WorldWideScience

Sample records for automatic welding

  1. Portable machine welding head automatically controls arc

    Science.gov (United States)

    Oleksiak, C. E.; Robb, M. A.

    1967-01-01

    Portable weld tool makes weld repairs out-of-station and on the side opposite the original weld. It provides full automatic control of the arc voltage, current, wire feed, and electrode travel speed in all welding attitudes. The device is readily adaptable to commercially available straight polarity dc weld packs.

  2. Development of automatic laser welding system

    International Nuclear Information System (INIS)

    Laser are a new production tool for high speed and low distortion welding and applications to automatic welding lines are increasing. IHI has long experience of laser processing for the preservation of nuclear power plants, welding of airplane engines and so on. Moreover, YAG laser oscillators and various kinds of hardware have been developed for laser welding and automation. Combining these welding technologies and laser hardware technologies produce the automatic laser welding system. In this paper, the component technologies are described, including combined optics intended to improve welding stability, laser oscillators, monitoring system, seam tracking system and so on. (author)

  3. Automatic welding techniques for nuclear power plants

    International Nuclear Information System (INIS)

    Improved type BWRs (ABWR) further heightened the operation properties, safety and economic efficiency as the synthetic characteristics of the plants by simplification and the heightening of performance. Especially, reactor internal pumps (RIP) together with improved control rod driving (CRD) system promoted the simplification of reactor system and the improvement of operation properties and safety. The structures of RIP casing proper and the welded parts, the automatic TIG welder for RIP casings and the nondestructive inspection after the welding, the three-dimensional automatic welding of CRD stubs, the narrow gap welding of flow nozzles and the automatic welding of spent fuel storage racks are reported. The works of exchanging the recirculating pipings in reactors to 316L pipes withstanding SCC by remote automatic welding to reduce the radiation exposure of workers are introduced. The fully automatic TIG welding system for pipings was developed for the purpose of realizing unmanned welding or the welding that does not require skill, and its constitution and the performance are described. (K.I.)

  4. Development of automatic weld strength testing machine

    International Nuclear Information System (INIS)

    In order to improve the testing process and accuracy so as to carry out all the manual works including documentation automatically and effortlessly, an automatic computerised strength testing machine with the latest state-of-art technology, including both the hardware and software was developed. The operator has to only submit the weld to the machine for testing and start the testing process merely by pressing a switch. This paper depicts the salient features of this machine

  5. Orbital welding automatic pressure test by ODA automatic machines is 35 years old

    International Nuclear Information System (INIS)

    Development review of technology and equipment of automatic orbital welding with automatic pressures test of nuclear power stations pipelines and different purpose objects is performed. Welding variants with automatic pressure test and different welding automatic machines are described. Priority of national developments is underlined

  6. Study on the all position automatic pipeline backing weld machine

    Institute of Scientific and Technical Information of China (English)

    Tang Deyu; Feng Biao; Li Chunrun; Niu Huli; Zhang Yongsheng; Zhang Jianhu

    2008-01-01

    As a result of the lower backing weld efficiency, the applying of automatic welding is seriously limited. So a kind of special automatic welder is designed and manufactured for backing weld. This paper introduces the character of the assembled pulse CO2 arc welding machine which has strong penetrability. It specifies the technology of controlling the parameters of all position automatic welding by computer and multi-axis controller. Moreover typical welding proce-dure parameters are provided. It is proved by examination that the economical and practical equipment and technology are suitable for the long-distance transmission pipeline, and it has a good foreground of spreading and applying.

  7. Study on full automatic arc welding machine for spherical tank

    Institute of Scientific and Technical Information of China (English)

    蒋力培; 张甲英; 俞建荣

    2002-01-01

    A full automatic welding machine for spherical tanks' all position multi-layer welds has been developed. This machine is mainly composed of a two-dimension seam tracking system based on microcomputer's memory and a welding tractor as well as rail. The main features of the machine are: while welding the first layer of a seam, its microcomputer system can analyze and store the tracing information from a two-dimension sensor, and control the welding head device to realize two-dimension real time tracing; while welding the second layer up to the top layer of the seam, it can realize two-dimension tracing based on the memorial data, automatically determine the layer number and continually sway the welding head. The welding test shows that the machine has good tracing and welding behavior, and is suitable for spherical tank's all position multi-layer welds.

  8. Automatic all position welding for horizontally fixed tubes by tungsten inert gas arc welding method

    International Nuclear Information System (INIS)

    The welding of fixed tubes is mostly all position welding in restricted places, accordingly much skill is required. The automation of welding is necessary because of the requirement for the reliability of welded joints, the difficulty of securing skilled workers, and welding quality. The development and production of the automatic welders for TIG welding of tubes have been carried out by Mitsubishi Electric Corp., and the application to various purposes was attempted. The TIG welding for the automatic welding of tubes is advantageous, because backside bead can be formed stably, spatter does not arise, welding is stable for every metal, and the mechanism of the automatic welders is simple. But it is not suitable for the welding of zinc-plated tubes, and the rate of deposition is relatively small. It is applied to the welding of boiler tubes, nuclear energy equipments and pipings, chemical equipments and pipings, and aluminum pipings. The specifications and the construction of the TIG tube welders are shown. The preparation of joints and the control of welding conditions are important for guaranteeing the welding results in automatic welding, therefore sufficient consultation with welder makers about these points is required. The welding defects apt to arise are the bad form of backside beads, blowholes, and the insufficient melting of intermediate layers, and the countermeasures to them must be taken. (Kako, I.)

  9. Automatic classification of defects in weld pipe

    International Nuclear Information System (INIS)

    With the advancement of computer imaging technology, the image on hard radiographic film can be digitized and stored in a computer and the manual process of defect recognition and classification may be replace by the computer. In this paper a computerized method for automatic detection and classification of common defects in film radiography of weld pipe is described. The detection and classification processes consist of automatic selection of interest area on the image and then classify common defects using image processing and special algorithms. Analysis of the attributes of each defect such as area, size, shape and orientation are carried out by the feature analysis process. These attributes reveal the type of each defect. These methods of defect classification result in high success rate. Our experience showed that sharp film images produced better results

  10. Geometric model of robotic arc welding for automatic programming

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Geometric information is important for automatic programming of arc welding robot. Complete geometric models of robotic arc welding are established in this paper. In the geometric model of weld seam, an equation with seam length as its parameter is introduced to represent any weld seam. The method to determine discrete programming points on a weld seam is presented. In the geometric model of weld workpiece, three class primitives and CSG tree are used to describe weld workpiece. Detailed data structure is presented. In pose transformation of torch, world frame, torch frame and active frame are defined, and transformation between frames is presented. Based on these geometric models, an automatic programming software package for robotic arc welding, RAWCAD, is developed. Experiments show that the geometric models are practical and reliable.

  11. Automatic monitoring of vibration welding equipment

    Energy Technology Data Exchange (ETDEWEB)

    Spicer, John Patrick; Chakraborty, Debejyo; Wincek, Michael Anthony; Wang, Hui; Abell, Jeffrey A; Bracey, Jennifer; Cai, Wayne W

    2014-10-14

    A vibration welding system includes vibration welding equipment having a welding horn and anvil, a host device, a check station, and a robot. The robot moves the horn and anvil via an arm to the check station. Sensors, e.g., temperature sensors, are positioned with respect to the welding equipment. Additional sensors are positioned with respect to the check station, including a pressure-sensitive array. The host device, which monitors a condition of the welding equipment, measures signals via the sensors positioned with respect to the welding equipment when the horn is actively forming a weld. The robot moves the horn and anvil to the check station, activates the check station sensors at the check station, and determines a condition of the welding equipment by processing the received signals. Acoustic, force, temperature, displacement, amplitude, and/or attitude/gyroscopic sensors may be used.

  12. Automatization of welding for nuclear power equipments and facilities

    International Nuclear Information System (INIS)

    For the requirement of high reliability in the construction of nuclear power plants and the reduction of radiation exposure in the modefying works of existing plants, the automation and remote operation of welding have increased their necessity. In this paper, the present state of the automation of welding for making machines, equipments and pipings for nuclear power plants in Hitachi Ltd. is described, and the aim of developing the automation, the features of the equipments and the state of application to actual plants are introduced, centering around the automation of welding for large structures such as reactor containment vessels and the remote type automatic welding system for pipings. By these automations, the large outcomes were obtained in the improvement of welding quality required for the machines and equipments for atomic energy. Moreover, the conspicuous results were also obtained in case of the peculiar works to nuclear power plants, in which the reduction of the radiation exposure related to human bodies and the welding of high quality are demanded. The present state of the automation of welding for nuclear installations in Hitachi Ltd., the development of automatic welding equipments and the present state of application to actual plants, and the development and application of the automatic pipe working machine for reducing radiation exposure are explained. (Kako, I.)

  13. Automatic system of welding for nuclear fuel rods

    International Nuclear Information System (INIS)

    The welding process of nuclear fuel must be realized in an inert gas environment (He) and constant flow of this. In order to reach these conditions it is necessary to do vacuum at the chamber and after it is pressurized with the noble gas (purge) twice in the welding chamber. The purge eliminates impurities that can provoke oxidation in the weld. Once the conditions for initiating the welding are gotten, it is necessary to draw a graph of the flow parameters, pressure, voltage and arc current and to analyse those conditions in which have been carried out the weld. The rod weld must be free of possible pores or cracks which could provoke rod leaks, so reducing the probability of these failures should intervene mechanical and metallurgical factors. Automatizing the process it allows to do reliable welding assuring that conditions have been performed, reaching a high quality welding. Visually it can be observed the welding process by means of a mimic which represents the welding system. There are the parameters acquired such as voltage, current, pressure and flow during the welding arc to be analysed later. (Author)

  14. Development of Full Automatic External Welding Machine for Annular Welds of Pipeline

    Institute of Scientific and Technical Information of China (English)

    FengBiao; LiChunrun; TangDeyu; ZhangJianhu; ZhangTianli

    2004-01-01

    To meet the demands of rapid development of pipeline constructions in China, a complete set of full automatic external welding machine for annular welds of pipeline and welding procedure have been developed thereof. The system has been applied in the “West-East Pipeline Project” and its performance is proven. With this welding machine the welding parameters can be either preset before or adjusted in real time during the welding process, which avoids the blemishes of same type domestic and international products. Thus it is best propitious to in-situ construction conditions and workers' technical level in China. In this article the development of mechanical and control systems of this product is introduced and typical welding procedure parameters are provided.

  15. Research on key control technologies of all-position automatic welding machine

    Institute of Scientific and Technical Information of China (English)

    Zeng Huilin; Du Zeyu; Ma Jing; Huang Fuxiang

    2009-01-01

    The pipeline all-position automatic welding machine system is a special welding system for automatically welding circumferential joint of pipeline on site, which has been widely used to the long-distance pipeline construction projects due to the advantages of automatic control for welding parameters at all-position, moving speed of bugs and operating. In this paper, the key control technologies of PAWM all-position automatic welding machine (developed by Pipeline Research Institute of CNPC) such as the automatic control system, control software, personal digital assistant (PDA) software and complex programmable logic device(CPLD) program as well as the control method of welding parameter have been described detailedly. With the higher welding quality, higher welding efficiency and lower labor intensity, PAWM all-position automatic welding machine has been successfully applied in many famous pipeline construction projects.

  16. Fully Automatic Spot Welding System for Application in Automotive Industry

    Directory of Open Access Journals (Sweden)

    Peter Puschner

    2015-12-01

    Full Text Available Abstract A Virtual Machine has led to a fully automatic spot welding system. All necessary parameters are created by measuring systems and algorithms running in the Virtual Machine. A hybrid operating circuit allows the Virtual Machine to read the exact process voltage between the tips of the electrodes every 50 µs. Actual welding voltage and current allow for the first time reading process impedance, electric power and total energy being transferred to the spot weld. Necessary energy input is calculated by a calorimetric model after measuring the total thickness of the materials to be welded as soon as the welding gun is positioned at the workpiece. A precision potentiometer implemented in the gun delivers the total material thickness within the 0.1 mm range during the pre-pressure phases. The internal databank of the Virtual Machine controls all essential parameters to guide the total welding process. Special generator characteristics of the welding power unit are created by the Virtual Machine just during the upslope and the welding phases. So the process will be initialized in differentiating the kind of material, mild steel or high strengthen steel. This will affect the kind of energy input and current decrease during the upslope and downslope phases.

  17. Recognition and automatic tracking of weld line in fringe welding by autonomous mobile robot with visual sensor

    International Nuclear Information System (INIS)

    An autonomous mobile robot with visual sensor and four driving axes for welding of pipe and fringe was constructed. The robot can move along a pipe, and detect the weld line to be welded by visual sensor. Moreover, in order to perform welding automatically, the tip of welding torch can track the weld line of the joint by rotating the robot head. In the case of welding of pipe and fringe, the robot can detect the contact angle between the two base metals to be welded, and the torch angle changes according to the contact angle. As the result of tracking test by the robot system, it was made clear that the recognition of geometry of the joint by the laser lighting method and automatic tracking of weld line were possible. The average tracking error was ±0.3 mm approximately and the torch angle could be always kept at the optimum angle. (author)

  18. Passive Visual Sensing in Automatic Arc Welding

    DEFF Research Database (Denmark)

    Liu, Jinchao

    the weld pool, has also prevented the realization of a closed-loop control system for many years, even though a variety of sensors have been developed. Among all the sensor systems, visual sensors have the advantage of receiving visual information and have been drawn more and more attentions. Typical...... possibilities and thoroughly investigated the development of a passive vision system which is only equipped with a single o-the-shelf CCD camera and optical lters, yet capable of extracting sucient information for the control purpose. From the hardware side, we have studies the selection of proper optical lters...

  19. Improvement of automatic weld and productivity in orbital pipe welding; Pipe yosetsu ni okeru saikin no jidoka to kosokuka

    Energy Technology Data Exchange (ETDEWEB)

    Imaizumi, H.

    1996-09-01

    This paper presents the trend of automatic pipe welding technology and high-speed welding for resolving a lack and aging of welding engineers. In pipe TIG arc automatic welding, precise motor servo control and reproducibility are required to secure ideal penetration bead welding, and such requirements have already beeb satisfied since 20 years ago. However, in MAG welding, since heat gain too high delays cooling of metal melt and causes undercut on the inner wall of pipes, the above requirements are very difficult to be satisfied except the thick pipe for which cooling copper strips are available as inner backing. The proper welding effect was thus obtained by widely controlling the output waveform of welding machines to secure the same heat gain as TIG arc welding. Favorable penetration bead welding was thus achieved even for thin pipes. In order to cope with automatic welding needs in the clearance between thin pipes, specifications of welding heads were subdivided, and a power source unit, computer control unit and cooling water circulation unit were integrated for automation. 7 figs., 7 tabs.

  20. Automatic welding detection by an intelligent tool pipe inspection

    Science.gov (United States)

    Arizmendi, C. J.; Garcia, W. L.; Quintero, M. A.

    2015-07-01

    This work provide a model based on machine learning techniques in welds recognition, based on signals obtained through in-line inspection tool called “smart pig” in Oil and Gas pipelines. The model uses a signal noise reduction phase by means of pre-processing algorithms and attribute-selection techniques. The noise reduction techniques were selected after a literature review and testing with survey data. Subsequently, the model was trained using recognition and classification algorithms, specifically artificial neural networks and support vector machines. Finally, the trained model was validated with different data sets and the performance was measured with cross validation and ROC analysis. The results show that is possible to identify welding automatically with an efficiency between 90 and 98 percent.

  1. Feature extraction and classification in automatic weld seam radioscopy

    International Nuclear Information System (INIS)

    The investigations conducted have shown that automatic feature extraction and classification procedures permit the identification of weld seam flaws. Within this context the favored learning fuzzy classificator represents a very good alternative to conventional classificators. The results have also made clear that improvements mainly in the field of image registration are still possible by increasing the resolution of the radioscopy system. Since, only if the flaw is segmented correctly, i.e. in its full size, and due to improved detail recognizability and sufficient contrast difference will an almost error-free classification be conceivable. (orig./MM)

  2. Improvement of weld material for automatic or semi-automatic welding of creep resistant steel casting compared with manual arc welding. Project D37

    International Nuclear Information System (INIS)

    In cooperation with the projects CH7, D16 and D36 (leadership), project D37 deals with the evaluation of the low cycle fatigue (LCF) behaviour of improved welded joints of heat resistant 1 CrMoV-cast steel (GS-17 CrMoV 5 11). The aim of the whole project is the qualification of automatic welding techniques as shielded metal arc (SMA) and submerged arc (SA) compared to manual arc (MA) and the determination of the optimum postweld heat treatment in respect to sufficient properties. LCF-tests, carried out at 550 C and at total strain ranges of 0, 3 to 2% show that the different welding techniques (MA, SMA, SA) and postweld heat treatments (tempering, hardening, diffusion annealing) result in a common scatterband. All investigated variants seem to have sufficient LCF-properties for practical purpose. (orig.)

  3. Automatic control system of high precision welding of workpieces in mechanical engineering

    Science.gov (United States)

    Kuznetsov, I. N.; Zvezdin, V. V.; Israfilov, I. H.; Portnov, S. M.

    2014-12-01

    In this paper, based on the conducted patent research, the system of laser welding control with different geometry of weld and shapes of parts is developed. The method of monitoring the position of the spot of laser radiation in relation to the curved weld is worked out; it is based on the tracking the edges of the welded parts by low-power laser radiation reflected from the surface of the parts. It allows to make the positioning of the focus of laser radiation in relation to the juncture of the welded parts automatically.

  4. Application of AMI 207A automatic welding to the erection engineering of electric instrument tube of nuclear powre plant

    International Nuclear Information System (INIS)

    The industrial application of automatic, intelligent and high-precision parameter-controlled welding equipment has become true long age in the western developed countries. However, this kind of equipment has been seldom used in China, especially on the erection site of nuclear power construction. In the Phase III of Qinshan Nuclear Power Project, we used the American AMI (Arc Machines, Inc.) 208A automatic welding equipment and technology to have all grooves of the electric instrument tubes automatically welded. The practice has proved that the automatic welding is more advanced, highly effective and more economic compared with other welding processes. (authors)

  5. Automatic meshing method for optimisation of the fusion zone dimensions in Finite Element models of welds

    OpenAIRE

    DECROOS Koenraad; OHMS Carsten; Petrov, Roumen; Seefeldt, Marc; Verhaeghe, Frederik; Kestens, Leo

    2013-01-01

    A new method has been designed to automatically adapt the geometry of the fusion zone of a weld according to the temperature calculations when the thermal welding heat source parameters are known. In the material definition in a Finite Element code for welding stress calculations, the fusion zone material has different properties than the base material since, among others, the temperature at which the material is stress free is the melting temperature instead of room temperature. In this work...

  6. Development of an automatic spacer-pad welding machine for PHWR fuel fabrication

    International Nuclear Information System (INIS)

    A welding machine with an indigenous microprocessor-based electronic controller to automatically weld the spacer-pads for PHWR fuel fabrication has been designed and developed at Nuclear Fuel Complex and put into regular production work. This paper presents its salient features

  7. Automatic welding technologies for long-distance pipelines by use of all-position self-shielded flux cored wires

    Directory of Open Access Journals (Sweden)

    Zeng Huilin

    2014-10-01

    Full Text Available In order to realize the automatic welding of pipes in a complex operation environment, an automatic welding system has been developed by use of all-position self-shielded flux cored wires due to their advantages, such as all-position weldability, good detachability, arc's stability, low incomplete fusion, no need for welding protective gas or protection against wind when the wind speed is < 8 m/s. This system consists of a welding carrier, a guide rail, an auto-control system, a welding source, a wire feeder, and so on. Welding experiments with this system were performed on the X-80 pipeline steel to determine proper welding parameters. The welding technique comprises root welding, filling welding and cover welding and their welding parameters were obtained from experimental analysis. On this basis, the mechanical properties tests were carried out on welded joints in this case. Results show that this system can help improve the continuity and stability of the whole welding process and the welded joints' inherent quality, appearance shape, and mechanical performance can all meet the welding criteria for X-80 pipeline steel; with no need for windbreak fences, the overall welding cost will be sharply reduced. Meanwhile, more positive proposals were presented herein for the further research and development of this self-shielded flux core wires.

  8. Development of Full Automatic Flash Butt Welding with Digital Control

    Institute of Scientific and Technical Information of China (English)

    WANG Rui; SUN Hexu; WANG Hongwen

    2006-01-01

    The hardware and software design of two digital control systems based on 80C196KB MCU for flash butt welder is introduced in this paper. The welding power supply is made of six-phase half-wave rectifier. The welding outer characteristic of welding machine is realized by digital PI algorithm with the voltage close-loop feedback. The flashing curve is finished by electric-hydraulic servo valve .The process control system transfers datum with power supply system by a serial communication interface. The parameters of the control systems are collected by photoelectrical seclusion to avoid the disturbing of the electromagnetism in welding process.

  9. Sensor for automatic welding; Sensor ga yosetsu jidoka wo kirihiraku

    Energy Technology Data Exchange (ETDEWEB)

    Sugitani, Y. [NKK Corp., Tokyo (Japan)

    1998-05-01

    This paper explains sensors in welding automating systems, and introduces examples of sensor technologies. Roles of sensors in the automating systems include stabilization of welding phenomena, in-process control of welding processes, remote surveillance for quality assurance, complementing of robot teaching operation, and remote surveillance for operating conditions to control production. Types of sensors that are used most frequently are arc sensors, electrode contact sensors, and probe contact sensors, followed by photo-sensors and electromagnetic sensors. The arc sensor uses welding arc itself as a sensor, being incorporated in most of arc welding robots. A laser sensor irradiates laser light onto an object, and detects reflected light by using a light receiving element to recognize position and shape of the object. For vision sensors, a technology is advancing, which utilizes a CCD camera to detect root gap, molten pond shapes, electrode tip shapes, and arc shapes. 5 refs., 13 figs.

  10. Effect of orbital automatic welding on the weld metal mechanical properties in API 5L X65 natural gas transmission pipe

    Energy Technology Data Exchange (ETDEWEB)

    Baek, J.-H.; Kim, Y.-P.; Kim, W.-S. [Korea Gas Corp., Ansan (Korea, Republic of)

    2000-07-01

    Most natural gas transmission pipelines in Korea have been constructed using a manual welding processes but major gas companies are looking into the advantages of an automatic process for girth welding. The automatic welding process is divided into gas tungsten arc welding (GTAW) and gas-metal-arc welding (GMAW) processes. GTAW uses an inert gas such as argon to shield weld metal from the atmosphere during welding and a 0.9-1.6 mm solid wire. Filler metals used in the GMAW process are classified into solid wire and flux cored wire. In this study, Charpy impact tests, crack tip opening tests and micro-hardness tests were conducted on a steel pipeline to determine the effects of weld metal composition and microstructure on the toughness of weld metal. API 5L X65 steel pipes with 17.5 mm wall thickness and 762 mm outer diameter were welded using an orbital automatic welding process. Flux cored arc welding (FCAW) and GTAW were used to evaluate the automatic welding process. Manual welds were done using GTAW with ER70S-G filler metal for the root pass and shielded metal arc welding with low hydrogen E9016-G electrode for the remaining passes. It was concluded that the filler metals with the highest fracture toughness were E80T1-K2 and E71T-1 using the FCAW process and ER80S-G using the GTAW process. The filler metals with the correct hardness were E800T1-K2 and E71T-1 using the FCAW process. 13 refs., 3 tabs., 4 figs.

  11. Automatic welding of stainless steel instrumentation tubing in a nuclear power station

    International Nuclear Information System (INIS)

    Impulse lines and sample lines associated with instrumentation systems are of pipes and tubes. For this purpose, stainless steel tubes are employed in CANDU type reactors. For joints, wherever necessary, welding is preferred to tube fittings as far as possible. Welding is less costly, requires less space and is less likely to be disturbed by the operator. For welding, an automatic weld machine is used. Essential parts of this machine, namely, power supply, logic circuits, speed control unit, handle, weld head, high frequency unit, pendant box, recorder and gas system are described. Sequence of operation is explained. Procedures of machine testing, quality control and inspection, and maintenance problems are given. Qualifications for operator are enumerated. Problems in maintenance are reported. (M.G.B.)

  12. On detection and automatic tracking of butt weld line in thin wall pipe welding by a mobile robot with visual sensor

    International Nuclear Information System (INIS)

    An automatic pipe welding mobile robot system with visual sensor was constructed. The robot can move along a pipe, and detect the weld line to be welded by visual sensor. Moreover, in order to make an automatic welding, the welding torch can track the butt weld line of the pipes at a constant speed by rotating the robot head. Main results obtained are summarized as follows: 1) Using a proper lighting fixed in front of the CCD camera, the butt weld line of thin wall pipes can be recongnized stably. In this case, the root gap should be approximately 0.5 mm. 2) In order to detect the weld line stably during moving along the pipe, a brightness distribution measured by the CCD camera should be subjected to smoothing and differentiating and then the weld line is judged by the maximum and minimum values of the differentials. 3) By means of the basic robot system with a visual sensor controlled by a personal computer, the detection and in-process automatic tracking of a weld line are possible. The average tracking error was approximately 0.2 mm and maximum error 0.5 mm and the welding speed was held at a constant value with error of about 0.1 cm/min. (author)

  13. Automatic welding technologies for long-distance pipelines by use of all-position self-shielded flux cored wires

    OpenAIRE

    Zeng Huilin; Wang Changjiang; Yang Xuemei; Wang Xinsheng; Liu Ran

    2014-01-01

    In order to realize the automatic welding of pipes in a complex operation environment, an automatic welding system has been developed by use of all-position self-shielded flux cored wires due to their advantages, such as all-position weldability, good detachability, arc's stability, low incomplete fusion, no need for welding protective gas or protection against wind when the wind speed is 

  14. Boosting Active Contours for Weld Pool Visual Tracking in Automatic Arc Welding

    DEFF Research Database (Denmark)

    Liu, Jinchao; Fan, Zhun; Olsen, Søren Ingvor;

    2015-01-01

    Detecting the shape of the non-rigid molten metal during welding, so-called weld pool visual sensing, is one of the central tasks for automating arc welding processes. It is challenging due to the strong interference of the high-intensity arc light and spatters as well as the lack of robust...... approaches to detect and represent the shape of the nonrigid weld pool. We propose a solution using active contours including an prior for the weld pool boundary composition. Also, we apply Adaboost to select a small set of features that captures the relevant information. The proposed method is applied to...... weld pool tracking and the presented results verified its feasibility....

  15. 可夹持焊枪的氩弧焊自动焊接装置%Argon Arc Welding Automatic Welding Device with Clamping Welding Torch

    Institute of Scientific and Technical Information of China (English)

    张春红; 高开熠; 张宁; 常浩; 陈志伟

    2014-01-01

    针对人工焊接时由于焊接接头的熔深不同、焊缝宽度不同以及焊缝各处差异等人为因素所导致的焊接缺陷,设计了一种可夹持焊枪的氩弧焊自动焊接装置。介绍了可夹持焊枪的氩弧焊自动焊接装置的机械结构、控制模块及功能。该装置保证了稳定的焊接速度和焊接高度,实现了焊枪的三维移动和焊接过程的自动化,提高了焊接效率和焊接质量。利用此装置进行氩弧熔覆耐磨复合涂层的验证试验,试验结果表明该装置可实现组织均匀且与基底实现冶金结合的复合涂层,熔覆层硬度是基体Q235钢的6.4倍,耐磨性和表面质量良好。%During manual welding, aiming at the different fusion of welded joint, weld seam width and weld difference etc. factors which can cause welding defects, a kind of argon arc automatic welding device with clamping welding torch was designed. In this article, it introduced mechanical structure, control module and function of this device. This device can ensure stable welding speed and welding height, realize three-dimension movement of welding torch and welding process automation, and can increase welding efficiency and welding quality. Using this device to conduct verification test for argon arc cladding wear-resistant composite coating, the test results showed that the device can realize uniform organization and base metallurgical bonding confound coating, the coating layer hardness is 6.4 times that of the substrate Q235 steel, wear resistance and surface quality are good.

  16. Team collaborative innovation management based on primary pipes automatic welding project

    International Nuclear Information System (INIS)

    The welding quality of primary pipe directly affects the safe operation of nuclear power plants. Primary pipe automatic welding, first of its kind in China, is a complex systematic project involving many facets, such as design, manufacturing, material, and on-site construction. A R and D team was formed by China Guangdong Nuclear Power Engineering Co., Ltd. (CNPEC) together with other domestic nuclear power design institutes, and manufacturing and construction enterprises. According to the characteristics of nuclear power plant construction, and adopting team collaborative innovation management mode, through project co-ordination, resources allocation and building production, education and research collaborative innovation platform, CNPEC successfully developed the primary pipe automatic welding technique which has been widely applied to the construction of nuclear power plant, creating considerable economic benefits. (authors)

  17. Automatic inspection of electron beam weld for stainless steel using phased array method

    International Nuclear Information System (INIS)

    The CEA laboratory of Non destructive testing of Valduc implements various techniques of controls (radiography, sealing by tracer gas helium, ultrasounds...) to check the quality of the welding and health matter of materials. To have a perfect command of the manufacture of the welding and to detect any anomaly during the manufacturing process (lacks of penetration, defects of joining, porosities...), it developed in partnership with company METALSCAN an ultrasonic technique of imagery phased array designed to the complete and automatic control of homogeneous stainless steel welding carried out by electron beam. To achieve this goal, an acoustic study by simulation with software CIVA was undertaken in order to determine the optimal characteristics of the phased array probes (their number and their site). Finally, the developed method allows, on the one hand, to locate lacks of fusion of welding equivalents to flat holes with bottom 0,5 mms in diameter, and on the other hand, to detect lacks of penetration of 0,1 mm. In order to ensure a perfect reproducibility of controls, a mechanical system ensuring the setting in rotation of the part, allows to inspect the whole of the welding. The results are then analyzed automatically using application software ensuring the traceability of controls. The method was first of all validated using parts spread out, then it was brought into service after confrontation of the results obtained on real defects with other techniques (metallographic radiography and characterizations). (authors)

  18. Fully-automatic laser welding and micro-sculpting with universal in situ inline coherent imaging

    CERN Document Server

    Webster, Paul J L; Ji, Yang; Galbraith, Christopher M; Kinross, Alison W; Van Vlack, Cole; Fraser, James M

    2014-01-01

    Though new affordable high power laser technologies make possible many processing applications in science and industry, depth control remains a serious technical challenge. Here we show that inline coherent imaging, with line rates up to 312 kHz and microsecond-duration capture times, is capable of directly measuring laser penetration depth in a process as violent as kW-class keyhole welding. We exploit ICI's high speed, high dynamic range and robustness to interference from other optical sources to achieve fully automatic, adaptive control of laser welding as well as ablation, achieving micron-scale sculpting in vastly different heterogeneous biological materials.

  19. Automatic laser welding and milling with in situ inline coherent imaging.

    Science.gov (United States)

    Webster, P J L; Wright, L G; Ji, Y; Galbraith, C M; Kinross, A W; Van Vlack, C; Fraser, J M

    2014-11-01

    Although new affordable high-power laser technologies enable many processing applications in science and industry, depth control remains a serious technical challenge. In this Letter we show that inline coherent imaging (ICI), with line rates up to 312 kHz and microsecond-duration capture times, is capable of directly measuring laser penetration depth, in a process as violent as kW-class keyhole welding. We exploit ICI's high speed, high dynamic range, and robustness to interference from other optical sources to achieve automatic, adaptive control of laser welding, as well as ablation, achieving 3D micron-scale sculpting in vastly different heterogeneous biological materials. PMID:25361318

  20. Hardware-software system for the automatic quality evaluation of a welded joint

    International Nuclear Information System (INIS)

    The automatic digital processing of radiographic images has advantages over conventional methods employing x-ray television or x-ray films and an operator as the decision-maker. These advantages are primarily the elimination of subjectivity in the operator evaluation of flaws (so that the result of expert examination is presented to the customer in terms that preclude arbitrary interpretation), the possibilities of using morphological analysis, and the production of a large active data base of flaw images. The authors describe a system that incorporates an optical scanner, a videographic adapter with a graphic monitor, a personal computer, and a software package implementing the functions of automatic analysis of a static-test radiographic image of a welded joint, viz., input and storage of the radiographic image, optimal linear and nonlinear filtering of the primary image to produce a reliable flaw map, and the assignment of weld flaws to four classes: voids, cracks, nonbond flaws, and inclusions. 7 refs

  1. Automatic Optimization of Focal Point Position in CO2 Laser Welding with Neural Network in A Focus Control System

    DEFF Research Database (Denmark)

    Gong, Hui; Olsen, Flemming Ove

    designed and built to automatically optimize the focal point position, one of the most important parameters in CO2 laser welding, in order to perform a desired deep/full penetration welding. The control system mainly consists of a multi-axis motion controller - PMAC, a light sensor - Photo Diode, a data...... acquisition card - DAQCard-700, and a self-learning mechanism - Neural Network. The optimization procedure starts with the welding process being carried out by continuously moving the focal point position from above a welding plate to below the plate, thus the process is ensured to be shifted from initially...... surface welding to deep/full penetration welding and back to surface welding again. A clear change on plasma brightness from the process is monitored by the photo diode on the front side of the plate with a viewing angle of 45o. The photo diode signal is acquired with the A/D converter card and installed...

  2. The effect of electrode vertex angle on automatic tungsten-inert-gas welds for stainless steel 304L plates

    International Nuclear Information System (INIS)

    The effect of electrode vertex angle on penetration depth and weld bead width, in automatic tungsten-inert-gas (TIG) dcsp bead-on-plate welding with different currents, has been studied for stainless steel 304L plates 1.5 mm and 8 mm thick. It has been found that for thin plates, wider and deeper welds are obtained when using sharper electrodes while, for thick plates, narrower and deeper welds are produced when blunt electrodes (vertex angle 180 deg) are used. An explanation of the results, based on a literature survey, is included

  3. Automatic system of welding for nuclear fuel rods; Sistema automatico de soldadura para barras de combustible nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Romero G, M; Romero C, J. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)

    1998-07-01

    The welding process of nuclear fuel must be realized in an inert gas environment (He) and constant flow of this. In order to reach these conditions it is necessary to do vacuum at the chamber and after it is pressurized with the noble gas (purge) twice in the welding chamber. The purge eliminates impurities that can provoke oxidation in the weld. Once the conditions for initiating the welding are gotten, it is necessary to draw a graph of the flow parameters, pressure, voltage and arc current and to analyse those conditions in which have been carried out the weld. The rod weld must be free of possible pores or cracks which could provoke rod leaks, so reducing the probability of these failures should intervene mechanical and metallurgical factors. Automatizing the process it allows to do reliable welding assuring that conditions have been performed, reaching a high quality welding. Visually it can be observed the welding process by means of a mimic which represents the welding system. There are the parameters acquired such as voltage, current, pressure and flow during the welding arc to be analysed later. (Author)

  4. Automatic ultrasonic testing for welding structures; Choonpa ni yoru yosetsu kozobutsu no kensa no jidoka

    Energy Technology Data Exchange (ETDEWEB)

    Yokono, Y. [Non-Destructive Inspection Co. Ltd., Osaka (Japan)

    1998-09-05

    Ultrasonic flow detection when compared with the radiation transmission detection, has advantages such as: it can be used even in thick plate, detection performance of surface defects like cracks or bad unification and so forth is good, possesses easier safety management and so forth. On the other hand, it is a manual testing and lacks memory, and has problem that the test results depend on the ability of technician and automation is preferred in many field. However, the manual scanning method of probe carried out by experienced technicians can not be replaced by automation because the signals obtained depend greatly on the surface condition of specimen, scanning speed of probe and welding pressure. At present, the memory capacity and computation ability of computer have been significantly developed and image processing and photo taking of the obtained results are carried out easily. In this report, practical image of ultrasonic flow detection of weld portion is discussed and some practical examples of automatic test devices for welding structures are introduced. 16 refs., 6 figs., 1 tab.

  5. Remotely controlled semi-automatic welding of two revolution symmetrical pieces

    International Nuclear Information System (INIS)

    The welding is controlled from a control station situated at some distance from the welding zone. The welding parameters are fixed before the welding pass by an operator from values furnished by a memory in which the appropriate parameters are stored. After control of these parameters the welding operation is initiated. The welding operation is constantly observed on a remotely placed screen. The welding parameters may be adjusted by the operator in accordance with the image observed. These modifications are controlled by comparison with the memory content

  6. Automatic hot wire GTA welding of pipe offers speed and increased deposition

    Energy Technology Data Exchange (ETDEWEB)

    Sykes, I.; Digiacomo, J. [Astro Arc Polysoude, Sun Valley, CA (United States)

    1995-07-01

    Heavy-wall pipe welding for the power and petrochemical industry must meet code requirements. Contractors strive to meet these requirements in the most productive way possible. The challenge put to orbital welding equipment manufacturers is to produce pipe welding equipment that cost-effectively produces code-quality welds. Orbital welding equipment using the GTA process has long produced outstanding quality results but has lacked the deposition rate to compete cost effectively with other manual and semiautomatic processes such as SMAW, FCAW and GMAW. In recent years, significant progress has been made with the use of narrow-groove weld joint designs to reduce weld joint volume and improve welding times. Astro Arc Polysoude, an orbital welding equipment manufacturer based in Sun Valley, Calif., and Nantes, France, has combined the hot wire GTAW process with orbital welding equipment using a narrow-groove weld joint design. Field test results show this process and procedure is a good alternative for many heavy-wall-pipe welding applications.

  7. 铝合金桁架环缝自动焊机的研制%Design and manufacture of automatic circumferential welding equipment for aluminium alloy boom

    Institute of Scientific and Technical Information of China (English)

    田松亚; 封艳

    2012-01-01

    根据铝合金桁架铝合金管材与接头环缝焊接要求,设计并制造了一台专用焊接设备.根据焊接时序要求,采用可编程控制器实现对焊接设备逻辑顺序的控制,并制定了铝合金桁架铝合金管材与接头环缝的惰性气体保护焊MIG自动焊接工艺.结果表明,该焊机自动化程度高、性能稳定、操作简便,能够满足铝桁架铝合金管材与接头环缝自动焊生产要求,同时提高了生产率.依据制定的焊接工艺,进行了焊接试验.焊接试验表明,制定的工艺所获得的铝合金桁架铝合全管材与接头对接接头,满足焊缝质量要求.%According to the requirements of aluminium alloy boom circumferential welding,this paper design and manufacture a special automatic welding equipment.In terms of weld time sequence requirement,PLC is used to implement the control of welding device logical subsequence.besides.work out the MIG automatic welding procedure of circumferential welding.The Result shows that the welding device displays high degree of automation,stable performance and convenient movement,which could satisfy production requirements of aluminium alloy boom automatic circumferential welding and improve productivity .Based on the welding procedure, welding experiment is done.The result indicates that welding procedure could reach the quality requirements of welding joint.

  8. Development of automatic multi-layer welding technology for application to a crushing machine; Hasaikiyo atsuita taso yosetsu no jidoka gijutsu no kakuritsu

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, M.; Kosai, K.; Oguro, T.; Yamaguchi, S.; Iizuka, T.; Nihei, K. [Kawasaki Heavy Industries, Ltd., Kobe (Japan)

    1999-12-01

    The primary crushing machine Jaw Crusher has to withstand severe stress in use. The welded-structure frame is composed of steel plates with thicknesses varying between 40 and 120mm. This particular welding task takes time and requires great skill. The authors developed automatic techniques and tools for this work, utilizing a welding robot system. Resulting figures indicating the suitability of welded joints were analyzed from the fatigue strength. Further non-manned robot systems to perform complimentary functions were also developed, such as for slag removal. (author)

  9. Feasibility study of inside automatic welding system of cooling pipe of divertors for FER

    International Nuclear Information System (INIS)

    In order to replace divertors for FER, cooling pipes of divertors should be cut and welded since they are too long to be replaced with divertors via horizontal maintenance ports. An inside cutting and welding system is also required because of an accessibility to pipes. A combination of an inside disc-cutting machine and an inside TIG-welding machine has been proposed as a candidate of the systems. We have made tests to confirm possibility to weld pipes which were cut with the disc-cutting machine. Possibility of welding has been proven. The tests result is described in the paper. (orig.)

  10. An automatic approach for nondestructive radiographic inspection of pipeline weld joint; Uma abordagem automatica aplicada a inspecao radiografica nao-destrutiva de soldas em tubulacoes

    Energy Technology Data Exchange (ETDEWEB)

    Felisberto, Marcelo K.; Schneider, Guilherme A.; Centeno, Tania M.; Arruda, Lucia V.R. de [Centro Federal de Educacao Tecnologica do Parana, Curitiba, PR (Brazil). CPGEI - Programa de Pos-graduacao em Engenharia Eletrica e Informatica Industrial

    2005-07-01

    The current work contributes to the research in the area of pipelines non-destructive testing by presenting new methodologies for the automatic analysis of welds radiographs. Object recognition techniques based on genetic algorithms were used for the automatic weld bead detection. In addiction, an image digital filter was also tested in the weld bead images and, as a result, supposed defects are highlighted, making them easier to be detected. These methodologies were tested for 120 digital radiographs from carbon steel pipeline welded joints. These images were acquired by a storage phosphor system, using double-wall radiographic exposing technique with single-wall radiographic viewing, according to the ASME V code. As a result, even human vision hard-perceptible defects are automatically highlighted and extracted from the whole image to be separately analyzed. (author)

  11. Robotic and automatic welding development at the Marshall Space Flight Center

    Science.gov (United States)

    Jones, C. S.; Jackson, M. E.; Flanigan, L. A.

    1988-01-01

    Welding automation is the key to two major development programs to improve quality and reduce the cost of manufacturing space hardware currently undertaken by the Materials and Processes Laboratory of the NASA Marshall Space Flight Center. Variable polarity plasma arc welding has demonstrated its effectiveness on class 1 aluminum welding in external tank production. More than three miles of welds were completed without an internal defect. Much of this success can be credited to automation developments which stabilize the process. Robotic manipulation technology is under development for automation of welds on the Space Shuttle's main engines utilizing pathfinder systems in development of tooling and sensors for the production applications. The overall approach to welding automation development undertaken is outlined. Advanced sensors and control systems methodologies are described that combine to make aerospace quality welds with a minimum of dependence on operator skill.

  12. 双焊炬自动焊焊接接头CTOD断裂韧性试验研究%Research on Welding Joint CTOD Fracture Toughness by Double Welding Torch Automatic Welding

    Institute of Scientific and Technical Information of China (English)

    方总涛; 李春润; 牛虎理; 胡艳华

    2014-01-01

    According to the fracture toughness test standard of BS7448, the CTOD at low temperature(5℃) of X65 steel double welding torch automatic welding joint with natural cooling and spray cooling was tested respectively. Taking specimen with size of B×2B (B for specimen thickness), and notch direction for NP to conduct three point bending test, and then formed P-V curve of weld and HAZ to calculate the CTOD value, and compared the welding joint CTOD values of natural air cooling and spray cooling. The result showed that spray after welding has no significant influence on CTOD value;this test method provides reference evidence for selecting welding method, welding specification parameters and spraying process parameters.%根据BS7448断裂韧度试验标准,分别对海洋管线用X65钢双焊炬自动焊焊接接头自然冷却和喷淋冷却的低温(5℃)裂纹尖端张开位移(CTOD)进行了测试。取尺寸为B×2B(B为试样厚度),缺口方向为NP的试样进行三点弯曲试验,然后由所得到的焊缝和热影响区(HAZ)的P-V曲线来计算CTOD值,并对比自然空冷和喷淋冷却的焊接接头 CTOD 值。结果表明,焊后喷淋对CTOD值没有显著影响。该试验结果为焊接方法、焊接规范参数和喷淋工艺参数的选择提供了参考依据。

  13. 罐体自动焊设备研究及新型探臂焊车研制%Study on automatic welding equipment for the tankage and developme nt of welding tractor supported on an arm

    Institute of Scientific and Technical Information of China (English)

    杨国栋; 张乃键; 高艺松

    2001-01-01

    对罐体、筒类零件的自动焊接设备的分类、结构特点及使用情况进行了分析和研究。介绍了新型探臂式自动焊车的设计思路、结构特点及研制过程。探臂式自动焊车的研制成功为筒类零件的纵缝气体保护焊和埋弧焊提供了先进的新型焊接设备。%The classifacations,features and applications of automatic welding equipment used in jar and tube-shaped workpieces are analyse d and studied.Also the design idea, structures and the development process of a new arm type automatic welding carriage are introduced.And with the successful devel opment of this arm type automatic welding carriga,an advanced welding equipment for vertical seam gas shielded welding and submerged-arc welding of tube-shape d workpieces is appeared.

  14. 焊缝形貌对埋弧焊缝自动超声波探伤结果的影响分析%Analysis on Effect of Weld Profile on Submerged Arc Weld Automatic Ultrasonic Testing Results

    Institute of Scientific and Technical Information of China (English)

    桂光正

    2011-01-01

    The weld internal quality of double side submerged arc welding is mainly detected by automatic ultrasonic testing system. In this article, it introduced weld automatic ultrasonic testing equipment and weld tracking principle which was imported from the abroad and used in production line. Through analysis on structure of sampled pipe detected by ultrasonic testing, it explained effect factors to the accuracy of ultrasonic testing results from several aspects, such as outside weld profile, inside and outside weld width, center misalignment of inside and outside weld, anomaly weld profile resulted from edge offset, and so on. Finally, it gave measures and methods of improving ultrasonic testing accuracy for submerged arc welded pipe.%双面埋弧焊管焊缝的内部质量主要通过自动超声波探伤系统来检测.介绍了宝钢股份UOE生产线引进的管体焊缝自动超声波探伤设备及其焊缝跟踪原理.通过对该系统及超声波探伤样管结构等的分析,指出外焊缝形貌、内外焊缝宽度、内外焊缝中心偏移以及错边导致的焊缝形貌不规则等均会影响自动超声波探伤结果的准确性.最后,给出了提高埋弧焊管焊缝自动超声波探伤准确性的措施及方法.

  15. Welding.

    Science.gov (United States)

    Cowan, Earl; And Others

    The curriculum guide for welding instruction contains 16 units presented in six sections. Each unit is divided into the following areas, each of which is color coded: terminal objectives, specific objectives, suggested activities, and instructional materials; information sheet; transparency masters; assignment sheet; test; and test answers. The…

  16. Welding process

    International Nuclear Information System (INIS)

    This invention relates to a process for making a large number of weld beads as separate contours, spaced out from each other, by means of an automatic welding head. Under this invention, after striking the arc in the prescribed manner and positioning the torch on the first contour to be welded and having made the first weld bead, the torch current is reduced to bring about a part fade out of the arc. The torch is then moved to the starting position on a second contour to be welded where a static timed pre-fusion is effected by resumption of the welding current to carry out the second weld bead by following the second welding contour in the same manner and so forth. The invention particularly applies to the welding of tube ends to a tube plate

  17. Development of an automatic post-weld inspection system based on laser vision

    Institute of Scientific and Technical Information of China (English)

    Fu Xibin; Lin Sanbao; Fan Chenglei; Yang Chunli; Luo Lu

    2008-01-01

    In order to overcome the limitations of manual post-weld visual inspection approach, an automated inspection system is developed which uses three-dimensional laser vision system based on the principle of optical triangulation. The system hardware consists of a modular development kit (MDK), a computer, an actuating mechanism and so on. In image processing algorithms, extraction accuracy of centric line of laser stripe is the critical factor that determines the system performance. So according to the features of laser stripe image, a novel algorithm is developed to detect the central line of laser stripe fast and accurately. Experiments have demonstrated that this system can be used in various weld features inspection of both butt and fillet types of weld. Compared with traditional manual inspection method, this method has obvious dominance. The three-dimensional reconstruction result shows that this system has high accuracy and reliability.

