最新刊期
期 10 ， 2023
- 摘要：Metal additive manufacturing combines advanced manufacturing, digital manufacturing, intelligent manufacturing, and green manufacturing, effectively solving the difficulties in traditional casting or forging processes, and is one of the most promising technologies in the field of material processing. However, at present, the consistency and reliability of additive manufacturing product quality still need to be urgently addressed, and testing plays a crucial role in product quality control and runs through additive manufacturing, which can effectively promote the standardization, health, and high-quality development of this technology. This paper mainly describes the research progress of additive manufacturing from the viewpoint of the detection status of raw materials, equipment, process and parts. At the same time, based on the status, the future development trend of additive manufacturing detection is proposed.关键词：metal;additive manufacturing;inspection;application research;development trend
- 55
- |
- 6
- |
- 0
发布时间：2023-11-20 - 摘要：Pack cementation method was used to form aluminized layer on linear friction welded joints of dissimilar titanium alloys, in order to improve the corrosion resistance of joints. The morphology and composition of the aluminized layer of welded joint were analyzed, and the effect and influence of aluminized layer on hot corrosion performance was studied, and the aluminizing process was optimized.Resultsindicate that pack aluminizing is conducive to improving the hot corrosion performance of the joint, and the corrosion weight decreases and the corrosion stability improves after aluminization. The reason is that the corrosion reaction changes before and after aluminizing. Under the environment of high temperature molten salt, the joint directly reacts with the corrosion medium, because the aluminum content of titanium alloy is less, the dense oxide film cannot be formed on the surface. The aluminized joint surface reacts with oxygen to form a dense alumina film, which prevents molten salt and oxygen from eroding into the joint. After hot corrosion for 100 h, the corrosion weight gain of aluminized joint is 0.926 mg/cm2, which is much smaller than 12.478 mg/cm2 without aluminization. The aluminized layer is composed of intermetallic compound TiAl3, and the thickness of the aluminized layer is inconsistent. The TC17 side is thicker than the TA15 side, and the transition is slow in the near field of the weld. The thickness of aluminized layer increases first and then decreases with the increase of holding temperature, and increases gradually with the extension of holding time. After comprehensive consideration, the optimal aluminizing temperature range is 850~950 ℃, and the optimal aluminizing time range is 3~5 h.关键词：aluminized layer;pack aluminizing;linear friction welding;dissimilar titanium alloy joints;hot corrosion
- 33
- |
- 8
- |
- 0
发布时间：2023-11-20 - 摘要：Friction pull plug welding (FPPW) is an important means for high-quality repair of rocket fuel tank manufacturing defects. In current work, FPPW experiments of 6mm thick 2219-T87 aluminum alloy using cylindrical plug hole, arc-shaped plug and supporting plate were carried out at large axial welding force and low rotation speed, and then the weld formation and mechanical properties of the joints were studied. In the given parameter range, The optimal combination of process parameters determined by orthogonal experimental design method is: 4 000 rpm rotation speed, 60 kN axial welding force and 6mm axial feed displacement. The results of metallographic microscope observation and X-ray flaw detection show that under the condition of the above parameters, the weld is well formed, without defects, and the heat affected zone is very small. The tensile test results show that the tensile strength of the joints under the above parameters is 372 MPa, the yield strength is 242 MPa, and the elongation is 4.5%.关键词：friction pull plug welding;optimal processing parameters;weld formation;microstructure;mechanical properties
- 25
- |
- 4
- |
- 0
发布时间：2023-11-20 - 摘要：The microstructures and properties of EBW joint of 30 mm TC4 titanium alloy under two heat treatment conditions of stress relief annealing and full annealing were studied. The results show that the microstructure of the joint is similar under two heat treatment conditions. The BM is mainly composed of equiaxed α phase plus two-phase structure consisting of lath α phase and intercrystalline β phase, and the HAZ is composed of primary α phase, acicular martensite α ′ phase and two-phase structure consisting of lath α phase and intercrystalline β phase. The WM is mainly composed of a large number of acicular martensite α ′ phases and a small number of α phases distributed at the original β grain boundary. In the fully annealed state, the overall organization of the joint is more uniform and higher spheroidization of α phase，stronger tensile strength and weaker impact resistance, compared with the stress relieved annealed state.关键词：Titanium alloy;electron beam welding;stress relief annealing;heat treatment
