最新刊期
期 4 ， 2020
- 摘要：TiAl alloy has a combination of advantages,including low density,high specific strength,excellent oxidation resistance and high-temperature creep resistance,which has broad application prospects in aerospace and other fields. However,TiAl alloy,with the poor room temperature ductility,is difficult to fabricate, and the traditional technology preparing TiAl alloy has low efficiency and high cost,therefore,the engineering application of TiAl alloy is significantly limited. In recent years,with its technical advantages such as high efficiency and low cost,the additive manufacturing technology has great advantages in the preparation of TiAl alloy components. In this paper,the basic characteristics of TiAl alloys are introduced,the research status of the technology preparing TiAl alloy is summarized from several aspects,including traditional preparation technology,laser additive manufacturing, electron beam additive manufacturing and the wire-arc additive manufacturing. The research progress and improvement methods of mechanical properties of additive manufacturing TiAl alloy are summarized as well. Finally,the future research issues and development trends of TiAl alloy additive manufacturing are analyzed and estimated.关键词：TiAl alloy;additive manufacturing;review
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发布时间：2022-03-15 - 摘要：The selection principle of HR3C steel welding consumable in engineering application was discussed. The results show that the weld metal is mostly different from the base metal when the selected consumables are used under engineering conditions. The selection of high-quality,proper welding consumables and optimized welding process is an important technical means to control and improve the weldability of the steel. The so-called "structure matching" principle of dissimilar welds is the use of nickel-based austenitic welds with the Ni-Cr-Co-Mo alloy system to ensure that the joint can obtain satisfactory comprehensive service properties（including high temperature properties） and weldability. GTAW is the practical process in engineering,and test results indicated that the comprehensive properties of the typical welding consumables have obvious advantages.关键词：welding consumable;HR3C austenitic heat-resistant steel;selection principle;engineering application;dissimilar weld
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发布时间：2022-03-15 - 摘要：Friction stir channeling process（FSCP） is a patented solid-state process technology to produce sub-surface channels in monolithic aluminum components in a single step,it can be used for forming internal fluid channel and reducing weight in components. The technical progress of FSCP,and the process technology principle and application problems of a new TWI invention--stationary shoulder FSCP technology manufacturing aluminum alloy liquid cooling flow channel are intro-duced. Through the welding process analysis and X ray tomography detection, the results show that the geometry,rotation speed,feed speed and vertical force of the stirring tool are the key technology factors affecting the forming of liquid cooling channel. The metal section on the retreat side of the channel presents an irregular interface shape due to the mixing and extrusion and the plasticizing flow of the metal during the friction stir process.
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发布时间：2022-03-15 - 摘要：The laser K-TIG hybrid welding experiment is carried out on the 304 stainless steel plate with thickness of 4 mm. The high-speed camera and image processing technology are used to collect and analyze the arc shape in the process of laser K-TIG hybrid welding,and explore the influence law of various welding parameters on the arc shape. The results show that proper energy ratio is the key to arc stability. When the laser focus is near the anode,the arc section enlarges,so that the laser energy absorbed by arc increases and arc is stable. When the laser focus is close to the cathode,the arc fluctuates violently and the arc stability reduces. Therefore the optimal heat source spacing range is 0～3 mm,and the optimal defocus distance is 0 mm.关键词：K-TIG;laser hybrid welding;arc shape;image processing
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发布时间：2022-03-15 - 摘要：This paper aims at the determination of eigen value of 2024 aluminium friction stir welding（FSW） joint. By collecting data on the geometry of the 2024 aluminum alloy Ldirection friction stir welding joint under different welding parameters. The sensitivity of joint microstructure information to welding parameter was calculated by the correlation analysis.The eigen value of 2024 FSW joint was determined by further correlation analysis between joint microstructure information and property of welded joint. An example was given to illustrate the criterion of joint eigen value to joint performance.关键词：friction stir welding;relativity;joint eigen value;weld joint property
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发布时间：2022-03-15 - 摘要：According to the main characteristics and technological process of surfacing welding of a nuclear power product. It is designed to a high performance PLC control system based on the Device Net Bus,which is equipped with digital welding power source,double tungsten electrode welding torch,touch screen,servo positioning control system,arc voltage high speed processing system,wireless automatic communication system,automatic welding three-dimensional slide frame and other elements of double tungsten electrode surfacing equipment. The field test shows that the system has strong the reliability,automation,anti-jamming ability and expansi-bility. The surfacing welding efficiency is 1 times higher than that of single tungsten electrode. These test items which are UT flaw detection,weld chemical composition,bending performance,intercrystalline corrosion,hardness,metallographic st-ructure and other detection items,are qualified.关键词：PLC control;double tungsten;digitization;DeviceNet Bus control system;weld shaping
