最新刊期
期 7 ， 2019
- 摘要：The welding residual stress of reactor pressure vessel’s（RPV）supporting ring and cylinder welded mockup with a thickness of 300 mm was investigated with the finite element method,and the stress was measured with the hole-drilling method to validate the simulated result. The investigated results shows that the through-thickness radial stress distribution within the weld zone presents a self-equilibrating distribution,and the through-thickness hoop stress within the weld zone is almost tensile stress with the peak tensile stress occurring at a certain depth beneath the surfaces and a minimum stress appears near the mid-thickness. The location where the minimum hoop and radial stress appears at the weld centerline is decided by the weld metal height of the second welding step for the welding procedure used in the present study. In addition,a large stress change occurs near the top surface of the weld metal after the first welding step due to the strong stiffness of the mockups.关键词：small modular reactor;reactor pressure vessel;supporting ring;cylinder;welding residual stress;numerical simulation;finite element method
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发布时间：2022-03-15 - 摘要：At present,the domestic mainstream nuclear power reactor type is the second-generation pressurized water reactor type. The nozzle and safety end of the key equipment are welded with different types of steel welded joints. The joint type is: the surfacing of stainless steel isolation layer（ER309L+ER308L） is conducted at the nozzle end, and then the butt welding of stainless steel welding consumables（ER308L） and stainless steel safety end is conducted. The metallurgical structure,impact properties,micro Vickers hardness distribution,micro-curve energy spectrum and fracture morphology of 16MND5/309L side bond line of 16 MND5/309L/308L/Z2CND18-12N dissimilar steel welded joints made by domestic second generation nuclear power technology are analyzed. The results show that the impact performance of the 16MND5/309L side bond line is generally low,and there are brittle fractures in some areas. The brittle fracture is generally located in the martensite zone near the bond line,mainly along the crystal fracture,and the overall distribution of the martensite zone is not uniform,and the width range has no obvious rule. The hardness value of the 16MND5/309L side bond line is the highest,and the hardness value reduces towards both sides of the 16MND5/309L interface,and a significant hardness reduction area appears near the bond line（about 0.5～1 mm） on the 16MND5 side. The carbon migration and brittle transition layer（martensite zone） at the interface of 16 MND5/309L are obvious,and a recarburization layer and a decarburization layer are formed on both sides of the bond line,resulting in a serious decline in the impact toughness of the 16MND5/309L side bond line.关键词：dissimilar steel welded joint;fusion line;martensite belt
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发布时间：2022-03-15 - 摘要：Laser nitriding is needed to improve the surface hardness and wear resistance of titanium alloys for nuclear power equipment.There are many procedure factors affecting the semiconductor laser nitriding of titanium alloys,defocus distance is one of the key factors. The effect of defocus distance on the semiconductor laser nitriding of TC4 titanium alloy is studied. Other procedure parameters remain unchanged,the laser nitriding tests of TC4 titanium alloy is carried out by using 5 mm,10 mm,15 mm and 20 mm defocus distance respectively,the surface and cross-section appearance of nitriding layer are analyzed,the hardness of nitriding layer is measured,the microstructure of nitriding ed layer is photographed,the contrast friction test of nitriding sample and TC4 matrix is conducted. The results show that semiconductor laser can nitride on the surface of TC4 titanium alloy,when the defocus distance increases,the size and hardness of nitriding layer decrease,and the comprehensive performance deteriorate. Under the experimental condition of this study,the comprehensive performance of laser nitriding layer by 5 mm defocus distance is optimal,its maximum nitriding layer thickness is 610 μm,the nitriding layer has the characteristic golden color of TiN,the maximum surface hardness of nitriding layer can reach 982 HV,which is significantly higher than of TC4 substrate（350 HV）,the wear test under the same conditions results in a mass loss of 0.2 mg for the nitriding sample and 1.78 mg for the TC4 substrate.关键词：semiconductor laser nitriding;TC4;defocus distance;hardness;wear resistance
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发布时间：2022-03-15 - 摘要：Aiming at the upper Ω seal weld of control rod drive mechanism（CRDM）in a nuclear power plant in China, primary investigation and overlaying repair technology have been carried out. Welding experiment is based on the representative test piece of 1:1 material,structure and restriction,and adopts automatic TIG welding machine. The overlaying parameters,key know-how and process flow have been achieved;by thin slice-radiographic examination,chemical analysis,metallographic examination and XRD phase analysis,the performance comparison between test piece and international typical witness piece has been done,the technical project and inspection item for overlaying piece performance examination has been established,the overlaying parameters and performance data of the upper Ω seal weld of CRDM has been obtained,so that a complete set of technology with performances equivalent to international typical witness piece’s performances has been achieved.关键词：control rod drive mechanism Ω seal weld;overlaying;technology;performance
