CO_2保护焊

CO_2保护自动焊,是一种高效率的焊接工艺。它用廉价的二氧化碳气体作为保护气体:广泛应用于低炭钢、低炭合金钢和一部分高炭合金钢制品,这种焊接方法生产率高,它与手工焊相比,效率可提高3～4倍。焊接过程自动进行,焊后又不     

自动焊在现代煤化工项目上的研究与应用

针对国内某大型煤化工项目埋弧自动焊及二氧化碳气体保护半自动焊的应用,对施工过程产生的数据进行统计分析,并得到手工焊与自动焊时间效益和经济效益比值,以及自动焊应用后的焊接一次合格率等数据,充分证明了自动焊在现代煤化工项目应用有明显优势,同时为后续煤化工项目自动焊施工提供依据。     

自动焊在一万立方米金属油罐上的应用

金属罐的焊接,特别是立缝和横缝,多年来都是手工焊,设备多,速度慢,劳动强度大,远远跟不上油田建设发展的需要。为了加速建罐速度,改变焊接落后面貌,我们进行了立缝和横缝自动焊接的试验。立缝的自动焊接,难度较大,没有专用焊机,是很难实现的。鉴于气体保护焊对自动焊接立缝具有一定的有利条件,故在原有二氧化碳气体保护焊管机的基础上,进一步改装成二氧化碳气体保护双枪立焊机,并在油田新开发     

NZA28—800型混合气体保护横向自动弧焊机

用途随着造船工业、机械工业和化工石油工业的发展,船体拼接,油罐、气罐等焊装,对横向焊接采用手工焊,在质量和效率上已不能满足需要,故要采用新工艺。 NZA28—800型混合气体保护横向自动焊机,系用氩气和二氧化碳混合气体作为保护介质进行横向自动焊之设备。焊接电源为平特性焊接整流器,焊接时用直径1.6、1.8和2.0毫米焊丝,焊机头在固定于焊件的齿条上行走进行焊接。所需焊接长度可拼装齿条达到焊接的连续。     

单面自动焊接在造船中的应用

前言所谓单面焊接技术,就是从单面来完成焊接工作。该技术在日本研究得比较早,而且在一些箱形结构和管子等工程上需要施行单面焊接的情况下也已部分地加以应用。一般地谈到单面焊接,其焊接方法的种类也很多:有手工焊、惰性气体保护焊、二氧化碳保护焊、明弧焊等半自动焊接,还有埋弧焊等半自动焊接,还有埋弧自动焊接等。如果仅从单面完成焊接的观点来看,则气电焊、电渣焊、以及熔嘴电渣焊等所谓垂直自     

细丝CO_2气体保护全位置自动焊管机

细丝二氧化碳气体保护自动焊接工艺,近十几年来在国内外发展很快,工艺比较成熟。我们在几年的实际使用中,也充分证明了这种焊接工艺的优越性。关于管线自动焊接设备,国内外都有研究。我们从实际需要出发,研制了野外管线固定管口自动焊及半自动焊机组,经过几年的现场试用和不断改进,现已初步定型,并在生产中应用。一、机组结构及计算本焊机组全部安装在四轮拖车上,其中包括:柴油发电机组、焊接电源、自动焊机头(分单焊枪及双焊枪)、半自动焊手把、二氧化碳供气系统等五部分。     

400MPa级超细晶粒钢电弧焊接头组织性能分析

采用普通电弧焊方法(手工电弧焊、二氧化碳气体保护焊、埋弧焊)对400MPa级超细晶粒钢进行焊接,并对不同工艺条件下的焊接接头进行了组织性能分析.研究结果表明:400MPa级超细晶粒钢电弧焊焊接接头热影响祆区存在着明显的晶粒长大现象;手工电弧焊和埋弧焊焊接接头性能明显下降,而二氧化碳气体保护焊焊接接头性能下降不明显.根据试验结果,实际生产中可以利用二氧化碳气体保护焊方法焊接400MPa级超细晶粒钢.     

二氧化碳气体保护焊

二氧化碳气体保护焊,是用CO_2气体作为保护气体的一种先进的焊接技术。它用于焊接普通碳素钢、低碳钢和高强度合金钢,甚至可以焊接不锈钢、耐热高合金钢和镀层钢。目前,应用较多的是二氧化碳气体保护半自动焊,它是用手工操作,焊丝自动送进,有拉丝、推丝和推拉丝结合三种形式。     

某核级空心叶片自动焊装置及试验

采用机器人自动焊方法对核级空心叶片进行焊接试验,并与手工焊进行对比,分析了焊接接头的微观组织和硬度分布,优化了自动焊接工艺参数.组建自动焊智能焊接系统,设计了仿形体结构工装夹具,与多变位机工位联动搭建自动焊生产线,完成空心叶片试验件的试制,通过试验验证其生产效率较传统手工焊接提升1倍.通过焊接数值模拟分析研究了空心叶片焊接位置和分段焊方案,并与实际叶片焊接进行对比分析,结果表明,自动焊焊接变形趋势与实际焊接过程基本一致,焊缝成形良好.通过研究空心叶片自动焊系统,可以提高核电五级空心叶片焊接的经济性和可靠性,更好地满足产品质量要求,具有较大工程应用价值.     

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…     

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.     

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.     

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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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.