- 29
- |
- 10
- |
- 0
发布时间：2023-11-20 - 摘要：In order to achieve a reliable connection between copper and titanium dissimilar metals, a heat-assisted ultrasonic welding process method was explored. Firstly, a heat-assisted ultrasonic welding package was built using an MCGS touch screen as the host computer and a ceramic heating pad as the auxiliary heating heat source. Secondly, the human-machine interface and control program developed by MCGS software achieves real-time control of the heat-assisted ultrasonic welding process. Finally, through the analysis of the mechanical properties and microstructure of Cu/Ti ultrasonic welded joints under different heating temperatures, an interface response model of the thermal-assisted ultrasonic welding process was established to explain the formation mechanism of Cu/Ti thermal-assisted ultrasonic welded joints. The analysis of the experimental results shows that the auxiliary heating increases the peak temperature of the weld zone and promotes the mutual diffusion of the interfacial elements, resulting in a significant increase in the width of the reaction zone and the effective joint area, and a significant increase in the mechanical embedding effect, which is the main reason for the significant increase in the shear strength of the Cu/Ti joint.关键词：auxiliary heating;ultrasonic welding;Cu/Ti dissimilar metal joining;joint formation mechanism
- 10
- |
- 3
- |
- 0
发布时间：2023-11-20 - 摘要：Aiming at the multi-layer and multi-pass welding seam of Q690D high strength steel for fully mechanized hydraulic support structural parts, the effects of welding process parameters such as welding current, shielding gas flow, wire extension and assembly gap on the type, position and quantity of weld defects were studied by section analysis and X-ray detection. The joint performance was tested by tensile test and impact test. The results showed that the weld bead were mainly pores, incomplete penetration and incomplete fusion, among which pores account for about 43 %, incomplete penetration accounts for about 30%, and incomplete fusion accounts for about 23%. The defects were mainly concentrated in the root of the weld, the inside of the weld, the fusion line between the weld and the base metal, and between the welds. Among them, the number of weld root defects accounts for about 54%, which was the most concentrated position of weld defects. In the test, welding current, shielding gas flow rate, wire extension and other parameters had a great influence on the internal defects of the weld, but had no obvious influence on the root defects of the weld. The splicing gap had a significant effect on the defects such as incomplete penetration and porosity at the root of the weld. When splicing gap was 2 mm, the root defect could be effectively reduced. The type of shielding gas mainly affected the quality of weld formation, but had no obvious effect on weld defects. After optimizing the process parameters, the weld defects were obviously reduced, and there were no obvious defects such as incomplete penetration and incomplete fusion. The porosity was about 2.1%, the tensile strength of the joint was 798.6 MPa, and the joint performance was good.关键词：Q690D;hydraulic support;welding process parameters;multi-pass welding;welding imperfection
- 15
- |
- 7
- |
- 0
发布时间：2023-11-20 - 摘要：Due to the excellent high-temperature performance and nuclear properties, SiC/SiC composites are one of the candidates for fourth-generation reactor cladding materials. In harsh nuclear environment, it is difficult to manufacture SiC tubes that meet industrial applications, so the preparation and joining need to be studied. In this paper, the current research status of the preparation process (Chemical Vapor Infiltration, Polymer Infiltration and Pyrolysis, and Nano Infiltration and Transient Eutectic) and joining technology (brazing, ceramic precursor connection, nano-impregnation transient liquid phase and glass-ceramics) for nuclear SiC/SiC composites is briefly summarized, and the prospects of SiC/SiC composites in nuclear applications in the future are proposed.关键词：SiC/SiC composites;preparation process;joining technology;nuclear property