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发布时间：2022-03-15 - 摘要：In this paper,a pulse MIG welding machine is designed. The ARM chip of STM32F407 is used as the control core to expand the peripheral circuit,and the driving signal generated by UC3846 chip is used to drive the main circuit of the full bridge soft switch inverter. Based on the constant wire feed rate and the mode of arc voltage feedback regulat-ing duty cycle,the arc length control in the welding process is realized. This machine has the basic protection functions of overload,overheat and abnormal voltage. And the digital interface has the characteristics of convenient parameter adjustment. The welding technology test shows that the pulse MIG welding machine designed by the current and voltage double closed-loop control mode has good arc length adjustment ability,and the weld quality can meet the welding requirements.关键词：ARM;pulse MIG;double closed-loop control mode;constant wire feed rate;regulation of duty cycle
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发布时间：2022-03-15 - 摘要：A kind of rail-type automatic all-position pipeline welding equipment was developed. Aiming at the complex welding working conditions,the designs of key mechanism parts such as horizontal and vertical sliding blocks with sealing and dust-proof function,swing mechanism of welding gun with multi-dimensional adjustment function,rack type quick disassembly guide rail were improved. By using this automatic welding equipment,many groups of automatic GMAW pipeline welding tests were carried out,the mature welding parameters were obtained,and the macro metallographic,tensile,side bending and impact tests were carried out. The results show that this developed equipment can be used in the automatic all-position butt welding of the bridge steel tubular column. At present,this equipment has been applied in the automatic butt joint welding operation of bridge steel tubular column in the Huangling project site.关键词：steel tubular column;all-position;automatic pipeline welding;GMAW;rail type
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发布时间：2022-03-15 - 摘要：The DC power output tracking command current of the electric welding machine has some problems such as static error and poor anti-interference ability when three-phase PWM rectifier is controlled by traditional proportionalintegral（PI）. For these problems,the quasi-PR of inner ele-ctric current loop is adopted,the PI of outer input current loop and outer voltage loop is adjusted,and the double closed loop control strategy of output voltage is also adjusted,the shortcomings of traditional linear PI control are overcome. In this paper,the mathematical model of the system is established,and the principle of SVPWM generator and quasi-PR controller is analyzed. The simulation results show that the SVPWM control strategy of DC electric welding machine based on quasi-PR can realize the complete non-static tracking of electric welding machine DC power unit power factor and current,and the electric welding machine power has good anti-interference ability and excellent rectification quality.关键词：quasi-proportional resonance（quasi-PR）;SVPWM;electric welding machine DC power supply;non-static error;anti-interference ability
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发布时间：2022-03-15 - 摘要：Bi-metal composite pipe and corrosion-resistant alloy prefabricated inner-filled steel pipe have been widely used in oilfields due to their excellent corrosion resistance and performance-free joint characteristics. Especially the corrosionresistant alloy prefabricated inner-filled steel pipe is relatively inexpensive. In recent years,the cost has been promoted in a large area of high-corrosion ground pipelines in domestic oil fields,and has achieved very good results. Due to the differences in the chemical composition,microstructure,and physical properties of the inner and outer layers of the bimetal composite pipe, the commonly used butt welding process has the problems of complex procedures,difficult operation,high construction costs,and strict requirements for welder skills,which can easily cause composition segregation,dilution of corrosion-resistant alloy components,poor internal bead forming,false welding,carbon migration,and structural changes in the fusion zone caused by heat input. This article starts from the factors that affect the quality of bimetal welds,and takes the horizontal fixed butt welding of stainless steel composite pipes as the research object.Research and experiments have been carried out from the bevel form, the pairing method,the welding method of the corrosion-resistant alloy underlayer and the bimetal transition welding layer,and new process methods such as internal sealing of composite pipes,U-shaped groove free-space group pairing,back protection of the molten pool,unfilled fusion welding bottoming and unfilled fusion welding transition have been proposed.Through X-ray inspection and welding process evaluation,combined with microstructure analysis,comprehensively evalu-ated the welding process and concluded.
