最新刊期
期 6 ， 2019
- 摘要：The formation conditions of acicular ferrite, the influence of acicular ferrite on weld toughness and the control mechanism of acicular ferrite of X80 pipeline steel weld are discussed. The results show that the weld microstructure of X80 steel is composed of a large number of acicular ferrite plus a little proeutectoid ferrite. In the factors affecting acicular ferrite,the chemical composition and cooling rate of the weld play a decisive role. There is a corresponding relationship between the morphology and quantity of acicular ferrite in welds and weld toughness,the effect of welding heat input on weld toughness is more complex and there is an optimal value for heat input. The optimized weld alloy system and chemical composition are necessary conditions to control the acicular ferrite formation in the weld,and the reasonable procedure methods and welding parameters（including heat input） are sufficient conditions to control acicular ferrite formation.关键词：acicular ferrite;weld metal;toughness;heat input;X80 pipeline steel
- 29
- |
- 155
- |
- 0
发布时间：2022-03-15 - 摘要：1.5 mm and 0.7 mm Invar sheets are lap-jointed by pulsed tungsten inert gas（pulsed TIG） welding in overhead position.The macro morphology,microstructure and mechanical properties of the lap joints are investigated. The results show that when the peak current increase,the characteristic dimensions Laand P obviously increase and R rarely change. The weld metal（WM） zone is composed of coarse austenitic columnar crystal with cellular substructure,and the heat affected zone（HAZ） is composed of coarse equiaxial crystal. The plane grained region and partial melting region constitute the bond,which is the weakest region in the joint.Microhardness tests reveal that the microhardness value of HAZ is less than that of WM and base metal. The maximum tensile shear force of all samples is approximately 4 300 N,and all fractures are located in bond.关键词：invar alloy;pulsed TIG welding;overhead position welding;microstructure;mechanical property
- 39
- |
- 113
- |
- 0
发布时间：2022-03-15 -
Effect of welding process on the porosity sensitivity of aluminum alloy pulse MIG horizontal welding
摘要：In the welding of aluminum alloy large-scale structural parts,horizontal welding is the most difficult technique. How to reduce weld porosity defects is one of the current research hotspots. The pulsed MIG horizontal welding of 1561 aluminum alloy plates was studied in this paper. The effect of different welding process parameters on the porosity sensitivity was analyzed by X-ray detection and microstructure observation. The results show that the mixture ratio of helium and argon gas in a certain range,the high temperature preheating,the arc tilted upwards,are conducive to gas escaping from molten pool. With the increase of arc voltage and welding speed,it is beneficial to reduce the number of large pores in the weld,and with the increase of welding current,the number of large pores increases. This study can provide a solid experimental basis for the optimization of the welding process for horizontal welding of aluminum alloy.关键词：aluminium alloy;horizontal welding;welding process;porosity sensitivity- 42
- |
- 205
- |
- 2
发布时间：2022-03-15 - 摘要：The effect of heat treatment on residual stress after welding is enormous. For the purpose of analysis of influence law,the welding assembly residual stress subjected to different heat treatment processes are simulated by Sysweld numerical simulation software.It’s composed of tube plate and the annular support plate from the passive residual heat removal system heat-exchanger. Meanwhile,the simulated calculated stress value is compared with the blind hole test stress value,and its mechanical properties are verified by simulation test. The results show that the welding residual stress of the butt weld of the tube plate and annular support plate reduces to the lowest value when it is subjected to stress relief heat treatment at 595 ℃/1.25 h. The minimum stress value is kept constant and the simulated calculated stress value is equivalent to the actually measured stress value level,when the holding time is extended. And the simulated test results also prove that the mechanical properties are at the same level when performing the heat treatment according to different standards.关键词：simulation analysis;heat treatment;residual stress
- 30
- |
- 211
- |
- 4