- 10
- |
- 2
- |
- 0
发布时间：2023-11-20
Important Issuse
- 摘要：Through the comprehensive use of the analog input and output functions of the data acquisition card and the external trigger function of the high-speed camera, a virtual instrument LABVIEW and high-speed camera equipment are used to develop a set of arc welding parameter acquisition and analysis system, which can analyze the electrical signal information of the welding process. Simultaneous acquisition of droplet transition image information, filtering, statistical analysis, U-I analysis, correlation analysis, FFT transformation, STFT transformation, power spectrum analysis and other time domain and frequency domain analysis of the collected electrical signals. The system is applied to the GMAW (gas metal arc welding) process. By comprehensively analyzing the relationship between the electrical signal and the droplet transfer image and the relationship between the welding current variation coefficient and frequency, the stability of the welding process and the relationship between the electrical parameters and the droplet can be intuitively reflected. The relationship of transition provides a basis for waveform control and droplet transfer control, which is beneficial to optimize the GMAW process.关键词：LabVIEW;arc welding parameter acquisition and analysis system;short circuit transfer;GMAW;electrical signal
- 9
- |
- 5
- |
- 0
发布时间：2023-11-20 - 摘要：As an important link to ensure the welding quality, the post-welding inspection of resistance spot welding joints has been paid much attention in the welding production of stainless steel metro vehicle bodies. At present, the ultrasonic testing technology of spot welding joint quality is mostly qualitative testing, which can't determine the geometric state of nugget, the size of internal defects and other quality information. Therefore, the research on ultrasonic propagation characteristics and its sound field distribution in resistance spot welding joints is carried out, and developed a rapid ultrasonic imaging and evaluation detection system for the internal connection status of stainless steel spot welding joints based on large diameter and dense array element probes. By studying the deep processing technology of ultrasonic signals, we extract geometric information that can represent different connection forms and defects inside the joints, establish a quantitative detection model, and achieve intuitive imaging of the internal connection status of stainless steel spot welding joints and automatic recognition and calculation of nugget size. Through ultrasonic testing experiments, it has been verified that the measured and measured values of the nugget size are in good agreement. The mean of the normal distribution curve is -0.001 87, with a standard deviation of 0.139 2. The mean and variance of the relative error are both very small..关键词：resistance spot welding joint;ultrasonic testing;visual imaging;nugget diameter;quantitative testing
- 8
- |
- 3
- |
- 0
发布时间：2023-11-20
Welding Equipment
- 摘要：As the rapid development of modern electronic technology, the higher requirements of process reliability and soldering quality is needed in the field of microelectronic soldering. At the same time, the increase of product structure precision, the requirements of automatic production and the improvement of processing quality has brought more challenges to the traditional microelectronic welding process. As a new microelectronic connection process, laser soldering has been widely used in many electronic fields. Compared with the traditional soldering process, laser soldering with non-contact, precise temperature controlled heating process has obvious advantages in many process occasions. This paper introduces the basic principle of laser soldering and compares it with traditional soldering, briefly introduces three kings of common laser soldering and the process. The application and process advantages of laser soldering in different electronic packaging fields are illustrated. Meanwhile, typical defect forms and current difficulties in laser soldering process are described in this article.关键词：laser soldering;precision machining;microelectronic welding;application and development
- 14
- |
- 4
- |
- 0
