最新刊期
期 11 ， 2019
- 摘要：The 3 mm thick 1Cr21Ni5Ti stainless steel lock butt joint was welded with fiber laser, the welding procedure characteristics are studied by analyzing the effect of different welding parameter on the joint quality,mechanical properties and microstructure. The results show that the main weld defects are porosity and weld pit in the weld,slow power reduction can reduce the depth of pit in weld,and negative defocus and high speed welding can effectively prevent the formation of porosity. The hardness of the weld decreases,along the weld center,the hardness of the middle area of the weld is the highest. Within a certain range of parameters,the mechanical properties of the joint are stable,and the average tensile strength of the weld reaches 816 MPa. The grain in the weld is equiaxed crystal,mainly is composed of ferrite and austenite. The amount of austenite in the middle of the weld is greater than that in the top and bottom of the weld,thus showing a higher hardness. Under the action of welding thermal cycle,the grain in the heat affected zone becomes relatively coarse,and is the weak area of weld.关键词：laser welding;lock butt joint;defects;joint microstructure and properties
- 32
- |
- 63
- |
- 2
发布时间：2022-03-15 - 摘要：The relationships between strength matching and diffusion hydrogen in weld metal were reviewed. The results show that the main sources of hydrogen in the welds of common welding methods are the moisture in welding consumables,impurities in groove and water vapor around arc. Among the influencing factors of hydrogen in weld,the GMAW method has the lowest diffusive hydrogen content,and the metallurgical reaction of hydrogen removal in arc depends on welding method,and the role of auxiliary hydrogen removal process can not be underestimated. When high strength steel is welded with low strength matching weld,the hydrogen-rich zone formed by HAZ is the weak link of the joint; when high strength matching weld is adopted,the hydrogen-rich zone of HAZ is not significant,but the hydrogen content in the weld is high,which becomes the weak link of the joint. The engineering applications of three kinds of relationships between strength matching and diffusion hydrogen in weld metal have achieved satisfactory engineering quality.In the welding of martensitic heat-resistant steel and its dissimilar steel,the innovative theory of high strength matching weld preventing HAZ from forming hydrogen-rich zone needs to be further studied.关键词：strength matching;weld metal;hydrogen-rich zone;hydrogen induced crack
- 30
- |
- 161
- |
- 1
发布时间：2022-03-15 - 摘要：The degradation of shaft components used in nuclear power equipment often occurs due to wear or corrosion,which affects the safe operation of equipment and plants. Using laser cladding technology to repair the damaged parts,the repaired parts can meet or exceed the original service performance requirements of the components,which saves a lot of maintenance and procurement costs for the power plant. In this paper,the surface defects of the motor shaft made of 410 martensitic stainless steel are repaired by laser cladding with nickel-based alloy C276 powder,and the hardness and tensile strength are tested to evaluate the mechanical properties of the cladding repair layer. The results show that the hardness and tensile strength of C276 cladding layer are about 20% and 7% higher than those of 410 stainless steel at room temperature,but the plasticity and toughness of C276 cladding layer decrease.关键词：laser cladding;cladding repair layer;mechanical property
- 34
- |
- 207
- |
- 2
发布时间：2022-03-15 - 摘要：For the Q345R+904L stainless steel composite plate with 40 mm thickness,different welding materials are used to weld the base layer,transition layer and cover layer respectively. After welding,macroscopic inspection,metallographic analysis,mechanical property test,component analysis and intergranular corrosion test of welded joints are carried out according to relevant standards. The results show that the joints obtained by the welding scheme are well formed,the tensile bending and impact properties of the joints meet the standard requirements. The joints of the composite layer are welded by E309 LMo and E385 stainless steel welding consumables respectively. Both the weld zone and the heat affected zone have acceptable intergranular corrosion resistance.关键词：composite plate;904L stainless steel;transition layer welding;intergranular corrosion test
- 51
- |
- 182
- |
- 4
发布时间：2022-03-15 - 摘要：The aluminum anodic oxide film is cleaned by using a nanosecond pulse laser. Both SEM and EDS are used for element component analysis. The results show that the newly born metal surface is composed of 99 wt.% Al element. The aluminum anodic oxide film is completely peeled under laser heating crack mechanism. The weld quality of propellant tank using laser cleaning technology reaches the highest level.关键词：laser cleaning;anodic oxide film;original metal surface;nanosecond pulse laser
- 41
- |
- 92
- |
- 1