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发布时间：2022-03-15 - 摘要：In this paper,an 8 mm thick TC4 titanium alloy thick plate was used as the experimental material. Under the test conditions of two kinds of welding methods:manual tungsten inert gas arc（TIG） welding and metal inert-gas arc（MIG）welding,the similarities and differences of formation of weld,microstructure,mechanical properties and tensile fractures were studied. The results show that both TIG and MIG have good formation of weld,but the MIG welding speed is faster;the base metal is α+β dual phase microstruc-ture,the grain of the MIG welding heat affected zone is more uniform than that of TIG welding. Both welds are composed of thick columnar crystals,and the microstructure is α’ martensite +β phase. The strength coefficient of manual TIG welded joint is 97.3%,and the strength coefficient of the oscillating arc MIG welded joint is 93.9%. The reason for the low strength of the oscillating arc MIG welding is the existence of blowhole defects in the weld.关键词：titanium alloy;medium thick plate;TIG welding;oscillating arc MIG welding;microstructure
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发布时间：2022-03-15 - 摘要：The characteristic parameters can be extracted from both experimental and numerical specimens and the mapping relations can be established by BP artificial neural network. The output parameters can be then predicted based on the massive input data. Friction stir welding is taken as example. The input parameters include rotating speed, welding speed and the distance from weld centerline. Weld hardness is taken as output parameter. 3-10-1 3-layer topology model of6061-T6 aluminum alloy friction stir welding head hardness BP artificial neural network is established. The data from 13 conditions with different rotating and moving speeds are selected for training and testing in BP artificial neural network model. The comparison with experimental data shows the validity of the established BP artificial neural network model.The test results show that BP artificial neural network has good ability for prediction of joint hardness,which provides a new technical method for prediction of mechanical property of weld.关键词：friction stir welding;hardness;BP artificial neural network;characteristic parameter
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发布时间：2022-03-15 - 摘要：Taking the water tank of ordinary railway passenger vehicle as the research object,in the process of train acceleration and deceleration,the liquid sloshing problem in the water tank was modeled and numerically analyzed using a two-way fluid-solid interaction method. By studying the gas-liquid two-phase flow distribution state in the water tank,the stress time history diagram and displacement history diagram of the water tank are obtained,and a more accurate analysis of the structural strength of water tank is achieved. By comparing with a water tank without wavebreakers,the cushioning effect of the wavebreakers in sloshing is further clarified,which provides practical and reliable analysis method for the design of tank structure of railway passenger vehicle.关键词：water tank;two-way fluid-structure interaction;numerical analysis;structural strength
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发布时间：2022-03-15 - 摘要：Comparing with steel structure,aluminum and its alloys have the advantages of light material,no low temperature brittleness,corrosion resistance and easy pressure processing. Although the principles of the structure design and welding for aluminum alloy do not change comparing with steel structure,but the strength,elastic modulus,density,thermal conductivity and thermal expansion coefficient of aluminum alloy are significantly different from steel,so the strength design and joint details of welded joint are quite different from the steel joints. The main point of this paper is the weakening of the strength of welding heat affected zone, the details of welded joints including groove type and back protection and so on. The former is analyzed by EN1999-1-1 and the latter is analyzed by ISO9692-3 and EN1011-4.关键词：steel structure;welded joint of aluminum alloy;welding HAZ;reduction in strength
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发布时间：2022-03-15 - 摘要：The microstructures and hardness of nickel-based WCp/Ni60 composite layers prepared by plasma transfer arc surfacing with different transfer arc currents were analyzed to study the effect of transfer arc current on WC particles reinforced nickel-based（WCp/Ni60） composite layers. By controlling different transfer arc currents,Ni60 +25% WC（casting） powder was deposited on the Q235 carbon steel plate by plasma transfer arc surfacing,and well-formed and crack-free plasma deposition layers were successfully obtained under reasonable technological conditions;the hardness of the deposition layer was positively correlated with the transfer arc current of plasma surfacing,when the transfer arc current was135 A,the hardness was more than 590 HV5. The WCp/Ni60 composite layers of plasma surfacing under different transfer arc currents had obvious stratification phenomena. In the upper layers,the coarse star-shaped and needle-like Cr23 C6 were distributed in the nickel-based solid solution and nickel-based eutectic microstructures. The sectional area ratio of WC particles in the lower layers increased from about 15% at 165 A to about 40% at 135 A.
