最新刊期
期 8 ， 2022
- 摘要：Laser manufacturing application is the main direction of laser industry application. Power beam processing represented by laser processing is an indispensable technology in the aeronautical industry. In this paper , the structural requirements and material development of various generations of military aircraft is summarized, the challenges and development trend of military aircraft structural parts manufacturing is analyzed and the application status of laser processing technology in titanium alloy aviation structural parts manufacturing is introduced. Laser welding technology is mainly used for the welding of skin and truss and the welding of abdominal fins and wing flaps. Laser additive manufacturing is mainly used for the rapid manufacturing of complex titanium alloy body structural parts, and the application in the near future is prospected. Compared with traditional titanium alloy processing technology, laser welding technology and laser melting deposition technology can realize large-scale and integrated manufacturing of structural parts. Laser selective melting technology can realize the manufacture of complex topological structural parts. These manufacturing technologies can effectively reduce the weight of the body, increase the fatigue life of the body, improve the utilization rate of materials, and reduce manufacturing costs; finally, combined with the current international background and the requirements of the new era, the development trend of laser processing equipment in the manufacturing of titanium alloy aviation structural parts is prospected. The multifunctional complete system, intelligent processing process, efficient supporting equipment and independent core components will enhance the core competitiveness of China's high-end laser processing equipment and help the manufacturing of titanium alloy aviation structural parts.关键词：aeronautic structure;laser welding technology;laser additive manufacturing;titanium alloy
- 124
- |
- 28
- |
- 0
发布时间：2022-09-15 - 摘要：In order to prevent and deal with nuclear power plant accidents, the concept of ATF (Accident Tolerant Fuel) material emerged. It is of great significance to select the proper material and manufacturing method of the cladding tube which protects the nuclear fuel core. SiC ceramics has become a candidate material for the next generation of nuclear fuel cladding tubes due to its excellent mechanical properties, corrosion resistance and radiation resistance. Due to the intrinsic property of SiC ceramics, it is difficult to form SiC base cladding. To ensure the gas tightness of the end cap, the joining technology of SiC is the focus of researchers at home and abroad. The basic properties, application prospects in nuclear field and preparation method of SiC ceramics are introduced. The research status of diffusion bonding and brazing bonding of SiC ceramics is emphatically reviewed. The advantages and disadvantages of diffusion bonding materials including Ti, Mo and Ni/Ti and brazing filler materials including Ag-Cu base, Pd base, Co base, Ni base, Ti base and Al base fillers are analyzed. The property differences of joining materials under high temperature, irradiation and corrosion environment are discussed. Finally, the application of SiC ceramics joining technology in cladding is evaluated and prospected.关键词：ATF;cladding material;SiC ceramic;brazing;solid diffusion bonding
- 101
- |
- 17
- |
- 0
发布时间：2022-09-15 - 摘要：Diamond tools are widely used in manufacturing industry because of their excellent properties of high hardness and good wear resistance. In this paper, the excellent properties, application fields, classification and manufacture methods of diamond tools are introduced. The advantages and disadvantages of different preparation methods were analyzed and compared. The brazing and diffusion bonding method of diamond tools are introduced emphatically. The overseas and domestic research status of brazed and diffusion bonded diamond tools are summarized in terms of joining technologies, equipment and filler materials. The mechanism of improving joined diamond tool’s performance is summarized. The existing problems of welded diamond tools are analyzed, and the development direction of brazed and diffusion bonded diamond tools in the future is prospected.关键词：diamond tools;surface metallization;brazing filler metal;active brazing filler metal;diffusion bonding
- 75
- |
- 13
- |
- 0
发布时间：2022-09-15 - 摘要：The focusing current and scanning mode jointly control the energy distribution of the electron beam on the workpiece surface, which has an important impact on weld formation in electron beam welding. Based on the surfacing welding test of 5A06 aluminum alloy plate matched with 5B06 welding wire, the effects of focusing current change, scanning waveform, frequency and amplitude on weld formation in electron beam wire filling welding were studied by single variable method. The results show that in order to ensure that the beam energy density is enough to fully melt the welding wire and then obtain good weld formation, the adjustable range of focusing current is relatively narrow, and the deviation from the surface focusing current needs to be controlled within -5~+10 mA. If the porosity defect of the weld is reduced by scanning mode, circular scanning is preferred, and the scanning frequency and amplitude should be controlled within the range of 500~1 000 Hz and 0.8~1.2 mm, respectively.关键词：aluminum alloy;electron beam welding;filler wire;focusing current;scan mode
