最新刊期
期 3 ， 2021
- 摘要：High efficiency,short process and integrated forming of complex precision metallic parts are of great significance to the structural optimization and cost reduction of advanced aircrafts. In this work,the structural design optimization and processing adaptability of AlSi10Mg alloy thin-walled metallic components for new aircrafts were performed using selective laser melting（SLM）. The influence of laser power,hatch spacing,shielding gas and heat treatment on the manufacturing quality was discussed in details. The results show that under a set of optimized processing parameters,AlSi10Mg alloy formed by SLM shows a dense structure and fewer pores,and its deposited tensile properties at room temperature are superior to those of castings. The internal and surface qualities of the obtained parts are also good,and the geometry accuracy of the side walls after heat treatment is within 0.2 mm,which meets the assembly design requirements of complex new aircraft parts.关键词：additive manufacturing;AlSi10Mg alloy;aircraft structure;tensile properties;geometry accuracy
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发布时间：2022-03-14 - 摘要：Stereolithograph apparatus（SLA）,as one of the additive manufacturing technologies,was combined with the investment casting to produce metal lattices with sub-millimeter diameter trusses. The process optimization results show that the best parameter is 4.52 s of the single layer forming time with a single layer thickness of 50 μm. The stereolithography is used to create a sacrificial scaffold that is embedded in the invest-ment matrix with subsequent sublimation to create a system of 750 μm pores that are filled with ZAMAK3 alloy during casting.The metal lattices are created with two alternative approachesspin casting and gravity casting（with vacuum assist）. Compression testing of lattice structures demonstrates that two casting technologies produce metal lattices with comparable mechanical strengths,and the bearing pressure load is 1.24 k N and 1.30 k N respectively. The simulation results of finite element analysis are closer to those of centrifugal casting,when the deformation is more than 0.6 mm,the simulation results of finite element begin to deviate from the actual deformation.关键词：metal lattice structures;additive manufacturing;stereolithography;investment casting;micromanufacturing
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发布时间：2022-03-14 - 摘要：It is important to define the quality grading and inspection strategies in the standards of metal components using additive manufacturing,which determines the use grade and occasion of metal components. At present,the general practice of quality inspection of additive manufacturing standards in China’s current aviation industry is using the testing standards of the same material’s forgings to stipulate the quality level of additive manufactured components,which generally requires Grade A or Grade B. However,the current standards for metal components using additive manufacturing don’t explicitly stipulate the quality levels,and basically depend on one of quality grade of ultrasonic testing and lack corresponding grading requirements for X-ray inspection. Therefore,the current additive manufacturing standards of aviation industry need to be further improved. By comparing current standards for fabrication of metal components using additive manufacturing related with National Standards（GB）,aviation industry standards（HB）,national military standards（GJB）, international standards（ISO）,American Society for Testing Materials standards（ASTM）,International Association of Automation Engineers standards（AMS）and the American Welding Society standards（AWS）,the current quality classification and inspection strategies of metal components using additive manufacturing domestic and foreign was analyzed. Different quality classification and inspection strategies were reviewed briefly. The similar connotation of quality classification and inspection in AWS D20.1/D20.1 M:2019《Specification for Fabrication of Metal Components using Additive Manufacturing》and AWS D17.1/D17.1 M:2017-AMD1《Specification for Fusion Welding for Aerospace Applications》was expounded. Some suggestions on the quality classification and inspection strategies of metal components using additive manufacturing for China’s aviation industry were discussed and put forward.关键词：additive manufacturing;metal component;quality grading;quality inspection
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发布时间：2022-03-14 -
Study of abrasive wear behavior of Fe-C-Mo-V hardfacing alloys in rolling three-body abrasive system
