新型管道内补口技术在输卤工程中的应用

介绍了钢质管道新型内涂层补口机的结构、技术性能及其在淮盐输卤管线内补口施工中的应用。该补口机具有摄像观察功能、高效除锈功能和焊口内涂层补口功能。用于管道内防腐蚀补口,施工质量稳定,技术简单,操作方便,施工费用较低。应用实例表明,新型管道内补口技术是一种性能优异的施工技术,值得推广。     

防腐管道整体喷涂补口技术研究

现场补口涂层作为整个涂层体系非常重要的一部分，应与管道主体防腐涂层结构具有很好的相融性，但现场补口施工其补口工艺控制的难度比在工厂内预制要大得多。有时不能完全达到理想状态。因此，要对现场补口方法进行研究。本文针对上述问题介绍了大庆油田建设集团工程设计研究院在“防腐管道现场整体喷涂补口技术”研究中的喷涂3PE粉末涂料补口技术、PE防腐管道喷涂聚脲补口技术和管道补口工程车。     

管道内壁涂装防护及焊缝补口新工艺

管道壁涂装防护技术的瓶颈是现场安装焊接后焊缝的涂层补口处理。介绍了管道内壁防护的现状及管道内壁涂装防护和焊缝补口的新工艺。     

SLF高性能双组份液体环氧冬季补口技术

本文根据辽河油田恶劣的气候和苛刻的土壤腐蚀环境，针对冬季熔结环氧涂层埋地管道现场快速补口的施工要求和技术性能，综合分析了国内外埋地管道熔结环氧涂层的外补口技术状况，通过性能和现场实际应用的比较，选用国家金属腐蚀控制工程技术研究中心研制的SLF冬季外补口技术，该技术具有良好的现场施工性和长效防腐性。     

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。     

实例说明石油天然气行业标准SY／T 4078—95中的问题

石油天然气行业标准SY／T 4078—95《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。     

钢管外3PE涂层现场补口装置的研究

钢管外涂层采用同类的工艺方法和材料补口是最优选择。为了保证补口与管体寿命一致，钢管外3PE涂层采用了3PE方法和材料现场补口是最理想的，中油管道防腐工程有限责任公司许传新，刘月芳，于洪波，中油管道第四工程公司赵晓华在本文中结合国外装备情况及运用多年的经验，介绍了钢管外3PE涂层现场补口装置情况。     

小口径长输管道防腐补口施工策略

小口径长输管道防腐涂层部分的管道防腐补口位置处于管端连接口环向焊缝处,焊缝高度和表面焊接缺陷直接影响补口施工质量,就此,本文对小口径长输管道防腐补口施工策略进行详细探讨。     

解决3层PE管道现场补口问题势在必行

从3层PE管道现场补口暴露出来的大量问题,提出对现行管道防腐蚀质量表示担忧;认为GB/T 23257-2009《埋地钢质管道聚乙烯防腐蚀层技术标准》要求不严格也是导致补口质量下降的一个原因。本文根据现场条件,介绍了一种较好的防腐蚀材料,该材料具有施工工艺简便的特点。结合现场应用实例,希望能进一步提高管道的防腐蚀水平。     

西气东输二线海管现场补口施工质量控制

目的深港支线海底管道采用环氧底漆-热缩带-开孔型高密度聚氨酯泡沫补口,介绍深港支线海底管道补口施工过程及控制要点。方法通过对材料、设备、施工人员及施工过程的有效控制和管理,保证补口施工的质量。结果深港支线海底管道施工完成后,经过现场检测,补口质量满足DNV RP F102和ISO 21809-3的技术要求,填充泡沫的抗压强度及密度等指标满足设计要求。     

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).     

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.     

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.     

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.