最新刊期
期 8 ， 2020
- 摘要：In order to detect dynamic forming process of diode laser cladding,an acquisition system based on high-speed camera was established,and the diode laser cladding experiments with different welding parameters were carried out.The typical characteristic behaviors of this process were extracted by analyzing the collected photos,and the influence of welding parameters on different characteristic behaviors was analyzed and explained. The results show that a complete cladding process includes four typical characteristic behaviors:（1）Particle agglomeration occurs when powder bonding;（2）Small diameter liquid metal balls form;（3） Liquid metal balls with smaller diameters come together to form larger balls;（4）Larger balls are wetted and spread out to form cladding metal. The increase of laser power significantly reduces the duration of characteristic behavior（3）. Improved defocusing amount impr-oves the duration of four characteristic behaviors. When the particle size of the powder is larger than 300 mesh,the duration of all characteristic behaviors significantly reduces.
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发布时间：2022-03-15 - 摘要：The tendency of reheat cracks of heat-resistant steel joints involved in the slit type cracking test was discussed. The results show that the cracks which start at the stress concentration at the root of the joint,propagate along the grain boundary of HAZ overheated zone and stop at the weld or HAZ fine grain zone are found in the slit type cracking specimen of BHW35 steel after stress relief heat treatment,and their properties are reheat cracks. The microstructures of HAZ coarse-grained zone are the necessary conditions for the formation of reheat cracks,while the restraint stress,hydrogen and high temperature behavior in the joint are the sufficient conditions for the formation of reheat cracks. In order to reduce the stress level in the joint,minimize the hydrogen content in the joint,control the formation conditions of reheat cracks,the comprehensive processes such as low stress and low hydrogenation and special welding materials are commonly used in production,and more satisfactory results have been obtained.关键词：reheat crack;heat-resistant steel;slit type cracking test;restraint stress;diffused hydrogen
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发布时间：2022-03-15 - 摘要：In this paper,the thermo-elastic-plastic finite element method is used to calculate the residual stress of butt welding of AH36 marine high-strength steel. The longitudinal and transverse residual stress distributions in the directions of two paths near the weld zone are obtained. The effects of different welding sequences on the welding residual stress and its release during the welding process are analyzed. The calculation results show that the welding residual stresses on the two paths are greatly affected by the welding sequence. The initial transverse and longitudinal welding residual stresses of working condition one and working condition four are small.After applying 50 times of tensile cycle load, the release rate of longitudinal and transverse residual stresses of working condition one is the largest and the stress value is the smallest.关键词：welding sequence;welding residual stress;numerical simulation;release rate
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发布时间：2022-03-15 - 摘要：In order to verify the feasibility of keyhole gas tungsten arc welding（KTIG） technology in the field of offshore engineering equipment manufacturing,A36 and E36 steel plates for offshore engineering are root welded by KTIG,and filled and covered by submerged arc welding. The abilities of doublesided forming and deep penetration,and mechanical proper-ties of the welded joint of KTIG welding are studied and tested. It is verified that KTIG welding technology has good abilities of single-sided welding double-sided forming and deep penetration,and good tolerance of assembly clearance.The results show that the KTIG welding meets the general steel structure welding standards and offshore engineering equipment manufacturing industry standards. And it has a broad application prospect in the field of offshore enginee-ring equipment manufacturing.关键词：offshore engineering;KTIG;one side welding double side forming;deep penetration welding
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发布时间：2022-03-15 - 摘要：The surfacing layers with different boron（B）element content are obtained by adding different amounts of boron carbide（B4 C） powder into the self-shield surfacing with flux-cored wire powder. Metallographic observation shows that the matrix of surfacing layer is a composite structure consisting of austenite and martensite,a eutectic component（Mo,Cr,Fe,Nb）2 B interruptedly distributes along the grain boundary. The hardness and wear resistance of surfacing layer can be improved by solid solution strengthening effect,but metastable phase δ-ferrite causes the crack in surfacing layer. After aging treatment at 500 ℃,the metastable δ-ferrite will transform into the σ-ferrite,which can effectively prevent cracks and improve the hardness and wear resistance of surfacing layer. The optimum addition of boron carbide（B4 C） in powder is 1.5%,the maximum hardness is 47 HRC,and the wear resistance is 3 times higher than that of the surfacing layer obtained by flux-cored wire without element B. Using this wire as a surfacing material to repair the stop valve can prolong its service life and has good corrosion resistance and high economic value.