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发布时间：2022-03-15 - 摘要：Pipeline socket weld is widely applied in the installation and joining for small caliber pipeline nuclear assistant system,it is a special form of fillet, but can not be manufactured according to the general fillet technical requirements,it had been sorted out of HAF603 lawful regulations and RCC-M specification due to special requirement. The socket welding structure is analyzed and the requirements of fillet size is determined,the welder qualification, principle of welding procedure qualification and the key points of product welding procedure are expound. The inspection requirements of welds are concluded to provide reference for the quality control and management of pipeline socket welding.关键词：nuclear power;socket welding;gap;welder qualification
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发布时间：2022-03-15 - 摘要：Composite structures of copper and stainless steel are often used in nuclear island cooling system. Copper conducts heat quickly,the heat generated by the nuclear reaction can be rapidly transferred to the stainless steel tube through copper. The cooling medium introduced into the stainless steel tube takes away the heat immediately to ensure the safety of the nuclear power system.Therefore,the welding quality of copper and stainless steel pipes plays an important role in the nuclear island cooling system. The welding procedure design of vacuum brazing of T2 pure copper and 316L austenitic stainless steel tube is conducted. For the joints with high precision gap,silver-copper eutectic solder is used,and brazing is carried out under vacuum of 8×10-3 Pa with heat preservation of 830 ℃ for 30 min. Microstructure observation and performance analysis of brazed joints are studied by shear test,metallographic microscope,micro-hardness test,thermal shock test,scanning electron microscope（SEM） and energy dispersive spectrometer（EDS）. The result shows that stainless steel and copper are successfully joined together and the brazing seam is dense. The microstructures in the middle area of the brazing seam are copper-based solid solutions and silver-copper eutectic. The shear strength of brazed joints can reach 176 MPa. The shear fracture location is in the brazing seam,and the fracture type is ductile fracture.关键词：316L austenitic stainless;pure copper;vacuum brazing;gap accuracy
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发布时间：2022-03-15 - 摘要：In this paper,the distribution of residual stresses in both transversal and longitudinal directions of the welds on the inner and outer walls of HPR1000 main pipe is studied by means of hole release method. The results show that the distribution trend of the measured values of the inner and outer walls of the specimens is tensile stress in the weld zone and heat-affected zone,and the value far away from the weld gradually decreases. Because of the large wall thickness of the pipeline,and deformation superimposed after layer by layer welding,the residual stress on the outer wall of the test piece is marginally high. The residual stress in the center of the weld seam of the inner wall reaches 100 MPa to 150 MPa. And the residual stress in the center of the outer weld of the repair weld reaches 150 MPa to 200 MPa.关键词：HRP1000;main pipe;narrow gap;residual stress
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发布时间：2022-03-15 - 摘要：Due to the complementary advantages of structure and performance,copper-stainless steel pipe composite components play an important role in the cooling system of nuclear reactor equipment. In view of the complex and difficult vacuum diffusion welding process of Cu-stainless steel in the nuclear island cooling system,the welding process is designed and the formulation of the performance study scheme,the performance evaluation and microstructure observation are carried out,which is helpful to solve the existing problems in welding. In this experiment,the method of adding Ni as the intermediate layer of coating is adopted. The vacuum diffusion welding of copper and stainless steel is carried out at a certain temperature,pressure and vacuum degree. The mechanical properties of the cop-stainless steel joint are evaluated by shear test and hardness measurement. The microstructure and diffusion bonding process of the joint are analyzed by ZEISS microscope,SEM scanning electron microscope and EDS. Through the random sampling analysis and comparison of the welded joints,it is found that the welded joints obtained by the diffusion welding test still have defects such as insufficient joint and unbalanced performance,and the welding process needs to be further optimized.关键词：vacuum diffusion welding;copper;stainless steel;Ni interlayer
