WorldWideScience

Sample records for frequency induction welding

  1. HIGH FREQUENCY INDUCTION WELDING OF HIGH SILICON STEEL TUBES

    Directory of Open Access Journals (Sweden)

    Ricardo Miranda Alé

    2012-06-01

    Full Text Available High-Si steel is a low cost alternative for the fabrication of tubular structures resistant to atmospheric corrosion. However, the literature has often pointed out that steels presenting a higher Si content and/or a lower Mn/Si ratio have higher susceptibility to defects at the weld bond line during HFIW (High Frequency Induction Welding process, which has been widely used for manufacturing small diameter tubes. In this study the effect of the HFIW conditions on the quality of steel tubes with high-Si content and low Mn/Si ratio is investigated. The quality of welded tubes was determined by flare test and the defects in the bond line were identified by SEM. It has been found that higher welding speeds, V-convergence angles and power input should be applied in welding of high-Si steel, when compared to similar strength C-Mn steel.

  2. Development of high strength pipes grade API 5L X70 PSL2 offshore by the HFIW Process (High Frequency Induction Welding)

    Energy Technology Data Exchange (ETDEWEB)

    Cordeiro, Wilson R.; Melo, Luis C.R.; Gomes, Igor O.; Boni, Luiz P.; Sanctis, Marco A.M. di [Apolo Tubulars, Lorena, SP (Brazil)

    2009-07-01

    High strength pipes can be manufactured with excellency in dimensional tolerances, rapidity and efficiency through HFIW process (High Frequency Induction Welding). API 5L 6 5/8 x 0,374 in pipes were made of thin, hot rolled and coiled plates with dimensional 9,300 x 1.040,0 x 140.000 mm. Mechanical tests, chemical and microstructural analysis were performed. For the microstructural analysis, ferrite and perlitic structure were detected. All the results obtained are according to API 5L, 44{sup th} edition, 2008 for the grade API 5L X70 PSL2 Offshore. (author)

  3. Induction heat treatment of laser welds

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove; Sørensen, Joakim Ilsing

    2003-01-01

    In this paper, a new approach based on induction heat-treatment of flat laser welded sheets is presented. With this new concept, the ductility of high strength steels GA260 with a thickness of 1.8 mm and CMn with a thickness of 2.13 mm is believed to be improved by prolonging the cooling time from...... 750º to 450º C. Initially, a simple analytical model was used to calculate the ideal energy contributions from a CO2 high power laser source together with an induction heat source such that the temperature can be kept at 600º C for 2.5 seconds. This knowledge was then used for the design...... of an induction coil. A number of systematic laboratory tests were then performed in order to study the effects of the coil on bead-on-plate laser welded samples. In these tests, important parameters such as coil current and distance between coil and sample were varied. Temperature measurements were made...

  4. Modeling and experimental investigation of induction welding of thermoplastic composites and comparison with other welding processes

    NARCIS (Netherlands)

    Gouin O'Shaughnessey, P.; Dube, M; Fernandez Villegas, I.

    2016-01-01

    A three-dimensional finite element model of the induction welding of carbon fiber/polyphenylene sulfide thermoplastic composites is developed. The model takes into account a stainless steel mesh heating element located at the interface of the two composite adherends to be welded. This heating

  5. Laser/TIG Hybrid Welding of Pot for Induction Heater

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove; Sondrup, Lars de Caldas

    2004-01-01

    In this paper, systematic work is presented that shows the steps for realizing a hybrid welded tailored blank that is formed to a pot for induction heating. The bottom is made of ferritic stainless steel and the sides of austenitic stainless steel. Only the bottom will then interact directly with...... with the induction heater....

  6. An efficient method of spot welding Aluminium alloys with induction preheating

    Directory of Open Access Journals (Sweden)

    Jawad Saleem

    2016-12-01

    Full Text Available Steel has been the material of choice for automobile manufacturers. In the recent years material such as aluminium and its alloys are taking over the market because of their light weight. The use of aluminium, in automobile manufacturing can result in overall fuel efficiency. Spot welding aluminium alloys require higher electric power and less welding time as compared to steel. Welding guns that can produce an electric current which is approximately 2 to 3 times higher, as compared to steel are required for spot welding aluminium. An efficient method of spot welding Aluminium alloys with the preheating process has been proposed in this paper. Preheating Aluminium sheet before spot welding reduces the thermal and electrical resistance which brings down the electric current requirement to spot weld Aluminium structures. Both spot welding and induction preheating process have been modelled in this paper. The test results of the preheating process have also been verified with practical heating trials. The preheating is performed on-the-fly in advance to spot welding process. The results show that spot welding Al 6082 after preheating up to 200 oC, the output current requirements to make the spot weld are reduced by 22%.

  7. Influence of induction hardening parameters on the GS30Mn5 weld properties

    Directory of Open Access Journals (Sweden)

    V. Marušić

    2016-10-01

    Full Text Available This study examines parameters of post-weld heat treatment on the test specimens made of cast steel GS30Mn5. The welding is performed with shielded metal arc welding (SMAW process. The aim is to obtain the surface without illicit cracks, with hardness ranging from 320 up to 400 HB. After induction heating, the specimens are cooled alternately with air and water. Decreased speed of quenching results in avoiding the occurrence of illicit splashes, while the hardness is maintained within the prescribed limits.

  8. Calculation of Leakage Inductance for High Frequency Transformers

    DEFF Research Database (Denmark)

    Ouyang, Ziwei; Jun, Zhang; Hurley, William Gerard

    2015-01-01

    Frequency dependent leakage inductance is often observed. High frequency eddy current effects cause a reduction in leakage inductance. The proximity effect between adjacent layers is responsible for the reduction of leakage inductance. This paper gives a detailed analysis of high frequency leakag...

  9. Conductive films of silver nanoparticles as novel susceptors for induction welding of thermoplastic composites

    Science.gov (United States)

    Dermanaki Farahani, Rouhollah; Janier, Mathieu; Dubé, Martine

    2018-03-01

    In the present work, a conductive film of silver nanoparticles (nAg) as a novel heating element type, called susceptor, was developed and tested for induction welding of carbon fiber/polyphenylene sulfide (CF/PPS) thermoplastic composites, i.e., unidirectional pre-impregnated 16 plies of CF/PPS compression-molded in a quasi-isotropic stacking sequence. The nAg were synthesized, dispersed in deionized (DI) water and casted onto a pure PPS film, resulting in a conductive film upon the evaporation of DI water and thermal post-annealing. The thermal annealing at 250 °C significantly (by 7 orders) decreased the film’s electrical resistivity from 9.4 × 103 down to 3.1 × 10‑4 Ω cm. The new susceptors led to fast heating rates in induction welding when compared to the standard stainless steel mesh susceptors under similar welding conditions. Lap shear mechanical testing revealed that the apparent lap shear strength (LSS) is sensitive to the susceptors’ resistivity and the input current. A relatively high LSS value was achieved for the specimens welded using the new susceptors which exceeded the value of those welded using stainless steel mesh susceptors (28.3 MPa compared to 20 MPa). The weld interface and specimens’ cross-section observation revealed that the nAg were dispersed and embedded into the resin upon welding. This study contains preliminary results that show high potential of nanoparticles as effective susceptors to further improve the mechanical performance of the joints in welding of thermoplastic composites.

  10. Proton-irradiation technology for high-frequency high-current silicon welding diode manufacturing

    Science.gov (United States)

    Lagov, P. B.; Drenin, A. S.; Zinoviev, M. A.

    2017-05-01

    Different proton irradiation regimes were tested to provide more than 20 kHz-frequency, soft reverse recovery “snap-less” behavior, low forward voltage drop and leakage current for 50 mm diameter 7 kA/400 V welding diode Al/Si/Mo structure. Silicon diode with such parameters is very suitable for high frequency resistance welding machines of new generation for robotic welding.

  11. Welding.

    Science.gov (United States)

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This curriculum guide is designed for use by South Carolina vocational education teachers as a continuing set of lesson plans for a two-year course on welding. Covered in the individual sections of the guide are the following topics: an orientation to welding, oxyacetylene welding, advanced oxyacetylene welding, shielded metal arc welding, TIG…

  12. The high frequency characteristics of laser reflection and visible light during solid state disk laser welding

    International Nuclear Information System (INIS)

    Gao, Xiangdong; You, Deyong; Katayama, Seiji

    2015-01-01

    Optical properties are related to weld quality during laser welding. Visible light radiation generated from optical-induced plasma and laser reflection is considered a key element reflecting weld quality. An in-depth analysis of the high-frequency component of optical signals is conducted. A combination of a photoelectric sensor and an optical filter helped to obtain visible light reflection and laser reflection in the welding process. Two groups of optical signals were sampled at a high sampling rate (250 kHz) using an oscilloscope. Frequencies in the ranges 1–10 kHz and 10–125 kHz were investigated respectively. Experimental results showed that there was an obvious correlation between the high-frequency signal and the laser power, while the high-frequency signal was not sensitive to changes in welding speed. In particular, when the defocus position was changed, only a high frequency of the visible light signal was observed, while the high frequency of the laser reflection signal remained unchanged. The basic correlation between optical features and welding status during the laser welding process is specified, which helps to provide a new research focus for investigating the stability of welding status. (letter)

  13. Frequency characteristics of geomagnetic induction anomalies in ...

    Indian Academy of Sciences (India)

    P V Vijaya Kumar

    2017-10-07

    Oct 7, 2017 ... (BAG) consists of 8 km thick sediments and named as Ulva basin (UB). The thickness of the sediments in south and SW are less due to extensive volcanic .... period range of 8–128 min using robust regression technique (Egbert and Booker 1993). The mag- nitude (S) and azimuth (φ) of these induction.

  14. Quantum inductance and negative electrochemical capacitance at finite frequency

    OpenAIRE

    Wang, J.; Wang, B. G.; Guo, H.

    2007-01-01

    We report on theoretical investigations of frequency dependent quantum capacitance. It is found that at finite frequency a quantum capacitor can be characterized by a classical RLC circuit with three parameters: a static electrochemical capacitance, a charge relaxation resistance, and a quantum inductance. The quantum inductance is proportional to the characteristic time scale of electron dynamics and due to its existence, the time dependent current can accumulate a phase delay and becomes la...

  15. Characterization the microstructure of pulsed Nd:YAG welding method in low frequencies; correlation with tensile and fracture behavior in laser-welded nitinol joints

    Science.gov (United States)

    Shojaei Zoeram, Ali; Rahmani, Aida; Asghar Akbari Mousavi, Seyed Ali

    2017-05-01

    The precise controllability of heat input in pulsed Nd:YAG welding method provided by two additional parameters, frequency and pulse duration, has made this method very promising for welding of alloys sensitive to heat input. The poor weldability of Ti-rich nitinol as a result of the formation of Ti2Ni IMC has deprived us of the unique properties of this alloy. In this study, to intensify solidification rate during welding of Ti-rich nitinol, pulsed Nd:YAG laser beam in low frequency was employed in addition to the employment of a copper substrate. Specific microstructure produced in this condition was characterized and the effects of this microstructure on tensile and fracture behavior of samples welded by two different procedures, full penetration and double-sided method with halved penetration depth for each side were investigated. The investigations revealed although the combination of low frequencies, the use of a high thermal conductor substrate and double-sided method eliminated intergranular fracture and increased tensile strength, the particular microstructure, built in the pulsed welding method in low frequencies, results to the formation of the longitudinal cracks during the first stages of tensile test at weld centerline. This degrades tensile strength of welded samples compared to base metal. The results showed samples welded in double-sided method performed much better than samples welded in full penetration mode.