发布时间：2023-11-20 - 摘要：Residual heat removal heat exchanger (PRHX/PRS) is the key equipment in the third generation nuclear island equipment, whose reliability and stability are very important to the safety and economy of the whole nuclear power plant operation. In AP1000, CAP1400 and ACP1000, passive residual row plays a very important role. The design parameters, structure, main materials, main welding contents and key welding techniques of PRHX/PRS are introduced. The technology of tube sheet cladding, welding of head, sealing of tube plate, stainless steel frame and seismic component are introduced. The sealing welding technology of tube and tube plate is a kind of welding process, which adopts the automatic tungsten-argon arc welding process without wire filling. The difficulty of the sealing welding of tube and tube plate is that the thickness of the tube is thin, and improper control in the welding process will cause discontinuous defects at the root of the weld. The welding technology of stainless steel frame and seismic component is an important engineering technology, which has been widely used in many fields. When welding stainless steel frames and seismic components, it is necessary to follow certain technological processes and operating specifications to ensure welding quality and safety.关键词：power;PRHX/PRS;sealing head welding;tube plate sealing welding;sealing welding
- 13
- |
- 2
- |
- 0
发布时间：2023-11-20 - 摘要：A furnace of cracking furnace of ammonia decomposition unit is made of heat-resistant stainless steel-welded, and the partial welded joint cracks in the process of long-term high-temperature operation. In order to ensure the safe production of heat-resistant stainless steel furnace liner, the reason for the occurrence of furnace liner cracks is that S31008 austenitic stainless steel continuously precipitates a network of brittle Cr23C6 carbides along the grain boundary during long-term high-temperature operation. Under the action of working stress, the cracks propagate along the grain boundary, causing fracture along the grain boundary. In addition, the operating temperature of the cracking furnace and the inconsistency in the dimensions of the elliptical head and intermediate nozzle, as well as the intermediate nozzle and tube bundle, cause stress concentration and prevent synchronous shrinkage, resulting in residual tensile stress. Using ER310 welding wire and tungsten argon arc welding for welding repair. After the non-destructive testing of the weld, it was found that the fusion line between the weld and the base metal was clear and regular, the fusion was good, and the furnace liner after welding repair could meet the requirements of normal use.关键词：heat-resistant stainless steel;weld crack;intergranular corrosion;welding repair
- 22
- |
- 5
- |
- 0
发布时间：2023-11-20 - 摘要：Plasma arc welding was adopted to butt welding of 316L austenitic stainless steel and 2205 duplex stainless steel, and the microstructure, mechanical properties and corrosion resistance of the welded joint were analyzed. The results showed that the microstructure of plasma arc welded 316L/2205 dissimilar stainless steel joints was uniform and fine, and being with a certain directionality. The size of austenite and ferrite in the weld zone was larger than that of in the edge area, but was coarsened with increasing the arc current. The overall change trend of the microhardness distribution of the dissimilar stainless steel joints under different currents was consistent. The average tensile strength of the welds reached 533~571 MPa, and all joints fractured on the 316L side. When the arc current was small, the fine and uniform microstructure of the weld ensured high hardness and tensile strength. The self-corrosion potential of the base materials and welds from high to low was joint 75 A > joint 85 A>316L base material>2205 base material>joint 95 A. Increasing the arc current can increase the austenite content in the weld and destroy the grain boundaries, thereby affecting the rate of intergranular corrosion.关键词：plasma arc;dissimilar steel joint;microstructure;mechanical properties;corrosion resistance
- 19
- |
- 5
- |
- 0
发布时间：2023-11-20 - 摘要：In order to improve the performance of FCAW-G pipeline girth weld and provide guidance for the selection of welding materials and process parameters,the effect of metallographic structure and properties under six welding heat inputs were systematically studied,combined with metallographic analysis, tensile test, impact test, CTOD fracture toughness etc.The test results show that the heat input have great influence on the metallographic structure and properties of weld metal.The microstructure of X80 FCAW-G weld metal consists predominantly polygonal ferrite, acicular ferrite(AF) and granular bainite.With the increasing of the heat input, the grains grow up and the acicular ferrite decreases；The low temperature toughness of weld metal increased with the increasing of heat input at first but when heat input reached 1.2 kJ/mm it decreased with the increasing of heat input. Under high heat input, the weld structure coarsened, which led to the decrease of the weld metal strength and fracture toughness.The X80 FCAW-G weld metal with good properties can be obtained with the heat input of 1.2 kJ/mm.关键词：heat input;X80 grade Gas-shield flux cored wire;weld metal;microstructure;properties