摘要：Fe-C-Mo-V hardfacing alloys wear samples are prepared by GMAW welding technology. Dry sand abrasive wear tests are carried out based on the rolling three-body abrasive environment,and scanning electron microscope,energy spectrum analysis,Vickers hardness tester and other microscopic analysis and performance testing methods have been used to detect and characterize the wear loss and wear scar morphology of the FeC-Mo-V hardfacing alloy deposited metal. The changes in wear behavior of the deposited metal under different normal load conditions are studied. The results show that with the increase of normal load,wear loss gradually increases,but the increase gradually slows. The wear mechanism of the hardfacing alloy is the plowing effect on the austenite matrix by abrasive grains,and the VC hard phase,lamellar eutectic structure to flake.After the wear, the surface hardness increases gradually with the increase of normal load,and the subsurface of the wear mark produces significant work hardening,and the austenite matrix transforms into martensite structure,which enhances the hardness of the material and makes the deposited metal exhibit good wear resistance under high load.关键词：Fe-C-Mo-V hardfacing alloys;normal load;abrasive wear;work-hardening- 25
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发布时间：2022-03-14 - 摘要：Titanium and titanium alloy thick-wall welded tubes are the main components in industries such as seawater desalination and marine engineering. In this paper,the double gun welding method of front DC plasma filler wire welding +post pulse TIG arc is used to explore the high-quality and stable welding process of TA1 welding titanium tube with thickness of 4 mm. The non-coupling plasma welding + TIG welding forms utilize the advantages of plasma arc welding and TIG welding respectively. The results show that with the increase of plasma gas flow rate, the penetration depth of DC plasma wire-filled welding increases,which can achieve good full penetration welding of thick-walled titanium tubes;the rear TIG arc remelts the formed weld seam. With the increasing of TIG welding pulse frequency,the grain size of weld and heat affected zone is reduced,meanwhile the joint performance is also improved.The repairing effect on defects such as undercuts during the pre-plasma wire filler welding process is significantly improved by rear TIG arc. This method not only expands the process window for qualified appearance of weld,but also stabilizes the welding process. The joint strength reaches 354 MPa. Through actual production verification,low-cost high-quality welding production of thick titanium welding tube is realized.关键词：thick titanium welded tube;wire-filled of plasma arc welding;pulsed TIG welding;appearance of weld;microstructure and properties of welded joints
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发布时间：2022-03-14 - 摘要：This paper studies the surfacing metal of Nb-NiTi-B strengthened flux-cored wire,the crystalline structure and morphology were analyzed by XRD and SEM. The results show that Fe2B in the deposited metal can make the deposited metal more stable and has good peeling resistance. Fe2B has high hardness,good wear resistance and uniform distribution. It is embedded in the deposited metal as a skeleton,making the alloy have good wear resistance. TiC in the surfacing metal provides condensation nucleus for NbC to form NbC+TiC eutectic tissue,it is beneficial to promote NbC dispersion distribution while improving wear resistance. The NbC + TiC eutectic structure is dispersed in the surfacing metal,and part of the NbC + TiC eutectic structure embedded in the Fe2B structure is conducive to the fixation of Fe2B structure. By comparing the wear test of NbNi-Ti-B strengthened flux cored wire and 5C-27Cr high carbon and high chromium alloy welding wire, the wear resistance of NbNi-Ti-B strengthened flux cored wire is 2.08 compared with 5C-27Cr high carbon and high chromium alloy welding wire.关键词：hardfacing;flux cored wire;microstructure
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发布时间：2022-03-14 - 摘要：The influences of weld metals on the weldability of SUPER 304 H steel were reviewed. The results show that the hot crack tendency of GTAW austenitic weld with different composition of super 304 H steel is relatively large;the solidification crack tendency in the weld is mainly controlled by a solidification mode,while the main reason of HAZ liquefaction crack tendency is related to the precipitation phase at the grain boundary and copper enrichment and other factors. The mechanical properties of austenitic weld joints with different compositions are different. Proper weld chemical composition and optimized welding process are an important technical means to obtain satisfactory comprehensive mechanical properties of joints.The microstructures of "similar" or "dissimilar" welds formed by different compositions are all austenite + precipitates. Fusion welds are solidified in A mode,while friction welds that are not fusion welded are solidified or phase-transformed in AF mode.关键词：weld metal;weldability;SUPER 304H austenitic heat-resistant steel;hot crack;mechanical properties