发布时间：2022-03-15 - 摘要：Three-layer deposited metal is prepared on Q345 steel by arc welding with φ3.2 mm electrode D628. Microstructure and properties of deposited metals are analyzed by using optical microscopy,scanning electron microscopy（SEM）,microhardness tester and impact test. The results show that the microstructure of surfacing layer is mainly composed of cementite lamellae and pearlite on ledeburite matrix,the microstructure of heat affected zone is uniform and fine. As the number of surfacing layers increases,the average hardness value improves from 628.34 HV to 677.62 HV,the hardness of the third layer of surfacing layer is closed to that of second layer,and the average value is above 650 HV. The main reason is as the number of layers increases,the dilution effect of matrix on deposited metal weakens and the ratio of carbides in surfacing layer increases. The impact fracture analysis shows that the fracture mode changes from ductile fracture to quasi-cleavage fracture from the substrate to surfacing layer.关键词：electrode;surfacing welding;fracture morphology;microstructure;microhardness
- 32
- |
- 238
- |
- 2
发布时间：2022-03-15 - 摘要：Based on the analysis of the welding of flat steel,an automatic welding system is designed by using the XDM PLC as the main controller,and the three-axis motion mechanism and the R-axis rotation mechanism as actuators. According to working requirements,such as four-dimensional space degree of freedom welding requirements,system hardware configurations,the actuator design,system hardware selection,and the hardware connection form of the system are determined at first. In this paper, the composition and working principle of the automatic welding system are introduced, focusing on the coordinate transformation relationship in the visual measurement,and the calibration process is given. The compensation methods after the rotation of the welding gun at each inflection point are discussed,and the different welding parameters are used according to different seam types during the welding process. The flow chart of control program is given out for the welding gun attitudes adjustment. The welding test result shows that this designed system can track the welding seam quite well and welding quality is satisfying,the more,this system can improve the welding efficiency greatly.关键词：flat steel welding;automatic control;PLC;intelligent camera
- 26
- |
- 84
- |
- 2
发布时间：2022-03-15 - 摘要：The long tube fillet joints of boiler header are complex and numerous. the adoption of automation welding for the structure is extremely difficult because of little space and bad welding performance. Based on the characteristic of the structure,mechanized automatic welding has been chosen as its primary technical direction of automation implementation,so the mechanical welding welding work process and the corresponding mechanical welding equipment has been designed and developed. Because of the characteristic of wire feeding difficulty for the flux-cored wire,the wire feeding tube,contact nozzle and welding power source have been mainly considered and the equipment wire feeding function has been improved and verified,so the stability of the equipment have been guaranteed and it has been successfully applied in production practice.关键词：long pipe joint;mechanical welding;equipment development
- 29
- |
- 29
- |
- 2
发布时间：2022-03-15 - 摘要：The FANUC robotic workstation is introduced for welding some steel components. Due to the large difference in the shape of the components and small batch,adopting teaching tracking method will take up a lot of operator’s time,which will cause the robot to work less efficiently than expectations or decreasing accuracy generated by frequent teaching. Now the stereo vision combining with CAD model data is tried to be used to quickly scan steel components,automatically identify welds,define welding direction and fillet height offline, realize teaching-free and verify the technical feasibility of FANUC robot.关键词：robot;welding;stereo vision;weld identification
- 30
- |
- 97
- |
- 0
发布时间：2022-03-15 - 摘要：The effects of V particles on the interfacial morphology and tensile properties of Cu/Sn-58Bi-0.4V/Cu composite solder joint during isothermal aging process are studied. The results show that the microstructures of Cu/Sn-58Bi/Cu and Cu/Sn-58Bi-0.4V/Cu joints gradually coarsen,the IMC layers become thicker and the tensile strength of joints reduce with increasing aging time. However,the addition of 0.4%V particles effectively hinders the coarsening of the microstructures,inhibits the growth of IMC,and improves the tensile strength of Cu/Sn-58Bi/Cu joints. Fracture analysis shows that the fracture surfaces of Cu/Sn-58Bi/Cu are brittle. Some dimples on the fracture surfaces of Cu/Sn-58Bi-0.4V/Cu solder joints are observed,showing a certain toughness.关键词：V particles;Sn-58Bi;isothermal aging
- 28
- |
- 36
- |
- 0