  18. Ultrasound testing of the penetration of automatic welds of tubes on plates with using electron beams

    International Nuclear Information System (INIS)

    This control technique was developed within the scope of a D.G.R.S.T. study on electron beam welding of tubes to exchanger plates with a portable gun. The device developed is easy to use and enables the control to be carried out according to various techniques with good accuracy: used for acceptance tests merely for testing that a penetration to specification is reached and by working by 'hit and miss', it permits high work rates; used as a quality control system, it enables recordings to be made which accurately record the shape of the weld bead root, the penetration depth (and any possible weld compactness faults). The work rate is then reduced. Of course, the combined use of both techniques is possible, even advisable in some cases. For example, it is possible to imagine a total control by the first technique and an additional exploration by the second one. The exploration can then be to a percentage fixed by agreement or better, form a supplementary examination orientated according to the results obtained during the short examination

  19. The Model Building of CO2 Automatic Welding Process Parameters%CO2自动焊工艺参数模型建立

    Institute of Scientific and Technical Information of China (English)

    张立斌

    2015-01-01

    为准确方便地获得CO2自动焊工艺参数,利用正交设计及二次回归组合设计方法,对CO2自动焊接工艺参数之间的关系进行了优化试验,用SPSS软件对试验结果进行了统计分析与检验,并建立了CO2自动焊接工艺参数的数学模型.%In order to get the process parameters of CO2 automatic welding accurately and conveniently,this article conducts the optimization experiment to test the CO2 automatic welding process parameters using the orthogonal experimental design and quadratic regression combina-tion design.This paper also tests and analyzes the result with SPSS,and at the same time,the mathematical models of CO2 automatic weld-ing process parameters are established.

  20. Quality control for automatic submerged-arc welding on containment steel liner of Chashma Nuclear Power Plant project

    International Nuclear Information System (INIS)

    The paper introduces the basic constitution of containment steel liner to Pakistan Chashma nuclear power plant (C-2) project, and analyses the origin for the endless crack in the welding joints of SAW. To prevent occurring of endless cracks in SAW, well match of the main welding parameters is the base way to eliminate the weld of big reinforcement and small width. Correct chose and reuse of granular of welding flux is important for reducing of the blowhole and pit on weld surface. Secondary cutting can mitigate the deformation of the whole plate after welding. (author)

  1. Nuclear pipework - welding and inspection

    International Nuclear Information System (INIS)

    The subject is covered in sections: introduction emphasizing need for perfection in welding nuclear pipework; detailed procedures (British Standards, TIG welding, automatic orbital TIG welding machines); unacceptable faults; improving performance (higher quality of commercially-available grades of stainless steels); auto welding; testing 'nuclear' welding; safe working (standard specifications, radiography); training; radiographic techniques; radiographic procedures; other inspections. (U.K.)

  2. Remote automatic plasma arc-closure welding of a dry-storage canister for spent nuclear fuel and high-level radioactive waste

    International Nuclear Information System (INIS)

    A carbon steel storage canister has been designed for the dry encapsulation of spent nuclear fuel assemblies or of logs of vitrified high level radioactive waste. The canister design is in conformance with the requirements of the ASME Code, Section III, Division 1 for a Class 3 vessel. The canisters will be loaded and sealed as part of a completely remote process sequence to be performed in the hot bay of an experimental encapsulation facility at the Nevada Test Site. The final closure to be made is a full penetration butt weld between the canister body, a 12.75-in O.D. x 0.25-in wall pipe, and a mating semiellipsoidal closure lid. Due to a combination of design, application and facility constraints, the closure weld must be made in the 2G position (canister vertical). The plasma arc welding system is described, and the final welding procedure is described and discussed in detail. Several aspects and results of the procedure development activity, which are of both specific and general interest, are highlighted; these include: The critical welding torch features which must be exactly controlled to permit reproducible energy input to, and gas stream interaction with, the weld puddle. A comparison of results using automatic arc voltage control with those obtained using a mechanically fixed initial arc gap. The optimization of a keyhole initiation procedure. A comparison of results using an autogenous keyhole closure procedure with those obtained using a filler metal addition. The sensitivity of the welding process and procedure to variations in joint configuration and dimensions and to variations in base metal chemistry. Finally, the advantages and disadvantages of the plasma arc process for this application are summarized from the current viewpoint, and the applicability of this process to other similar applications is briefly indicated

  3. Welding method, and welding device for use therein, and method of analysis for evaluating welds

    OpenAIRE

    Aendenroomer, A.J.; Den Ouden, G.; Xiao, Y.H.; Brabander, W.A.J.

    1995-01-01

    Described is a method of automatically welding pipes, comprising welding with a pulsation welding current and monitoring, by means of a sensor, the variations occurring in the arc voltage caused by weld pool oscillations. The occurrence of voltage variations with only frequency components below 100 Hz indicates excessive welding through; the occurrence of voltage variations with only frequency components above 100 Hz indicates in sufficient welding through; a welding process showing proper we...

  4. Precise 3D Lug Pose Detection Sensor for Automatic Robot Welding Using a Structured-Light Vision System

    Directory of Open Access Journals (Sweden)

    Il Jae Lee

    2009-09-01

    Full Text Available In this study, we propose a precise 3D lug pose detection sensor for automatic robot welding of a lug to a huge steel plate used in shipbuilding, where the lug is a handle to carry the huge steel plate. The proposed sensor consists of a camera and four laser line diodes, and its design parameters are determined by analyzing its detectable range and resolution. For the lug pose acquisition, four laser lines are projected on both lug and plate, and the projected lines are detected by the camera. For robust detection of the projected lines against the illumination change, the vertical threshold, thinning, Hough transform and separated Hough transform algorithms are successively applied to the camera image. The lug pose acquisition is carried out by two stages: the top view alignment and the side view alignment. The top view alignment is to detect the coarse lug pose relatively far from the lug, and the side view alignment is to detect the fine lug pose close to the lug. After the top view alignment, the robot is controlled to move close to the side of the lug for the side view alignment. By this way, the precise 3D lug pose can be obtained. Finally, experiments with the sensor prototype are carried out to verify the feasibility and effectiveness of the proposed sensor.

  5. Automatic testing for weld of steel pipe; Kokan yosetsubu kensa no jidoka / inline ka

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, H. [Sumitomo Metal Industries Ltd., Osaka (Japan)

    1998-09-05

    Computer and artificial intelligence (AI) have used in the manufacturing process of steel pipes and process continuation and automation are carried out. Particularly, even the experienced technology of the site can be programmed in the control computer. With the continuation and automation of manufacturing process, most of the nondestructive tests are carried out in line or on the table and highly precise and speedy flow detection have been possible due to the general effect of performance upgrading of testing equipments and its surrounding technology (exchange of step for each size, setting of flow sensitivity) and so forth. Promotion of automation and in line process of nondestructive test is to achieve high precision and high efficiency like reduction of distribution of results by manual operation, reduction of testing time and so forth. As for the testing of weld of steel pipe of present company, the latest technology along with the continuation, automation, reduction of manpower have been considered in its testing device. Further, technological improvement by developing extremely small sensor, high efficiency and so forth is expected. 4 refs., 5 figs., 1 tab.

  6. WELDING METHOD

    Science.gov (United States)

    Cornell, A.A.; Dunbar, J.V.; Ruffner, J.H.

    1959-09-29

    A semi-automatic method is described for the weld joining of pipes and fittings which utilizes the inert gasshielded consumable electrode electric arc welding technique, comprising laying down the root pass at a first peripheral velocity and thereafter laying down the filler passes over the root pass necessary to complete the weld by revolving the pipes and fittings at a second peripheral velocity different from the first peripheral velocity, maintaining the welding head in a fixed position as to the specific direction of revolution, while the longitudinal axis of the welding head is disposed angularly in the direction of revolution at amounts between twenty minutas and about four degrees from the first position.

  7. Design and realization of a welding oscillator

    OpenAIRE

    Özcan, Muciz

    2014-01-01

    Welding is one of the most popular methods to combine metal pieces in manufacturing processes. Arc welding, among all welding techniques, is the most commonly used in manufacturing due to its cost and flexibility. During the manufacturing process, arc welding is either performed by an operator or by automatic tools such as welding oscillators. Using automatic tools has advantages over manual use, as the process will be faster, cheaper, and have less welding flaws. In this paper, a homem...

  8. Automatic orbital TIG-welding of small bore austenitic stainless steel tubes for nuclear fuel reprocessing plant

    International Nuclear Information System (INIS)

    Traditionally, manual welding techniques have been employed for shop and site fabrication of small bore austenitic stainless steel tubes in the nuclear fuel reprocessing plant of British Nuclear Fuels Limited (BNFL). This Paper describes an evaluation programme carried out to develop welding procedures for both 18Cr-13Ni-1Nb and 18Cr-10Ni low carbon stainless steel small bore tubing, the type of equipment used, and the modifications required for application to shop and site environments. (author)

  9. Improving automatic robotic welding in shipbuilding through the introduction of a corner-finding algorithm to help recognise shipbuilding parts

    OpenAIRE

    Sanders, David; Tewkesbury, Giles; Ndzi, David; Gegov, Alexander; Gremont, Boris; Little, Andrew

    2012-01-01

    A system that uses a combination of techniques to suggest weld requirements for ships’ parts is proposed. These suggestions are evaluated, decisions are made and then weld parameters are sent to a program generator. New image capture methods are being combined with a decision-making system that uses multiple parallel artificial intelligence (AI) techniques. A pattern recognition system recognises shipbuilding parts using shape contour information. Fourier descriptors provide information and n...

  10. Development of a test cellfor automatic assembly and tack welding of components for jet engine exhaust cases

    OpenAIRE

    Capellan, Alvaro; Tingelstad, Lars

    2011-01-01

    The assembly and tack welding of jet engine turbine exhaust cases (TEC) is a complex and time consuming operation currently performed manually at Volvo Aero Norway. The assembly tolerances are very tight with a maximum alignment offset of 0.7 mm. The company wants to investigate the possibility ofa complete or partial automation of this process.A test cell developed for studying the possibility of automating the assembly and tack welding operations of TEC components is presented. The test cel...

  11. Design of Automatic Welding Machine for Tube Plate Ring Weld of Tube Type Heat Exchanger and Welding Torch Orientation Simulation%管板式换热器管板环形焊缝自动焊机设计及焊枪定位仿真

    Institute of Scientific and Technical Information of China (English)

    徐向前; 周好斌; 王佳佳

    2015-01-01

    A simple, fast and precise positioning tube plate automatic welding machine was designed,according to the welding seam inaccurate positioning, low welding quality and efficiency in the tube plate seam welding of the tube plate exchanger during the welding process. The key of the welding machine is the localization and movement of the welding machine. The welding head is fixed on the gantry structure, and the stepping motor is used to drive the gantry structure and then the welding head's movement of two degrees of freedom is realized. The positioning of the welding head is realized by using CCD image processing. The design of the control system is completed based on C8051F020 MCU, and the human-computer interaction system includes the liquid crystal display and soft membrane 4 ×4 keyboard. Simulation by Matlab software, the center coordinates and radius of the pipe port circle can be obtained and welding head position can be achieved.%针对现有管板换热器管板环焊缝焊接过程中, 管板环焊缝定位不准确、 焊接质量和效率较低等问题, 设计了一种简单、 快捷、 定位精确的管板自动焊机. 焊接机头定位与移动是管板焊接的关键技术. 焊接机头固定在龙门架结构上, 采用步进电机驱动龙门架, 实现两自由度的运动; 利用CCD图像处理实现焊接机头的定位. C8051F020单片机作为主控芯片完成控制系统的设计, 液晶显示屏和4×4按键实现参数显示和设置. 通过Matlab软件仿真, 可获得钢管端口圆的半径和圆心坐标, 能够实现焊接机头定位.

  12. Vision-based detection of MAG weld pool

    Institute of Scientific and Technical Information of China (English)

    Gao Jinqiang; Wu Chuansong; Zhang Min; Zhao Yanhua

    2007-01-01

    Weld pool contains significant information about the welding process. The weld pool images of MAG welding are detected by LaserStrobe system. An algorithm for extracting weld pool edge is proposed according to the characteristics of MAG weld pool images. The maximum weld pool length and width are calculated. The measurement data can be used to verify the results of welding process simulation and to provide a good foundation for automatic control of MAG welding process.

  13. CRC全自动焊接工艺在中石化巴西管道建设中的应用%Application of CRC Automatic Welding Process in Brazil GASENE Pipeline of Sinopec Group

    Institute of Scientific and Technical Information of China (English)

    安龙虎; 冯志平; 李自力; 王太源

    2012-01-01

    In this article, it introduced automatic welding process, equipment composition and performance characteristics of America CRC pipeline which belongs to Sinopec Brazil GASENE project, compared and analyzed performance tests . The results indicated that all results of CRC pipeline automatic welding process can meet pipeline welding specification requirements of API 1104-1999 and Brazil N133 pipeline, and the welded joint performance is good . Meanwhile, this welding process possesses such advantages, such as high welding speed, high efficiency, high automation degree and good welding quality, and its application in Brazil pipeline project will provide great directive significance for popularizing automatic welding process in China .%介绍了中石化巴西GASENE管道项目中的美国CRC管道自动焊接工艺与设备的组成和性能特点,并通过性能试验结果的对比分析,发现CRC管道全自动焊接工艺各种试验结果均能满足API 1104-1999和巴油N133管道焊接规范要求,焊接接头性能优良.同时,该焊接工艺具有焊接速度快、效率高、自动化程度高以及焊接质量好等优点,其在巴西管道项目的应用对自动焊接工艺在国内的推广具有较好的指导意义.

  14. Development of automatic reactor vessel inspection systems: development of data acquisition and analysis system for the nuclear vessel weld

    Energy Technology Data Exchange (ETDEWEB)

    Park, C. H.; Lim, H. T.; Um, B. G. [Korea Advanced Institute of Science and Technology, Taejeon (Korea)

    2001-03-01

    The objective of this project is to develop an automated ultrasonic data acquisition and data analysis system to examine the reactor vessel weldsIn order to examine nuclear vessel welds including reactor pressure vessel(RPV), huge amount of ultrasonic data from 6 channels should be able to be on-line processed. In addition, ultrasonic transducer scanning device should be remotely controlled, because working place is high radiation area. This kind of an automated ultrasonic testing equipment has not been developed domestically yet In order to develop an automated ultrasonic testing system, RPV ultrasonic testing equipments developed in foreign countries were investigated and the capability of high speed ultrasonic signal processing hardwares was analyzed in this study, ultrasonic signal processing system was designed. And also, ultrasonic data acquisition and analysis software was developed. 11 refs., 6 figs., 9 tabs. (Author)

  15. Welding technologies for nuclear machinery and equipment

    International Nuclear Information System (INIS)

    The main welding methods applied to nuclear machinery and equipment are shielded metal arc welding, submerged arc welding, MAG welding and TIG welding. But in the last 10 years, in order to improve the reliability required for the welding of nuclear machinery and equipment, the welding technologies aiming at the reduction of heat input, the decrease of the number of welding pass and the automatic control of welding factors have been applied for the main purpose of bettering the quality and excluding human errors. The merits and the technology of narrow gap, pulsed MAG welding and melt-through welding are explained. As the automation of TIG welding, image processing type narrow gap, hot wire TIG welding and remote control type automatic TIG welding are described. For the longitudinal welding of active metal sheet products, plasma key-hole welding is applied. Since the concentration of its arc is good, high speed welding with low heat input can be done. For the stainless steel cladding by welding, electroslag welding has become to be employed in place of conventional submerged arc welding. Arc is not generated in the electroslag welding, and the penetration into base metal is small. (K.I.)

  16. Television system for automatic control of electrode position during argon arc welding of large-sized components

    International Nuclear Information System (INIS)

    The article deals with a TV system designed for controlling the position of electrode during argon-arc welding of butt joints with deep bevelling (levelling depth exceeds 10 mm). The operation of the system is based on the processing of bevelling images. The application of the system ensures the travel of the electrode along bevelling axis with an accuracy ±1 mm, minimum. 2 refs., 3 figs

  17. Development of automatic reactor vessel inspection systems; development of data acquisition and analysis system for the nuclear vessel weld

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Po; Park, C. H.; Kim, H. T.; Noh, H. C.; Lee, J. M.; Kim, C. K.; Um, B. G. [Research Institute of KAITEC, Seoul (Korea)

    2002-03-01

    The objective of this project is to develop an automated ultrasonic data acquisition and data analysis system to examine heavy vessel welds. In order to examine nuclear vessel welds including reactor pressure vessel(RPV), huge amount of ultrasonic data from 6 channels should be able to be on-line processed. In addition, ultrasonic transducer scanning device should be remotely controlled, because working place is high radiation area. This kind of an automated ultrasonic testing equipment has not been developed domestically yet. In order to develop an automated ultrasonic testing system, RPV ultrasonic testing equipments developed in foreign countries were investigated and the capability of high speed ultrasonic signal processing hardwares was analyzed. In this study, ultrasonic signal processing system was designed. And also, ultrasonic data acquisition software was developed. The new systems were tested on the RPV welds of Ulchin Unit 6 to confirm their functions and capabilities. They worked very well as designed and the tests were successfully completed. 13 refs., 34 figs., 11 tabs. (Author)

  18. Automatic welding procedure of heater for pressurizer in nuclear power%核岛主设备稳压器加热器全自动焊接工艺

    Institute of Scientific and Technical Information of China (English)

    廖国平

    2011-01-01

    针对核岛主设备稳压器加热器焊接接头特殊的接头形式和焊接要求,采用全自动氩+氦弧焊进行超低碳奥氏体不锈钢薄壁小管对接焊接工艺.为确保焊缝质量和熔透性,针对特殊的焊缝结构形式,进行了反复的工艺试验.结果表明:接头结构、焊接材料、焊接设备、保护气体、焊接程序、装配质量和钨极质量都直接影响最后的焊接质量和焊缝反面熔透性.摸索出了一套完整的焊接工艺,顺利完成了加热器焊缝的焊接.%In this paper,use automatic welding of super low carbon austenitic stainless steel thin wall tube with Ar+He shield gas in case of especial welds type of heater for pressurizer in nuclear power and welding requirements,for satifying welding quality and back penetrate ,procedure test and test result show that joint type,welding material ,welding equipment ,protective gas ,welding program, assemble quality and tungsten quality shall affect final welding quality and back penetrate. After tackling key problem,we finish welding of the key nuclear products without foreign technical support.

  19. A new welding technique for stainless steel pipe butt welds

    International Nuclear Information System (INIS)

    A modified TIG welding process which uses an accurately machined consumable weld socket ring for aligning pipes and providing filler material has been developed by British Nuclear Fuels and used successfully at Windscale Site Construction. The technique and its practical application at Windscale for automatic orbital TIG welding of stainless steel pipe is described. (author)

  20. Welding in hostile environment for nuclear and offshore industry

    International Nuclear Information System (INIS)

    The paper reviews recent developments of duplex stainless steel and clad pipe welding and under water welding for offshore structures and for reactor fuel storage pool and remote automatic dry welding

  1. Robots and integrated welding centers for the continuous self-adaptive welding of large parts

    International Nuclear Information System (INIS)

    The report shows that self-adaptive welding systems are well suited for automatic welding of large components. Some new self-adaptive guiding, systems, automatic manipulators and integrated welding centres developed by the author are described. The new production system, which is based on multiple and variable control of kinematic conditions, welding parameters and quality control, will make it possible to have high productivity, good welding quality, and easy adaptability together with simple programming and protection of the environment. (orig.)

  2. Automatic inspection of oil and gas pipe welded joints by radiographic images analyses; Analise automatica de imagens radiologicas aplicada a inspecao de juntas soldadas em tubulacoes de oleo e gas

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Guilherme A.; Felisberto, Marcelo K.; Pilkel, Lucas V.; Centeno, Tania M.; Arruda, Lucia V.R. [Centro Federal de Educacao Tecnologica do Parana (CEFET-PR), Curitiba, PR (Brazil). Curso de Pos-graduacao em Engenharia Eletrica e Informatica (CPGEI). Lab. de Automacao e Sistemas de Controle Avancado

    2004-07-01

    The reliability and integrity evaluation of structures and equipment on the petroleum and gas industry is an absolute necessary care due to economic reasons and safety. As a consequence, new supporting technologies for well known nondestructive test and evaluation methods have been developed in order to automate these inspection processes, improving their robustness, accuracy and quickness. On this way, the present work introduces solutions to overcome some obstacles to the automation of the radiographic image analysis task for the pipeline weld joint inspection, on radiographic non-destructive tests and evaluations. The main contributions are related to the improvements to techniques for the automatic weld bean segmentation and the development of an effective algorithm for the weld bean defect detection and extraction of relevant defect descriptors. (author)

  3. Online Visual Quality Inspection for Weld Seams

    Science.gov (United States)

    Löhndorf, Maike; Ramoser, Herbert; Cambrini, Luigi

    2007-12-01

    Arc welding is a widely used technology in almost all sectors of industrial production. Many tasks are automatically performed by robots. This paper presents a flexible vision based quality management system to detect defects online during the weld process.

  4. Study on the Automatic Welding Process Experiment of X80 Pipeline Steel Self-shielded Flux-cored Wires%X80管线钢自保护药芯焊丝自动焊工艺试验研究

    Institute of Scientific and Technical Information of China (English)

    王长江; 曾惠林; 杨雪梅; 蒋戎; 刘然

    2014-01-01

    Aiming at the X80 high strength pipeline steel and related welding technical specification requirements,it adopted independent development eight welding torch internal welder and self-shielded flux-cored wire automatic welder to carry out pipeline all-position welding test,and conducted mechanical properties testing of welded joints. It determined reasonable groove type,welding wire type and matching welding parameters,and formulated welding technology internal welding machine for root welding+self-shielded flux-cored wire automatic welding for fill and cover welding. The test results proved that the welding process is reasonable,simple operation,and high efficiency,the various performance indicators of welded joints all meet the X80 steel grade pipeline engineering welding specification and relevant national standards.%针对X80高强管线钢及相关焊接技术规范要求,应用自主研发的八焊炬内焊机及自保护药芯焊丝自动焊机进行管道全位置焊接试验,并进行焊接接头力学性能测试。确定了合理的坡口形式、焊丝型号及与之匹配的焊接参数,制定了“内焊机根焊+管道自保护药芯焊丝自动焊填充、盖面焊”的焊接工艺。试验结果证明,焊接工艺制定合理,操作简单,效率高,其焊接接头的各项性能指标均满足X80钢级管道工程焊接规范及国家相关标准要求。

  5. 光纤预制棒接管的自动控制研究%The research of automatic control optical fiber preform welding

    Institute of Scientific and Technical Information of China (English)

    邵金涛; 王新箭; 满小忠; 沈国锋; 程遥

    2013-01-01

    According to the equipment modification project, briefly introduced the automatic control system's realization method of the optical fiber preform welding process. The system uses Mitsubishi PLC and touch panel to replace the existing manual operation mode. Meanwhile the system's speed control temperature control will be greatly improved. In addition the system also added the CCD temperature testing device, to provide a more reliable judgment for the system. The actual production conditions show that the control system improves the product quality and greatly reduce the labor intensity.%根据设备改造项目实例,简要介绍了光纤预制棒接管自动控制系统的实现方法.该系统采用三菱PLC和威纶通触摸屏代替原有的手动操作模式,提高了系统中速度控制和温度控制的精确性和稳定性.同时系统增加了CCD温度检测,为程序控制提供了更加可靠的判断条件.实际生产表明:该控制系统提高了光棒预处理的产品质量,大大减轻了劳动强度.

  6. Method of welding nuclear reactor fuel assemblies

    International Nuclear Information System (INIS)

    Disclosed is a method of welding tabs projecting outwardly from grip straps in a fuel assembly grid to a control rod guide thimble positioned in a cell in the grid including providing a weld guide having openings therein which receive dimples on the strap when the weld guide is placed in a cell adjacent to the cell containing the control rod guide thimble. The weld guide includes an opening which falls into alignment with a tab so that when a welding gun electrode is placed through the opening and into contact with a tab, the other electrode is automatically centered on its tab thus permitting accurate spot welding of the parts. To make a second spot weld on the same tab but at a point outwardly from the first spot weld, a second weld guide having an opening therein displaced a greater distance from a reference point on the weld guide, is placed in the same cell and the welding process repeated

  7. Customized orbital welding meets the challenge of titanium welding

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    Titanium has emerged as the material of choice for tubing used in surface condensers around the world in both new and retrofit configurations. A major worldwide supplier of steam surface condensers to the electric utility industry, Senior Engineering is finding an increased use of titanium tubes and tube sheets in condenser specifications. When compared to other alloys, titanium`s light weight is efficient in design, handling, transportation and installation activities. Additionally, it maintains a stable price structure. Senior Engineering implements an orbital welding process using fusion gas tungsten arc welding (GTAW) for its titanium tube-to-tube sheet welding. Orbital welding involves the use of a welding apparatus placed inside a tube or pipe to automatically and precisely weld a 360-deg joint. When welding manually, a welder stops several times during the weld due to the large amount of time and fatigue involved in achieving 360-deg welds, which results in lack of fusion. An automated orbital welding system, however, can accomplish the task as one continuous weld. This reduces process time and decreases lack of fusion. The orbital welding systems, featuring a microprocessor-based controller, an inverter-based power supply, an expandable mandrel and a customized torch shroud, reduced welding labor by 35%. The improved labor efficiency justified the addition of two more of the systems in January 1996.

  8. Customized orbital welding meets the challenge of titanium welding

    International Nuclear Information System (INIS)

    Titanium has emerged as the material of choice for tubing used in surface condensers around the world in both new and retrofit configurations. A major worldwide supplier of steam surface condensers to the electric utility industry, Senior Engineering is finding an increased use of titanium tubes and tube sheets in condenser specifications. When compared to other alloys, titanium's light weight is efficient in design, handling, transportation and installation activities. Additionally, it maintains a stable price structure. Senior Engineering implements an orbital welding process using fusion gas tungsten arc welding (GTAW) for its titanium tube-to-tube sheet welding. Orbital welding involves the use of a welding apparatus placed inside a tube or pipe to automatically and precisely weld a 360-deg joint. When welding manually, a welder stops several times during the weld due to the large amount of time and fatigue involved in achieving 360-deg welds, which results in lack of fusion. An automated orbital welding system, however, can accomplish the task as one continuous weld. This reduces process time and decreases lack of fusion. The orbital welding systems, featuring a microprocessor-based controller, an inverter-based power supply, an expandable mandrel and a customized torch shroud, reduced welding labor by 35%. The improved labor efficiency justified the addition of two more of the systems in January 1996

  9. 钢管焊缝超声自动检测系统能力的鉴定%Identification for the Ability of Steel Pipe Weld Automatic Ultrasonic Testing System

    Institute of Scientific and Technical Information of China (English)

    甘正红; 方晓东; 余洋; 苏继权

    2013-01-01

    In this article, it introduced the main contents to be detected in multichannel steel pipe weld automatic ultrasonic testing system, calibration method to detecting system(equipment), and service conditions of detecting system . Combined with steel pipe weld automatic ultrasonic testing requirements specified in API SPEC 5L/IS0 3183 standard, it discussed the main properties and identification method of multichannel steel pipe weld automatic ultrasonic testing system, provided specific requirements for linearity, horizontal linearity, dynamic range, comprehensive property and others. The feasibility of identification ability was proved through actual application.%介绍了多通道钢管焊缝超声波自动检测系统待检测的主要内容、对检测系统(设备)进行校准的方法以及检测系统的使用条件.结合API SPEC 5L/ISO 3183标准对钢管焊缝超声自动检测的要求,探讨了多通道钢管焊缝超声波自动检测系统的主要性能指标及鉴定方法,给出了主要性能指标如直线性和水平线性、动态范围、综合性能等的具体要求.并通过实际应用表明了鉴定能力的可行性.

  10. AECL devises new nuclear welding system

    International Nuclear Information System (INIS)

    Automatic autogenous TIG pipe butt welding equipment has been developed for producing joints in reactor coolant monitoring systems for tubes of between 6 and 25 mm diameter and up to 3 mm wall thickness in stainless steel. The equipment is designed to work on site with power requirements of up to 2.2 KW maximum. A major feature of the design, therefore, was a welding system of sufficiently small size, portability and ruggedness to be able to withstand on-site conditions. Quality control is carried out automatically by a comparison of welding parameters with those of a standard acceptable weld. Details of power source characteristics and welding procedure are given. (author)

  11. Study on the control system of automatic welding system based on ARM%基于ARM的机器人自动焊接控制系统

    Institute of Scientific and Technical Information of China (English)

    段锦程; 石永华; 俞国庆; 梁斌

    2011-01-01

    Welding distortion emerges in three-dimensional seam welding.The teaching-playback robot can not correct the deviation real-timely by itself.Therefore,it is necessary to correct the deviation during welding process real-timely.Based on ARM9-S3C2440,by using RS-232 to communicate with welding robot,this control system can adjust the welding traveling path in real-time.lt can control the position of the welding torch to get rid of the side effect of hot deformation.Using this control system, it is guaranteed that not only the welding torch moves along the seam center,but also that the contact tube to workpiece distance(CTWD) is equal.In welding experiments, it produces good welding quality.%立体曲线焊缝焊接时会产生较大的焊接变形,如以示教方式进行机器人焊接将导致焊接路径的偏离,必须在焊接过程中进行实时纠偏.设计开发了一种焊接机器人控制系统,硬件以ARM9-S3C2440为核心,通过RS232与机器人进行通信,编写了控制软件,实现了焊接机器人的焊枪位置实时调整,有效应对了焊接热变形的影响.既保证了焊枪沿着坡口中心运动,又保证了导电嘴到工件的距离(CTWD),焊接工艺稳定,焊缝质量较好.

  12. Welding with the TIG automatic process of the end fittings for the execution of the Embalse nuclear power plant fuel channel rechange

    International Nuclear Information System (INIS)

    The present work describes the methodology for the cutting of the existing welding and subsequent welding applied by the TIG process of the coupling composed by the shroud ring and the end fitting ring from one of Embalse nuclear power plant's fuel channels. The replacement will be previously determined by the SLAR-ETTE mechanism where a displacement operated among the Gartner Spring rings, the pressure tubes are separated from the Calandria tubes. The welding to be carried out has the function of stamping the CO2 annular gas (thermal insulator) circulating between the pressure tube and the Calandria one during the functioning of the plant. (Author)

  13. The Effect of Welding Current and Composition of Stainless steel on the Panetration in GTAW

    OpenAIRE

    Ramazan Yılmaz; Turgay Tehçi

    2012-01-01

    In this study, welding was performed on the plates of two different types of AISI 316 and AISI 316Ti austenitic stainless steels by GTAW (Gas Tungsten Arc Welding) without using welding consumable in flat position. Automatic GTAW welding machine was used to control and obtain the exact values. The effects of welding currents used in welding process and the compositions of the stainless steels materials on the penetration were investigated. Weld bead size and shape such as bead width and dept ...

  14. Hyperbaric welding of duplex stainless steel pipelines offshore.

    OpenAIRE

    Farrell, J.

    1996-01-01

    Three duplex stainless steels (Avesta 2205, Sandvik SAF2507 and Zeron 100) were successfully welded automatically at a range of pressures from 1 to 32bar. The gas tungsten arc (GTA) welding process was chosen as it allows a high degree of control to be exercised during welding. Initial autogenous bead on plate welds established the effects of pressure on the welding process and allowed the process parameters to be determined for subsequent experiments. Analysis of the eff...

  15. Nondestructive testing of weldings

    International Nuclear Information System (INIS)

    Today the nondestructive testing of materials with transverse weldings would be often neglect. Because the production of this parts will get more expensive it is interesting to test the parts eg. cans with ultrasound. Within this research program we developed a testing device for automatically testing of materials with transverse weldings, e.g. tubes. Functional characteristics: after putting in the test tube in the testing device the transducer is adjusted automatically to the best adjustment. This takes place with three step motors. The mechanic of adjustments gets its information from an optimal computer. The optimal computer processes the signals, which it gets from the automatic evaluator during the adjustment and stores the optimal adjustment parameters. With an additional equipment on can identify the exact source of error, if the testing device turns out and the repairing of the part can take place very fast. With an appropiate mechanical science the devide is useable in a production line with high flow rate. (orig.)

  16. ALGORITHM AND IMPLEMENTATION OF AUTO-SEARCHING WELD LINE FOR WELDING MOBILE ROBOT

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ke; L(U) Xueqin; WU Yixiong; LOU Songnian

    2006-01-01

    An algorithm of auto-searching weld line for welding mobile robot is presented.Auto-searching weld line is that the robot can automatically recognize a weld groove according to the characteristics of the weld groove before welding, and then adjust itself posture to the desired status preparing for welding, namely, it is a process that the robot autonomously aligns itself to the center of welding seam. Firstly, the configuration of welding mobile robot with the function of auto-searching weld line is introduced, then the algorithm and implementation of auto-searching weld line are presented on the basis of kinematics model of the robot, at last trajectory planning among auto-searching weld line is investigated in detail. The experiment result shows that the developed welding mobile robot can successfully implement the task of auto-searching weld line before welding, tracking error precision can be controlled to approximate ± 1.5 mm, and satisfy the requirement of practical welding project.

  17. Residual solidification stress in plug welds

    International Nuclear Information System (INIS)

    Installation of the plugs in Steam Generators and Heat Exchangers is performed using GTAW process with filler metal. During the cooling phase of the weld puddle residual stresses will be generated in the weld. The residual stresses together with the stresses from the primary and secondary loads will define the total stress in the weld. The level of total stress is important for the reliability of the plug joints. Typically, the welding procedures prescribe a range of values for each welding parameters, therefore the welder has the option to select a relative wide range of combinations of parameters based on test results, welding position, experience, etc. Manual welding processes are more susceptible to larger variation of the heat input than the automatic welding processes. The combination of the welding parameters may be controlled by a generic parameter called welding heat input. The net effect of the heat input is to control the energy introduced by an arc at weld joint such that adequate weld puddle is produced. The heat input along with the thermal properties of the materials control the temperature distribution in the welded joint. Ultimately, the response of the structure to the thermal loads resulted from the non-uniform distribution of temperature is a non-uniform distribution of the plastic strains that results in residual stresses. This paper presents the effect of variation of welding heat input on distribution of residual stresses. Finite element method is used to simulate the welding process for various heat inputs that may be encountered during plug welding. The analysis is performed in two steps. In the first step a thermal transient analysis is performed in which the temperature distribution due to a moving heat source is obtained. The resulting thermal field is used as input data for structural analysis. It is shown that the extent of residual stresses in the weld joint is affected by the energy used to produce the weld and can be related to the

  18. Welding Curriculum.

    Science.gov (United States)

    Alaska State Dept. of Education, Juneau. Div. of Adult and Vocational Education.

    This competency-based curriculum guide is a handbook for the development of welding trade programs. Based on a survey of Alaskan welding employers, it includes all competencies a student should acquire in such a welding program. The handbook stresses the importance of understanding the principles associated with the various elements of welding.…

  19. Welding IV.

    Science.gov (United States)

    Allegheny County Community Coll., Pittsburgh, PA.

    Instructional objectives and performance requirements are outlined in this course guide for Welding IV, a competency-based course in advanced arc welding offered at the Community College of Allegheny County to provide students with proficiency in: (1) single vee groove welding using code specifications established by the American Welding Society…

  20. Study on visual image information detection of external angle weld based on arc welding robot

    Science.gov (United States)

    Liu, Xiaorui; Liu, Nansheng; Sheng, Wei; Hu, Xian; Ai, Xiaopu; Wei, Yiqing

    2009-11-01

    Nowadays, the chief development trend in modern welding technology is welding automation and welding intelligence. External angle weld has a certain proportion in mechanical manufacture industries. In the real-time welding process, due to hot deformation and the fixture of workpieces used frequently, torch will detach welding orbit causes deviation, which will affect welding quality. Therefore, elimination weld deviation is the key to the weld automatic tracking system. In this paper, the authors use the self-developed structured light vision sensor system which has significant advantage compared with arc sensors to capture real-time weld images. In the project of VC++6.0 real-time weld image processing, after binaryzation with threshold value seventy, 3*1 median filter, thinning, obtain weld main stripe. Then, using the extraction algorithm this paper proposed to obtain weld feature points, and compute position of weld. Experiment result verified that the extraction algorithm can locate feature points rapidly and compute the weld deviation accurately.

  1. 换热器管板角焊缝相控阵自动超声检测技术研究%Research on Phased Array Automatically Ultrasonic Testing Technique of Tube to Tube-sheet Welds in Heat Exchanger

    Institute of Scientific and Technical Information of China (English)

    郭伟灿; 钱盛杰; 凌张伟

    2015-01-01

    在换热器的制作过程中,换热管与管板常采用焊接形式,焊缝的质量是保证换热器长期正常运行的关键。常规的超声检测方法具有系统复杂、检测效率低等缺点。因此,提出了相控阵超声检测技术,并开发了相控阵超声检测系统,以实现对管板角焊缝的自动超声检测。系统由周向步进电机实现周向扫查,纵向扫查采用相控阵探头电子线扫查,从而实现超声 C 扫描检测。通过带有气孔、未熔合等典型缺陷对检测系统进行试验研究。结果表明,该技术可以有效地检测出换热器管板角焊缝中的典型缺陷。%In the process of produce heat exchangers,heat exchanger′s tube and tube sheet conjunction adopt the form of welding,the quality of welding is the key insurance for the long and normal operation of the heat exchangers.The conventional ultrasonic testing method has many disadvantages like complicated system and low efficiency of detection.Thus,it puts forward the phased array ultrasonic testing technique and develops the ultrasonic testing system to accomplish the automatically ultrasonic testing of the tube to tube-sheet welds.The ultrasonic C-scan was carried out by the ultrasonic testing system with its circumfer-ential scanning by a mechanical scanning device while the axial electronic linear scanning by the phased array probe.At last,the tests on samples with typical flaws such as porosity flaws and the incomplete fu-sion flaws were performed by the ultrasonic testing system.Experiment results showed that the phased ar-ray ultrasonic technique could effectively detect the typical flaws in the tube to tube-sheet welds of heat exchanger.

  2. Neural network modeling for weld shape process of P-GMAW

    Institute of Scientific and Technical Information of China (English)

    Yan Zhihong; Wu Lin; Zhang Guangjun; Gao Hongming

    2007-01-01

    Weld shape control is a fundamental issue in automatic welding. In this paper, a double side visual system is established for pulsed gas metal arc welding (P-GMAW), and both topside and backside weld pool images can be captured and stored continuously in real time. By analyzing the weld shape regulation with the molten metal volume, some topside weld pool characterized parameters (WPCPs) are proposed for determining penetration in butt welding of thin mild steel. Moreover, some BP network models are established to predict backside weld pool width with welding parameters and WPCPs as inputs.

  3. Development of seal welding repair technology for CRD stub-tube

    International Nuclear Information System (INIS)

    Seal welding is a repair method when crack by Stress Corrosion Cracking (SCC) is found in weld portion of core internals including pressure boundary component in nuclear power plant. Seal welding is welded directly on surface of existing SCC crack and prevents SCC propagation by isolating SCC crack from reactor water environment. In this study, development of seal welding technology using automatic TIG Welding was executed, and the applicability of seal welding method to CRD stub-tube weld portion was confirmed by examination of full scale weld test and analysis. (author)

  4. Automated Fuel Element Closure Welding System

    International Nuclear Information System (INIS)

    The Automated Fuel Element Closure Welding System is a robotic device that will load and weld top end plugs onto nuclear fuel elements in a highly radioactive and inert gas environment. The system was developed at Argonne National Laboratory-West as part of the Fuel Cycle Demonstration. The welding system performs four main functions, it (1) injects a small amount of a xenon/krypton gas mixture into specific fuel elements, and (2) loads tiny end plugs into the tops of fuel element jackets, and (3) welds the end plugs to the element jackets, and (4) performs a dimensional inspection of the pre- and post-welded fuel elements. The system components are modular to facilitate remote replacement of failed parts. The entire system can be operated remotely in manual, semi-automatic, or fully automatic modes using a computer control system. The welding system is currently undergoing software testing and functional checkout

  5. Microcomputer Checks Butt-Weld Accuracy

    Science.gov (United States)

    Clisham, W.; Garner, W.; Cohen, C.; Beal, J.; Polen, R.; Lloyd, J.

    1982-01-01

    Electrical gage and microcomputer eliminate time-consuming manual measurements. Alinement and angle of plates on either side of butt weld are measured and recorded automatically by hand-held gage and desk-top microcomputer. Gage/micro-computer quickly determine whether weld is within dimensional tolerances or whether reworking is needed. Microcomputer prints out measurements while operator moves gage from point to point along weld. Out-of-tolerance measurements are marked by an asterisk on printout.

  6. Advanced Welding Concepts

    Science.gov (United States)

    Ding, Robert J.

    2010-01-01

    Four advanced welding techniques and their use in NASA are briefly reviewed in this poster presentation. The welding techniques reviewed are: Solid State Welding, Friction Stir Welding (FSW), Thermal Stir Welding (TSW) and Ultrasonic Stir Welding.

  7. Seam-Tracking for Friction Stir Welded Lap Joints

    Science.gov (United States)

    Fleming, Paul A.; Hendricks, Christopher E.; Cook, George E.; Wilkes, D. M.; Strauss, Alvin M.; Lammlein, David H.

    2010-11-01

    This article presents a method for automatic seam-tracking in friction stir welding (FSW) of lap joints. In this method, tracking is accomplished by weaving the FSW tool back-and-forth perpendicular to the direction of travel during welding and monitoring force and torque signals. Research demonstrates the ability of this method to automatically track weld seam positions. Additionally, tensile and S-bend test result comparisons demonstrate that weaving most likely does not reduce weld quality. Finally, benefits of this weave-based method to FSW of lap joints are discussed and methods for incorporating it into existing friction stir welding control algorithms (such as axial load control) are examined.

  8. Steel welding.

    OpenAIRE

    Kučera, Marek

    2011-01-01

    Topic of the thesis concerns the problem of steel welding. The aim was to give acomprehensive overview on the topic, describe the known methods, advantages and disadvantages of welding technology. The introductory part is focused on introducing the basics of the process required to produce high-quality connections. Chapter three offers an overview of known and used welding methods with thein brief description of the method. The next chapter describes steel as material suitable for welding....

  9. Welding Technician

    Science.gov (United States)

    Smith, Ken

    2009-01-01

    About 95% of all manufactured goods in this country are welded or joined in some way. These welded products range in nature from bicycle handlebars and skyscrapers to bridges and race cars. The author discusses what students need to know about careers for welding technicians--wages, responsibilities, skills needed, career advancement…

  10. High quality, high efficiency welding technology for nuclear power plants

    International Nuclear Information System (INIS)

    For nuclear power plants, it is required to ensure the safety under the high reliability and to attain the high rate of operation. In the manufacture and installation of the machinery and equipment, the welding techniques which become the basis exert large influence to them. For the purpose of improving joint performance and excluding human errors, welding heat input and the number of passes have been reduced, the automation of welding has been advanced, and at present, narrow gap arc welding and high energy density welding such as electron beam welding and laser welding have been put to practical use. Also in the welding of pipings, automatic gas metal arc welding is employed. As for the welding of main machinery and equipment, there are the welding of the joints that constitute pressure boundaries, the build-up welding on the internal surfaces of pressure vessels for separating primary water from them, and the sealing welding of heating tubes and tube plates in steam generators. These weldings are explained. The welding of pipings and the state of development and application of new welding methods are reported. (K.I.)

  11. Software Design and Application of Ultrasonic Automatic Flaw Detection System of Welded Steel Pipes%焊接钢管超声波自动探伤系统中的软件设计与应用

    Institute of Scientific and Technical Information of China (English)

    常少文

    2011-01-01

    The software design of pipe ultrasonic automatic flaw detection system, and its application on welded steel pipes production were introduced. It combined traditional ultrasonic inspection technology with some advanced technologies, such as industrial control computer, virtual instrument, intelligent flaw detection, etc. With the careful programming flaw detection operation, it could evaluate correctly and select strictly for complex flaw echo, its error in alarm could be effectively avoided. The review of flaw echo waveform overcame insufficiency of flaw category identification in ultrasonic automatic inspection, and achieved misinformation rate being smaller than 2%, and fail to report rate being zero.%分析了焊接钢管超声波自动探伤系统的软件设计以及在焊接钢管检测中的应用状况.把传统的超声波检测技术和先进的工业控制计算机、虚拟仪器和智能化探伤等技术相结合,配合精心编制的探伤操作程序,可做到对复杂缺陷回波的准确评价和严格筛选,有效地避免了系统的误报警.缺陷波形回放功能克服了超声波自动探伤中的缺陷种类难以识别的不足,并做到误报率<2%,漏报率为0.

  12. Resistance welding

    DEFF Research Database (Denmark)

    Bay, Niels; Zhang, Wenqi; Rasmussen, Mogens H.;

    2003-01-01

    Resistance welding comprises not only the well known spot welding process but also more complex projection welding operations, where excessive plastic deformation of the weld point may occur. This enables the production of complex geometries and material combinations, which are often not possible...... to weld by traditional spot welding operations. Such joining processes are, however, not simple to develop due to the large number of parameters involved. Development has traditionally been carried out by large experimental investigations, but the development of a numerical programme system has...... changed this enabling prediction of the welding performance in details. The paper describes the programme in short and gives examples on industrial applications. Finally investigations of causes for failure in a complex industrial joint of two dissimilar metals are carried out combining numerical...

  13. 核电工程主管道窄间隙自动焊 RT 层间疑似缺陷的处理%Treatment to the RT Suspected Layer Defects in Narrow Gap Automatic Welding on Nuclear Power Engineering

    Institute of Scientific and Technical Information of China (English)

    马新朝

    2015-01-01

    Taking the 2# unit 1U4, 1U6 main pipe welding joint with suspected interlayer incomplete fusion defects in FangjiaShan nuclear power project as an example, this paper analyzes the narrow-gap automatic welding characteristics of main pipe, puts forward measures to avoid weld defects. The paper also analyzes the RT characteristics of nuclear power main pipe with thick casting austenitic stainless steel. Using the method of weld center transillumination and migration of weld center twice transillumination, can effectively avoid undetected defects. Also, the UT process is a good practice of welding quality inspection and flaw location, and could be widely applied on the welding test of thick walled tube.%文章以方家山核电工程2#机组1U4、1U6主管道焊口在焊接过程中出现的疑似层间未熔合缺陷为例,分析了核电工程主管道窄间隙自动焊的焊接特点,提出了如何避免出现焊接缺陷的措施;分析了核电主管道厚壁铸造奥氏体不锈钢的RT特点,采用焊缝中心透照及偏移焊缝中心两次透照的方法,可以有效避免漏检缺陷,同时,采取UT工艺是检验焊接质量和缺陷定位的良好实践,可以广泛应用于厚壁管的焊接检验。

  14. Welding process automation in power machine building

    International Nuclear Information System (INIS)

    The level of welding automation operations in power engineering and ways of its enhancement are highlighted. Used as the examples of comlex automation are an apparatus for the horizontal welding of turbine rotors, remotely controlled automatic machine for welding ring joint of large-sized vessels, equipment for the electron-beam welding of steam turbine assemblies of alloyed steels. The prospects of industrial robots are noted. The importance of the complex automation of technological process, including stocking, assemblying, transportation and auxiliary operations, is emphasized

  15. Flaw Determination and Evaluation of Ultrasonic Automatic Flaw Detection System for Welded Steel Pipes%焊接钢管超声波自动探伤中的缺陷相关评判方法

    Institute of Scientific and Technical Information of China (English)

    常少文; 吕育栋; 曹华勇; 田岩平; 刘常庆; 韩玉朝; 孙志敏

    2012-01-01

    分析了焊接钢管超声波自动探伤检测中的缺陷相关评判方法,配合编制的时间相关、位置相关、行为相关、特征相关、性质相关的5种相关法判伤软件程序,使自动化探伤系统具有了智能评判功能,可做到对复杂缺陷回波的准确评价和严格筛选,有效地避免了系统的误报警,可满足连续自动化探伤要求,并做到误报率〈2%,漏报率为0。%The flaw determination and evalution methods of ultrasonic automatic flaw detection examining on welded steel pipes are introduced. With the careful programming of time correlation, location correlation, behavior correlation, features correlation, and nature correlation together with related software program, the testing system thus has a smart judgment function to evaluate correctly and select strictly for complex flaw echo, and its error in alarm can be effectively avoided. So designed system was able to meet the continuous automation testing requirements and achieve misinformation rate smaller 2% and fail to report rate to 0.