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发布时间：2022-03-14 - 摘要：The processability and deposited metal properties of ENiCrCoMo-1 nickel base alloy electrode from two manufacturers were compared,and the micro morphology was analyzed. The test results show that the Ni base alloy electrode ENiCrCoMo-1 produced by the two manufacturers has good process performance,and the deposited metal composition and mechanical properties meet the requirements of national standard. In addition,due to the difference in the composition of deposited metal of Ni based alloy electrode ENi Cr Co Mo-1 from two manufacturers,the morphology and distribution of solidified dendrite and precipitated phase are different,which leads to some differences in properties.关键词：nickel base alloy;electrode;micro morphology
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发布时间：2022-03-14 - 摘要：A temper bead welding procedure without postweld heat treatment is performed at the carbon steel testing coupon to obtain as-weld deposited metal using the low alloy steel wire which is usually employed for the reactor pressure vessel. The low cycle fatigue test and high cycle fatigue test of as-weld deposited metal at room temperature are performed according to ASTM E466 and ASTM E606,and the low cycle fatigue curve and high cycle fatigue curve are constructed by means of Coffin-Mansion Equation and Tri-parametric Equation.Meanwhile,low cycle fatigue curve and high cycle fatigue curve are further revised according to the correction method recom-mended in RCC-M code which is employed for nuclear power equipment design. In addition,the revised S-N curves are compared with the design fatigue curve of low alloy steel specified in RCC-M code. The result shows that the revised SN curve（low cycle fatigue） of deposited metal basically coincides with the design curve（low cycle fatigue） specified in RCC-M code,the revised S-N curve（high cycle fatigue） of deposited metal is above the design curve（high cycle fatigue） specified in RCC-M code.关键词：reactor pressure vessel;as-weld;deposited metal;S-N curve;design fatigue curve
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发布时间：2022-03-14 - 摘要：Continuous rotary friction welding was used to aluminum and steel dissimilar metal joint. Microstructure and property was analyzed by SEM and EDS. The test results show that the aluminum-steel friction welded joint is tightly bonded and the interface is corrugated under the conditions of the rotation rate of 700 r/min,the upsetting pressure of 4.5 MPa,and the upsetting time of 2 s. The tensile strength of the joint is up to 210 MP,and the tensile fracture occurs on the aluminum side. The intermetallic compound layer with a thickness of less than 2 μm is formed by the diffusion of elements on both sides of the bonding interface of the aluminum steel dissimilar material joint. The microhardness changes step by step at the interface,and the hardness at the interface of forming intermetallic compounds is up to 230 HV.关键词：rotary friction welding;aluminum and steel dissimilar metal joint;mechanical property;microstructure
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发布时间：2022-03-14 - 摘要：The microstructure, chemical composition and oxidation of the ex-service steam tube containing T23/TP316 H dissimilar metal weld were investigated to analyze damage after service. The results show that after service for 100 000 hours at 540 ℃/17 MPa,although the TP316 H steel side is oxidized,no potential risk that may cause early failure is found;however,the T23 steel side is oxidized along the weld/heat affected zone interface and cracks along the interface is observed. The coupling interaction between interfacial oxidation damage of weld metal, the differences in thermal expansion coefficient and creep strength on both sides of the interface,and the hardness gradient near the interface is likely to induce interfacial failure and increase the early failure risk of the welded joint. In addition,some common detrimental factors such as creep and soft zone induced by carbon migration are not found at the T23 steel side,thus interfacial oxidation damage is the main damage mode of joint studied in this paper.关键词：dissimilar metal weld joint;high temperature service;creep;oxidation;hardness;chemical composition
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发布时间：2022-03-14 - 摘要：In this paper,macro and micro analysis are made on the GH4169 M60 fracture stud which is fixed bracket.Visual inspection of fracture surface shows that the feature of crack is brittle fracture,and the fracture finally occurs at the joint of the thread and nut. Penetration test finds that five continuous cracks inside the stud parallel to the thread,and SEM finds that the cracks between the threads at the fracture part show irregular sharp edges,and the fracture surface presents typical quasi-cleavage fracture characteristics. By EDS,the presence of carbide phase in the fracture is verified and the effect of carbide on brittle fracture is analyzed. The results show that the thread tends to cause stress concentration,thus enhancing the sensitivity of the stud to defects and leading to brittle fracture. Comparing the fracture surface micro-morphology of the threadless specimen,it is found that the fracture has nothing to do with the material itself,and the broken carbides are the typical characteristics of Inconel GH4169 ductile-brittle mixed fracture.关键词：GH4169 superalloy;microscopic analysis;ductile-brittle mixed fracture;broken carbide