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发布时间：2022-03-15 - 摘要：Nitrogen and niobium were added into the coating of Fe-Cr13-C hardfacing electrode for alloying, and then the hardfacing test was performed. The microstructure of hardfacing layer metal was observed by optical microscope and scanning electron microscope. Moreover,the wear resistance property of hardfacing layer metal was tested by sliding friction wear tester, and the effect of niobium and nitrogen on the wear resistance property of Fe-Cr13-C hardfacing alloy metal was studied. The results show that the addition of niobium and nitrogen in the hardfacing layer alloy can refine martensite and make the precipitation phase distribu-tion more uniform. It has obvious fine grain strengthening effect and precipitation strengthening effect. The hardness of the hardfacing alloy increased by about 25%;the maximum depth of the wear scar reduced by about 72%,and the average cross-sectional area of wear scar reduced by about 81%. The wear resistance of the hardfacing alloy improves significantly.关键词：alloying;hardfacing;microstructure;wear resistance
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发布时间：2022-03-15 - 摘要：This paper introduces the composition and basic operation principle of the Dual-Robot Simulation Platform System for Truck Axle Welding through realistic scene simulation. The Dual-robot welding experiment for Truck Axle is carried out based on Dual-Robot welding system and automatically running program. Results show that the Dual-Robot Simulation Platform System can give full support for the advanced functions and take a huge role on Flexible Processing System. The article also introduces the platform in the practical teaching of auto-arc welding robot system.关键词：dual-robot system;welding;truck axle;practical teaching
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发布时间：2022-03-15 - 摘要：In view of the existing grinding and cutting equipment to limit the size of welded pipe,spend a lot of labor time and other problems,a set of welding tumor cleaning equi-pment with image recognition control system is designed,and the current fixed clamping device is improved to achieve excellent results in the work of different sizes of welded pipe nodule cleaning. Image recognition control system of the equipment can collect the internal image of the welded pipe in real time,and adjust the position and angle of the grinding machine through the image processing program at the PC end to realize the automatic operation of the whole equipment. Com-pared with the traditional welding machine,it has the advantages of simple and convenient operation,saving labor and so on. In addition,changing the traditional fixed clamping structure of the welded pipe to the chuck clamping rotating type can improve the cleaning accuracy and efficiency and adapt to welding tumor of different shapes and heights.关键词：solder joint cleaning;image recognition;design analysis;chuck clamping rotating structure
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发布时间：2022-03-15 - 摘要：In the welding process,electrical signals are closely related to the welding quality. Ultra-narrow gap welding is a new welding method with high efficient and low heat input.However,its arc control and metal transfer process are complex,the traditional signal feature extraction and analysis method often can not fully express and make full use of the time series information. Combining with the characteristics of ultra-narrow gap welding process,the complete time series of electrical signals are used to construct the convolutional neural network,while deeply excavating the timing information of the same attribute signal, the time correlation information between welding current and arc voltage signals acquired synchronously is fully consi-dered to predict welding quality. The test result shows that the proposed deep network model based on the complete time series signal can predict the welding quality accurately,and the accuracy rate reaches 95%,in the case of adopting RTX2080 GPU as the computing accelerator,the time required for the model prediction is only 0.178 ms,which lays a foundation for the real-time prediction of ultra-narrow gap welding quality.关键词：ultra-narrow gap;time series data;convolution network;quality prediction
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发布时间：2022-03-15 - 摘要：The control rod drive mechanism（CRDM） weld is used for mechanism sealing in nuclear power plant. CRDM replacement occurs during the construction and operation of nuclear power plant. At this time,the lower weld of CRDM needs to be cut, and after repairing cutting groove,the CRDM will be reinstalled,or a new CRDM parts will be re welded and inspected.Aiming at the difficulties of CRDM cutting and replacement in nuclear power plant,through the cutting and welding test of CRDM standard specimens,the influence of welding deformation on CRDM cutting,groove repair and rewelding is analyzed. And the suggestions are put forward about the clearance of reinst-allation and the selection of CRDM components after CRDM cutting,which provides reference for CRDM cutting and repla-cement in nuclear power plant.关键词：nuclear power plant;control rod drive mechanism（CRDM）;welding deformation;cutting
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发布时间：2022-03-15 - 摘要：Due to the welding characteristics of titanium alloy itself and the complexity of welding structure in high-speed rail bogie,how to ensure the welding quality and size requirements in the welding process has become the biggest difficulty in the production and manufacture of titanium alloy high-speed rail bogies. Especially the bogie frame,as the important working procedure of the welding of the bogie,the guarantee of its quality and accuracy is the key to follow-up production of the bogie. By compiling reasonable welding process rules,we have effective regulations on the preparation before welding, the sequence of pairing,the welding sequence,the requirements of welding parameters,the preparation of tooling and the requirements of heat treatment,etc,so as to improve the welding quality and size requirements of the bogie frame. Through the actual welding of the bogie side beam on the spot,the weld quality after welding meets the requirements,and the side beam size meets the requirements of the bogie pairing.