  16. Residual stress improvement for pipe weld by means of induction heating pre-flawed pipe

    International Nuclear Information System (INIS)

    Umemoto, T.; Yoshida, K.; Okamoto, A.

    1980-01-01

    The intergranular stress corrosion cracking (IGSCC) has been found in type 304 stainless steel piping of several BWR plants. It is already well known that IGSCC is most likely to occur when three essential factors, material sensitization, high tensile stress and corrosive environment, are present. If the welding residual stress is sufficiently high (200 to approximately 400 MPa) in the inside piping surface near the welded joint, then it may be one of the biggest contributors to IGSCC. If the residual stress is reduced or reversed by some way, the IGSCC will be effectively mitigated. In this paper a method to improve the residual stress named IHSI (Induction Heating Stress Improvement) is explained. IHSI aims to improve the condition of residual stress in the inside pipe surface using the thermal stress induced by the temperature difference in pipe wall, that is produced when the pipe is heated from the outside surface by an induction heating coil and cooled on the inside surface by water simultaneously. This method becomes more attractive when it can be successfully applied to in-service piping which might have some pre-flaw. In order to verify the validity of IHSI for such piping, some experiments and calculations using finite element method were conducted. These results are mainly discussed in this paper from the view-points of residual stress, flaw behaviour during IHSI and material deterioration. (author)

  17. Effect of stainless steel manual metal arc welding fume on free radical production, DNA damage, and apoptosis induction.

    Science.gov (United States)

    Antonini, James M; Leonard, Stephen S; Roberts, Jenny R; Solano-Lopez, Claudia; Young, Shih-Houng; Shi, Xianglin; Taylor, Michael D

    2005-11-01

    Questions exist concerning the potential carcinogenic effects after welding fume exposure. Welding processes that use stainless steel (SS) materials can produce fumes that may contain metals (e.g., Cr, Ni) known to be carcinogenic to humans. The objective was to determine the effect of in vitro and in vivo welding fume treatment on free radical generation, DNA damage, cytotoxicity and apoptosis induction, all factors possibly involved with the pathogenesis of lung cancer. SS welding fume was collected during manual metal arc welding (MMA). Elemental analysis indicated that the MMA-SS sample was highly soluble in water, and a majority (87%) of the soluble metal was Cr. Using electron spin resonance (ESR), the SS welding fume had the ability to produce the biologically reactive hydroxyl radical (*OH), likely as a result of the reduction of Cr(VI) to Cr(V). In vitro treatment with the MMA-SS sample caused a concentration-dependent increase in DNA damage and lung macrophage death. In addition, a time-dependent increase in the number of apoptotic cells in lung tissue was observed after in vivo treatment with the welding fume. In summary, a soluble MMA-SS welding fume was found to generate reactive oxygen species and cause DNA damage, lung macrophage cytotoxicity and in vivo lung cell apoptosis. These responses have been shown to be involved in various toxicological and carcinogenic processes. The effects observed appear to be related to the soluble component of the MMA-SS sample that is predominately Cr. A more comprehensive in vivo animal study is ongoing in the laboratory that is continuing these experiments to try to elucidate the potential mechanisms that may be involved with welding fume-induced lung disease.

  18. High frequency induction of somatic embryos and plantlet ...

    African Journals Online (AJOL)

    High frequency induction of somatic embryos and plantlet regeneration from nodal explants of Hygrophila spinosa T. Anders. A Varshney, A Shahzad, M Anis. Abstract. An efficient protocol is described for the rapid in vitro plant regeneration of a medicinally important plant, Hygrophila spinosa through direct somatic ...

  19. Feedback control of laser welding based on frequency analysis of light emissions and adaptive beam shaping

    Czech Academy of Sciences Publication Activity Database

    Mrňa, Libor; Šarbort, Martin; Řeřucha, Šimon; Jedlička, Petr

    2012-01-01

    Roč. 39, NOV (2012), s. 784-791 ISSN 1875-3892. [LANE 2012. Laser Assisted Net Shape Engineering /7./ International Conference on Photonic Technologies. Fürth, 12.11.2012-15.12.2012] Institutional support: RVO:68081731 Keywords : laser weld ing * feedback control * frequency analysis * adaptive beam shaping Subject RIV: BH - Optics, Masers, Lasers

  20. 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…

  1. Flaw-size measurement in a weld samples by ultrasonic frequency analysis

    International Nuclear Information System (INIS)

    Adler, L.; Cook, K.V.; Whaley, H.L. Jr.; McClung, R.W.

    1975-01-01

    An ultrasonic frequency-analysis technique was developed and applies to characterize flaws in an 8-in. (203-mm) thick heavy-section steel weld specimen. The technique applies a multitransducer system. The spectrum of the received broad-band signal is frequency analyzed at two different receivers for each of the flaws. From the two spectra, the size and orientation of the flaw are determined by the use of an analytic model proposed earlier. (auth)

  2. Energy saving work of frequency controlled induction cage machine

    International Nuclear Information System (INIS)

    Gnacinski, P.

    2007-01-01

    Energy saving work, understood as lowering the supply voltage when load torque is much less than rated, is one way of reducing power losses in an induction cage machine working with a variable load. Reduction in power losses also affects the thermal properties of an induction machine because the energy saving work allows the temperature rise of the windings to decrease. Thanks to a lower temperature of the windings, the same load torque can be carried by a machine of less rated power. The ability of energy saving work to reduce the temperature of windings depends on the thermal properties of an induction machine, which are different in the case of a machine with foreign ventilation and its own ventilation. This paper deals with the thermal effect of energy saving work on a frequency controlled induction cage machine. A comparison of the properties of a machine with its own and outside ventilation is presented. The results of the investigations are shown for a 3 kW induction cage machine with the two previously mentioned ways of ventilation: one provided with a fan placed on a shaft and the other provided with a fan driven by an auxiliary motor

  3. Frequency Analysis of Acoustic Emission - Application to machining and welding

    Science.gov (United States)

    Snoussi, A.

    1987-01-01

    Ultrasonic acoustic waves were seized and exploited within a bandwidth ranging from 30 kHz to 55 kHz for non-destructive control when boring three kinds of steel with a digitally programmed drill. In addition, these waves were considered in soldering two steels and one aluminum using T.I.G. process. Spectrum analysis of acoustic emissions produced during the drill is closely related to the extraction of turnings from the metal. Because of the wick's progressive wearing out, the spectrum tends to be close to the machine's own noise spectrum. Meanwhile in the soldering operation of test-tubes of 2 mm thickness, the frequency analysis shows a particular frequency called signature corresponding to the flow of protection gas. Other frequencies associated to some internal defects in the soldering process as a delay in the fissure and a lack in the fusion were detected.

  4. Measurement of flaw size in a weld sample by ultrasonic frequency analysis

    International Nuclear Information System (INIS)

    Whaley, H.L. Jr.; Adler, L.; Cook, K.V.; McClung, R.W.

    1975-05-01

    An ultrasonic frequency analysis technique has been developed and applied to the measurement of flaws in an 8-in.-thick heavy-section steel specimen belonging to the Pressure Vessel Research Committee program. Using the technique the flaws occurring in the weld area were characterized in quantitative terms of both dimension and orientation. Several modifications of the technique were made during the study to include the application of several transducers and to consider ultrasonic mode conversion. (U.S.)

  5. Special Features of Induction Annealing of Friction Stir Welded Joints of Medium-Alloy Steels

    Science.gov (United States)

    Priymak, E. Yu.; Stepanchukova, A. V.; Bashirova, E. V.; Fot, A. P.; Firsova, N. V.

    2018-01-01

    Welded joints of medium-alloy steels XJY750 and 40KhN2MA are studied in the initial condition and after different variants of annealing. Special features of the phase transformations occurring in the welded steels are determined. Optimum modes of annealing are recommended for the studied welded joints of drill pipes, which provide a high level of mechanical properties including the case of impact loading.

  6. A Variable Frequency, Mis-Match Tolerant, Inductive Plasma Source

    Science.gov (United States)

    Rogers, Anthony; Kirchner, Don; Skiff, Fred

    2014-10-01

    Presented here is a survey and analysis of an inductively coupled, magnetically confined, singly ionized Argon plasma generated by a square-wave, variable frequency plasma source. The helicon-style antenna is driven directly by the class ``D'' amplifier without matching network for increased efficiency while maintaining independent control of frequency and applied power at the feed point. The survey is compared to similar data taken using a traditional exciter--power amplifier--matching network source. Specifically, the flexibility of this plasma source in terms of the independent control of electron plasma temperature and density is discussed in comparison to traditional source arrangements. Supported by US DOE Grant DE-FG02-99ER54543.

  7. High frequency electromagnetic processes in induction motors supplied from PWM inverters

    Directory of Open Access Journals (Sweden)

    Ioan Ţilea

    2010-12-01

    Full Text Available The paper presents the electromagnetic interference between induction motors and inverters when at high frequency electromagnetic process appears in induction motors having a parallel resonant effect because of parasitic capacitive coupling between windings and ground, using a numerical model in simulink and a high frequency induction motor equivalent circuit model this effect is shown.

  8. Effect of inter-tissue inductive coupling on multi-frequency imaging of intracranial hemorrhage by magnetic induction tomography

    Science.gov (United States)

    Xiao, Zhili; Tan, Chao; Dong, Feng

    2017-08-01

    Magnetic induction tomography (MIT) is a promising technique for continuous monitoring of intracranial hemorrhage due to its contactless nature, low cost and capacity to penetrate the high-resistivity skull. The inter-tissue inductive coupling increases with frequency, which may lead to errors in multi-frequency imaging at high frequency. The effect of inter-tissue inductive coupling was investigated to improve the multi-frequency imaging of hemorrhage. An analytical model of inter-tissue inductive coupling based on the equivalent circuit was established. A set of new multi-frequency decomposition equations separating the phase shift of hemorrhage from other brain tissues was derived by employing the coupling information to improve the multi-frequency imaging of intracranial hemorrhage. The decomposition error and imaging error are both decreased after considering the inter-tissue inductive coupling information. The study reveals that the introduction of inter-tissue inductive coupling can reduce the errors of multi-frequency imaging, promoting the development of intracranial hemorrhage monitoring by multi-frequency MIT.

  9. Estimation and control of droplet size and frequency in projected spray mode of a gas metal arc welding (GMAW) process.

