析,并根据LMU与导管架的海上连接口环境施工特点对现场施工要点进行总结,为今后提高LMU海上连接焊接质量积累了经验。     

钢质管道内环氧粉末喷涂成型工艺探讨

随着我国科学技术的进步,钢质管道的性能指标不断提升,在钢质管道中应用熔结环粉末内成膜工艺,可以省去一些不必要的操作流程,使得环氧涂层成型更加高效,而且能够最大程度上保证管道结构稳定性,具有良好的应用价值.基于此,本文就对钢质管道内环氧粉末喷涂成型工艺的相关内容进行了一个较为详细的概述.     

基于有限元法的精密锻造齿环齿顶折叠的研究

针对钢质同步齿环在精密锻造成形过程中出现的小齿齿顶折叠现象,应用刚塑性有限元理论,利用专业塑性成形模拟软件对同步环的成形过程进行了模拟,获得了齿顶折叠的形成过程与机理.针对齿顶折叠形成的特点,借助塑性成形模拟软件进行了工艺优化,使齿顶的成形方式由原工艺的挤扩成形转变为镦挤成形,消除了齿顶折叠现象,获得了无折叠的齿环锻件.生产试制验证了研究结果的可靠性.     

3000m~3油罐底板焊接变形的控制

0 前言我公司承担了4台3000m~3原油罐的施工任务。3000m~3油罐是圆筒形的大型贮油罐,内径16m,高17.6m,它主要由罐底、罐壁、罐顶及内浮盘等组成。在施工过程中遇到了油     

钢管内涂标准SY/T 4078-1995应尽快修订

石油天然气行业标准SY／T4078—1995《钢质管道内涂层液体涂料补口机补口工艺》在适用范围、焊口表面处理、现场施工过程及焊口补口涂层检验等部分都有不妥之处。成功的工程实例表明：无溶剂环氧树脂作为管线内壁涂层的补口涂料是非常合适的,它可以使传统的补口工艺更加科学、合理。为保证钢管内壁涂层的整体质量应尽快予以修订该行业标准。     

铝制内浮顶储罐的化学清洗

主要介绍了内浮顶储罐的特殊结构以及在清洗过程中如何防止清洗除铁锈的同时,对铝制浮顶的腐蚀及损伤.经正交实验筛选的清洗剂,在吐哈油田甲醇厂清洗的实际应用中取得了良好的效果.     

大型外浮顶储罐防腐施工工艺

本文主要以大型外浮顶储罐防腐施工为研究对象,针对大型外浮顶储罐防腐施工工艺及流程要点问题进行研究与分析,以期可以进一步提高大型外浮顶储罐的防腐施工效果。     

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).     

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.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。