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发布时间：2022-03-15 - 摘要：A new method of welding the ultra-narrow gap with flux strips constraining arc can heat both sides of the root of groove at the same time,and realize the single channel multi-layer welding of 4.5 mm straight groove. We carried out a series of welding tests of ultra-narrow gap welding for horizontal butt joint and realize 60 mm thick butt joint by changing the process parameters. The results show that the welding voltage affects the melting depth of the upper side of the groove,the welding current and welding speed determine the melting amount of the welding wire,and the reasonable cooperation between them can make the minimum downward flow of molten pool. The ultra-narrow gap welding pool is small, the solid-liquid contact surface is relatively large,its surface tension is easy to balance the gravity of the pool,and it has certain advantages to prevent the defects of the pool in the transverse welding.关键词：ultra-narrow gap;horizontal welding;welding parameters;forming quality
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发布时间：2022-03-15 - 摘要：In this paper, B1800 HS/DP1180 resistance spot welding joint is taken as the research object. The macroscopic morphology of the weld was observed by ultra-depth micro-scopy. The microstructure of the weld was studied via optical microscope（OM） and the hardness distribution of the joint was measured by the Vickers microhardness tester. The results show that the microstructure of B1800 HS is fine lath mart-ensite. The nugget of the spot welded joint is good and asymmetric and the microstructure is thick lath martensite. The nugget diameter is 6 500.32 μm. The nugget depth is 1 868.17μm, the width of the heat affected zone is 692.63 μm and the electrode indentation depth is 216.04 μm,which conforms to the industrial standards of Japan and Germany. The weakest part of the joint is the subcritical heat affected zone,the microstructure is tempered martensite and the hardness is the lowest,271 HV0.3,where cracks are usually produced.关键词：hot stamping;B1800HS;DP1180;resistance spot welding;heat affect zone
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发布时间：2022-03-15 - 摘要：A kind of welding procedure used for the closed self-melting welding of pipelines in nuclear power plants is introduced. Through the early market research,equ-ipment selection and procedure development,a set of mature closed self-melting welding method is developed for field welding of fine thin-walled pipe,which replaces the traditional manual welding method,saves cost effectively,ensures welding quality,improves construction efficiency,and provides refere-nce for the application of closed self-melting welding for fine pipelines in nuclear power plant.关键词：nuclear power plant;pipeline;closed self melting welding;equipment selection;welding procedure
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发布时间：2022-03-15 - 摘要：This paper takes the field assembly and welding of CA20 structural module as an example,introduces the difficulties of field assembly and welding of CA20 large stru-ctural module,and the welding process and process of field assembly and welding of sub-modules and composite parts.Analyzes the reason of welding deformation of structural modules in site assembly,summarizes the methods of welding deformation control of structural modules in common use,and puts forward the measures of welding deformation control of control structure modules in site assembly according to the characteristics of large structural modules,which provides reference for welding deformation control of large structural modules in site assembly of nuclear power plant.关键词：nuclear power plant;structure module;welding;deformation control;factory acceptance
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发布时间：2022-03-15 - 摘要：6063-T5 aluminum alloy finned radiator products with a thickness of 17.6 mm were successfully fabricated by friction stir welding. Optical microscope and scanning electron microscope were used to analysis the microstructures and fracture of the joint, and the tensile properties were tested. The results show that the lamellar tearing defects in the surface of the weld is caused by the oxide aggregation distribution. The chemical composition of the oxide layer is mainly Al2 O3 and Mg O. In terms of mechanical properties,the tensile strength of the joint is 170 MPa after 180 ℃,10 h aging treatment,which is 106% of the base metal,the tensile fracture location occurred at the heat affected zone of advanced side with a ductile fracture mode.关键词：friction stir welding;layered tear;oxide;tensile strength;thick aluminum alloy plate