- 18
- |
- 6
- |
- 0
发布时间：2023-11-20 - 摘要：In this paper, the welding test of VPTIG1+VPTIG2 cross joint of 2A14-CS state δ 6mm aluminum alloy is carried out by single-side two-layer welding (argon arc backing+argon arc capping) process, and the microstructure and mechanical properties of the cross joint and single VPTIG welded joint are compared. The results show that the tensile strength of cross joint decreases by 5.4%~6.6% compared with that of single VPTIG welded joint; the elongation after fracture decreases by 19.2%~23.6%, and the plasticity decreases more significantly. The hardness of cross joint is consistent with that of single VPTIG welded joint; from the base metal to the weld center, the hardness shows a trend of first decreasing, then locally increasing and then decreasing, but the hardness of the weld zone of the cross joint and the part of the heat affected zone near the weld is significantly lower than that of the single VPTIG welded joint. The microstructure of the cross joint is in the form of dendrite and cellular dendrite. Compared with the single VPTIG welded joint, the grain size of the backing layer cross weld is thicker and unevenly distributed, which leads to the decline of the mechanical properties of the cross joint. The fracture mechanism of cross joint is the same as that of single VPTIG joint, which is a mixed fracture mechanism; that is, grain boundary ductile fracture is the main fracture, accompanied by microcrack source stress propagation crack and microporous polymerization fracture. However, compared with single VPTIG joint, the fracture of cross joint has fewer dimples and is shallow, and the microcrack source has more obvious characteristics of stress propagation cracking.关键词：2A14 aluminum alloy;VPTIG;cross joint;microstructure;mechanical properties
- 14
- |
- 3
- |
- 0
发布时间：2023-11-20 - 摘要：In order to study the effect of different types of shielding gas on the welding pool of continuous laser line welding with low-power fiber laser, SUS304 stainless steel is selected as the test material to compare the jointed appearance and welding pool of continuous laser line wielding under five air blowing modes: no-air blowing, compressed air, N2, Ar, He. The results show that the welding pool obtained by laser welding in the air-blowing mode is more stable with much less defects appearance. The cross section of the molten pool has a special "nail head shape" under the action of the shielding gas. Different types of shielding gases will have a certain impact on the size of the weld pool after welding. Compared with welding without blowing under the test conditions, the average weld width increases by 44.7% and the average penetration increases by 16% under the N2 condition, 55.3% and 8.9% under the Ar condition. Under the He condition, the average weld width increased by 59.6%, and the penetration didn't change much. The difference is caused by the ionization of atmospheric gas and the "blowing heat dissipation effect". In production, considering the welding effect and economic cost, using argon gas as a protective gas is a better choice in low-power precision welding of thin plates.关键词：continuous laser line welding;protective gas;weld appearance;welding pool;blowing heat dissipation effect
- 22
- |
- 7
- |
- 0
发布时间：2023-11-20 - 摘要：The reactor pressure vessel (RPV) belongs to the heart equipment of nuclear power plants,which operates in the environment of high temperature, high pressure, strong corrosion and strong radiation for a long time.The stripping problem of stainless steel overlay is a major problem during RPV manufacturing process, and high cost to handle.In this paper, two stainless steel overlay stripping cases were selected to analyse, which appeared during main bolt holes and top cover sealing surface manufacturing process of “HPR1000” RPV. Through the analysis of influencing factors,the author summarizes 7 key points for welding process in the prevention of overlay stripping, including welding method, welding position, welding parameters, overlap amount, preheating, welding station and operation specifications. This provides a valuable accumulation and engineering experience for the subsequent manufacturing of “HPR1000” RPV.关键词：reactor pressure vessel;overlay;disbonding;process control