发布时间：2022-03-15 - 摘要：The double-side friction stir welding is used for a 42 mm thick 6082-T6 aluminum alloy. The intergranular corrosion behavior of joints delamination specimen is studied by intergranular corrosion test. Based on the microstructure,microhardness and precipitate characteristics of the joint,the key factors affecting the intergranular corrosion behavior of the joint microdomain are analyzed. The results show that the weld nugget zones of the top and bottom layers are small equiaxed crystal structures,and under the action of double stir,the grains of the lapped weld nugget zone are finer. The microhardness distributions of the surface layer and the middle layer of the joint are W-shaped and V-shaped,respectively,and the corrosion degree of the joint does not correspond to the microhardness. Serious intergranular corrosion occurs in the base metal and HAZ2 of each layer of the joint,while no obvious intergranular corrosion is observed in other microdomains. The potential difference between the precipitates and the precipitate free zone in the base material zone and the Cu-rich phase particles on the grain boundary of the HAZ2 zone are the main reasons for the high sensitivity of the intergranular corrosion.关键词：6082-T6 aluminum alloy;FSW;microstructure;corrosion property
- 21
- |
- 157
- |
- 0
发布时间：2022-03-15 - 摘要：The TIPTIG welding method was used to weld the STKM13B carbon steel pipe with the outer diameter of 186 mm and the wall thickness of 12 mm. In this paper,the welding joints were tested by tensile strength,bent,impacted and microhardness. The results show that the TIPTIG welding method can achieve the high quality welding of STKM13B steel pipe. The impact absorption energy of the weld center and the heat-affected zone is 110 J and 49 J,respectively. The microhardness of the weld center and the heat-affected zone on both sides of the weld center is the highest,and gradually decreases with the increase of the distance from the weld center until the hardness of the substrate is reached. The joint performance is not lower than the standard requirements of the parent metal.关键词：TIPTIG welding method;pipe-pipe welding;mechanical property
- 23
- |
- 49
- |
- 1
发布时间：2022-03-15 - 摘要：In order to improve water erosion resistance of low pressure last stage blades of steam turbines,the surface of 1Cr12Ni2-W1Mo1V was hardened by high frequency quenching and the Stellite alloy was surfacing on the base metal. The microstructures and micro-hardness distributions of base metal and two kinds of strengthening layers were studied,and their water corrosion resistance were tested and analyzed. The results show that both high frequency quenching and surfacing stellite alloy can significantly improve the micro-hardness of the working layer. The average hardness of the hardened layer is 413.8 HV3N,which is 2.03 times of the base metal,while the average hardness of the surfacing layer is 404.4 HV3N,which is about 2 times of the base metal. Microstructure of strengthening layer is more uniform. The water erosion rates of the two strengthening layers are obviously lower than base metal,which indicates that both methods can effectively improve the water corrosion resistance of the material. Especially after the water corrosion test of the surfacing Stellite alloy layer,there are no obvious water erosion grooves on the surface and no large amount of metal falling off. The mass loss of the surfacing layer is only 1/9 of base metal and 1/5 of the hardened layer. The surfacing layer has better water erosion resistance.关键词：high frequency quenching;surfacing;Stellite 6 alloy;microstructure;water erosion resistance
- 27
- |
- 107
- |
- 0
发布时间：2022-03-15 - 摘要：The nuclear-grade Ni-base ENiCrFe-7 welding electrodes were developed by the optical designing of coating formula and composition of core wire. The microstructure of ENiCrFe-7 filler metals was observed by optical microscopy. The fracture morphology was observed and fracture mechanism was analyzed by scanning electron microscopy（SEM）. The precipitates of grain and grain boundaries were determined by energy dispersive spectrometer（EDS） on the SEM. The mechanical properties and intergranular corrosion resistance were tested. The results showed that the microstructure of ENiCrFe-7 filler metals was columnar austenite;the very small precipitates were observed at the grain and grain boundary. The strength,elongation,bending property and intergranular corrosion resistance of filler metals were qualified,and the impact properties performs well,which was more than 80% of the technical requirements. The fracture morphology was ductile fracture. The metal compounds contained Cr,Fe,metallic oxides contained Ti,Al and second-phase particle contained Nb were found along the migrated grain boundaries by EDS.关键词：ERNiCrFe-7 welding electrode;filler metals;microstructure;properties
- 22
- |
- 106
- |
- 0