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发布时间：2022-03-15 - 摘要：The welding technology of 6 GR position in offshore platform TKY node is introduced,such as the assessment rules,the preparation and assembly of welding specimen,and systematically summarized the typical welding process parameters,the main control points of back welding,filling welding and cover welding,which according to the characte-ristics of offshore platform construction,combining with many engineering examples and successful experience. The conne-ction of the TKY node is the key connection position between the structural components,which can form a closed and complete structure between the components. The welding work at this position has always been the focus and difficulty of welding quality control in the offshore oil industry. The introduction of 6 GR technology brings new ideas to the quality control of offshore platforms and structures.关键词：offshore platform;TKY node;6GR position;welding
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发布时间：2022-03-15 - 摘要：For the icing phenomenon in the bogie area of high-speed train in winter,the anti-icing coating is prepared to slow down the phenomenon. In this paper,the micro-nano structure coating is prepared by supersonic flame spraying WC-Co powder,and different low surface energy materials are modified on its surface to study the influence of low surface energy modification on the static contact angle of coating. The results show that adopting hydrophobic fumed nano silica treated with different concentrations and procedure parameters,the contact angle can be increased. The optimum low surface energy modification procedure is as following:the concentration of Si O2 acetone solution is 20 mg/m L,spraying distance is250 ～300 mm,spraying angle is 75° ～80°,spray gun moving speed is 60 mm/s,spraying passes are 5 times,and compressed air pressure is 0.65 MPa. And the contact angle of 154.3° ±3.0° and rolling angle of 4.1° ±0.1° can be obtained by this procedure.关键词：superhydrophobic;low surface energy;coating;static contact angle
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发布时间：2022-03-15 - 摘要：By adjusting the ratio of EP and EN,AC MIG welding can control the penetration and wire melting speed,so it is suitable for welding thin plates. But AC MIG welding is difficult to reignite the arc when EP and EN polarity change.This paper studies a circuit to maintain AC arc stability,when EP and EN polarity change,a high voltage is generated to help reignite the arc. It can effectively solve the burn-through problem during high-speed welding of thin plates.关键词：AC MIG;arc stability;arc reignition
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发布时间：2022-03-15 - 摘要：Shell Process gasifier with waste boiler has the advantages of wide adaptability of energy coal type,high carbon conversion rate,large single-series production capacity,long operation cycle,etc. But the manufacturing technology is monopolized by foreign countries,and there is no manufacturing experience in China. This paper points out the process method of automatic welding of non-linear thick wall large diameter cylinder butt joint in Shell gasifier and chemical container,which has been successfully used in production practice. And from the product structure characteristics,product focus,assembly size requirements,automatic welding characteristics,how to realize automatic welding of non-linear thick-walled large-diameter cylindrical elliptical section is introduced. The process has been successfully applied in engineering practice with good results.关键词：non-linear;elliptical section;assembly requirements;product focus
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发布时间：2022-03-15 - 摘要：Cu was used as the intermediate layer for laser welding to realize the high quality joining of TC4 tita-nium alloy and 316 L stainless steel dissimilar metal. The results show that the Cu interlayer can effectively inhibit the brittle Ti-Fe intermetallic compound produced at the inter-face. And the tensile strength of welded joint significantly improves as welding speed increases. The interface of TC4 titanium alloy and weld is mainly composed of continuous Ti-Fe compound layer and intermittent Ti-Fe and Ti-Cu compound layers with thickness of 60 μm. The brittleness of welded joint is reduced,cracks are inhibited and joint stress is relieved,and good titanium/steel dissimilar metal laser welded joint is obtained.关键词：titanium alloy;stainless steel;laser welding;numerical simulation;microstructure
