最新刊期
期 3 ， 2020
- 摘要：Extreme high-speed laser material deposition is a new type coating technology. It optimizes the fusion-solidification mode and power absorption by modifying the relative positions of laser light,spray powder and molten pool,thus the deposition speed rate is improved,and a high quality coating, which is free of defects and has high bonding strength as well as low dilution rate,is obtained. Extreme high-speed laser material deposition possesses unique advantages comparing with the other coating technologies,including hard chrome plating,thermal spraying,conventional laser cladding and welding. This paper details the technical features and advantages of extreme high-speed laser material deposition processing,summarizes the research conditions of this new technology,including processing parameters,microstructures,properties and industrial application. An outlook of future development about extreme high-speed laser material deposition is given. It is pointed out that a lack of fundamental mechanics studies about coated components has hindered the application of this new technology.关键词：extreme high-speed laser material deposition;depositiontechniques;greenmanufacturing;coatings
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发布时间：2022-03-15 - 摘要：CAP1400 nuclear power plant CV module steel plate（SA-738 Gr.B） has a small gap and automatic welding with a small filling volume and high welding efficiency. First a single variable experiment is conducted to study the influence of parameters such as swing speed,sidewall dwell time,welding current,welding speed,and the distance from the tip of the wire to the sidewall on the weld penetration depth,residual height,and sidewall penetration depth in a narrow gap groove,with a special narrow gap welding gun. The results show that in a narrow gap bevel,the swing speed has the greatest effect on the penetration of the weld;the welding current and the welding speed have the greatest effect on the remaining height;the distance from the tip of the wire to the side wall has the largest effect on the penetration,and determined the optimal welding parameter range. Second,the optimal parameters are used to weld the test plate,and the test plate is tested for mechanical proper-ties. The results show that the tensile properties and impact properties are higher than the requirements of the base metal.The study provides theoretical basis and reference for the further engineering application research of CV narrow gap automatic welding process.关键词：SA-738 Gr.B;welding process parameters;narrow gap groove;swing arc
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发布时间：2022-03-15 - 摘要：3D printing is a new material forming process in recent years,which is so attractive due to its high efficiency and materials saving. However so far there is a big challenge on how to control the microstructure meeting the requirements of mechanical properties, especially under the complex loading for the super-size parts. The selection of parameters in process has a remarkable impact on the final performance of the product. This paper prepared a super-size TC4 titanium alloy blades with a length of 1 450 mm by 3D printing process. The chemical composition was analyzed and the microstructure was observed. Furthermore,the correspon-ding mechanical properties were carried out. It was discussed for the microstructure to affect the properties. The results showed that the large diameter of the light spot and the improper heat treatments were used in the molding process, which made the microstructure o f the blade unevenly and resulted in the mechanical properties decreasing for the blade. In addition,the anisotropy of the mechanical properties existed in the 3D printed blade. This research is of great significance in promoting 3D printing to engineering application.关键词：3D printing;titanium alloy;super-size blade;microstructure and mechanical
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发布时间：2022-03-15 - 摘要：An on-line detection method of line energy is proposed for the problem that the welding line energy can not be accurately measured in real time in the manual welding process. A flexible arc light capturing mechanism is designed,which can adapt to different beads in all position manual welding. The conversion technology from arc light signal to electrical signal is emphatically studied,and then a signal processing system with STM32 single chip microcomputer as the control core is built to realize the realtime display of digital quantity of welding line energy. The welding test shows that the method has good real-time performance and the detection precision meets the requirements.关键词：welding line energy;all position welding;online detection;STM32 MCU
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发布时间：2022-03-15 - 摘要：The reasonable design of forced air cooling and heat dissipation for inverter welding machine is conducive to improving the reliability of the whole machine and prolonging the service life of the equipment. Combining with an example,the theoretical calculation method of IGBT module heat dissipation design of inverter welding machine under forced air cooling is put forward, and the simulation analysis and test verification are carried out on the calculated results. The results show that this calculation method can meet the design requirements,and can provide technical reference for heat dissipation design of high-power products such as electric welding machine.关键词：inverter welding machine;forced air cooling;heat dissipation design