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发布时间：2022-03-15 - 摘要：Aiming at the intergranular corrosion of base metal and welded joint of Super304H steel pipe during high temperature operation, the intergranular corrosion sensitivity of base metal and welded joint of Super304H steel pipe was systematically studied by welding test, intergranular corrosion test,metallographic examination and other detection means.The results show that the intergranular corrosion susceptibility of Super304H steel pipe decreases when the C content reduces and the Nb/C ratio increases,and intergranular corrosion susceptibility of welded joint increases as the heat input and interpass temperature increase.关键词：Super304H steel;C content and Nb/C ratio;intergranular corrosion susceptibility;interpass temperature
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发布时间：2022-03-15 - 摘要：A low temperature reheater specifications is φ50.8 ×4.0 mm and material trademark is SA213-T91.Continuous fracture of steel tube occurs when the cold bending plastic deformation exceeds 90°. Through the chemical composition analysis,mechanical property test,metallographic exa-mination,microhardness and fracture morphology analysis of steel tube,the bending fracture causes are determined. The high carbon content on the internal surface of SA213-T91 cases the high hardness and a sharp decline in plasticity of the internal surface of steel tube,resulting in steel pipe bending angle cracks by brittle cleavage when cold bending. Based on the analysis of manufacturing technology,casting segregation exists during the manufacturing of die casting billet,and the head is not cut clearly,resulting in the heart carburization in the tube blank and the carburization phenomenon on the internal surface of steel tube.关键词：serpentine tube;cold bending fracture;heart carburization
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发布时间：2022-03-15 - 摘要：In the present work,6082-T6 aluminium alloy with a thickness of 6 mm was used as the base material,and the plasma-CMT hybrid welding was carried out. The effect of welding parameters on the weld formation was studied. The microstructure characteristic,hardness distribution and tensile property of the plasma-CMT hybrid welded joint were also researched. The optimized welding parameters obtained were as follows:plasma current 130 A,wire feeding speed 8 m/min,welding speed 50 cm/min and plasma gas flow 7 L/min. The fine equiaxed grain was found in the weld center. The heat affected zone was very narrow and had the lowest hardness value. The tensile tests results showed that tensile strengths of the welded joint could reach up to 228.4 MPa,which was77.4% of that of the base material. The tensile test fracture area located on the heat affected zone,and the tensile fracture morphology was characterized by ductile fracture.关键词：aluminum alloy;plasma-CMT hybrid welding;microstructure characteristic;hardness distribution;tensile strength
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发布时间：2022-03-15 - 摘要：Through the welding thermal simulation technology,the microstructure,hardness and impact toughness of the overheated zone of Q450 NQR1 high-strength weathering steel with different welding heat input were studied. The results show that as the welding heat input increases,the microstructure of the pro-eutectoid ferrite changes from needle to block,granular bainite content gradually increases,overall hardness gradually reduces,low temperature impact energy has little difference,the impact fractures are all cleavage fractures,the edges are in the form of dimples with different sizes.关键词：Q450NQR1 high-strength weathering steel;welding heat input;coarse grain zone;microstructure;impact property
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发布时间：2022-03-15 - 摘要：The impact toughness and fracture toughness of laser-MIG hybrid welding joints of A7N01S-T5 aluminum alloy for high-speed trains under the temperatures of 20 ℃,0 ℃,-20 ℃,-40 ℃ and -60 ℃ were carried out. The results showed that at the same temperature,the impact toughness and fracture toughness of the heat affected zone（HAZ） was the best,the base metal（BM） was the second,and the weld metal（W） was the worst. With the decrease of temperature,the impact toughness and fracture toughness of the three zones（HAZ,BM and WM） of laser-MIG hybrid welding joints had been improved to a certain extent,but the changes were small.The size of toughness dimples on fracture surface in the heat affected zone and the base metal were larger than that of the weld metal. During the fracture process,large dimples could produce large deformation to resist the crack growth,absorb more energy,and show good fracture toughness.关键词：A7N01S-T5 aluminum alloy;laser-MIG hybrid welding;low temperature toughness;crack growth resistance;dimples