发布时间：2022-03-15 - 摘要：Electrical additive manufacturing（EAM for short）is a kind of additive manufacturing,that melt the metal wire by arc heat and resistance heat. Due to the unique technical characters,it is the preferred additive manufacturing technology for large metal component. This paper briefly introduced the technical principle and characters of electrical additive manufacturing. Analyzed the macro-profile,micro-structure and mechanical property of the metal that produced by EAM. At the same time,briefly introduced the advantage of EAM to large metal component,the focus of attention was put forward for the development of EAM.关键词：electrical additive manufacturing;feature;application
- 24
- |
- 109
- |
- 2
发布时间：2022-03-15 - 摘要：2Cr13 martensitic stainless steel blades for nuclear power plant steam turbines are prone to water erosion during service and thin the tip of the blade. In this paper,the repair process of laser cladding Stellite 6 alloy powder was studied,and repair scheme design,process implementation and technical evaluation of the blade material were completed. The appearance size inspection,metallographic examination,ray inspection and hardness test results show that the laser cladding layer has uniform microstructure and no defects such as cracks,inclusions and non-fusion. The process of laser cladding Stellite 6 powder is very feasible. The microstructure of the cladding layer shows that the alloy grows in a dendritic shape perpendicular to the bonding surface of the cladding layer and the substrate,and the thickness of the cladding layer is up to 2 mm. The process is feasible for the repair of 2Cr13 blade of nuclear power plant steam turbine.关键词：laser cladding;stellite alloy;blades repair;additive manufacturer
- 23
- |
- 333
- |
- 4
发布时间：2022-03-15 - 摘要：Structure and properties of Q450NQR1 weather resistant steel stud welding were studied by process test,appearance inspection,bending test,torsion test and metallographic structure analysis. The results show that the welded joints with good appearance,high regularity and good mechanical properties can be obtained by short-period arc stud welding with pre-coated primer and nonprimer Q450NQR1 weathering steel. All the indexes can meet the requirements of relevant standards. The welds and heat-affected zones are pre-eutectoid ferrite,acicular ferrite and a small amount of pearlite.关键词：stud welding;welded joint;structure property
- 22
- |
- 93
- |
- 0
发布时间：2022-03-15 - 摘要：Stress corrosion cracks often occur on the inner wall of the main equipment of nuclear island in nuclear power plant during its service. At present,the technology to alleviate or repair this defect is to surfacing stainless steel,nickel-based alloy and other high toughness,corrosion-resistant alloy materials on the outer wall of the pipeline to improve the strength of the pipeline with defects,while producing compression residual stress on the inner wall of the pipeline. In this paper,an axisymmetric finite element model is established to predict the residual stress distribution after conventional welded pipe repairing and surfacing repair,and the residual stress distribution between them is compared and analyzed. On this basis,the influence of different thickness of surfacing layer on residual stress in the range of pipe wall thickness is calculated. The results show that when the width of surfacing is fixed,the thickness of surfacing layer increases from 4 to 7 layers,and the number of layers has little effect on the curve shape,but with the increase of surfacing layer,the peak value of compressive stress increases continuously.关键词：residual stress;surfacing welding;pipeline repair
- 22
- |
- 91
- |
- 6
发布时间：2022-03-15 - 摘要：Dissimilar steel welded joints are common joint types for welding structures such as boilers and pressure-bearing equipment.Through the test research on the welding joint of 20MnMo and SA-299B,the CHE557R（GB/T5117 E5515） electrode was selected for the oblique y crack test. The welding test plate,the post-weld heat treatment and the joint mechanical property test,the hardness test and the metallographic phase were carried out according to the proposed welding process. The test results show that 20MnMo and SA-299 have good welding performance;the weld microstructure is mainly acicular ferrite +pearlite structure,and the parent materials of 20MnMo and SA-299B are pearlite+ferrite,the heat effect zone is mainly bainite structure,and the carbides in the 20MnMo side heat affected zone are precipitated,showing different regional differences in joints:joint hardness from 20MnMo base metal and heat affected zone,weld seam,SA-299B thermal shadow zone and the mother material also shows non-uniformity;tensile strength,bending perf-ormance and impact toughness of welded joints meet the requirements of NB/T47014 "Welding Process Assessment for Pressure Equipment". However,the impact absorption work of the 20MnMo side heat affected zone is relatively low,which is in good agreement with the microstructure of the region. It shows that the toughness reserve of 20MnMo and SA-299B dissimilar steel welded joints is weak in the 20MnMo side heat affected zone,which has good guiding significance for engineering application of 20MnMo and SA-299B.关键词：20MnMo;SA-299B;dissimilar steel welded joints
- 32
- |
- 47
- |
- 0