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发布时间：2022-03-15 - 摘要：LabVIEW has the characteristics of graphical programming language,short development cycle and low diffi-culty. Under the development environment of LabVIEW and combining with the data acquisition card of NI company,the double pulse MIG welding system is built,which can collect the current,voltage and control output and display the double-pulse waveform in real time. Several sets of double pulse experiments were designed to verify the feasibility of double pulse MIG welding system. The results show that the double pulse MIG welding system based on LabVIEW can meet the welding requirements,and the welding process is well,and a good fiscal-scale weld can be formed.关键词：LabVIWE;double pulse MIG welding;welding parameters
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发布时间：2022-03-15 - 摘要：For the underwater operation requirements of installation,Installation,fixation,plugging and maintenance in marine engineering,an underwater stud welding gun is designed based on short-period arc welding technology. The research and development of underwater stud welding gun is introduced from the perspectives of waterproof,electrical safety and easy operation. The water tightness test,gas supply and drainage test and underwater welding test are carried out for underwater stud welding gun. The results show that the under-water stud welding gun has good waterproof performance,safe and reliable operation,and can realize the rapid underwater welding of the stud.关键词：stud welding;underwater welding;welding gun
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发布时间：2022-03-15 - 摘要：With the air pollution caused by automobile exhaust is increasingly severe,the government plans to carry out G6 emission standards for fuel vehicles. Comparing with the previous G5 emission standards,the new G6 emission standards have a lot of improvement in exhaust purification index. Therefore,the structure characteristics of the G6 exhaust products are quite different from those of the G5 exhaust products. The robot welding exhaust production line of the G6 emission standards are also quite different from those of the G5 emission standards.The characteristics of the exhaust products,the composition of robot welding production line,the selection and characteristics of robot welding work station,and the types and characteristics of handling equipments and welding inspection equipments for G6 emission standards are expound to provide some reference for the planning of robot welding production line with commercial vehicle G6 emission standards.关键词：commercial vehicle G6 emission standards;robot welding work station;handling equipments;welding inspection
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发布时间：2022-03-15 - 摘要：Mn-N duplex stainless steel surfacing samples were prepared by powder surfacing and solution heat treatment.The metallographic structure of the surfacing layer was observed.The corrosion resistance of the surfacing layer was studied by the ferric chloride immersion experiment and the polarization curve method,and was compared with the surfacing layers of 2209 duplex stainless steel and 304 austenitic stainless steel respectively. The results show that the metallographic structure of the self-made Mn-N duplex stainless steel surfacing layer is austenite and ferrite,and the two-phase ratio is close to 1:1. The presence of ferrite provides sufficient Cr for the grain boundary and reduces the carbon precipitation of Cr,and the pitting resistance is better than 304 austenitic stainless steel;the corrosion resistance of Mn-N duplex stainless steel is slightly worse than that of 2209 duplex stainless steel,the reason is that its chromium and molybdenum are lower than those of 2209 duplex stainless steel,which reduces the stability and repassivation ability of the passivation film.关键词：surfacing;Mn-N type duplex stainless steel;corrosion resistance
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发布时间：2022-03-15 - 摘要：In recent years,with the further development of China’s nuclear power manufacturing technology,the field of repairing and remanufacturing of China nuclear power equipment has also developed significantly. Some new special welding technologies are continuously developed and innovated and have successfully been applied in the repairing and remanufacturing market of the core components of 1 000 MW nuclear power steam turbines in China. It is proved that highenergy beam welding technology based on high-speed or ultra high-speed laser melting depositing and micro-plasma transfer ring arc welding have a wide application;cold metal welding（abbr. CMT） still has a strong adaptability;and instantaneous transfer welding based on high-frequency cold welding technology still has wide advantages in repairing small defects of precision components. The intelligent remanufacturing technology with high-energy beams as the heat source based on robot 3D printing technology will be a mainstream trend in the future nuclear power repair market. Meanwhile, the corresponding industry guidelines or standards for nuclear component repair should also be timely upgraded with the continuous development of special welding technologies to promote the continuous development of industry technology.关键词：special welding technology;nuclear power steamturbine;repairing;remanufacturing