  16. System for the automatic analysis of defects in X-ray imaging

    International Nuclear Information System (INIS)

    A radiological device was developed to obtain direct digitized views. A set of algorithms has been developed and demonstrated for the automatic evaluation of weldings. Some results concerning electronuclear fuel pin weldings are presented

  17. Optimal parameters determination of the orbital weld technique using microstructural and chemical properties of welded joint

    International Nuclear Information System (INIS)

    The paper deals with the study of the main parameters of thermal cycle in Orbital Automatic Weld, as a particular process of the GTAW Weld technique. Also is concerned with the investigation of microstructural and mechanical properties of welded joints made with Orbital Technique in SA 210 Steel, a particular alloy widely use during the construction of Economizers of Power Plants. A number of PC software were used in this sense in order to anticipate the main mechanical and structural characteristics of Weld metal and the Heat Affected Zone (HAZ). The papers also might be of great value during selection of optimal Weld parameters to produce sound and high quality Welds during the construction / assembling of structural components in high requirements industrial sectors and also to make a reliable prediction of weld properties

  18. Soldadura (Welding). Spanish Translations for Welding.

    Science.gov (United States)

    Hohhertz, Durwin

    Thirty transparency masters with Spanish subtitles for key words are provided for a welding/general mechanical repair course. The transparency masters are on such topics as oxyacetylene welding; oxyacetylene welding equipment; welding safety; different types of welds; braze welding; cutting torches; cutting with a torch; protective equipment; arc…

  19. Tube to tubesheet welding by electron beam for heat exchanger application

    International Nuclear Information System (INIS)

    The EB-process can successfully be used to weld in tubes into tubesheet also for those materials which are sensitiv to hot cracking. The range of qualified welding parameters has been evaluated based on a lot of metallographic and microanalysis inspections. To obtain reproducable and perfect welds a microcomputer controlled welding cycle is recommended using beam deflection, automatic seam tracking, beam current- and focus control. The results can be adopted to the specific conditions of mobile welding equipment with local vacuum. (orig.)

  20. WELDING TORCH

    Science.gov (United States)

    Correy, T.B.

    1961-10-01

    A welding torch into which water and inert gas are piped separately for cooling and for providing a suitable gaseous atmosphere is described. A welding electrode is clamped in the torch by a removable collet sleeve and a removable collet head. Replacement of the sleeve and head with larger or smaller sleeve and head permits a larger or smaller welding electrode to be substituted on the torch. (AEC)

  1. Detection of micro-weld joint by magneto-optical imaging

    Science.gov (United States)

    Gao, Xiangdong; Liu, Yonghua; You, Deyong

    2014-10-01

    It is required that the laser beam focus should be controlled to accurately follow the weld joint center during laser butt joint welding; therefore, the weld joint position must be detected automatically in real-time. An approach for detecting the micro-weld joint (weld gap less than 0.1 mm) based on magneto-optical (MO) imaging is investigated during laser butt-joint welding of low carbon steel. Magneto-optical sensor was used to capture the dynamic images of weld joint. Weld MO image gray distribution features were analyzed to extract the transition zone of weld joint. The influences of a different magnetic field intensity and the welding speed on detecting the weld joint position were mainly studied. Under different welding conditions where welding path, weld gap or welding speed varies, it has been found that using magneto-optic imaging technology could effectively detect the position of the micro-weld joint. Different weld joint positions in MO images have been detected with various magnetic field intensities. Experimental results show that the welding speed has little influence on the detection of weld joint position.

  2. Software Design and Application of Automatic Ultrasonic Inspection System for Welded Pipe%焊接钢管超声波自动探伤检测系统的软件设计与应用

    Institute of Scientific and Technical Information of China (English)

    常少文

    2011-01-01

    In this article, the software design and application current status of automatic ultrasonic inspection system for welded pipe were analyzed. Combined traditional ultrasonic non-destructive inspection technology with some advanced technologies, such as industrial control computer, virtual instrument, intelligent flaw detection and so on, through flaw detection operational procedure, the complex flaw echo can be evaluated accurately and selected strictly. This will effectively avoid error alarm; the flaw waveform playback can overcome insufficiency of identifying flaw type. The field service proved that the false alarm rate is lower 2%, and the missing report rate is 0.%分析了焊接钢管超声波自动探伤检测系统的软件设计以及在焊接钢管检测中的应用状况.该系统把传统的超声波无损检测技术和先进的工业控制计算机、虚拟仪器、智能化探伤等技术相结合,通过探伤操作程序,可实现对复杂缺陷回波的准确评价和严格筛选,有效地避免了系统的误报警,而且其缺陷波形回放克服了超声波自动探伤检测中的缺陷种类难以识别的不足.现场使用证明该系统误报率小于2%,漏报率为0.

  3. A Recent Welding Technique: Laser Welding

    OpenAIRE

    ATİK, Dt.Ezgi; CİĞER, Prof. Dr. Semra

    2013-01-01

    Welding is a process that joins two adjacent metal surfaces with or without using filling material. The latest laser welding technique is a technology based on using infrared light spectrum. Laser welding has numerous advantages considering other conventional welding options used in dentistry and because of these reasons laser welding is used widely. When searching the literature in concern with laser welding, it is observed that this technique is compared with other conventional welding meth...

  4. Development of endplug welding technology for irradiation testing capsule

    International Nuclear Information System (INIS)

    To evaluate the performance of newly developed nuclear fuel, it is necessary to irradiate the fuel at a research reactor and examine the irradiated fuel. For the irradiation test in a reasearch reactor, a fuel assembly which is generally called a capsule should be fabricated, considering the fuel irradiation plan and the characteristics of the reactor to be used. And also the fuel elements containing the developed fuel pellets should be made and assembled into a capsule. In this study, the welding method, welding equipment, welding conditions and parameters were developed to make fuel elements for the irradiation test at the HANARO research reactor. The TIG welding method using automatic orbital tube welding system was adopted and the welding joint design was developed for the fabrication of various kinds of irradiation fuel elements. And the optimal welding conditions and parameters were also established for the endplug welding of Zircaloy-4 cladding tube

  5. Application of narrow groove welding process to nuclear pipes

    International Nuclear Information System (INIS)

    Experiments on narrow groove welding with a single string bead deposition per layer were performed using automatic orbital TIG welding equipment, and the narrow groove shape and welding conditions were optimized for stainless steel and carbon steel pipes. The characteristics of narrow groove weld joints of these materials were investigated in the areas of metallurgical structure and mechanical properties. The process of one bead per layer was found to produce a good homogeneous weld and the total weld has the same micro structure between two regular fusion lines and, therefore, uniform mechanical properties. Based on these test results, the narrow groove welding process was applied to butt weld joints for austenitic stainless steel pipe with a large diameter. (author)

  6. Welding technique studies on the "West-East" pipeline project

    Institute of Scientific and Technical Information of China (English)

    Sui Yongli; Du Zeyu; Huang Fuxiang; Qi Lichun

    2006-01-01

    This paper described the work of welding process design for the "West-East" pipeline project, which is high pressure, large diameter and heavy wall thickness. According to the different geographical situation, climate, culture and the flexibility of the welding methods, this work recommended the semi-automatic process at the east and middle sections and automatic process at the west section of the pipeline project. The manual process is recommended on the tie-in joints and repairs. The double joint pipe and the 3 joint pipe are recommended at the water net place and some in-ditch welding place to reduce the welding volume. Also the special redesigned bevels are recommended for the automatic process and the semiautomatic process. Through all destructive tests, the results shows the welds are meet the requirements of related standards,specifications and design documents.

  7. Sensor-guided robotic laser welding

    OpenAIRE

    Graaf, de, Joost

    2007-01-01

    Robotic laserwelding is a promising joining technique for welding of continuous seams in 3D products. High quality joints can be realised provided that the manipulation of the laser beam and the product tolerances meet strict criteria. The requirements for the positioning accuracy of the laser beamcan be fulfilled using seam-tracking sensors. This thesis describes how such sensors can be integrated in a robotic laser welding system for automatic teaching of the seam trajectory, but also to co...

  8. Welding robots

    OpenAIRE

    Pires, J. Norberto; Loureiro, Altino; Godinho, T.; Ferreira, P; Fernando, B; Morgado, J

    2003-01-01

    Using robots in industrial welding operations is common but far from being a streamlined technological process. The problems are with the robots, still in their early design stages and difficult to use and program by regular operators; the welding process, which is complex and not really well known and the human-machine interfaces, which are unnatural and not really working. In this article, these problems are discussed, and a system designed with the double objective of serving R&D efforts o...

  9. Syllabus in Trade Welding.

    Science.gov (United States)

    New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

    The syllabus outlines material for a course two academic years in length (minimum two and one-half hours daily experience) leading to entry-level occupational ability in several welding trade areas. Fourteen units covering are welding, gas welding, oxyacetylene welding, cutting, nonfusion processes, inert gas shielded-arc welding, welding cast…

  10. 小孔径自动钨极氩弧焊在管板焊接中的应用%Application of small hole automatic GTAW for tube-sheet welding

    Institute of Scientific and Technical Information of China (English)

    孟震

    2011-01-01

    This paper introduced a new special welding machine and welding tooling for small hole inside wire filling of tube sheet joint in argon arc welding machine in the tube sheet welding through test and ensured groove preparation methods and welding procedure parameters,by the X-ray test,corrosion test,macro metallographic test,pulled off the test and so on which the results that were satisfactory with welding quality and product requirements.For later the small holes of wire filling welding provides certain theoretical basis for future.%介绍了一种专用于小孔内填丝的新型管板接头氩孤焊机和机头在管板焊接工作中的应用,通过多次规范试验验证并最终确定坡口制备方式和焊接规范参数,焊接后经过射线检测、腐蚀试验、宏观金相试验、拉脱试验等的验证,确保焊接接头获得满意的焊接质量,为以后小孔内填丝焊接制造技术提供了一定的理论基础.

  11. Analisa Ketangguhan dan Struktur Mikro pada Daerah Las dan HAZ Hasil Pengelasan Sumerged Arc Welding pada Baja SM 490

    OpenAIRE

    Yusa Asra Yuli Wardana; Anang Setiawan

    2006-01-01

    Submerged Arc Welding (SAW) is one of method for welding process which used for the extensions of heavy construction, for example bridge construction. Broadness usage of SAW caused by welding process can be done automatically and have high reliability. Microstructure and toughness properties of weld metal were influenced by many factors such as chemical composition, heat input, filler, fluks, etc. This research aim to study influence of heat input. Welding Process was carried out using SAW wi...

  12. Application of gtaw welding robots to nozzles of reactor pressure vessels

    International Nuclear Information System (INIS)

    Application of robot welding can achieve automatic operations in nuclear structures where these are needs for cost reduction and high quality of welding. Robot welding was applied to manufacturing the nozzles of the reactor pressure vessel overlay. Robots were arranged to allow efficient operations and the work-station was constructed. Both an operation program for the robot that can travel automatically on the three-dimensional surface shape of the nozzles and the optimum AVC (Arc Voltage Control) were developed. Results of application of the work-station to manufacturing the nozzles showed automatic operations and high quality welds were achieved. (author)

  13. Application of GTAW welding robots to nozzles of reactor pressure vessels

    International Nuclear Information System (INIS)

    Application of robot welding can achieve automatic operations in nuclear structures where these are needs for cost reduction and high quality of welds. Robot welding was applied to manufacturing the nozzles of the reactor pressure vessel overly. Robots were arranged to allow efficient operations and the work-station was constructed. Both an operation program for the robot that can travel automatically on the three-dimensional surface shape of the nozzles and the optimum AVC (Arc Voltage Control) were developed. Results of application of the work-station to manufacturing the nozzles showed automatic operations and high quality welds were achieved. (author)

  14. The variable polarity plasma arc welding process: Characteristics and performance

    Science.gov (United States)

    Hung, R. J.; Zhu, G. J.

    1991-01-01

    Significant advantages of the Variable Polarity Plasma Arc (VPPA) Welding Process include faster welding, fewer repairs, less joint preparation, reduced weldment distortion, and absence of porosity. The power distribution was analyzed for an argon plasma gas flow constituting the fluid in the VPPA Welding Process. The major heat loss at the torch nozzle is convective heat transfer; in the space between the outlet of the nozzle and the workpiece; radiative heat transfer; and in the keyhole in the workpiece, convective heat transfer. The power absorbed at the workpiece produces the molten puddle that solidifies into the weld bead. Crown and root widths, and crown and root heights of the weld bead are predicted. The basis is provided for an algorithm for automatic control of VPPA welding machine parameters to obtain desired weld bead dimensions.

  15. Technology of laser repair welding of nickel superalloy inner flaps of jet engine

    OpenAIRE

    A. Klimpel; A. Rzeźnikiewicz

    2011-01-01

    Purpose: of this paper: work out laser welding repair technology of cracked MIG 29 jet engine inner flaps made of cast nickel superalloy ŻS-3DK (ЖС-3ДК, Russian designation).Design/methodology/approach: The study were based on the analysis of laser HPDL powder INCONEL 625 welding of nickel superalloy using wide range of welding parameters to provide highest quality repair welds.Findings: Study of automatic welding technologies GTA, PTA and laser HPDL has shown that just laser welding can prov...

  16. Girth welding system for vortex type refrigeration compressor of air conditioner

    Institute of Scientific and Technical Information of China (English)

    Liu Xiaowen; Ma Caixia; Yang Siqian; Hu Jisheng

    2006-01-01

    According to the requirements of welding process for vortex type compressor of air conditioner manufactured in product line, a special girth welding machine with PLC as control core was developed, which had both upright and 45 ° incline service positions. And some key technologies were researched, such as structural design of machine body, reliable conduction of rotary weldments and quality control of welding process and so on. The experimental results showed that this machine could satisfy the requirements of welding quality and girth welding technology, results also proved the machine was a high-efficiency and low-cost automatic welding device.

  17. Innovative Tools Advance Revolutionary Weld Technique

    Science.gov (United States)

    2009-01-01

    (no toxic smoke or shielding gas, liquid metal splatter, arcing, dangerous voltage, or radiation), and environmentally sound (no consumables, fumes, or noise) than fusion welding. Under computer control, an automated FSW machine can create welds with high reproducibility, improving efficiency and overall quality of manufactured materials. The process also allows for welding dissimilar metals as well as those metals considered to be "unweldable" such as the 7xxx series aluminum alloys. Its effectiveness and versatility makes FSW useful for aerospace, rail, automotive, marine, and military applications. A downside to FSW, however, is the keyhole opening left in the weld when the FSW pin tool exits the weld joint. This is a significant problem when using the FSW process to join circumferential structures such as pipes and storage containers. Furthermore, weld joints that taper in material thickness also present problems when using the conventional FSW pin tool, because the threaded pin rotating within the weld joint material is a fixed length. There must be capability for the rotating pin to both increase and decrease in length in real time while welding the tapered material. (Both circumferential and tapered thickness weldments are found in the space shuttle external tank.) Marshall engineers addressed both the keyhole and tapered material thickness problems by developing the auto-adjustable pin tool. This unique piece of equipment automatically withdraws the pin into the tool s shoulder for keyhole closeout. In addition, the auto-adjustable pin tool retracts, or shortens, the rotating pin while welding a weld joint that tapers from one thickness to a thinner thickness. This year, the impact of the Marshall innovation was recognized with an "Excellence in Technology Transfer Award" from the Federal Laboratory Consortium.

  18. Appliances and technologies on mechanical welding of reactor shells

    International Nuclear Information System (INIS)

    Nowadays, welded joints of spherical reactor safety shells are generally and to a large extent produced by manual arc-welding. Mechanized welding methods are to be developed aiming at obtaining better technological quality values, more safety with regard to susceptibility to pores and cracks and more independence from human insufficiency. Due to the lack of special machinery for the required purpose and due to the fact that expensive machinery developments should be avoided, a worldwide search on the market has been effected on the basis of given specifications in order to find convenient welding appliances which can be modified. The problems of the search for machinery as well as of laboratory experiments are shown in this report. An electro-gas/slag vertical welding method shall be developed being economic and assuring the quality values required for the vertical welding. For the welding of the upper and lower parts of the sphere a MIG/MAG-shielded arc-welding method with weld centerline and height-control is required which has to meet the same demands as well as a proper guiding on the shell. The initial experiments at the selected appliances shows the possibility to improve the welding quality considerably by mechanizing. The following topics are discussed in detail: sensor systems, oscillating systems, subsequent systems, electro-slag-high-speed-welding in single pass technique, machinery developments, pass and capping pass electro-slag-high-speed welding. Analysis of the used starting-, admixture- and auxilary material, testing conditions and welding parameters, quality values achieved at electro-slag-welds. Automatic MIG/MAG oscillating machines with electronic weld centerline and height control. Systems with the electric arc acting as sensor. Sources of current. (orig.)

  19. Automatic sequences

    CERN Document Server

    Haeseler, Friedrich

    2003-01-01

    Automatic sequences are sequences which are produced by a finite automaton. Although they are not random they may look as being random. They are complicated, in the sense of not being not ultimately periodic, they may look rather complicated, in the sense that it may not be easy to name the rule by which the sequence is generated, however there exists a rule which generates the sequence. The concept automatic sequences has special applications in algebra, number theory, finite automata and formal languages, combinatorics on words. The text deals with different aspects of automatic sequences, in particular:· a general introduction to automatic sequences· the basic (combinatorial) properties of automatic sequences· the algebraic approach to automatic sequences· geometric objects related to automatic sequences.

  20. High quality joining techniques: in-process assurance (IPA) welding system

    International Nuclear Information System (INIS)

    On July 1, 1995, the Product Liability Law was enforced, and in industrial world, further reliability has been demanded. Recently, accompanying the progress of electronics, the proportion taken by automatic welders and robots increased in welding. By memorizing proper welding conditions, the welding from initial to final passes can be done fully automatically. Also feedback mechanism was equipped to mechanized welders, and the in-process control has become to be feasible. The way of thinking on confirming in process welding quality in arc welding is explained. IPA welding system utilizes the multi-media collecting images and sound, samples the change of welding conditions and the state of arc on a same screen, and monitors the deviation from the range of proper welding conditions. At the time of abnormality, inspector or a computer carries out image diagnosis and welding control, and the system indicates the soundness of welded parts. The basic concept and the flow chart of this system are shown. The experiment of applying the system to arc welding is reported. The correlation of welding phenomena and welding conditions is examined. (K.I.)

  1. Study on Sensor Design Technique for Real-Time Robotic Welding Tracking System

    International Nuclear Information System (INIS)

    Based on visual measurement techniques, the real-time robotic welding tracking system achieves real-time adjustment for robotic welding according to the position and shape changes of a workpiece. In system design, the sensor design technique is so important that its performance directly affects the precision and stability of the tracking system. Through initiative visual measurement technology, a camera unit for real-time sampling is built with multiple-strip structured light and a high-performance CMOS image sensor including 1.3 million pixels; to realize real-time data process and transmission, an image process unit is built with FPGA and DSP. Experiments show that the precision of this sensor reaches 0.3mm, and band rate comes up to 10Mbps, which effectively improves robot welding quality.With the development of advanced manufacturing technology, it becomes an inexorable trend to realize the automatic, flexible and intelligent welding product manufacture. With the advantage of interchangeability and reliability, robotic welding can boost productivity, improve work condition, stabilize and guarantee weld quality, and realize welding automation of the short run products [1]. At present, robotic welding has already become the application trend of automatic welding technology. Traditional welding robots are play-back ones, which cannot adapt environment and weld distortion. Especially in the more and more extensive arc-welding course, the deficiency and limitation of play-back welding technology becomes more prominent because of changeable welding condition. It becomes one of the key technology influencing the development of modern robotic welding technology to eliminate or decrease uncertain influence on quality of welding such as changing welding condition etc [2]. Based on visual measuring principle, this text adopts active visual measuring technology, cooperated with high-speed image process and transmission technology to structure a tracking sensor, to realize

  2. Distortion Control during Welding

    OpenAIRE

    Akbari Pazooki, A.M.

    2014-01-01

    The local material expansion and contraction involved in welding result in permanent deformations or instability i.e., welding distortion. Considerable efforts have been made in controlling welding distortion prior to, during or after welding. Thermal Tensioning (TT) describes a group of in-situ methods to control welding distortion. In these methods local heating and/or cooling strategies are applied during welding. Additional heating and/or cooling sources can be implemented either stationa...

  3. Development of remote-operating welding system of canister cap

    International Nuclear Information System (INIS)

    The authors have developed a remote-operating welding system for mock-up test facilities of vitrification process of high level radio-active waste of nuclear fuel. This system enables cap sealing welding of canister to accomodate a vitrified waste. Supposing the operation is conducted under high level radio-active environment, the system has been considered to be well handled remotely by adopting guide-pin connection of the welding head, and also developing the automatic electrode exchanger, detecting method of work piece set location by means of the electrode itself as a sensor, slipping joint of power cable (work piece side) and shielding gas quality checking method by measuring an arc voltage changes. To ensure high quality welding, welding conditions were fully examined and established according to temperatures of the work piece before welding. (author)

  4. Embrittlement of welded joints

    International Nuclear Information System (INIS)

    The structure of a weld is considered and the role of the main parts of a welded joint in the appearance of defects during welding is determined. Factors greatly affecting hot crack formation (heat removal, impurity redistribution, volume of welding bath, welding rate) are shown. Reasons for the appearance of cracks not related to crystallization process (subsequent heat treatment, plastic working, etc.) are analyzed. The process of cold cracking of welds due to hydrogen absorption and relaxation of high welding stresses, is investigated. Methods to avoid cold cracking are described. Mechanisms of weld embrittlement are considered using as examples steels and high nickel alloys. 248 refs.; 28 figs.; 2 tabs

  5. Development of automatic pipe welder for nuclear power plant

    International Nuclear Information System (INIS)

    Numerous pipings are installed in nuclear power plants, and of course, the reliability of these pipings are very important to preserve the safety of the plants. These pipings undergo periodic inspection yearly, and when some defects are found or some reconstructions to superior systems are made, field welding in the plants is required. When the places to be welded are in containment vessels, the works must be carried out in radiation environment. In order to maintain the highest quality of welding and to reduce the radiation exposure of workers, many skilled workers are required. This automatic pipe welder was developed to solve these problems, aiming at carrying out welding works by remote control at the safe places outside containment vessels. Especially in order to obtain the highest quality of welding, it was not perfectly automated, but the man-machine system so as to enable to utilize the delicate sense of workers was adopted. The visual and contact detecting systems to monitor welding works, remote control system, computer control, light, small and easily installed welding head, grinding and supersonic flow detecting equipments, the power source of transistor switching type, air cooling equipment, and the function for setting welding conditions according to algorithm were added to the welding machine. The outline and main components of this automatic pipe welder are explained. (Kako, I.)

  6. Welding processes handbook

    CERN Document Server

    Weman, Klas

    2011-01-01

    Offers an introduction to the range of available welding technologies. This title includes chapters on individual techniques that cover principles, equipment, consumables and key quality issues. It includes material on such topics as the basics of electricity in welding, arc physics, and distortion, and the weldability of particular metals.$bThe first edition of Welding processes handbook established itself as a standard introduction and guide to the main welding technologies and their applications. This new edition has been substantially revised and extended to reflect the latest developments. After an initial introduction, the book first reviews gas welding before discussing the fundamentals of arc welding, including arc physics and power sources. It then discusses the range of arc welding techniques including TIG, plasma, MIG/MAG, MMA and submerged arc welding. Further chapters cover a range of other important welding technologies such as resistance and laser welding, as well as the use of welding techniqu...

  7. Friction Stir Welding

    Science.gov (United States)

    Nunes, Arthur C., Jr.

    2008-01-01

    Friction stir welding (FSW) is a solid state welding process invented in 1991 at The Welding Institute in the United Kingdom. A weld is made in the FSW process by translating a rotating pin along a weld seam so as to stir the sides of the seam together. FSW avoids deleterious effects inherent in melting and promises to be an important welding process for any industries where welds of optimal quality are demanded. This article provides an introduction to the FSW process. The chief concern is the physical effect of the tool on the weld metal: how weld seam bonding takes place, what kind of weld structure is generated, potential problems, possible defects for example, and implications for process parameters and tool design. Weld properties are determined by structure, and the structure of friction stir welds is determined by the weld metal flow field in the vicinity of the weld tool. Metal flow in the vicinity of the weld tool is explained through a simple kinematic flow model that decomposes the flow field into three basic component flows: a uniform translation, a rotating solid cylinder, and a ring vortex encircling the tool. The flow components, superposed to construct the flow model, can be related to particular aspects of weld process parameters and tool design; they provide a bridge to an understanding of a complex-at-first-glance weld structure. Torques and forces are also discussed. Some simple mathematical models of structural aspects, torques, and forces are included.

  8. Welding and cutting '93. Lectures

    International Nuclear Information System (INIS)

    This volume contains 46 lectures on the following ten groups of subjects: New knowledge and experience for welding firms; European welding process testing; welding developments in Europe - process and equipment; progress in material technique; accreditation and certification in the Single European Market; development of equipment in welding and cutting techniques; quality assurance in welding technique; welding additives and welding aid materials; work and health protection in welding technique; training and qualification of personnel; basis of welding technique in Europe - test technique. (MM)

  9. Investigation of Effect of Welding Current on Welding Penetration in Covered Electrode Arc Welding And MIG Welding

    OpenAIRE

    Bekir ÇEVİK

    2013-01-01

    In this study, the effect of welding current on penetration in covered electrode arc welding and MIG (Metal Inert Gas) welding was investigated. St 37 quality steel materials were used in the experiments. Three different welding current (60, 90 and 120 A with covered electrode arc welding, 100, 125 and 155 A with MIG welding) was selected for welding process and was made 200 mm long weld. The welded specimens were cut particular lengths, then metallographic tests were performed. As a result o...

  10. Introduction to Welding.

    Science.gov (United States)

    Fortney, Clarence; Gregory, Mike

    This curriculum guide provides six units of instruction on basic welding. Addressed in the individual units of instruction are the following topics: employment opportunities for welders, welding safety and first aid, welding tools and equipment, basic metals and metallurgy, basic math and measuring, and procedures for applying for a welding job.…

  11. Distortion Control during Welding

    NARCIS (Netherlands)

    Akbari Pazooki, A.M.

    2014-01-01

    The local material expansion and contraction involved in welding result in permanent deformations or instability i.e., welding distortion. Considerable efforts have been made in controlling welding distortion prior to, during or after welding. Thermal Tensioning (TT) describes a group of in-situ met

  12. Ultrasonic examination of stainless steel EB welds by an immersion technique

    International Nuclear Information System (INIS)

    The authors report the development of an ultrasonic examination method of austenitic stainless steel electron beam (EB) welds. This method is based on an automatic immersion technique employing focused transducers and is aimed at detecting both the weld soundness and penetration. The authors describe the examination procedure with a calibration of the ultrasonic equipment, a complete weld scanning, and a repetition of the calibration for matters of verification. They also describe how results are interpreted in terms of wave soundness (attenuation) and weld penetration. They discuss the reliability of the examination procedure. They comment results obtained for EB butt welds in a AISI 304 pipe

  13. Laser welding in space

    Science.gov (United States)

    Kaukler, W. F.; Workman, G. L.

    1991-01-01

    Autogenous welds in 304 stainless steel were performed by Nd-YAG laser heating in a simulated space environment. Simulation consists of welding on the NASA KC-135 aircraft to produce the microgravity and by containing the specimen in a vacuum chamber. Experimental results show that the microgravity welds are stronger, harder in the fusion zone, have deeper penetration and have a rougher surface rippling of the weld pool than one-g welds. To perform laser welding in space, a solar-pumped laser concept that significantly increases the laser conversion efficiency and makes welding viable despite the limited power availability of spacecraft is proposed.

  14. Orbital welding technique

    International Nuclear Information System (INIS)

    The TIG (Tungsten-inert gas) orbital welding technique is applied in all areas of pipe welding. The process is mainly used for austenitic and ferritic materials but also for materials like aluminium, nickel, and titanium alloys are commonly welded according to this technique. Thin-walled as well as thick-walled pipes are welded economically. The application of orbital welding is of particular interest in the area of maintenance of thick-walled pipes that is described in this article. (orig.)

  15. Advanced Welding Applications

    Science.gov (United States)

    Ding, Robert J.

    2010-01-01

    Some of the applications of advanced welding techniques are shown in this poster presentation. Included are brief explanations of the use on the Ares I and Ares V launch vehicle and on the Space Shuttle Launch vehicle. Also included are microstructural views from four advanced welding techniques: Variable Polarity Plasma Arc (VPPA) weld (fusion), self-reacting friction stir welding (SR-FSW), conventional FSW, and Tube Socket Weld (TSW) on aluminum.

  16. Development of an auto-welding system for CRD nozzle repair welds using a 3D laser vision sensor

    International Nuclear Information System (INIS)

    A control rod device (CRD) nozzle attaches to the hemispherical surface of a reactor head with J-groove welding. Primary water stress corrosion cracking (PWSCC) causes degradation in these welds, which requires that these defect areas be repaired. To perform this repair welding automatically on a complicated weld groove shape, an auto-welding system was developed incorporating a laser vision sensor that measures the 3-dimensional (3D) shape of the groove and a weld-path creation program that calculates the weld-path parameters. Welding trials with a J-groove workpiece were performed to establish a basis for developing this auto-welding system. Because the reactor head is placed on a lay down support, the outer-most region of the CRD nozzle has restricted access. Due to this tight space, several parameters of the design, such as size, weight and movement of the auto-welding system, had to be carefully considered. The cross section of the J-groove weld is basically an oval shape where the included angle of the J-groove ranges from 0 to 57 degrees. To measure the complex shape, we used double lasers coupled to a single charge coupled device (CCD) camera. We then developed a program to generate the weld-path parameters using the measured 3D shape as a basis. The program has the ability to determine the first and final welding positions and to calculate all weld-path parameters. An optimized image-processing algorithm was applied to resolve noise interference and diffused reflection of the joint surfaces. The auto-welding system is composed of a 4-axis manipulator, gas tungsten arc welding (GTAW) power supply, an optimized designed and manufactured GTAW torch and a 3D laser vision sensor. Through welding trials with 0 and 38-degree included-angle workpieces with both J-groove and U-groove weld, the performance of this auto-welding system was qualified for field application

  17. Welding repair of a dissimilar weld and respective consequences for other German plants

    International Nuclear Information System (INIS)

    During a regular refueling outage in a German nuclear power plant in year 2000, additional non-destructive examinations have been performed on request of the Authority, to fulfill some recommendations of the independent experts with regard to the retrospective application of the Basic Safety Concept for the ferritic main coolant piping of this plant. During these inspections, indications were found in a dissimilar weld between one of the fifteen MCL (main coolant lines) nozzles and the ECC (emergency core cooling) system piping. By means of on-site metallography and laboratory investigations on three boat samples taken from this weld, it could be shown that the indications were due to hot cracking in the surface layer of the weld. In the course of these investigations, at three locations at the circumference of the weld, dis-bonding defects were found between the ferritic base metal of the nozzle and the austenitic weld butter, which has been applied to join the nozzle to the austenitic safe-end. According to the results of the extensive investigations, the dis-bonding occurred during the manufacturing process after stress-relief heat-treatment of the buttering during the welding of the austenitic safe-end to the butter material. There was no evidence for any crack growth during operation of the plant. Due to the large size of the boat-samples, a weld repair was mandatory. This repair has been performed using the so-called temper-bead technique as specified in the ASME Code, without subsequent stress relief heat treatment, using an advanced automatic orbital TIG welding process. The welding has been successfully performed without the need of further repair work. For those dissimilar welds, all other plants, except one, had used Inconel welding material for buttering the ferritic nozzle instead of stainless steel welding metal. For metallurgical reasons, dis-bonding along the fusion line for Inconel buttered dissimilar welds is unlikely to occur. Nevertheless all

  18. Narrow groove gas tungsten arc welding of ASTM A508 Class 4 steel for improved toughness properties

    Energy Technology Data Exchange (ETDEWEB)

    Penik, M.A. Jr. [Rensselaer Polytechnic Inst., Troy, NY (United States)

    1997-04-01

    Welding of heavy section steel has traditionally used the automatic submerged arc welding (ASAW) process because of the high deposition rates achievable. However, the properties, particularly fracture toughness, of the weld are often inferior when compared to base material. This project evaluated the use of narrow groove gas tungsten arc welding (GTAW) to improve weld material properties. The welding procedures were developed for ASTM A508 Class 4 base material using a 1% Ni filler material complying to AWS Specification A.23-90-EF3-F3-N. A narrow groove joint preparation was used in conjunction with the GTAW process so competitive fabrication rates could be achieved when compared to the ASAW process. Weld procedures were developed to refine weld substructure to achieve better mechanical properties. Two heaters of weld wire were used to examine the effects of minor filler metal chemistry differences on weld mechanical properties. Extensive metallographic evaluations showed excellent weld quality with a refined microstructure. Chemical analysis of the weld metal showed minimal weld dilution by the base metal. Mechanical testing included bend and tensile tests to ensure weld quality and strength. A Charpy impact energy curve versus temperature and fracture toughness curve versus temperature were developed for each weld wire heat. Results of fracture toughness and Charpy impact testing indicated an improved transition temperature closer to that of the base material properties.

  19. Mechanical properties of austenitic stainless steel welded joints at high temperature

    International Nuclear Information System (INIS)

    Different test methods to define the characteristics of joints and their behavior in service are discussed, and various processes used in industrial projects are considered. The choice of process depends on many factors; thickness of the parts to be assembled, geometry of the joints etc... For construction designed to work at high temperature the reference process is manual welding. Electron welding and certain automatic welding methods are also examined

  20. The MSDT - 01 machine for end-cap - can welding

    International Nuclear Information System (INIS)

    This machine is used in semi-automatic welding by electric resistance of end-caps on the nuclear fuel cans used in CANDU type reactors. General constructive, dimensional and operational characteristics are given as well as the specific power consumption requirements. The machine has a yield of 105 cans/hour. The net mass is 900 kg. Two novel features as compared with the reference Canadian model are focussed: - an electronic transducer is provided with a display indicating the can's shortening during the welding process; - a pressure proportional regulator is introduced for optimizing the electrode thrust during welding process

  1. Diffusion welding

    International Nuclear Information System (INIS)

    After a brief recall of the principle, and of the advantages of the method, we give some examples of metallic bonding in a first part where we describe preliminary trials: Ta-Mo, Zr-Zr, Zr-Nb, Nb-stainless steel, Mo-stainless steel, aluminium-aluminium (A5-A5). The second part of the note is devoted to trials on construction elements: on tubular elements for bonding between Mo or Nb on one hand, and stainless steel on the other hand (We indicate in what conditions the bonding are tight and what are their mechanical strength and their resistance to thermic cycles). We indicate, in this chapter, a method to obtain radiation windows in Be welded on an element made of stainless steel. (authors)

  2. Development of automated ultrasonic testing machine for PHWR endclosure welds

    International Nuclear Information System (INIS)

    PHWR fuel bundle essentially consists of a cluster of fuel elements whose ends are welded by endplates to form a bundle. Each fuel pin consists of loaded with sintered UO2 pellets and the tube ends are hermetically sealed by resistance welding. The end- cap weld of the fuel element is the most critical operation during the fabrication of PHWR fuel bundles. The weld has to maintain its integrity in the harsh reactor environment throughout its residence in the reactor. Any failure in the weld will lead to leakage of fission product in to the coolant circuit. In order to ensure the end-cap weld integrity, stringent quality control procedures are followed. The quality assurance procedure involves qualification of men and machines, while inspection techniques involve both destructive and non-destructive testing, metallographic weld evaluation is carried out on sampling basis. Therefore the paper brings out the details of design and performance of the new semi automatic computerized ultrasonic testing system for PHWR fuel elements. The paper brings out the details of design and performance of the new semi automatic computerized ultrasonic testing system for PHWR fuel elements

  3. Laser Seam welding method

    International Nuclear Information System (INIS)

    The present invention provides a laser seam welding method for welding spacers to be used in nuclear fuel assemblies at a stable quality. Namely, the laser seam welding method comprises irradiating, while moving, laser beams to a portion to be welded. In this case, data of the shapes and characteristics of the portion to be welded are inputted to restrict the range of the welding of the portion to be welded. The power, moving speed, distance to a focal point and energy of the laser beams are controlled in the midway of the range for the welding. Then, a welding nugget having a shape defined to a portion to be welded can be formed thereby enabling to keep the portion to be welded to stable quality. As a result, failed welding can be eliminated, and strength of joint can be guaranteed. In addition, auxiliary products of portions to be welded, for example, springs are not failed by laser beams. As a result, satisfactory spacers can be provided. (I.S.)

  4. Thermal strain effect of welding on the properties and stress state of welded joints in the pressure vessel of the A 1 reactor

    International Nuclear Information System (INIS)

    Results are presented of welding and detailed evaluation of test plates and rings of actual sizes, and the results are related directly to the determination of the thermal conditions of the welding of the A1 steel reactor vessel. Electro slag welding and automatic C02 welding were used. Details are given of the materials used and the conditions of the tests. Test results and analysis are given under the following heads: thermal cycles, microstructure, notch toughness; strain effect, stress state, specific accumulated energy; temperature of brittle crack initiation, the critical size of the initial flaw; conclusions. (U.K.)

  5. Handbook of Plastic Welding

    DEFF Research Database (Denmark)

    Islam, Aminul

    The purpose of this document is to summarize the information about the laser welding of plastic. Laser welding is a matured process nevertheless laser welding of micro dimensional plastic parts is still a big challenge. This report collects the latest information about the laser welding of plastic...... materials and provides an extensive knowhow on the industrial plastic welding process. The objectives of the report include: - Provide the general knowhow of laser welding for the beginners - Summarize the state-of-the-art information on the laser welding of plastics - Find the technological limits in terms...... of design, materials and process - Find the best technology, process and machines adaptive to Sonion’s components - Provide the skills to Sonion’s Design Engineers for successful design of the of the plastic components suitable for the laser welding The ultimate goal of this report is to serve as a...

  6. Position welding using disk laser-GMA hybrid welding

    OpenAIRE

    C.-H. Kim; H.-S. Lim; J.-K. Kim

    2008-01-01

    Purpose: Position welding technology was developed by using disk laser-GMA hybrid welding in this research.Design/methodology/approach: The effect of hybrid welding parameters such as the shielding gas composition and laser-arc interspacing distance were investigated for the bead-on-plate welding. The pipe girth welding was implemented and the adequate arc welding parameters were selected according to the welding position from a flat position to an overhead position.Findings: The optimized sh...

  7. Characteristics of Welding Fumes

    OpenAIRE

    Johansson, Gerd; Malmqvist, Klas; Bohgard, Mats; Akselsson, Roland

    1981-01-01

    The aerosols from 13 common electric arc welding processes have been characterized regarding total emission, particle size distribution, elemental composition and, when applicable, the oxidation state of chromium. The characterizations have been performed systematically for different combinations of welding current and welding voltage.

  8. Instructional Guidelines. Welding.

    Science.gov (United States)

    Fordyce, H. L.; Doshier, Dale

    Using the standards of the American Welding Society and the American Society of Mechanical Engineers, this welding instructional guidelines manual presents a course of study in accordance with the current practices in industry. Intended for use in welding programs now practiced within the Federal Prison System, the phases of the program are…

  9. Welding Course Curriculum.

    Science.gov (United States)

    Genits, Joseph C.

    This guide is intended for use in helping students gain a fundamental background on the major aspects of the welding trade. The course emphasis is on mastery of the manipulative skills necessary to develop successful welding techniques and on acquisition of an understanding of the specialized tools and equipment used in welding. The first part…

  10. Active weld control

    Science.gov (United States)

    Powell, Bradley W.; Burroughs, Ivan A.

    1994-01-01

    Through the two phases of this contract, sensors for welding applications and parameter extraction algorithms have been developed. These sensors form the foundation of a weld control system which can provide action weld control through the monitoring of the weld pool and keyhole in a VPPA welding process. Systems of this type offer the potential of quality enhancement and cost reduction (minimization of rework on faulty welds) for high-integrity welding applications. Sensors for preweld and postweld inspection, weld pool monitoring, keyhole/weld wire entry monitoring, and seam tracking were developed. Algorithms for signal extraction were also developed and analyzed to determine their application to an adaptive weld control system. The following sections discuss findings for each of the three sensors developed under this contract: (1) weld profiling sensor; (2) weld pool sensor; and (3) stereo seam tracker/keyhole imaging sensor. Hardened versions of these sensors were designed and built under this contract. A control system, described later, was developed on a multiprocessing/multitasking operating system for maximum power and flexibility. Documentation for sensor mechanical and electrical design is also included as appendices in this report.

  11. Comparing Laser Welding Technologies with Friction Stir Welding for Production of Aluminum Tailor-Welded Blanks

    Energy Technology Data Exchange (ETDEWEB)

    Hovanski, Yuri; Carsley, John; Carlson, Blair; Hartfield-Wunsch, Susan; Pilli, Siva Prasad

    2014-01-15

    A comparison of welding techniques was performed to determine the most effective method for producing aluminum tailor-welded blanks for high volume automotive applications. Aluminum sheet was joined with an emphasis on post weld formability, surface quality and weld speed. Comparative results from several laser based welding techniques along with friction stir welding are presented. The results of this study demonstrate a quantitative comparison of weld methodologies in preparing tailor-welded aluminum stampings for high volume production in the automotive industry. Evaluation of nearly a dozen welding variations ultimately led to down selecting a single process based on post-weld quality and performance.

  12. Development of Multi-Purpose Jig for Laser Welding

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Sung-Ho; Hong, Jintae; Joung, Chang-Young; Kim, Ka-Hye [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    A Nuclear Fuel Test Rig, which is designed to investigate nuclear fuel, need hundreds of detailed component assembly or welding processes. To weld small and complicate components, the laser welding process is one of the most important processes in fabricating a Nuclear Fuel Test Rig. Joung developed an automatic Laser Welding System. Hong analyzed the welding properties of Zircaloy-4 and STS 316L of the rig's material. Kim used a Dual Cooled Fuel Test Rig. In this study, a Multi-Purpose Jig, which is able to change the angle and fix the center of the Mother material to help the Laser welding system, is described. In this study, a Multi-Purpose Jig available in fabricating a nuclear fuel test rig was developed. Using the developed Multi-Purpose Jig, butt and lap welding experiments are currently in progress. As a result, it was confirmed that precise fixing and support are possible. Using the developed jig, the workability and accuracy of the laser welding for small components were dramatically improved.

  13. Development of Multi-Purpose Jig for Laser Welding

    International Nuclear Information System (INIS)

    A Nuclear Fuel Test Rig, which is designed to investigate nuclear fuel, need hundreds of detailed component assembly or welding processes. To weld small and complicate components, the laser welding process is one of the most important processes in fabricating a Nuclear Fuel Test Rig. Joung developed an automatic Laser Welding System. Hong analyzed the welding properties of Zircaloy-4 and STS 316L of the rig's material. Kim used a Dual Cooled Fuel Test Rig. In this study, a Multi-Purpose Jig, which is able to change the angle and fix the center of the Mother material to help the Laser welding system, is described. In this study, a Multi-Purpose Jig available in fabricating a nuclear fuel test rig was developed. Using the developed Multi-Purpose Jig, butt and lap welding experiments are currently in progress. As a result, it was confirmed that precise fixing and support are possible. Using the developed jig, the workability and accuracy of the laser welding for small components were dramatically improved

  14. Quality assurance and control for robotic GMA welding

    International Nuclear Information System (INIS)

    A quality assurance (QA) model has been developed. This model systematically considers the relevant activities before, during and after the welding operations with respect to quality. Efficient quality assurance requires that the functionality of the present robotic welding systems needs to be increased and that the knowledge of the personnel involved in the design and production needs to be improved. The collaboration between different departments and personnel needs also to be improved. The procedure specification aspects have been studied and a method for the determination of optimal welding parameters is presented with regards to process stability, quality requirements and productivity. A main productivity problem of robotic welding systems for small series production is due to the time spent on the specification of welding procedures. In order to improve the efficiency, expert systems technology has been studied and applied to automatically generate optimal welding procedures. An objective method for the assessment of process stability has been developed, based upon the analysis of the electrical signals of welding arcs. Furthermore, a method has been developed to monitor the process stability. It is found that it is possible to identify the causes of the disturbance of process stability and to predict the weld quality characteristics based on the analysis of the electrical signals. Though quality is formed during the welding operation, the diagnosis of the causes of quality disturbances is important for the prevention of quality problems of subsequent welds and has been discussed. To assist the operators, expert systems technology is also applied. Further work should be directed to the integration of various QA functions in the robotic arc welding system so that both quality and productivity aspects of the system ban be further improved. (au)

  15. Sturdy on Orbital TIG Welding Properties for Nuclear Fuel Test Rod

    Energy Technology Data Exchange (ETDEWEB)

    Joung, Changyoung; Hong, Jintae; Kim, Kahye; Huh, Sungho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    We developed a precision TIG welding system that is able to weld the seam between end-caps and a fuel cladding tube for the nuclear fuel test rod and rig. This system can be mainly classified into an orbital TIG welder (AMI, M-207A) and a pressure chamber. The orbital TIG welder can be independently used, and it consists of a power supply unit, a microprocessor, water cooling unit, a gas supply unit and an orbital weld head. In this welder, the power supply unit mainly supplies GTAW power for a welding specimen and controls an arc starting of high frequency, supping of purge gas, arc rotation through the orbital TIG welding head, and automatic timing functions. In addition, the pressure chamber is used to make the welded surface of the cladding specimen clean with the inert gas filled inside the chamber. To precisely weld the cladding tube, a welding process needs to establish a schedule program for an orbital TIG welding. Therefore, the weld tests were performed on a cladding tube and dummy rods under various conditions. This paper describes not only test results on parameters of the purge gas flow rates and the chamber gas pressures for the orbital TIG welding, but also test results on the program establishment of an orbital TIG welding system to weld the fuel test rods. Various welding tests were performed to develop the orbital TIG welding techniques for the nuclear fuel test rod. The width of HAZ of a cladding specimen welded with the identical power during an orbital TIG welding cycle was continuously increased from a welded start-point to a weld end-point because of heat accumulation. The welding effect of the PGFR and CGP shows a relatively large difference for FSS and LSS. Each hole on the cladding specimens was formed in the 1bar CGP with the 20L/min PGFR but not made in the case of the PGFR of 10L/min in the CGP of 2bar. The optimum schedule program of the orbital TIG welding system to weld the nuclear fuel test rod was established through the program

  16. Sturdy on Orbital TIG Welding Properties for Nuclear Fuel Test Rod

    International Nuclear Information System (INIS)

    We developed a precision TIG welding system that is able to weld the seam between end-caps and a fuel cladding tube for the nuclear fuel test rod and rig. This system can be mainly classified into an orbital TIG welder (AMI, M-207A) and a pressure chamber. The orbital TIG welder can be independently used, and it consists of a power supply unit, a microprocessor, water cooling unit, a gas supply unit and an orbital weld head. In this welder, the power supply unit mainly supplies GTAW power for a welding specimen and controls an arc starting of high frequency, supping of purge gas, arc rotation through the orbital TIG welding head, and automatic timing functions. In addition, the pressure chamber is used to make the welded surface of the cladding specimen clean with the inert gas filled inside the chamber. To precisely weld the cladding tube, a welding process needs to establish a schedule program for an orbital TIG welding. Therefore, the weld tests were performed on a cladding tube and dummy rods under various conditions. This paper describes not only test results on parameters of the purge gas flow rates and the chamber gas pressures for the orbital TIG welding, but also test results on the program establishment of an orbital TIG welding system to weld the fuel test rods. Various welding tests were performed to develop the orbital TIG welding techniques for the nuclear fuel test rod. The width of HAZ of a cladding specimen welded with the identical power during an orbital TIG welding cycle was continuously increased from a welded start-point to a weld end-point because of heat accumulation. The welding effect of the PGFR and CGP shows a relatively large difference for FSS and LSS. Each hole on the cladding specimens was formed in the 1bar CGP with the 20L/min PGFR but not made in the case of the PGFR of 10L/min in the CGP of 2bar. The optimum schedule program of the orbital TIG welding system to weld the nuclear fuel test rod was established through the program

  17. 油气输送埋弧焊接钢管超声波自动探伤系统的研制与应用%Development and Application of Ultrasonic Automatic Flaw Detection System for Oil and Gas Pipeline Submerged Arc Welded Steel Pipe

    Institute of Scientific and Technical Information of China (English)

    常少文; 吕育栋; 曹华勇; 田岩平; 刘常庆; 韩玉朝; 孙志敏

    2012-01-01

    分析了油气输送埋弧痒接钢管超声波自动探伤系统的组成结构、检测原理、实施方案以及应用状况。该系统采用单元化和模块化结构设计,可任意组合成探伤通道数为1~N的数字化多通道超声波自动探伤系统。配合探伤操作程序,可做到对复杂缺陷回波的准确评价和严格筛选,有效地避免了系统的误报警,实现了缺陷的自动判别、自动报警、自动存储和缺陷波形动态回放,提高了超声波自动探伤检测的准确性和可靠性,误判率〈2%,漏检率为0。%The structure, inspection theory and construction scheme of an ultrasonic automatm flaw ctetecuon system for oil and gas pipeline submerged arc welded steel pipe, together with its application, are introduced. It uses the modular structure and can be any combination of 1 to N channels of a multi-channel digital ultrasonic automatic flaw detection systerrL With the careful program of flaw detection operation, it can evaluate correctly and select strictly for complex flaw echo, and its error in alarm can be effectively avoided. The review of flaw echo waveform overcomes insufficiency of flaw category nondescript in ultrasonic automatic inspection, and achieves misinformation rate smaller than 2%, fail to report rate to 0.