发布时间：2022-03-15 - 摘要：The grain size of rail flash-butt welding joints affects the wear resistance and mechanical properties of the welded joints.Therefore,for U75 V rails used in high-speed and heavy-duty seamless railways,the average grain size in the temperature of 800～1 100 ℃ and different holding times is measured by an austempering test. The results show that when the temperature is 800～950 ℃,the growth rate of the grains is slow,the average growth rate is about 0.4 μm/min,and the growth speed of the grains accelerates at the temperature of 950～1 100 ℃,and the average growth rate increases and is approximately 1.6 μm/min. A mathematical model of the grain growth of U75 V rail steel under isothermal conditions is established. In addition,the finite element analysis software Abaqus is used to establish the rail flash-butt welding model and the influence of different temperature fields on the grain size of the joint is analyzed,and the simulation results are verified by experiments.关键词：U75V;grain size;flash-butt welding;grain growth model;finite element
- 43
- |
- 123
- |
- 0
发布时间：2022-03-15 - 摘要：Despite that the requirements on the welding technology specification,welder qualification and welding operation for slot welds are defined in D1.1,[Steel Structure Welding Specification] and D1.6,[Stainless Steel Structure Welding Specification] of AWS,there are still cases that the welding operations for slot welds are mixed up with those for groove welds and fillet welds,resulting in quality incidents attributable to defects in slot welds. In view of such problems as development of the procedure for repair of slot welds and the welding operation techniques required,the cases in construction of steel structures and modules at project sites are analyzed,based on the repair of conventional welds,and the technical methods for repair of slot weld are put forward in accordance with the AWS specification requirements,including removal of defects,groove preparation and laying down the welding procedure for repair. And the operation techniques for repair of slot welds in various welding positions are introduced in detail.关键词：slot weld;repair;welding position;welding operation
- 34
- |
- 48
- |
- 0
发布时间：2022-03-15 - 摘要：Filler metals of BNi-2 and BNi71 CrSi were used to vacuum-braze foundry high-temperature alloy K405. The processes of vacuum brazing,mechanical properties and microstructures were compared for the two kinds of filler metals. It resulted that the microstructure of the two kinds of different brazed joints were well. Compared with BNi-2 filler metal,the property of the joint brazed with BNi71 CrSi was higher. In order to ensure the quality of the brazed joint,the gap of vacuum brazing should be less than 50 μm.The test results showed that the design of high frequency hybrid twin-electrode TIG power reached the expected goal.关键词：foundry high-temperature alloy;different filler metals;vacuum brazing;microstructure and property
- 28
- |
- 121
- |
- 1
发布时间：2022-03-15 - 摘要：Using small heat input,9 Ni steel were welded by arc welding with different welding parameters. The microstructure of welded joints were observed,and the tensile,bending,impact,hardness test on weld joints were conducted to study the effects of welding current,voltage and interlayer temperature on the microstructure and bending properties of welded joint. The results show that microstructure of the welded seam is mainly composed of austenite and precipitated phase,there are obvious liquefaction cracks in the welded seam with high welding current and voltage and without controlling the interlayer temperature,and granular bainite is found in the HAZ,the microstructure is composed of lath martensite with low welding current and voltage. The tensile,impact and hardness tests of the welded joints are all qualified with the two welding parameters. The impact energy,plasticity of the welded joints are slightly lower and poor and the hardness values of the HAZ is smaller with high welding current and voltage,and the crack propagates along the heat affected zone and leads to bending fracture with external stress. The welded joints with low current and voltage have good plasticity and qualified bending test.关键词：9Ni steel;HAZ;microstructures;bending test;process parameters
- 26
- |
- 167
- |
- 1
发布时间：2022-03-15 - 摘要：The microstructure and stress corrosion resistance of 6005 A-T6 aluminum alloy joints by friction stir welding were studied using optical microscope,scanning electron microscope and four points bending stress corrosion methods. The results show that the hardness distribution of the joint is W-shape,the lowest hardness appears at the heat affected zone,and the hardness is improved at the weld nugget zone,and the highest hardness appears at the base metal. The main strengthening phase of the base metal is Q’ phase,most of which is disappeared at the weld nugget zone,and where exists lots of dislocation and the main strengthening mechanism is fine grain strengthening,dislocation strengthening and solid solution strengthening. Friction stir welded joint shows good stress corrosion resistance,however corrosive pitting is also happened,and the weakest part of the welded joint is in the heat affected zone.关键词：6005A-T6 aluminium alloy;friction stir welding;precipitated phase;microstructure;stress corrosion
- 45
- |
- 174
- |
- 6