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发布时间：2022-03-15 - 摘要：The performance of weathering steel for fabricated building was studied by thermal stimulation technology. The results show that coarse-grain heat affect zone（CGHAZ）,which gets the highest hardness and the poorest impact toughness,is most possible to became the weak areas of welded joint. With increasing of heat input,the microstructure of CGHAZ changes from lath bainite to granular bainite,and the hardness decreases. The impact energy increases at the beginning and then decreases. The maximum impact energy reaches 236 J when heat input is 15 kJ/cm.The fracture behavior of those specimens are further analyzed by observing fracture morphology and section microstructure of those impact specimens. When heat input is too low,more quenchinghardening structure,which get little small plastic deformation during fracture process,is formed,and impact toughness is poor.When heat input was over 20 kJ/cm,the ability of preventing crack propagationdecreasesandimpacttoughnessdecreases.关键词：fabricated building;thermal stimulation;heat input;CGHAZ
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发布时间：2022-03-15 - 摘要：The welding cracks on the surface of external nozzle and surfacing layer of hydrogenation reactor were found when it was installed in the field. The causes of cracks were analyzed by means of macro inspection,magnetic powder test,penetration test,chemical composition analysis,metallographic structure analysis,hardness test and ferrite content test. The analysis showed that the external nozzle cracks were mainly welding cold cracks and the other were welding heat cracks. Most of the cracks in surfacing layer were linear（strip） cracks,and some of them were mesh cracks. The characteristics of these cracks were welding heat cracks. The main cause of cracks was improper welding process. Through the development of corresponding solutions,the cracks were successfully repaired,and the prevention suggestions in the manufacturing process of the hydrogenation reactor were proposed.关键词：hydrogenation reactor;welding heat crack;solution
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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） in air and water respectively using the same welding parameters.The effects of different cooling media on the thermal cycle curve,macro morphology,microstructure,hardness and mechanical properties of the welded joint 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 better formed than that of welding in air. The grain of underwater joint is finer and the heat affected zone is narrower with clearer plastic manifold. The heat affected zone of welded joints in air softens seriously,and the hardness is only 113 HV. The fracture form of underwater welded joint is brittle rupture,while the fracture form of welded joint in air is ductile fracture.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：Welding consumables developed for the new austenitic heat-resistant steel HR3C include YT-HR3C and Ni-based consumables,the Ni-based consumables include ERNiCrCoMo-1,ERNiCr-3 and ERNiCrMo-3. It needs to strictly control the welding process in order to prevent thermal cracks during welding,the key is to control the interlayer temperature of welding ≤100 ℃,with aging time at different temperatures,the weld structure of the welded joint have no change,is single austenite structure（γ phase）,but the number,morphology and distribution of precipitated phases Cr23C6,CrFe7C0.45,（Cr,Fe）7C3,CrNbN and Cu-rich phases change,a large amount of precipitation of Cr23C6 leads to a sharp decline in the impact energy of the joint,behave aging embrittlement.This article mainly reviews the research development on welding consumables,welding processes and weld joint performance of HR3C.关键词：austenitic heat-resistant steel;HR3C;welding;aging embrittlement
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发布时间：2022-03-15 -
Application of phased array ultrasonic technology in weld detection of high-speed bullet train bogie
摘要：Combining the structural characteristics of the CRH3 series high-speed bullet train frame products,the difficulties in internal inspection technology for key weld of sluice bracket hanger of CRH3 series bullet train are analyzed.An ultrasonic phased array testing technology scheme is verified through experiments, and some reasonable suggestions are put forward for the improvement of the design structure of sluice bracket hanger. The phased array ultrasonic testing of the weld is carried out and verified in practical testing, and all kinds of defects in the weld can be detected accurately. The application of phased array ultrasonic technology in this weld inspection is studied,and the full coverage of this weld inspection is realized to guarantee the quality of weld.关键词：high-speed bullet train;phased array ultrasonic;weld;defect- 31
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发布时间：2022-03-15 - 摘要：Twin-electrode gas tungsten arc（TE-GTA）welding is applied to clad stainless steel on low alloy steel. The dilution rate, microstructure,type II boundary, martensite zone of the welds are analyzed. The chemical composition,hardness,impact and inter-granular corrosion of surfacing layer are tested. The results show that as the heat input increases,dilution rate and grain size increase, type II boundary migrates further,and the martensite zone grow larger. When the heat input is constrained,the mechanical performances of TE-GTA welds are similar to those of single GTA. But when the heat input is excessive,the weld performances obviously deteriorate.关键词：twin-electrode gas tungsten arc;stainless steel surfacing;microstructure and performances