  18. Effect of welding parameters of Gas Metal Arc welding on weld bead geometry: A Review

    Directory of Open Access Journals (Sweden)

    Pushp Kumar Baghel

    2012-07-01

    Full Text Available Weld quality comprises bead geometry and its microstructure, which influence the mechanical properties of the weld. This brief review illustrates the effect of pulse parameters on weld quality. The responsefactors, namely bead penetration, weld width, reinforcement height, weld penetration shape factor and weld reinforcement form factor as affected by arc voltage, wire feed rate, welding speed, gas flow rate and nozzle-toplate distance has also been analysed

  19. Pulsed orbital welding of pipelines; Orbitalschweissen mit Impulstechnik zum Verbinden von Rohren

    Energy Technology Data Exchange (ETDEWEB)

    Aichele, G. [Ingenieurbuero fuer Schweisstechnik, Freiburg (Germany)

    2001-04-30

    In the orbital welding technique, the WIG welding torch circulates over the weld at constant speed. The arc length is controlled automatically by a voltage-dependent control system. The pulse generator is integrated in the motor or the welding torch and ensures accurate positioning. [German] Beim Orbitalschweissen wird der WIG-Schweissbrenner mit konstanter Geschwindigkeit in einer Kreisbahn ueber den Schweissstoss gefuehrt. Die Laenge des Lichtbogens kann mit einer spannungsabhaengigen Steuerung automatisch geregelt werden. Der im Antriebsmotor der Schweisszange eingebaute Impulsgeber sorgt fuer eine genaue Positionsangabe. (orig.)

  20. Fatigue of welded joint in a stainless steel AISI 304 L

    International Nuclear Information System (INIS)

    The flexion fatigue behavior for the base metal and welded joint of an AISI 304 L stainless steel type, used in the Angra-1 reactor, was determined. An automatic welding process was used with improved procedures in order to assure better welding metallurgy. Fatigue tests samples reinforcements were done to allow the evaluation of metallurgical variables, specially the role played by delta ferrite. The resulting welded joint showed better fatigue life than the base metal. Delta ferrite was found to play an important role on the initiation and propagation processes of the fatigue cracks. (Author)

  1. Automatic Compensation of Workpiece Positioning Tolerances for Precise Laser

    Directory of Open Access Journals (Sweden)

    N. C. Stache

    2008-01-01

    Full Text Available Precise laser welding plays a fundamental role in the production of high-tech goods, particularly in precision engineering. In this working field, precise adjustment and compensation of positioning tolerances of the parts to be welded with respect to the laser beam is of paramount importance. This procedure mostly requires tedious and error-prone manual adjustment, which additionally results in a sharp increase in production costs. We therefore developed a system which automates and thus accelerates this procedure significantly. To this end, the welding machine is equipped with a camera to acquire high resolution images of the parts to be welded. In addition, a software framework is developed which enables precise automatic position detection of these parts and adjusts the position of the welding contour correspondingly. As a result, the machine is rapidly prepared for welding, and it is much more flexible in adapting to unknown parts.This paper describes the entire concept of extending a conventional welding machine with means for image acquisition and position estimation. In addition to this description, the algorithms, the results of an evaluation of position estimation, and a final welding result are presented. 

  2. Position welding using disk laser-GMA hybrid welding

    Directory of Open Access Journals (Sweden)

    C.-H. Kim

    2008-05-01

    Full Text Available Purpose: Position welding technology was developed by using disk laser-GMA hybrid welding in this research.Design/methodology/approach: The effect of hybrid welding parameters such as the shielding gas composition and laser-arc interspacing distance were investigated for the bead-on-plate welding. The pipe girth welding was implemented and the adequate arc welding parameters were selected according to the welding position from a flat position to an overhead position.Findings: The optimized shielding gas composition and laser-arc interspacing distance for disk laser-GMA hybrid welding were 80% Ar- 20% CO2 and 2mm, respectively for the bead-on-plate welding. The sound welds could be achieved even in the pipe girth welding, but the proper joint shape should be prepared.Research limitations/implications: The laser-arc hybrid welding was implemented for pipe girth welding as a kind of 3-dimensional laser welding and the process parameters could be optimized according to the various target materials and sizes.Practical implications: The optimized process parameters for the disk laser-arc hybrid welding can extend the application of the laser hybrid welding technology.Originality/value: This research showed the possibility of the disk laser-GMA hybrid welding as new pipe girth welding technique. The behaviour of molten pool and droplet transfer could enhance understanding of the hybrid welding.

  3. Properties of weld deposit for butt weldings of reactor components

    International Nuclear Information System (INIS)

    Mechanical properties of weld deposit type MnNiMo from submerged arc- and manual shielded arc weldings for reactor components, influence of chemical composition and heat treatment condition, proposal for the testing of mechanical properties for weld deposit. (orig.)

  4. Closed-Loop Control System for Friction Stir Welding Retractable Pin Tool

    Science.gov (United States)

    Ding, R. Jeffrey; Romine, Peter L.; Munafo, Paul M. (Technical Monitor)

    2001-01-01

    NASA invention disclosure, NASA Case No. MFS-31413, entitled "System for Controlling the Stirring Pin of a Friction Stir Welding Apparatus", (Patent Pending) authored by Jeff Ding, Dr Peter Romine and Pete Oelgoetz, addresses the precision control of the friction stir welding process. The closed-loop control system automatically adjusts the spinning welding pin, real-time, to maintain a precise penetration ligament (i.e., distance between pin-tip and weld panel backside surface). A specific pin length can be maintained while welding constant thickness or tapered material thickness weld panels. The closed-loop control system provides operator data and information relative to the exact position of the welding pin inside the weld joint. This paper presents the closed-loop RPT control system that operates using the auto-feedback of force signals sensed by the tip and shoulder of the welding pin. Significance: The FSW process can be successfully used in a production environment only if there is a method or technique that informs the FSW operator the precise location of the welding pin inside the weld joint. This is essential for applications in aerospace, automotive, pressure vessel, commercial aircraft and other industries.

  5. Development of LABGENE's steam generators tube to tubesheet welding qualification procedure

    International Nuclear Information System (INIS)

    The welding qualification procedure of LABGENE's Nuclear Electric Generation Laboratory - Steam Generators has special characteristics due to nuclear class 1 requirements, reduced dimensions of the LABGENE's equipment and combination of the materials involved with the tube to tubesheet welding. The welding procedure was performed using an automatic orbital welding machine without material addition. The weld joint was simulated using a sample made of a tube (ext. 12,7 BWG 18 x 90 mm) in SB-163 N08800 material and a plate (48 x 330 x 55 mm) in 20MnMoNi55 material, covered with 8 mm AWS E NiCrFe-3 cladding. For the development of the welding procedure, a lot of welding simulations were performed using machines and special devices designed for the dimensions of the pieces. Procedures related with operating, handling and cleaning conditions, essential to avoid the contamination of the pieces were issued. It was also developed a mixture of gases which contributed for the homogenising of the welding and also to avoid the appearance of cracks and defects on the weld joint. The results obtained with the performed tests fulfilled the requirements of the applied specifications and standards. The welding procedure was developed testing a lot of specimens removed from samples that were representatives of the equipment's tube to tubesheet welding. (author)

  6. Geometric characterization of a circumferential seam by automatic segmentation of digitized radioscopic images

    International Nuclear Information System (INIS)

    The present study deals with the nondestructive control of a circumferential seam by digital radioscopy. A series of images for one complete revolution of the welded component is available. We first resort to a joint approach by simulation and experimentation. This approach allows the detection of the molten zone limits for an initial image. We then develop a segmentation method that permits automatic extraction of the geometric characteristics of the set of images representative of the weld. These measures supply fast and automatic control of the weld quality. Results are shown for real components. (author)

  7. Application of Programmable Logic Controller (PLC) in Control System for Inner and Outer Welding Processes of Irradiation Chamber

    International Nuclear Information System (INIS)

    Inner and outer welding processes of irradiation chamber require reliable human resources so that the welding results will meet the standardized requirements for irradiation with nuclear reactor. The control system of the inner and outer welding processes of the irradiation chamber was made due to limited human resources who are able to weld the irradiation chamber perfectly. The irradiation chamber’s welding is expected to be done automatically by using the system control. The system is created by using Programmable Logic Controller (PLC) which function is to automatically organize the welding processes through the codes attached there in. The system comprises of a control unit which has been tested in a simulation, and then attached in a welding machine unit, and subsequently tested for welding the irradiation chamber. The result of the welding is also tested for its leak using bubble test. As all procedures are well followed in the welding processes, the control system is found to work properly. The welding results which are not optimum are mainly due to imperfect irradiation tubes, such as the lack of symmetry in the tube’s geometry, unclean surface, as well as the condition of the unprecise mechanical part of the tubes. (author)

  8. Prediction of Weld Penetration in FCAW of HSLA steel using Artificial Neural Networks

    International Nuclear Information System (INIS)

    Flux-cored arc welding (FCAW) is a semiautomatic or automatic arc welding process that requires a continuously-fed consumable tubular electrode containing a flux. The main FCAW process parameters affecting the depth of penetration are welding current, arc voltage, nozzle-to-work distance, torch angle and welding speed. Shallow depth of penetration may contribute to failure of a welded structure since penetration determines the stress-carrying capacity of a welded joint. To avoid such occurrences; the welding process parameters influencing the weld penetration must be properly selected to obtain an acceptable weld penetration and hence a high quality joint. Artificial neural networks (ANN), also called neural networks (NN), are computational models used to express complex non-linear relationships between input and output data. In this paper, artificial neural network (ANN) method is used to predict the effects of welding current, arc voltage, nozzle-to-work distance, torch angle and welding speed on weld penetration depth in gas shielded FCAW of a grade of high strength low alloy steel. 32 experimental runs were carried out using the bead-on-plate welding technique. Weld penetrations were measured and on the basis of these 32 sets of experimental data, a feed-forward back-propagation neural network was created. 28 sets of the experiments were used as the training data and the remaining 4 sets were used for the testing phase of the network. The ANN has one hidden layer with eight neurons and is trained after 840 iterations. The comparison between the experimental results and ANN results showed that the trained network could predict the effects of the FCAW process parameters on weld penetration adequately.

  9. Prediction of Weld Penetration in FCAW of HSLA steel using Artificial Neural Networks

    Science.gov (United States)

    Asl, Y. Dadgar; Mostafa, N. B.; Panahizadeh R., V.; Seyedkashi, S. M. H.

    2011-01-01

    Flux-cored arc welding (FCAW) is a semiautomatic or automatic arc welding process that requires a continuously-fed consumable tubular electrode containing a flux. The main FCAW process parameters affecting the depth of penetration are welding current, arc voltage, nozzle-to-work distance, torch angle and welding speed. Shallow depth of penetration may contribute to failure of a welded structure since penetration determines the stress-carrying capacity of a welded joint. To avoid such occurrences; the welding process parameters influencing the weld penetration must be properly selected to obtain an acceptable weld penetration and hence a high quality joint. Artificial neural networks (ANN), also called neural networks (NN), are computational models used to express complex non-linear relationships between input and output data. In this paper, artificial neural network (ANN) method is used to predict the effects of welding current, arc voltage, nozzle-to-work distance, torch angle and welding speed on weld penetration depth in gas shielded FCAW of a grade of high strength low alloy steel. 32 experimental runs were carried out using the bead-on-plate welding technique. Weld penetrations were measured and on the basis of these 32 sets of experimental data, a feed-forward back-propagation neural network was created. 28 sets of the experiments were used as the training data and the remaining 4 sets were used for the testing phase of the network. The ANN has one hidden layer with eight neurons and is trained after 840 iterations. The comparison between the experimental results and ANN results showed that the trained network could predict the effects of the FCAW process parameters on weld penetration adequately.

  10. New welding technologies for car body frame welding

    OpenAIRE

    T. Węgrzyn; J. Piwnik; R. Burdzik; G. Wojnar; D. Hadryś

    2012-01-01

    Purpose: of that paper was analysing main welding process for car body welding. The main reason of it was investigate possibilities of getting varied amount of acicular ferrite (AF) in WMD (weld metal deposit). High amount of acicular ferrite influences positively impact toughness of weld. For optimal amount of AF it is necessary to have optimal chemical composition in WMD. Important role plays especially Ni. There were also tested new welding technology: welding with micro-jet cooling.Design...

  11. Development of temper bead welding by under water laser welding

    International Nuclear Information System (INIS)

    Toshiba has developed temper bead welding by under water laser welding as SCC counter measure for aged components in PWR and BWR nuclear power plants. Temper bead welding by under water laser welding technique recovers toughness of low alloy steel reactor vessel by employing proper the number of cladding layers and their welding conditions. In this report, some evaluation results of material characteristics of temper bead welded low alloy steel are presented. (author)

  12. Peculiarities of weld crystallization in the process of laser welding

    International Nuclear Information System (INIS)

    The effect of the process of laser welding of 08Kh18N10T steel on weld formation and crystallization is investigated. It is shown that at vsub(weld.) >= 40 m/h the lower sinked part of the weldpool stretched along the weld axis is crystallized quickly. Improvement in hot cracking resistance of weld metal in the process of laser welding results from the additional feeding with a liquid metal of the crystallizing part of the weldpool

  13. Survey report on unmanned site welding of austenitic stainless steel pipe and its ultrasonic examination

    International Nuclear Information System (INIS)

    In the field welding of austenitic stainless steel pipings and its non-destructive test in complicated and narrow places, reliable welding method and non-destructive testing method are required, and also, it is desirable to mechanize them (unmanned operation). In this study, the present state of the automatic welding of austenitic stainless steel pipings and ultrasonic flaw detection was investigated through the literatures in Japan and foreign countries. As the result, it was clarified that energetic research has been made recently to mechanize the welding, and though many points are left for future research and development, it is promising. In the ultrasonic flaw detection, many technical problems concerning the detectability of flaws remain at present, but is is expected to become feasible by future systematic research and development. The design of weld joints, the welding method and the remote automatic control of welding operation must be appropriate for guaranteeing the quality of welding, and these points were surveyed. The problems in the ultrasonic flaw detection are the attenuation of ultrasonic waves, the conditions of probes, the mode of wave motion and frequency, and the welding suitable to the ultrasonic flaw detection. (Kako, I.)

  14. Weld energy reduction by using concurrent nondestructive evaluation. Final report

    International Nuclear Information System (INIS)

    In-process inspection of partially completed welds is shown to be feasible and to have the potential of large economic and productivity improvements in certain circumstances. Ultrasonic inspection of the weld and analysis by an automatic pattern-recognition system has a flaw detection rate of 90 to 95% with a false call rate of about 8%. The pattern-recognition system uses cues that human observers use to discriminate between good and flawed weld. The system has the potential to discriminate among types of flaws. An application analysis shows a potential savings of over $21 per foot of weld on two in. thick plates such as used for pressure vessel fabrication. 5 refs., 15 figs., 8 tabs

  15. Film videorecording and image processing systems: structural element welding

    Science.gov (United States)

    Konovalov, Nikolai A.; Veselovsky, Vladimir B.; Kovalenko, Vladimir I.; Lakhno, Nikolay I.; Skorik, Alexander D.; Furmanov, Valeri B.; Polyakov, Gennadiy A.

    1999-06-01

    With the aim of technological process automatization and control for high-frequency welding of different diameters pipes the machine-program complex (APC) was designed. APC gives the opportunity to create the cine- and telerecording of process in production conditions at the mill '159 - 529' of Novomoskovsky Tube Rolling Mill, Ukraine). With the help of APC in real functioning mill conditions the character of flashing zone length changing and the angle of convergence depending on pipe welding speed was investigated, also the zone of jumpers is defined. The comparison of theoretical and experimental data gave an opportunity to define a welding rate which is optimal for the most qualitative values of welded joints in the range of pipe products of mill '159 - 529.'

  16. Challenges to Resistance Welding

    DEFF Research Database (Denmark)

    Song, Quanfeng

    This report originates from the compulsory defense during my Ph.D. study at the Technical University of Denmark. Resistance welding is an old and well-proven technology. Yet the emergence of more and more new materials, new designs, invention off new joining techniques, and more stringent...... requirement in quality have imposed challenges to the resistance welding. More some research and development have to be done to adapt the old technology to the manufacturing industry of the 21st century. In the 1st part of the report, the challenging factors to the resistance welding are reviewed. Numerical...... simulation of resistance welding has been under development for many years. Yet it is no easy to make simulation results reliable and accurate because of the complexity of resistance welding process. In the 2nd part of the report numerical modeling of resistance welding is reviewed, some critical factors to...

  17. Development of a CCTV system for welder training and monitoring of Space Shuttle Main Engine welds

    Science.gov (United States)

    Gordon, S. S.; Flanigan, L. A.; Dyer, G. E.

    1987-01-01

    A Weld Operator's Remote Monitoring System (WORMS) for remote viewing of manual and automatic GTA welds has been developed for use in Space Shuttle Main Engine (SSME) manufacturing. This system utilizes fiberoptics to transmit images from a receiving lens to a small closed-circuit television (CCTV) camera. The camera converts the image to an electronic signal, which is sent to a videotape recorder (VTR) and a monitor. The overall intent of this system is to provide a clearer, more detailed view of welds than is available by direct observation. This system has six primary areas of application: (1) welder training; (2) viewing of joint penetration; (3) viewing visually inaccessible welds; (4) quality control and quality assurance; (5) remote joint tracking and adjustment of variables in machine welds; and (6) welding research and development. This paper describes WORMS and how it applies to each application listed.

  18. EB welding and quality control of nuclear reactor fuel rods at ASEA-ATOM

    International Nuclear Information System (INIS)

    Fourteen years ago ASEA-ATOM chose EB welding for fuel rod plug/tube welds. This choice was made on the basis of 7 years of experience of EB-welding of fuel rods in a pilot plant. The specific reasons were the high quality and the high process yield, which are made possible by the great degree of controlability and reproducibility of this process and because the welds are suitable for QC inspection by an inline ultrasonic method which we developed at the same time. To date ASEA-ATOM has manufactured approximately 600,000 fuel rods with 1,200,000 EB-welds. The results have met expections as regards quality, process yield and service in BWR and PWR reactors. Descriptions are given of the automatic Sciaky EB welding machines, of the ultrasonic inspection equipment and of their process qualification. Some comments are made on quality and process yield

  19. Welding by laser beam

    International Nuclear Information System (INIS)

    A laser which does not require a vacuum and the beam from which can be projected over a distance without loss of power is sited outside a welding zone and the beam projected through a replaceable laser transparent window. The window is designed and shaped to facilitate access of the beam of workpiece items to be welded in containment. Either the workpiece or the laser beam may be moved during welding. (author)

  20. Underwater YAG laser welding technique

    International Nuclear Information System (INIS)

    When planning preventive maintenance of reactor components using welding, it is necessary to consider special environments such as narrow space or difficult accessibility while minimizing exposure to radiation in the reactor pressure vessel. Toshiba has developed an underwater neodymium: yttrium-aluminum-garnet (Nd: YAG) laser welding technique. The features of this welding technique are low-heat-input welding and compact welding machine dimensions for welding in narrow spaces. This paper provides a summary of the new welding technique as a reliable welding technology. (author)

  1. Dual wire welding torch and method

    Science.gov (United States)

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

    2009-04-28

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  2. Electron beam welding

    International Nuclear Information System (INIS)

    Electron-beam equipment is considered along with fixed and mobile electron-beam guns, questions of weld environment, medium and nonvacuum welding, weld-joint designs, tooling, the economics of electron-beam job shops, aspects of safety, quality assurance, and repair. The application of the process in the case of individual materials is discussed, giving attention to aluminum, beryllium, copper, niobium, magnesium, molybdenum, tantalum, titanium, metal alloys, superalloys, and various types of steel. Mechanical-property test results are examined along with the areas of application of electron-beam welding

  3. Robot welding process control

    Science.gov (United States)

    Romine, Peter L.

    1991-01-01

    This final report documents the development and installation of software and hardware for Robotic Welding Process Control. Primary emphasis is on serial communications between the CYRO 750 robotic welder, Heurikon minicomputer running Hunter & Ready VRTX, and an IBM PC/AT, for offline programming and control and closed-loop welding control. The requirements for completion of the implementation of the Rocketdyne weld tracking control are discussed. The procedure for downloading programs from the Intergraph, over the network, is discussed. Conclusions are made on the results of this task, and recommendations are made for efficient implementation of communications, weld process control development, and advanced process control procedures using the Heurikon.

  4. Electric arc welding gun

    Science.gov (United States)

    Luttrell, Edward; Turner, Paul W.

    1978-01-01

    This invention relates to improved apparatus for arc welding an interior joint formed by intersecting tubular members. As an example, the invention is well suited for applications where many similar small-diameter vertical lines are to be welded to a long horizontal header. The improved apparatus includes an arc welding gun having a specially designed welding head which is not only very compact but also produces welds that are essentially free from rolled-over solidified metal. The welding head consists of the upper end of the barrel and a reversely extending electrode holder, or tip, which defines an acute angle with the barrel. As used in the above-mentioned example, the gun is positioned to extend upwardly through the vertical member and the joint to be welded, with its welding head disposed within the horizontal header. Depending on the design of the welding head, the barrel then is either rotated or revolved about the axis of the vertical member to cause the electrode to track the joint.

  5. Manual tube welding torch

    International Nuclear Information System (INIS)

    In a welding torch which fits over a tube intermediate the ends thereof for welding the juncture between the tube and a boss on the back side of a tube plate, a split housing encloses a tungsten electrode, a filler wire duct and a fiber optic bundle arranged to observe the welding process. A shielding gas duct is provided in the housing. A screw is provided for setting electrode/work distance. Difficult remote tube welding operations can be performed with the apparatus. (author)

  6. Welding irradiated stainless steel

    International Nuclear Information System (INIS)

    Conventional welding processes produced severe underbead cracking in irradiated stainless steel containing 1 to 33 appm helium from n,a reactions. A shallow penetration overlay technique was successfully demonstrated for welding irradiated stainless steel. The technique was applied to irradiated 304 stainless steel that contained 10 appm helium. Surface cracking, present in conventional welds made on the same steel at the same and lower helium concentrations, was eliminated. Underbead cracking was minimal compared to conventional welding methods. However, cracking in the irradiated material was greater than in tritium charged and aged material at the same helium concentrations. The overlay technique provides a potential method for repair or modification of irradiated reactor materials

  7. Use of servo controlled weld head for end closure welding

    International Nuclear Information System (INIS)

    In the PHWR fuel fabrication line resistance welding processes are used for joining various zirconium based alloy components to fuel tube of similar material. The quality requirement of these welding processes is very stringent and has to meet all the product requirements. At present these welding processes are being carried out by using standard resistance welding machines. In the resistance welding process in addition to current and time, force is one of the critical and important parameter, which influences the weld quality. At present advanced feed back type fast response medium frequency weld controllers are being used. This has upslope/down slope, constant and repetitive weld pattern selection features makes this critical welding process more reliable. Compared to weld controllers, squeeze force application devices are limited and normally standard high response pneumatic cylinders are used in the welding process. With this type of devices the force is constant during welding process and cannot be varied during welding process as per the material deformation characteristics. Similarly due to non-availability of feed back systems in the squeeze force application systems restricts the accuracy and quality of the welding process. In the present paper the influence of squeeze force pattern on the weld quality using advanced feed back type servo based force control system was studied. Different squeeze forces were used during pre and post weld heat periods along with constant force and compared with the weld quality. (author)

  8. Technology of laser repair welding of nickel superalloy inner flaps of jet engine

    Directory of Open Access Journals (Sweden)

    A. Klimpel

    2011-07-01

    Full Text Available Purpose: of this paper: work out laser welding repair technology of cracked MIG 29 jet engine inner flaps made of cast nickel superalloy ŻS-3DK (ЖС-3ДК, Russian designation.Design/methodology/approach: The study were based on the analysis of laser HPDL powder INCONEL 625 welding of nickel superalloy using wide range of welding parameters to provide highest quality repair welds.Findings: Study of automatic welding technologies GTA, PTA and laser HPDL has shown that just laser welding can provide high quality repair welds. In order to establish the properties of welded joints repair cracks in the inner flap HPDL laser, studied the hardness, mechanical properties and erosive wear resistance.Research limitations/implications: It was found that only laser HPDL welding can provide high quality repair welds.Practical implications: The technology can be applied for repair cracked MIG 29 jet engine inner flaps.Originality/value: Repairing cracked MIG 29 jet engine inner flaps.

  9. A Review: Welding Of Dissimilar Metal Alloys by Laser Beam Welding & Friction Stir Welding Techniques

    Directory of Open Access Journals (Sweden)

    Ms. Deepika Harwani

    2014-12-01

    Full Text Available Welding of dissimilar metals has attracted attention of the researchers worldwide, owing to its many advantages and challenges. There is no denial in the fact that dissimilar welded joints offer more flexibility in the design and production of the commercial and industrial components. Many welding techniques have been analyzed to join dissimilar metal combinations. The objective of this paper is to review two such techniques – Laser welding and Friction stir welding. Laser beam welding, a high power density and low energy-input process, employs a laser beam to produce welds of dissimilar materials. Friction stir welding, a solid-state joining process, is also successfully used in dissimilar welding applications like aerospace and ship building industries. This paper summarizes the trends and advances of these two welding processes in the field of dissimilar welding. Future aspects of the study are also discussed.

  10. Welding machine and welding process for nuclear fuel assembly structures

    International Nuclear Information System (INIS)

    The welding device comprises a mounting jig which receives the guide tubes and the assembly supporting structures in the desired spatial orientation. It also comprises a welding head which can travel on rails along the length of the guide tubes and has at least a welding spring chuck movable in two axes and rotatable relative to the welding machine; the spring chuck can pass between two adjacent tube rows and takes a tubes where a weld is necessary. The welding spring chuck can apply spot-welding pulses. This is used for the assembly of guide tubes and bundles for water-cooled nuclear reactors

  11. Laser Welding in Space

    Science.gov (United States)

    Workman, Gary L.; Kaukler, William F.

    1989-01-01

    Solidification type welding process experiments in conditions of microgravity were performed. The role of convection in such phenomena was examined and convective effects in the small volumes obtained in the laser weld zone were observed. Heat transfer within the weld was affected by acceleration level as indicated by the resulting microstructure changes in low gravity. All experiments were performed such that both high and low gravity welds occurred along the same weld beam, allowing the effects of gravity alone to be examined. Results indicate that laser welding in a space environment is feasible and can be safely performed IVA or EVA. Development of the hardware to perform the experiment in a Hitchhiker-g platform is recomended as the next step. This experiment provides NASA with a capable technology for welding needs in space. The resources required to perform this experiment aboard a Shuttle Hitchhiker-pallet are assessed. Over the four year period 1991 to 1994, it is recommended that the task will require 13.6 manyears and $914,900. In addition to demonstrating the technology and ferreting out the problems encountered, it is suggested that NASA will also have a useful laser materials processing facility for working with both the scientific and the engineering aspects of materials processing in space. Several concepts are also included for long-term optimization of available solar power through solar pumping solid state lasers directly for welding power.

  12. Laser welding in space

    International Nuclear Information System (INIS)

    This paper reports on the design and construction, as well as typical results from performing low gravity laser welding experiments on NASA's KC-135 aircraft flying parabolic maneuvers to simulate low gravity. Results of the experiments are reported and some new concepts regarding the implementation of laser technology suitable for laser welding in space are presented

  13. Simulation of welding

    Institute of Scientific and Technical Information of China (English)

    Chuan-Song WU; Michael RETHMEIER; Christopher SCHWENK

    2011-01-01

    @@ Welding has become the most important materials processing technology in manufacturing, and has critical effects on the quality, reliability and life of products as well as production cost, efficiency and response speed to market.As various kinds of high performance metallic materials are widely used in engineering, there are more demands in manufacturing industry for advanced welding technology.

  14. Sorting Titanium Welding Rods

    Science.gov (United States)

    Ross, W. D., Jr.; Brown, R. L.

    1985-01-01

    Three types of titanium welding wires identified by their resistance to current flow. Welding-wire tester quickly identifies unknown titaniumalloy wire by touching wire with test probe, and comparing meter response with standard response. Before touching wire, tip of test probe dipped into an electrolyte.

  15. Welding Tubes In Place

    Science.gov (United States)

    Meredith, R.

    1984-01-01

    Special welding equipment joins metal tubes that carry pressurized cyrogenic fluids. Equipment small enough to be used in confined spaces in which such tubes often mounted. Welded joints lighter in weight and more leak-proof than joints made with mechanical fittings.

  16. Method for welding beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, R.D.; Smith, F.M.; O`Leary, R.F.

    1995-12-31

    A method is provided for joining beryllium pieces which comprises: depositing aluminum alloy on at least one beryllium surface; contacting that beryllium surface with at least one other beryllium surface; and welding the aluminum alloy coated beryllium surfaces together. The aluminum alloy may be deposited on the beryllium using gas metal arc welding. The aluminum alloy coated beryllium surfaces may be subjected to elevated temperatures and pressures to reduce porosity before welding the pieces together. The aluminum alloy coated beryllium surfaces may be machined into a desired welding joint configuration before welding. The beryllium may be an alloy of beryllium or a beryllium compound. The aluminum alloy may comprise aluminum and silicon. Beryllium parts made using this method can be used as structural components in aircraft, satellites and space applications.

  17. Method for welding beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, R.D.; Smith, F.M.; O`Leary, R.F.

    1997-04-01

    A method is provided for joining beryllium pieces which comprises: depositing aluminum alloy on at least one beryllium surface; contacting that beryllium surface with at least one other beryllium surface; and welding the aluminum alloy coated beryllium surfaces together. The aluminum alloy may be deposited on the beryllium using gas metal arc welding. The aluminum alloy coated beryllium surfaces may be subjected to elevated temperatures and pressures to reduce porosity before welding the pieces together. The aluminum alloy coated beryllium surfaces may be machined into a desired welding joint configuration before welding. The beryllium may be an alloy of beryllium or a beryllium compound. The aluminum alloy may comprise aluminum and silicon. 9 figs.

  18. Orbital welding technique; Orbitalschweisstechnik

    Energy Technology Data Exchange (ETDEWEB)

    Hoeschen, W. [Kraftanlagen Nukleartechnik GmbH, Heidelberg (Germany)

    2003-07-01

    The TIG (Tungsten-inert gas) orbital welding technique is applied in all areas of pipe welding. The process is mainly used for austenitic and ferritic materials but also for materials like aluminium, nickel, and titanium alloys are commonly welded according to this technique. Thin-walled as well as thick-walled pipes are welded economically. The application of orbital welding is of particular interest in the area of maintenance of thick-walled pipes that is described in this article. (orig.) [German] Die praktische Anwendung des Wolfram-Inertgas-(WIG-)Orbitalschweissverfahrens erfolgt in allen Sparten des Rohrleitungsbaues. Vorwiegend wird das Verfahren an austenitischen und ferritischen Werkstoffen eingesetzt. Aber auch andere Werkstoffe, wie Aluminium, Nickel- und Titanlegierungen, sind gaengige Praxis. Dabei werden sowohl duenn- als auch dickwandige Rohre wirtschaftlich verschweisst. In der Instandhaltung ist die Anwendung der Orbitaltechnik fuer dickwandige Rohre von besonderem Interesse und wird hier beschrieben. (orig.)

  19. Vacuum welding of metals

    International Nuclear Information System (INIS)

    This new welding process has been developed by the Commissariat a l'Energie Atomique (CEA) in France. The edges of the work-pieces are melted by the impact of an electron beam produced by an electron gun. Welding is carried out in a vacuum of 10-4 to 10-8 mm of mercury. The welding machine consists, diagrammatically, of: a) a metal enclosure in which a vacuum is produced; b) a cathode for electron emission, a high-voltage generator for accelerating these electrons, a focusing device; c) a mechanical device for moving (rotating) the work-piece. Advantages of the process: 1) possible welding of highly oxidizable metals (e.g. zirconium); 2) fabrication of high-vacuum-sealed metal containers; 3) production of very deeply penetrated welds. Therefore, this new process is particularly advantageous for atomic power applications, the fabrication of electron tubes and, more generally, for all industries in which very special metals are used. (author)

  20. Argon Welding Inside A Workpiece

    Science.gov (United States)

    Morgan, Gene E.

    1988-01-01

    Canopies convert large hollow workpiece into inert-gas welding chamber. Large manifold serves welding chamber for attachment of liner parts in argon atmosphere. Every crevice, opening and passageway provided with argon-rich environment. Weld defects and oxidation dramatically reduced; also welding time reduced.

  1. Laser forming and welding processes

    CERN Document Server

    Yilbas, Bekir Sami; Shuja, Shahzada Zaman

    2013-01-01

    This book introduces model studies and experimental results associated with laser forming and welding such as laser induced bending, welding of sheet metals, and related practical applications. The book provides insight into the physical processes involved with laser forming and welding. The analytical study covers the formulation of laser induced bending while the model study demonstrates the simulation of bending and welding processes using the finite element method. Analytical and numerical solutions for laser forming and welding problems are provided.

  2. Computer vision based end cap weld quality inspection system

    International Nuclear Information System (INIS)

    This paper describes a weld quality inspection system that has been developed for QA(F), NFC to evaluate the PHWR end cap welds. The system consists of a trinocular microscope with a video camera connected through a video reduction lens, PCI video frame grabber and PC based acquisition and analysis software. The software developed in the VC++ under windows operating system calculates the non-fusion percentage for the weld specimens in two different modes of computing i.e. Indian welding inspection method and Canadian welding inspection method. The software uses image processing and analysis algorithms to automatically identify the lack of fusion lines as per user supplied parameters for a specific set-up of the system. The lack of fusion lines and the region of interest that was used for computation are marked on the image and can be saved for future reference. GUI for user interaction to delete or add non-fusion lines is also provided. A report generation module has been integrated with the analysis software as per user requirements. Reports are generated for the end cap welding performance including machine set up, machine qualification and operator qualification information. (author)

  3. Achieving cost savings with innovative welding and examination techniques

    International Nuclear Information System (INIS)

    In an effort to maximize quality and production in both field and shop fabrication while minimizing cost, Fluor has assessed new and innovative welding and examination technologies. Welding applications, power sources, arc transfer modes, and shielding gas mixtures using various semi-automatic processes were compared. The strategies for the selection of these welding variables, as well as the successful application of a modified short-circuiting gas metal arc welding process to carbon, alloy, and stainless steels are discussed. The optimized process combination can achieve three times the deposition rate and one-tenth of the repair rate commonly obtained with traditional processes. In weldment examinations, a modified phased array ultrasonic technique is presented. As an alternate for radiography, phased array technology allows for 10 times lower inspection times and lends itself to an ideal weld-and-check methodology. Additional cost savings and further, productivity improvements have been achieved by combining these novel welding and examination techniques. This technology has demonstrated itself with a supporting track record on several major construction projects in North America

  4. Elucidation of laser welding phenomena and factors affecting weld penetration and welding defects

    Science.gov (United States)

    Katayama, Seiji; Kawahito, Yousuke; Mizutani, Masami

    The behavior and effect of a plasma plume on the weld penetration are greatly different between CO2 laser welding and YAG, disk or fiber laser welding. The effects of the power and the power density on the weld penetration are elucidated. Spattering leading to the formation of underfilled weld beads is controlled by inclining the laser beam. Porosity is formed from bubbles generated from the tip of the keyhole at low welding speed or from the middle part of the keyhole at high laser power density. Cracking easily occurs in pulsed spot welding of aluminum alloys.

  5. Welding processes handbook

    CERN Document Server

    Weman, Klas

    2003-01-01

    Deals with the main commercially significant and commonly used welding processes. This title takes the student or novice welder through the individual steps involved in each process in an easily understood way. It covers many of the requirements referred to in European Standards including EN719, EN 729, EN 729 and EN 287.$bWelding processes handbook is a concise, explanatory guide to the main commercially significant and commonly-used welding processes. It takes the novice welder or student through the individual steps involved in each process in a clear and easily understood way. It is intended to provide an up-to-date reference to the major applications of welding as they are used in industry. The contents have been arranged so that it can be used as a textbook for European welding courses in accordance with guidelines from the European Welding Federation. Welding processes and equipment necessary for each process are described so that they can be applied to all instruction levels required by the EWF and th...

  6. A Review: Welding Of Dissimilar Metal Alloys by Laser Beam Welding & Friction Stir Welding Techniques

    OpenAIRE

    Ms. Deepika Harwani; Mr. Kapil Banker

    2014-01-01

    Welding of dissimilar metals has attracted attention of the researchers worldwide, owing to its many advantages and challenges. There is no denial in the fact that dissimilar welded joints offer more flexibility in the design and production of the commercial and industrial components. Many welding techniques have been analyzed to join dissimilar metal combinations. The objective of this paper is to review two such techniques – Laser welding and Friction stir welding. Laser beam we...

  7. Low-hydrogen Electrode Root Welding Technology of X80 Pipeline Steel%X80管线钢低氢焊条根焊技术

    Institute of Scientific and Technical Information of China (English)

    薛慧; 孔繁荣

    2015-01-01

    目前我国大直径长输管道大部分采用X80管线钢, X80钢根焊道的焊接常采用管道全位置自动焊、 STT和RMD半自动焊、钨极氩弧焊以及焊条电弧焊等工艺。管道全位置自动焊设备昂贵、适应性差。 STT和RMD半自动焊焊接时灵活性较差,必须严格防风措施。钨极氩弧焊的抗风能力差且焊接效率太低。低氢焊条电弧焊虽操作难度大且焊接效率不高,但灵活性强、焊接接头力学性能好且设备简单,适应于返修、连头和不良地段的焊接。详细介绍了X80管线钢低氢焊条根焊焊道的焊前准备、焊接操作技术及焊接工艺参数。%At present, X80 pipeline steel mostly was used in large diameter long-distance pipeline in China. In X80 steel root welding, it usually adopts all position automatic welding, STT and RMD semi-automatic welding, tungsten argon arc welding, shielded metal arc welding, etc. The equipment of pipeline all position automatic welding is expensive, poor adaptability;windproof measures must be strictly controlled in STT and RMD semi-automatic welding;The poor ability to resist the wind for tungsten argon arc welding and its welding efficiency is too low. Although high operation difficulty and low welding efficiency for low hydrogen electrode arc welding, but it is with good flexibility and simple equipment, the mechanical properties of welded joint are good, suitable for welding repair, butt welding and welding in bad location. In this article, it detailedly introduced preparation before welding, welding technology and welding parameters for X80 pipeline steel low-hydrogen electrode root welding bead.

  8. Thermal stir welding process

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2012-01-01

    A welding method is provided for forming a weld joint between first and second elements of a workpiece. The method includes heating the first and second elements to form an interface of material in a plasticized or melted state interface between the elements. The interface material is then allowed to cool to a plasticized state if previously in a melted state. The interface material, while in the plasticized state, is then mixed, for example, using a grinding/extruding process, to remove any dendritic-type weld microstructures introduced into the interface material during the heating process.

  9. Thermal stir welding apparatus

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2011-01-01

    A welding method and apparatus are provided for forming a weld joint between first and second elements of a workpiece. The method includes heating the first and second elements to form an interface of material in a plasticized or melted state interface between the elements. The interface material is then allowed to cool to a plasticized state if previously in a melted state. The interface material, while in the plasticized state, is then mixed, for example, using a grinding/extruding process, to remove any dendritic-type weld microstructures introduced into the interface material during the heating process.

  10. Welding Robot Applications in Shipbuilding Industry: Off-Line Programming, Virtual Reality Simulation, and Open Architecture

    OpenAIRE

    Kim, Chang-Sei; Hong, Keum-Shik; Han, Yong-Sub

    2006-01-01

    This chapter described the welding robot system in a shipbuilding industry and the PCbased off-line programming system. The welding robot system is very helpful not only to increase productivity but also to solve worker's health problem. The developed off-line programming system provides a robot simulation, a block arrangement simulation, optimal robot traveling path generation, and automatic robot program generation. Because graphic environments are made in the VRML, developed off-line progr...

  11. Hybrid laser-arc welding

    DEFF Research Database (Denmark)

    Hybrid laser-arc welding (HLAW) is a combination of laser welding with arc welding that overcomes many of the shortfalls of both processes. This important book gives a comprehensive account of hybrid laser-arc welding technology and applications. The first part of the book reviews...... the characteristics of the process, including the properties of joints produced by hybrid laser-arc welding and ways of assessing weld quality. Part II discusses applications of the process to such metals as magnesium alloys, aluminium and steel as well as the use of hybrid laser-arc welding in such sectors as ship...... building and the automotive industry. With its distinguished editor and international team of contributors, Hybrid laser-arc welding, will be a valuable source of reference for all those using this important welding technology. Professor Flemming Ove Olsen works in the Department of Manufacturing...

  12. 锅炉筒体内环焊缝埋弧自动焊机%Research on submerged arc welding machine designed on inner circular welding for the boiler

    Institute of Scientific and Technical Information of China (English)

    沙玉章; 张晓明; 邢铁刚

    2011-01-01

    普通的埋孤焊接小车和焊接操作架无法进入锅炉筒体内实施焊接,锅炉筒体组合最后一道内环焊缝的焊接一直采用手工焊接.研发的锅炉筒体内环焊缝埋弧自动焊机的核心部分为焊接小车、焊缝跟踪器和焊枪调整机构,焊接电源、筒体转胎和焊丝盘为常规设备.其创新之处在于:一是焊接小车体积小、质量轻,一个工人即可将其搬出、入筒体人孔;二是焊接小车配置了功能完善的机械式焊缝跟踪器,保证焊接小车始终准确可靠地与焊缝平行等距行走,即保证在焊接过程中焊枪始终不偏离焊缝.实现了焊缝的优质高效自动化焊接,焊缝探伤合格率达98%以上,焊缝宽度均匀,表面光滑美观,填补了此项焊接专机在国内的空白.%Because ordinary submerged arc welding carriage and welding operation frame could not go into the boiler the cylinder for inner welding,the final inner welding seam has been using manual welding.The core part of developed boiler cylindrical shell inner weld seam submerged arc welder are the welding carriage,seam tracking device and welding torch regulator,the welding power source,barrel turn tire and wire reel are conventional equipments.The innovation of this research are those:First,welding carriage has small size, lightweight, only one worker can move into and out of the cylinder manhole; Second, the welding carriage is configured a fully functioning mechanical welding seam tracker,ensuring that the car always reliable way and weld parallel isometric moving, namely that welding torch always not deviating from the welding seam in the welding process.Realize the welding line of automatic welding quality and efficient,weld qualified rate above 98%,and the weld width uniformity,the surface is smooth and beautiful,fill the welding machine in domestic blank.

  13. Welding of tailored blanks of different materials

    OpenAIRE

    Suban, Marjan; Tušek, Janez; Kampuš, Zlatko

    2015-01-01

    This paper treats welding of tailored blanks made of different materials. In general, fusion welding and welding with pressure, practically without fusion, are described. Fusion welding may be carried out with or without the addition of filler material. In Section 3, general characteristics of tailored blanks are described. In Section 4, MIG welding and laser welding of austenitic stainless steel with ferrite non-stainless steel are described. After welding, hardness of the welded joints was ...

  14. Optimising residual stresses at a repair in a steam header to tubeplate weld

    International Nuclear Information System (INIS)

    Following the discovery of incorrect weld metal in the steam side shell to tubeplate weld in a type 316H stainless steel superheater steam header, a repair strategy had to be determined. The strategy adopted was to remove the incorrect weld material, which extended around the full circumference, by machining from the inside of the header, followed by rewelding from the inside using an automatic welding process and localised post-weld heat treatment. Due to concern over potential reheat cracking of the repair after return to service, a considerable amount of residual stress modelling was carried out to support the development and optimisation of a successful repair and heat treatment strategy and thus underwrite the safety case for return to service

  15. A creative design of robotic visual tracking system in tailed welded blanks based on TRIZ

    Institute of Scientific and Technical Information of China (English)

    Zhang Lei; Zhao Mingyang; Zou Yuanyuan; Zhao Lihua

    2006-01-01

    According to the main tools of TRIZ, the theory of inventive problem solving, a new flowchart of the product conceptual design process to solve contradiction in TRIZ is proposed. In order to realize autonomous moving and automatic weld seam tracking for welding robot in Tailed Welded Blanks, a creative design of robotic visual tracking system based on CMOS has been developed by using the flowchart. The new system is not only used to inspect the workpiece ahead of a welding torch and measure the joint orientation and lateral deviation caused by curvature or discontinuity in the joint part, but also to record and measure the image size of the weld pool. Moreover, the hardware and software components are discussed in brief.

  16. Multispot fiber laser welding

    DEFF Research Database (Denmark)

    Schutt Hansen, Klaus

    This dissertation presents work and results achieved in the field of multi beam fiber laser welding. The project has had a practical approach, in which simulations and modelling have been kept at a minimum. Different methods to produce spot patterns with high power single mode fiber lasers have...... been examined and evaluated. It is found that both diamond turned DOE’s in zinc sulphide and multilevel etched DOE’s (Diffractive Optical Elements) in fused silica have a good performance. Welding with multiple beams in a butt joint configuration has been tested. Results are presented, showing it has...... in the weld causing expulsion of the melt pool. Trailing beams were applied to melt additional material and ensure a melt pool. The method showed good results for increasing tolerances to impurities and reduction of scrapped parts from blowouts during laser welding....

  17. Friction stir welding tool

    Science.gov (United States)

    Tolle; Charles R. , Clark; Denis E. , Barnes; Timothy A.

    2008-04-15

    A friction stir welding tool is described and which includes a shank portion; a shoulder portion which is releasably engageable with the shank portion; and a pin which is releasably engageable with the shoulder portion.

  18. Welding Qualification Sharing

    International Nuclear Information System (INIS)

    ASME Section IX, 'Welding Qualifications', requires that each organization qualify its own welders and welding procedures. Qualification responsibility cannot be subcontracted, and qualifications administered by one organization cannot be transferred to another organization. This requirement has become the subject of close scrutiny as the demand for efficiency, particularly among nuclear plant owners, has increased. Two recent Code Cases change procedure and performance qualification requirements for the better. The first, N-573, enables nuclear plant owners to share welding procedure qualifications. The second, N-600, enables nuclear plant owners to share welder performance qualifications. Several owners have reduced costs using N-573. N-600, because it is relatively new, has not yet been implemented. Its potential for cost savings, though, is equivalent to that afforded by N-573. This paper discusses ASME Section IX's procedure and performance qualification philosophy, assesses that philosophy in light of today's welding environment, and discusses implementation of Code Cases N-573 and N-600. (authors)

  19. Laser welding of venotomies.

    Science.gov (United States)

    White, R A; Abergel, R P; Klein, S R; Kopchok, G; Dwyer, R M; Uitto, J

    1986-08-01

    We investigated the histologic and biochemical effects of carbon dioxide and neodymium (Nd)-YAG laser welding on the healing of venotomies. Ten canine femoral venotomies 2 cm in length were approximated and welded with 10 600-nm wavelength, 1-W power over 20 to 25 s for CO2 laser, and 1060-nm wavelength, 1-W power over 30 to 40 s for Nd-YAG laser. On removal at one to three weeks, all veins (4/4 welded by CO2 and 6/6 by Nd-YAG) were patent without hematomas. Histologic and biochemical analyses of the venous tissues demonstrated active healing at the venotomy sites. We conclude that the CO2 and Nd-YAG lasers can be used successfully to weld venotomies and may provide an alternative to conventional suture techniques for repair of vascular lesions. PMID:3089196

  20. Magnetic Pulse Welding Technology

    Directory of Open Access Journals (Sweden)

    Ahmad K. Jassim

    2011-12-01

    Full Text Available In this paper, the benefits of using Magnetic Pulse machine which is belong to Non-conventional machine instead of conventional machine. Magnetic Pulse Technology is used for joining dissimilar metals, and for forming and cutting metals. It is a non contact technique. Magnetic field is used to generate impact magnetic pressure for welding and forming the work piece by converted the electrical energy to mechanical energy. It is enable us to design previously not possible by welding dissimilar materials and allowing to welds light and stronger materials together. It can be used to weld metallic with non metallic materials to created mechanical lock on ceramics, polymers, rubbers and composites. It is green process; there is no heat, no radiation, no gas, no smoke and sparks, therefore the emissions are negligible.