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发布时间：2022-03-15 - 摘要：Laser cladding welding of 1Cr17Ni2 martensitic stainless steel sheet on 27SiMn alloy structural steel was carried out under different welding conditions by laser welding. The laser welding simulation was carried out under the same conditions by Msc.Marc software. The finite element numerical simulation results are compared with the experimental data.The compar-ison results show that the Marc finite element software can effectively predict the welding stress and strain,and can pretreat the material according to the simulation results to reduce the residual stress. Under the condition that the laser power is 400 W and the welding speed is 0.8 m/min,the rigid displacement of the plates is constrained by the fixture in the experiment and simulation,and the deformation of the welders is reduced by 95.3% and 95.9% respectively. At the same time,the welding deformation was simulated and corrected by the prestress method. Under the tension of 800 N,the plate deformation was reduced by 29.3%. The test results show that the method of rigid fixation and prestress can effectively reduce the welding deformation.关键词：stainless steel sheet;laser welding;numerical simulation;Msc.Marc;welding deformation
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发布时间：2022-03-15 - 摘要：This paper briefly introduces the current trend of laser welding of high silicon aluminum alloy at home and abroad, and introduces the analysis process of ANSYS laser welding finite element simulation in detail. The process of temperature field analysis is introduced from the aspects of heat source loading, element birth and death technique and transient thermal analysis. The temperature field distribution cloud map is obtained by ANSYS postprocessor. The instant-aneous stress distribution of welding is obtained by thermal structure coupling process. The temperature field obtained by simulation meets the requirements of welding temperature,and the stress field distribution will produce some deformation.关键词：high-silicon aluminum alloy;grid generation;volumetric heat source;birth and death element;universal post-processor
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发布时间：2022-03-15 - 摘要：This paper mainly studied the double-sided arc backing welding process of central groove,the weldability tests have been done by using dissimilar steel,semi-mechanization method and automatic method were studied both. Designed different gap width and root face height,the microstructure of the test joints and their mechanical properties are studied by means of the optical microscopy（OM）,the mechanical properties measuring equipments. The results show that the gap width is2～3 mm and the root face height is 0～2 mm,which is the best parameter for the implementation of semi-automatic and automatic MAG double-sided arc backing welding process,and the excellent welding joint can be obtained.关键词：central groove;double-sided arc welding;backing weld;semi-mechanization;automatic
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发布时间：2022-03-15 - 摘要：Maintaining the running and continuous improvement of EN 15085 welding system is very important for the welding manufacturers of railway vehicles and components.With the higher and higher requirements on welding quality of products,how to let more employees master and participate in the operation of the welding system has become an issue for enterprises. Not only does this article analyze the key points of the implementation of man,machine,material,method,enviro-nments and traceability in the running of the welding system,but also it summarizes the common problems in welding coordination,weld joint design,production weld tests,certification level CL 4 and certificate application,and puts forward suggestions for improvement. This article provides feasible guidance for enterprise personnel to understand and maintain EN 15085 welding system.关键词：standards EN 15085;railway vehicle;welding;welding quality system
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发布时间：2022-03-15 - 摘要：<正>关注重点:激光焊、激光-电弧复合焊、激光切割发展现状与趋势,大功率激光焊接技术、小功率激光诱导电弧复合焊技术、手持激光技术、设备和应用,激光焊接和切割如何实现低成本化,激光焊接缺陷的评判与消除,管道自动化切割技术、激光预控破片技术、激光焊接及激光熔敷、异种材料激光焊接
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发布时间：2022-03-15 - 摘要：<正>专刊内容:论文发表、高校及企业重点实验室介绍、平面宣传等寻找合作伙伴:国内外高校及企业重点实验室、与高校合作的生产制造、装备和材料企业论文发表:028-83289008品牌宣传:028-83282678 83279528新媒体推广:028-83271528
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发布时间：2022-03-15 - 摘要：<正>激光制造的精密可控性,对加工材料的普适性,与智能技术的良好融合性,激光制造技术有望成为未来主导性、革命性的高度智能化先进制造技术。《电焊机》杂志第7期将开展"激光加工"专题,重点研讨激光焊接、激光-电弧复合焊、激光表面工程及再制造、激光增材制造等技术的研究进展及趋势,及其在航天航空、汽车、海洋装备、轨道交通、石油化工、微电子制造、核能等领域应用。
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发布时间：2022-03-15 - 摘要：<正>关注重点:国内外增材制造技术（3D打印）现状和发展趋势,增材制造质量控制与评价、增材制造的控形控性、提高增材制造质量的方法和工程化前景,激光及电子束增材制造、电弧增材制造、电熔增材和增减材混合制造等增材制造方法的发展及应用,激光增材修复技术、固相增材制造、热处理及表面处理等发展状况,硬质合金堆焊、特殊异形件的增材制造,新材料的运用、最新的耐磨
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发布时间：2022-03-15 - 摘要：<正>2020年初的新冠疫情给全中国按下了"减速键"甚至"暂停键"。4月15日国务院联防联控机制发布会上,介绍要做好重点场所重点单位重点人群疫情防控工作情况,指出各类展览及会展暂不开展。为更好贯彻落实中央及政府关于应对疫情防控工作部署,焊接行业的盛会第25届北京·埃森焊接与切割展览会及其配套活动均延期至2021年6月16～19日举行。
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发布时间：2022-03-15
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