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发布时间：2022-03-15 - 摘要：The procedure optimization of seam welding for titanium plate and stainless steel mesh is described,and the effects of the fracture mechanism of mesh,seam welding pressure and energy input in welding process on stainless steel mesh are mainly studied. The results show that there is a "twice" seam welding process in the weld,the titanium plate and stainless steel mesh produce brittle intermetallic compounds in the first seam welding process,and in the second seam welding,the large pressure and large welding heat input lead to mesh break;when using smaller seam welding pressure and smaller welding heat input,and under the premise of ensuring qualified weld tear test,the mesh fracture probability can be effectively reduced;through preferred test, ultimately preferred a low pressure seam welding parameters are:seam welding electrode pressure of 0.08 MPa,welding current of 900 A,seam welding speed of 2 r/min;the preferred seam welding parameters are used in straight and circular seam weld test pieces,and the pass rate is 85% and 90% respectively.关键词：titanium plate;stainless steel mesh;seam welding;pressure
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发布时间：2022-03-15 - 摘要：In order to obtain the change law of surface morphology of aluminum alloy after laser cleaning,a laser with pulse width of 150 ps was used to clean the oxide film on the surface of aluminum alloy. The surface morphology,micros-tructure,composition and roughness of the laser-cleaned aluminum alloy were observed and tested by optical microscope,scanning electron microscope,energy spectrometer and roughness meter. It is found that after laser cleaning,the oxygen content and roughness of the surface of aluminum alloy decrease,and the oil and oxide film are washed off, forming regular cleaning traces,which are composed of tidal tissues and tiny particles. When the energy density is greater than 1.53 J/cm2,the surface temperature of the aluminum alloy is high,and the generated plasma gas impacts the surface of the micro-melted aluminum alloy,making the trace deeper and increasing the area and time of contact between oxygen in the air and high-temperature aluminum alloy,thus resulting in a more severe oxidation phenomenon, so that the laser cleaning traces and secondary oxidation phenomenon of the aluminum alloy surface increase when the energy density increases.关键词：laser cleaning;aluminum alloy;morphology;roughness
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发布时间：2022-03-15 - 摘要：Aiming at the problem of low qualified rate of high temperature alloy bracket welding,a Six Sigma project was launched. Through the five stages of definition,measurement,analysis,improvement and control,the welding process flow is analyzed,the potential factors affecting the weld quality are determined,and the key factors are determined through the two methods of double ratio test and chi square test. Finally,through the design test,the key process parameters are optimized and the optimal process parameters are determined. When the improved process plan is applied to the actual production,the welding qualification rate is increased from 35% to 95.8%,and the annual scrap and repair cost is saved by 627000 yuan. This paper proves the feasibility of Six Sigma method in the field of welding and provides reference value for the production and improvement of similar products.关键词：Six Sigma;high temperature alloy;welding;processimprovement
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发布时间：2022-03-15 - 摘要：Liuhua16-2 FPSO is one of the most challenging projects in Offshore Oil Engineering Co.,Ltd.,the most important part of FPSO is single-point mooring system. It is significant to guarantee the fabricated accuracy of both the single-point mooring system and the moon pool so as to they can match each other with high precision in integration phase.This paper expounds the dimensional control method of moon pool and single-point mooring system by using the point cloud data acquired with 3D laser scanner which is creative application in this field.关键词：FPSO;point cloud data;SPM integration
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发布时间：2022-03-15 - 摘要：The laser additive TA15 powder test was carried out on TC6,the tensile strength of samples was measured after additive repair with WDW-100 testing machine,the impact toughness of the repaired sample was measured with an impact toughness testing machine. The optical microscope（OM） and scanning electron microscope（SEM） were used to observe and analyze the microstructure of the joints. Research indicates that the TC6 damaged laser additive repair joint is well formed,and there are no cracks or pores at the joint interface joint. The tensile strength of the joint can reach 1 000 MPa,the impact toughness can reach 27.5 J/cm2,and the specimen breaks in the heat affected zone near the TC6 base metal. The best process parameters of TC6 laser deposition were that the laser deposition powder was TA15 powder,the laser power was 1 400 W,the scanning speed was 0.01 m/s,the powder feeder reading was low%（English）,the powder carrier gas was 8 L/min,the overlap rate was 40%,the spot diameter was 2 mm,the height of single cladding layer 0.3 mm. The TC6 laser deposition joint consists of weld zone,fusion zone,heat affected zone,and base metal. The weld zone was mainly fine acicular martensite;the semi-melted grains in the fusion zone were mainly β columnar crystals grown by substrate epitaxy;and the fusion zone was composed of coarse columnar crystals,the crystal grains grew in a upside down V shape;the heat-affected zone was mainly α’ lamellar martensite.关键词：TC6;TA15 powder;HAZ;fusion zone