  1. Welding of refractory alloys

    International Nuclear Information System (INIS)

    This review primarily summarizes welding evaluations supported by NASA-Lewis Research Center in the 1960s. A literature search run in preparation for this review indicates that more recent work is modest by comparison. Hence, this review restates these accomplishments briefly and addresses opportunities which have evolved in welding technology (such as lasers) in the intervening decade. Emphasis in this review is given to tantalum- and niobium-base alloys. Considerable work was also done to assure that a consistent comparison was made with tungsten. A wide variety of candidate alloys derived primarily from developments directed at aircraft propulsion applications were available. Early efforts by NASA were directed at screening studies to select promising structural alloys for the space power application. This objective required fine tuning of welding procedures, e.g., the demonstration of stringent standards for control of welding atmosphere to assure good corrosion resistance in liquid alkali metals. 16 figures, 6 tables

  2. An intelligent real time 3D vision system for robotic welding tasks

    OpenAIRE

    Rodrigues, Marcos; Kormann, Mariza; Schuhler, C; Tomek, P

    2013-01-01

    MARWIN is a top-level robot control system that has been designed for automatic robot welding tasks. It extracts welding parameters and calculates robot trajectories directly from CAD models which are then verified by real-time 3D scanning and registration. MARWIN's 3D computer vision provides a user-centred robot environment in which a task is specified by the user by simply confirming and/or adjusting suggested parameters and welding sequences. The focus of this paper is on describing a mat...

  3. Numerical simulation of welding

    DEFF Research Database (Denmark)

    Hansen, Jan Langkjær; Thorborg, Jesper

    , good predictions of the thermal field are obtained. This has been verified with experiments. The significance of the right fitting of the model to the topical welding process must be emphasized. With a mechanical model in ABAQUS based on a thermal model as described, distributions of both transient...... welding process. Various circumstances are process dependent and require not only knowledge of the process in practice butalso a thorough experience with the numerical modelling of the problem....

  4. Magnetic Pulse Welding Technology

    OpenAIRE

    Ahmad K. Jassim

    2011-01-01

    In this paper, the benefits of using Magnetic Pulse machine which is belong to Non-conventional machine instead of conventional machine. Magnetic Pulse Technology is used for joining dissimilar metals, and for forming and cutting metals. It is a non contact technique. Magnetic field is used to generate impact magnetic pressure for welding and forming the work piece by converted the electrical energy to mechanical energy. It is enable us to design previously not possible by weld...

  5. Friction Stir Weld Tools

    Science.gov (United States)

    Carter, Robert W. (Inventor); Payton, Lewis N. (Inventor)

    2007-01-01

    A friction stir weld tool sleeve is supported by an underlying support pin. The pin material is preferably selected for toughness and fracture characteristics. The pin sleeve preferably has a geometry which employs the use of an interrupted thread, a plurality of flutes and/or eccentric path to provide greater flow through. Paddles have been found to assist in imparting friction and directing plastic metal during the welding process.

  6. SORPAS – The Professional Software for Simulation of Resistance Welding

    DEFF Research Database (Denmark)

    Zhang, Wenqi

    2002-01-01

    Based on long time engineering research and dedicated collaborations with industry, the professional welding software, SORPAS, has been developed for simulation of resistance projection and spot welding processes applying the powerful finite element method (FEM). In order to make the software...... and easily operate and utilize the software. With the user-friendly facilities for flexible geometric design of work pieces and electrodes as well as process parameter settings similar to real machine parameter settings, the software has been readily applied in industry for supporting product development...... directly usable by engineers and technicians in industry, all of the important parameters in resistance welding are considered and automatically implemented into the software. With the specially designed graphic user interface for Windows, engineers (even without prior knowledge of FEM) can quickly learn...

  7. Laser Welding Of Finned Tubes Made Of Austenitic Steels

    Directory of Open Access Journals (Sweden)

    Stolecki M.

    2015-09-01

    Full Text Available This paper describes the technology of welding of finned tubes made of the X5CrNi1810 (1.4301 austenitic steel, developed at Energoinstal SA, allowing one to get high quality joints that meet the requirements of the classification societies (PN-EN 15614, and at the same time to significantly reduce the manufacturing costs. The authors described an automatic technological line equipped with a Trumph disc laser and a tube production technological process. To assess the quality of the joints, one performed metallographic examinations, hardness measurements and a technological attempt to rupture the fin. Analysis of the results proved that the laser-welded finned tubes were performed correctly and that the welded joints had shown no imperfections.

  8. Welding unit - Metallurgical Research Department

    International Nuclear Information System (INIS)

    This report reviews the activities of the Metallurgical Research Department's Welding Unit during 1984. Major research programs during the year included nuclear waste container welding, pulsed-current gas-metal-arc welding procedure development, welding automation and robotics, and repair welding technology, particularly temperbead. Smaller research projects, and the substantial amount of field support and service work performed in 1984, are also summarized. Reports issued by the Welding Unit, as well as externally published papers and presentations are listed. Finally, the proposed activities and objectives for the Unit's 1985 work program are outlined, with particular reference to the major research areas carrying on from 1984

  9. Mechanized and robotized welding in shipbuilding; Zosen ni okeru yosetsu no jidoka robot ka

    Energy Technology Data Exchange (ETDEWEB)

    Kanda, Y. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1997-12-01

    Large-scale ships such as VLCC are built at the Kure No.1 Works of IHI (Ishikawajima-Harima Heavy Industry). This paper introduces current status of mechanized and robotized welding at the works. For the sub-assembly with short weld length and horizontal fillet, simplified automatic welders are used in which mag-welding method using CO2 is adopted. The frequent wound welding of member ends can be automatically conducted using welders developed by IHI. In the large-scale assembly processes, remarkable rationalization and highly accurate assembly of flat plate welding have been promoted. Tankers, container ships, and bulk carriers can be treated at the same time. Teaching times of welding robots can be greatly reduced by a technique called parametric treatment. In the future, it is essential to enhance the accuracy of members by introducing the laser cutting during machining processes. Completely self-type mechanization is required as well as large-output laser welding and sensor technology. 3 refs., 12 figs., 2 tabs.

  10. Finding Optimum Focal Point Position with Neural Networks in CO2 Laser Welding

    DEFF Research Database (Denmark)

    Gong, Hui; Olsen, Flemming Ove

    1997-01-01

    CO2 lasers are increasingly being utilized for quality welding in production. Considering the high equipment cost, the start-up time and set-up time should be minimized. Ideally the parameters should be set up and optimized more or less automatically. In this article neural networks are designed...... to optimize the focal point position, one of the most critical parameters in laser welding. The feasibility to automatically optimize the focal point position is analyzed. Preliminary tests demonstrate that neural networks can be used to optimize the focal point position with good accuracy in CW CO2 laser...

  11. Modeling and NDT evaluation of bearing pad weld strength in PHWR fuel tubes

    International Nuclear Information System (INIS)

    A PHWR fuel consists of a cluster of fuel elements whose ends are welded by endplate to form a bundle. The fuel pins consists of UO2 pellets loaded inside 0.38 mm Zirconium alloy tubes. The fuel bundle has to travel horizontally over 40 meters inside the reactor. In order to prevent damage to fuel tube, three bearing pads are welded to the outer fuel elements. These bearing pads provide bearing surfaces while charging and discharging the bundle in reactor. It also facilitate proper coolant flow. Bearing Pads are welded to the clad tubes by Resistance welding. These welds have to meet minimum shear strength criteria for meeting their purpose in the reactor. At present, the strength of these welds is tested using Automatic strength testing machine on sampling basis. Since the present practice of strength testing is destructive in nature, it cannot be used on actual production welds. In order to overcome this problem a Non destructive Testing method has been developed using numerical modeling and Ultrasonics to predict the weld strength. Area of contact between bearing pad and the fuel tube essentially determines the shear strength of the material. The area of contact was determined by using C-scan ultrasonic flaw detection system by using spherically focused immersion probe (frequency 25 MHz and focal spot dia 0.5mm). The normal beam and C scan images were obtained for all welds by moving the probe over the weld area by 0.1mm increment. The images obtained processed using MATLAB software to carry out measurement of the weld zone. A Micro-Mechanical model was developed to obtain correlation between weld nugget area and weld strength. Finite element analysis was carried out using ANSYS software to predict the weld strength for a given weld area of contact. Weld samples with different welding parameters to give strength values over a wide range. The above developed model was used to predict strength values. The results obtained were compared with the actual strength

  12. Fluid Flow Phenomena during Welding

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Wei [ORNL

    2011-01-01

    MOLTEN WELD POOLS are dynamic. Liquid in the weld pool in acted on by several strong forces, which can result in high-velocity fluid motion. Fluid flow velocities exceeding 1 m/s (3.3 ft/s) have been observed in gas tungsten arc (GTA) welds under ordinary welding conditions, and higher velocities have been measured in submerged arc welds. Fluid flow is important because it affects weld shape and is related to the formation of a variety of weld defects. Moving liquid transports heat and often dominates heat transport in the weld pool. Because heat transport by mass flow depends on the direction and speed of fluid motion, weld pool shape can differ dramatically from that predicted by conductive heat flow. Temperature gradients are also altered by fluid flow, which can affect weld microstructure. A number of defects in GTA welds have been attributed to fluid flow or changes in fluid flow, including lack of penetration, top bead roughness, humped beads, finger penetration, and undercutting. Instabilities in the liquid film around the keyhole in electron beam and laser welds are responsible for the uneven penetration (spiking) characteristic of these types of welds.

  13. Classification of welding defects in metals using artificial neural network

    International Nuclear Information System (INIS)

    This paper discusses the automatic recognition of the return signal with metal welding defects such as cracks, slag and porosity. Normal samples are used as reference benchmarks. A total of 12 features were used to characterize the types of damages. Classification process is done by using feed forward artificial neural network back propagation. The process of acquisition and data processing were carried out fully automatically. There are artificial neural classification processes using MATLAB software has been successfully undertaken in which the system can identify defects that are owned by more than 90% accuracy. (author)

  14. WELD FORMATION CONTROL AT ELECTRON BEAM WELDING WITH BEAM OSCILLATIONS

    OpenAIRE

    Trushnikov, Dmitriy; Koleva, Elena; Mladenov, Georgy; Shcherbakov, A.

    2014-01-01

    Electron beam welding is used extensively to produce essential machine parts. The control of the basic beam parameters beam power or beam current at constant accelerating voltage, welding speed, current of focusing lens and distance between electron gun and welded sample surface is not enough to obtain at most of the regimes sound welds. Control of the focus position using analysis of the high frequency component of the current, collected by plasma, at periodic interactions on the beam (the o...

  15. Constant speed control for complex cross-section welding using robot based on angle self-test

    Science.gov (United States)

    Xue, Long; Zou, Yong; Huang, Jiqiang; Huang, Junfen; Tao, Xinghua; Hu, Yanfeng

    2014-03-01

    Expandable profile liner(EPL) is a promising new oil well casing cementing technique, and welding is a major EPLs connection technology. Connection of EPL is still in the stage of manual welding so far, automatic welding technology is a hotspot of EPL which is one of the key technologies to be solved. A robot for automatic welding of "8" type EPL is studied. Four quadrants of mathematical equations of the 8-shaped cross-section track of EPL, consisting of multiple arcs, are established. Mechanism program for complex cross-section welding of EPL based on angle detection is proposed according to characteristics of small size, small valleys, and large forming errors, etc. A welding velocity vector control model is established by linkage control of a welding vehicle, a small driven actuator, and a height tracking mechanism. A constant speed control model based on an angle and symmetrical analysis model of rectangular coordinate system for EPL is built. Constraint conditions of constant speed control between each section are analyzed with 4 sections in first quadrant as an example, and cooperation work mechanism of the welding vehicle and the small tracking actuator is established based on pressure detection. The constant speed control model using angle self-test can be used to avoid the need for a precise mathematical model for tracking control and to adapt manufacture and installation deviation of EPL workpiece. The model is able to solve constant speed and trajectory tracking problems of EPL cross-section welding. EPL seams welded by the studied robot are good in appearance, and non-destructive testing(NDT) shows the seams are good in quality with no welding defects. Bulge tests show that the maximum pressure of welded EPL is 35 MPa, which can fulfill expansion performance requirements.

  16. Sensor development and integration for robotized laser welding

    OpenAIRE

    Iakovou, Dimitrios

    2009-01-01

    Laser welding requires fast and accurate positioning of the laser beam over the seam trajectory. The task of accurate positioning of the laser tools is performed by robotic systems. It is therefore necessary to teach the robot the path it has to follow. Seam teaching is implemented in several ways: Offline Programming, Manual Point-to-point, Sensor Guided. The first two processes are time consuming; the second requires constant human interaction, whereas the last one is fast and fully automat...

  17. Development of an automatic pipeline scanning system

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae H.; Lee, Jae C.; Moon, Soon S.; Eom, Heung S.; Choi, Yu R

    1999-11-01

    Pressure pipe inspection in nuclear power plants is one of the mandatory regulation items. Comparing to manual ultrasonic inspection, automatic inspection has the benefits of more accurate and reliable inspection results and reduction of radiation disposal. final object of this project is to develop an automatic pipeline inspection system of pressure pipe welds in nuclear power plants. We developed a pipeline scanning robot with four magnetic wheels and 2-axis manipulator for controlling ultrasonic transducers, and developed the robot control computer which controls the robot to navigate along inspection path exactly. We expect our system can contribute to reduction of inspection time, performance enhancement, and effective management of inspection results. The system developed by this project can be practically used for inspection works after field tests. (author)

  18. Microscopic weld evaluation of FBTR end plug welds

    International Nuclear Information System (INIS)

    SS316 Stainless steel has been chosen as a reference cladding material for Fast Breeder Test Reactor. Both the ends of the clad tubes are encapped with a solid stainless steel plug by Tungsten Inert Gas welding processes. Due to the thick-thin geometry of the end plug and the fuel clad tube, getting defect free weld joint is a challenging task. Microscopic weld evaluation of the weld defects of these end plug welds have been carried out as per standard ASTM metallography practice. Requirement of the good quality weld joint is very essential to contain the fission gas release and to enable it to sustain the high burn up of the fuel in the nuclear reactor. This paper presents the typical weld defects encountered during the development and fabrication of the actual fuel pin and it also shows some of the weld characteristics like multiple weld pool, spherical weld pool, through and through weld penetration, outer edge depression at the tube side and the plug side of the weld pool observed during the pin fabrication campaign. (author)

  19. State of the art of the welding method for sealing spent nuclear fuel canister made of copper. Part 1 - FSW

    International Nuclear Information System (INIS)

    The purpose of this report is to gather together comprehensive information concerning FSW as an optional welding method for welding the nuclear waste copper canister at the disposal facility. This report discusses the current situation, knowledge of the process and information concerning results of the development and research work related to welding thick copper and the special needs of the disposal environment. Most of the research work and development work has been done by Posiva's Swedish partner SKB, Swedish Nuclear Fuel and Waste Management Co. SKB chose FSW as their reference welding method in 2005. FSW (friction stir welding) is a solid-state welding method, invented in 1991, in which frictional heat is generated between the tool and the weld metal, causing the metal to soften, normally without reaching the melting point, and allowing the tool to traverse the joint line. Friction stir welding can be used for joining many types of materials and material combinations, if the tool materials and designs can be found which operate at the forging temperature of the workpiece. The general requirements for the copper canister weld and base material are presented in Posiva's VAHA-system, which sets the most critical values or demands concerning the short- and long-term properties or other needs. The sections in this report are set out in a similar way as in the VAHA-system. Concerning the results from the research and development work, it can be said that FS weld material fulfils the values set by VAHA. The quality of the welds fulfils the set demands for intact weld material and the welding process is robust using an automatic control system. There still remains work concerning the acceptance procedure for the welding process and other open issues which are described in this report. (orig.)

  20. State of the art of the welding method for sealing spent nuclear fuel canister made of copper. Part 1 - FSW

    Energy Technology Data Exchange (ETDEWEB)

    Purhonen, T.

    2014-05-15

    The purpose of this report is to gather together comprehensive information concerning FSW as an optional welding method for welding the nuclear waste copper canister at the disposal facility. This report discusses the current situation, knowledge of the process and information concerning results of the development and research work related to welding thick copper and the special needs of the disposal environment. Most of the research work and development work has been done by Posiva's Swedish partner SKB, Swedish Nuclear Fuel and Waste Management Co. SKB chose FSW as their reference welding method in 2005. FSW (friction stir welding) is a solid-state welding method, invented in 1991, in which frictional heat is generated between the tool and the weld metal, causing the metal to soften, normally without reaching the melting point, and allowing the tool to traverse the joint line. Friction stir welding can be used for joining many types of materials and material combinations, if the tool materials and designs can be found which operate at the forging temperature of the workpiece. The general requirements for the copper canister weld and base material are presented in Posiva's VAHA-system, which sets the most critical values or demands concerning the short- and long-term properties or other needs. The sections in this report are set out in a similar way as in the VAHA-system. Concerning the results from the research and development work, it can be said that FS weld material fulfils the values set by VAHA. The quality of the welds fulfils the set demands for intact weld material and the welding process is robust using an automatic control system. There still remains work concerning the acceptance procedure for the welding process and other open issues which are described in this report. (orig.)

  1. Ultrasonic inspection of austenitic welds

    International Nuclear Information System (INIS)

    The ultrasonic examination of austenitic stainless steel weld metal has always been regarded as a difficult proposition because of the large and variable ultrasonic attenuations and back scattering obtained from apparently similar weld deposits. The work to be described shows how the existence of a fibre texture within each weld deposit (as a result of epitaxial growth through successive weld beads) produces a systematic variation in the ultrasonic attenuation coefficient and the velocity of sound, depending upon the angle between the ultrasonic beam and the fibre axis. Development work has shown that it is possible to adjust the welding parameters to ensure that the crystallographic texture within each weld is compatible with improved ultrasonic transmission. The application of the results to the inspection of a specific weld in type 316 weld metal is described

  2. Automation and high-efficiency of welding in pipeline; Gas pipeline ni okeru yosetsu no jidoka to konoritsuka

    Energy Technology Data Exchange (ETDEWEB)

    Kawanishi, N.; Masuda, H.; Hara, Y.; Kimura, M. [Osaka Gas Co. Ltd., Osaka (Japan); Iimura, M. [Tokyo Gas Co. Ltd., Tokyo (Japan); Hayashi, K. [Toho Gas Co. Ltd., Nagoya (Japan); Mori, K.; Suesawa, S. [Japan Gas Association, Tokyo (Japan)

    1997-11-01

    With objectives to develop technologies which can perform a welding work automatically at ultra-high speed, improve efficiency in construction works of building town gas transporting pipelines, and make the welding quality uniform, a program that will last for six years has been established to make necessary discussions. Using a horizontally fixed pipe, AP15L-X65, with a diameter of 750 mm and a plate thickness of 19 mm as the object of the discussions, the following four welding processes were selected to implement the development on each process in parallel: high-speed TIG welding, high-speed oscillating MAG welding, plasma welding, and electron beam welding. In March 1997 by which the former half of the project has been completed, an arc time of less than 30 minutes has been achieved as one of the development targets. Using sizes of problems in innovativeness in technologies, welding quality, and practical application as criteria for an interim evaluation, focuses were directed on four technologies. As a result, the electron beam welding was selected, which has achieved an epoch-making result in arc time while maintaining good quality. In the latter half of the project which will end in March 2000, promotion efforts will be continued for discussing how to solve problems in electron beam welding machines, and making developments and field tests thereon. 7 refs., 20 figs., 5 tabs.

  3. Special metallurgy - the electrical butt-welding by flashing of sintered magnesium-magnesium oxide composites (1963)

    International Nuclear Information System (INIS)

    Electrical resistance welding has become quite important since World War II because of the need of a high yield in aeronautical production. Progress has been due in particular to the improvements made in electronically controlled apparatus making possible the automatic control of welding. For the butt-welding of sections requiring either a high production rate or a high quality weld, the flash butt-welding system has been very much developed these last few years. The use of this welding method is of great importance in the field of the bonding of oxidisable metals such as magnesium or aluminium and its alloys, because the welded joint is free from oxides. This study consists of general considerations on the flash-welding process with regard to temperature distribution in the parts during welding, and to electrical phenomena connected with flashing. Besides this general or theoretical section, we have applied the welding process to the bonding of sintered magnesium, a magnesium-magnesium oxide composite, whose use as a structural element in nuclear reactors is considered. (author)

  4. Laser welding of cylindrical parts

    OpenAIRE

    Närhi-Ratkovskaia, Olga

    2011-01-01

    The purpose of this paper is to conduct the laser welding work of the cylindrical parts, particularly fuel filters, according to the safety instructions. The welding was followed by the additional test for a gas resistance of filters. The topic was commissioned by the company Laserplus Oy, located in Hämeenlinna. The aim of the project on laser welding of filters was to find out optimum parameters for the company’s welding. Optimum parameters include the minimum laser power with optimum ...

  5. Creep of welded branched pipes

    OpenAIRE

    Rayner, Glen

    2004-01-01

    Creep failure of welds in high-temperature power plant steam piping systems is known to be a potential cause of plant failure. Creep behaviour of plain pipes with circumferential welds and cross-weld specimens have received fairly extensive attention. However, research into the creep behaviour of welded thick-walled branched steam pipes has received less attention. Consequently, this thesis addresses improving the understanding of the creep behaviour for this type of geometry. Numerical and a...

  6. Multipass autogenous electron beam welding

    International Nuclear Information System (INIS)

    A multipass, autogenous welding procedure was developed for 7.6 mm (0.3 in.) wall thickness Type 304L stainless steel cylinders. The joint geometry has a 1.5 mm (0.06 in.) root-face width and a rectangular stepped groove that is 0.762 mm (0.03 in.) wide at the top of the root face and extends 1.5 mm in height, terminating into a groove width of 1.27 mm which extends to the outside of the 1.27 mm high weld-boss. One weld pass is made on the root, three passes on the 0.762 mm wide groove and three passes to complete the weld. Multipass, autogenous, electron beam welds maintain the characteristic high depth-to-width ratios and low heat input of single-pass, electron beam welds. The increased part distortion (which is still much less than from arc processes) in multipass weldments is corrected by a preweld machined compensation. Mechanical properties of multipass welds compare well with single-pass welds. The yield strength of welds in aluminum alloy 5083 is approximately the same for single-pass or multipass electron beam and gas, metal-arc welds. The incidence and size of porosity is less in multipass electron beam welding of aluminum as compared to gas, metal-arc welds. The multipass, autogenous, electron beam welding method has proven to be a reliable way to make some difficult welds in multilayer parts or in an instance where inside part temperature or weld underbead must be controlled and weld discontinuities must be minimized

  7. Development of micro machining tools for finishing weld joint

    International Nuclear Information System (INIS)

    GE, Hitachi and Toshiba are jointly constructing advanced boiling water reactor (ABWR) Units 6 and 7 at Kashiwazaki Kariwa Nuclear Power Plant Station, Tokyo Electric Power Co. The ABWR features enhanced operability and safety as a whole plant through simplicity and improved performance. To achieve these improvement, one of the key features of technical innovation adopted in the ABWR design, ten reactor internal pumps (RIP) are adopted as the reactor recirculation system. The RIP casing to hold the RIP constituting the primary pressure boundary together with a RPV is welded to the nozzle on a RPV lower shell with Gas Tungsten Arc Welding (GTAW). The welding is on V-groove using automatic GTAW technique from the inside of the casing. The penetration bead (the back side of the weld) therefore needs to be finished with machining tools to inspect the qualification of the welding. This paper summarizes the development of the special purpose micro machines which are installed inside the narrow gap being provided between the RIP casing and the RPV (skirt) to finish the penetration bead. (author)

  8. NTWV-based sensing keyhole dimension in plasma arc welding

    Institute of Scientific and Technical Information of China (English)

    Jia Chuanbao; Wu Chuansong; Zhang Yuming

    2008-01-01

    During stable keyhole plasma arc welding, the pilot arc and the transferred arc exist at the meantime, and the arcs can be considered as a composition of two parts inside and outside the nozzle, respectively. Under the mechanical constriction and thermal contraction effects, the inside arc has certain arc length, electron density and arc profile etc. Inducing constant tungsten-to-nozzle voltage. However, the arc outside the nozzle diverges at about 5 degrees and has certain characteristics similar to the free arcs. The nozzle-to-workpiece voltage (NTWV) depends mainly on the length of the arc, which gets bigger as increasing of the weld penetration and keyhole size. The NTWV sensor is developed for monitoring NTWV in real time. The welding experiments are designed to get different penetrations and keyhole sizes. It is found that as the weld penetration and the keyhole size increase, NTWV also increases linearly. The NTWV signals can be used as the feedback variable in automatic control of keyhole plasma arc welding.

  9. Laser welding of polymers using high-power diode lasers

    Science.gov (United States)

    Bachmann, Friedrich G.; Russek, Ulrich A.

    2003-09-01

    Laser welding of polymers using high power diode lasers offers specific process advantages over conventional technologies, such as short process times while providing optically and qualitatively valuable weld seams, contactless yielding of the joining energy, absence of process induced vibrations, imposing minimal thermal stress and avoiding particle generation. Furthermore this method exhibits high integration capabilities and automatization potential. Moreover, because of the current favorable cost development within the high power diode laser market laser welding of polymers has become more and more an industrially accepted joining method. This novel technology permits both, reliable high quality joining of mechanically and electronically highly sensitive micro components and hermetic sealing of macro components. There are different welding strategies available, which are adaptable to the current application. Within the frame of this discourse scientific and also application oriented results concerning laser transmission welding of polymers using preferably diode lasers are presented. Besides the used laser systems the fundamental process strategies as well as decisive process parameters are illustrated. The importance of optical, thermal and mechanical properties is discussed. Applications at real technical components will be presented, demonstrating the industrial implementation capability and the advantages of a novel technology.

  10. Welding. Performance Objectives. Basic Course.

    Science.gov (United States)

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of eight terminal objectives for a basic welding course. The materials were developed for a 36-week (2 hours daily) course developed to teach the fundamentals of welding shop work, to become familiar with the operation of the welding shop…

  11. Welding. Performance Objectives. Intermediate Course.

    Science.gov (United States)

    Vincent, Kenneth

    Several intermediate performance objectives and corresponding criterion measures are listed for each of nine terminal objectives for an intermediate welding course. The materials were developed for a 36-week (3 hours daily) course designed to prepare the student for employment in the field of welding. Electric welding and specialized (TIG & MIG)…

  12. Laser welding engineering

    International Nuclear Information System (INIS)

    Laser welding was in its early life used mainly for unusual applications where no other welding process would be suitable that was twenty five years ago. Today, laser welding is a fully developed part of the metal working industry, routinely producing welds for common items such as cigarette lighters, which springs, motor/transformer lamination, hermetic seals, battery and pacemaker cans and hybrid circuit packages. Yet very few manufacturing engineering have seriously considers employing lasers in their own operations. Why? There are many reasons, but a main one must be not acquainted with the operation and capabilities of a laser system. Other reasons, such as a relatively high initial cost and a concern about using lasers in the manufacturing environment, also are frequently cited, and the complexity of the component and flexibility of the light delivery system. Laser welding could be used in place of many different standard processes, such as resistance (spot or seam), submerged arc, RF induction, high-frequency resistance, ultrasonic and electronic and electron-beam. while each of these techniques has established an independent function in the manufacturing world, the flexible laser welding approach will operate efficiently and economically in many different applications. Its flexibility will even permit the welding system to be used for other machining function, such as drilling, scribing, sealing and serializing. In this article, we will look at how laser welding works and what benefits it can offer to manufacturing engineers. Some industry observers state that there are already 2,000 laser machine tools being used for cutting, welding and drilling and that the number could reach 30,000 over the next 15 years as manufacturing engineers become more aware of the capabilities of lasers [1). While most laser applications are dedicated to one product or process that involves high-volume, long-run manufacturing, the flexibility of a laser to supply energy to hard

  13. Friction stir welding tool and process for welding dissimilar materials

    Science.gov (United States)

    Hovanski, Yuri; Grant, Glenn J; Jana, Saumyadeep; Mattlin, Karl F

    2013-05-07

    A friction stir welding tool and process for lap welding dissimilar materials are detailed. The invention includes a cutter scribe that penetrates and extrudes a first material of a lap weld stack to a preselected depth and further cuts a second material to provide a beneficial geometry defined by a plurality of mechanically interlocking features. The tool backfills the interlocking features generating a lap weld across the length of the interface between the dissimilar materials that enhances the shear strength of the lap weld.

  14. Genetic Algorithm Coupled with the Neural Network for Fatigue Properties of Welding Joints Predicting

    Directory of Open Access Journals (Sweden)

    Nan Zhou

    2012-08-01

    Full Text Available The prediction of fatigue life of metal welded joints plays an important role at lower manufacturing costs and reduces accidents for engineering materials, the response of metal welded joints to fatigue properties has highly non-linear, so it is difficult to establish an accurate theoretical model using traditional method to predict its fatigue life. It is appropriate to consider modeling methods developed in other fields in order to provide adequate models for metal welded joints behavior on fatigue properties. Accordingly, a new system predict method, based on a hybrid genetic algorithm (GA with the Back-propagation neural network (BPNN, for the simultaneous establishment of a predict model structure of fatigue life of metal welded joints and the related parameters is proposed. Based on the self-learning ability and approximation of non-linear mapping capability of the BPNN, by taking the advantages of the powerful ability of global optimization, implicit parallelism and high stability of the GA, the optimal parameters have been automatically determined, we establish a parameter adaptive optimization of GANN model to fit and predict the fatigue life of metal welded joints. GANN establishes the mapping relationship between the fatigue properties of metal welded joints and a variety of influencing factors, having greatly increased the computational efficiency for the fatigue properties of metal welded joints, also had a higher predict accuracy. The superiority of GANN had been tested by the prediction of the fatigue life of welded joints in different process parameters.

  15. Integrated sensors for robotic laser welding

    OpenAIRE

    Iakovou, D.; Aarts, R.G.K.M.; Meijer, J.; Beyer, E.; Dausinger, F.; Ostendorf, A.; Otto, A.

    2005-01-01

    A welding head is under development with integrated sensory systems for robotic laser welding applications. Robotic laser welding requires sensory systems that are capable to accurately guide the welding head over a seam in three-dimensional space and provide information about the welding process as well as the quality of the welding result. In this paper the focus is on seam tracking. It is difficult to measure three-dimensional parameters of a ream during a robotic laser welding task, espec...

  16. ON INTELLIGENTIZED TECHNOLOGIES FOR MODERN WELDING MANUFACTURING

    Institute of Scientific and Technical Information of China (English)

    Chen Shanben; Qiu Tao; Lin Tao; Wu Yixiong

    2003-01-01

    A short survey on researching and developing status of intelligent technologies in modem welding manufacturing is given. According to the developing trend of advanced manufacturing technology, a concept on intelligentized welding manufacturing engineering (IWME), is presented for systematization of researching and developing domains on welding automation, intelligentized welding,robotic and flexible welding and advanced welding manufacturing technologies. And key technologies of welding intelligent manufacturing and its developing trend in the future are investigated.

  17. Control of weld quality in large welded populations

    International Nuclear Information System (INIS)

    The use of factorial experimental design during weld procedure development, as a statistical tool for the control of weld quality in large welded populations, is investigated. As an example, it is applied to single pass welds made in the laboratory using the spacer to tube attachment geometry present in AGR boilers. The welds have been deposited using a robotic cold wire TIG technique. A replicated 25 factorial welding trial has been designed and evaluated experimentally. Transverse sections have been examined to determine weld penetration quality features. The means and variances of each quality feature have been calculated. Using a standard factorial analysis program the significant effects have been identified and incorporated into control equations. Using these data and having established minimum acceptance criteria. defect rates have been calculated as a function of weld position. The control equations have also been used to revise working point welding conditions, to achieve acceptable weld quality. These equations have also been used in conjunction with the reproducibility measurements to estimate the amount of weld quality variability that can be attributed to process control. (author)

  18. Weld pool image sensor for pulsed MIG welding

    Institute of Scientific and Technical Information of China (English)

    Liu Pengfei; Sun Zhenguo; Huang Cao; Chen Qiang

    2008-01-01

    Visual image sensor is developed to detect the weld pool images in pulsed MIG welding. An exposure controller, which is composed of the modules of the voltage transforming, the exposure parameters presetting, the complex programmable logic device (CPLD) based logic controlling, exposure signal processing, the arc state detecting, the mechanical iris driving and so on, is designed at first. Then, a visual image sensor consists of an ordinary CCD camera, optical system and exposure controller is established. The exposure synchronic control logic is described with very-high-speed integrated circuit hardware description language (VHDL) and programmed with CPLD, to detect weld pool images at the stage of base current in pulsed MIG welding. Finally, both bead on plate welding and V groove filled welding are carried out, clear and consistent weld pool images are acquired.

  19. Weld Nugget Temperature Control in Thermal Stir Welding

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2014-01-01

    A control system for a thermal stir welding system is provided. The control system includes a sensor and a controller. The sensor is coupled to the welding system's containment plate assembly and generates signals indicative of temperature of a region adjacent and parallel to the welding system's stir rod. The controller is coupled to the sensor and generates at least one control signal using the sensor signals indicative of temperature. The controller is also coupled to the welding system such that at least one of rotational speed of the stir rod, heat supplied by the welding system's induction heater, and feed speed of the welding system's weld material feeder are controlled based on the control signal(s).

  20. On Improvement of Semiautomatic CO2 Gas Shielded Arc Welding Device%半自动CO2气体保护焊接装置自动化改造

    Institute of Scientific and Technical Information of China (English)

    姚宗湘; 毛正通; 孙超群; 武晓丽; 李现堂

    2011-01-01

    In the context of the lack of automatic welding in the welding lab,a concrete improvement program was carried out through an analysis of the welding equipment in order to promote the speed stability of welding.The design will increase the stability and decrease the human errors in welding process.%结合学校现有实验条件,对半自动CO2气保悍进行技术改造,改善悍接质量的稳定性,减少人为因素对悍接质量的影响。

  1. Welding Molecular Crystals.

    Science.gov (United States)

    Adolf, Cyril R R; Ferlay, Sylvie; Kyritsakas, Nathalie; Hosseini, Mir Wais

    2015-12-16

    Both for fundamental and applied sciences, the design of complex molecular systems in the crystalline phase with strict control of order and periodicity at both microscopic and macroscopic levels is of prime importance for development of new solid-state materials and devices. The design and fabrication of complex crystalline systems as networks of crystals displaying task-specific properties is a step toward smart materials. Here we report on isostructural and almost isometric molecular crystals of different colors, their use for fabrication of core-shell crystals, and their welding by 3D epitaxial growth into networks of crystals as single-crystalline entities. Welding of crystals by self-assembly processes into macroscopic networks of crystals is a powerful strategy for the design of hierarchically organized periodic complex architectures composed of different subdomains displaying targeted characteristics. Crystal welding may be regarded as a first step toward the design of new hierarchically organized complex crystalline systems. PMID:26581391

  2. Development of multifunction laser welding head (1). Evaluation of under water laser welding with multifunction laser welding head

    International Nuclear Information System (INIS)

    Multifunction laser welding head has been developed. The head is able to perform not only underwater laser welding as repair, but also laser peening as preventive maintenance and laser ultrasonic testing as inspection. Laser transmission test with multifunction laser welding head and optical fiber was carried out. The result showed that laser power needed for welding was transmitted without any damage to them. Under water laser welding onto EDM slits with this welding head was carried out. EDM slits were sealed by deposited weld metal. It was confirmed that multifunction laser welding head was applied to under water laser welding. (author)

  3. New welding technologies for car body frame welding

    Directory of Open Access Journals (Sweden)

    T. Węgrzyn

    2012-12-01

    Full Text Available Purpose: of that paper was analysing main welding process for car body welding. The main reason of it was investigate possibilities of getting varied amount of acicular ferrite (AF in WMD (weld metal deposit. High amount of acicular ferrite influences positively impact toughness of weld. For optimal amount of AF it is necessary to have optimal chemical composition in WMD. Important role plays especially Ni. There were also tested new welding technology: welding with micro-jet cooling.Design/methodology/approach: During research with varied micro-jet parameters the chemical analysis, micrograph tests and Charpy V impact test of the metal weld deposit on pendulum machine were carried out. The Charpy V impact test was prepared according to standard ISO EN 148-1 Metallic materials - Charpy pendulum impact test - Part 1: Test method. Samples for impact testing were prepared according to standard ASTM A370.Findings: Varied amount of acicular ferrite in weld metal deposit (in range 55-75% in terms of microjet cooling parameters (numbers of jet, gas pressure. This high amount of acicular ferrite is unheard in weld metal deposit in another way or other methods of welding like MAG or TIG.Research limitations/implications: That research was made for MIG method (according to PN-EN ISO 4063:2009 only. Another method of welding in this article was not tested. Other methods (for eg. MAG, TIG have not been tested, but it is suspected that similar phenomena are taking place.Originality/value: In this research new method of cooling weld joint during welding was used. At the present time use of micro-jet cooling while MIG is in the testing phase and requires an accurate diagnosis.This method is very promising and capable of industrial application, mainly due to the significant improvement of weld quality and reduces costs.

  4. Fundamental Laser Welding Process Investigations

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove

    1998-01-01

    In a number of systematic laboratory investigations the fundamental behavior of the laser welding process was analyzed by the use of normal video (30 Hz), high speed video (100 and 400 Hz) and photo diodes. Sensors were positioned to monitor the welding process from both the top side and the rear...... side of the specimen.Special attention has been given to the dynamic nature of the laser welding process, especially during unstable welding conditions. In one series of experiments, the stability of the process has been varied by changing the gap distance in lap welding. In another series...

  5. The Effect of Welding Speed on the Microstructure and Penetration in Arc Welding

    OpenAIRE

    DURGUTLU, Ahmet; GÜLENÇ, Behçet

    1999-01-01

    The effect of welding speed on the microstructure and penetration in MAG, SMAW and MMA welding was investigated in a low carbon steel. Experimental results revealed that the penetration decreased when the welding speed was lower or higher than the optimum speed. It was also observed that when the welding speed was high, undercuttings occurred at the edge of welding bead and microstructure of weld metals consisted of fine grains, but when the welding speed was low, at the edge of weld...

  6. Ultrasonic inspection of austenitic welds

    International Nuclear Information System (INIS)

    The metallurgical structure of austenitic welds is described and contrasted with that found in ferritic welds. It is shown that this structure imparts a marked elastic anisotropy in the ultrasonic propagation parameters. Measurements of variations in the apparent attenuation of sound and deviations in the beam direction are described. The measurements are interpreted in terms of the measured velocity anisotropy. Two applications of the fundamental work are described. In the first it is shown how, by using short pulse compression wave probes, and with major modification of the welding procedure, a stainless steel fillet weld in an AGR boiler can be inspected. In the second application, alternative designs of a transition butt weld have been compared for ease of ultrasonic inspection. The effects of two different welding processes on such an inspection are described. Finally, the paper examines the prospects for future development of inspection and defect-sizing techniques for austenitic welds. (author)

  7. Welding technology transfer task/laser based weld joint tracking system for compressor girth welds

    Science.gov (United States)

    Looney, Alan

    1991-01-01

    Sensors to control and monitor welding operations are currently being developed at Marshall Space Flight Center. The laser based weld bead profiler/torch rotation sensor was modified to provide a weld joint tracking system for compressor girth welds. The tracking system features a precision laser based vision sensor, automated two-axis machine motion, and an industrial PC controller. The system benefits are elimination of weld repairs caused by joint tracking errors which reduces manufacturing costs and increases production output, simplification of tooling, and free costly manufacturing floor space.

  8. ICT diagnostic method of beryllium welding quality

    International Nuclear Information System (INIS)

    To avoid the interference of high density material for the quality assay of beryllium welding line, a slice by slice scanning method was proposed based upon the research results of the Industrial Computerized Tomography (ICT) diagnostics for weld penetration, weld width, off-centered deviation and weld defects of beryllium-ring welding seam with high density material inside

  9. Welding Development: Marshall Space Flight Center

    Science.gov (United States)

    Ding, Jeff

    2007-01-01

    This paper presents the basic understanding of the friction stir welding process. It covers process description, pin tool operation and materials, metal flow theory, mechanical properties, and materials welded using the process. It also discusses the thermal stir welding process and the differences between thermal stir and friction stir welding. MSFC weld tools used for development are also presented.

  10. Sensor integration for robotic laser welding processes

    NARCIS (Netherlands)

    Iakovou, Dimitrios; Aarts, Ronald; Meijer, Johan

    2005-01-01

    The use of robotic laser welding is increasing among industrial applications, because of its ability to weld objects in three dimensions. Robotic laser welding involves three sub-processes: seam detection and tracking, welding process control, and weld seam inspection. Usually, for each sub-process,

  11. Deconvoluting the Friction Stir Weld Process for Optimizing Welds

    Science.gov (United States)

    Schneider, Judy; Nunes, Arthur C.

    2008-01-01

    In the friction stir welding process, the rotating surfaces of the pin and shoulder contact the weld metal and force a rotational flow within the weld metal. Heat, generated by the metal deformation as well as frictional slippage with the contact surface, softens the metal and makes it easier to deform. As in any thermo-mechanical processing of metal, the flow conditions are critical to the quality of the weld. For example, extrusion of metal from under the shoulder of an excessively hot weld may relax local pressure and result in wormhole defects. The trace of the weld joint in the wake of the weld may vary geometrically depending upon the flow streamlines around the tool with some geometry more vulnerable to loss of strength from joint contamination than others. The material flow path around the tool cannot be seen in real time during the weld. By using analytical "tools" based upon the principles of mathematics and physics, a weld model can be created to compute features that can be observed. By comparing the computed observations with actual data, the weld model can be validated or adjusted to get better agreement. Inputs to the model to predict weld structures and properties include: hot working properties ofthe metal, pin tool geometry, travel rate, rotation and plunge force. Since metals record their prior hot working history, the hot working conditions imparted during FSW can be quantified by interpreting the final microstructure. Variations in texture and grain size result from variations in the strain accommodated at a given strain rate and temperature. Microstructural data from a variety of FSWs has been correlated with prior marker studies to contribute to our understanding of the FSW process. Once this stage is reached, the weld modeling process can save significant development costs by reducing costly trial-and-error approaches to obtaining quality welds.

  12. Welding in nuclear engineering

    International Nuclear Information System (INIS)

    The 3rd international conference 'Welding in nuclear engineering', organized in 1978 by the Deutscher Verband fuer Schweisstechnik e.V., was, like the two foregoing conferences in 1970 and 1974, an absolute success. The noteworthy echo to this meeting in the international technical world - the number of 650 participants from 26 countries is self-evidence - and this fact, was for the Deutscher Verband fuer Schweisstechnik e.V. occasion and at the same time an obligation now to follow in the same way, the meeting that was started 12 years ago, by organizing the international conference 'Welding in nuclear engineering'. The conference this year offers in addition to the two plenary session lectures, 34 short reports and a further 28 single contributions in the form of two poster-sessions. Unfortunately, it was again not possible to accept all the papers submitted because the conference was limited to 2 days only. Nevertheless, the papers will offer a representative cross-section through the total range of welding engineering. In particular, the poster session, which take place for the first time within the scope of a meeting organized by the Working Group 'Welding in Nuclear Engineering', should contribute to the aim that this time again the discussions will form the main point of the conference. (orig./RW)

  13. Welding. Student Learning Guide.

    Science.gov (United States)

    Palm Beach County Board of Public Instruction, West Palm Beach, FL.

    This student learning guide contains 30 modules for completing a course in welding. It is designed especially for use in secondary schools in Palm Beach County, Florida. Each module covers one task, and consists of a purpose, performance objective, enabling objectives, learning activities keyed to resources, information sheets, student self-check…

  14. Thermal Stresses in Welding

    DEFF Research Database (Denmark)

    Hansen, Jan Langkjær

    1998-01-01

    Studies of the transient temperature fields and the hereby induced deformations and stressses in a butt-welded mild steel plate modelledrespectively in 2D plane stress state (as well as plane strain state) and in full 3D have been done. The model has been implemented in the generalpurpose FE...

  15. Recent development of automation, robotization CIM based on systematization of welding operations in the shipyard; Yosetsu no jidoka robot ka CIM ka ni okeru zosen no taio to kongo no hoko

    Energy Technology Data Exchange (ETDEWEB)

    Iwabuchi, H. [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)

    1997-12-01

    This paper describes history, current status and future direction of automation, robotization and CIM during welding operations in the shipbuilding industry. The shipbuilding industry in Japan has experienced big booms and slumps for 20 years from the 1970`s to the 1990`s. Improvement of productivity by introducing welding robots has greatly contributed to the recovery basis in the 1990`s. For example showing current status, sub-assembly welding robots can automatically make their operation data and work by means of off-line teaching method from design information including shape. In the curved large-scale assembly process, welding is automatically performed only using inputting designed data of ship type by combining automatic setting of outer plates with positioner. Improvement of accuracy, robotization of welding of curved part, and field works without monitoring are essential in the future. Development combined with image analysis technology is to be promoted. 4 refs., 16 figs., 1 tab.

  16. Improvements in and relating to welding

    International Nuclear Information System (INIS)

    This invention concerns apparatus for use in welding, particularly welding which must be effected in a predetermined, for example, inert atmosphere, e.g. the welding of reactive materials such as zircaloy, titanium, magnesium, aluminium, etc. (U.K.)

  17. Horizontal electron beam welding for stainless steels

    International Nuclear Information System (INIS)

    Stainless steel samples have been realized by local vacuum apparatus for electron beam welding applications to reactor core shell realizations. The best welding parameters have been determined by a systematic study. The welds have been characterized by mechanical tests

  18. Fundamental Difficulties Associated With Underwater Wet Welding

    OpenAIRE

    Joshua E. Omajene,; Jukka Martikainen

    2014-01-01

    The offshore industries carry out welding activities in the wet environment. It is evident that the wet environments possess difficulties in carrying out underwater welding. Therefore there is the need to improve the quality of weld achieved in underwater welding. This paper investigates the difficulties associated with underwater welding. The objective of this research paper is to identify and analyze the different difficulties in underwater welding so as to make a clear back...

  19. Creep rupture properties of trial welded joints of a Ni-Cr-W superalloy in air environment

    International Nuclear Information System (INIS)

    The item to be solved in order to put the Ni-Cr-W superalloy to practical use is development of filler metal. Therefore, creep properties of trial welded joints were estimated. Filler metals whose susceptibility to cracking in the weldments was lowered by adjusting minor alloying elements, were melted. Three kinds of trial welded joints F, P5 and P6 were prepared by means of manual TIG(Tungsten Inert Gas) welding. Creep rupture properties in air environment were investigated at 900, 1000 and 1050degC for the trial welded joints. The results obtained were as follows: (1)Creep rupture time for trial welded joints F, P5 and P6 is almost as the same as or a little shorter than that for the base metal of Ni-Cr-W superalloy with grain size of ASTM No.2 and creep rupture strength of 10.8MPa for a 1x105h life at 1000degC. Creep rupture strength of the trial welded joints is fairly good as welded joints used at high temperatures. (2)Rupture location is the base metal at 900degC and it becomes the welded metal at 1000 and 1050degC. Reduction of area is small in case rupture occurs at the weld metal. (3)Voids and cracks form at grain boundaries in the case of rupture at the base metal. They also form at grain boundaries of the weld metal in the case of rupture at the weld metal. Since susceptibility to cracking in the weldments of a Ni-Cr-W superalloy was very high, development of filler metal with good weldability was difficult. However, it was found that trial welded joints prepared using the filler metals with good weldability have fairly good creep properties. Research for development of the filler metal with excellent weldability, creep properties, corrosion resistance and hot workability will be performed in focusing quantitative estimation of effect of minor alloying elements on susceptibility to cracking in the weldments, preparation of filler wires for automatic TIG welding and estimation of creep properties for the welded joints by automatic TIG welding. (author)

  20. PRODUCTION OF METAL CHEMICAL WELDING ADDITIVE WITH NANODISPERSED PARTICLES OF TITANIUM DIOXIDE

    Directory of Open Access Journals (Sweden)

    BOLDYREV Alexander Mikhaylovich

    2013-12-01

    Full Text Available When welding bridge structures automatic welding under a gumboil layer with metal chemical additive (MCA is widely applied in the modern bridge building. MCA consists of a chopped welding wire (granulated material, which is powdered by modifying chemical additive of titanium dioxide (TiO₂ in the cylindrical mixer «drunk cask». Chemical composition of all welding materials including welding wire, gumboil, electrodes, are strictly normalized and controlled. However, the existing technology of producing MCA doesn’t allow precise controlling of its structure under working conditions and that causes an impact on the stability of welded connections properties. Therefore the aim of this work is to develop a technology to produce stable MCA structure. The paper compares the existing and proposed manufacturing techniques of the metal chemical additive (MCA which is applied in automatic welding of butt connections for bridge structures. It is shown that production of MCA in a high-energy planetary mill provides more stable structure of the additive introduced into a welded joint. The granulometric analysis of the powder TiO₂ showed that when processing MCA in a planetary mill TiO₂ particles are crashed to nanodimensional order. This process is accompanied by crushing of granulated material too. The proposed method for production of MCA in a planetary mill provides stronger cohesion of dioxide with the granulate surface and, as a consequence, more stable MCA chemical structure. Application of MCA which has been mechanical intensified in a planetary mill, increases stability of mechanical properties, if compare with applied technology, in single-order by breaking point and almost twice by impact viscosity.