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发布时间：2022-03-15 - 摘要：Aiming at the demands for welding heat input monitoring in the welding construction of nuclear power plant,a full digital IGBT inverter TIG welding machine with the welding heat input monitoring is designed and developed. This welding machine adopts DSP +ARM dual processor with TMS320F28335 digital signal processor and LPC2388FBD144 microcomputer,which realizes the digitalization of the main circuit control,human-computer interaction and external interface. By automatically recording the arc voltage,welding current and welding time during the welding process and manually inputting the length of the weld,the data of welding heat input is automatically calculated and displayed on the welding machine. The data of welding heat input can be saved in the local welding machine or USB flash disk through the USB interface,or can be uploaded to the host computer centralized control system for data transmission and monitoring through digital communication interface. The research shows that the welding machine can accurately record and monitor the welding heat input data during welding process,and meet the welding quality control requirements of nuclear power plant construction,which has broad application prospects.关键词：welding heat input;digitalization;TIG
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发布时间：2022-03-15 - 摘要：In the traditional welding production process,because of the complicated environment and the dispersed welding machines,the welding parameters are difficult to be effectively monitored. For this situation a welding parameter acquisition and wireless transmission system based on STM32 and WiFi technology has been designed. This system adopts embedded acquisition board with STM32 as the core to collect and process the welding parameters. STM32 chip communicates with WiFi module through SPI interface,collects and packages data,then sends it to the host computer via WiFi transmission network; The host computer monitoring platform is compiled by LabVIEW,monitors the welding parameters of welding machine in the welding shop and controls the transmission timing of the slave computer through the timing transmission function. The test shows that this system realizes the real-time acquisition and wireless transmission of welding parameters,has high acquisition frequency and fast transmission speed,which will help promote the transformation and upgrading of traditional welding production to information-based manufacturing.关键词：welding data acquisition;SPI interface;wireless transmission;WiFi technology
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发布时间：2022-03-15 - 摘要：The six-degree-of-freedom arc welding robot system ARCMAN-MP was used to vertical welding test,and the object of welding is the shield machine cutter head large thickness Q345B carbon steel plate. The edited vector library realized the precise swing of the welding wire in the vertical welding groove,and the vertical welding with good appearance was obtained,in the same times,a welding database was built. The mechanical properties were conducted by tensile and impact experiment,the microstructure was observed by metallographic microscope,and the fracture morphology was observed by scanning electron microscopy（SEM）. The results show that the high welding efficiency,good weld surface formation,low weld defect rate and high overall welding quality in the experiments,showing this welding method has high quality and feasibility.关键词：arc welding robot;vertical weld;cutter;welding forming
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发布时间：2022-03-15 - 摘要：At present,the working arms of tunnel construction equipment are designed with high strength,light weight,high wear resistance and long life. For welding characteristics and requirement of the boom,developed a double location for boom welding manufacturing flexible robot welding equipment,welding trajectory through 3D off-line programming software to carry on the teaching,and used in the process of welding nozzle arc sensor,probe sensor,laser distance sensor and real-time tracking of product assembly,groove and location deviation compensation to ensure the welding quality. According to the characteristics of the boom,a set of flexible welding jig which can be used for secure and reliable clamping of all kinds of boom was designed. The optimum welding parameters were obtained by welding test and process evaluation. The flexible welding robot has been successfully applied in the manufacturing and welding production of boom products for tunnel construction equipment of our company,and the product quality and production efficiency have been significantly improved.关键词：boom;welding robot;welding fixture;welding technology
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发布时间：2022-03-15 - 摘要：The hybrid manufacturing technology of additive and subtractive which is one of the important methods of integral forming complex metal components,have the advantages of high forming speed,high material utilization rate and forming complex structure in additive manufacturing and the advantages of high quality and accuracy in machining. This paper introduces the technology of additive and subtractive hybrid manufacturing as well as its current research situation both at home and abroad from two aspects of equipment integration and forming process. The study analyzes the mechanical properties,forming method and integration way of additive and subtractive equipment,mainly focuses on path planning and optimizes process parameters in hybrid manufacturing. Finally,points out the future research direction of additive and subtractive hybrid manufacturing equipment and forming process.关键词：additive manufacturing;additive and subtractive hybrid manufacturing;equipment integration;process planning;research progress
