最新刊期
期 1 ， 2020
- 摘要：Additive manufacturing is an advanced manufacturing technology with great potential,which is suitable for aerospace manufacturing which requires light weight and high strength. The principles and characteristics of different kinds of additive manufacturing are briefly expounded,and the research status of additive manufacturing in key technical directions such as forming equipment,forming organization and performance regulation, topology design and optimization,forming process simulation,heat source planning and control software,online detection and control,residual stress and crack porosity control,and auxiliary manufacturing measures are introduced. Application examples of additive manufacturing for large-scale metal components are presented. The existing problems and development trend of additive manufacturing technology of large-scale metal component in aerospace manufacturing are discussed.关键词：additive manufacturing;aerospace;large-scale metal component
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发布时间：2022-03-15 - 摘要：To explore the residual stress distribution in soldering,the procedure and simulation of Au80Sn20/Sn63Pb37 solders in soldering 6061 aluminum alloy/4J34 Kovar alloy substrate are studied in this paper. The influence of the soldering procedure on the residual stress of the soldered joints is studied,and the soldering parameters are optimized by simulation and experimental study of residual stress. The results show that the residual stress near the Kovar side soldering seam is higher,and the soldered joint is more prone to fracture on the Kovar side.For Au80Sn20 solder,at the same soldering temperature,the residual stress at the aluminum alloy soldering seam increases slightly with the increase of the soldering time. For Sn63Pb37 solder,different soldering temperatures and soldering times have little effect on the numerical results. The measured results of X-ray residual stress are in good agreement with the calculated values,which proves the correctness of the simulation results,and provides an effective method for studying the reliability of lightweight alloy soldered joints in electronic products.关键词：soldering;6061 aluminum alloy;4J34 Kovar alloy;residual stress;numerical simulation
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发布时间：2022-03-15 - 摘要：The relationships between the criterion of crack initiation site for high-strength steel and the weld strength matching were reviewed. The results show that the criterion of cold crack initiation site is an indirect method to judge the cold crack sensitivity in root pass welding for high strength steels by weld hardness. Among the influencing factors of criterion of the cold crack initiation site for high-strength steels,the applied stress is a necessary condition for cold crack initiation or alternate initiation,while the changes of hydrogen concentration and weld hardness are sufficient condition for cold crack initiation or alternate initiation. The type of weld strength matching has a good correspondence with the "criterion of cold crack initiation site ",which can well explain the rules and phenomena in the "criterion of cold crack initiation site " test.The implementation process of weld strength matching based on the criterion of cold crack initiation site is put forward.关键词：criterion of alternative initiation site of cold cracking;weld strength matching;diffusible hydrogen;weld hardness;applied stress
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发布时间：2022-03-15 - 摘要：Aiming at the problem of the effect of defocusing amount on the paint removal mechanism,a high-speed camera optical filter amplifier system was designed to photograph the dynamic process of paint removal at different defocusing amounts. The surface microtopography of paint removal at different defocusing amount was photographed via scanning electron microscopy,and the effect of defocusing amount on paint removal mechanism was analyzed by combining high-speed camera videos and scanning electron microscopy figures. The results show that at the defocusing amount of 0 mm,the paint is mainly removed by thermal stress,melting and gas impact. At the defocusing amount of +4 mm,the paint is mainly removed by thermal stress,melting and evaporation.关键词：defocusing amount;metallic paint;thermal stress;melting;gas impact