  1. Industrial laser welding evaluation study

    Science.gov (United States)

    Hella, R.; Locke, E.; Ream, S.

    1974-01-01

    High power laser welding was evaluated for fabricating space vehicle boosters. This evaluation was made for 1/4 in. and 1/2 in. aluminum (2219) and 1/4 in. and 1/2 in. D6AC steel. The Avco HPL 10 kW industrial laser was used to perform the evaluation. The objective has been achieved through the completion of the following technical tasks: (1) parameter study to optimize welding and material parameters; (2) preparation of welded panels for MSFC evaluation; and (3) demonstration of the repeatability of laser welding equipment. In addition, the design concept for a laser welding system capable of welding large space vehicle boosters has been developed.

  2. Models of plasma arc welding

    International Nuclear Information System (INIS)

    A complex model of energy transfer from ionized gas through a weld-pool to a heat affected zone (HAZ) is considered here. The model consists of three sub-models: a model of the arc column with skin layers - sheaths coating electrodes, a model of liquid metal flow in a weld-pool, and a model of coupled thermo-mechanical-metallurgical processes in HAZ. These sub-models are descried in three reports. The first report is devoted to a short review of welding plasma models based mostly on the Magneto-Hydro-Dynamics (MHD) theory successfully applied to the simulation of welding process. This report is illustrated by arc models for TIG and PAW welding. The description of thermal energy transfer between three sub-regions of the complex welding domain refers to a large number of processes observed in gaseous electronics, thermodynamics of reacting gases, electro-dynamics of fluid, micro-metallurgy. (author)

  3. Corrosion of carbon steel welds

    International Nuclear Information System (INIS)

    This report assesses the factors which cause preferential attack to occur in carbon steel fusion welds. It was concluded that the main factors were: the inclusion content of the weld metal, the potential of the weld metal being less noble than that of the parent, and the presence of low-temperature transformation products in the heat-affected zone of the weld. These factors should be minimized or eliminated as appropriate so that the corrosion allowances determined for carbon steel waste drums is also adequate for the welds. An experimental/theoretical approach is recommended to evaluate the relative corrosion resistance of welds prepared from BS 4360 grade 43A steel to that of the parent material. (author)

  4. Overlay welding irradiated stainless steel

    International Nuclear Information System (INIS)

    An overlay technique developed for welding irradiated stainless steel may be important for repair or modification of fusion reactor materials. Helium, present due to n,α reactions, is known to cause cracking using conventional welding methods. Stainless steel impregnated with 3 to 220 appm helium by decay of tritium was used to develop a welding process that could be used for repair. The result was a gas metal arc weld overlay technique with low-heat input and low-penetration into the helium-containing material. Extensive metallurgical and mechanical testing of this technique demonstrated substantial reduction of helium embrittlement damage. The overlay technique was applied to irradiated 304 stainless steel containing 10 appm helium. Surface cracking, present in conventional welds made on the same steel at lower helium concentrations, was eliminated. Underbead cracking, although greater than for tritium charged and aged material, was minimal compared to conventional welding methods

  5. Automatic input rectification

    OpenAIRE

    Long, Fan; Ganesh, Vijay; Carbin, Michael James; Sidiroglou, Stelios; Rinard, Martin

    2012-01-01

    We present a novel technique, automatic input rectification, and a prototype implementation, SOAP. SOAP learns a set of constraints characterizing typical inputs that an application is highly likely to process correctly. When given an atypical input that does not satisfy these constraints, SOAP automatically rectifies the input (i.e., changes the input so that it satisfies the learned constraints). The goal is to automatically convert potentially dangerous inputs into typical inputs that the ...

  6. Automatic Fiscal Stabilizers

    Directory of Open Access Journals (Sweden)

    Narcis Eduard Mitu

    2013-11-01

    Full Text Available Policies or institutions (built into an economic system that automatically tend to dampen economic cycle fluctuations in income, employment, etc., without direct government intervention. For example, in boom times, progressive income tax automatically reduces money supply as incomes and spendings rise. Similarly, in recessionary times, payment of unemployment benefits injects more money in the system and stimulates demand. Also called automatic stabilizers or built-in stabilizers.

  7. Irradiation stability of welded joints

    International Nuclear Information System (INIS)

    Results are presented of investigations into the neutron irradiation stability of welded joints in two types of steel used for reactor pressure vessels. Details are given of the materials used, method of welding and tests applied. The effect of irradiation on the notch toughness transition curve is shown. The results of the studies into irradiation embrittlement of all the welded joints and parent materials of the steels for the pressure vessels are summarized. (U.K.)

  8. Residual stresses in welded structures

    International Nuclear Information System (INIS)

    The nature of residual stresses in welded structures is discussed in terms of their magnitude, directionality, spatial distribution, range and variability. The effects of the following factors on the residual stresses are considered: material properties, material manufacture, structural geometry, fabrication procedure, welding procedure, post-weld treatments and service conditions. Examples are given of residual stress distributions in plate butt welds, circumferential butt welds and weld cladding. These illustrate the different magnitudes and distributions of residual stress that can be found in different joint geometries, and demonstrate the effects of the mechanical, thermal and metallurgical properties of the constituent materials and the sensitivity of residual stresses to pass sequence and to the restraints applied during welding. Further examples for the common case of circumferential butt welds in pipes and pressure vessels are used to illustrate the extent of residual stresses as a function of distance from the weld and the effects of post-weld heat treatment. Measurements or analytical predictions of residual stresses are often subject to significant scatter or variability. This scatter may be due to systematic factors such as variability in measurement location or material properties, or to experimental error in measured data, erroneous assumptions in analytical modelling or unknown factors such as pre-existing residual stresses, inadequately documented welding or fabrication procedures or unrecorded local repairs. Improved prediction and reduction of uncertainty of residual stresses will require better recording of the whole manufacturing and service history of the welded structure and its component materials and better understanding and analysis of the many processes that may affect the residual stresses

  9. Pulsed ultrasonic stir welding system

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2013-01-01

    An ultrasonic stir welding system includes a welding head assembly having a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. During a welding operation, ultrasonic pulses are applied to the rod as it rotates about its longitudinal axis. The ultrasonic pulses are applied in such a way that they propagate parallel to the longitudinal axis of the rod.

  10. Collection of arc welding process data

    Directory of Open Access Journals (Sweden)

    K. Luksa

    2006-04-01

    Full Text Available Purpose: The aim of the research was to examine the possibility of detecting welding imperfections by recording the instant values of welding parameters. The microprocessor controlled system for real-time collection and display of welding parameters was designed, implemented and tested.Design/methodology/approach: The system records up to 4 digital or analog signals collected from welding process and displays their run on the LCD display. To disturb the welding process artificial disturbances were introduced.Findings: The occurrence of some welding imperfections is followed by changes of the welding parameters. In this case they can be revealed by the analysis of the instant values of the welding parameters.Research limitations/implications: In the paper results of monitoring manual metal arc welding and gas metal arc welding are presented.Practical implications: Monitoring of gas metal arc welding is a good tool for evaluation of the quality of weld. All introduced, artificial disturbances of the welding process destabilize the welding arc and produce changes in the instant values of the welding parameters.Originality/value: The paper presents a modern microprocessor controlled system for real-time collection and display of welding parameters. Results of tests show that simple statistical approach to welding parameters can help in evaluation of weld quality.

  11. Fuel rod welding (LWBR development program)

    International Nuclear Information System (INIS)

    Procedures were developed to weld both ends of approximately 25,000 fuel rods for the Light Water Breeder Reactor (LWBR) core. The rods were welded using the gas tungsten arc (GTA) method in high-purity helium at 1 atmosphere. Welding parameters, including weld current, arc gap, and speed of rotation, were established to control the size of the weld. Electrode and chill positioning with respect to the endclosure/tube joint controlled the location of the weld. Weld quality of the fuel rods was ensured by 100-percent nondestructive testing by ultrasonic and radiographic inspection and the destructive evaluation of process control samples in each weld lot

  12. Welding zircaloy thin tubes to end plugs

    International Nuclear Information System (INIS)

    This work aimed at optimizing parameters while welding zircaloy-2 tubes with end plugs, as a simulation of a part of the fabrication of the nuclear fuel pins. Samples were welded by tungsten-inert gas-arc welding (TIC) process under controlled atmosphere of pure argon. Some samples were welded using electron beam (EB) welding process. For samples welded using TIC process both the design of the welding chamber (size and tightness) , and the purity of the shielding atmosphere were found to have appreciable effect on the quality of the welded joint. Increasing the are length and/or the welding current increases grain growth and extends both fusion and heat-affected zones. However, heat input (are length and welding current) must be high enough to give complete penetration welds. Optimum are length of 1.2 mm was found to give good welds with the smallest possible heat affected and fusion zones. Optimum parameters of EB welding process (vacuum, welding current and EB amplitude) were determined. welds prepared by EB welding were found to have finer grain size and less extended fusion and heat-affected zones. Welds prepared by both TIC and EB processes were inspected visually, metallo graphically and by using X-ray radiography. Welds integrity were tested using helium leak and pressure tests. 7 figs

  13. Automatic differentiation bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Corliss, G.F. (comp.)

    1992-07-01

    This is a bibliography of work related to automatic differentiation. Automatic differentiation is a technique for the fast, accurate propagation of derivative values using the chain rule. It is neither symbolic nor numeric. Automatic differentiation is a fundamental tool for scientific computation, with applications in optimization, nonlinear equations, nonlinear least squares approximation, stiff ordinary differential equation, partial differential equations, continuation methods, and sensitivity analysis. This report is an updated version of the bibliography which originally appeared in Automatic Differentiation of Algorithms: Theory, Implementation, and Application.

  14. Development of an automatic reactor inspection system

    International Nuclear Information System (INIS)

    Using recent technologies on a mobile robot computer science, we developed an automatic inspection system for weld lines of the reactor vessel. The ultrasonic inspection of the reactor pressure vessel is currently performed by commercialized robot manipulators. Since, however, the conventional fixed type robot manipulator is very huge, heavy and expensive, it needs long inspection time and is hard to handle and maintain. In order to resolve these problems, we developed a new automatic inspection system using a small mobile robot crawling on the vertical wall of the reactor vessel. According to our conceptual design, we developed the reactor inspection system including an underwater inspection robot, a laser position control subsystem, an ultrasonic data acquisition/analysis subsystem and a main control subsystem. We successfully carried out underwater experiments on the reactor vessel mockup, and real reactor ready for Ulchine nuclear power plant unit 6 at Dusan Heavy Industry in Korea. After this project, we have a plan to commercialize our inspection system. Using this system, we can expect much reduction of the inspection time, performance enhancement, automatic management of inspection history, etc. In the economic point of view, we can also expect import substitution more than 4 million dollars. The established essential technologies for intelligent control and automation are expected to be synthetically applied to the automation of similar systems in nuclear power plants

  15. Pulsed ultrasonic stir welding method

    Science.gov (United States)

    Ding, R. Jeffrey (Inventor)

    2013-01-01

    A method of performing ultrasonic stir welding uses a welding head assembly to include a plate and a rod passing through the plate. The rod is rotatable about a longitudinal axis thereof. In the method, the rod is rotated about its longitudinal axis during a welding operation. During the welding operation, a series of on-off ultrasonic pulses are applied to the rod such that they propagate parallel to the rod's longitudinal axis. At least a pulse rate associated with the on-off ultrasonic pulses is controlled.

  16. Diffusion welding multifilament superconductive composites

    Energy Technology Data Exchange (ETDEWEB)

    Witherell, C.E.

    1978-02-27

    Diffusion welding is shown to be a feasible method for joining composites of niobium-titanium superconductor alloy filaments in a pure copper matrix. Good results were repeatedly obtained using 15/sup 0/ scarf joints welded with externally heated tooling and simple uniaxial compression loading in a conventional hydraulic press. Weld cycles of less than one hour total elapsed time were readily attainable. Through proper closed-die design, it was possible to increase welding pressure sufficiently to use relatively low temperatures to coincide with the optimum aging heat treatment of the superconductor alloy. This temperature limitation is important to retain optimal superconductor properties. Confirming measurements of critical current density of welded joints at 4.2/sup 0/K are in progress. In the welded joints made under optimum conditions, there is bonding of all constituents, including superconductor filaments. Weld tooling which effectively contains the relatively fluid matrix, and resists deformation during repeated weld cycles, is essential to the successful application of the diffusion welding process to these composites.

  17. Weld process study for 316L stainless steel weld metal for liquid helium service

    International Nuclear Information System (INIS)

    This study was conducted to determine the effects of welding process choice on the cryogenic properties of 316L stainless steel welds. Six weldments were impact tested down to 77 K and tensile and fracture toughness tested down to 4 K. The best properties obtained were from a GTA weld, followed by GMA welds; SA welds had the poorest properties. This variation in properties was attributed to the cleanliness of the weld metal, which is dependent on the welding process and parameters selected

  18. Spot Welding Parameter Optimization to Improve Weld Characteristics for Dissimilar Metals

    OpenAIRE

    Aravinthan Arumugam; MohdAmizi Nor

    2015-01-01

    Abstract Resistance spot welding is a process which is widely used in the automotive industry to join steel parts of various thicknesses and types. The current practice in the automotive industry in determining the welding schedule which will be used in the welding process is based on welding table or experiences. This however may not be the optimum welding schedule that will give the best spot weld quality. This work concentrates on the parameter optimization when spot welding steels with di...

  19. Ultrasonic defect detection method for socket welding joint

    International Nuclear Information System (INIS)

    The present invention provides a method of detecting defects over a wide range of a socket weld portion of various kinds of pipelines used, for example, in a nuclear power plant. Namely, an inclined probe is disposed to a jig for detecting defects by ultrasonic waves. This is rotated at least by one turn along the peripheral surface of the material to be detected such as weld tube joints. Defects of weld portion of the material can be detected automatically by using ultrasonic waves during the rotation. The inclined probe for detecting defects by ultrasonic waves comprises a transmission portion having a planar transmittance oscillator disposed to a wedge on the transmission side and a receiving portion comprising a planar receiving oscillator disposed to a wedge on the receiving side. With such a constitution, ultrasonic waves are emitted from the transmission portion to the defect detection portion in the welded portion. If a defect is present, defective echo is reflected to the receiving portion disposed ahead of the probe. Since the defective echo changes depending on the height of the detective portion, the estimation of the height of the defect can be facilitated. (I.S.)

  20. IR-based spot weld NDT in automotive applications

    Science.gov (United States)

    Chen, Jian; Feng, Zhili

    2015-05-01

    utilizes the relative IR intensity change, so that the influence of surface reflection and environment interference can be reduced. Second, for the post-processing inspection, a special induction heater is used to replace the flash lamp, resulting in temperature changes on the order of 10°C. As a result, the signal-to-noise ratio increased by several orders of magnitudes with no surface painting needed, and the inspection results are more accurate and reliable. For real-time inspection, the heat from welding (with temperature exceeding 1000°C) was utilized. Third, "thermal signatures" were identified to uniquely correlate to different weld quality attributes through computational modeling of heat transfer and extensive testing of specially designed ranges of welding conditions. Novel IR image analysis algorithms that automatically and intelligently identify the "thermal signatures" from the IR images and positively determine the weld quality in less than a second were developed.

  1. Welding of Prosthetic Alloys

    OpenAIRE

    Wojciechowska M.; Wołowiec E.; Klimek L.

    2015-01-01

    This paper presents the techniques of joining metal denture elements, used in prosthetic dentistry: the traditional soldering technique with a gas burner and a new technique of welding with a laser beam; the aim of the study was to make a comparative assessment of the quality of the joints in view of the possibility of applying them in prosthetic structures. Fractographic examinations were conducted along with tensile strength and impact strength tests, and the quality of the joints was asses...

  2. Tubing weld cracking test

    International Nuclear Information System (INIS)

    A tubing weld cracking (TWC) test was developed for applications involving advanced austenitic alloys (such as modified 800H and 310HCbN). Compared to the Finger hot cracking test, the TWC test shows an enhanced ability to evaluate the crack sensitivity of tubing materials. The TWC test can evaluate the cracking tendency of base as well as filter materials. Thus, it is a useful tool for tubing suppliers, filler metal producers and fabricators

  3. Steels and welding nuclear

    International Nuclear Information System (INIS)

    This ENEA Data-Base regards mechanical properties, chemical composition and heat treatments of nuclear pressure vessel materials: type A533-B, A302-B, A508 steel plates and forgings, submerged arc welds and HAZ before and after nuclear irradiation. Irradiation experiments were generally performed in high flux material test reactors. Data were collected from international available literature about water nuclear reactors pressure vessel materials embrittlement

  4. Welding of carbon steel vessels without post weld heat treatment

    International Nuclear Information System (INIS)

    The methods available for the repair welding of carbon steel vessels without post weld heat treatment and with particular reference to service in a sour environment have been reviewed. All the available techniques have the common aim of providing adequate properties in the weld metal and heat affected zone without the need for a full post weld stress relief. The heat that is required to provide the necessary metallurgical changes comes, therefore, from an alternate source. The two sources used are heat from suitably placed subsequent weld passes or from localized external heat sources. The technique presently being used by Ontario Hydro to repair vessels subject to sour service utilizes both a high preheat and a welding technique which is designed to temper the heat affected zone formed in the base material by the first weld pass. This technique is an improvement over the 'half bead' techniques given in the ASME X1 code and has been shown to be capable of reducing the hardness of the heat affected zone to an acceptable level. Certain recommendations have been made which could improve control of the technique presently used by Ontario Hydro and provide measurable parameters between procedural tests and the actual weld repairs

  5. Comparison Between Keyhole Weld Model and Laser Welding Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Wood, B C; Palmer, T A; Elmer, J W

    2002-09-23

    A series of laser welds were performed using a high-power diode-pumped continuous-wave Nd:YAG laser welder. In a previous study, the experimental results of those welds were examined, and the effects that changes in incident power and various welding parameters had on weld geometry were investigated. In this report, the fusion zones of the laser welds are compared with those predicted from a laser keyhole weld simulation model for stainless steels (304L and 21-6-9), vanadium, and tantalum. The calculated keyhole depths for the vanadium and 304L stainless steel samples fit the experimental data to within acceptable error, demonstrating the predictive power of numerical simulation for welds in these two materials. Calculations for the tantalum and 21-6-9 stainless steel were a poorer match to the experimental values. Accuracy in materials properties proved extremely important in predicting weld behavior, as minor changes in certain properties had a significant effect on calculated keyhole depth. For each of the materials tested, the correlation between simulated and experimental keyhole depths deviated as the laser power was increased. Using the model as a simulation tool, we conclude that the optical absorptivity of the material is the most influential factor in determining the keyhole depth. Future work will be performed to further investigate these effects and to develop a better match between the model and the experimental results for 21-6-9 stainless steel and tantalum.

  6. Effect of sulfur on weld geometry in pulsed laser welds

    International Nuclear Information System (INIS)

    The primary goal of the present study was to determine whether compositional differences in a surface active element in austenitic stainless steel can alter the geometry of pulsed laser welds. Clearly, much less time is available during pulse laser welding for convection cells to form and influence heat transfer. A two-dimensional heat-transfer code has been developed for pulsed Nd:YAG laser welding that only incorporates heat transfer by conduction for the molten metal. For fluences that do not result in significant evaporation, this code generally yields good predictions of weld geometries, if appropriate corrections are made for surface absorptivity. At higher fluences, significant differences are found between predicted and observed weld pool shapes. This study is a portion of a larger program to determine the causes of these differences. Earlier work has produced direct experimental evidence that convection cells can develop during pulsed laser welding. However, experimental evidence that convection is present during welding is not sufficient to indicate whether convection is a dominant heat transfer mechanism. More recently, modeling of transient two-dimensional Marangoni flow in a pulsed laser weld pool was attempted

  7. Welding advances in power plant construction. Orbital TIG welding

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, T. (Babcock and Wilcox Ltd., Renfrew (UK))

    1984-09-01

    The second in a series of articles outlining areas in which modern welding technology has been applied to the production of components for the power industry. The experience gained in the manufacture of AGR boilers led to work on the development of mechanised orbital TIG welding. Some of this development work, carried out for both fossil fired and nuclear powered stations, is detailed.

  8. Gas Metal Arc Welding. Welding Module 5. Instructor's Guide.

    Science.gov (United States)

    Missouri Univ., Columbia. Instructional Materials Lab.

    This guide is intended to assist vocational educators in teaching an eight-unit module in gas metal arc welding. The module is part of a welding curriculum that has been designed to be totally integrated with Missouri's Vocational Instruction Management System. The following topics are covered in the module: safety and testing, gas metal arc…

  9. Design and Implementation of Software for Resistance Welding Process Simulations

    DEFF Research Database (Denmark)

    Zhang, Wenqi

    2003-01-01

    by engineers and technicians in industry, all of the important parameters in resistance welding are considered and automatically implemented into the software. With the specially designed graphic user interface for Windows, engineers (even without prior knowledge of FEM) can quickly learn and easily operate...... and utilize the software. All industrial users, including welding engineers from DaimlerChrysler, Volkswangen, PSA Peugeot Citroen, VOLVO, Siemens, ABB and so on, have started using the software just after taking a one-day training course. With the user-friendly facilities for flexible geometric design...... of work pieces and electrodes as well as process parameter settings similar to real machine settings, the software has been readily applied in industry for supporting product development and process optimization. After simulation, the dynamic process parameters are graphically displayed. The distributions...

  10. Orbital TIG (GTAW) welding for highest weld joint quality requirements

    International Nuclear Information System (INIS)

    Due to its many advantages orbital TIG (GTAW) welding has become the major standard for mechanised tube and pipe weldings in various industries such as: Semiconductor, food and beverage, dairy and brewery, chemical and bio-/pharmaceutical industry, vessel construction, aerospace, offshore and shipbuilding, heat-exchanger, fossil and nuclear power generation. Today's state-of-the-art technology allows orbital weldings of tubes, pipes, fittings or similar parts from 2,3 mm O.D. up to unlimited sizes (including flat plate). Wall thicknesses from 0,3 mm to 175 mm (narrow groove) can easily be accommodated. For difficult applications like inbore weldings, valve seat repairs or video-controlled remote welds, special equipment can be provided or individually manufactured on customer's demand. (orig.)

  11. Experimental determination of the critical welding speed in high speed MAG welding

    Institute of Scientific and Technical Information of China (English)

    Hu Zhikun; Wu Chuansong

    2008-01-01

    In high speed MAG welding process, some weld formation defects may be encountered. To get good weld quality, the critical welding speed beyond which humping or undercutting weld bead can occur must be known for different conditions. In this research, high speed MAG welding tests were carried out to check out the effects of different factors on the critical welding speed. Through observing the weld bead profiles and the macrographs of the transverse sections of MAG welds, the occurrence tendency of humping weld was analyzed, and the values of critical welding speed were determined under different levels of welding current or voltage, and the effect of shielding gas compositions on the critical welding speed was also investigated.

  12. A control system for uniform bead in fillet arc welding on tack welds

    International Nuclear Information System (INIS)

    Positioning a workpiece accurately and preventing weld distortion, tack welding is often adopted before main welding in the construction of welded structures. However, this tack weld deteriorates the final weld bead profile, so that the grinding process is usually performed for a uniform weld bead profile. In this study, a control system for uniform weld bead is proposed for the fillet arc welding on tack welds. The system consists of GMA welding machine, torch manipulator, laser vision sensor for measuring the tack weld size and the database for optimal welding conditions. Experiments have been performed for constructing the database and for evaluating the control capability of the system. It has been shown that the system has the capability to smooth the bead at the high level of quality

  13. Effects of Fusion Tack Welds on Self-Reacting Friction Stir Welds

    Science.gov (United States)

    Nunes, A. C., Jr.; Pendleton, M. L.; Brooke, S. A.; Russell, C. K.

    2012-01-01

    In order to know whether fusion tack welds would affect the strength of self-reacting friction stir seam welds in 2195-T87 aluminum alloy, the fracture stresses of 144 tensile test coupons cut from 24 welded panels containing segments of friction stir welds were measured. Each of the panels was welded under unique processing conditions. A measure of the effect of the tack welds for each panel was devised. An analysis of the measures of the tack weld effect supported the hypothesis that fusion tack welds do not affect the strength of self-reacting friction stir welds to a 5% level of confidence.

  14. Feasibility study of electron beam welding of spent nuclear fuel canisters

    International Nuclear Information System (INIS)

    A thick walled copper container is presently the prime Swedish alternative for encapsulation of spent nuclear fuel. In order to demonstrate the feasibility of encapsulating high-level nuclear waste in copper containers, a study of electron beam welding of thick copper has been performed. Two copper qualities have been investigated, oxygen free high conductivity (OFHC) copper and phosphorous desoxydized high conductivity copper (PDO). The findings in this study are summarized below. In 100 mm thick copper penetration can be achived at power level of about 75 kW (typically 150 kV x 500 mA) at welding speed of 100 mm/min. The welds in OFHC copper made under these conditions are free from major defects during constant welding conditions. The welds in PDO copper show a microporosity level considerably higher than those in OFHC copper, but no major defects are produced in the welds in PDO copper. In the ending of the weld (ie the fade out) it is still not possible to completely eliminate root and cold-shut defects. A semi-full-scale lid weld has been performed successfully. Automatic ultrasonic C-scan has been shown to be useful in detecting and displaying defects, but some problems still remain with defect sizing. The different speciments of OFHS copper had different attenuation of the ultrasonic signal, forged copper showing a far lower attenuation than hot extruded copper, indicating that attention must be paid in choosing copper that allows accurate ultrasonic testing. Resiudal stresses in the welded zone has been measured and are found to lie in the range -32N/mm2 to +36N/mm2. The peak stress was less than half the assumed value of the proof stress of the fused metal. (authors)

  15. Residual stress reduction in the penetration nozzle weld joint by overlay welding

    International Nuclear Information System (INIS)

    Highlights: • Residual stress reduction in penetration weld nozzle by overlay welding was studied. • The overlay weld can decrease the residual stress in the weld root. • Long overlay welding is proposed in the actual welding. • Overlay weld to decrease residual stress is more suitable for thin nozzle. - Abstract: Stress corrosion cracking (SCC) in the penetration nozzle weld joint endangers the structural reliability of pressure vessels in nuclear and chemical industries. How to decrease the residual stress is very critical to ensure the structure integrity. In this paper, a new method, which uses overlay welding on the inner surface of nozzle, is proposed to decrease the residual stresses in the penetration joint. Finite element simulation is used to study the change of weld residual stresses before and after overlay welding. It reveals that this method can mainly decrease the residual stress in the weld root. Before overlay welding, large tensile residual stresses are generated in the weld root. After overlay weld, the tensile hoop stress in weld root has been decreased about 45%, and the radial stress has been decreased to compressive stress, which is helpful to decrease the susceptibility to SCC. With the increase of overlay welding length, the residual stress in weld root has been greatly decreased, and thus the long overlay welding is proposed in the actual welding. It also finds that this method is more suitable for thin nozzle rather than thick nozzle

  16. Health hazards of welding fumes

    International Nuclear Information System (INIS)

    Even in the twenty -first century , welding is still a common and high skilled occupation. The hazardous agents associated with welding processes are acetylene, carbomonoxide, oxides of nitrogen, ozone, phosgene, tungsten, arsenic, beryllium, cadmium, iron, copper, lead, manganese, nickel, silver,tin and zinc.All welding processes involve the potential hazards for inhalation exposures that may lead to acute or chronic respiratory diseases. According to literature described earlier it has been suggested that welding fumes cause the lung function impairment, obstructive and restrictive,lungs diseases diseases, cough, dyspnea, rhinitis, asthama, pneumoconiosis, carcinoma of the lungs. In additon,welding workers suffer from eye problems like irritation, phtokeratitis, cataract, skin irritation, erythema, petrygium, non-melanosytic skin cancer, malignant melanoma, reduced sperm count , motility and infertility. Most of the studies have been attempted previously to evaluate the effects of weldig fumes.However no cllectively effort illuminating the general effects of welding fumes on differnt organs or systems or both in humans has not been published. Therefore, the aim of this review is to gather the potential toxic effects of welding fumes documented by individual efforts and provides information to community on hazards of welding. (author)

  17. Single mode glass fiber welding

    Science.gov (United States)

    Nelson, M. D.; Fearnehough, H. T.; Goldstein, R.; Goss, W. C.

    1979-01-01

    The electric-arc welding of commercially available single-mode optical fiber has been demonstrated. A mean transmission of 92% and a maximum transmission of 98% are reported for welds of fiber waveguide of 4.5 microns core diameter.

  18. Inverter DC resistance spot welding of magnesium alloy AZ31

    OpenAIRE

    Hwang, I. S.; D. C. Kim; Kang, M. J.

    2011-01-01

    Purpose: The welding lobes of AC resistance spot welding and inverter DC resistance spot welding for the magnesium alloy sheet AZ31 were compared and analyzed.Design/methodology/approach: Using the welding lobe in terms of electrode force, weld time, and weld current which are process variables of the resistance spot welding, optimal welding conditions were determined. The lower limit of the range of the optimal welding condition was decided by minimum shear tension strength for the magnesium...

  19. Laser welding of tailored blanks

    International Nuclear Information System (INIS)

    Laser welding has an increasing role in the automotive industry, namely on the sub-assemblies manufacturing. Several sheet-shape parts are laser welded, on a dissimilar combination of thicknesses and materials, and are afterwards formed (stamped) being transformed in a vehicle body component. In this paper low carbon CO2 laser welding, on the thicknesses of 1,25 and 0.75 mm, formability investigation is described. There will be a description of how the laser welded blanks behave in different forming tests, and the influence of misalignment and undercut on the formability. The quality is evaluated by measuring the limit strain and limit effective strain for the laser welded sheets and the base material, which will be presented in a forming limit diagram. (Author) 14 refs

  20. Reduction of Biomechanical and Welding Fume Exposures in Stud Welding.

    Science.gov (United States)

    Fethke, Nathan B; Peters, Thomas M; Leonard, Stephanie; Metwali, Mahmoud; Mudunkotuwa, Imali A

    2016-04-01

    The welding of shear stud connectors to structural steel in construction requires a prolonged stooped posture that exposes ironworkers to biomechanical and welding fume hazards. In this study, biomechanical and welding fume exposures during stud welding using conventional methods were compared to exposures associated with use of a prototype system that allowed participants to weld from an upright position. The effect of base material (i.e. bare structural beam versus galvanized decking) on welding fume concentration (particle number and mass), particle size distribution, and particle composition was also explored. Thirty participants completed a series of stud welding simulations in a local apprenticeship training facility. Use of the upright system was associated with substantial reductions in trunk inclination and the activity levels of several muscle groups. Inhalable mass concentrations of welding fume (averaged over ~18 min) when using conventional methods were high (18.2 mg m(-3) for bare beam; 65.7 mg m(-3) for through deck), with estimated mass concentrations of iron (7.8 mg m(-3) for bare beam; 15.8 mg m(-3) for through deck), zinc (0.2 mg m(-3) for bare beam; 15.8 mg m(-3) for through deck), and manganese (0.9 mg m(-3) for bare beam; 1.5 mg m(-3) for through deck) often exceeding the American Conference of Governmental Industrial Hygienists Threshold Limit Values (TLVs). Number and mass concentrations were substantially reduced when using the upright system, although the total inhalable mass concentration remained above the TLV when welding through decking. The average diameters of the welding fume particles for both bare beam (31±17 nm) through deck conditions (34±34 nm) and the chemical composition of the particles indicated the presence of metallic nanoparticles. Stud welding exposes ironworkers to potentially high levels of biomechanical loading (primarily to the low back) and welding fume. The upright system used in this study improved exposure

  1. Friction Stir Welding of Aluminum Alloys

    Institute of Scientific and Technical Information of China (English)

    FU Zhi-hong; HE Di-qiu; WANG Hong

    2004-01-01

    Friction stir welding(FSW), a new solid-state welding technology invited in the early 1990s,enables us weld aluminum alloys and titanium alloys etc. The processing of FSW, the microstructure in FSW alloysand the factors influencing weld quality are introduced. The complex factors affecting the properties are researched.

  2. 49 CFR 179.300-9 - Welding.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Welding. 179.300-9 Section 179.300-9... Specifications for Multi-Unit Tank Car Tanks (Classes DOT-106A and 110AW) § 179.300-9 Welding. (a) Longitudinal... fusion welded on class DOT-110A tanks. Welding procedures, welders and fabricators must be approved...

  3. CLASSIFICATION OF PULSE ARC WELDING PROCESSES

    OpenAIRE

    KRAMPIT A.G.; KRAMPIT N.Y.; KRAMPIT M.A.; DMITRIEVA A.V.

    2012-01-01

    Pulse welding processes improve productivity; also they allow welding of thin sheets of metal without penetration. Splashing and expenses for cleaning surfaces from droplets are also reduced. Pulse welding processes have a wholesome effect on seam formation at the expenses of thermal exposure on welding puddle and HAZ.

  4. METHOD AND SYSTEM FOR LASER WELDING

    DEFF Research Database (Denmark)

    2008-01-01

    The invention relates to laser welding of at least two adjacent, abutting or overlapping work pieces in a welding direction using multiple laser beams guided to a welding region, wherein at least two of the multiple laser beams are coupled into the welding region so as to form a melt and at least...

  5. 29 CFR 1910.255 - Resistance welding.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 5 2010-07-01 2010-07-01 false Resistance welding. 1910.255 Section 1910.255 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Welding, Cutting and Brazing § 1910.255 Resistance welding. (a.... Ignitron tubes used in resistance welding equipment shall be equipped with a thermal protection switch....

  6. Weld-cost saving accomplished by replacing single-wire submerged arc welding with triple-wire welding

    OpenAIRE

    Bajcer, Božidar; Umek, I.; Tušek, Janez

    2015-01-01

    A comparison is made of different submerged arc welding processes, that is ones using singlewire, twin-wire and triple-wire electrodes, applied to welding of two webs consisting of L sections 16x90x4100 mm in size. Experimental welding, measurement of welding parameters, calculation of the melting rate, measurement and calculation of shielding flux consumption, a visual examination of the welds made, an analysis of macro sections, and an economic calculation of the respective total cost of th...

  7. Weld testing in the fabrication of large-diameter pipes

    International Nuclear Information System (INIS)

    Fully automatic radiographic testing of cast light metal components is a state of the art technology. The contribution describes its application in weld testing. A new method for evaluating X-rays of welds is presented which were tested using an innovative X-ray camera with maximum spatial resolution and a wide range of grey values. Further, a novel concept for handling test objects significantly shortens testing times. The pipes are not moved longitudinally; instead, the longitudinal motion is made by the X-ray emitter and sensor, which reduces the testing time by up to 30 percent. The specially developed X-ray detector has a sensitive surface of 200 mm x 50 mm with a total of 4.2 million pixels. Neither the evaluation electronics nor the light-sensitive camera chip are exposed to the direct X-radiation so that no damage will occur at photoenergies up to at least 250 keV. Many tests, e.g. according to EN 13068 and EN 462-5, have shown that the image quality in general and especially the local resolution exceeds the specifications of the EN 584 standard on weld testing with X-ray films. The pictures taken by the camera serve as input data for fully automatic evaluation. All stages of image processing implement 16-bit digitalisation depth in order to make use of the high dynamic range of gray value images. This means that in the whole processing chain, there will be no loss of information from downscaling of the gray values. In the first stage of image processing, the gray values are transformed into penetrated material thicknesses in preparation of the measurement of fault length in the direction of incidence at a later stage. In the next stage, external boundaries and the middle of the weld are detected, followed by an adaptive filtering stage. Additionally, information on the accurate location of the weld is transmitted to the control system of the mechanical parts, so that optimum positioning of the weld with respect to the camera is ensured. The adaptive filter

  8. Developments in tube to tubeplate welding

    International Nuclear Information System (INIS)

    The paper deals with the development of a bore welding technique that has been applied in the production of boilers for nuclear power stations. After a description of the weld geometry and the basic welding process, the discussion covers the work necessary to establish the welding parameters and the associated development of welding torches and welding programme controllers. An account is given of some methods that have been employed to overcome certain metallurgical/ welding process problems together with the development of non-destructive testing techniques. (author)

  9. Plasma spot welding of ferritic stainless steels

    International Nuclear Information System (INIS)

    Plasma spot wedding of ferritic stainless steels studied. The study was focused on welding parameters, plasma and shieldings and the optimum welding equipment. Plasma-spot welded overlap joints on a 0.8 mm thick ferritic stainless steel sheet were subjected to a visual examination and mechanical testing in terms of tension-shear strength. Several macro specimens were prepared Plasma spot welding is suitable to use the same gas as shielding gas and as plasma gas , i. e. a 98% Ar/2% H2 gas mixture. Tension-shear strength of plasma-spot welded joint was compared to that of resistance sport welded joints. It was found that the resistance welded joints withstand a somewhat stronger load than the plasma welded joints due to a large weld sport diameter of the former. Strength of both types of welded joints is approximately the same. (Author) 32 refs

  10. Friction stir welding of copper alloys

    Institute of Scientific and Technical Information of China (English)

    Liu Shuhua; Liu Meng; Wang Deqing; Xu Zhenyue

    2007-01-01

    Copper plates,brass plates and copper/brass plates were friction stir welded with various parameters. Experimental results show that the microstructure of the weld is characterized by its much finer grains as contrasted with the coarse grains of parent materials and the heat-affected zones are very narrow. The microhardness of the copper weld is a little higher than that of parent plate. The microhardness of brass weld is about 25% higher than that of parent material. The tensile strength of copper joints increases with increasing welding speed in the test range. The range of parameters to obtain good welds for copper is much wider than that for brass. When different materials were welded, the position of copper plate before welding affected the quality of FSW joints. If the copper plate was put on the advancing side of weld, the good quality of weld could be got under proper parameters.

  11. Automated TIG welding system with visual sensor for repairing nuclear plants

    International Nuclear Information System (INIS)

    An automated TIG welding system has been developed. This system is to be used for repairing nuclear plants, whose work environment is highly radioactive, so should have the automatic self control function and the remote controllable function. For this purpose, the visual sensor, a TV camera and an image processor, is installed and the image processing technique is applied to the all-position TIG welding system. In this system, all controls are made with microprocessors and every necessary information is displayed on the screen of the remote control unit. The excellent performance was obtained as the application of this system to the practical field. (author)

  12. Remote welding and cutting for the JET project

    International Nuclear Information System (INIS)

    There are increasing requirements for joining, separating and rejoining pipes or ducts of various shapes for very demanding applications, such as high vacuum or sodium containment in a radioactive environment. Welding is considered, in these cases, the most reliable joining method. In general the joining and separating operations must be repeated a number of times and motorized carriages automatically guided are envisaged. This solution is often preferred even if personnel access is allowed as it gives reliable results and avoids human errors. This paper discusses the problems encountered and gives viable solutions

  13. Inspection of pipeline girth welds with ultrasonic phased array technique

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A novel automatic ultrasonic system used for the inspection of pipeline girth welds is developed, in which a linear phased array transducer using electronic scan is adopted. Optimal array parameters are determined based on a mathematical model of acoustic field for linear phased array derived from Huygens' principle. The testing method and the system structure are introduced. The experimental results show that the phased array transducer system has the same detectability as that of conventional ultrasonic transducer system, but the system architecture can be simplified greatly, and the testing flexibility and the testing speed can be improved greatly.

  14. Laser Welding Of Finned Tubes Made Of Austenitic Steels

    OpenAIRE

    Stolecki M.; Bijok H.; Kowal Ł.; Adamiec J.

    2015-01-01

    This paper describes the technology of welding of finned tubes made of the X5CrNi1810 (1.4301) austenitic steel, developed at Energoinstal SA, allowing one to get high quality joints that meet the requirements of the classification societies (PN-EN 15614), and at the same time to significantly reduce the manufacturing costs. The authors described an automatic technological line equipped with a Trumph disc laser and a tube production technological process. To assess the quality of the joints, ...

  15. Investigation into Variations of Welding Residual Stresses and Redistribution Behaviors for Different Repair Welding Widths

    International Nuclear Information System (INIS)

    In this study, we investigated the variations in welding residual stresses in dissimilar metal butt weld due to width of repair welding and re-distribution behaviors resulting from similar metal welding (SMW) and mechanical loading. To this end, detailed two-dimensional axi-symmetric finite element (FE) analyses were performed considering five different repair welding widths. Based on the FE results, we first evaluated the welding residual stress distributions in repair welding. We then investigated the re-distribution behaviors of the residual stresses due to SMW and mechanical loads. It is revealed that large tensile welding residual stresses take place in the inner surface and that its distribution is affected, provided repair welding width is larger than certain value. The welding residual stresses resulting from repair welding are remarkably reduced due to SMW and mechanical loading, regardless of the width of the repair welding

  16. DETECTION AND ANALYSIS OF WELD POOL SHAPE FOR CO2 SHORT CIRCUITING ARC WELDING

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A general industrial CCD(ICCD) camera is redesigned to detect the weld pool without arc at the period of short circuiting,so that the interference of arc and spatter during CO2 short circuiting arc welding is eliminated. Through the analysis of weld pool image, both size parameters (such as weld pool area A, weld pool length L1, L2 and weld pool breadth b) and contour parameters (bi which describe the curves of weld pool boundany) ,which could indicate the shape features of weld pool, had been defined to express weld pool information quantitatively. The investigation of the relationships between weld pool shape parameters and welding process parameters may be beneficial to the quality control of CO2 welding.

  17. Sensor integration for robotic laser welding processes

    OpenAIRE

    Iakovou, Dimitrios; Aarts, Ronald; Meijer, Johan

    2005-01-01

    The use of robotic laser welding is increasing among industrial applications, because of its ability to weld objects in three dimensions. Robotic laser welding involves three sub-processes: seam detection and tracking, welding process control, and weld seam inspection. Usually, for each sub-process, a separate sensory system is required. The use of separate sensory systems leads to heavy and bulky tools, in contrast to compact and light sensory systems that are needed to reach sufficient accu...

  18. Collection of arc welding process data

    OpenAIRE

    K. Luksa; Z. Rymarski

    2006-01-01

    Purpose: The aim of the research was to examine the possibility of detecting welding imperfections by recording the instant values of welding parameters. The microprocessor controlled system for real-time collection and display of welding parameters was designed, implemented and tested.Design/methodology/approach: The system records up to 4 digital or analog signals collected from welding process and displays their run on the LCD display. To disturb the welding process artificial disturbances...

  19. Mechanical characterisation and modelling of resistance welding

    OpenAIRE

    Van Rymenant, Patrick

    2011-01-01

    Resistance welding is used very extensively in industry for a wide range of applications. Knowledge and measurement of the dynamic characteristics of resistance welding equipment is important in the design of the equipment and in optimization of welding procedures using finite element software. This is especially true for projection welding where accurate measurements of effective lumped mass and damping of the welding head as well as its maximal acceleration and velocity are required for acc...

  20. Automatic Implantable Cardiac Defibrillator

    Medline Plus

    Full Text Available Automatic Implantable Cardiac Defibrillator February 19, 2009 Halifax Health Medical Center, Daytona Beach, FL Welcome to Halifax Health Daytona Beach, Florida. Over the next hour you' ...

  1. Automatic Payroll Deposit System.

    Science.gov (United States)

    Davidson, D. B.

    1979-01-01

    The Automatic Payroll Deposit System in Yakima, Washington's Public School District No. 7, directly transmits each employee's salary amount for each pay period to a bank or other financial institution. (Author/MLF)

  2. Fundamental Difficulties Associated With Underwater Wet Welding

    Directory of Open Access Journals (Sweden)

    Joshua E. Omajene,

    2014-06-01

    Full Text Available The offshore industries carry out welding activities in the wet environment. It is evident that the wet environments possess difficulties in carrying out underwater welding. Therefore there is the need to improve the quality of weld achieved in underwater welding. This paper investigates the difficulties associated with underwater welding. The objective of this research paper is to identify and analyze the different difficulties in underwater welding so as to make a clear background for further research to identifying the processes of eliminating these difficulties. The major difficulties in underwater welding are the cooling rate of the weld metal and arc stability during underwater wet welding at a higher depth. Methods of decreasing the cooling rate of weld metal and how to achieve arc stability are the major methods of approach. The result of welds achieved in underwater welding will be much improved as compared to air welding if the effects of the difficulties associated with underwater welding are eliminated. This will lead to a more robust welding activities being carried out underwater.

  3. Study of Gasdynamic Effect Upon the Weld Geometry When Concumable Electrode Welding

    Science.gov (United States)

    Chinakhov, D. A.; Grigorieva, E. G.; Mayorova, E. I.

    2016-04-01

    The paper considers the ways of weld geometry controlling when consumable electrode welding under single-jet and double-jet gas shielding. The authors provide comparative results of experimental studies on the effects of shielding gas supply upon the weld geometry in weld joints produced from construction carbon steel 45. It has been established that gas-dynamic effect of the shielding gas has a significant impact upon shaping and weld geometry when consumable electrode welding under double-jet gas shielding.

  4. Automatic Arabic Text Classification

    OpenAIRE

    Al-harbi, S; Almuhareb, A.; Al-Thubaity , A; Khorsheed, M. S.; Al-Rajeh, A.

    2008-01-01

    Automated document classification is an important text mining task especially with the rapid growth of the number of online documents present in Arabic language. Text classification aims to automatically assign the text to a predefined category based on linguistic features. Such a process has different useful applications including, but not restricted to, e-mail spam detection, web page content filtering, and automatic message routing. This paper presents the results of experiments on documen...

  5. 10,170 flawless welds

    CERN Multimedia

    Antonella Del Rosso

    2014-01-01

    The welding of tubes containing the principal current-carrying busbars in the LHC magnets was one of the main activities of the SMACC project. After a year of preparation and another of intense activity in the tunnel, the last weld was completed on Wednesday 14 May. Over 10,170 welds have been inspected and not a single fault has been found.    The welder (above) creates the weld using an orbital welding machine (below) specifically designed for CERN. Each of the eight sectors of the LHC contains around 210 interconnects between the superconducting magnets. Consolidating these interconnections was the SMACC project’s primary objective. One of the last jobs before closing the interconnects is the welding of the M lines: each has a 104 mm diameter and a radial clearance of just 45 mm. In total: 10,170 welds carried out in a single year of activities. A true challenge, which was carried out by a team of 30 highly specialised welders, working under the supervision o...

  6. Random Conformal Weldings

    CERN Document Server

    Astala, K; Kupiainen, A; Saksman, E

    2009-01-01

    We construct a conformally invariant random family of closed curves in the plane by welding of random homeomorphisms of the unit circle. The homeomorphism is constructed using the exponential of $\\beta X$ where $X$ is the restriction of the two dimensional free field on the circle and the parameter $\\beta$ is in the "high temperature" regime $\\beta<\\sqrt 2$. The welding problem is solved by studying a non-uniformly elliptic Beltrami equation with a random complex dilatation. For the existence a method of Lehto is used. This requires sharp probabilistic estimates to control conformal moduli of annuli and they are proven by decomposing the free field as a sum of independent fixed scale fields and controlling the correlations of the complex dilation restricted to dyadic cells of various scales. For uniqueness we invoke a result by Jones and Smirnov on conformal removability of H\\"older curves. We conjecture that our curves are locally related to SLE$(\\kappa)$ for $\\kappa<4$.