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发布时间：2022-03-15 - 摘要：In order to realize the automatic detection of weld surface defects,a weld surface quality detection method based on line laser vision sensor is studied,the extraction algorithm of weld surface defect characteristics and a classification model of weld defects are analyzed. For the defects such as pit,undercut and blowhole in the weld surface,the geometric shape and spatial distribution characteristics of different defects in laser stripe images are analyzed. Also,the feature points of weld defects are extracted by slope intercept method and segmented interval detection method. Seven characteristic parameters of weld defects are detected by feature extraction method to design a weld defect classification model based on three-layer BP neural network. These extracted seven defect characteristics are input for network training as the network characteristics. The results show that the proposed method can detect the weld surface defects such as pit, undercut and gas pore,and the overall recognition rate of the classification model can reach 91.51%.关键词：line laser vision sensing;weld defects;digital image processing;defect detection;neural network
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发布时间：2022-03-15 - 摘要：For raising the testing height as far as possible to detect micro weld seam by using magneto-optical（MO） sensor,firstly,the leakage magnetic field modeling analysis of micro weld seam is studied when the weld seam is magnetized by a DC magnetic field,secondly weld seam MO image can be obtained by putting a MO sensor above close surface of the weld seam,thirdly,through comparative studying between magnetic field intensity distribution feature of weld seam surface and the transitional zone feature of micro weld seam MO image,a micro weld seam MO imaging rule and a raising height way which can test micro weld seam as far as possible by using MO sensor are confirmed. Micro weld seam leakage magnetic field distribution model setting up by magnetic charge theory can effectively explain the weld seam MO image transitional zone information feature and it can provide a theory basis way to seek the weld seam from weld seam MO image for laser welding seam tracking and identifying and to find a way for raising the testing height by using MO sensor as far as possible.关键词：magnetic charge;laser welding;micro weld seam;leakage magnetic field;magneto-optical imaging
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发布时间：2022-03-15 - 摘要：Based on 1.8 mm thickness 304 and 430 dissimilar stainless steel sheets,the three-dimensional finite element model for heat source of friction stir welding is established by using numerical simulation software COMSOL. The temperature field distribution of friction stir butt welding of 304 and 430 dissimilar stainless is analyzed, and the effects of the rotation speed and welding speed of FSW tool on peak temperature are studied. The results show that peak temperature of the heat source center rises when the rotation speed of FSW tool increases but decreases when the welding speed increases. When rotation speed is 800 r/min and welding speed is 15 mm/min,the peak temperature increases rapidly at first and then reach the steady value of about 1 040 ℃ which appears in the rear side close to heat source. The expansion of temperature in 430 backside area is larger than taht in 304 advancing area,showing a more uniform temperature distribution. The predicted temperature filed based on finite element method shows agreement with the measured value.关键词：friction stir welding;dissimilar stainless steel;numerical simulation;temperature field distribution
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发布时间：2022-03-15 - 摘要：Aiming at the macroscopic and mesoscopic causes of hot cracking in the 7075 aluminum alloy plasma-MIG hybrid welding process. Fishbone cracking test was applied to test the welding hot cracking sensitivity. 7075-T6 aluminum alloy sheet with 4 mm thickness was welded by Plasma-MIG hybrid welding method using ER5356 aluminum alloy wire with φ1.2 mm diameter. The brittle temperature range（BTR） of the 7075-T6 aluminum alloy was measured and the hot cracking tendency was evaluated. Combing macroscopic thermoelastic-plastic method and mesoscopic crystal plastic finite element method, the numerical simulations results show that a slight strain difference will lead to the different hot cracking sensitivity, so the appropriate adjustment of the strain difference is proposed to optimize the welding process.关键词：hot crack;plasma-MIG hybrid welding;crystal plastic finite element
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发布时间：2022-03-15 - 摘要：In this paper,the welding performance,the control of welding material δ ferrite and the selection of post-weld heat treatment parameters of SA-312TP316H pipe for utility boiler with heavy caliber and large thickness are analyzed,as well as the performance of the welded joint was tested. The test results show that the matched welding material with 5% ～10% δ ferrite has good weldability,controllable weld quality,and the mechanical properties of the welded joints can meet the requirements of the standards and engineering applications.关键词：thick-wall;TP316H pipe;weld;test