发布时间：2022-03-15 - 摘要：Laser welding research is carried out on aluminum bronze materials,and the microstructures and mechanical properties of the welded joints are analyzed. The experimental results show that the laser welding of Al-bronze has good forming,no obvious defects exist on the weld surface. The weld penetration width and depth increase with the increase of laser power density,and decrease with the increase of laser scanning speed. The defocusing amount has little effect on the penetration width,but has a great influence on the penetration depth. Microstructure analysis of the weld shows that the microstructure of the weld is mainly cellular crystal,and the grain size at the weld is obviously refined. The average hardness of the weld is 60% higher than that of the matrix materials.关键词：laser welding;aluminum bronze;microstructure;mechanical properties
- 29
- |
- 111
- |
- 2
发布时间：2022-03-15 - 摘要：The pump cover of nuclear high temperature liquid metal pump is made of 316 austenitic stainless steel for nitrogen control.The welded joints have the characteristics of large thickness,large diameter,large welding filling and high mechanical properties. It is not only difficult to ensure the welding quality and mechanical properties of joints but also low welding efficiency and high labor intensity of welders by other methods. The welding efficiency is improved,the welding quality is guaranteed and the welded joints with excellent comprehensive mechanical properties are obtained by using a special developed submerged arc welding wire of φ2.4 mm and matching flux,combining with narrow gap groove and reasonable welding parameters. It provides an effective reference for the manufacture of similar products.关键词：austenitic stainless steel;narrow gap;fine wire submerged arc welding
- 29
- |
- 92
- |
- 2
发布时间：2022-03-15 - 摘要：A flux cored wire 2209 for duplex stainless steel was developed and different weight percent of content of CaF2 were added in it. The microstructure of slag was observed by Olympus-PMG30 and the gas porosity rate on the weld was tested. The results showed that when the weight percent of CaF2 were less than 2%,the contents of "FeO" decreased with increasing of the content of CaF2,which are beneficial to the detachability. If the weight percent of CaF2 was more than 3%,the detachability of the slag became more compact which could worsen the detachability of slag. In addition,the processing properties become deteriorated. With increasing of the content of CaF2,the gas porosity reduced.关键词：duplex stainless steel;flux cored wire;slag detachability;gas porosity
- 33
- |
- 75
- |
- 0
发布时间：2022-03-15 - 摘要：Experiment of automobile front crash indicates that the rail is the most important component to absorb impact energy. Not only the size and material can affect energy absorption of the rail,but also the quality and the distribution of the spot welds can have important influence. A research on impact of front rail by computer simulation is carried out in this paper. A Monte Carlo simulation method is used for generating the statistics distribution function of spot welding location in the front rail. The effects to the collapse mode and energy absorption are analyzed. The results show that corresponding to the variation of spot weld location,the difference in energy absorption can be more than 8%. The deformation mode of the front rail is also strongly affected.关键词：spot welding;the front rail;Monte Carlo;crash simulation
- 27
- |
- 42
- |
- 0
发布时间：2022-03-15 - 摘要：The welds of swivel arm positioning seat have some defects of incomplete fusion,undercut,unmanageable welding deformation and low production efficiency. Through analyzing the structural features of swivel arm positioning seat,the welding parameters and welding sequence are optimized. The results show that the optimized welding procedure effectively solves the welds quality problems,no need for repair and adjustment after welding. This method saves a lot of labor cost and production cost,and greatly improves the production efficiency.关键词：bogie frame;welding;quality control
- 38
- |
- 33
- |
- 0
发布时间：2022-03-15 - 摘要：If railway vehicles run fast and smoothly, the bogie frame is the most important bearing part. The quality of the bogie frame directly affects the operation safety of train. The existing welding technology of railway vehicles beam,side beam and bogie frame are introduced and improved. By changing the welding sequence of beam,side beam and bogie frame,the welding modularization is realized. By guaranteeing the accuracy of welding and postweld repair method,the processing quantity of all parts on the bogie frame is within the tolerance range,and the phenomenon of repair welding is eliminated.关键词：railway vehicles;bogie frame;modular welding;repair welding
- 45
- |
- 33
- |
- 2