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发布时间：2022-03-15 - 摘要：For the Lusail Stadium project,this article states the QA/QC quality management of this project at the time of factory production,we developed a project inspection and testing plan ITP,which also described specific requirements of personnel qualification,material management,project inspection,etc. At the same time,the typical column foot node is taken as an example to carry out key process research. Based on the research of manufacturing technology,small angle welding technology,large section end milling and wide-angle groove open technology,etc. We can achieve the quality control requirements of this project component.关键词：QA/QC quality management;ITP;process research
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发布时间：2022-03-15 - 摘要：Effect of laser on metal transfer and welding process stability were studied. The results show that laser-MIG hybrid welding process was more stable than MIG. When wire feeding speed were low,electromagnetic force,plasma drag force and recoil force induce by the metallic vapor from the keyhole of laser were the keys to affect the droplet behavior.The landing location of droplet in laser-MIG hybrid welding was closer to the welding filler wire due to the effect of the recoil force induce by the metallic vapor from the keyhole of laser. When wire feeding speed was high,electromagnetic force and plasma drag force were the keys to affect the droplet behavior. The droplet behavior of laser-MIG hybrid welding and MIG welding had no significant differences.关键词：MIG welding;laser-MIG hybrid welding;metal transfer
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发布时间：2022-03-15 - 摘要：J-shaped groove is one of the commonly used groove forms in the weld of railway vehicle bogies. Q345 steel is one of the materials used in the railway vehicle bogies. For the J-shaped groove weld of Q345 steel,the technological research on the three methods of manual,automatic and hybrid MAG welding is studied. By comparing the test results of the macroscopic metallurgy and hardness of the welded joints,it shows that the hybrid MAG welding is more efficient than the manual MAG welding,and the weld quality of hybrid MAG welding is better than that of automatic MAG welding. So hybrid MAG welding is the most suitable procedure for meeting the basic requirements of batch safety production.关键词：bogie;J-shaped groove;hybrid MAG welding;technological research
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发布时间：2022-03-15 - 摘要：One of the welding characteristics of aluminum alloy materials is that it is easy to produce gas pores. The existence of a large number of gas pores may not only reduce the strength of effective section of the weld,but also cause the damage of the welding structure and affect the service performance of the weld. There are many factors for the generation of gas pores in aluminum alloy welds. In this paper,through the welding tests of plates at different welding positions under the condition of fixed welding parameters, the relationship between the gas pore sensitivity of MIG welded joint of 5083 aluminum alloy and welding position is analyzed combining with the X-ray nondestructive testing results,and the distribution law of gas pore in the weld is summarized. The results show that under the same condition,the gas pore sensitivity is the highest when welding at horizontal position of welding. This is because at horizontal position of welding,arc is not straight to the molten pool,the pool is heated unevenly,and the stirring effect of arc on molten pool is weak.Appropriately optimizing welding para-meters and controlling environment can improve the sensitivity of welding gas pore and the welding quality reliability.关键词：aluminium alloy;MIG;gas pore
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发布时间：2022-03-15 - 摘要：Chongqing Pump Factory used carbon dioxide arc welding and solid core wire for surfacing welding,the cladded layers have lots of weld defects. Welding process experiment were made by MAG welding technique and solid core wire,where the materials of transition layer and anti-corrosion layer were ER309L and ER308L solid stainless steel welding wires,respectively. PT performance,bending and electrochemical corrosion performance were studied. The microstructure of joint were observed and analyzed,which compare with the property of using flux-cored wire to surface.The results show that the cladded layers have good fusion with the base steel without crack,gas cavity and other defects. The welding efficiency is higher,and its bending and electrochemical corrosion properties are good. Microstructure of anti-corrosion layer is dendritic austenite.关键词：MAG welding;solid core wire;microstructure and property;electrochemical corrosion
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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、异种材料激光焊接技术、新材料和异种材料激光焊接和工艺规程、激光焊接与切割在汽车制造、航空航天、工程机械、电力、高铁、石油天然气管道、电力、锅炉、核能等领域的应用
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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>书号:0226售价:38.00元本教材以焊接结构制造工艺过程为主线,全面论述焊接结构制造中的工艺规程编制、备料加工、装配焊接及装备、典型焊接结构的制造技术、质量控制与检测、焊接生产环保和安全等五大板块,共8章。本教材较全面地反映了焊接结构制造的新技术、新方法和新装备。本教材可作为普通
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发布时间：2022-03-15 - 摘要：<正>书号:0095定价:16元焊接操作中存在诸多危险因素和有害因素,可能发生触电、火灾、爆炸、灼烫和高处坠落等工伤事故,还可能患眼睛、皮肤、呼吸系统和血液等疾病。因此,焊接属于特种作业,电气焊工属于特殊工种,遵照国务院颁布的有关规定,焊工必须经过安全培训并考试合格,方准独立操作。并且在取得安全考核合格证之后,尚需定期参加复审。焊接安全与卫生防护的教学内容繁多,涉及的理论知识范围甚广,本书是根据国务院1963年
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发布时间：2022-03-15
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