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发布时间：2022-03-14 - 摘要：Swing check valve used in nuclear power equipment is prone to crack and wear during service,which seriously affects the safe operation of the equipment. In this paper, Fluent is used to find out the location where defects are likely to occur during the stable operation of swing check valve,and the defect location is extracted. The numerical simulation of digging repair welding process is carried out by Inte Weld. The value and distribution of residual stress and strain in the weld under different welding powers are studied.The calculation results show that the bottom of the check valve is most likely to be damaged. The welding residual stress reduces as the welding power decreases. The welding sequence is that the residual stress from both sides to the middle is greater than that from left to right. The residual stress reduces as the cooling time between passes increases. When the welding power is 2400 W,the welding sequence of each layer is from left to right,and the cooling time between each weld is 300 s,the value of the residual stress in WCB repair welding is the minimum,which is 323 MPa. The deformation can be improved when the welding sequence of each layer is adjusted to alternately from left to right and right to left.关键词：repair welding;welding residual stress;numerical simulation;check valve
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发布时间：2022-03-14 - 摘要：With the improvement of design parameters of steam turbine,the demands for high-temperature materials and related surface modification technology are becoming increasingly strong. GH901 material and its nitriding and cladding parts are also widely used in high temperature oxidation resistance and high temperature wear resistance working conditions. In this paper,plasma spray welding（PTA） is used to test stellite alloy on GH901. The effect of welding single and double stellite alloy on the microstructure and properties of the HAZ of the welded joint is studied. The results show that when using PTA method to weld Stellite,a large diffusion area of components is easy to form at bond line of the joint,and a large number of precipitates such as TiC are produced in the grain and at the grain boundary of the diffusion area. With the welding heat sequence of the two layers,the width of the diffusion area between the welding layer and the matrix increases,and the number and size of precipitates also increase.关键词：plasma spray welding;TiC;Stellite 6# alloy;GH901
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发布时间：2022-03-14 - 摘要：In this paper,the influence of 20 mm thick 6A02 aluminum alloy double-sided friction stir process on the joint microstructure and conventional mechanical properties is analyzed,and the tensile and fatigue fracture characteristics are studied. The results show that the different lengths of the stirring needles will significantly affect the mechanical properties of 6A02 aluminum alloy double-sided friction stir welded joint.When the needle length is too short,it is easy to appear cracks in the center of the transverse lateral bending specimen of the joint. When the fatigue test fails to reach the specified number of cycles under the condition of specified cyclic load and stress ratio,fracture occurs. When the needle length matches with the pressure,the tensile,bending and fatigue test performance are good,and it is found that the tensile strength of the joint increases first and then reduces as the needle length of stirring increases.When the stirring needle length is 11 mm,the tensile strength of the joint can reach 244 MPa,which is 82.7% of the tensile strength of the base material.关键词：friction stir welding;aluminum alloy;welding process;mechanical properties
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发布时间：2022-03-14 - 摘要：Butt welding of Inconel 690 heat transfer tube is conducted by gas tungsten arc welding（GTAW）. The tube welded joints are tested and analyzed by using the tensile tester,flattening tester and optical microscope. Meanwhile,the ANSYS software is used to carry out the primary stress intensity check of the welded joint when the pressure is lost in the design condition. The results show that the center of the weld is dendritic crystal,and the area near the fusion line is coarse columnar crystal. At room temperature,the average tensile strength and yield strength of the joint are 619 MPa and 292 MPa respectively. At 350 ℃,the average tensile strength and yield strength of the joint are 475 MPa and 206 MPa respectively. The fracture of tensile joint runs through the whole weld structure from the fusion zone, forming plastic fracture. The results of flattening test and reverse flattening test demonstrate that the tube joints are in good condition. Through ANSYS analysis,under the design condition,the allowable stress intensity of the heat transfer tube joint at 350 ℃ is 150 MPa,which can meet the requirements of its primary stress intensity, and the margin is large.关键词：Inconel 690 nickel base alloy;GTAW;welded joint;primary stress intensity;plastic fracture