- 49
- |
- 9
- |
- 0
发布时间：2022-09-15 - 摘要：Electrode E318-15 was overlaid on the end of a pipe(16Mn) by manual electrode arc welding under the same current and voltage, half of the circle is welded along the circumferential direction, and the remaining half circle is welded along the radial direction(horizontal welding). After welding, samples were taken from the ring welding area and the horizontal welding area, to obtain the differences between chemical composition, microstruction, and microhardness. The results show that the samples from horizontal welding area have a higher content of Cr, Ni, Mo, Nb, V, Si elements, as the maximum ratios are 144%, 136% ,116%, 136%, 150%, 11%, but a lower content of C element，as the maximum ratio is 52%. On the side of deposit layer, microstruction are mainly the same, but it is obviously different on both sides of the fusion line. On the base material side of the girth welded specimens have a narrower grain coarsening zone, and meanwhile some Widmanstatten structure is discovered among this zone. Because of the different welding methods, the difference in the amount of pass and the welding speed will lead to the change of the dilution ratio and heat input of the base metal, which will lead to the difference in the microstructure and properties near the surfacing interface of the joint.关键词：surfacing stainless steel E318-15;welding methods;dilution ratio;martensite-like;Widmanstatten structure
- 75
- |
- 19
- |
- 0
发布时间：2022-09-15 - 摘要：Aluminum alloys tend to produce pores during welding, which critically affects the mechanical properties of the weld. The laser oscillating welding can significantly reduce the porosity of aluminum alloy welding. However, it is very difficult to figure out and optimize the welding parameters since they are in a complex relationship. To study and figure out the influence of different parameters on porosity, 18 sets of orthogonal experiments are designed followed by the analysis of variance. In addition, the welding parameters are optimized by the analysis of variance. The multi-objective optimization of weld performance and welding efficiency are carried out by using genetic algorithm combined with BP neural network. The tensile strength of the weld optimized by genetic algorithm is increased by 3.02% and the welding efficiency is increased by 18.3% compared with the orthogonal optimization. Therefore, the combined model of BP neural network and genetic algorithm can improve welding efficiency while ensuring welding performance.关键词：laser oscillating welding;orthogonal test;backward propagation neural network;genetic algorithm;parameter optimization
- 62
- |
- 8
- |
- 0
发布时间：2022-09-15 - 摘要：In this paper, a three-dimensional geometric model of the welded excavator bucket was established by using UG software. By importing MSC.Marc and ANSYS Workbench, finite element simulation and analysis were carried out respectively for the welding process of the key welding seams and the force of bucket tooth under different loading conditions. The stress and deformation of welded bucket structure were systematically studied when the bucket teeth are subjected to different forces in the excavation process. The results show that the residual stress in the weld area is relatively large, and the peak values of the longitudinal residual stress on the key welds of the lugs are located in the arc welding section of the weld. The bucket meets the static load design requirements when the five teeth are evenly stressed. However, when the five teeth are subjected to asymmetrical stress or biased load, the bucket structure will produce greater stress and deformation, and easily lead to early damage and failure of the bucket. The difference of structure stress and deformation between various working conditions increases significantly with the increase of external load, and the maximum stress and deformation are mostly concentrated in the position of the edge teeth of the bucket. This indicates that the edge tooth is the weak part of the bucket structure and liable to be damaged, which is consistent with the feedback results of the field failure cases of this type of bucket. The results provide an important theoretical basis for the subsequent structural design and optimization of the bucket.关键词：bucket;welded structure;welding stress;different working conditions;finite element analysis (FEA)
- 57
- |
- 7
- |
- 0
发布时间：2022-09-15
Important Issuse
- 摘要：The installation of water supply pipeline in urban underground pipe gallery is affected by the on-site working conditions and welding methods, so the laying efficiency of water supply pipeline cannot meet the construction progress. According to the construction conditions and characteristics of all-position ring welding of steel water supply pipeline, the all-position automatic welding system of large-diameter thin-wall steel water supply pipeline was designed and developed. The system consists of adjustable flexible guide rail, walking chassis, welding torch attitude adjustment mechanism and heterogeneous network real-time control system based on EtherCAT high-speed Ethernet. Install the guide rail on the pipeline to be welded, and the welding walking chassis drives the welding torch through the welding torch attitude adjustment mechanism to complete the welding operation according to the pre-set process parameters and welding trajectory. It is applied in the first phase of water supply pipe network in Shijingshan District, Beijing. The results show that the application of automatic pipe welding technology improves the construction efficiency of water supply pipe laying, reduces the labor intensity, and improves the overall quality of the project. It provides engineering application experience for the large-scale promotion of automatic welding of water supply pipeline in urban underground pipe gallery.关键词：urban underground comprehensive pipe gallery;steel water supply pipes;automatic welding of pipes;engineering applications