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发布时间：2022-03-15 - 摘要：Through studying the friction and wear behaviors of arc deposition of stainless steel high-entropy alloy powder core wires under different friction conditions,it can provide reliable guarantee in wear resistance for rapid repair and formation of arc in situ. Four metal elements,Fe,Co,Ni and Cu,consisting of high-entropy alloys,were made into stainless steel high-entropy alloy powder core wire by equal atomic ratio of powder.The wire was deposited on the surface of stainless steel by arc deposition. Nanovea Tribometer friction and wear tester and nanovea PS50 surface profiler were used to test and analyze the wear resistance of bead surface. High-entropy alloys are unevenly dispersed in stainless steel welding layer with FCC phase. The wear resistance of bead is higher than that of stainless steel. The wear volume and wear rate of bead are 30% lower than those of base metal and 308 powder core wire. The FCC phase of high-entropy alloys has a strengthening effect on the wear resistance of stainless steel. With the increase of wear load and wear rate,the friction coefficient of high-entropy alloy bead decreases gradually,and the depth,width and volume of wear mark increase. At the wear load of 2 N and 4 N and wear rate of 100 r/min and 200 r/min,the wear resistance of layer is 1.5 times of stainless steel base material and JQ-308 stainless steel powder core wire,which is mainly characterized by abrasive wear. At the wear load of 6 N and 8 N and wear rate of 300 r/min and 400 r/min,the wear resistance of the layer is twice as much as that of the stainless steel base material and JQ-308 stainless steel powder core wire material,which is mainly characterized by adhesive and exfoliative wear. Applying the high-entropy alloy with exce-llent properties in arc deposition by the way of powder core can realize rapid arc repair or surface strengthening of key parts in the actual environment.关键词：high-entropy alloy;powder core wire;stainless steel;arc deposition;friction and wear
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发布时间：2022-03-15 - 摘要：By anodic oxidation,a dense oxide film was produced on the surface of CNT/2024 Al composite prepared by powder metallurgy. The effect of anodic oxidation on the corrosion behavior of CNTs reinforced Al-alloy composite was studied by salt spray corrosion test. The evolution of surface and cross section of anodic oxide film under salt spray was investigated by SEM,and its effect on mechanical property of composite after salt spray corrosion was further studied. The results show that the non-anodized samples will be corroded remarkably when exposed to salt spray,and the tensile strength and elongation will greatly decrease. By anodic oxidation,stable dense oxide film of about 2 μm can be formed on the surface of the composites. Compared with the non-anodized samples,the corrosion under salt spray can be effectively prevented,and the mechanical properties of the materials do not significantly reduce.关键词：anodic oxidation;salt-spray corrosion;Al matrix composites;CNTs
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发布时间：2022-03-15 - 摘要：Titanium and titanium alloys are widely used in automobile,biomedicine,aerospace,petrochemical,marine engineering and other fields due to their high specific strength,low density and good corrosion resistance. Compared with con-ventional tungsten argon arc welding,double tungsten argon arc welding can suppress welding defects and improve welding speed. In this paper,the corrosion resistance of industrial pure titanium TA2 double tungsten argon arc welding joints is studied.The result shows that double tungsten argon arc welding improves the corrosion resistance of industrial pure titanium and expands its usable range in severe environments.关键词：industrial pure titanium;double tungsten argon arc welding;corrosion performance
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发布时间：2022-03-15 - 摘要：18 groups of orthogonal experiments were designed for CMT seam welding of 3.0 mm and 2.5 mm thick Q345NQR2 weathering steel sheets. Eight typical positions of 18 groups of welding experiments were measured by 3D scanner,and the absolute deformation of each point was analyzed,and the optimal welding point with the largest deformation was point 5 at the end of the welding. The deformation of plate in clamping and releasing state is analyzed and the deformation law of clamping and releasing is obtained. The deformation of the plate was analyzed with the parameters of feeding speed of 7.0 m/min,welding speed of 0.42 m/min,welding gap of 1.5 mm,air supply speed of 20 L/min and arc length modified of-30%. The spatial deformation rule of the plate was obtained,which provides important reference for welding deformation control.关键词：CMT seam welding;multi-point deformation;laser measurement;Q345 steel sheet