- 10
- |
- 3
- |
- 0
发布时间：2023-11-20 - 摘要：Taking 13MnNiMoR steel as the research object, two test coupons were welded respectively with H08Mn2MoA+SJ101 and H09MnNiMoG+SJ16G welding materials. Properties such as microstructure, tensile test, impact tests at -20℃ of two test coupons were analyzed after simulating head hot forming, recovery performance heat treatment, Max.PWHT and Min.PWHT. The results show that H09MnNiMoG wire with SJ16G flux have higher chemical composition of Mn, Ni, Mo in the weld metal, the structure of the weld zone is sostenite and a little amount of ferrite with fine grain, and the tensile properties are better at room temperature and high temperature.关键词：13MnNiMoR;spliced weld of head;welding;mechanical property
- 15
- |
- 3
- |
- 0
发布时间：2023-11-20 - 摘要：The vacuum brazing process of the aluminium alloy staggered finned water cooled radiator is studied, The water immersion ultrasonic instrument was used to measure the brazing rate of the product, the leak detector was used to measure the air tightness of the product, the tensile testing machine was used to measure the strength and elongation of the sample, and the hardness tester was used to measure the Brinell hardness of the sample.The results show that the temperature curve/the clamping moment and the fixture structure have a significant influence on the brazing rate.With the prolongation of the brazing time,the brazing rate show an upward trend, wih the increase of clamping moment,the brazing rate shows an upward trend too,the best moment is 120 N·m,and the fixture structure affect the brazing of the most upper radiator. In the appropriate temperature curve, torque and tooling conditions, the brazing rate can be as high as 90% or more，the qualified rate of leak detection is up to 99%.After vacuum brazing, the mechanical properties of 3003 aluminum alloy decreased, the tensile strength decreased by 27.2%, the non-proportional elongation strength decreased by 34.1%, and the elongation decreased by 6.6%, the hardness decreased by 32.2%.关键词：water cooled radiator;vacuum brazing;aluminium alloy;brazing rate;staggered fin
- 7
- |
- 3
- |
- 0
发布时间：2023-11-20 - 摘要：In response to the current problem of difficulty in repairing and reusing non-magnetic drilling tools, by analyzing the performance characteristics, wear mechanism, and joint damage forms of non-magnetic drilling tools, melting electrode arc surfacing technology was selected to repair the non-magnetic pressure bearing drilling rods with joint wear failure. A metal powder core wire material suitable for repairing the wear and eccentric wear of non-magnetic drilling tool joints was designed, with the brand of LoWare®-NMBU. The results of the welding repair test show that the cladding metal is an iron based austenitic welded structure. After repair, the P550 pressure bearing drill pipe with wear failure has an average tensile strength of 550 MPa at room temperature, an average Brinell hardness of 320 HB, a Charpy impact energy greater than 120 J, and a magnetic permeability less than 1.01, meeting the requirements for the use of non magnetic pressure bearing drill pipes.关键词：non-magnetic drilling tools;hardbanding wire;MIG overlay weld;mechanical property
- 12
- |
- 5
- |
- 0
发布时间：2023-11-20
Welding Technology
- 摘要：According to the development situation of welding personnel qualification management of civil nuclear safety equipment, combined with our own experience in the qualification management of nuclear power special craft personnel, the shortcomings of the management are analyzed, and the rationalization proposals are put forward, in order to provide the communication and discussion for the majority of personnel. With the release of the new HAF603 regulations, after nearly three years of practice, the management mode has been continuously optimized, and the quality of welding personnel qualification management has been improved through various improvement measures. While improving the skill level of welding personnel in the whole industry, the qualification examination cycle and the examination cost of enterprises have been greatly reduced, and the passing rate of welding personnel qualification examination has gradually increased. The continuous improvement of welders' nuclear safety cultural literacy has a positive significance for ensuring the quality of nuclear equipment and the safety of nuclear facilities.关键词：welding personnel;qualification management;optimize management;measures for improvement
- 15
- |
- 2
- |
- 0
发布时间：2023-11-20
Welding Training
- 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