基于表面张力控制的全位置焊机设计

分析了STT（surface tension transfer)理论及其优点，提出一种新颖的全位置打底焊控制思路。在此基础上介绍了所研制的STT全位置自动打底焊机，包括整机机械和电气2部分。其中电气部分着重介绍了控制系统的软、硬件组成及其功能。     

基于熔池受力的全位置STT打底焊分段工艺

油气管道在全位置焊接时通常按照固定角度机械化地进行分段,此过程中,熔池容易发生失稳流淌而导致焊缝成形不良。文中对管道全位置焊接过程中的熔池受力进行了分析,建立了一种基于熔池径向力变化的新型分段工艺,以解决全位置焊接时管道内、外壁成形不良的问题。通过对220 mm×10 mm×400 mm的X70管线钢采用STT打底焊试验发现,该分段工艺抑制全位置焊接时的熔池失稳流淌问题有良好效果,且内壁成形更加平滑美观,对于管道自动焊接过程中的分段问题具有一定的参考价值。     

STT打底焊与内焊机打底焊工艺在管线焊接中的应用

STT打底焊是一种成本比较低的焊接工艺,且适用于比较复杂的施工地形,应用较广泛。而内焊机打底焊又是一种焊接生产效率非常高、自动化程度非常高的焊接工艺,且施工地势越平坦,性价比越高。文中较详细地介绍了上述2种焊接工艺在管线施工中的应用。     

厚壁管TIG打底焊工艺分析

从单焊道全位置区段分析,送丝行为分析、焊接弧长（电压）、电流行为分析、工艺试验和接头检验等诸方面介绍了管道全位置打底焊焊接工艺特点,其研究成果对全位置焊接机的制造和调试具有普遍指导意义。     

STT型CO2焊在全位置焊中的应用

着重阐述了STT型CO2焊的焊接特点以及在全位置焊中的应用。     

STT根焊技术在管道焊接中的应用

分析了STT根焊技术的特点、原理,阐述了STT焊接坡口形式,焊接工艺参数中送丝速度、基值电流、峰值电流等对焊道成形的影响以及焊接工艺参数的设置。针对STT焊接操作技术,详细介绍了STT根焊在不同焊接位置时的后拖角、焊接干伸长的控制、熔合性能的保证、焊接熔池的控制以及焊接运弧、错口技术的处理技巧等,并总结了焊接飞溅过大、焊接密集气孔、焊道熔合不良等常见焊接问题及其解决措施。     

STT根焊在西气东输二线管道焊接工程中的应用

根焊道(打底焊道)的焊接是管道焊接的关键,根焊的焊接质量和焊接速度将直接关系到整个管焊接质量和工程进度.介绍了河北华北石油工程建设有限公司在西气东输二线管道工程焊接施工中采用STT焊接工艺进行根焊道焊接的方法、特点以及现场质量控制.     

核电站TIG全位置自动焊打底工艺分析

TIG全位置自动焊工艺是一种先进的焊接生产技术,受人为因素影响较小,且自动化程度较高,实用性强。对于此工艺而言,打底焊接是其中的关键技术难题。结合国防科工委核能开发科研项目《核岛辅助管道自动化焊接应用技术研究》中核心子课题——TIG全自动焊工艺,对其打底焊接工艺进行较为详细的分析和研究。介绍了TIG全自动焊中打底焊接工艺的影响因素——先决因素和工艺因素,针对先决因素提出解决途径,针对工艺因素找出其内在规律。     

一九八九年《焊接技术》总目录

第一期 焊接接头形式对二氧化碳焊未焊透的影响 二氧化碳气体保护焊打底焊在锅炉辅机压力容器制造中的应用 粗丝二氧化碳气体保护焊在起重机主梁制造中的工艺试验及其应用 不锈钢压力锅复合铝底的钎焊工艺研究 采用混合焊剂抑制焊缝中的CO气孔· NCA7一300型程控脉冲钨极氨弧全位置焊管机电气部分原理分析 一单侧无垫板点焊在空腹钢结构上的应用 不锈钢薄板双枪钨极氨弧焊的试验及应用 铝合金艇艇体的焊接工艺 关于209埋弧焊接头冷弯开裂原因的分析 压力容器常用钢热影响区的范围及其性能 石油钻杆磨擦焊接缺陷的成因及其超声波检测 自动…     

油气管道自动焊电源的研究

在输油输气管道施工中,全位置自动焊在国内已经推广几年了.行走小车和控制系统都已实现国产化,有代表性的是中国石油工程研究院和中国管道科学研究院研制的自动焊系统.但在焊接电源方面一直采用飞马特焊机和林肯焊机,这种焊机价格昂贵,维护成本较高,焊接电源的国产化已迫在眉睫.自2004年开始,本公司分别同中国石油工程研究院对采用国产STT电源进行了打底焊的研究,同管道四公司对采用波形控制的MAG气保焊电源进行了填充、盖面焊的研究.     

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.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

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).     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

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.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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