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发布时间：2022-03-15 - 摘要：Frictionstirrivetin（gFSR）hasachievedremarkable success in the joining and processing of aluminum alloys and steels. In this paper,the classification and mechanism of FSR are summarized. The joint types,the microstructure transformation of joint area,the kinds and influence factors of interfacial inter-metallic compounds and the failure mode of the FSR for alu-minum alloy and steel were analyzed and summarized. A great deal of research indicated that based on the microstructure transformation,the joint area can be divided into anchoring zone,thermal-mechanical affected zone and heat affected zone.Due to the friction heating,mechanical reactions occurred at the joining interface,it is easy to generate intermetallic compounds FexAl（yx<y）,which is harmful to the comprehensive properties of the joints. However,the harmful intermetallic compounds can be reduced by addition of Zn element,galvanization or Zn-AlMg coating.关键词：friction stir riveting;aluminum alloy and steel dissimilar materials;ficrostructure transformation;intermetallic com-pounds;failure mode
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发布时间：2022-03-15 - 摘要：Aiming at the harmonic pollution caused by the traditional switching power supply bridge rectifier filter,the high efficiency bridgeless power factor converter has become a research focus in academia and industry at home and abroad.Based on the dual-diode bridgeless PFC（2nd DBPFC）converter,the converter system design and components selection are completed,its working mode is analyzed in detail,and the 2nd DBPFC converter control system is completed combining the average current control strategy. Finally,based on the PIC32MK1024 MCF064 chip with DSP core,a 1 kW 2nd DBPFC converter was developed. The test results show that the converter has a power factor of 98.7% at 220 V input full load.关键词：bridgeless PFC converter;working mode;average current control
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发布时间：2022-03-15 - 摘要：Vanadium base alloy has been considered as leading candidate for fusion energy systems. To construct more effective and economic system,dissimilar materials joints between vana-dium alloy and stainless steel are required. The high vacuum electron beam isolation welding（EBIW） was used to join vanadium alloy（V-5Cr-5Ti） to stainless-stee（lHR-2） with the composite coatings Ni+Au. The results show that with EB off-set to the vanadium alloy side,the penetrating crack formed in the interface of joint between vanadium alloy and stainless steel,which directly lead to welding failure. And with EB off-set to the stainless steel side,electroplated Ni+Au composite coatings as good isolation layer,well inhibited the generations of intermetallic compounds at the V/Fe interface,and significantly improved the weld quality. The maximum tensile strength of EBIW joint of vanadium alloy/Ni +Au/stailess-steel is up to 430 MPa. The vanadium/stainless steel dissimilar metal welded joints obtained by EBIW have good appearance of both sides of the welds,and there is no crack and porosity defect detected in the joints through X-ray inspection.关键词：electron beam welding;vanadium alloy;stainless steel;composite coating
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发布时间：2022-03-15 - 摘要：The main engineering applications and market prospects of high-frequency welded pipes was briefly introduced.Sulfuric acid dew point corrosion test and blasting test were conducted on ND steel high-frequency welded pipes under three different states（as-welded,normalized and tempered）,and was compared with the seamless tube. The results show that the sulfuric acid dew point corrosion resistance of ND steel high-fr equency welded pipe in the as-welded,normalized and tempered state is equivalent to that of the parent metal. The pressure bearing capacity in as-welded state and heat-treated tempering state is equivalent to that of the seamless pipe. The pressure bearing capacity in normalized state is weak and the economy is also poor. Considering the sulfuric acid corrosion resistance and pressure bearing capacity,ND steel high-frequency welded pipe and seamless pipe performance is equivalent in as-welded state and tempered state,so seamless pipe can be replaced by ND steel high-frequency welded pipe.关键词：ND steel;high-frequency welded pipe;feasibility;welding