- 44
- |
- 12
- |
- 0
发布时间：2022-09-15 - 摘要：In order to solve the problems of poor welding quality and low welding efficiency of traditional manual MIG welding of air deflector products and the harm caused by aluminum alloy welding to the welding personnel, the air deflector products of the third generation CAP1400 nuclear power station are introduced and analyzed according to the actual use of aluminum alloy automatic welding process in domestic enterprises. The feasibility of using the aluminum alloy automatic welding process for the air deflector of CAP1400 nuclear power station is evaluated. According to the actual welding requirements, welding test data and specific production conditions, an intelligent equipment and new process suitable for the aluminum alloy welding for the air deflector are developed. The welding quality and production efficiency of the air deflector products are greatly improved to ensure the smooth operation and long-term service of nuclear power equipment. It can provide a reference for the subsequent preparation of nuclear power key parts of aluminum alloy related structures.关键词：aluminum alloy welding;welding robot;automatic welding process;welding deformation
- 44
- |
- 11
- |
- 0
发布时间：2022-09-15
Welding Equipment
- 摘要：Laser cladding of EA4T steel,the phase composition of the heat affected zone was analysed by optical microscopy and scanning electron microscopy. The effect of laser cladding on the microstructure transformation of the heat affected zone of EA4T steel was discussed. The distribution of alloying elements and the micromechanical properties of the interface were measured. The results showed that the microstructure of the heat affected zone (HAZ) of laser cladding EA4T steel was mainly lath martensite. Near the interface area, the homogenization of austenite and the dissolution of carbides were not sufficient, and the grains were coarse. In addition, under laser cladding process conditions, the highest temperature experienced in the heat affected zone of EA4T steel played a decisive role in organizational evolution and mechanical properties. With abrupt changes in alloying elements at the location of the bonding zone, significant grain orientation, shear strength in the heat affected zone increased, but indentation rate reduced.关键词：laser cladding;microstructure;interfacial properties;grain orientation
- 56
- |
- 8
- |
- 0
发布时间：2022-09-15 - 摘要：Based on various thermodynamic models of phase transformation, the thermal model of acicular ferrite transformation in 10Ni5CrMoV steel weld was calculated. The driving force of weld metal transformation was calculated to reveal the mechanism of austenite transforming into acicular ferrite in 10Ni5CrMoV steel weld. The traditional diffusion model, pearlite transformation model and carbon lean zone shear model were used to explore the thermodynamic transformation mechanism. The results show that the lower the carbon contents in the original austenite, the greater the driving force of the acicular ferrite transformation. When the temperature of the austenite transforming into acicular ferrite reduces, the activity of carbon atoms in the carbon poor zone increases, and the growth driving force of acicular ferrite improves, which is conducive to the formation of acicular ferrite. The driving force of acicular ferrite transformation at 700 K was about 6.1 times of that at 950 K. Based on thermodynamic calculation, it is inferred that acicular ferrite is formed mainly in the form of shearing transition in carbon poor zone. It's a better process choice to increase the content of acicular ferrite by prolonging the residence time of medium temperature transformation during welding process.关键词：acicular ferrite;phase transformation thermodynamics;driving force;shear
- 131
- |
- 25
- |
- 0
发布时间：2022-09-15 - 摘要：QT400-18AL is widely used in wind turbines, such as yaw brake disc, generator brake disc, yaw reducer foundation. Cracks and other failures of these components will occur after the wind turbine operates for some time. Thus, repairing them as soon as possible is of great significance. We weld QT400-18AL with a new kind of welding rod LRF-01, and measure the mechanical properties and obtain the results. LRF-01 has its advantages compared to traditional welding rod, such as Z308. Welding defects such as cracks, blowholes are reduced. The mechanical properties of the welding samples can meet the requirements of the wind turbines. LRF-01 can be applied for repairing some components of wind turbines.关键词：QT400-18AL spheroidal graphite cast iron;LRF-01;welding performance;mechanical property;wind turbine
- 60
- |
- 14
- |
- 0