发布时间：2022-03-15 - 摘要：EAM336-F12 is a new type of material based on the ASME SA336 Gr.F12 forging standard for nuclear power main steam pipeline,which is manufactured by the electro-fusion additive technology. In order to master the welding process of the material,this research is carried out. Through the carbon equivalent analysis method,this paper analyzes the hardening tendency and cold crack sensitivity of this material and determines the preheating temperature before welding,and through the weldability test respectively under the welding and post-weld heat treatment states in welding joint for tensile,bending,impact mechanical properties test,the chemical composition test analysis and metallographic examination test at the same time,the test results meet the ASME SA336 Gr.F12 performance requirements,show that this material has good weldability.关键词：EAM336-F12;electro-fusion additive technology;carbon equivalent;weldability
- 35
- |
- 63
- |
- 0
发布时间：2022-03-15 - 摘要：During the winding process of aluminum foil used in the lead wire loop,aluminum foil needs to be welded. Because the aluminum foil is extremely thin（about 0.25 mm）,using conventional welding methods such as MAG and TIG will be easy to burn through the base material and is difficult to form an effective welded joint. In this paper,a ultrasonic welding method is used and a complete set of welding technology is selected from the parameters of welding amplitude,welding pressure,welding time and so on. A number of welding samples are made,and the reliability of the welding quality of aluminum foil is comprehensively analyzed by the test methods of welded joint,such as mechanical property,scanning electron microscope and microscopic metallographic test. The results show that the ultrasonic welding of aluminum foil is feasible,and this welding technology can obtain the welded joints that meet the design requirements.关键词：aluminum foil;ultrasonic;welding technology;welded joint test
- 48
- |
- 159
- |
- 1
发布时间：2022-03-15 - 摘要：A new high-quality, high-efficient and low consumption welding method with nonconsumable electrode is put forward,and a high frequency hybrid twin tungsten electrode TIG power source is developed,which can output two types of current waveforms simultaneously. One is high frequency square current waveform with base current of 0～300 A,peak current of 0～400 A,frequency of 0～80 k Hz,duty ratio of 0～100%,current rate of change of 50 A/μs. The other is variable polarity square wave pulse current waveform with output current amplitude of 0～500 A,frequency of 0～100 Hz,duty ratio of 0～100%,current rate of change of 300 A/ms. The parallel main circuit topology and DSP+ SG3525 A control system mixed with analog and digital IC is adopted. Through software programming,the sync-output of welding current given signal and PWM signal is realized,which can realize high frequency square wave pulse current and variable polarity square wave pulse current output at the same time. The test results show that the high frequency hybrid twin tungsten electrode TIG power source achieves the expected design goal.关键词：high frequency;twin tungsten electrode;square wave pulse;variable polarity;argon arc welding
- 35
- |
- 161
- |
- 1
发布时间：2022-03-15 - 摘要：Based on the application of robot welding workstation in automobile parts manufacturing,a workstation solution for multiple welding jig is put forward. The efficiency and operational capability of the whole system are improved by means of layered control.Based on the theory of synchronous control,a control strategy for dual robots coordinated welding is developed. A free compiling system consisting of a large number of structures and arrays is developed to be compatible with many different types of jigs. The industrial control system is constructed by the main controller. The monitoring and early warning of running status of workstation is realized by using human-computer interaction interface and on-site detection equipment.关键词：ccoordinated control;free compiling;universal;ethernet
- 31
- |
- 49
- |
- 0
发布时间：2022-03-15 - 摘要：Beijing TIME Technologies Co.,Ltd. makes use of rectangular coordinate robot to carry submerged arc welding system for welding large structural workpieces,which has effectively improved the welding efficiency, reduced the work intensity and improved the welding quality. We solved the difficulties of integrating submerged arc welding system with Robot,and achieved good application results. The rectangular coordinate robot consists of a mechanical body,a robot controller and a welding system. The mechanical body consists of three linear axes and one rotating axle. The robot controller uses X86 industrial computer as hardware platform,and uses IEC61131-3 standard industrial control programming language to write control software to realize motion control algorithm and HMI.关键词：rectangular coordinate system;robot;submerged arc welding
- 26
- |
- 220
- |
- 1