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发布时间：2022-03-15 - 摘要：Continuous laser butt welding procedure expe-riments were carried out on A3 steel sheet to study the influence of different procedure parameters on the quality of welding.The results show that the width,depth and tensile strength of molten pool of welded joint increase with the increase of laser power. With the increase of welding speed,the width,depth and tensile strength of molten pool decrease gradually. The defocusing amount has little effect on the joint morphology and tensile properties. Effective welding can be achieved by keeping the tensile strength of the joint basically unchanged when the weld gap is below 50 μm.关键词：laser butt welding;A3 steel;procedure parameters;weld gap
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发布时间：2022-03-15 - 摘要：7N01 aluminum alloy is the key material of high-speed train body,which is often welded in different welding positions. In different welding positions,the adaptability of the joint to different positions is the key to determine the actual production process design. In this study,using the method of MIG and the current welding technology of high-speed train,the flat welding joint,overhead welding joint and vertical up welding joint of high-speed train structural material 7N01 were prepared,the macroscopic appearance of the joint was observed,the structure and performance of the welded joint under different positions were studied,and the influence of different welding positions on the joint performance was analyzed. The results show that the welding process at different welding positions can ensure the quality of the welded joint,and the tensile strength of the joint is the highest at PA position.关键词：7N01 aluminum alloy;high-speed train;welding position;microstructure and properties
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发布时间：2022-03-15 - 摘要：Taking 6061-T6 aluminum alloy used in undercarriage floor of maglev train as the research object,the research is focus on the fatigue strength of 6061-T6 aluminum alloy laser-MIG composite welding joint at low-high tempera ture（-40℃,room temperature,70℃）,provide basic experimental data for maglev train design under wide environmental cond-itions. The result shows that,the fatigue limit at room temperature is 67.1 MPa,weld fracture has obvious labor source zone,fatigue expansion zone and instantaneous fracture zone;the fatigue extension zone has obvious fatigue striation,local fatigue fray of different clusters;the instantaneous fracture zone has obvious dimple structure,and the instantaneous fault zone is ductile fracture. The fatigue limit of low temperatur e（-40 ℃）condition is 61.3 MPa. The fatigue crack of the weld fracture is fine and dense,and there are a large number of secondary cracks, and the weld ductility is reduced. The fatigue limit of high temperature（70 ℃） condition is 56.2 MPa,and the fatigue fracture of weld fracture is characterized by quasi-cleavage fracture. A large number of brittle fatigue ridges are distributed in the fracture and the transient zone is a typical aggregated dimple.关键词：6061-T6 aluminum alloy;welding joint;wide-area environment;fatigue property
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发布时间：2022-03-15 - 摘要：This paper compares and analyzes ISO5817 and MT/T587 one by one,which are common domestic and foreign defect standards of hydraulic support structures,main including defect categories,corresponding detection levels and acceptance levels. Main differences between domestic and foreign standards are as follows:1. Defective acceptance is only a part of MT/T587,which scope of application is more wider than ISO 5817,but it is less systematic,concrete and comprehensive;2.MT/T587 only has specific provisions on surface defects and geometric shape defects. However,it does not explain internal defects in detail and defective acceptance is only required to comply with GB/T11345 provision;3. As for surface imperfec-tions and geometric imperfections,Ⅰclass level of MT/T587 is more critical than C class level of ISO5817. Finally,counter-measures of common imperfection are formulated:1. To reduce stress concentration, it is recommended to adopt welding toe grinding;2. Both standards allow the existence of internal poro-sity and inclusion defects,but should meet the assessment limit;3.Although defect of geometric shape reduces the bearing capacity of the joint,it can increase thickness of the welding seam to compensate.关键词：hydraulic support;defect standards;compare and analyze;otherness;countermeasures