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发布时间：2022-03-15 - 摘要：In order to solve the housing fatigue fracture problem in a middle-sized drive axle under vertical bending loading condition,this paper analyzes the characteristics and causes of the Y-shaped joint fatigue fracture of the housing assembly bearing the vertical bending alternating load. Three methods are proposed to improve the fatigue life of housing welding:（1）change the design scheme,move the triangular plate weld inward by 12.5 mm;（2） groove the weld joint;（3）adopt the new constant penetration MAG welding process to weld the Y-shaped joint. The above three methods ensure the weld penetration to avoid the generation of Y-shaped joint fatigue crack of housing assembly and improve its fatigue life.关键词：drive rear axle housing assembly;numerical simulation;fatigue life;deep penetration welding
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发布时间：2022-03-15 - 摘要：The quality,safety and health risks of 9% Ni steel vertical weld by shielded manual arc welding for large LNG tank are mainly discussed. Through analysis and field construction experience,it is found that the causes of these hidden dangers are poor replicability of welding procedure,manual operation of welder,carbon arc gouging back chipping,extensive grinding,inadequate supervision,difficulty of high altitude operation,etc. It is suggested that using an efficient automatic AC GTAW welding procedure to replace the traditional shield manual arc welding. This suggested welding procedure has the characteristics of high quality,strong adaptab-ility,cleanliness and high cost performance.关键词：9% Ni steel;SMAW;quality risk;carbon arc gouging;carburized layer
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发布时间：2022-03-15 - 摘要：In view of the problems of many welds, high welding difficulty and easy to produce defects in the welding of hydraulic cylinder parts,the test is carried out by MAG welding with common material for hydraulic cylinder. In order to ensure the welding quality and prevent the welding cracks and other defects,the welding parameters are made for different materials,and appropriate technological measures are provided.When evaluating the postwelding test piece,it shows that the weld is well formed,the welding deformation is small,the surface and internal defects are few,and the ultrasonic flaw detection and mechanical property detection are qualified. The results show that the welding quality is good,the welding procedure is reasonable and feasible,and it can completely meet the working requirements of the hydraulic cylinder of construction machinery.关键词：hydraulic cylinder;MAG;welding performance
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发布时间：2022-03-15 - 摘要：Potentiodynamic polarization curves and electrochemical impedance spectroscope were used to study corrision behavior by the six groups welding process parameters of two joint forms and three groups of welding current in 3.5% Na Cl solution. The results show that the erosion resistance of the butt welding under the each welding process parameters is better than the fillet welding,the numbered Ⅳ parameter is optimal.Choosing good welding process parameters can improve the corrosion resistance of welding joint.关键词：titanium tube;welding process parameters;electrochemical corrosion test
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发布时间：2022-03-15 - 摘要：In this paper,the CHE507 RCW electrode deposited metal with different Cu content was taken as the research object. Firstly,the microstructure of the deposited metal was observed by metallographic microscope,and then the weight loss corrosion experiment was carried out by simulating the corrosive environment of the cargo tank of the oil tanker. The corrosion behavior of the sample in the high acid and high Cl-concentration environment was studied. The effects of Cu content on the corrosion resistance of the weld samples were studied by means of electrochemical analysis and scanning vibration reference electrode technique（SVET）. The results show that the microstructure of the deposited metal consists of ferrite + a small amount of pearlite + a small amount of second phase particles;the sample undergoes hydrogen evolution corrosion at the initial stage of the reaction,and pitting occurs with the prolongation of corrosion time;Inside,with the increase of Cu content,the microstructure of the deposited metal tends to be uniform and fine,the precipitates at the grain boundary become less,the self-corrosion potential gradually shifts,the self-corrosion current gradually decreases,the corrosion resistance increases,the surface corrosion products become dense and the pitting corrosion resistance is enhanced.关键词：cargo oil tank;weld;corrosion resistance;Cu content;SVET
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发布时间：2022-03-15 - 摘要：<正>最近发现网络上有大量假冒的《电焊机》杂志的官方网站,并以编辑部名义进行征稿及收取征稿、审稿费用。《电焊机》杂志在此声明:%%一、《电焊机》杂志投稿途径如下:%%投稿官方网站:《电焊机》杂志官网www.71dhj.com（在线投稿）编辑部邮箱:bj@toweld.com编辑部电话:028-83289008除此之外,《电焊机》再无其他投稿方式。二、《电焊机》杂志从未有偿审稿,也从未以任何方式授权其他单位（机构）及个人使用编辑部名义收取稿件。
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发布时间：2022-03-15
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