    Science.gov (United States)

    Anzehaee, Mohammad Mousavi; Haeri, Mohammad

    2011-07-01

    New estimators are designed based on the modified force balance model to estimate the detaching droplet size, detached droplet size, and mean value of droplet detachment frequency in a gas metal arc welding process. The proper droplet size for the process to be in the projected spray transfer mode is determined based on the modified force balance model and the designed estimators. Finally, the droplet size and the melting rate are controlled using two proportional-integral (PI) controllers to achieve high weld quality by retaining the transfer mode and generating appropriate signals as inputs of the weld geometry control loop. Copyright © 2011 ISA. Published by Elsevier Ltd. All rights reserved.

  10. Research of the multipolar induction traction frequency regulated motor

    Directory of Open Access Journals (Sweden)

    V. Ia. Bespalov

    2014-01-01

    Full Text Available The paper considers the application features of traction induction electric motors in transmissions of vehicles. It shows that one of important stages in their designing is to choose the number of poles. In traction electric drives engines with the raised number of poles without comprehensive assessment of such solution are often applied. The paper investigates dynamic and power characteristics of the multi-polar traction asynchronous engine (TAE designed and made for using in the individual electric drive of heavy-load wheeled cars. The basic functional elements of the model to simulate the electric drive in Matlab environment with the Simulink and SimPower Systems applications in the structure with vector control are described, and the simulation modeling results of its dynamic mechanical characteristics are provided. It is established that because of increased alternating frequency of currents of the multi-polar engine in the range of high speeds there is an excessive decrease in the torque and the requirement for constancy of the target capacity, corresponding to the specified traction characteristic is not fulfilled. It is a consequence of the waveform distortion of engine phase current in the range of high speeds because of incapability of the power source to compensate an increasing EMF of movement as the speed continues to grow.The paper studies the influence of increased current frequencies on the additional losses in the engine. The analysis of electromagnetic field penetration depth in the copper conductor of stator winding at high frequency allowed us to establish a significant skin – effect. The quantitative assessment is given to this phenomenon by results of numerical calculation of electromagnetic field distribution in a stator groove. Significant increase in additional losses in the engine is established, and estimates of flow loss extent because of damping actions of eddy currents in the laminated steel of stator at

  11. MODELLING AND SIMULATION OF HIGH FREQUENCY INVERTER FOR INDUCTION HEATING APPLICATION

    OpenAIRE

    SACHIN S. BANKAR; Dr. PRASAD M. JOSHI

    2016-01-01

    This paper presents modelling and simulation of high frequency inverter for induction heating applications. Induction heating has advantages like higher efficiency, controlled heating, safety and pollution free therefore this technology is used in industrial, domestic and medical applications. The high frequency full bridge inverter is used for induction heating, also MOSFET is used as a switching device for inverter and the control strategy used for inverter is Bipolar PWM control. The size ...

  12. Thermoplastic welding apparatus and method

    Energy Technology Data Exchange (ETDEWEB)

    Matsen, Marc R.; Negley, Mark A.; Geren, William Preston; Miller, Robert James

    2017-03-07

    A thermoplastic welding apparatus includes a thermoplastic welding tool, at least one tooling surface in the thermoplastic welding tool, a magnetic induction coil in the thermoplastic welding tool and generally encircling the at least one tooling surface and at least one smart susceptor in the thermoplastic welding tool at the at least one tooling surface. The magnetic induction coil is adapted to generate a magnetic flux field oriented generally parallel to a plane of the at least one smart susceptor.

  13. Research of the multipolar induction traction frequency regulated motor

    OpenAIRE

    V. Ia. Bespalov; A. B. Krasovskii; M. V. Panihin; V. G. Fisenko

    2014-01-01

    The paper considers the application features of traction induction electric motors in transmissions of vehicles. It shows that one of important stages in their designing is to choose the number of poles. In traction electric drives engines with the raised number of poles without comprehensive assessment of such solution are often applied. The paper investigates dynamic and power characteristics of the multi-polar traction asynchronous engine (TAE) designed and made for using in the individual...

  14. Quantum inductance and high frequency oscillators in graphene nanoribbons

    Science.gov (United States)

    Begliarbekov, Milan; Strauf, Stefan; Search, Christopher P.

    2011-04-01

    Here we investigate high frequency AC transport through narrow graphene nanoribbons with top-gate potentials that form a localized quantum dot. We show that as a consequence of the finite dwell time of an electron inside the quantum dot (QD), the QD behaves like a classical inductor at sufficiently high frequencies \\omega \\gtrsim 50 GHz. When the geometric capacitance of the top-gate and the quantum capacitance of the nanoribbon are accounted for, the admittance of the device behaves like a classical serial RLC circuit with resonant frequencies ω ~ 100-900 GHz and Q-factors greater than 106. These results indicate that graphene nanoribbons can serve as all-electronic ultra-high frequency oscillators and filters, thereby extending the reach of high frequency electronics into new domains.

  15. Model of inductive plasma production assisted by radio-frequency wave in tokamaks

    International Nuclear Information System (INIS)

    Hasegawa, Makoto; Hanada, Kazuaki; Sato, Kohnosuke

    2007-01-01

    For initial plasma production, an induction electric field generated by applying voltage to a poloidal field (PF) coil system is used to produce a Townsend avalanche breakdown. When the avalanche margins are small, as for the International Thermonuclear Experimental Reactor (ITER) in which the induction electric field is about 0.3 V/m, the assistance of radio-frequency waves (RF) is provided to reduce the induction electric field required for reliable breakdown. However, the conditions of RF-assisted breakdown are not clear. Here, the effects of both RF and induction electric field on the RF-assisted breakdown are evaluated considering the electron loss. When traveling loss is the dominant loss, a simple model of an extended Townsend avalanche is proposed. In this model, the induction electric field required for RF-assisted breakdown can be decreased to half that required for induction breakdown. (author)

  16. Induction heating of gears - pulsing dual-frequency concept

    Directory of Open Access Journals (Sweden)

    R. Przyłucki

    2013-04-01

    Full Text Available The paper concerns analysis of gears hardening process. In order to obtain required temperature distribution several variations of single and combined frequencies for selected gear-wheel configurations were considered. The paper includes the calculation models and analysis of geometry and current intensity as well frequency influence on temperature distribution of the tooth surface. All calculations have been carried out by means of the use of Flux3D simulation program, which enables to provide, coupled electromagnetic and temperature fields analysis.

  17. Variable-frequency inverter controls torque, speed, and braking in ac induction motors

    Science.gov (United States)

    Nola, F. J.

    1974-01-01

    Dc to ac inverter provides optimum frequency and voltage to ac induction motor, in response to different motor-load and speed requirements. Inverter varies slip frequency of motor in proportion to required torque. Inverter protects motor from high current surges, controls negative slip to apply braking, and returns energy stored in momentum of load to dc power source.

  18. The Control of Voltage and Frequency of Self-excited Three-Phase Induction Generator

    Directory of Open Access Journals (Sweden)

    Ionel Dragomirescu

    2011-10-01

    Full Text Available In this work it is presented the control of voltage and frequency of threephase induction generator in autonomous regime. It is adjusted the intensity of voltage and frequency at the terminals of the consumer by means of frequency converter, in conditions of driving the induction generator at constant speed. System testing and measurements were carried out by the Laboratory for Designing and Testing of Equipment Excitation and Automation of the Center for Research in Hydraulics, Automation and Thermal Processes (CCHAPT within “Eftimie Murgu” University of Resita.

  19. Influence of the parameters of a high-frequency acoustic wave on the structure, properties, and plastic flow of metal in the zone of a joint of materials welded by ultrasound-assisted explosive welding

    Science.gov (United States)

    Peev, A. P.; Kuz'min, S. V.; Lysak, V. I.; Kuz'min, E. V.; Dorodnikov, A. N.

    2017-05-01

    The results of an investigation of the influence of the parameters of high-frequency acoustic wave on the structure and properties of the zone of joint of homogeneous metals bonded by explosive welding under the action of ultrasound have been presented. The influence of the frequency and amplitude of ultrasonic vibrations on the structure and properties of the explosively welded joints compared with the samples welded without the application of ultrasound has been established. The action of high-frequency acoustic waves on the metal leads to a reduction in the dynamic yield stress, which changes the properties of the surface layers of the metal and the conditions of the formation of the joint of the colliding plates upon the explosive welding. It has been shown that the changes in the length and amplitude of waves that arise in the weld joint upon the explosive welding with the simultaneous action of ultrasonic vibrations are connected with a decrease in the magnitude of the deforming pulse and time of action of the compressive stresses that exceed the dynamic yield stress beyond the point of contact.

  20. High-Precision Hysteresis Sensing of the Quartz Crystal Inductance-to-Frequency Converter.

    Science.gov (United States)

    Matko, Vojko; Milanović, Miro

    2016-06-28

    A new method for the automated measurement of the hysteresis of the temperature-compensated inductance-to-frequency converter with a single quartz crystal is proposed. The new idea behind this method is a converter with two programmable analog switches enabling the automated measurement of the converter hysteresis, as well as the temperature compensation of the quartz crystal and any other circuit element. Also used is the programmable timing control device that allows the selection of different oscillating frequencies. In the proposed programmable method two different inductances connected in series to the quartz crystal are switched in a short time sequence, compensating the crystal's natural temperature characteristics (in the temperature range between 0 and 50 °C). The procedure allows for the measurement of the converter hysteresis at various values of capacitance connected in parallel with the quartz crystal for the converter sensitivity setting at selected inductance. It, furthermore, enables the measurement of hysteresis at various values of inductance at selected parallel capacitance (sensitivity) connected to the quartz crystal. The article shows that the proposed hysteresis measurement of the converter, which converts the inductance in the range between 95 and 100 μH to a frequency in the range between 1 and 200 kHz, has only 7 × 10(-13) frequency instability (during the temperature change between 0 and 50 °C) with a maximum 1 × 10(-11) hysteresis frequency difference.

  1. High-Precision Hysteresis Sensing of the Quartz Crystal Inductance-to-Frequency Converter

    Directory of Open Access Journals (Sweden)

    Vojko Matko

    2016-06-01

    Full Text Available A new method for the automated measurement of the hysteresis of the temperature-compensated inductance-to-frequency converter with a single quartz crystal is proposed. The new idea behind this method is a converter with two programmable analog switches enabling the automated measurement of the converter hysteresis, as well as the temperature compensation of the quartz crystal and any other circuit element. Also used is the programmable timing control device that allows the selection of different oscillating frequencies. In the proposed programmable method two different inductances connected in series to the quartz crystal are switched in a short time sequence, compensating the crystal’s natural temperature characteristics (in the temperature range between 0 and 50 °C. The procedure allows for the measurement of the converter hysteresis at various values of capacitance connected in parallel with the quartz crystal for the converter sensitivity setting at selected inductance. It, furthermore, enables the measurement of hysteresis at various values of inductance at selected parallel capacitance (sensitivity connected to the quartz crystal. The article shows that the proposed hysteresis measurement of the converter, which converts the inductance in the range between 95 and 100 μH to a frequency in the range between 1 and 200 kHz, has only 7 × 10−13 frequency instability (during the temperature change between 0 and 50 °C with a maximum 1 × 10−11 hysteresis frequency difference.