发布时间：2022-09-15 - 摘要：In the welding process, due to the deformation of the material to be welded or the operation error, the stirring needle may be misaligned with the center line of the joint, which may cause an offset, which will adversely affect the quality of the joint. Therefore, it is necessary to study the offset. Use friction stir welding to weld 6005A-T6 hollow aluminum profiles, prepare butt-lap friction stir welding (FSW) joints with different offsets, perform tensile tests and fatigue tests under constant load, and explore the effect of different shaft shoulders on the tensile strength and fatigue performance. The results show that the tensile strength values of the specimens under the offset of the shaft shoulder of the six stirring needles are distributed around 200±10 MPa, which indicates that the influence of the tensile strength is not obvious. By calculating the joint strength coefficients, it is found the butt-lap joint strength coefficients under the shoulder offset are all higher than 0.7, which can be judged as qualified; for the two groups of test pieces with shoulder offset of AS3 mm and RS1.8 mm, when the maximum load value is 55 MPa ,there is no failure under the specified life, and the fatigue performance can be judged to be qualified. Under a larger load, the test specimens all fail within the specified life. The fracture position is the junction of the heat-affected zone and the fusion line, indicating that the position is the stress concentration is greater.关键词：friction stir welding;axial offset;tensile strength;fatigue performance
- 55
- |
- 13
- |
- 0
发布时间：2022-09-15 - 摘要：TIG+SMAW method is used to weld large diameter thick-walled G115 heat-resistant steel pipe used for ultra-supercritical power plant boiler, and the microstructure and mechanical properties of the joint are analyzed. The results show that there are obvious microstructural transformation in weld zone (WZ), heat affected zone (HAZ) and fusion zone. The WZ is mainly composed of tempered martensite microstructure, HAZ is mainly composed of lath martensite microstructure, and base metal appears lamellar martensite microstructure. From the base metal to the weld, the grain gradually refines, the microstructure of weld is mainly equiaxed grain and columnar grain, and the joint hardness distribution gradually increases, but slightly decreases near the fusion line, in which the minimum value of joint hardness is 220.6 HV0.2 (HAZ) and the maximum value is 302.8 HV0.2 (WZ). In addition, the joint impact test shows that the impact absorption energy of the root of HAZ is significantly higher than that of the weld, while that of the filled zone is slightly lower than that of the weld. The average values of the impact absorption energy in WZ and HAZ are 43.89 J and 66.49 J respectively. The impact toughness of the welded joint is good, which can meet the actual application requirements.关键词：G115 heat-resistant steel;arc welding;large diameter thick wall pipe;microstructure;mechanical properties
- 97
- |
- 16
- |
- 0
发布时间：2022-09-15 - 摘要：Laser arc hybrid welding technology is one of the new welding technologies vigorously studied andpromoted by several major manufacturing plants of CRRC in recent years, especially for some shortcomings oftraditional MAG welding of medium and thick plates of railway car bogies. Laser arc hybrid welding has a goodapplication prospect. It has good penetration, small welding heat input and easy deformation control, and has beenapplied in many fields.Combined with the structural characteristics of the laser arc hybrid welding fillet weld ofthe side beam of the railway car bogie, a new process is developed, It solves the technical difficulty that theoriginal detection method cannot 才omprehensivescan the fillet weld of the bogie side beam by laser arc hybridwelding。Ultrasonic testing technology can accurately detect the internal defects of this kind of weld, and realizethe full coverage of the weld, which provides a basis for the rational formulation of nondestructive testingtechnology.关键词：ultrasonic;laser arc hybrid welding;bogie;fillet weld
- 70
- |
- 8
- |
- 0
发布时间：2022-09-15 - 摘要：In view of the four commonly used standards (NB/T 47014-2011, ISO 15614-8:2016, ASME BPVC-IX:2019 and RCC-M S3000:2007) for welding procedure qualification of heat transfer tube and tube sheet at home and abroad, the similarities and differences of their applicable scopes, specimen forms, qualification variables and acceptance criteria are systematically analyzed. The results show that the ISO 15614-8:2016 covers almost every field of welding procedure qualification and is the only standard to distinguish the arrangement of tube sheet. The other three standards only emphasize the number of welded joints. For the ISO 15614-8:2016 and RCC-M S3000:2007, the interstitial structure and expanding process of tube and tube sheet are considered as important variables. However, the fit clearances of tube and tube sheet are not required for the ASME BPVC-IX:2019 and the NB/T 47014-2011. The four standards all have similar requirements for the visual tests, penetrant tests and macro metallographs. Also, only the ISO 15614-8:2016 requires more stringent inspection. By analyzing the difference and application of these standards, it provides the theoretical guidance and technical reference for the welding procedure qualification of heat transfer tube and tube sheet in the future.关键词：heat transfer tube;tube sheet;standard;welding procedure qualification
- 110
- |
- 21
- |
- 0
发布时间：2022-09-15
Welding Technology
- 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