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发布时间：2022-03-15 - 摘要：The spray forming 7075 aluminum plates with thickness of 3 mm were welded by friction stir welding（FSW）using the same welding parameters under different media. The effects of different media on the joint of the thermal cycle curve,macro morphology,microstructure,hardness and mecha-nical properties were discussed. The results show that the thermal cycling curve of underwater welding tends to be more smooth and high temperature residence time is shorter. The weld surface of the underwater welding is forming better than that formed in the air. The grain of underwater joint is finer and the heat affected zone is narrow with clearly plastic manifold. The heat affected zone of under-air joint is softening seriously which hardness is only 113 HV. The fracture form of underwater joint is dissociation fracture,while the welded joint in air is fracture of quasi dissociation.关键词：7075 aluminum alloy;friction stir welding;thermal cycling;microstructure;mechanical properties
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发布时间：2022-03-15 - 摘要：The axle-box body of high-speed train is mainly made of nodular cast iron with heavy overall quality.According to the lightweight requirement of 400 km/h high-speed train,the axle-box structure is redesigned according to the forming characteristics of aluminum alloy materials. The three-dimensional model and finite element model of alu-minum alloy axle-box is established by CERO and ANSYS,respectively. Based on the EN 13749-2005 standard,the stress state and fatigue strength of aluminum alloy axle-box under the super load and operation conditions are analyzed by ANSYS Workbench. Through static strength and fatigue strength analysis,the safety and reliability of aluminum alloy axle-box structure are verified.关键词：axle-box;aluminum alloy;static strength;fatigue strength;Workbench
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发布时间：2022-03-15 - 摘要：The bobbin tool friction stir welding 6005-T6 aluminum alloy profile joint was repaired once under the same process parameters,and the fracture surfaces of fatigue specimens were analyzed by SEM. The result of SEM scanning showed that,the fatigue strength of welded joints after repairing is lower than that of welded joints without repairing. With the increase of stress,the difference of fatigue strength between the two joints decreases from low stress zone to high stress zone.The fatigue limit of unrepaired welded joint is 101.7 MPa,and the fatigue limit of repaired joint is 75 MPa in lifting fatigue test. The Fracture analysis shows that,there are no obvious defects in the fracture surface of the specimen repaired once.The fatigue fracture position is mainly concentrated in the parent mental zone,the secondary crack propagation is less,the surface of the fracture initiation zone is smooth,and the fatigue beach are clear and gross. A large number of shallow dimples can be observed in the terminal area,which is a ductile toughness fracture.关键词：6005-T6 aluminum alloy profile;bobbin tool friction stir welding;repair joint;fatigue performance
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发布时间：2022-03-15 -
Research on fatigue property of the welded joints of Q345E steel plate for express freight car bogie
摘要：Q345E steel plates for express freight car bogie were welded by metal active gas arc welding（MAG） welding method. After post weld nondestructive testing,the fatigue performance tests of the qualified welded joints were carried out. According to the test results,the fatigue S-N curve of the welded joint was drawn up,the fatigue limit and standard deviation of the welded joint were determined by lifting method. The fatigue failure mechanism of the welded joints was determined by fracture surface analysis of fatigue specimens.The results show that the porosity and slag defects in the weld have significant impacts on the fatigue properties of the welded joints,which will become the initial positions of fatigue cracks and deteriorate the fatigue properties of the welded joints.关键词：argon-rich CO2 welding;fatigue limit;S-N curve;scanning electron microscope;fatigue fracture surface- 28