  7. Socket welding method

    International Nuclear Information System (INIS)

    Upon joining of metal tubes having a same composition, a metal having a corrosion potential higher by from 50 to 300mV than that of the metal which constitutes the metal tube is disposed at the periphery of the joint portion of the metal tubes in order to improve corrosion resistance of the joint portion of pipelines in a plant such as a nuclear reactor. In a socket joint in which metal tubes having a greater outer diameter than the inner diameter of the other are fitted to each other at the joint portion, more remarkable effect can be obtained. This is because the area of the gap portion is greater than in the case of butt welding. Further, it is preferred that a metal having a corrosion potential greater by from 50 to 300mV than that of the metal tube is interposed at least to a portion of the overlapped portion of the tubes in order to prevent corrosion of the gap portion. Then, a carbon steel pipe weld-joint having sufficiently high resistance to temperature and pressure water SCC can be attained in a BWR reactor water circumstance, and the safety of the BWR can be ensured, as well as the working life of the reactor plant can be attained. (N.H.)

  8. EDF field experience of 182 J-Groove welds on CRDMs and SG channel head nozzles

    International Nuclear Information System (INIS)

    The Reactor Pressure Vessel Head (RPVH) replacement program, which began after a leak occurrence in a vessel head nozzle in Alloy 600 at Bugey Unit 3, was a unique opportunity to perform an extended inspection program on the welds from the decommissioned RPV heads. This paper presents the actual results of this program. More than 800 CRDM J groove welds from 18 decommissioned RPV heads were inspected by automatic dye penetrant testing. Detected indications were characterized by viewing tools specifically developed and in some specific cases, by destructive investigations in hot lab. Some welding defects were observed but no indication corresponding to stress corrosion cracking (SCC) was detected at the welds wet surface nor propagation from welding manufacturing defects, including the weld with the longest operating time on EDF power plants (170 000 h). Very few cases of SCC propagation from Alloy 600 to Alloy 182 are reported. One case of initiation at the weld root pass was observed. From design, the weld root pass (mechanically loaded) of CRDM (Control Rod Drive Mechanism) nozzles is not in contact with primary water and the cracking observed occurred after a through wall cracking of the Alloy 600 tube, enabling primary water to wet the root pass. Concerning the steam generator (SG) drain nozzle, the alloy 182 weld root is directly in contact with primary water. In June 2008, a primary water leakage was suspected on a steam generator bowl drain while conducting a bare metal visual examination during the plant's outage. Dye penetrant testing of the weld and metallographic replica were implemented during the 2008 and 2009 refuelling outages to confirm a leakage by SCC. Manufacturing reports analyses revealed that the drain nozzle weld was repaired and had not been stress relieved during manufacturing. EDF has decided to plug this nozzle and to enforce the maintenance policy for similar components with the same manufacturing specificity. Regarding national and

  9. A method of initial welding position guiding for arc welding robot based on visual servo control

    Institute of Scientific and Technical Information of China (English)

    郭振民; 陈善本; 邱涛; 吴林

    2003-01-01

    In order to solve the visual guiding task of initial welding position for arc welding robot, this paper presents a practice-prone image-based visual servo control strategy without calibration, and we perform validating experiments on a nine-DOF arc welding robot system. Experimental results illustrate presented method has the function to fulfill the task of welding robot initial positioning with certain anti-jamming ability. This method provides a basis for guiding welding gun to initial welding pose with real typical seam's image properties to replace flag block properties, and is a significant exploit to realize visual guiding of initial welding position and seam tracing in robot welding system.

  10. A study of weld quality in ultrasonic spot welding of similar and dissimilar metals

    International Nuclear Information System (INIS)

    Several difficulties are faced in joining thinner sheets of similar and dissimilar materials from fusion welding processes such as resistance welding and laser welding. Ultrasonic metal welding overcomes many of these difficulties by using high frequency vibration and applied pressure to create a solid-state weld. Ultrasonic metal welding is an effective technique in joining small components, such as in wire bonding, but is also capable of joining thicker sheet, depending on the control of welding conditions. This study presents the design, characterisation and test of a lateral-drive ultrasonic metal welding device. The ultrasonic welding horn is modelled using finite element analysis and its vibration behaviour is characterised experimentally to ensure ultrasonic energy is delivered to the weld coupon. The welding stack and fixtures are then designed and mounted on a test machine to allow a series of experiments to be conducted for various welding and ultrasonic parameters. Weld strength is subsequently analysed using tensile-shear tests. Control of the vibration amplitude profile through the weld cycle is used to enhance weld strength and quality, providing an opportunity to reduce part marking. Optical microscopic examination and scanning electron microscopy (SEM) were employed to investigate the weld quality. The results show how the weld quality is particularly sensitive to the combination of clamping force and vibration amplitude of the welding tip.

  11. Plasticity Theory of Fillet Welds

    DEFF Research Database (Denmark)

    Hansen, Thomas

    2005-01-01

    This paper deals with simple methods for calculation of fillet welds based on the theory of plasticity. In developing the solutions the lower-bound theorem is used. The welding material and parts of the base material are subdivided into triangular regions with homogeneous stress fields; thereby a...... safe and statically admissible stress distribution is established. The plasticity solutions are compared with tests carried out at the Engineering Academy of Denmark, Lyngby, in the early nineties, and old fillet weld tests. The new failure conditions are in very good agreement with the yield load...

  12. Novel Process Revolutionizes Welding Industry

    Science.gov (United States)

    2008-01-01

    Glenn Research Center, Delphi Corporation, and the Michigan Research Institute entered into a research project to study the use of Deformation Resistance Welding (DRW) in the construction and repair of stationary structures with multiple geometries and dissimilar materials, such as those NASA might use on the Moon or Mars. Traditional welding technologies are burdened by significant business and engineering challenges, including high costs of equipment and labor, heat-affected zones, limited automation, and inconsistent quality. DRW addresses each of those issues, while drastically reducing welding, manufacturing, and maintenance costs.

  13. Weld bonding of stainless steel

    DEFF Research Database (Denmark)

    Santos, I. O.; Zhang, Wenqi; Goncalves, V.M.;

    2004-01-01

    This paper presents a comprehensive theoretical and experimental investigation of the weld bonding process with the purpose of evaluating its relative performance in case of joining stainless steel parts, against alternative solutions based on structural adhesives or conventional spot-welding. The...... overall assessment of the weld bonding process is made using several commercial adhesives with varying working times under different surface conditions. The quality of the resulting joints is evaluated by means of macroetching observations, tension-shear tests and peel tests. The theoretical investigation...

  14. Review of laser hybrid welding

    DEFF Research Database (Denmark)

    Bagger, Claus

    In this artucle an overview og the hybrid welding process is given. After a short historic overview, a review of the fundamental phenomenon taking place when a laser (CO2 or Nd:YAG) interacts in the same molten pool as a more conventional source of energy, e.g. tungsten in-active gas, plasma, or...... metal inactive gas/metal active gas.This is followed by reports of how the many process parameters governing the hybrid welding process can be set and how the choice of secondary energy source, shielding gas, etc. can affect the overall welding process....

  15. Acoustic field measurements in austenitic welds and dissimilar welds

    International Nuclear Information System (INIS)

    Acoustic field measurements were performed in identical specimen geometries of NPP components, in order to contribute the results to the interpretation of US testing results and evaluation of the testing reliability. With an electrodynamic probe of type T, the sonic fields were scanned by scanning heads at 45 T, 45 L, 60 L, and 70 L. The following selected groups of measured data are discussed in the paper: (a) acoustic fields in a narrow-gap weld and a dissimilar weld; (b) longitudinal sound impact testing of welds for detection of transverse defects; (c) variation of transmissibility of acoustic waves along a welded seam; (d) strength and range of the secondary creep wave; (e) multiply reflected sonic modes. (orig./CB)

  16. Laser welding and post weld treatment of modified 9Cr-1MoVNb steel.

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z. (Nuclear Engineering Division)

    2012-04-03

    Laser welding and post weld laser treatment of modified 9Cr-1MoVNb steels (Grade P91) were performed in this preliminary study to investigate the feasibility of using laser welding process as a potential alternative to arc welding methods for solving the Type IV cracking problem in P91 steel welds. The mechanical and metallurgical testing of the pulsed Nd:YAG laser-welded samples shows the following conclusions: (1) both bead-on-plate and circumferential butt welds made by a pulsed Nd:YAG laser show good welds that are free of microcracks and porosity. The narrow heat affected zone has a homogeneous grain structure without conventional soft hardness zone where the Type IV cracking occurs in conventional arc welds. (2) The laser weld tests also show that the same laser welder has the potential to be used as a multi-function tool for weld surface remelting, glazing or post weld tempering to reduce the weld surface defects and to increase the cracking resistance and toughness of the welds. (3) The Vicker hardness of laser welds in the weld and heat affected zone was 420-500 HV with peak hardness in the HAZ compared to 240 HV of base metal. Post weld laser treatment was able to slightly reduce the peak hardness and smooth the hardness profile, but failed to bring the hardness down to below 300 HV due to insufficient time at temperature and too fast cooling rate after the time. Though optimal hardness of weld made by laser is to be determined for best weld strength, methods to achieve the post weld laser treatment temperature, time at the temperature and slow cooling rate need to be developed. (4) Mechanical testing of the laser weld and post weld laser treated samples need to be performed to evaluate the effects of laser post treatments such as surface remelting, glazing, re-hardening, or tempering on the strength of the welds.

  17. Embrittlement of welds produced by pulsed laser welding

    International Nuclear Information System (INIS)

    Welding through radiation of Nd:Yag laser is characterized by hard thermal deformation cycle under action of which the microstructure changes are obtained. These changes exert considerable influence on the mechanical properties. Experimentally investigated the influence of multipulse action on the butt weld strength at static tension. It was found that by increasing multiplicity equalled to increasing of overlapping factor the destroying stresses are decreased up to some

  18. Utilization of the equipment and program cine- and telerecording complex for the high-frequency steel pipe welding investigation

    Science.gov (United States)

    Konovalov, Nikolai A.; Veselovsky, Vladimir B.; Furmanov, Valeri B.; Kovalenko, Vladimir I.; Lakhno, Nikolay I.; Kovika, Nikolai D.; Novikov, Leonid V.; Scherbina, Vadim N.; Zlydennaya, Lyubov M.

    1995-08-01

    With the aim of technological process automatization and control for high-frequency welding of different diameter pipes, the machine-program complex (APC) was designed. APC gives the opportunity to create the cine- and telerecording of process in production conditions at the mill '159-529' of the Novomoskovsky Tube Rolling Mill, Ukraine). With the help of APC in real functioning mill conditions, the character of flashing zone length changing and the angle of convergence depending on pipe welding speed was investigated. Also the zone of jumpers is defined. The comparison of theoretical and experimental data gave an opportunity to define a welding rate which is optimal for the most qualitative values of welded joints in the range of pipe products of mill '159-529'.

  19. 焊管纵向焊缝实时跟踪系统的研究%Research on the Real-time Longitudinal Weld Tracking System of Welded Pipes

    Institute of Scientific and Technical Information of China (English)

    杜兴吉; 慎建民; 曹志樑; 陆明红; 邵羽

    2013-01-01

    A real-time weld tracking system of arc slide was presented in this paper. The working principle, the major structure ,and the software design of control system were described. The laser sensor is used in this system to measure the position of the weld, and the fuzzy controller with serf-adjusting function is adopted to rectify deviation of the weld. DSP is used as the central controller to produce control signal, which drives to move along weight direction and arc slide, in order to realize real-time weld tracking .The actual application results showed that the system can realize real-time automatic weld tracking of the welding torch,which can meet the requirement of the continuous welded pipe production line.%提出了一种弧形滑架的焊缝实时跟踪系统,对其工作原理、主体结构、控制系统的软件设计等要点进行了阐述.该系统采用激光传感器测量焊缝的位置,并采用一种带修正函数的控制规则自调整模糊控制进行焊缝的纠偏.采用DSP作为核心控制器产生控制信号,驱动焊枪沿高度方向运动并沿弧形导轨转动,实现焊枪对焊缝的实时自动跟踪.生产中的使用结果表明:该系统可以实现焊枪对焊缝的实时自动跟踪,完全满足连续焊管生产线的需要.

  20. MFDC - technological improvement in resistance welding controls

    International Nuclear Information System (INIS)

    Among the various Resistance Welding operations carried out in the production line of a fuel bundle end plug welding is the most critical operation. Welding controllers play a very vital role in obtaining consistent weld quality by regulating and controlling the weld current. Conventional mains synchronized welding controllers are at best capable of controlling the weld current at a maximum speed of the mains frequency. In view of the very short welding durations involved in the various stages of a fuel bundle fabrication, a need was felt for superior welding controllers. Medium Frequency Welding Controllers offer a solution to these limitations in addition to offering other advantages. Medium Frequency power sources offer precise welding current control as they regulate and correct the welding current faster, typically twenty times faster when operated at 1000Hz. An MFDC was employed on one of the welding machines and its performance was studied. This paper discusses about the various advantages of MFDCs with other controllers employed at NFC to end plug welding operation. (author)

  1. Welding for the CRBRP steam generators

    International Nuclear Information System (INIS)

    The rationale for selecting weld design, welding procedures and inspection methods was based upon the desire to obtain the highest reliability welds for the CRBRP steam generators. To assure the highest weld reliability, heavy emphasis was placed on the control of material cleanliness and composition substantially exceeding the requirements of the ASME Code for 2-1/4Cr-1Mo. The high tube/tubesheet weld quality was achieved through close material control, an extensive weld development program and the selection of high reliability welding equipment. A pre-production run involving 300 welds demonstrated the ability of the manufacturing team to work with the methods and tools provided during the development stage. Prior to the initiation of manufacturing, control of the process and equipment was demonstrated by a 52 weld qualification run. Shell and nozzle weld fabrication using TIG, MIG, and submerged arc procedures are also being controlled through precise specifications, including preheat and postheat programs, together with radiography and ultrasonic inspection to ascertain the weld quality desired. Details of the tube/tubesheet welding and shell welding are described and results from the weld testing program are discussed. (author)

  2. Current state of the art of mechanized welding of pipework

    International Nuclear Information System (INIS)

    The various chapters of this contribution deal with: (1) Mechanized welding of joints of pipes, bents and fittings (submerged arc welding; combination of submerged arc and TIG welding, TIG orbital welding, MIG/MAG welding). (2) Nozzle welding. (3) Internal tube welding-thermal sleeves. (4) Tube-in-tubeplate welding. The practical examples discussed cover a range of diameters between 4 and 800 mm, wall thickness between 1 and 60 mm, in austenitic or ferritic tube materials. (MM)

  3. Laser welding of a tube

    International Nuclear Information System (INIS)

    For sleeving PWR steam generator tubes, the welding laser work is made under protection of a primary gas going out by the crossing window of the laser and under a secondary gas flowing axially through the head and the tube

  4. Welding process modelling and control

    Science.gov (United States)

    Romine, Peter L.; Adenwala, Jinen A.

    1993-01-01

    The research and analysis performed, and software developed, and hardware/software recommendations made during 1992 in development of the PC-based data acquisition system for support of Welding Process Modeling and Control is reported. A need was identified by the Metals Processing Branch of NASA Marshall Space Flight Center, for a mobile data aquisition and analysis system, customized for welding measurement and calibration. Several hardware configurations were evaluated and a PC-based system was chosen. The Welding Measurement System (WMS) is a dedicated instrument, strictly for the use of data aquisition and analysis. Although the WMS supports many of the functions associated with the process control, it is not the intention for this system to be used for welding process control.

  5. Welding and Production Metallurgy Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This 6000 square foot facility represents the only welding laboratory of its kind within DA. It is capable of conducting investigations associated with solid state...

  6. Thermomechanical Modelling of Resistance Welding

    DEFF Research Database (Denmark)

    Bay, Niels; Zhang, Wenqi

    2007-01-01

    The present paper describes a generic programme for analysis, optimization and development of resistance spot and projection welding. The programme includes an electrical model determining electric current and voltage distribution as well as heat generation, a thermal model calculating heat...

  7. Laser welding of thermoplastic materials.

    Science.gov (United States)

    Chipperfield, F A; Jones, I A

    2001-06-01

    The capabilities of the three main types of laser are compared and a new technique is introduced, which laser welds plastics using an infrared absorber to create a joint that is almost invisible to the human eye. PMID:11488201

  8. Laser based spot weld characterization

    Science.gov (United States)

    Jonietz, Florian; Myrach, Philipp; Rethmeier, Michael; Suwala, Hubert; Ziegler, Mathias

    2016-02-01

    Spot welding is one of the most important joining technologies, especially in the automotive industry. Hitherto, the quality of spot welded joints is tested mainly by random destructive tests. A nondestructive testing technique offers the benefit of cost reduction of the testing procedure and optimization of the fabrication process, because every joint could be examined. This would lead to a reduced number of spot welded joints, as redundancies could be avoided. In the procedure described here, the spot welded joint between two zinc-coated steel sheets (HX340LAD+Z100MB or HC340LA+ZE 50/50) is heated optically on one side. Laser radiation and flash light are used as heat sources. The melted zone, the so called "weld nugget" provides the mechanical stability of the connection, but also constitutes a thermal bridge between the sheets. Due to the better thermal contact, the spot welded joint reveals a thermal behavior different from the surrounding material, where the heat transfer between the two sheets is much lower. The difference in the transient thermal behavior is measured with time resolved thermography. Hence, the size of the thermal contact between the two sheets is determined, which is directly correlated to the size of the weld nugget, indicating the quality of the spot weld. The method performs well in transmission with laser radiation and flash light. With laser radiation, it works even in reflection geometry, thus offering the possibility of testing with just one-sided accessibility. By using heating with collimated laser radiation, not only contact-free, but also remote testing is feasible. A further convenience compared to similar thermographic approaches is the applicability on bare steel sheets without any optical coating for emissivity correction. For this purpose, a proper way of emissivity correction was established.

  9. Welding of turbine rotor materials.

    OpenAIRE

    Richter, Tomáš

    2012-01-01

    In the Visual - Weld and Sysweld programs, a simplified simulation of the welding process of the turbine rotor made of 27NiCrMoV 15-6 substance was performed. The numerical analysis took place at the equal temperature of preheating and it covered both minimal and maximal percent chemical composition. The simulation proved that the percent deviations of elements in the substance change the speed necessary for reaching of the bainitic structure. Simulation results were verified by a practical e...

  10. Modelling of friction stir welding

    OpenAIRE

    Colegrove, Paul Andrew

    2004-01-01

    This thesis investigates the modelling of friction stir welding (FSW). FSW is a relatively new welding process where a rotating non-consumable tool is used to join two materials through high temperature deformation. The aim of the thesis is the development of a numerical model to improve process understanding and to assist in the design of new tools. The early part of the thesis describes the process, defines the modelling problem and describes why a computational fluid dynamics package (FLUE...

  11. Control of Robotic Welding Cell

    OpenAIRE

    Zabukovec, Andraž

    2013-01-01

    Industrial robots are common place in most modern manufacturing plants because the people running these factories are interested in reducing the plants’ dependence on a human workforce and to simultaneously improve productivity and quality. The thesis presents the operation of a robot welding cell project, which was developed at YASKAWA Ristro d.o.o. for the customer Akrapovič. The sub systems of the robot welding cell will be detailed in the thesis including the following topics; safety c...

  12. Robot automated EMPT sheet welding

    OpenAIRE

    Pasquale, Pablo; Schäfer, Ralph

    2012-01-01

    Many industrial applications require sheet to sheet or sheet to tube joints. The electromagnetic pulse technology is capable to produce these kinds of joints. In literature many examples of sheet to sheet solid state welding between similar and dissimilar metals are presented and analyzed in detail. However, the most of the presented welding applications, which are very focussed on the academic level, are simple specimens for example for tensile test. These specimens are usuall...

  13. Friction Stir Welding Technology: Adapting NASA's Retractable Pin Tool

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    In late 1991, The Welding Institute (TWI), a British research and technology organization, invented and patented a welding process named Friction Stir Welding (FSW). Friction Stir Welding is a highly significant advancement in aluminum welding technology that can produce stronger, lighter, and more efficient welds than any previous process.

  14. Fracture toughness investigation of the welded joints in austenitic piping Du-300 MFCC at Ignalina NPP

    International Nuclear Information System (INIS)

    A study is made into mechanical properties, stress intensity factors, J-R curves of welded joint materials for downcomers of pipelines and for distributing group collectors. The Du 300 of steel 08Kh18N10T, hand and automatic arc welds produced with Sv-04Kh19N11M3 welding wire as well as a heat affected zone (HAZ) metal of this joint are investigated at room and elevated (285 deg C) temperatures. It is shown that all materials studied have lower mechanical properties at 285 deg C in comparison with those at room temperature. The exceptions are represented by the constraint and the modulus of elasticity. Mechanical strength at room temperature is maximal for a well metal and minimal for a HAZ metal. At elevated temperature the strength is maximal for a HAZ metal and minimal for a base metal

  15. Hybrid laser-TIG welding, laser beam welding and gas tungsten arc welding of AZ31B magnesium alloy

    International Nuclear Information System (INIS)

    Welding of AZ31B magnesium alloy was carried out using hybrid laser-TIG (LATIG) welding, laser beam welding (LBW) and gas tungsten arc (TIG) welding. The weldability and microstructure of magnesium AZ31B alloy welded using LATIG, LBW and TIG were investigated by OM and EMPA. The experimental results showed that the welding speed of LATIG was higher than that of TIG, which was caught up with LBW. Besides, the penetration of LATIG doubles that of TIG, and was four times that of LBW. In addition, arc stability was improved in hybrid of laser-TIG welding compared with using the TIG welding alone, especially at high welding speed and under low TIG current. It was found that the heat affect zone of joint was only observed in TIG welding, and the size of grains in it was evidently coarse. In fusion zone, the equiaxed grains exist, whose size was the smallest welded by LBW, and was the largest by TIG welding. It was also found that Mg concentration of the fusion zone was lower than that of the base one by EPMA in three welding processes

  16. Contribution to the study of an on line inspection system for pulsed Nd:YAG laser welding operations

    International Nuclear Information System (INIS)

    This thesis deals with the study of a on line inspection system for pulsed Nd3+:YAG laser welding operations. During a welding operation, laser-material interaction results in the emission of signals (optical, acoustical, electrical, thermal), characteristic of its behavior. On line inspection is based on the hypothesis that the signals evolutions, measured by sensors such as photodiodes, microphones.., may be correlated with the welding defects. Laser weld quality inspection can be done by the machine qualification (before and during welding), and by on line monitoring of the welding operation. The similarity of the signals produced by pulsed lasers (machine or interaction) has led us to develop a specific data acquisition and processing software. Signal processing tools utilization (Fourier and wavelets transforms) in conjunction with classification techniques (stress polytopes), introduces an innovating on line inspection approach. Discriminant parameters determination (signals/defect correlation) becomes thus automatic and non subjective. The developed prototype is not dedicated to the detection of a particular defect because the classification operator is a supervised one and needs a learning phase. lt has been validated on welding defects which are easy to deal with, and then applied to a precise production control at the Nuclear Fabrications and Technology Division of the Valduc Center of the French Atomic Energy Agency. (author)

  17. Welding of Prosthetic Alloys

    Directory of Open Access Journals (Sweden)

    Wojciechowska M.

    2015-04-01

    Full Text Available This paper presents the techniques of joining metal denture elements, used in prosthetic dentistry: the traditional soldering technique with a gas burner and a new technique of welding with a laser beam; the aim of the study was to make a comparative assessment of the quality of the joints in view of the possibility of applying them in prosthetic structures. Fractographic examinations were conducted along with tensile strength and impact strength tests, and the quality of the joints was assessed compared to the solid metal. The experiments have shown that the metal elements used to make dentures, joined by the technique which employs a laser beam, have better strength properties than those achieved with a gas burner.

  18. Welding and reactor safety

    International Nuclear Information System (INIS)

    The high safety requirements which must be demanded of the quality of the welded joints in reactor technique have so far not been fulfilled in all cases. The errors occuring have caused considerable loss of availability and high material costs. They were not, however, so serious that one need have feared any immediate danger to the personnel or to the environment. The safety devices of reactor plants were only called upon in a few cases and to these they responded perfectly. The intensive efforts to complete and improve the specifications are to contribute to that in future, the reactor plants can be counted even more so as one of the safest technical plants ever. (orig./LH)

  19. Status and challenges of dissimilar metal welding

    OpenAIRE

    Simar, Aude; Jimenez Mena, Norberto; Avettand Fénoël, Marie-Noëlle; 10th International Friction Stir Welding Symposium

    2016-01-01

    A review of the status and current challenges of dissimilar metal welding is proposed. By dissimilar metal welding we mean the welding between metals of different primary chemical nature. The FSW scientific research community has been highly focussed on dissimilar metal welding in the past years as lightweighting is a major concern for the transportation (e.g. welding Al to steel, Al to Ti, Al to Mg, etc…) and electrical energy (e.g. welding Cu to Al) industry. Placing the right material at t...

  20. YAG laser welding with surface activating flux

    Institute of Scientific and Technical Information of China (English)

    樊丁; 张瑞华; 田中学; 中田一博; 牛尾诚夫

    2003-01-01

    YAG laser welding with surface activating flux has been investigated, and the influencing factors and mechanism are discussed. The results show that both surface activating flux and surface active element S have fantastic effects on the YAG laser weld shape, that is to obviously increase the weld penetration and D/W ratio in various welding conditions. The mechanism is thought to be the change of weld pool surface tension temperature coefficient, thus, the change of fluid flow pattern in weld pool due to the flux.

  1. Present status and future trend of welding automation under CTMS implementations; CIM kankyoka deno yosetsu no jidoka no genjo to shorai no hoko

    Energy Technology Data Exchange (ETDEWEB)

    Nakata, Y.; Usami, S. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

    1997-12-01

    Mitsui Shipbuilding Company has launched an information system structuring project for shipbuilding and its management since 1993, and plans to complete the Mitsui Advanced Computer Integrated Shipbuilding System (MACISS) within fiscal 1997. This paper introduces its summary and the current status of welding automation. The MACISS consists mainly of expansion of design CAD/CAM, development of a production management system, and unification of related data. It is composed of a design system group, a production management system group, and respective data banks. Its largest purpose is to provide working sites with items of information high in quality and easy to utilize on a timely basis. With regard to welding automation, developments and practical use have been performed on a pipe processing and welding system, a sub-assembly welding robot, a large-assembly welding robot, and automatic bent outer plate welding. Higher efficiency and accuracy may be expected as automatic welding under the above CIM environment, and at the same time, a few points to be attentive in automation may also be enumerated. 2 refs., 9 figs.

  2. Multifunctional Resistance Welding Controller Based on AVR Single Chip Microcomputer%基于AVR单片机的多功能阻焊控制器

    Institute of Scientific and Technical Information of China (English)

    张秀峰; 管功湖; 李祥; 黄晓明; 黄珍锡

    2012-01-01

    According to the control principle of the resistance welding, a multifunctional resistance welding controller using the AVR single chip microcomputer was developed. The main functions of epol welding and seam welding were implied through the design of the hardware circuit and software program, so as to precise control of the welding current and time. The power supply voltage automatic compensation was applied to improve the quality of welding. The multifunctional resistance welding controller was easy to use,and the operation was stable and reliable. It had the functions of automatic fault alarm and single SCR switching on protection.%根据阻焊控制原理,研制以AVR单片机为核心的多功能阻焊控制器.通过软硬件设计,主要实现了点焊、缝焊等焊接功能,做到对焊接时间和焊接电流进行精确控制,同时采取网压自动补偿的措施,以提高焊接质量.多功能阻焊控制器使用方便,运行稳定可靠,具备故障自动报警、单管导通保护等功能.

  3. Laser Welding in Electronic Packaging

    Science.gov (United States)

    2000-01-01

    The laser has proven its worth in numerous high reliability electronic packaging applications ranging from medical to missile electronics. In particular, the pulsed YAG laser is an extremely flexible and versatile too] capable of hermetically sealing microelectronics packages containing sensitive components without damaging them. This paper presents an overview of details that must be considered for successful use of laser welding when addressing electronic package sealing. These include; metallurgical considerations such as alloy and plating selection, weld joint configuration, design of optics, use of protective gases and control of thermal distortions. The primary limitations on use of laser welding electronic for packaging applications are economic ones. The laser itself is a relatively costly device when compared to competing welding equipment. Further, the cost of consumables and repairs can be significant. These facts have relegated laser welding to use only where it presents a distinct quality or reliability advantages over other techniques of electronic package sealing. Because of the unique noncontact and low heat inputs characteristics of laser welding, it is an ideal candidate for sealing electronic packages containing MEMS devices (microelectromechanical systems). This paper addresses how the unique advantages of the pulsed YAG laser can be used to simplify MEMS packaging and deliver a product of improved quality.

  4. Automatic Program Development

    DEFF Research Database (Denmark)

    Automatic Program Development is a tribute to Robert Paige (1947-1999), our accomplished and respected colleague, and moreover our good friend, whose untimely passing was a loss to our academic and research community. We have collected the revised, updated versions of the papers published in his...... honor in the Higher-Order and Symbolic Computation Journal in the years 2003 and 2005. Among them there are two papers by Bob: (i) a retrospective view of his research lines, and (ii) a proposal for future studies in the area of the automatic program derivation. The book also includes some papers by...... members of the IFIP Working Group 2.1 of which Bob was an active member. All papers are related to some of the research interests of Bob and, in particular, to the transformational development of programs and their algorithmic derivation from formal specifications. Automatic Program Development offers a...

  5. Experimental study on activating welding for aluminum alloys

    Institute of Scientific and Technical Information of China (English)

    Huang Yong; Fan Ding

    2005-01-01

    TIG welding and EB welding for aluminum alloy 3003 were carried out to study the effects of activating flux on weld penetration of activating welding for aluminum alloys. SiO2 was used as the activating flux. It is found that, SiO2 can increase the weld penetration and decrease the weld width of FBTIG when the flux gap is small. For A-TIG welding and EB welding with focused mode, the weld penetrations and the weld widths increase simultaneously. SiO2 has little effect on the weld penetration and weld width of EB welding with defocused mode. It is believed that, change of surface tension temperature gradient is not the main mechanism of SiO2 improving weld penetration of activating welding for aluminum alloys.

  6. Automatic utilities auditing

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Colin Boughton [Energy Metering Technology (United Kingdom)

    2000-08-01

    At present, energy audits represent only snapshot situations of the flow of energy. The normal pattern of energy audits as seen through the eyes of an experienced energy auditor is described. A brief history of energy auditing is given. It is claimed that the future of energy auditing lies in automatic meter reading with expert data analysis providing continuous automatic auditing thereby reducing the skill element. Ultimately, it will be feasible to carry out auditing at intervals of say 30 minutes rather than five years.

  7. Automatic Camera Control

    DEFF Research Database (Denmark)

    Burelli, Paolo; Preuss, Mike

    2014-01-01

    Automatically generating computer animations is a challenging and complex problem with applications in games and film production. In this paper, we investigate howto translate a shot list for a virtual scene into a series of virtual camera configurations — i.e automatically controlling the virtual...... camera. We approach this problem by modelling it as a dynamic multi-objective optimisation problem and show how this metaphor allows a much richer expressiveness than a classical single objective approach. Finally, we showcase the application of a multi-objective evolutionary algorithm to generate a shot...

  8. Automatic text summarization

    CERN Document Server

    Torres Moreno, Juan Manuel

    2014-01-01

    This new textbook examines the motivations and the different algorithms for automatic document summarization (ADS). We performed a recent state of the art. The book shows the main problems of ADS, difficulties and the solutions provided by the community. It presents recent advances in ADS, as well as current applications and trends. The approaches are statistical, linguistic and symbolic. Several exemples are included in order to clarify the theoretical concepts.  The books currently available in the area of Automatic Document Summarization are not recent. Powerful algorithms have been develop

  9. A comparison of the physics of Gas Tungsten Arc Welding (GTAW), Electron Beam Welding (EBW), and Laser Beam Welding (LBW)

    Science.gov (United States)

    Nunes, A. C., Jr.

    1985-01-01

    The physics governing the applicability and limitations of gas tungsten arc (GTA), electron beam (EB), and laser beam (LB) welding are compared. An appendix on the selection of laser welding systems is included.

  10. The effect of post-welding conditions in friction stir welds: From weld simulation to Ductile Failure

    DEFF Research Database (Denmark)

    Hattel, Jesper Henri; Nielsen, Kim Lau; Tutum, Cem Celal

    2012-01-01

    possible effect of the post-welding conditions when subjecting a friction stir weld to loading transverse to the weld line. The numerical model of the friction stir welded joint, employs a step-wise modeling approach to combine an in-situ weld simulation with a post-welding failure analysis. Using the...... commercial software ANSYS, a thermo-mechanical model is employed to predict the thermally induced stresses and strains during welding, while an in-house finite element code is used to study the plastic flow localization and failure in a subsequent structural analysis. The coupling between the two models is...... prior to plastic flow localization was observed, with a substantial influence on the specimen elongation at the onset of localization and thereby failure. This influence is, however, shown to be strongly affected by the applied boundary conditions. Specimens cut from the welded plate, transverse to the...

  11. Upgraded HFIR Fuel Element Welding System

    Energy Technology Data Exchange (ETDEWEB)

    Sease, John D [ORNL

    2010-02-01

    The welding of aluminum-clad fuel plates into aluminum alloy 6061 side plate tubing is a unique design feature of the High Flux Isotope Reactor (HFIR) fuel assemblies as 101 full-penetration circumferential gas metal arc welds (GMAW) are required in the fabrication of each assembly. In a HFIR fuel assembly, 540 aluminum-clad fuel plates are assembled into two nested annular fuel elements 610 mm (24-inches) long. The welding process for the HFIR fuel elements was developed in the early 1960 s and about 450 HFIR fuel assemblies have been successfully welded using the GMAW process qualified in the 1960 s. In recent years because of the degradation of the electronic and mechanical components in the old HFIR welding system, reportable defects in plate attachment or adapter welds have been present in almost all completed fuel assemblies. In October 2008, a contract was awarded to AMET, Inc., of Rexburg, Idaho, to replace the old welding equipment with standard commercially available welding components to the maximum extent possible while maintaining the qualified HFIR welding process. The upgraded HFIR welding system represents a major improvement in the welding system used in welding HFIR fuel elements for the previous 40 years. In this upgrade, the new inner GMAW torch is a significant advancement over the original inner GMAW torch previously used. The innovative breakthrough in the new inner welding torch design is the way the direction of the cast in the 0.762 mm (0.030-inch) diameter aluminum weld wire is changed so that the weld wire emerging from the contact tip is straight in the plane perpendicular to the welding direction without creating any significant drag resistance in the feeding of the weld wire.

  12. Laser spot welding of electronic micro parts

    Science.gov (United States)

    Ostendorf, Andreas; Temme, Thorsten; Zeadan, Jeihad

    2004-10-01

    This paper deals with parameter optimization and online monitoring of laser spot welding (LSW). Using Nd:YAG laser, a wide range of experiments regarding the welding process have been carried out for both successful and failed welds. The typical failures appearing during packaging of surface mounted devices (SMDs) on flexible printed circuits (FPC) include gaps, a loss of connection between the welded components, and damage of the printed circuit boards. A flip-flop device called SO16 and lead frames as two components of widely used SMDs were packaged on FPCs in the experiments. The reproducibility of the weld quality for SO16 (FeNi) is greater than for lead frames (CuFe2P); this points out the difficulties appearing during copper or copper alloy welding. However, a correlation between the weld quality and the detected emission signals recorded during the weld process has been found for both components. The detected signals of the optical process emission for successful welds depict identical characterisics which are divided into three relevant signal phases. Changes in the signal characteristics, especially in these phases, imply information about the weld quality. While monitoring the welding processes for both components are possible, the detected signals for SO16 are less sensitive to process variations compared to those for lead frames. Based on spectral analysis, the intensity of the detected emission due to SO16 welding is slightly higher than the intensity due to lead frames welding.

  13. Automatic flaw detecting device for reactor pressure vessel

    International Nuclear Information System (INIS)

    The device of the present invention is used for detecting flaws in welded portions of a pressure vessel while running along a track formed at the circumference of the pressure vessel, by which cables for transmitting collected data to a detection chamber can be laid around easily. Namely, a power supply conductor for supplying electric power to the device and a leakage coaxial cable as a receiving antenna are disposed to the tracks along the longitudinal direction. A connection terminal is disposed to the automatic flaw detecting device to be in contact with the power supply conductor. In addition, an oscillator is disposed for transmitting signals collected by a supersonic probe to the leakage coaxial cable by way of a transmission antenna. Then, since cables drawn from the automatic flaw detecting device are used only for transporting air and water to the flaw detection portion, the cables can be laid easily to improve the operationability. (I.S.)

  14. Comparative study on CO2 laser overlap welding and resistance spot welding for galvanized steel

    International Nuclear Information System (INIS)

    Highlights: ► Laser welding and resistance welding are respectively researched on galvanized steel. ► The characteristics of the two kinds of welding methods are systematically analyzed. ► Laser welding joint have much more compact structures and smaller heat-affected zones. ► The tensile-shear performance of laser weld joint is superior under certain condition. ► Laser welding test pieces has greater resistance to deformation and corrosion. -- Abstract: The CO2 laser overlap welding and the resistance spot welding are respectively investigated on DC56D galvanized steel used for auto body. The characteristics of the two types of welding methods are systematically analyzed in terms of the weld molding, tensile-shear performance, microstructure, hardness, and corrosion resistance of welding joint. The results show that, the fusion widths of the upper and lower surface are almost the same for the resistance welding joint, and the weld nugget is surrounded by the heat-affected zone. While the laser welding joint belongs to deep penetration welding, the weld fusion width presents wide at the top and narrow at the bottom, and the heat-affected zone is situated on both sides of the weld pool. Compared with resistance spot welding joint, laser welding joints have much more ultrafine microstructures, much smaller heat-affected zones, as well as greater resistance to deformation and corrosion. In addition, the tensile-shear performance of laser weld joints is superior to that of resistance welding joints under certain conditions.

  15. Development of technique for laser welding of biological tissues using laser welding device and nanocomposite solder.

    Science.gov (United States)

    Gerasimenko, A; Ichcitidze, L; Podgaetsky, V; Ryabkin, D; Pyankov, E; Saveliev, M; Selishchev, S

    2015-08-01

    The laser device for welding of biological tissues has been developed involving quality control and temperature stabilization of weld seam. Laser nanocomposite solder applied onto a wound to be weld has been used. Physicochemical properties of the nanocomposite solder have been elucidated. The nature of the tissue-organizing nanoscaffold has been analyzed at the site of biotissue welding. PMID:26738200

  16. An initial study on welding procedure using tandem MIG welding of high strength aluminum alloy

    Institute of Scientific and Technical Information of China (English)

    林三宝; 刚铁; 杨春利; 崔洪波

    2004-01-01

    The high-speed camera system and data acquisition system of welding parameters were created in tandem MIG welding of high strength aluminum alloy. The experiments were carried out in order to obtain the photos of droplet transfer under different welding parameters in pulsed mode. The droplet transfer mode of "one pulse one droplet" becomes the preferred selection during welding process because of its stable procedure and sound weld form. The parameter ranges for corresponding transfer mode were experimentally achieved, among which the stable droplet transfer mode of "one pulse one droplet" can be realized. These efforts brave the way for control weld heat input and weld formation in the future.

  17. Diffusion welding in air. [solid state welding of butt joint by fusion welding, surface cleaning, and heating

    Science.gov (United States)

    Moore, T. J.; Holko, K. H. (Inventor)

    1974-01-01

    Solid state welding a butt joint by fusion welding the peripheral surfaces to form a seal is described along with, autogenetically cleaning the faying or mating surfaces of the joint by heating the abutting surfaces to 1,200 C and heating to the diffusion welding temperature in air.

  18. Effect of Laser Welding Parameters on Formation of NiTi Shape Memory Alloy Welds

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2014-01-01

    Full Text Available In this work experimental trials of welding of NiTi flat plates with 2.0 mm thickness were conducted using a 4.5 kW continuous wave (CW Nd:YAG laser. The influences of laser output power, welding speed, defocus amount and side-blow shielding gas flow rate on the morphology, welding depth and width, and quality of the welded seam were investigated. Meanwhile, the effects of heat input on the mechanical and functional properties of welded joints were studied. The results show that laser welding can take better formation in NiTi alloys. The matching curves with laser power and welding speed affecting different formation of welds were experimentally acquired, which can provide references for laser welding and engineering application of NiTi alloy. The heat input has obvious effects on the ultimate tensile strength (UTS and shape memory behavior of the welded joints.

  19. Effect of weld reinforcement on axial plastic buckling of welded steel cylindrical shells

    Institute of Scientific and Technical Information of China (English)

    Chu-lin YU; Zhi-ping CHEN; Ji WANG; Shun-juan YAN; Li-cai YANG

    2012-01-01

    The effect of weld reinforcement on axial plastic buckling of welded steel cylindrical shells is investigated through experimental and numerical buckling analysis using six welded steel cylindrical shell specimens.The relationship between the amplitude of weld reinforcement and the axial plastic buckling critical load is explored.The effect of the material yield strength and the number of circumferential welds on the axial plastic buckling is studied.Results show that circumferential weld reinforcement represents a severe imperfect form of axially compressed welded steel cylindrical shells and the axial plastic buckling critical load decreases with the increment of the mean amplitude of circumferential weld reinforcement.The material yield strength and the number of circumferential welds are found to have no significant effect on buckling waveforms; however,the axial plastic buckling critical load can be decreased to some extent with the increase of the number of circumferential welds.

  20. Predicting effects of diffusion welding parameters on welded joint properties by artificial neural network

    Institute of Scientific and Technical Information of China (English)

    刘黎明; 祝美丽; 牛济泰; 张忠典

    2001-01-01

    The static model for metal matrix composites in diffusion welding was established by means of artificial neural network method. The model presents the relationship between weld joint properties and welding parameters such as welding temperature, welding pressure and welding time. Through simulating the diffusion welding process of SiCw/6061Al composite, the effects of welding parameters on the strength of welded joint was studied and optimal technical parameters was obtained. It is proved that this method has good fault-tolerant ability and versatility and can overcome the shortage of the general experiment. The established static model is in good agreement with the actual welding process, so it becomes a new path for studying the weldability of new material.

  1. Method and instrument for judging welded joints

    International Nuclear Information System (INIS)

    This non-destructive method works in real time and evaluates the mechanical stress waves going out from the weld. The invention is described using a laser welding instrument as an example. (RW) 891 RW/RW 892 MKO

  2. 49 CFR 192.225 - Welding procedures.

    Science.gov (United States)

    2010-10-01

    ... qualified under section 5 of API 1104 (incorporated by reference, see § 192.7) or section IX of the ASME... § 192.7) to produce welds meeting the requirements of this subpart. The quality of the test welds...

  3. 49 CFR 195.214 - Welding procedures.

    Science.gov (United States)

    2010-10-01

    ... accordance with welding procedures qualified under Section 5 of API 1104 or Section IX of the ASME Boiler and Pressure Vessel Code (incorporated by reference, see § 195.3) . The quality of the test welds used...

  4. Advances in welding science and technology

    International Nuclear Information System (INIS)

    Over the years, welding has been more of an art than a science, but in the last few decades major advances have taken place in welding science and technology. With the development of new methodologies at the crossroads of basic and applied sciences, enormous opportunities and potential exist to develop a science-based design of composition, structure, and properties of welds with intelligent control and automation of the welding processes. In the last several decades, welding has evolved as an interdisciplinary activity requiring synthesis of knowledge from various disciplines and incorporating the most advanced tools of various basic applied sciences. A series of international conferences and other publications have covered the issues, current trends and directions in welding science and technology. In the last few decades, major progress has been made in (i) understanding physical processes in welding, (ii) characterization of microstructure and properties, and (iii) intelligent control and automation of welding. This paper describes some of these developments

  5. Recent developments in underwater repair welding

    International Nuclear Information System (INIS)

    As nuclear plants age and reactor internal components begin to show increased evidence of age-related phenomena such as corrosion and fatigue, interest in the development of cost-effective mitigation and repair remedies grows. One technology currently receiving greater development and application program focus is underwater welding. Underwater welding, as used herein, is the application of weld metal to a substrate surface that is wet, but locally dry in the immediate area surrounding the welding torch. The locally dry environment is achieved by the use of a mechanical device that is specifically designed for water exclusion from the welding torch, surface to be welded, and the welding groove. This paper will explore recent developments in the use of underwater welding as a mitigation and repair technique. (author)

  6. Alloy 800 welding experience at UKAEA Springfields

    International Nuclear Information System (INIS)

    Investigatins into the welding of alloy 800 at the Reactor Fuel Element Laboratories, Springfields, commenced about three years ago following an extended development programme on tube to tube plate welding of low alloy and stainless steels for the Prototype Fast Reactor. The techniques and approach developed for critical fuel element welding applications had proved equally suitable for the precision welding requirements on the much heavier sections of heat exchangers. It had been demonstrated that the same control of weld quality and profile could be achieved with consistency and the permissible range of critical parameters could be readily defined. Because of this, development work was continued to include other materials, such as alloy 800, which might be of potential use. The tungsten inert gas (T.I.G.) arc welding process is used, and the equipment, including the control system, is described. Tube to tube-plate welding, and tube to tube butt welding, are discussed. (author)

  7. Novel characterization of welding fumes

    International Nuclear Information System (INIS)

    Complete text of publication follows. The lung deposition of welding fume comprised of a large number of primary nanoparticles, occurs predominantly in the alveolar region. The particle size distribution of welding fumes is an important factor determining the bioaccessibility of metal components and the hazard potential of pro-inflammatory effects driven largely by soluble and insoluble transition metals. Several techniques are frequently used for determining the particle size distribution of different welding fumes. A scanning mobility particle sizer (SMPS) offers the opportunity of temporal particle-size distribution measurements and to follow the changes in particle number concentration, a transmission electron microscope (TEM) is capable of visualizing the individual particle morphology and measuring the particle size of primary particles. Are the results obtained with these two techniques comparable? To answer this question welding fumes were generated by different welding methods and examined by a SMPS in the range of 10 to 487 nanometers. The SMPS instrument measures the size distribution of fine particles by separating particles based on electrical-mobility. Particles of a selected size are detected optically, using a detection technology in which small particle visibility is enhanced by growing the particles in a condensing butyl alcohol vapour. Samples were collected on TEM grids made of nickel, copper and silicon for primary particle characterization by TEM. Particle size distributions with both analytical techniques were determined. The most obvious features of the TEM analysis were that the primary welding fume particles had a tendency to form chainlike agglomerates in case of all welding, and almost no individual primary particles were found. It is quite unclear how these agglomerates are detected by the SMPS. An important finding of the chemical analysis of the particles by TEM was that the larger particles contained cores of more volatile components

  8. Automatic Dance Lesson Generation

    Science.gov (United States)

    Yang, Yang; Leung, H.; Yue, Lihua; Deng, LiQun

    2012-01-01

    In this paper, an automatic lesson generation system is presented which is suitable in a learning-by-mimicking scenario where the learning objects can be represented as multiattribute time series data. The dance is used as an example in this paper to illustrate the idea. Given a dance motion sequence as the input, the proposed lesson generation…

  9. Automatic Complexity Analysis

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    1989-01-01

    One way to analyse programs is to to derive expressions for their computational behaviour. A time bound function (or worst-case complexity) gives an upper bound for the computation time as a function of the size of input. We describe a system to derive such time bounds automatically using abstract...

  10. Thermal treatment of dissimilar steels' welded joints

    Science.gov (United States)

    Nikulina, A. A.; Denisova, A. S.; Gradusov, I. N.; Ryabinkina, P. A.; Rushkovets, M. V.

    2016-04-01

    In this paper combinations of chrome-nickel steel and high-carbon steel, produced by flash butt welding after heat treatment, are investigated. Light and electron microscopic studies show that the welded joints after heat treatment have a complex structure consisting of several phases as initial welded joints. A martensite structure in welded joints after thermal treatment at 300... 800 °C has been found.

  11. Laser welding of advanced high strength steels

    OpenAIRE

    Ahmed, Essam Ahmed Ali

    2011-01-01

    This research work focuses on characterization of CO2 laser beam welding (LBW) of dual phase (DP) and transformation induced plasticity (TRIP) steel sheets based on experimental, numerical simulation and statistical modeling approaches. The experimental work aimed to investigate the welding induced-microstructures, hardness, tensile properties and formability limit of laser welding butt joints of DP/DP, TRIP/TRIP and DP/TRIP steel sheets under different welding speeds. The effects of shieldin...