  2. Laser welding engineering

    International Nuclear Information System (INIS)

    Bhieh, N. M.; El Eesawi, M. E.; Hashkel, A. E.

    2007-01-01

    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

  3. Preventing Inductive Output Impedance of High-Frequency Emitter Follower Stages

    Directory of Open Access Journals (Sweden)

    R. C. Tozer

    1997-04-01

    Full Text Available Large output inductance is one of major issues of high-frequency emitter follower design. The most often suggested technique to reduce its value is the decreasing of AC transconductance which offers small output inductance at the expense of loosing low output resistance. The paper presents a different approach; it is shown that output inductance can be completely cancelled while keeping very low output resistance by introducing a pole at the input node which may be more suitable in many types of design. Complete analytical evaluation based on the full hybrid-n model of the bipolar transistor device is given.

  4. Arc and resistance welding and tumours of the endocrine glands: a Swedish case-control study with focus on extremely low frequency magnetic fields.

    Science.gov (United States)

    Håkansson, N; Stenlund, C; Gustavsson, P; Johansen, C; Floderus, B

    2005-05-01

    Mechanisms for potential effects of extremely low frequency (ELF) magnetic fields on carcinogenesis have not been identified. A potential pathway could be an interaction with the endocrine system. To analyse occupational exposure to ELF magnetic fields from welding, and tumours of the endocrine glands. This case-control study was based on a cohort with an increased prevalence of high exposed individuals. A total of 174 incident cases of tumours of the endocrine glands, 1985-94, were identified and data were obtained from 140 (80%) of these cases; 1692 controls frequency matched on sex and age were selected, and information on 1306 (77%) individuals was obtained. A short questionnaire was sent to a work administrator at the workplaces of the cases and controls. The exposure assessment was based on questions about job tasks, exposure to different types of welding, and exposure to solvents. There was an overall increased risk for all tumours of the endocrine glands for individuals who had been welding sometime during the follow up. The increased risk was attributable to arc welding; for resistance welding there was no clear evidence of an association. We found an increased risk for the adrenal glands in relation to arc welding, and for the parathyroid glands in relation to both arc welding and resistance welding. An imprecise increase in risk was also noted for tumours of the pituitary gland for arc welding. No confounding effect was found for solvent exposure, and there was no sign of biological interaction. The increased risks of endocrine gland tumours related to welding might be explained by exposure to high levels of ELF magnetic fields.

  5. A Novel Soft Switching PWM Power Frequency Converter with Non DC Smoothing Filter Link for Consumer High Frequency Induction Heating

    Science.gov (United States)

    Sugimura, Hisayuki; Muraoka, Hidekazu; Hiraki, Eiji; Hirota, Izuo; Yasui, Kenji; Omori, Hideki; Lee, Hyun-Woo; Nakaoka, Mutsuo

    In this paper, high frequency power converter without DC smoothing electrolytic capacitor filter link which convert the 100V/200Vrms and 60Hz single phase utility frequency AC power into a high frequency AC. This proposed high frequency AC power converter without electrolytic capacitor filter can operate under a principle of soft switching PWM based on a lossless capacitor snubber is proposed and demonstrated for consumer high frequency induction heating (IH). In particular, this high frequency power converter capable of producing a high frequency AC more than 20kHz is developed for consumer IH applications as hot water producer and steamer based on the specially designed spiral type IH-Dual Packs Heater (DPH), which includes the dual mode pulse modulation control scheme based on soft switching PWM for high output power setting and commercial frequency AC zero voltage soft switching pulse density modulation (PDM) for low output power settings. This developed high frequency power frequency converter using trench gate IGBTs is clarified on the basis of experimental and simulation results for its circuit operation of the utility frequency AC to high frequency AC frequency PWM power converter without the electrolytic capacitor bank DC filter link for the IH hot water and IH steamer. These IH appliances are based upon an innovative electromagnetic IH-DPH for fluid heating as heat exchanger in consumer pipeline. Finally, its power regulation characteristics, power conversion efficiency and harmonic current components characteristics including power factor in utility AC grid side are evaluated and discussed from an experimental point of view. The practical effectiveness of this utility frequency AC to high frequency AC soft switching high power frequency converter defined conveniently as high frequency soft switching cyclo-inverter is proved as one of the important products effective for next generation IH application all electricity power utilizations.

  6. [The dental soldering by means of high frequency induction heating (author's transl)].

    Science.gov (United States)

    Ichimaru, T; Kameda, T

    1977-04-01

    The authors examined the methods of high frequency induction soldering, especially Loop-method, other than the gas flame soldering which was known generally. The details which was done are: (1) about the form of induction coil, and the relative places of the coil and restrative appliance, and some supplementary appliances of them. (2) about strength of soldered joints of Co-Cr wire using silver solder and Pd-solder, and observation on the corrosion of soldered-joints by the scanning electron-microscope. (3) about the comparison of the characteristics of Co-Cr wire by means of high-frequency induction heating and gas-flame one. (4) about the examples of soldering of porcelain crown-bridge and clasp wire attached on the dental cast, and possibility of soldering techniques of them on the dental cast. The authors found that the high frequency induction method was preeminent from the other method on the point of (a) the characteristic of heated wire, (b) the strength of soldered joints, (c) the easiness of operating of them, and (d) the possibility of soldering using the high-melting point of Pd-solder, and the soldering of them on the dental cast. Therefore we can enough respect the application on the dental area of this apparatus and this techniques of the high-frequency induction soldering.

  7. Method and apparatus for monitoring the rotating frequency of de-energized induction motors

    Science.gov (United States)

    Mikesell, Harvey E.; Lucy, Eric

    1998-01-01

    The rotational speed of a coasting induction motor is measured by sensing e residual electrical voltages at the power terminals of the motor, thus eliminating the need for conventional tachometer equipment, additional mechanical components or modifications to the induction motor itself. The power terminal voltage signal is detected and transformed into a DC voltage proportional to the frequency of the signal. This DC voltage can be input to the control system of a variable frequency motor controller to regulate the output characteristics thereof relative to the speed of the coasting motor.

  8. Voltage and frequency control of wind-powered islanded microgrids based on induction generator and STATCOM

    DEFF Research Database (Denmark)

    Bouzid, Allal; Sicard, Pierre; Guerrero, Josep M.

    2015-01-01

    This paper presents a comprehensive modeling of a three-phase cage induction machine used as a self-excited squirrel-cage induction generator (SEIG), and discusses the regulation of the voltage and frequency of a self-excited SEIG based on the action of the static synchronous Compensator (STATCOM......). The STATCOM with the proposed controller consists of a three-phase voltage-sourced inverter and a DC voltage. The compensator can provide the active and reactive powers and regulate AC system bus voltage and the frequency, but also may enhance the load stability. Moreover, a feed forward control method...

  9. Variable frequency inverter for ac induction motors with torque, speed and braking control

    Science.gov (United States)

    Nola, F. J. (Inventor)

    1975-01-01

    A variable frequency inverter was designed for driving an ac induction motor which varies the frequency and voltage to the motor windings in response to varying torque requirements for the motor so that the applied voltage amplitude and frequency are of optimal value for any motor load and speed requirement. The slip frequency of the motor is caused to vary proportionally to the torque and feedback is provided so that the most efficient operating voltage is applied to the motor. Winding current surge is limited and a controlled negative slip causes motor braking and return of load energy to a dc power source.

  10. High resolution switching mode inductance-to-frequency converter with temperature compensation.

    Science.gov (United States)

    Matko, Vojko; Milanović, Miro

    2014-10-16

    This article proposes a novel method for the temperature-compensated inductance-to-frequency converter with a single quartz crystal oscillating in the switching oscillating circuit to achieve better temperature stability of the converter. The novelty of this method lies in the switching-mode converter, the use of additionally connected impedances in parallel to the shunt capacitances of the quartz crystal, and two inductances in series to the quartz crystal. This brings a considerable reduction of the temperature influence of AT-cut crystal frequency change in the temperature range between 10 and 40 °C. The oscillator switching method and the switching impedances connected to the quartz crystal do not only compensate for the crystal's natural temperature characteristics but also any other influences on the crystal such as ageing as well as from other oscillating circuit elements. In addition, the method also improves frequency sensitivity in inductance measurements. The experimental results show that through high temperature compensation improvement of the quartz crystal characteristics, this switching method theoretically enables a 2 pH resolution. It converts inductance to frequency in the range of 85-100 µH to 2-560 kHz.

  11. High Resolution Switching Mode Inductance-to-Frequency Converter with Temperature Compensation

    Directory of Open Access Journals (Sweden)

    Vojko Matko

    2014-10-01

    Full Text Available This article proposes a novel method for the temperature-compensated inductance-to-frequency converter with a single quartz crystal oscillating in the switching oscillating circuit to achieve better temperature stability of the converter. The novelty of this method lies in the switching-mode converter, the use of additionally connected impedances in parallel to the shunt capacitances of the quartz crystal, and two inductances in series to the quartz crystal. This brings a considerable reduction of the temperature influence of AT-cut crystal frequency change in the temperature range between 10 and 40 °C. The oscillator switching method and the switching impedances connected to the quartz crystal do not only compensate for the crystal’s natural temperature characteristics but also any other influences on the crystal such as ageing as well as from other oscillating circuit elements. In addition, the method also improves frequency sensitivity in inductance measurements. The experimental results show that through high temperature compensation improvement of the quartz crystal characteristics, this switching method theoretically enables a 2 pH resolution. It converts inductance to frequency in the range of 85–100 µH to 2–560 kHz.

  12. Radio-frequency Induction plasma modification effects of disperse systems based on mineral glass

    Science.gov (United States)

    Miftakhov, I. S.; Voznesensky, E. F.; Nagmutdinova, A. I.; Trofimov, A. V.; Sisoev, V. A.; Garifullina, A. R.; Krasina, I. V.

    2017-11-01

    In the article the possibility of use of high-frequency induction plasma discharge of low pressure as a tool for pre-processing the glass optical elements. Established effects of polishing, improve the adhesion of the glass elements to the polymer binder and the increase of the reflection coefficient.

  13. Determination of the High Frequency Inductance Profile of Surface Mounted Permanent Magnet Synchronous Motors

    DEFF Research Database (Denmark)

    Lu, Kaiyuan; Rasmussen, Peter Omand; Ritchie, Ewen

    2008-01-01

    ) synchronous motors. This paper presents an AC+DC measurement method for determination of the d-axis and q-axis high frequency inductance profiles of SMPM synchronous motors. This method uses DC currents to set a desired magnetic working point on the motor laminations, and then superimpose balanced small AC...... signals to measure the incremental a separate determination of the d, q inductance profiles as functions of the d, q currents. Experimental results on a commercial SMPM motor using the proposed method are presented in this paper....