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发布时间：2022-03-15 - 摘要：The chemical composition and mechanical properties of X65 and SA234 WP22 CL3 seamless steel pipes are briefly introduced,and their weldability is analyzed respectively,then the selection of welding materials and the formulation of welding parameters are determined. According to the welding technical requirements of X65 main pipe and SA234 WP22 CL3 three-way pipe fittings for compressors,the welding procedure qualification of X65 and SA234 WP22 CL3 seamless steel pipe with φ168.30×14.27 mm is carried out. The results show that all index of welded joints meet the design requirements by using tungsten argon arc welding wire ER50-G for backing welding and manual arc welding electrode E5015-G for filling and cosmetic wleding,the microstructure of welded joints is mainly ferrite and a small amount of pearlite. Site welding has also achieved good results,indicating that the welding parameters and heat treatment procedure are reasonable and feasible.关键词：X65;SA 234 WP22 CL3;weldability analysis;welding procedure qualification
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发布时间：2022-03-15 - 摘要：7N01 aluminum alloy can be widely used in high-speed train bearing beam and other structural parts,with high strength,good extrusion and corrosion resistance. Some studies have shown that the combination of appropriate high frequency pulse current on the basis of welding current can significantly affect the solidification structure of liquid metal in the weld pool of aluminum alloy,which is beneficial to improve and enhance the welding quality of aluminum alloy. At present,most of the pulses used in the experiment are low-frequency pulses,in order to enrich and expand research in related fields,the TIG welding process based on DC/pulse TIG welding combined with high-frequency pulse（frequency f>40 kHz） is adopted in this experiment,welding on 7N01 aluminum alloy plate,collection and analysis of signals and temperature signals. The effects of DC/pulse combined with different high-frequency pulses on electric signals and temperature field signals are compared and analyzed,so as to provide theoretical basis for improving high-frequency pulse welding process and welding quality.关键词：high strength aluminum alloy;high-frequency pulse current;electrical signal;temperature field
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发布时间：2022-03-15 - 摘要：Macroscopic examination,micro-morphology analysis,metallographic examination,Brinell hardness and micro-Vickers hardness test were carried out for the fillet weld of the steam turbine high pressure inner cylinder drain pipe. The results showed that there were continuous incomplete penetration defects at the root of the fillet weld between the drain tube and the cylinder block,and the Brinell hardness and local microhardness of weld,heat affected zone were high,especially near the fracture surface of weld generally higher,the microhardness at the abrupt change of weld shape in the impermeable position was the highest,where the main crack originated. The reason for the fracture of the drain pipe was the improper welding control,continuous incomplete penetration defects were occurred at the root of fillet weld,which leaded to stress concentration. Under the long-term high temperature environment and high circumferential stress,the crack initiated at the abrupt change of the weld shape in the incomplete penetration position and extended to the outer wall and circumferential direction,resulting in the fracture failure of the joint. Attaching importance to and controlling welding quality and taking effective measures to eliminate welding residual stress was the key to avoid such problems. The analysis results of this paper are of great significance to the safe operation of power station steam turbine.关键词：lack of penetration;stress;crack;fracture
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发布时间：2022-03-15 - 摘要：In this paper,through analysis the composition structure of curved beam in aluminum alloy high-speed EMU,a set of threesided turntable integrated welding tool equipment for end-wall curved beam was developed,to form a high-efficiency welding process for end-wall curved beam with rapid positioning and assembly features. Many process steps,the pre-weld positioning assemble,formal welding,setting of positioner,compactor and reverse deformation,are integrated together by our process. The end-wall bending beam does not need to be adjusted after welding,and its verticality,profile degree and flatness meet the design requirements. It reduces the operation space and the labor intensity in production,and effectively solved the production mode of small-size thin-plate work pieces,mass production and standardized operation for end-wall curved beams and arched beams,which greatly improves production efficiency and product quality.关键词：end-wall curved beam;three-plane turntable;integrated group-welding tool equipment
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发布时间：2022-03-15 - 摘要：Off-shore platform is a kind of steel structure,which is widely utilized for exploration of off-shore oil and natural gas.Structure discipline is the main composition of platform,which is mainly connected by welding,nevertheless,residual stress which results from the welding process may lead to deformation of structure,furthermore,the deformation may have a bad effect on the overall property of platform. This text details the dimensional control measures of structure welding.关键词：welding;deformation;dimension control
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发布时间：2022-03-15 - 摘要：<正>书号:0023售价:58.00元本书介绍了逆变式弧焊机相关的基本电路、功率器件、高频变压器设计及铁磁性材料、高频电容器、PWM集成控制电路、电流传感器、新型绝缘材料等基础知识,同时对逆变式弧焊机发展过程中存在的可靠性、节能、电磁兼容等一系列热点问题进行了探讨和论述,并通过对目前具有代表行的各种逆变式弧焊机的具体描述,反映其市场动态和现状,跟踪逆变式弧焊机的最新发展
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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。3《.电焊机》杂志已被多家国内外权威收录机构、数据库、专业网站、及本刊公众微信"焊割在线"列为来源刊,
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