发布时间：2022-03-15 - 摘要：With the development of arc welding inverter to high frequency and high power density,the influences of parasitic parameters become more critical with the high voltage and current slew rate. Modeling of power semiconductor modules in the absence of data of chip technology and electrical parameters is common problem for system designer. To solve this problem,a high efficiency and practical method for extracting parasitic parameters inside packaging is presented. Splitting interconnect conductors based on the principle of partial element equivalent circuit,PEEC. The numerical calculation of quasi-static electromagnetic field is carried out for one unit with the same geometric structure using ANSYS Q3 D. Parasitic inductance and resistance parameter matrix is extracted. By merging and reducing equivalent circuit,the complete module model including parasitic inductance,resistance and capacitance is built. The parameters of the model are provided for an IGBT module of SKM200 GB125 D as an example. Using double pulse test method,the switching behavior is simulated and measured. The accuracy of the model and validity of the modeling method is verified by the comparison between the simulated and experimental results.关键词：high frequency;parasitic parameters;partial element equivalent circuit PEEC;ANSYS Q3D;double pulse test
- 51
- |
- 231
- |
- 6
发布时间：2022-03-15 - 摘要：Robotic welding is usually used in the mass production of standard components,but it is not well applied in the small batch production of non-standard components due to the long teaching time when components change. With the increassing demands of automation in the heavy industry,modular design is conducted for shield structure,which a large non-standard product in shield tunneling machine,by taking advantage of automatic characteristics and flexibility of robotic welding station. Working modular is established according to the structure features and dimensions,which is then optimized to different robotic welding stations,namely tailor blank welding and assembly station for body of shield structure and multiple robotic welding stations for component. In such a way,the production line of shield structure is upgraded to manufacture automatically and in module. The production efficiency and quality are greatly improved. It can provide a paradigm for upgrading the manufacturing of such large non-standard products.关键词：robot;modular production;automatic upgrading;large non-standard product
- 29
- |
- 84
- |
- 2
发布时间：2022-03-15 - 摘要：In this paper,the ultrasonic scanning detection method of carbon fiber reinforced composite（CFRP） joints in the bogies of electric vehicles is studied. The defect information is collected by ultrasonic C-scan method,and a manual ultrasonic imaging detection system is established for carbon fiber reinforced composite connectors,which avoids the technical drawbacks of poor adaptability of conventional ultrasonic automatic scanning imaging to irregular surface structures,and makes the detection process real-time,fast and flexible. Based on the KSW entropy method,a geometric model is established and two three-dimensional models are built. The defect coverage area and the defect coverage rate are obtained by the computed program. The visualized defect detection in the three-dimensional image of the component is realized,which avoids the naked eye observation in the conventional method and improves the reliability of the detection results.关键词：carbon fiber composites;joint structures;ultrasonic scanning;defect detection
- 30
- |
- 332
- |
- 4
发布时间：2022-03-15 - 摘要：Welding is the most important work of steel structure construction in ocean engineering project,and the welding qualification rate is the key problem of construction. Welding defects will lead to repair,and the repair will not only delay the construction period and increase the project cost,but also will have a certain impact on the performance of the welded joint. Through the analysis with fishbone diagram,we concluded that the main reason for the welding defect is the welder itself. Most of the welding defects are due to the welders who welded not in accordance with the welding process which was specified by project. Regularly calculating the welding qualification rate,and punishing the welders who with a low welding qualification rate,which can effectively make the welders more conscientious in their welding work,thus reducing the welding defects.关键词：welding qualification rate;weld defect;qualification rate statistics
- 22
- |
- 38
- |
- 0
发布时间：2022-03-15 - 摘要：<正>各位作者:为确保杂志质量,尊重和保护作者和他人知识产权、著作权,根据国家期刊出版管理的相关规定,《电焊机》杂志特作以下申明。1.作者应保证是向本刊所投稿件的著作权人,不得抄袭、剽窃、盗用他人科研成果、文章和信息。文章中引用和参考他人文章、著作和成果（包括网络信息）时,按编辑出版规定,应在文章中以参考文献方式明确标识。如作者的文章涉及侵犯他人知识产权、著作权等合法权益时,一切后果文责自负。2.作者所投稿件应保证尚未在其他媒体（包括网络）出版或发表,也未向其他媒体投稿。
- 25
- |
- 7
- |
- 0
发布时间：2022-03-15
- Postal code：610051
- Tel：028-83289008
- Technical support is provided by Beijing Founder electronics co., LTD 蜀ICP备07004068号-2
公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0