  14. Instant centre frequency at anaesthetic induction--a new way to analyse sympathovagal balance.

    Science.gov (United States)

    de Souza Neto, Edmundo Pereira; Cerutti, Catherine; Loufoua, Joseph; Saroul, Christine; Chiari, Pascal; Custaud, Marc-Antoine; Lehot, Jean-Jacques

    2003-02-01

    The instant centre frequency (ICF) of RR interval has been proposed as a global index to analyse the sympathovagal interaction in the heart. The aim of this study was to assess the ICF during anaesthesia to test if it can reliably capture the neural control of the cardiovascular system. Twenty-four ASA II or III patients scheduled for cardiac surgery were included in the study. They were allocated in two groups: control, no treatment (group 1, n = 12), and beta-adrenergic blockade by atenolol (group 2, n = 12). Spectra of pulse interval series were computed with a time-frequency method and they were divided into: very low frequency (VLF, 0.000-0.040 Hz), low frequency (LF, 0.050-0.150 Hz) and high frequency (HF, 0.160-0.500 Hz). Normalized power was obtained by dividing the cumulative power within each frequency band (LF or HF) by the sum of LF and HF; the ratio of LF/HF was also calculated. Instant centre frequency is a time-varying parameter that the evolution along time of the gravity centrum of a local spectrum. All spectral indexes were recorded at the following time points: before induction, after induction and before intubation, during intubation, and after intubation. The atenolol group had lower normalized LF and the LF/HF ratio (P ICF was higher in atenolol group at all times. The ICF shifted towards HF frequency after induction and before intubation and shifted towards LF during intubation in both groups. The autonomic nervous system control on the heart through the interaction of sympathetic and parasympathetic reflex mechanisms could be studied by the ICF. The ICF may assess the autonomic cardiac modulation and may provide useful information for anaesthetic management.

  15. Determination of High-Frequency d- and q-axis Inductances for Surface-Mounted Permanent-Magnet Synchronous Machines

    DEFF Research Database (Denmark)

    Lu, Kaiyuan; Vetuschi, M.; Rasmussen, Peter Omand

    2010-01-01

    This paper presents a reliable method for the experimental determination of high-frequency d- and q -axis inductances for surface-mounted permanent-magnet synchronous machines (SMPMSMs). Knowledge of the high-frequency d- and q-axis inductances plays an important role in the efficient design...

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

    NARCIS (Netherlands)

    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

  17. The effects of extremely low frequency magnetic fields on mutation induction in mice

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, James W. [Department of Genetics, University of Leicester, Leicester LE1 7RH (United Kingdom); Haines, Jackie; Sienkiewicz, Zenon [Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot, Oxfordshire OX11 0RQ (United Kingdom); Dubrova, Yuri E., E-mail: yed2@le.ac.uk [Department of Genetics, University of Leicester, Leicester LE1 7RH (United Kingdom)

    2015-03-15

    Highlights: • The effects of 50 Hz magnetic fields on mutation induction in mice were analyzed. • The frequency of ESTR mutation was established in sperm and blood. • Exposure to 10–300 μT for 2 and 15 h did not result in mutation induction. • Mutagenic effects of 50 Hz magnetic fields are likely to be negligible. - Abstract: The growing human exposure to extremely low frequency (ELF) magnetic fields has raised a considerable concern regarding their genotoxic effects. The aim of this study was to evaluate the in vivo effects of ELF magnetic fields irradiation on mutation induction in the germline and somatic tissues of male mice. Seven week old BALB/c × CBA/Ca F{sub 1} hybrid males were exposed to 10, 100 or 300 μT of 50 Hz magnetic fields for 2 or 15 h. Using single-molecule PCR, the frequency of mutation at the mouse Expanded Simple Tandem Repeat (ESTR) locus Ms6-hm was established in sperm and blood samples of exposed and matched sham-treated males. ESTR mutation frequency was also established in sperm and blood samples taken from male mice exposed to 1 Gy of acute X-rays. The frequency of ESTR mutation in DNA samples extracted from blood of mice exposed to magnetic fields did not significantly differ from that in sham-treated controls. However, there was a marginally significant increase in mutation frequency in sperm but this was not dose-dependent. In contrast, acute exposure X-rays led to significant increases in mutation frequency in sperm and blood of exposed males. The results of our study suggest that, within the range of doses analyzed here, the in vivo mutagenic effects of ELF magnetic fields are likely to be minor if not negligible.

  18. The effects of extremely low frequency magnetic fields on mutation induction in mice

    International Nuclear Information System (INIS)

    Wilson, James W.; Haines, Jackie; Sienkiewicz, Zenon; Dubrova, Yuri E.

    2015-01-01

    Highlights: • The effects of 50 Hz magnetic fields on mutation induction in mice were analyzed. • The frequency of ESTR mutation was established in sperm and blood. • Exposure to 10–300 μT for 2 and 15 h did not result in mutation induction. • Mutagenic effects of 50 Hz magnetic fields are likely to be negligible. - Abstract: The growing human exposure to extremely low frequency (ELF) magnetic fields has raised a considerable concern regarding their genotoxic effects. The aim of this study was to evaluate the in vivo effects of ELF magnetic fields irradiation on mutation induction in the germline and somatic tissues of male mice. Seven week old BALB/c × CBA/Ca F 1 hybrid males were exposed to 10, 100 or 300 μT of 50 Hz magnetic fields for 2 or 15 h. Using single-molecule PCR, the frequency of mutation at the mouse Expanded Simple Tandem Repeat (ESTR) locus Ms6-hm was established in sperm and blood samples of exposed and matched sham-treated males. ESTR mutation frequency was also established in sperm and blood samples taken from male mice exposed to 1 Gy of acute X-rays. The frequency of ESTR mutation in DNA samples extracted from blood of mice exposed to magnetic fields did not significantly differ from that in sham-treated controls. However, there was a marginally significant increase in mutation frequency in sperm but this was not dose-dependent. In contrast, acute exposure X-rays led to significant increases in mutation frequency in sperm and blood of exposed males. The results of our study suggest that, within the range of doses analyzed here, the in vivo mutagenic effects of ELF magnetic fields are likely to be minor if not negligible

  19. Assessment of Crack Detection in Heavy-Walled Cast Stainless Steel Piping Welds Using Advanced Low-Frequency Ultrasonic Methods

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Michael T.; Crawford, Susan L.; Cumblidge, Stephen E.; Denslow, Kayte M.; Diaz, Aaron A.; Doctor, Steven R.

    2007-03-01

    Studies conducted at the Pacific Northwest National Laboratory in Richland, Washington, have focused on assessing the effectiveness and reliability of novel approaches to nondestructive examination (NDE) for inspecting coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the U.S. Nuclear Regulatory Commission on the effectiveness and reliability of advanced NDE methods as related to the inservice inspection of safety-related components in pressurized water reactors (PWRs). This report provides progress, recent developments, and results from an assessment of low frequency ultrasonic testing (UT) for detection of inside surface-breaking cracks in cast stainless steel reactor piping weldments as applied from the outside surface of the components. Vintage centrifugally cast stainless steel piping segments were examined to assess the capability of low-frequency UT to adequately penetrate challenging microstructures and determine acoustic propagation limitations or conditions that may interfere with reliable flaw detection. In addition, welded specimens containing mechanical and thermal fatigue cracks were examined. The specimens were fabricated using vintage centrifugally cast and statically cast stainless steel materials, which are typical of configurations installed in PWR primary coolant circuits. Ultrasonic studies on the vintage centrifugally cast stainless steel piping segments were conducted with a 400-kHz synthetic aperture focusing technique and phased array technology applied at 500 kHz, 750 kHz, and 1.0 MHz. Flaw detection and characterization on the welded specimens was performed with the phased array method operating at the frequencies stated above. This report documents the methodologies used and provides results from laboratory studies to assess baseline material noise, crack detection, and length-sizing capability for low-frequency UT in cast stainless steel piping.

  20. Development of radioactive waste disposal of high efficiency and safety. High-frequency induction melting system

    International Nuclear Information System (INIS)

    Kuchiki, Norikazu; Fukuda, Seishi; Kakuta, Toshiya; Satou, Kouji; Yamazaki, Seiichiro

    2007-01-01

    The amount of low level radioactive solid waste is expected to increase because of dismantling of nuclear power plants and nuclear science research facilities. Kawasaki Plant Systems, Ltd. has developed melting techniques for waste volume reduction on a pilot scale. This report gives an outline of R and D results for a high-frequency induction melting system using a nonconductive canister and Al-ring. (author)

  1. New And Existing Bridge Constructions - Increase of Fatigue Strength of Welded Joints by High Frequency Mechanical Impact Treatment

    Directory of Open Access Journals (Sweden)

    Ummenhofer Thomas

    2013-07-01

    Full Text Available Numerous studies at KIT prove that high frequency mechanical impact (HFMI treatment is an efficient method for increasing the fatigue strength of welded steel structures. Within different research projects it was found that HFMI-methods can be used successfully for new and existing structures in order to extend the fatigue life. This paper gives an overview of the current status of existing steel bridges in Germany regarding aspects like bridge age distributions and traffic loads. Based on that overview welded joints susceptible to fatigue failure are identified. Using component-like small scale specimens, HFMI-methods were investigated within the objective of implementing an effective application for new and existing structures. Applying the fatigue test data observed, existing design proposals are evaluated and design recommendations for HFMI-treated joints are given. As a result of the research work, a transfer into practice has been realized and different applications are illustrated using the example of bridge constructions made of steel.

  2. Modeling of High-Frequency Electromagnetic Effects on an Ironless Inductive Position Sensor

    CERN Document Server

    Danisi, Alessandro; Masi, Alessandro; Perriard, Yves

    2013-01-01

    The ironless inductive position sensor (I2PS) is a five-coil air-cored structure that senses the variation of flux linkage between supply and sense coils and relates it to the linear position of a moving coil. In air-cored structures, the skin and proximity effect can bring substantial variations of the electrical resistance, leading to important deviations from the low-frequency functioning. In this paper, an analysis of the effect of high-frequency phenomena on the I2PS functioning is described. The key-element is the modeling of the resistance as a function of the frequency, which starts from the analytical resolution of Maxwell's equations in the coil's geometry. The analysis is validated by means of experimental measurements on custom sensor coils. The resulting model is integrated with the existing low-frequency analysis and represents a complete tool for the design of an I2PS sensor, framing its electromagnetic behavior.