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发布时间：2022-03-15 - 摘要：In order to analyze the cause of bars breaking of squirrel-rotor by intermediate frequency induction brazing of traction motor of a certain locomotive,fracture microstructure has been analyzed by electron microscopy scanning macro metallography. The fracture site stress distribution under different contact modes between rotor core punch and bars,and the influence of natural frequency on bars of the rotor has been analyzed by finite element software. The bars breaking preventive measures of the repaired motor and the improvement scheme of the new motor has been put forward to solve the questions,which has solved the breaking of rotor,and ensured the safety of the locomotive operation.关键词：traction motor;bar fracture;failure analysis
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发布时间：2022-03-15 - 摘要：Through the X-ray analysis of the welded joint of aluminum alloy conducting pipe,it is found that there are defects such as porosity,slag inclusion,incomplete fusion and incomplete penetration in the joint. The causes of defect were analyzed in detail,and defects in conductive tube welding joint defects were eliminated by optimizing groove structure and welding method,adjusting welding torch position and welding parameters.关键词：aluminum alloy conductive tube;welding defects;X-ray inspection;welding technology
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发布时间：2022-03-15 - 摘要：In order to implement the GMAW automatic welding of steel bar piercing plug weld under inclined position in the shielding building of a third generation nuclear power plant,the effects of welding path,welding posture and welding gas selection on weld formation are studied through experi-ments in this paper. The results show that 360 degree alter-nation and refining layers can effectively control the flow of molten pool to ensure the weld reinforcement within 2 mm;When the working angle of the welding gun is adjusted to 15°and the welding direction angle is 6° ～10°,the arc force can effectively offset the tangential component of gravity and effectively avoid the lack of fusion for the side-wall and the interpass;compared with φ （Ar）98%+φ （O2）2% mixed gas,φ（Ar）80% +φ （CO2）20% ratio can significantly increase the surface tension of molten pool metal to ensure the quality of weld formation.关键词：piercing plug welding;path planning;GMAW automatic welding;weld formation
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发布时间：2022-03-15 - 摘要：By understanding the principle and charac-teristics of arc brazing,we can determine the process plan for arc brazing of aluminized zinc and stainless steel plates. The welding power source and welding wire are selected according to the base material. The welding parameters of the aluminized zinc plate are determined through process tests and metall-ographic analysis. Arc brazing achieves a direct welding con-nection between dissimilar metal,especially for galvanized,tinned,aluminized zinc plates and other coatings. It can ensure the corrosion-resistant capabilities after welding, and would be significant for the popularization and application upon pro-duction design.关键词：aluminized zinc plate;MIG arc brazing;aluminum bronze welding wire;welding specification
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发布时间：2022-03-15 - 摘要：<正>2020年《电焊机》杂志迎来了发刊50卷,感恩陪伴我们走过50个年头的每一位朋友,期待与您的每一次交集。2020年第9期正值杂志发刊第50卷总第400期,一场感恩盛典诚邀您的莅临。2020年《电焊机》杂志将精心组织策划"2020’长输管道焊接技术研讨会",为行业每一位朋友呈现一场管道焊接技术的盛宴,期待与您分享知识、交流经验。2020年《电焊机》杂志将在北京埃森展期间,结合埃森专刊、现场技术交流、展会现场直击等活动与您共享埃森盛会。2020年《电焊机》杂志将紧跟国际焊接技术前沿趋势,结合国家重大制造业先进焊接技术应用要求,开设"石油、
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发布时间：2022-03-15 - 摘要：<正>亲爱的焊接专家、作者和读者朋友:当您翻开这期刊物的时候,旧岁已经远去,新的一年悄然来临。愿新年的阳光一直洒在您的脸上!博观而约取,厚积而薄发,《电焊机》在2020年9月将迎来第50卷400期,春华秋实50载,您我一起走来,因为有您,才有了我们!2020年,中国科技期刊将迎来最好的机遇,"中国科技期刊卓越行动计划"已开始行动。《电焊机》作为国内唯一的关于"焊接设备"的学术刊物,苦下功夫,多约好稿,提高学术引领力和对高水平作者的吸引力,刊发精品文章是我们的年度目标;"激光焊接专题""埃森展专刊及配套活动""长输
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发布时间：2022-03-15 - 摘要：<正>《电焊机》（月刊）是由成都电焊机研究所主办、成都电焊机杂志有限公司编辑出版的国内外公开发行的国家级焊接专业学术期刊。本刊主要刊登国内外焊接各学科领域的反映焊接新设备、新工艺、新材料、新检测方法等研究论文及专题综述,开设栏目包括"重点关注""焊接设备""焊接工艺""焊接材料""焊接教学与培训""焊接管理""绿色焊接"等,以现代焊接装备为核心关注点。《电焊机》被评定为中国科技核心期刊,被中国知网、万方数据、《中文核心期刊（遴选）数据库》、英国《科学文摘》和俄罗斯《文摘杂志》等多种国内外著名文献检索系统收录,欢迎投稿与订阅（邮发代号:62-81）!
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发布时间：2022-03-15 - 摘要：<正>《电焊机》杂志是中国科技论文统计源期刊（中国科技核心期刊）、《中文核心期刊数据库》收录期刊"、英国《科学文摘》（INSPEC）来源期刊""俄罗斯《文摘杂志》收录期刊""美国《剑桥科学文摘》（CSA）收录期刊""波兰《哥白尼索引》（IC）"收录期刊等。各地邮局均可订阅,邮发代号:62-81,订价:15元/月,180元/年。
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发布时间：2022-03-15
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