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发布时间：2022-03-14 - 摘要：A nuclear grade 1 globe valve has internal leakage in nuclear power plant,and further inspection reveals that the cemented carbide（iron base） welded on the sealing surface of the valve has cracks,leading to internal leakage of the valve.By analyzing the causes of the cracks,the procedure and welding process control are improved,and the crack problem of the iron base surfacing are basically solved. The references are provided for the treatment of the sealing surface defects of similar nuclear grade valves in subsequent nuclear power plants.关键词：nuclear grade;valve;iron-based surfacing;crack
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发布时间：2022-03-14 - 摘要：X65 steel pipe is widely used in engineering,pipeline welding technology is developing and updating,but gas shielded welding（FCAW-G） and manual welding（SMAW）still have irreplaceable position. In this paper,through two kinds of process qualification of X65 steel pipe with large wall thickness,the reasonable test parameters are set and the difference of physical and chemical test performance between the two welding methods is analyzed. And according to the fluid medium of the pipeline,the sulfide stress corrosion cracking resistance test（SSC） is added. In view of the relatively harsh construction environment requirements of the pipeline used in offshore engineering,the corresponding welding process quality control scheme is proposed,which has a good reference value for engineering manufacturing.关键词：X65;FCAW-G;SMAW;SSC
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发布时间：2022-03-14 - 摘要：The advantages of laser welding process include high energy density, high precision,small heat affected zone and welding deformation,which is especially suitable for the welding of automobile precision parts. Laser penetration welding is used instead of arc welding to connect recliner assy and 3 mm thick connecting plate,meanwhile,there is no need to reserve process opening on the parts and the product design is more flexible. The influence of each process parameter on the welding quality is analyzed by adjusting the laser welding parameters. When the welding parameters are designed as laser power of 2 200 W,welding speed of 20 mm/s and negative defocusing amount of5 mm,the appearance of weld is good,and multiple welds are closely arranged and the penetration is over 3.9 mm.关键词：laser penetration welding;recliner assy;process optimization
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发布时间：2022-03-14 - 摘要："Welding physics" is a basic compulsory course for undergraduate welding technology and engineering specialty in our university. In order to cultivate more innovative talents to meet the needs of engineering, the teaching methods of "welding physics" course should also keep pace with the times. Therefore,in order to improve students’ learning enthusiasm as the premise,through the teaching plan of welding physics teaching material reform,ability training,project-based teaching and numerical simulation,the new teaching mode and teaching concept of "welding physics" guided by exploration are used to cultivate high-quality undergraduate graduates of welding specialty.关键词：welding physics;learning motivation;explor ation;guidance
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发布时间：2022-03-14 - 摘要：<正>2020年12月,经过多项学术指标综合评定及同行专家评议推荐,《电焊机》杂志被中国科学技术信息研究所收录为"中国科技核心期刊"（中国科技论文统计源期刊）。《电焊机》杂志多年来一直被收录为"中国科技核心期刊",在此感谢行业专家、学者、广大读者、作者长期以来的关注与支持,《电焊机》杂志将继续努力,进一步提高出版质量和办刊水平,不断增强影响力、传播力和竞争力,争创优秀精品期刊。
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发布时间：2022-03-14 - 摘要：<正>近日,由中国学术期刊（光盘版）电子杂志社有限公司、中国科学文献计量评价研究中心编制出版的《中国学术期刊影响因子年报（2020版）》正式发布,《电焊机》杂志再次入选《中国学术期刊影响因子年报》统计源期刊,在此感谢行业专家、学者、广大读者、作者长期以来的关注与支持,《电焊机》杂志将继续努力,进一步提高出版质量和办刊水平,不断增强影响力、传播力和竞争力,争创优秀精品期刊。
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发布时间：2022-03-14 - 摘要：<正>随着数字时代的到来和新媒体的出现,数字阅读已成为一种新的生活方式,期刊的数字化发行已成为转型发展重要举措。为促进学术传播和交流,扩大期刊传播范围、提高影响力,推进学术资源的公益使用和开放共享,《电焊机》杂志积极与多家数字期刊发行平台合作,以数字化方式进行互联网和移动互联网的发行与传播,竭力为读者提供优质服务。欢迎搜索阅读!
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发布时间：2022-03-14 - 摘要：<正>《电焊机》2021年第8期将以"增材制造"为主题,重点关注各种增材制造技术的最新研究进展和应用、以及增材制造装备和配套材料的研发等,期望提升制件过程的可靠性,推动增材制造在各制造领域的不同维度的研究发展。征文时间:2021年1月1日～2021年6月30日重点关注内容:增材制造技术（激光、电子束、等离子束、电弧及其复合）的国内外现状和发展趋势;
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发布时间：2022-03-14
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