  3. Effect of residual stress relaxation by means of local rapid induction heating on stress corrosion cracking behavior and electrochemical characterization of welded Ti-6Al-4V alloy under slow strain rate test

    Science.gov (United States)

    Liu, Yan; Tang, Shawei; Liu, Guangyi; Sun, Yue; Hu, Jin

    2017-05-01

    In this study, a welded Ti-6Al-4V alloy was treated by means of local rapid induction heating in order to relax the residual stress existed in the weldment. The welded samples were heat treated at the different temperatures. The stress corrosion cracking behavior and electrochemical characterization of the as-welded samples before and after the post weld heat treatment as a function of residual stress were investigated. Electrochemical impedance spectroscopy measurements of the samples under slow strain rate test were performed in a LiCl-methanol solution. The results demonstrated that the residual stress in the as-welded sample was dramatically reduced after the post weld heat treatment, and the residual stress decreased with the increase in the heat treatment temperature. The stress corrosion cracking susceptibility and electrochemical activity of the as-welded sample were significantly reduced after the heat treatment due to the relaxation of the residual stress, which gradually decreased with the decreasing value of the residual stress distributed in the heat treated samples.

  4. Weld pool oscillation during gas tungsten arc welding

    Science.gov (United States)

    Xiao, You Hong

    The oscillation behavior of Gas Tungsten Arc (GTA) weld pools in mild steels Fe 360 and in austenitic stainless steel AISI 304 is considered. Special attention is given to the possibility of using the weld pool oscillation behavior as a sensor of weld pool geometry during welding, which is one of the objectives in adaptive control of the welding process. The topics discussed include the theoretical background of the oscillation phenomenon, the direct observation of weld pool oscillation, the experimental determination of the relation between the weld pool geometry and the oscillation frequency both under stationary arc conditions and under traveling arc conditions and the possibility of sensing the weld pool geometry, especially the weld pool penetration, by monitoring the oscillation frequency.

  5. Influence of operating frequency and coupling coefficient on the efficiency of microfabricated inductively coupled plasma sources

    International Nuclear Information System (INIS)

    Iza, F; Hopwood, J

    2002-01-01

    Microfabricated inductively coupled plasma (mICP) generators, operating at 690 and 818 MHz, have been constructed and characterized. The mICP consists of a single-turn coil that is 5 mm in diameter and a microfabricated matching network. Ion densities of ∼9x10 10 cm -3 in argon at 400 mTorr consuming only 1 W were obtained. This ion density is three times larger than previous mICP sources under the same conditions. The influence of the frequency of operation and the coupling coefficient on the power efficiency has also been studied. Contrary to what was observed in former generations of mICP sources operating at lower frequencies, the efficiency of the new mICP sources decreases as the frequency increases. A model that incorporates the electron inertia, the power dependence of the plasma resistance and the frequency dependence of the coil resistance agrees with the new experimental results as well as with the results of previous mICP sources. It was also observed that bringing the coil closer to the plasma increases the coupling coefficient of the ICP sources and thereby improves the efficiency of the device. The improvement in efficiency, however, is limited by the non-scalable plasma sheath width near the coil

  6. Low-frequency, high-density, inductively coupled plasma sources: Operation and applications

    Science.gov (United States)

    Xu, S.; Ostrikov, K. N.; Li, Y.; Tsakadze, E. L.; Jones, I. R.

    2001-05-01

    Operation regimes, plasma parameters, and applications of the low-frequency (˜500 kHz) inductively coupled plasma (ICP) sources with a planar external coil are investigated. It is shown that highly uniform, high-density (ne˜9×1012 cm-3) plasmas can be produced in low-pressure argon discharges with moderate rf powers. The low-frequency ICP sources operate in either electrostatic (E) or electromagnetic (H) regimes in a wide pressure range without any Faraday shield or an external multipolar magnetic confinement, and exhibit high power transfer efficiency, and low circuit loss. In the H mode, the ICP features high level of uniformity over large processing areas and volumes, low electron temperatures, and plasma potentials. The low-density, highly uniform over the cross-section, plasmas with high electron temperatures and plasma and sheath potentials are characteristic to the electrostatic regime. Both operation regimes offer great potential for various plasma processing applications. As examples, the efficiency of the low-frequency ICP for steel nitriding and plasma-enhanced chemical vapor deposition of hydrogenated diamond-like carbon (DLC) films, is demonstrated. It appears possible to achieve very high nitriding rates and dramatically increase micro-hardness and wear resistance of the AISI 304 stainless steel. It is also shown that the deposition rates and mechanical properties of the DLC films can be efficiently controlled by selecting the discharge operating regime.

  7. Transient plasma potential in pulsed dual frequency inductively coupled plasmas and effect of substrate biasing

    Directory of Open Access Journals (Sweden)

    Anurag Mishra

    2016-09-01

    Full Text Available An electron emitting probe in saturated floating potential mode has been used to investigate the temporal evolution of plasma potential and the effect of substrate RF biasing on it for pulsed dual frequency (2 MHz/13.56 MHz inductively coupled plasma (ICP source. The low frequency power (P2MHz has been pulsed at 1 KHz and a duty ratio of 50%, while high frequency power (P13.56MHz has been used in continuous mode. The substrate has been biased with a separate bias power at (P12.56MHz Argon has been used as a discharge gas. During the ICP power pulsing, three distinct regions in a typical plasma potential profile, have been identified as ‘initial overshoot’, pulse ‘on-phase’ and pulse ‘off-phase’. It has been found out that the RF biasing of the substrate significantly modulates the temporal evolution of the plasma potential. During the initial overshoot, plasma potential decreases with increasing RF biasing of the substrate, however it increases with increasing substrate biasing for pulse ‘on-phase’ and ‘off-phase’. An interesting structure in plasma potential profile has also been observed when the substrate bias is applied and its evolution depends upon the magnitude of bias power. The reason of the evolution of this structure may be the ambipolar diffusion of electron and its dependence on bias power.

  8. High Frequency Multiple Shoot Induction of Curculigo orchioides Gaertn.: Shoot Tip V/S Rhizome Disc

    Directory of Open Access Journals (Sweden)

    K. S. Nagesh

    2008-09-01

    Full Text Available Curculigo orchioides Gaertn. is an endangered medicinal plant with anticancer properties. The rhizome and tuberous roots of the plant have been used extensively in India in indigenous medicine. Due to its multiple uses, the demand for Curculigo orchioides is constantly on the rise; however, the supply is rather erratic and inadequate. Destructive harvesting, combined with habitat destruction in the form of deforestation has aggravated the problem. The plant is now considered ‘endangered’ in its natural habitat. Therefore, the need for conservation of this plant is crucial. Here, we describe a successful protocol for multiple shoot induction of C. orchioides using shoot tip and rhizome disc. We find that proximal rhizome discs are optimal for high frequency shoot bud formation than shoot tip and distal rhizome disc. We observed a synergistic effect between 6-benzylaminopurine (BAP and kinetin (KN (each at 1 mg/L on the regeneration of shoot buds from proximal rhizome disc than shoot tip explant. Optimum root induction was achieved on half-strength MS liquid medium supplemented with 1 mg/L of indole-3-butyric acid (IBA. The in vitro raised plantlets were acclimatized in green house and successfully transplanted to natural condition with 90% survival.

  9. Ultrasonic Stir Welding

    Science.gov (United States)

    Nabors, Sammy

    2015-01-01

    NASA Marshall Space Flight Center (MSFC) developed Ultrasonic Stir Welding (USW) to join large pieces of very high-strength metals such as titanium and Inconel. USW, a solid-state weld process, improves current thermal stir welding processes by adding high-power ultrasonic (HPU) energy at 20 kHz frequency. The addition of ultrasonic energy significantly reduces axial, frictional, and shear forces; increases travel rates; and reduces wear on the stir rod, which results in extended stir rod life. The USW process decouples the heating, stirring, and forging elements found in the friction stir welding process allowing for independent control of each process element and, ultimately, greater process control and repeatability. Because of the independent control of USW process elements, closed-loop temperature control can be integrated into the system so that a constant weld nugget temperature can be maintained during welding.

  10. 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).

  11. Inversion of multi-frequency electromagnetic induction data for 3D characterization of hydraulic conductivity

    Science.gov (United States)

    Brosten, Troy R.; Day-Lewis, Frederick D.; Schultz, Gregory M.; Curtis, Gary P.; Lane, John W.

    2011-01-01

    Electromagnetic induction (EMI) instruments provide rapid, noninvasive, and spatially dense data for characterization of soil and groundwater properties. Data from multi-frequency EMI tools can be inverted to provide quantitative electrical conductivity estimates as a function of depth. In this study, multi-frequency EMI data collected across an abandoned uranium mill site near Naturita, Colorado, USA, are inverted to produce vertical distribution of electrical conductivity (EC) across the site. The relation between measured apparent electrical conductivity (ECa) and hydraulic conductivity (K) is weak (correlation coefficient of 0.20), whereas the correlation between the depth dependent EC obtained from the inversions, and K is sufficiently strong to be used for hydrologic estimation (correlation coefficient of − 0.62). Depth-specific EC values were correlated with co-located K measurements to develop a site-specific ln(EC)–ln(K) relation. This petrophysical relation was applied to produce a spatially detailed map of K across the study area. A synthetic example based on ECa values at the site was used to assess model resolution and correlation loss given variations in depth and/or measurement error. Results from synthetic modeling indicate that optimum correlation with K occurs at ~ 0.5 m followed by a gradual correlation loss of 90% at 2.3 m. These results are consistent with an analysis of depth of investigation (DOI) given the range of frequencies, transmitter–receiver separation, and measurement errors for the field data. DOIs were estimated at 2.0 ± 0.5 m depending on the soil conductivities. A 4-layer model, with varying thicknesses, was used to invert the ECa to maximize available information within the aquifer region for improved correlations with K. Results show improved correlation between K and the corresponding inverted EC at similar depths, underscoring the importance of inversion in using multi-frequency EMI data for hydrologic

  12. Induction

    International Nuclear Information System (INIS)

    Serment G, J.; Brena V, M.

    2000-01-01

    At the incidence on biological systems, the ionizing radiation can affect so much its structural components as the genetic material since in a direct form or by the free radicals produced mainly the water radiolysis via (indirect effect). The alpha particles produce a great quantity of leisures in sites very near of them, by consequence results in a major RDB frequency. For establish the influence that would be the leisures concentration (specifically RDB) it was decided to research what occur when is irradiated with high LET corpuscular radiation and major power of ionization using for this alpha particles of an Americium 241 source and Escherichia coli stubs with different defects in reparation genes, recombination and protection to the radiation damage. (Author)

  13. Welding hazards

    International Nuclear Information System (INIS)

    Khan, M.A.

    1992-01-01

    Welding technology is advancing rapidly in the developed countries and has converted into a science. Welding involving the use of electricity include resistance welding. Welding shops are opened in residential area, which was causing safety hazards, particularly the teenagers and children who eagerly see the welding arc with their naked eyes. There are radiation hazards from ultra violet rays which irritate the skin, eye irritation. Welding arc light of such intensity could damage the eyes. (Orig./A.B.)