  12. Welding of high manganese- and carbon steels

    International Nuclear Information System (INIS)

    Technology and conditions of welding of high manganese and carbon steel by a resistance welding technique using an intermediate part are developed. Austenitic chromium-nickel 12Kh18N10T steel is chosen as a material of the intermediate part. The recommended welding conditions insure a high quality of the weld joint in terms of metal structure and its mechanical properties. It is the basic metal of the joint that fractures under mechanical testing

  13. Managing distortion in welded structures using FEM

    OpenAIRE

    Ghanadi, Mehdi

    2013-01-01

    Welding as high productive joining method is widely employed in automotive, aerospace and shipbuilding industries. In practice, welding distortion brings about undesirable effects on production accuracy, appearance and strength of welded components. Thus, in order to increase the productivity and decrease the cost of the product, prediction and analysis of welding deformation are key factors in industrial context. Distortion of a structure can be measured experimentally; whilst in case of lar...

  14. Qualification of electron beam welding procedure

    International Nuclear Information System (INIS)

    In electron beam welding, the problem of the procedure qualification is quite special. The main results obtained are presented namely: the influence of the welding equipment used, the finding of significant testing to be taken into consideration for the process qualification. The experiments have been made using two different welding machines. Two materials have been selected (austenitic stainless steel and ferritic steel) and two welding positions (flat position and horizontal-vertical position) investigated

  15. Bronchial reactions to exposure to welding fumes.

    OpenAIRE

    Contreras, G R; Chan-Yeung, M.

    1997-01-01

    OBJECTIVES: To study the airway response and its mechanism to welding fumes in six welders with respiratory symptoms. METHODS: Methacholine and welding challenge tests were carried out. The concentration of welding fumes during the exposure test was measured. On two subjects who developed bronchoconstricition to welding challenge, additional tests were carried out including prick, patch, and inhalation challenges with metal salt solutions. RESULTS: Three subjects developed immediate bronchial...

  16. Experimental determination of the weld penetration evolution in keyhole plasma arc welding

    Institute of Scientific and Technical Information of China (English)

    Hu Qingxian; Wu Chuansong; Zhang Yuming

    2007-01-01

    Keyhole plasma arc welding experiments are conducted to measure the weld geometry and penetration at different moments during the initial phase from igniting arc to quasi-steady state. Indirect information on keyhole formation and evolution in plasma arc welding can be extracted based on the weld macrophotograph at cross section. It has laid foundation to verify the mathematical models of keyhole plasma arc welding.

  17. Prospect of Friction Stir Welding in Automobile TWB Production as Alternative of Laser Welding

    OpenAIRE

    Shahriyar, Mohammed Hasan

    2012-01-01

    In some situation, commonly used welding processes (Laser and Seam welding) in car industry do not produce mechanically acceptable Tailor Welded Blanks (TWB). The present work explores whether the Friction Stir welding (FSW) can overcome three major drawbacks of Laser welding process to produce TWB for car industry. It is identified that some types of Aluminum to Aluminum joints, some combinations of High Strength Steels (HSS) to HSS joints and Steel to Aluminum joints are troublesome to prod...

  18. Welding Polarity Effects on Weld Spatters and Bead Geometry of Hyperbaric Dry GMAW

    Institute of Scientific and Technical Information of China (English)

    XUE Long; WU Jinming; HUANG Junfen; HUANG Jiqiang; ZOU Yong; LIU Jian

    2016-01-01

    Welding polarity has influence on welding stability to some extent, but the specific relationship between welding polarity and weld quality has not been found, especially under the hyperbaric environment. Based on a hyperbaric dry welding experiment system, gas metal arc welding(GMAW) experiments with direct current electrode positive(DCEP) and direct current electrode negative(DCEN) operations are carried out under the ambient pressures of 0.1 MPa, 0.4 MPa, 0.7 MPa and 1.0 MPa to find the influence rule of different welding polarities on welding spatters and weld bead geometry. The effects of welding polarities on the weld bead geometry such as the reinforcement, the weld width and the penetration are discussed. The experimental results show that the welding spatters gradually grow in quantity and size for GMAW with DCEP, while GMAW with DCEN can produce fewer spatters comparatively with the increase of the ambient pressure. Compared with DCEP, the welding current and arc voltage waveforms for DCEN is more stable and the distribution of welding current probability density for DCEN is more concentrated under the hyperbaric environment. When the ambient pressure is increased from 0.1 MPa to 1.0 MPa, the effects of welding polarities on the reinforcement, the weld width and the penetration are as follows: an increase of 0.8 mm for the weld reinforcement is produced by GMAW with DCEN and 1.3 mm by GMAW with DCEP, a decrease of 7.2 mm for the weld width is produced by DCEN and 6.1 mm by DCEP; and an increase of 3.9 mm for the penetration is produced by DCEN and 1.9 mm by DCEP. The proposed research indicates that the desirable stability in the welding procedure can be achieved by GMAW with DCEN operation under the hyperbaric environment.

  19. Real time evaluation of weld quality in narrow groove pipe welding

    OpenAIRE

    Marmelo, Patricia C.

    2012-01-01

    With the growth in pipeline installations all over the world, there is a great demand for highly productive and robust welding systems. Mechanised pipe welding has been developed over the last 50 years and the present focus is towards development of automated pipeline welding systems. Pipeline welding automation is aimed at reducing costs and improving the installation quality. To attain fully automated pipe welding systems there is a need to rely on sensors and controls system...

  20. Characterization of duplex stainless steel weld metals obtained by hybrid plasma-gas metal arc welding

    OpenAIRE

    Koray Yurtisik; Suha Tirkes; Igor Dykhno; C. Hakan Gur; Riza Gurbuz

    2013-01-01

    Despite its high efficiency, autogenous keyhole welding is not well-accepted for duplex stainless steels because it causes excessive ferrite in as-welded duplex microstructure, which leads to a degradation in toughness and corrosion properties of the material. Combining the deep penetration characteristics of plasma arc welding in keyhole mode and metal deposition capability of gas metal arc welding, hybrid plasma - gas metal arc welding process has considered for providing a proper duplex mi...

  1. Influence of Welding With Two-Jet Gas Shielding On the Shaping of a Welding Joint

    Science.gov (United States)

    Chinakhov, D. A.; Chinakhova, E. D.; Grichin, S. V.; Gotovschik, Y. M.

    2016-04-01

    The author considers gas-dynamic influence upon microhardness and weld configuration of single-pass welds from steel 30HGSA when welding with consumable electrode under double-jet shielding. The relations to the chosen controlled welding parameters (Q, L, I) are developed and the controlling influence of the gas-dynamic affect of dynamic shield gas jet over formation of welds from alloy-treated steel 30HGSA is determined.

  2. Three-dimensional simulator and welding application system; Sanjigen simulator to yosetsu jidoka eno tekiyo jirei

    Energy Technology Data Exchange (ETDEWEB)

    Inaba, K. [Mitsui Engineering and Shipbuilding Co. Ltd., Tokyo (Japan)

    1998-08-01

    This paper introduces application examples of three-dimensional simulator, CimStation, to the automation of welding. The CimStation can be used for the design of robots, layout design of work cells, and construction of operation programs. The utilization procedures are illustrated. Shape modeling of robots and works can be conducted using CAD function. Models of automatized equipment can be made in the work cells. Relative position between the modeled equipment and object in the work cell can be determined by the interference check function. Operation programs are constructed by specifying work points, welding speed and welding time. Relative position of the model and absolute position of the equipment are corrected. The operation program is converted into operation data. Some application examples are illustrated. Off-line teaching using the simulator is applied to machining of curve panel plates using 3D laser machining unit. The robot program is made in the design of spot welding and assembly process. Layout design is conducted for arc welding. 6 figs.

  3. Characterization of the stress-strain behaviour in type 316 stainless steel welded joints

    International Nuclear Information System (INIS)

    The monotonic and cyclic stress-strain behaviours of type 316 stainless steel weld metal and Heat Affected Zone (HAZ), obtained by the automatic tungsten inert gas process, were investigated at 550 and 650 deg C and compared with base material data. Uniform gage specimens were machined from longitudinal welds executed on a 4-mm. thick, 2 inch tube and tested in the as welded condition. Owing to the small extension of the HAZ in these joints, an artificial HAZ was obtained in base material specimens by a simulation technique based on micro-hardness and grain size values. Cyclic tests were conducted under diametral control at constant strain rate of 10-3 s-1, according to the incremental-step method. Test data from several specimens were correlated with the Ramberg-Osgood analytic relationship by the root-mean-square technique. Results indicate that the cyclic stress response of the HAZ and especially of the weld material are significantly lower than that of the base metal so that plastic strain accumulation is very likely to occur at the highest service loads. The related work is part of a research program aimed at checking the reliability of the analysis techniques employed for design of LMFBR welded components. (author)

  4. Development of a new tube-to-tubesheet welding type for FBR's heat exchangers

    International Nuclear Information System (INIS)

    The intermediate heat exchanger for exchanging heat between primary and secondary sodium and the steam generator are required to guarantee the performance and the reliability of construction over long term under the environment of high temperature sodium peculiar to a FBR. With the increase of power output of FBR plants, the number of heating tubes and the size of tube plates of the intermediate heat exchangers of shell and tube type increase. In order to improve the reliability and the production process of the tube to tube plate welding, a new method was developed, according to which heating tubes are inserted into tube plate holes by about their thickness, and the welding of perfect penetration is carried out internally with an automatic TIG welder. At the same time, in order to confirm the reliability of the welded joints by this method, the tests for evaluating the strength for short time and long term were carried out. It was confirmed that the satisfactory performance of the welded joints was able to be obtained, and the method would be applicable to actual heat exchangers. As for the nondestructive inspection of welded joints, the radiographic method was established, and ultrasonic and eddy current flaw detection methods are being developed now. (Kako, I.)

  5. Three-Dimensional Coaxial Weld Monitoring

    Science.gov (United States)

    Gordon, Stephen S.

    1989-01-01

    Optical system for coaxial-viewing welding torch enables perception or measurement of depth. Light from welding area passes through beam splitter into two optical trains forming two images, each viewed along line making small angle with axis of torch. Two lines of sight intersect at weld pool. Parallax between two views provides sensation of depth over entire field view.

  6. 30 CFR 77.408 - Welding operations.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Welding operations. 77.408 Section 77.408 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH... for Mechanical Equipment § 77.408 Welding operations. Welding operations shall be shielded and...

  7. 46 CFR 154.665 - Welding procedures.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Welding procedures. 154.665 Section 154.665 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS... Construction § 154.665 Welding procedures. Welding procedure tests for cargo tanks for a design...

  8. Multipass welding of nuclear reactor components - computations

    International Nuclear Information System (INIS)

    The finite element method is used to compare different welding procedures. The simulations are compared with measurements. Two different geometries and two different welding procedures are evaluated. It is found that a narrow gap weld gives smaller tensile residual axial stresses on the inside of the pipe. This is believed to reduce the risk for intergranular stress corrosion cracking

  9. Friction welding thermal and metallurgical characteristics

    CERN Document Server

    Yilbas, Bekir Sami

    2014-01-01

    This book provides insight into the thermal analysis of friction welding incorporating welding parameters such as external, duration, breaking load, and material properties. The morphological and metallurgical changes associated with the resulting weld sites are analysed using characterization methods such as electron scanning microscope, energy dispersive spectroscopy, X-ray Diffraction, and Nuclear reaction analysis.

  10. Fracture toughness of stainless steel welds

    International Nuclear Information System (INIS)

    The effects of temperature, composition and weld-process variations on the fracture toughness behavior for Types 308 and 16-8-2 stainless steel (SS) welds were examined using the multiple-specimen J/sub R/-curve procedure. Fracture characteristics were found to be dependent on temperature and weld process but not on filler material. Gas-tungsten-arc (GTA) welds exhibited the highest fracture toughness, a shielded metal-arc (SMA) weld exhibited an intermediate toughness and submerged-arc (SA) welds yielded the lowest toughness. Minimum-expected fracture properties were defined from lower-bound J/sub c/ and tearing modulus values generated here and in previous studies. Fractographic examination revealed that microvoid coalescence was the operative fracture mechanism for all welds. Second phase particles of manganese silicide were found to be detrimental to the ductile fracture behavior because they separated from the matrix during the initial stages of plastic straining. In SA welds, the high density of inclusions resulting from silicon pickup from the flux promoted premature dimple rupture. The weld produced by the SMA process contained substantially less manganese silicide, while GTA welds contained no silicide inclusions. Delta ferrite particles present in all welds were substantially more resistant to local failure than the silicide phase. In welds containing little or no manganese silicide, delta ferrite particles initiated microvoid coalescence but only after extensive plastic straining

  11. Experimental and simulated strength of spot welds

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Bennedbæk, Rune A.K.; Larsen, Morten B.;

    2014-01-01

    Weld strength testing of single spots in DP600 steel is presented for the three typical testing procedures, i.e. tensile-shear, cross-tension and peel testing. Spot welds are performed at two sets of welding parameters and strength testing under these conditions is presented by load-elongation cu...

  12. Electron beam welding of austenitic stainless steel

    International Nuclear Information System (INIS)

    Austenitic stainless steel is used for liquid metal-cooled fast breeder reactors with operating temperature of about 550 deg C, because its elevated temperature properties are excellent and the results of use are abundant. The welded joints in LMFBRs require high degree of safety, and the application of electron beam welding is studied to make welding joints of high quality. When the inelastic deformation in a certain limit is allowed as prescribed in the ASME Code, Case 1592, the elevated temperature properties of the welded joints of structures are particularly important. The materials tested were 10 mm thick plates of SUS 304, SUS 316 and SUS 321 steels, and 150 kV - 40 mA electron beam welder was employed. The method of welding was one side, one pass Uranami welding, and first, the appropriate welding conditions were decided. Elevated temperature tensile test was carried out on the parent materials and welded joints by electron beam welding and coated arc welding. Creep rupture test and elevated temperature fatigue test were also carried out. In EB-welded austenitic stainless steel, delta ferrite is scattered finely in austenite, and its quantity is very small and less than 1.5%. The tensile strength and 0.2% proof stress of EB-welded joints are almost same as those of parent materials. The creep rupture and fatigue properties of the joints are also close to those of parent materials. (Kako, I.)

  13. Corrosion Properties of Laser Welded Stainless Steel

    DEFF Research Database (Denmark)

    Weldingh, Jakob; Olsen, Flemmming Ove

    1997-01-01

    In this paper the corrosion properties of laser welded AISI 316L stainless steel are examined. A number of different welds has been performed to test the influence of the weld parameters of the resulting corrosion properties. It has been chosen to use the potential independent critical pitting...

  14. Welding device inside a small diameter tube

    International Nuclear Information System (INIS)

    The orbital welding tool is supported in a socket at the end of a flexible tube. A motor rotating the head is placed in a casing fixed to the other end of the flexible tube and rotates the welding tool by the intermediary of a flexible transmission. A second flexible tube fixed to the casing permits the translation of the welding tool

  15. Circumferential TIG welding of zircaloy flow tubes

    International Nuclear Information System (INIS)

    Reactivity control mechanism consists of 10 mtr. long zircaloy flow tubes (inner and outer) with components welded to hold the absorber elements. These components were welded by the plug welding process and supplied to Madras Atomic Power Station (MAPS) and Narora Atomic Power Station (NAPS). In view of the in-service problem faced in Rajasthan Atomic Power Station (RAPS), the spot welds were modified to circumferential TIG welding with additional reinforcement. Development work was taken up for additional reinforcement with screws and circumferential TIG welding of these assemblies. The additional reinforcement with screws and spot welds were critically examined and the job was taken up and successfully completed at Narora site for Narora Atomic Power Projects (NAPP-II). Several trials were conducted for circumferential TIG welding of zircaloy. Since zircaloy is highly reactive in nature, good shielding with inert gas should be ensured to avoid weld contamination due to oxygen and nitrogen. The strength, microstructural and radiographical requirements were examined with different parameters of welding such as weld current, feed, inert gas flow and weld configuration. The strength and other requirements were achieved meeting stringent specifications and assemblies for KAPP-I were successfully completed and despatched. (author). 7 figs

  16. 49 CFR 179.200-10 - Welding.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Welding. 179.200-10 Section 179.200-10... Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.200-10 Welding. (a) All joints... W (IBR, see § 171.7 of this subchapter). Welding procedures, welders and fabricators shall...

  17. 49 CFR 195.224 - Welding: Weather.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding: Weather. 195.224 Section 195.224 Transportation Other Regulations Relating to Transportation (Continued) PIPELINE AND HAZARDOUS MATERIALS SAFETY... PIPELINE Construction § 195.224 Welding: Weather. Welding must be protected from weather conditions...

  18. 49 CFR 179.220-10 - Welding.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Welding. 179.220-10 Section 179.220-10... Specifications for Non-Pressure Tank Car Tanks (Classes DOT-111AW and 115AW) § 179.220-10 Welding. (a) All joints... of this subchapter). Welding procedures, welders, and fabricators shall be approved. (b)...

  19. 49 CFR 179.100-9 - Welding.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Welding. 179.100-9 Section 179.100-9... Specifications for Pressure Tank Car Tanks (Classes DOT-105, 109, 112, 114 and 120) § 179.100-9 Welding. (a) All..., appendix W (IBR, see § 171.7 of this subchapter). Welding procedures, welders and fabricators shall...

  20. Resistance welding equipment manufacturing capability for exports

    International Nuclear Information System (INIS)

    Indian Pressurised Heavy Water Reactor (PHWR) fuel bundle is fully welded and is unique in its design. Appendage welding, end closure welding, and end plate welding is carried out using resistance welding technique. Out of many joining processes available, resistance-welding process is reliable, environment friendly and best suitable for mass production applications. Nuclear Fuel Complex (NFC), an industrial unit is established in Hyderabad, under the aegis of the Dept of Atomic Energy to manufacture fuel for Pressurised Heavy Water Reactors. From inception, NFC has given importance for self-reliance and indigenization with respect to manufacturing process and equipment. Sintering furnaces, centreless grinders, appendage-welding machines, end-closure welding equipment and end-plate welding equipments, which were initially imported, are either indigenized or designed and manufactured in house. NFC has designed, manufactured a new appendage-welding machine for manufacturing 37 element fuel bundles. Recently NFC has bagged an order from IAEA through international bidding for design, manufacture, supply, erection and commissioning of end-closure welding equipment. The paper gives in detail the salient features of these welding equipment. (author)

  1. 46 CFR 154.660 - Pipe welding.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Pipe welding. 154.660 Section 154.660 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR... § 154.660 Pipe welding. (a) Pipe welding must meet Part 57 of this chapter. (b) Longitudinal butt...

  2. 49 CFR 179.400-11 - Welding.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Welding. 179.400-11 Section 179.400-11...-11 Welding. (a) Except for closure of openings and a maximum of two circumferential closing joints in... subchapter). (d) Each welding procedure, welder, and fabricator must be approved....

  3. Laser welding of plastics: theory and experiments

    Science.gov (United States)

    Atanasov, Peter A.

    1995-10-01

    The process of laser welding of plastics is studied theoretically and experimentally. Welding of cylindrical parts made from polycarbonate and polypropylene is presented as examples. A good correspondence between theoretical and experimental results is found. Some practical aspects of laser welding of plastics are given.

  4. Welding Using Chilled-Inert-Gas Purging

    Science.gov (United States)

    Mcgee, William F.; Rybicki, Daniel J.

    1995-01-01

    Report describes study of fusion welding using chilled inert gas. Marked improvement shown in welding of aluminum using chilled helium gas. Chilling inert gas produces two additional benefits: 1) creation of ultradense inert atmosphere around welds; 2) chilled gas cools metal more quickly down to temperature at which metals not reactive.

  5. 波纹管焊缝跟踪检测技术%Tracking measurement technology for welding seam of bellows

    Institute of Scientific and Technical Information of China (English)

    段振云; 蒋卫卫; 赵文辉; 任仲伟

    2011-01-01

    In order to improve the seam quality and welding speed for bellows, an automatic welding technique with real-time tracking measurement system was presented according to the welding seam characteristics of bellows.The infrared laser sensor was used for performing the non-contact and real-time detection of welded joint center.The profile data of welding seam was transmitted by IEEE-1384 fire wire communication.Through pre-processing the data and combining with least square method, the coordinates of welding points were storaged and forecasted.Then the data was transmitted to the moving control card to control the welding gun.The experimental results show that the present tracking measurement technology for welding seam is stable and reliable, and is effective for improving the welding quality and efficiency of bellows.%为了提高波纹管焊缝的焊接质量和焊接速度,根据波纹管焊缝的特点,提出了一种实时跟踪检测波纹管焊缝的自动焊接技术.采用红外激光传感器对焊缝中心进行非接触式实时检测,通过1394火线通讯传输焊缝轮廓数据,经焊缝数据点预处理后结合最小二乘法直线拟合原理对焊点坐标进行存储与预测,再向运动控制卡发送数据控制焊枪跟踪焊接.实验结果表明,此焊缝跟踪检测技术稳定可靠,能够有效地提高波纹管的焊接质量和生产效率.

  6. Laser weld process monitoring and control using chromatic filtering of thermal radiation from a weld pool

    International Nuclear Information System (INIS)

    The application of high power Nd: YAG lasers for precision welding in industry has been growing quite fast these days in diverse areas such as the automobile, the electronics and the aerospace industries. These diverse applications also require the new developments for the precise control and the reliable process monitoring. Due to the hostile environment in laser welding, a remote monitoring is required. The present development relates in general to weld process monitoring techniques, and more particularly to improved methods and apparatus for real-time monitoring of thermal radiation of a weld pool to monitor a size variation and a focus shift of the weld pool for weld process control, utilizing the chromatic aberration of focusing lens or lenses. The monitoring technique of the size variation and the focus shift of a weld pool is developed by using the chromatic filtering of the thermal radiation from a weld pool. The monitoring of weld pool size variation can also be used to monitor the weld depth in a laser welding. Furthermore, the monitoring of the size variation of a weld pool is independent of the focus shift of a weld pool and the monitoring of the focus shift of a weld pool is independent of the size variation of a weld pool

  7. Laser weld process monitoring and control using chromatic filtering of thermal radiation from a weld pool

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Cheol Jung; Kim, Min Suk; Baik, Sung Hoon; Chung, Chin Man

    2000-06-01

    The application of high power Nd: YAG lasers for precision welding in industry has been growing quite fast these days in diverse areas such as the automobile, the electronics and the aerospace industries. These diverse applications also require the new developments for the precise control and the reliable process monitoring. Due to the hostile environment in laser welding, a remote monitoring is required. The present development relates in general to weld process monitoring techniques, and more particularly to improved methods and apparatus for real-time monitoring of thermal radiation of a weld pool to monitor a size variation and a focus shift of the weld pool for weld process control, utilizing the chromatic aberration of focusing lens or lenses. The monitoring technique of the size variation and the focus shift of a weld pool is developed by using the chromatic filtering of the thermal radiation from a weld pool. The monitoring of weld pool size variation can also be used to monitor the weld depth in a laser welding. Furthermore, the monitoring of the size variation of a weld pool is independent of the focus shift of a weld pool and the monitoring of the focus shift of a weld pool is independent of the size variation of a weld pool.

  8. Pipeline welding with Flux Cored and Metal Cored Wire; Soldagem de dutos com processos Arame Tubular e de Alma Metalica

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Ubirajara Pereira da [ITW Soldagem Brasil Miller-Hobart, Sao Paulo, SP (Brazil)

    2003-07-01

    Different welding process like SMAW, Semi-Automatic FCAW Gas-shielded and Self-shielded and Mechanized GMAW-MAG with Solid Wire are suggested to weld Transmission Pipelines. Presently, the largest extensions of Transmission Pipelines under construction, are in China like Lines West-East, Zong-Wu, Shan-Jing Fuxian and some others, totalizing about 8.000 km, and all using Semi-Automatic Self Shielded Flux Cored Arc Welding Process. Also, several papers and magazines that covers Transmission Pipelines Welding, not frequently mention Operational aspects of the process and some other variables like environment and site geography. This presentation intends to cover some of the Operational aspects of the Flux Cored Arc Welding and GMAW-Metal Cored in order to give sufficient information for Construction, Engineering, Projects e Contractors so they can evaluate these Process against the SMAW or even Mechanized Systems, considering the Operation Factor, Efficiency and Deposition Rate. We will not cover operational details of the GMAW Mechanized Systems but only suggest that be evaluated the possibility to replace the GMAW-Solid Wire by the GMAW-Metal Cored Wire. (author)

  9. Contamination and solid state welds.

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Bernice E.

    2007-05-01

    Since sensitivity to contamination is one of the verities of solid state joining, there is a need for assessing contamination of the part(s) to be joined, preferably nondestructively while it can be remedied. As the surfaces that are joined in pinch welds are inaccessible and thus provide a greater challenge, most of the discussion is of the search for the origin and effect of contamination on pinch welding and ways to detect and mitigate it. An example of contamination and the investigation and remediation of such a system is presented. Suggestions are made for techniques for nondestructive evaluation of contamination of surfaces for other solid state welds as well as for pinch welds. Surfaces that have good visual access are amenable to inspection by diffuse reflection infrared Fourier transform (DRIFT) spectroscopy. Although other techniques are useful for specific classes of contaminants (such as hydrocarbons), DRIFT can be used most classes of contaminants. Surfaces such as the interior of open tubes or stems that are to be pinch welded can be inspected using infrared reflection spectroscopy. It must be demonstrated whether or not this tool can detect graphite based contamination, which has been seen in stems. For tubes with one closed end, the technique that should be investigated is emission infrared spectroscopy.

  10. Microstructure modeling in weld metal

    International Nuclear Information System (INIS)

    Since microstructure development in the weld metal region is controlled by various physical processes, there is a need for integrated predictive models based on fundamental principles to describe and predict the effect of these physical processes. These integrated models should be based on various tools available for modeling microstructure development in a wide variety of alloy systems and welding processes. In this paper, the principles, methodology, and future directions of modeling thermochemical reactions in liquid, solidification, and solid state transformations are discussed with some examples for low-alloy steel, stainless steel, and Ni-base superalloy. Thermochemical deoxidation reactions in liquid low-alloy steel lead to oxide inclusion formation. This inclusion formation has been modeled by combining principles of ladle metallurgy and overall transformation kinetics. The model's comparison with the experimental data and the ongoing work on coupling this inclusion model with the numerical models of heat transfer and fluid flow are discussed. Also, recent advances in theoretical and physical modeling of the solidification process are reviewed with regard to predicting the solidification modes, grain structure development, segregation effects, and nonequilibrium solidification in welds. The effects of solid state phase transformations on microstructure development and various methods of modeling these transformations are reviewed. Successful models, based on diffusion-controlled growth and plate growth theories, on microstructure development in low-alloy steel and stainless steel weld metals are outlined. This paper also addresses the importance of advanced analytical techniques to understand the solid state transformation mechanisms in welds

  11. Laser strobe weld pool vision for robotic arc welding

    International Nuclear Information System (INIS)

    This paper describes continuing work in arc light suppression in the viewing of weld pool via a stroboscopic video system. In addition to refining the basic technique, the system has been extended in ways that will enhance its applicability to robotics and the adaptive control of welding processes, as well as provide a general diagnostic tool for welding production and research. In summary, the stroboscopic video technique uses a night vision image intensifier tube to gate video image with the illumination of the weld pool area supplied by a very strong repetitively pulsed light source such as a xenon flash lamp or a laser. Although the average optical power of illuminator is much lower than that of the arc, the peak power is much greater and the gated image almost completely suppresses the light of the arc. The image is then focused into a CCD camera whose video output is conventional and can be viewed in real time, analyzed line-by-line, or recorded on a standard video cassette recorder. The present work has branched in several directions. Two laser illumination sources have been developed. One is a pulsed ultraviolet laser with substantially more peak power than the xenon lamp, used for illuminating the rather difficult video environment found in the high-current GMA welding of aluminum plate. This laser has been mated with an optical fiber which delivers its light to the welding torch, a technique amenable to robotic applications. The other laser illumination source is based on infrared laser diodes; while much less powerful than other pulsed lasers, they are cheap, compact, rugged, and require little auxiliary equipment to operate

  12. Automatic Defect Detection in X-Ray Images Using Image Data Fusion

    Institute of Scientific and Technical Information of China (English)

    TIAN Yuan; DU Dong; CAI Guorui; WANG Li; ZHANG Hua

    2006-01-01

    Automatic defect detection in X-ray images is currently a focus of much research at home and abroad. The technology requires computerized image processing, image analysis, and pattern recognition. This paper describes an image processing method for automatic defect detection using image data fusion which synthesizes several methods including edge extraction, wave profile analyses, segmentation with dynamic threshold, and weld district extraction. Test results show that defects that induce an abrupt change over a predefined extent of the image intensity can be segmented regardless of the number, location, shape, or size. Thus, the method is more robust and practical than the current methods using only one method.

  13. Electron Beam Welding to Join Gamma Titanium Aluminide Articles

    Science.gov (United States)

    Kelly, Thomas Joseph (Inventor)

    2008-01-01

    A method is provided for welding two gamma titanium aluminide articles together. The method includes preheating the two articles to a welding temperature of from about 1700 F to about 2100 F, thereafter electron beam welding the two articles together at the welding temperature and in a welding vacuum to form a welded structure, and thereafter annealing the welded structure at an annealing temperature of from about 1800 F to about 2200 F, to form a joined structure.

  14. Welding of zircaloy tubes for fuel rods fabrication

    International Nuclear Information System (INIS)

    The TIG process form welding zircaloy tube-end plug to fabricate UO2 pellet fuel rods is presented. The zircaloy tube is used as weld by welding zircaloy end-plugs inserted into ends. The technical aspects of this welding process, necessary equipment, and weld properties are discussed. The main problems involved with this type of weld and the nondestructive and destructive weld quality controls are emphasized. (Author)

  15. Statistical analysis of welding industry of South Korea

    OpenAIRE

    Kim, C.; Kang, M; Bae, S

    2009-01-01

    Purpose: This paper represents the current status of welding industry of South Korea - how much the welding industry accounts for in monetary terms in the manufacturing industry of South Korea.Design/methodology/approach: We classify welding industry into welding equipment industry and materials & the welding engineering sub-industry. To decide the portion of the welding industry in other engineering industry, we adopt the Welding-Related Expenditures, Investments, and Productivity Measuremen...

  16. Selection of arc welding parameters of micro alloyed HSLA steel

    OpenAIRE

    M. Dunđer; Ž. Ivandić; Samardžić, I.

    2008-01-01

    In order to ensure performance reliability of a welded product, its quality has to be ensured by proper setting of welding parameters and welding cycle. A quality weld – a weld with no manufacturing, structural or geometric flaws, i.e. with necessary mechanical properties - is achieved only by correct parameter definition and adherence. The knowledge of various effects and relations between welding parameters and their repetition enable an optimal choice of welding parameters.

  17. Selection of arc welding parameters of micro alloyed HSLA steel

    Directory of Open Access Journals (Sweden)

    M. Dunđer

    2008-10-01

    Full Text Available In order to ensure performance reliability of a welded product, its quality has to be ensured by proper setting of welding parameters and welding cycle. A quality weld – a weld with no manufacturing, structural or geometric flaws, i.e. with necessary mechanical properties - is achieved only by correct parameter definition and adherence. The knowledge of various effects and relations between welding parameters and their repetition enable an optimal choice of welding parameters.

  18. Estimation of weld nugget temperature by thermography method in resistance projection welding process

    International Nuclear Information System (INIS)

    In the Pressurized Heavy Water Reactor (PHWR) fuel manufacturing, zirconium alloy appendages like spacer and bearing pads are welded to the thin wall zirconium alloy fuel tubes by using resistance projection welding process. Out of many joining processes available, resistance-welding process is reliable, environment friendly and best suitable for mass production applications. In the fuel assembly, spacer pads are used to get the required inter-element spacing and Bearing pads are used to get the required load-bearing surface for the fuel assembly. Performance of the fuel assembly in the reactor is greatly influenced by these weld joint's quality. Phase transformation from α to β phase is not acceptable while welding these tiny appendages. At present only destructive metallography test is available for this purpose. This can also be achieved by measuring weld nugget temperature where in the phase transformation temperature for zirconium alloy material is 853oC. The temperature distribution during resistance welding of tiny parts cannot be measured by conventional methods due to very small space and short weld times involved in the process. Shear strength, dimensional accuracy and weld microstructures are some of the key parameters used to measure the quality of appendage weld joints. Weld parameters were optimized with the help of industrial experimentation methodology. Individual projection welding by split electrode concept, and during welding on empty tube firm support is achieved on inner side of the tube by using expandable pneumatic mandrel. In the present paper, an attempt was made to measure the weld nugget temperature by thermography technique and is correlated with standard microstructures of zirconium alloy material. The temperature profiles in the welding process are presented for different welding conditions. This technique has helped in measuring the weld nugget temperature more accurately. It was observed that in the present appendage welding

  19. Automatic indexing, compiling and classification

    International Nuclear Information System (INIS)

    A review of the principles of automatic indexing, is followed by a comparison and summing-up of work by the authors and by a Soviet staff from the Moscou INFORM-ELECTRO Institute. The mathematical and linguistic problems of the automatic building of thesaurus and automatic classification are examined

  20. The effect of axial force and contact angle on the welded area of plastic tube welded by ultrasonic welding

    Science.gov (United States)

    Thinvongpituk, C.; Bootwong, A.; Watanabe, Y.

    2010-03-01

    This study was aimed to apply the use of ultrasonic welding to weld round plastic tubes. The ultrasonic welding machine was designed to be able to work with a normal ultrasonic welding transducer by rotating the tube while it is being welded. The specimens used in this study were round plastic tubes (PMMA) with diameter of 35 mm and 2 mm thickness. End of each tube was machined to have angle of 2.8, 3.8 and 5.7 degree in order to create contact angle at the interface. The specimens were welded with frequency of 28 kHz and tube rotational speeds of 25 rpm, 45 rpm and 100 rpm. The axial force was applied to the tube in order to enhance the quality of joint. The experimental result revealed that the modified ultrasonic welding machine can generate the welded area around the circumference of tube. It was found that the axial force and contact angle have some effect to the quality of joint. The contact angle of 2.8/2.8 provided highest welded area compared to 3.8/3.8 and 5.7/5.7 degree of contact angle. In addition, the axial force between 80 N - 120 N provided high value of welded area. The pattern of welded area is also presented and discussed in the paper.

  1. TIG welding phenomenon and properties of welds in welding atmospheres with various oxygen and nitrogen partial pressures. Pt. 1. Study on welding of zirconium alloy tubing. 3

    International Nuclear Information System (INIS)

    The purpose of this study is to investigate the influence of extremely low levels of oxygen and nitrogen partial pressure, PO2 and PN2 in TIG welding atmospheres on the welding phenomenon and properties of welds of zirconium alloy tubing. In TIG welding of Zircaloy-2 tubing in welding atmospheres with various PO2 and PN2, the arc voltages were measured and the properties of welds (surface discoloration, oxygen and nitrogen contents) were examined. Although definite arc voltage change is not observed at welding in ≤4.1 Pa of PO2, a significant arc voltage drop with increase of PN2 is observed at welding in 0.4-16.9 Pa of PN2, and oxygen appears to inhibit this arc voltage drop. The surface of weld metal and heat affected zone (HAZ) in the atmosphere of 0.1 Pa of PO2 and 0.4 Pa of PN2 remains bright. The surface discoloration is observable slightly on weld metal and HAZ in the atmosphere of 1.1 Pa of PO2, and with increase of PO2 the initial straw color becomes darker until it gets partially blue. No surface discoloration is observable on weld metals and HAZ in the atmospheres of PN2 ≤ 16.9 Pa with 0.1 Pa of PO2. The nitrogen content [N] in the weld metal increases linearly with increase of √PN2, and the increasing rate of [N] in inner part of weld metal is lower than that of [N] in outer part. The oxygen content [O] in the weld metal increases linearly with increase of √PO2 and shows same relations as [N], although the values of [O] in the weld metals fluctuate more than [N]. (author)

  2. Study of Mechanical Properties and Characterization of Pipe Steel welded by Hybrid (Friction Stir Weld + Root Arc Weld) Approach

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Yong Chae [ORNL; Sanderson, Samuel [MegaStir Technologies LLC; Mahoney, Murray [Consultant; Wasson, Andrew J [ExxonMobil, Upstream Research Company (URC); Fairchild, Doug P [ExxonMobil, Upstream Research Company (URC); Wang, Yanli [ORNL; Feng, Zhili [ORNL

    2015-01-01

    Friction stir welding (FSW) has recently attracted attention as an alternative construction process for gas/oil transportation applications due to advantages compared to fusion welding techniques. A significant advantage is the ability of FSW to weld the entire or nearly the entire wall thickness in a single pass, while fusion welding requires multiple passes. However, when FSW is applied to a pipe or tube geometry, an internal back support anvil is required to resist the plunging forces exerted during FSW. Unfortunately, it may not be convenient or economical to use internal backing support due to limited access for some applications. To overcome this issue, ExxonMobil recently developed a new concept, combining root arc welding and FSW. That is, a root arc weld is made prior to FSW that supports the normal loads associated with FSW. In the present work, mechanical properties of a FSW + root arc welded pipe steel are reported including microstructure and microhardness.

  3. Repair welding and online radiography

    International Nuclear Information System (INIS)

    The status of a joint project is reported, which is to develop a computerized testing and welding system for repair work in turbine blades. An X-ray radiographic testing device consisting of microfocus tube, manipulator and image processing system, is modified for this purpose so as to offer a greater number of image points scanned for image processing, and to thus achieve a better resolution for reliable detection of even very small defects. The consistency of the X-ray tube performance, which is a pre-requisite for automation, is to be achieved by a wa tercooled, high-duty tube head. The recording of defect coordinates in the repair zone is done for input into a welding robot to be developed by other partners in the project, so as to allow automated welding work. (orig.)

  4. The automatic NMR gaussmeter

    International Nuclear Information System (INIS)

    The paper describes the automatic gaussmeter operating according to the principle of nuclear magnetic resonance. There have been discussed the operating principle, the block diagram and operating parameters of the meter. It can be applied to measurements of induction in electromagnets of wide-line radio-spectrometers EPR and NMR and in calibration stands of magnetic induction values. Frequency range of an autodyne oscillator from 0,6 up to 86 MHz for protons is corresponding to the field range from 0.016 up to 2T. Applicaton of other nuclei, such as 7Li and 2D is also foreseen. The induction measurement is carried over automatically, and the NMR signal and value of measured induction are displayed on a monitor screen. (author)

  5. Automatic trend estimation

    CERN Document Server

    Vamos¸, C˘alin

    2013-01-01

    Our book introduces a method to evaluate the accuracy of trend estimation algorithms under conditions similar to those encountered in real time series processing. This method is based on Monte Carlo experiments with artificial time series numerically generated by an original algorithm. The second part of the book contains several automatic algorithms for trend estimation and time series partitioning. The source codes of the computer programs implementing these original automatic algorithms are given in the appendix and will be freely available on the web. The book contains clear statement of the conditions and the approximations under which the algorithms work, as well as the proper interpretation of their results. We illustrate the functioning of the analyzed algorithms by processing time series from astrophysics, finance, biophysics, and paleoclimatology. The numerical experiment method extensively used in our book is already in common use in computational and statistical physics.

  6. Residual stresses in zircaloy welds

    International Nuclear Information System (INIS)

    Welds in Zirconium-based alloys are susceptible to hydrogen embrittlement, as H enters the material due to dissociation of water. The yield strain for hydride cracking has a complex dependence on H concentration, stress state and texture. The large thermal gradients produced by the applied heat; drastically changes the texture of the material in the heat affected zone, enhancing the susceptibility to delayed hydride cracking. Normally hydrides tend to form as platelets that are parallel to the normal direction, but when welding plates, hydride platelets may form on cooling with their planes parallel to the weld and through the thickness of the plates. If, in addition to this there are significant tensile stresses, the susceptibility of the heat affected zone to delayed hydride cracking will be increased. Here we have measured the macroscopic and microscopic residual stressed that appear after PLASMA welding of two 6mm thick Zircaloy-4 plates. The measurements were based on neutron and synchrotron diffraction experiments performed at the Isis Facility, UK, and at Advanced Photon Source, USA, respectively. The experiments allowed assessing the effect of a post-weld heat treatment consisting of a steady increase in temperature from room temperature to 450oC over a period of 4.5 hours; followed by cooling with an equivalent cooling rate. Peak tensile stresses of (175± 10) MPa along the longitudinal direction were found in the as-welded specimen, which were moderately reduced to (150±10) MPa after the heat-treatment. The parent material showed intergranular stresses of (56±4) MPa, which disappeared on entering the heat-affected zone. In-situ experiments during themal cyclong of the material showed that these intergranular stresses result from the anisotropy of the thermal expansion coefficient of the hexagonal crystal lattice.

  7. Influence of shielding gas composition on weld profile in pulsed Nd:YAG laser welding of low carbon steel

    OpenAIRE

    Jokar, M.; F MalekGhaini; M J Torkamany; Sheikhi, M.

    2014-01-01

    Weld area and weld depth/width ratio can be considered to be of the most important geometrical factors in pulsed laser welding. The effects of carbon dioxide and oxygen additions to the argon shielding gas on the weld properties in pulsed laser welding of low carbon steel is investigated. Presence of carbon dioxide and oxygen up to 10 and 15 percent respectively decreases the weld geometrical factors. But, at higher levels of additions, the weld geometrical factors will increase. It is observ...

  8. Welding of plastic parts of electric pumps

    Energy Technology Data Exchange (ETDEWEB)

    Dreishner, E.P.; Belen' kii, M.Kh.

    1987-03-01

    The authors propose a new welding technique and machinery for the thermal contact welding thermoplastic parts of electric oil well pumps which efficiently creates welds of higher quality than those resulting from ultrasonic welding and also permits the use of cheaper and more readily available thermoplastics such as polyethylene and polypropylene which do not lend themselves to ultrasonic welding. The annual savings to the industry as a result of the implementation of their technique, and of the substitution of polypropylene for polyamide, amounts to 150,000 rubles.

  9. Advances in welding science - a perspective

    International Nuclear Information System (INIS)

    The ultimate goal of welding technology is to improve the joint integrity and increase productivity. Over the years, welding has been more of an art than a science, but in the last few decades major advances have taken place in welding science and technology. With the development of new methodologies at the crossroads of basic and applied sciences, enormous opportunities and potential exist to develop a science-based tailoring of composition, structure, and properties of welds with intelligent control and automation of the welding processes

  10. Automatic Wall Painting Robot

    OpenAIRE

    P.KEERTHANAA, K.JEEVITHA, V.NAVINA, G.INDIRA, S.JAYAMANI

    2013-01-01

    The Primary Aim Of The Project Is To Design, Develop And Implement Automatic Wall Painting Robot Which Helps To Achieve Low Cost Painting Equipment. Despite The Advances In Robotics And Its Wide Spreading Applications, Interior Wall Painting Has Shared Little In Research Activities. The Painting Chemicals Can Cause Hazards To The Human Painters Such As Eye And Respiratory System Problems. Also The Nature Of Painting Procedure That Requires Repeated Work And Hand Rising Makes It Boring, Time A...

  11. Automatic Program Reports

    OpenAIRE

    Lígia Maria da Silva Ribeiro; Gabriel de Sousa Torcato David

    2007-01-01

    To profit from the data collected by the SIGARRA academic IS, a systematic setof graphs and statistics has been added to it and are available on-line. Thisanalytic information can be automatically included in a flexible yearly report foreach program as well as in a synthesis report for the whole school. Somedifficulties in the interpretation of some graphs led to the definition of new keyindicators and the development of a data warehouse across the university whereeffective data consolidation...

  12. Automatic Inductive Programming Tutorial

    OpenAIRE

    Aler, Ricardo

    2006-01-01

    Computers that can program themselves is an old dream of Artificial Intelligence, but only nowadays there is some progress of remark. In relation to Machine Learning, a computer program is the most powerful structure that can be learned, pushing the final goal well beyond neural networks or decision trees. There are currently many separate areas, working independently, related to automatic programming, both deductive and inductive. The first goal of this tutorial is to give to the attendants ...

  13. Automatic food decisions

    DEFF Research Database (Denmark)

    Mueller Loose, Simone

    Consumers' food decisions are to a large extent shaped by automatic processes, which are either internally directed through learned habits and routines or externally influenced by context factors and visual information triggers. Innovative research methods such as eye tracking, choice experiments...... and food diaries allow us to better understand the impact of unconscious processes on consumers' food choices. Simone Mueller Loose will provide an overview of recent research insights into the effects of habit and context on consumers' food choices....

  14. Automatic Differentiation Variational Inference

    OpenAIRE

    Kucukelbir, Alp; Tran, Dustin; Ranganath, Rajesh; Gelman, Andrew; Blei, David M.

    2016-01-01

    Probabilistic modeling is iterative. A scientist posits a simple model, fits it to her data, refines it according to her analysis, and repeats. However, fitting complex models to large data is a bottleneck in this process. Deriving algorithms for new models can be both mathematically and computationally challenging, which makes it difficult to efficiently cycle through the steps. To this end, we develop automatic differentiation variational inference (ADVI). Using our method, the scientist on...

  15. Automaticity or active control

    DEFF Research Database (Denmark)

    Tudoran, Ana Alina; Olsen, Svein Ottar

    This study addresses the quasi-moderating role of habit strength in explaining action loyalty. A model of loyalty behaviour is proposed that extends the traditional satisfaction–intention–action loyalty network. Habit strength is conceptualised as a cognitive construct to refer to the psychologic......, respectively, between intended loyalty and action loyalty. At high levels of habit strength, consumers are more likely to free up cognitive resources and incline the balance from controlled to routine and automatic-like responses....

  16. Automatic digital image registration

    Science.gov (United States)

    Goshtasby, A.; Jain, A. K.; Enslin, W. R.

    1982-01-01

    This paper introduces a general procedure for automatic registration of two images which may have translational, rotational, and scaling differences. This procedure involves (1) segmentation of the images, (2) isolation of dominant objects from the images, (3) determination of corresponding objects in the two images, and (4) estimation of transformation parameters using the center of gravities of objects as control points. An example is given which uses this technique to register two images which have translational, rotational, and scaling differences.

  17. On the welded Tube map

    OpenAIRE

    Audoux, Benjamin

    2014-01-01

    This note investigates the so-called Tube map which connects welded knots, that is a quotient of the virtual knot theory, to ribbon torus-knots, that is a restricted notion of fillable knotted tori in the 4-sphere. It emphasizes the fact that ribbon torus-knots with a given filling are in one-to-one correspondence with welded knots before quotient under classical Reidemeister moves and reformulates these moves and the known sources of non-injectivity of the Tube map in terms of filling changes.

  18. Experimental Study of the Redistribution of Welding Distortion According to the Partial Removal of Welded Structure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Rae; Wang, Chao; Kim, Jae Woong [Yeungnam University, Kyungsan (Korea, Republic of)

    2015-07-15

    During the welding process, welding distortion is caused by the non-uniformity of the temperature distribution in the weldment. Welding distortion is redistributed because the residual stress and rigidity change according to the removal of the welded structure. In shipbuilding in particular, this phenomenon may be observed during the cutting process of lugs that are attached to blocks for transfer. The redistribution of welding distortion also causes problems, such as damage to the cutting tool. The aim of this study is to experimentally analyze the redistribution of welding distortion because of the partial removal of the welded structure. In the experiments conducted in this study, fillet welding and cutting were performed, and longitudinal bending and angular distortion in the welded structures were then investigated and analyzed.

  19. Weld pool flows during initial stages of keyhole formation in laser welding

    International Nuclear Information System (INIS)

    Weld pool transport phenomena during the transition from conduction-mode laser spot welding to keyhole laser spot welding of titanium were studied by numerical simulation. A range of laser powers were simulated and temperature dependent evaporation recoil pressure and cooling were applied as boundary conditions on the weld pool surface. Simulation results predicted a complex time-varying flow pattern during weld pool development. The surface-normal flow at the weld pool centre oscillated between upwards and downwards during the simulation time due to interaction of competing effects of evaporation recoil and surface tension pressures and laser heating and evaporation cooling. The results show that the laser weld pool flow dynamics play a key role during the transition from conduction-mode laser welding to keyhole welding.

  20. Real-time monitoring of weld penetration quality in roboticarc welding process

    Institute of Scientific and Technical Information of China (English)

    Wu Chuansong; Jia Chuanbao; Duan Xiaoning

    2008-01-01

    It is of great significance to develop an intelligent monitoring system for weld penetration defects such as incomplete penetration and burn-through in real-time during robotic arc welding process. In this paper, robotic gas metal arc welding experiments are carried out on the mild steel test pieces with Vee-type groove. Through-the-arc sensing method is used to capture the transient values of the welding voltage and current. The raw data of the captured welding current and voltage are processed statistically, and the feature vector S10 is extracted to correlate the welding conditions to the weld penetration information. It lays foundation for intelligent monitoring of weld quality in robotic arc welding.