发布时间：2022-03-15 - 摘要：Slender shaft parts are very sensitive to thermal deformation,especially in the case of multi-position cladding,it is difficult to control its deformation. The effects of different cladding positions,cladding sequence and constraints on the deformation of the elongated shaft were compared. Finite element method and life-and-death element technology are adopted to analyze the relation of temperature field and deforming. The experiment data were compared with ANSYS simulation data to verify the correctness of ANSYS modeling,mesh division and the real validity of temperature field,stress field and deformation simulation. In the subsequent axial repair projects,the optimal cladding path with minimum deformation and stress concentration is firstly optimized by ANSYS numerical simulation,and then the cladding work is carried out. It improves the processing quality and reduces the cladding cost to a great extent.关键词：slender axles;laser cladding;deforming;cladding sequence
- 24
- |
- 100
- |
- 1
发布时间：2022-03-15 - 摘要：This thesis mainly introduces the research and application of digital radiography（DR） and industrial computed tomography（industrial CT） technology on parts for railway freight wagons by the X-RAY source of 9 MeV electron linear accelerator. Using DR and industrial CT technology to test frame brace welding,wheel and cylinder block,not only realize high efficient and accurate testing evaluation of inner defects of parts,but also achieve the size measurement of defect and structure. In addition,the defects of shape and position are clear and intuitive to display by two-dimensional or three-dimensional images,and obtains the basic data of the process analysis and evaluation,which provides a scientific and effective detection for improving the manufacture quality and process stability,analyzing,improving and optimizing the process method.关键词：railway freight wagon;digital radiography;industrial computed tomography;detection
- 23
- |
- 174
- |
- 3
发布时间：2022-03-15 - 摘要：The welding usability,the chemical composition and mechanical properties of deposited metal, the mechanical properties of weld joints for SA-335P92 electrode E9015-B92 and E9016-B92 were studied in this paper. The results show that the whole welding usability of the electrode E9015-B92 and E9016-B92 were good and could meet welding requirements for products. The system of alloy chemical composition in deposited metal was consistent with the well-known foreign manufacturers and the main alloy elements can meet the requirement of ASME standard. The chemical composition and mechanical properties of deposited metal and weld joints could meet the requirement of standard. But alloy elements in deposited metal were almost entirely from the coating of electrode,the homogeneity and stability of main alloy elements need to be well improved. In addition,compared with E9015-B92,the impact toughness of the electrode E9016-B92 was better,and the impact toughness of the electrode E9015-B92 was strongly affected by the preservation time of PWHT.A reasonable specification for heat treatment need to be developed.关键词：electrode made in China;SA-335P92 steel electrode;experimental study
- 24
- |
- 45
- |
- 1
发布时间：2022-03-15 - 摘要：In order to solve the problem that the alloy elements such as tin and zinc gather due to the uneven heating in the process of bronze welding,which leads to the defects such as porosity,lack of fusion and cracks,thus reducing the mechanical and service properties. Based on the analysis of the characteristics of tin zinc bronze,the weldability of materials,process parameters and operation essentials,and other factors that affect the welding,the welding operation test method is adopted. In the welding process,the cleaning and drying of welding position and welding seam layer are strictly treated,the reasonable welding process parameters are formulated,the temperature and heat input between layers and sections are strictly controlled,and the small section back welding method,hammering method are adopted. After welding,heat preservation and slow cooling and other technological measures are taken to prevent the occurrence of welding cracks,welding pores,segregation and other defects,so as to promote the weld to achieve the corresponding mechanical properties and meet the actual needs of the project.关键词：statue engineering;Tin-Zinc bronze;welding process
- 25
- |
- 61
- |
- 0
发布时间：2022-03-15 - 摘要：<正>《电焊机》杂志是中国科技论文统计源期刊（中国科技核心期刊）、《中文核心期刊数据库》收录期刊"、英国《科学文摘》（INSPEC）来源期刊""俄罗斯《文摘杂志》收录期刊""美国《剑桥科学文摘》（CSA）收录期刊"
- 20
- |
- 0
- |
- 0
发布时间：2022-03-15 - 摘要：<正>书号:0111定价:26元为配合技师评聘工作的开展,满足机械行业对工人技师培训和考评的需要,加快技师培训教材建设,我们经过到上海、江苏、四川等地进行广泛的调研,并结合《通知》精神,确立了教材编写的总体思路;组织了一批由工程技术人员、教师、技师、高级技师组成的编写队伍,编写了这套《机械工业技师考评培训教材》。全套
- 23
- |
- 12
- |
- 0
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
- 21
- |
- 3
- |
- 0
发布时间：2022-03-15
- Postal code：610051
- Tel：028-83289008
- Technical support is provided by Beijing Founder electronics co., LTD 蜀ICP备07004068号-2
公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0