  14. Comparative Study of Time-Frequency Decomposition Techniques for Fault Detection in Induction Motors Using Vibration Analysis during Startup Transient

    Directory of Open Access Journals (Sweden)

    Paulo Antonio Delgado-Arredondo

    2015-01-01

    Full Text Available Induction motors are critical components for most industries and the condition monitoring has become necessary to detect faults. There are several techniques for fault diagnosis of induction motors and analyzing the startup transient vibration signals is not as widely used as other techniques like motor current signature analysis. Vibration analysis gives a fault diagnosis focused on the location of spectral components associated with faults. Therefore, this paper presents a comparative study of different time-frequency analysis methodologies that can be used for detecting faults in induction motors analyzing vibration signals during the startup transient. The studied methodologies are the time-frequency distribution of Gabor (TFDG, the time-frequency Morlet scalogram (TFMS, multiple signal classification (MUSIC, and fast Fourier transform (FFT. The analyzed vibration signals are one broken rotor bar, two broken bars, unbalance, and bearing defects. The obtained results have shown the feasibility of detecting faults in induction motors using the time-frequency spectral analysis applied to vibration signals, and the proposed methodology is applicable when it does not have current signals and only has vibration signals. Also, the methodology has applications in motors that are not fed directly to the supply line, in such cases the analysis of current signals is not recommended due to poor current signal quality.

  15. Energy Efficiency of Induction Motors Running Off Frequency Converters with Pulse-Width Voltage Modulation{sup 1}

    Energy Technology Data Exchange (ETDEWEB)

    Shvetsov, N. K., E-mail: elmash@em.ispu.ru [V. I. Lenin Ivanovo State Power University (Russian Federation)

    2016-11-15

    The results of calculations of the increase in losses in an induction motor with frequency control and different forms of the supply voltage are presented. The calculations were performed by an analytic method based on harmonic analysis of the supply voltage as well as numerical calculation of the electromagnetic processes by the finite-element method.

  16. Comparative energy consumption analyses of an ultra high frequency induction heating system for material processing applications

    Directory of Open Access Journals (Sweden)

    Taştan, Mehmet

    2015-09-01

    Full Text Available This study compares an energy consumption results of the TI-6Al-4V based material processing under the 900 kHz induction heating for different cases. By this means, total power consumption and energy consumptions per sample and amount have been analyzed. Experiments have been conducted with 900 kHz, 2.8 kW ultra-high frequency induction system. Two cases are considered in the study. In the first case, TI-6Al-4V samples have been heated up to 900 °C with classical heating method, which is used in industrial applications, and then they have been cooled down by water. Afterwards, the samples have been heated up to 600 °C, 650 °C and 700 °C respectively and stress relieving process has been applied through natural cooling. During these processes, energy consumptions for each defined process have been measured. In the second case, unlike the first study, can be used five different samples have been heated up to the various temperatures between 600 °C and 1120 °C and energy consumptions have been measured for these processes. Thereby, the effect of temperature increase on each sample on energy cost has been analyzed. It has been seen that as a result of heating the titanium bulk materials, which have been used in the experiment, with ultra high frequency induction, temperature increase also increases the energy consumption. But it has been revealed that the increase rate in the energy consumption is more than the increase rate of the temperature.En este estudio se comparan los consumos energéticos al procesar Ti-6Al-4V por inducción a 900 kHz. Se ha analizado la potencia total consumida y la energía consumida por muestra. Los experimentos se han realizado en un sistema de inducción de ultra alta frecuencia a 900 kHz, 2,8 kW. Se han considerado dos casos, en el primero se ha calentado Ti-6Al-4V a 900 °C por el método clásico usado en la industria y enfriado en agua; posteriormente las muestras se han calentado a 600, 650 y 700 °C y

  17. Frequency Count Attribute Oriented Induction of Corporate Network Data for Mapping Business Activity

    Directory of Open Access Journals (Sweden)

    Tanutama Lukas

    2014-03-01

    Full Text Available Companies increasingly rely on Internet for effective and efficient business communication. As Information Technology infrastructure backbone for business activities, corporate network connects the company to Internet and enables its activities globally. It carries data packets generated by the activities of the users performing their business tasks. Traditionally, infrastructure operations mainly maintain data carrying capacity and network devices performance. It would be advantageous if a company knows what activities are running in its network. The research provides a simple method of mapping the business activity reflected by the network data. To map corporate users’ activities, a slightly modified Attribute Oriented Induction (AOI approach to mine the network data was applied. The frequency of each protocol invoked were counted to show what the user intended to do. The collected data was samples taken within a certain sampling period. Samples were taken due to the enormous data packets generated. Protocols of interest are only Internet related while intranet protocols are ignored. It can be concluded that the method could provide the management a general overview of the usage of its infrastructure and lead to efficient, effective and secure ICT infrastructure.

  18. Frequency Count Attribute Oriented Induction of Corporate Network Data for Mapping Business Activity

    Science.gov (United States)

    Tanutama, Lukas

    2014-03-01

    Companies increasingly rely on Internet for effective and efficient business communication. As Information Technology infrastructure backbone for business activities, corporate network connects the company to Internet and enables its activities globally. It carries data packets generated by the activities of the users performing their business tasks. Traditionally, infrastructure operations mainly maintain data carrying capacity and network devices performance. It would be advantageous if a company knows what activities are running in its network. The research provides a simple method of mapping the business activity reflected by the network data. To map corporate users' activities, a slightly modified Attribute Oriented Induction (AOI) approach to mine the network data was applied. The frequency of each protocol invoked were counted to show what the user intended to do. The collected data was samples taken within a certain sampling period. Samples were taken due to the enormous data packets generated. Protocols of interest are only Internet related while intranet protocols are ignored. It can be concluded that the method could provide the management a general overview of the usage of its infrastructure and lead to efficient, effective and secure ICT infrastructure.

  19. Improved planar radio frequency inductively coupled plasma configuration in plasma immersion ion implantation

    International Nuclear Information System (INIS)

    Tang, D.L.; Fu, R.K.Y.; Tian, X.B.; Chu, P.K.

    2003-01-01

    Plasmas with higher density and better uniformity are produced using an improved planar radio frequency (rf) inductively coupled plasma configuration in plasma immersion ion implantation (PIII). An axial magnetic field is produced by external electromagnetic coils outside the discharge chamber. The rf power can be effectively absorbed by the plasma in the vicinity of the electron gyrofrequency due to the enhanced resonant absorption of electromagnetic waves in the whistler wave range, which can propagate nearly along the magnetic field lines thus greatly increases the plasma density. The plasma is confined by a longitudinal multipolar cusp magnetic field made of permanent magnets outside the process chamber. It can improve the plasma uniformity without significantly affecting the ion density. The plasma density can be increased from 3x10 9 to 1x10 10 cm -3 employing an axial magnetic field of several Gauss at 1000 W rf power and 5x10 -4 Torr gas pressure. The nonuniformity of the plasma density is less than 10% and can be achieved in a process chamber with a diameter of 600 mm. Since the plasma generation and process chambers are separate, plasma extinction due to the plasma sheath touching the chamber wall in high-energy PIII can be avoided. Hence, low-pressure, high-energy, and high-uniformity ion implantation can be accomplished using this setup

  20. The fracture strength of cryomilled 99.7 Al nanopowders consolidated by high frequency induction sintering

    International Nuclear Information System (INIS)

    El-Danaf, Ehab A; Almajid, Abdulhakim A; Soliman, Mahmoud S; Baig, Muneer

    2014-01-01

    Mechanical Attrition of metallic powders induces severe plastic deformation and consequently reduces the average grain size. Powders of 99.7 Al (45μm particle size), cryomilled for 7 hrs having a crystal size of ∼ 20 nm, were consolidated by high frequency induction sintering under a constant pressure of 50 MPa and at two temperatures of 500 and 550 °C for two sintering dwell times of 1 and 3 minutes at a constant heating rate of 400 °C/min. The bright field TEM image and X-ray line broadening technique, for the cryomilled powders, were used to measure-the crystallite size. Simple compression at an initial strain rate of 10 −4 s −1 was conducted at room temperature, 373 and 473 K, and the yield strength was documented and correlated with the sintering parameters. The as-received 99.7 Al powders-consolidated using one of the sintering parameters was used as a reference material to compare the mechanical properties. Hardness, density and crystal size of the consolidated sample, that gave the highest yield and fracture strength, were measured

  1. Study of electron-extraction characteristics of an inductively coupled radio-frequency plasma neutralizer

    Science.gov (United States)

    Jianwu, HE; Longfei, MA; Senwen, XUE; Chu, ZHANG; Li, DUAN; Qi, KANG

    2018-01-01

    Inductively coupled radio-frequency (RF) plasma neutralizer (RPN) is an insert-free device that can be employed as an electron source in electric propulsion applications. Electron-extraction characteristics of the RPN are related to the bulk plasma parameters and the device’s geometry. Therefore, the effects of different electron-extraction apertures and operational parameters upon the electron-extraction characteristics are investigated according to the global nonambipolar flow and sheath model. Moreover, these models can also be used to explain why the electron-extraction characteristics of the RPN strongly depend upon the formation of the anode spot. During the experimental study, two types of anode spots are observed. Each of them has unique characteristics of electron extraction. Moreover, the hysteresis of an anode spot is observed by changing the xenon volume-flow rates or the bias voltages. In addition, the rapid ignited method, gas-utilization factor, electron-extraction cost and other factors that need to be considered in the design of the RPN are also discussed.

  2. Hot pressing of nanocrystalline tantalum using high frequency induction heating and pulse plasma sintering

    Science.gov (United States)

    Jakubowicz, J.; Adamek, G.; Sopata, M.; Koper, J. K.; Siwak, P.

    2017-12-01

    The paper presents the results of nanocrystalline powder tantalum consolidation using hot pressing. The authors used two different heating techniques during hot pressing: high-frequency induction heating (HFIH) and pulse plasma sintering (PPS). A comparison of the structure, microstructure, mechanical properties and corrosion resistance of the bulk nanocrystalline tantalum obtained in both techniques was performed. The nanocrystalline powder was made to start from the microcrystalline one using the high-energy ball milling process. The nanocrystalline powder was hot-pressed at 1000 °C, whereas, for comparison, the microcrystalline powder was hot pressed up to 1500 °C for proper consolidation. The authors found that during hot pressing, the powder partially reacts with the graphite die covered by boron nitride, which facilitated punches and powder displacement in the die during densification. Tantalum carbide and boride in the nanocrystalline material was found, which can improve the mechanical properties. The hardness of the HFIH and PPS nanocrystalline tantalum was as high as 625 and 615 HV, respectively. The microstructure was more uniform in the PPS nanomaterial. The corrosion resistance in both cases deteriorated, in comparison to the microcrystalline material, while the PPS material corrosion resistance was slightly better than that of the HFIH one.

  3. Brazed Diamond Micropowder Bur Fabricated by Supersonic Frequency Induction Heating for Precision Machining

    Science.gov (United States)

    Ma, Bojiang; Lou, Jianpeng; Pang, Qian

    2014-04-01

    The common brazed diamond micropowder bur fabricated in a vacuum furnace produces an even brazing alloy surface. The small brazed diamond grits show low outcropping from the brazing alloy surface, and the chip space between them is small. The bur shows a low grinding efficiency and poor heat dissipation. In this study, a brazed diamond micropowder bur was fabricated by supersonic frequency induction heating. The method afforded a fluctuant surface on the brazing alloy. The brazed diamond grits with an outcropping height distributed uniformly on the fluctuant surface. The fluctuant surface showed a certain chip space. These characteristics of the tool increased the grinding efficiency and decreased the temperature of the grinding arc area. The roughness R a of the ceramic tile surface trimmed by the tool cylinder was between 0.09 and 0.12 μm. In the first 90 min, the decrease in the weight of the ceramic tile ground by the tool cylinder was higher than that ground by the tool fabricated in a vacuum furnace. When the ceramic tile was cylindrically ground, the temperature of the grinding arc area measured using a thermocouple remained below 70 °C.

  4. An analysis of the temperature distribution in the pipe bending using high frequency induction heating

    International Nuclear Information System (INIS)

    Fukue, Hisayoshi; Mochizuki, Yoji; Nakamura, Harushige; Kobo, Hiroshi; Nitta, Tetsuo; Kawakami, Kiyoshi

    1986-01-01

    A pipe bending apparatus has recently been developed by applying high frequency induction heating. However, the smaller the radius of pipe bending, the greater becomes the reduction in wall thickness and the ovality of the pipe form. This makes it impossible to manufacture pipe bending which will meet the nuclear pipe design code. In order to solve this problem it is crucial to obtain a temperature distributions in a pipe which is moving. It is calculated by giving the following boundary conditions : distribution of the heat generation rate, and that of heat transfer of cooling water. In the process of analyzing these distributions, the following results were obtained. (1) The distribution of the heat generation rate is determined by the sink of energy flux of Poynting vectors. The coil efficiency thus calculated was sixty percent. This figure accords with the test data. (2) The distribution of heat transfer coefficient of cooling water is mainly determined by the rate of liquid film heat transfer, but departure from nucleate boiling and dryout has to be taken into consideration. (3) TRUMP CODE is modified so that the temperature distribution in moving pipes can be calculated by taking the boundary conditions into account. The calculated results were in accordance with the test data. (author)

  5. 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...

  6. 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.…

  7. Ultra-high frequency induction energy effects on refractory oxides as applied to processing and immobilization of radioactive waste

    Science.gov (United States)

    Roach, Jay A.

    The application of ultra-high frequency induction melting of refractory oxides (i.e. borosilicate glass [BSG]) has been extensively investigated to determine the feasibility of developing and implementing an innovative inductively heated draining technique that is reliable and predictable. The primary purpose is for immobilizing highly radioactive waste streams resulting from reprocessing of spent nuclear fuel. This work has included development and validation of a numerical model, using ANSYS MultiPhysics software, as well as numerous proof-of-concept and pilot-scale experimental tests. The model is a steady state axially-symmetric geometry for a cylindrical water-cooled crucible that includes two separate induction energy sources operating at different frequencies. It accounts for the induction energy interactions, thermal conduction, convection, and radiation effects, as well as hydrodynamic phenomenon due to buoyancy effects. The material property models incorporated into the numerical model include temperature dependence up to 2,000°C of key parameters including density, specific heat, thermal conductivity, and electrical conductivity, which can vary by several orders of magnitude within the temperature variations seen. The model has been experimentally validated, and shown to provide excellent representation of steady state temperature distributions, convection cell configurations, and flow field velocities for molten low conductivity materials. Thus, it provides the capability to conduct parametric studies to understand operational sensitivities and geometry effects that determine the performance of the inductively heated draining device, including scale-up effects. Complementary experimental work has also been conducted to test the model predictions, and iteratively used to improve the model accuracy. However, the primary focus of the experimental efforts was to demonstrate the feasibility of the inductively heated draining technique for application to

  8. Mathematical Model and Computational Analysis of Selected Transient States of Cylindrical Linear Induction Motor Fed via Frequency Converter

    Directory of Open Access Journals (Sweden)

    Andrzej Rusek

    2008-01-01

    Full Text Available The mathematical model of cylindrical linear induction motor (C-LIM fed via frequency converter is presented in the paper. The model was developed in order to analyze numerically the transient states. Problems concerning dynamics of ac-machines especially linear induction motor are presented in [1 – 7]. Development of C-LIM mathematical model is based on circuit method and analogy to rotary induction motor. The analogy between both: (a stator and rotor windings of rotary induction motor and (b winding of primary part of C-LIM (inductor and closed current circuits in external secondary part of C-LIM (race is taken into consideration. The equations of C-LIM mathematical model are presented as matrix together with equations expressing each vector separately. A computational analysis of selected transient states of C-LIM fed via frequency converter is presented in the paper. Two typical examples of C-LIM operation are considered for the analysis: (a starting the motor at various static loads and various synchronous velocities and (b reverse of the motor at the same operation conditions. Results of simulation are presented as transient responses including transient electromagnetic force, transient linear velocity and transient phase current.

  9. Effect of Frequency and Spatial-Harmonics on Rotary and Linear Induction Motor Characteristics

    Science.gov (United States)

    1972-03-01

    A computer analysis is made of the effect of current and MMF airgap harmonics on the output characteristics of rotary and linear induction motors. The current harmonics accompanying thyristor-control operation are evaluated by Fourier analyzing the p...

  10. Experimental diagnostics and modeling of inductive phenomena at low frequencies in impedance spectra of proton exchange membrane fuel cells

    Science.gov (United States)

    Pivac, Ivan; Šimić, Boris; Barbir, Frano

    2017-10-01

    Representation of fuel cell processes by equivalent circuit models, involving resistance and capacitance elements representing activation losses on both anode and cathode in series with resistance representing ohmic losses, cannot capture and explain the inductive loop that may show up at low frequencies in Nyquist diagram representation of the electrochemical impedance spectra. In an attempt to explain the cause of the low-frequency inductive loop and correlate it with the processes within the fuel cell electrodes, a novel equivalent circuit model of a Proton Exchange Membrane (PEM) fuel cell has been proposed and experimentally verified here in detail. The model takes into account both the anode and the cathode, and has an additional resonant loop on each side, comprising of a resistance, capacitance and inductance in parallel representing the processes within the catalyst layer. Using these additional circuit elements, more accurate and better fits to experimental impedance data in the wide frequency range at different current densities, cell temperatures, humidity of gases, air flow stoichiometries and backpressures were obtained.

  11. 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.

  12. Resistance seam welding

    International Nuclear Information System (INIS)

    Schueler, A.W.

    1977-01-01

    The advantages and disadvantages of the resistance seam welding process are presented. Types of seam welds, types of seam welding machines, seam welding power supplies, resistance seam welding parameters and seam welding characteristics of various metals

  13. A finite-difference frequency-domain code for electromagnetic induction tomography

    International Nuclear Information System (INIS)

    Berryman, J.G.; Buettner, H.M.; Champagne, N.J.II.; Grant, J.B.; Sharpe, R.M.

    1998-01-01

    We are developing a new 3D code for application to electromagnetic induction tomography and applications to environmental imaging problems. We have used the finite-difference frequency- domain formulation of Beilenhoff et al. (1992) and the anisotropic PML (perfectly matched layer) approach (Berenger, 1994) to specify boundary conditions following Wu et al. (1997). PML deals with the fact that the computations must be done in a finite domain even though the real problem is effectively of infinite extent. The resulting formulas for the forward solver reduce to a problem of the form Ax = y, where A is a non-Hermitian matrix with real values off the diagonal and complex values along its diagonal. The matrix A may be either symmetric or nonsymmetric depending on details of the boundary conditions chosen (i.e., the particular PML used in the application). The basic equation must be solved for the vector x (which represents field quantities such as electric and magnetic fields) with the vector y determined by the boundary conditions and transmitter location. Of the many forward solvers that could be used for this system, relatively few have been thoroughly tested for the type of matrix encountered in our problem. Our studies of the stability characteristics of the Bi-CG algorithm raised questions about its reliability and uniform accuracy for this application. We have found the stability characteristics of Bi-CGSTAB [an alternative developed by van der Vorst (1992) for such problems] to be entirely adequate for our application, whereas the standard Bi-CG was quite inadequate. We have also done extensive validation of our code using semi-analytical results as well as other codes. The new code is written in Fortran and is designed to be easily parallelized, but we have not yet tested this feature of the code. An adjoint method is being developed for solving the inverse problem for conductivity imaging (for mapping underground plumes), and this approach, when ready, will

  14. Induction of chromosomal aberrations in human primary fibroblasts and immortalized cancer cells exposed to extremely-low-frequency electromagnetic fields

    International Nuclear Information System (INIS)

    Seyyedi, S. S.; Mozdarani, H.; Rezaei Tavirani, M.; Heydari, S.

    2010-01-01

    Rapidly increasing possibilities of exposure to environmental extremely low-frequency electromagnetic fields have become a topic of worldwide investigation. Epidemiological and laboratory studies suggest that exposure to extremely low-frequency electromagnetic fields may increase cancer risk therefore assessment of chromosomal damage in various cell lines might be of predictive value for future risk estimation. Materials and Methods: Primary cultures of fibroblasts from human skin biopsy were exposed to continuous extremely low-frequency electromagnetic fields (3, 50 and 60 Hz, sinusoidal, 3h, and 4 m T). Also immortalized cell lines, SW480, MCF-7 and 1321N1 were exposed to continuous extremely low-frequency electromagnetic fields (50 Hz, sinusoidal, 3 h, 4 m T). Metaphase plates Were prepared according to standard methods and stained in 5% Giemsa solution. Chromosomal aberrations of both chromosome and chromatid types were scored to evaluate the effects of extremely low-frequency electromagnetic fields on primary or established cell lines. Results: Results indicate that by increasing the frequency of extremely low-frequency electromagnetic fields, chromosomal aberrations were increased up to 7-fold above background levels in primary human fibroblast cells. In addition, continuous exposure to a 50 Hz electromagnetic field led to a significant increase in chromosomal aberrations in SW480, MCF-7 and 1321N1 cell lines compared to sham control. Conclusion: Results obtained indicate that extremely low-frequency electromagnetic fields has the potential for induction of chromosomal aberrations in all cell types.

  15. Measuring weld heat to evaluate weld integrity

    Energy Technology Data Exchange (ETDEWEB)

    Schauder, V., E-mail: schauder@hks-prozesstechnik.de [HKS-Prozesstechnik GmbH, Halle (Germany)

    2015-11-15

    Eddy current and ultrasonic testing are suitable for tube and pipe mills and have been used for weld seam flaw detection for decades, but a new process, thermography, is an alternative. By measuring the heat signature of the weld seam as it cools, it provides information about weld integrity at and below the surface. The thermal processes used to join metals, such as plasma, induction, laser, and gas tungsten arc welding (GTAW), have improved since they were developed, and they get better with each passing year. However, no industrial process is perfect, so companies that conduct research in flaw detection likewise continue to develop and improve the technologies used to verify weld integrity: ultrasonic testing (UT), eddy current testing (ET), hydrostatic, X-ray, magnetic particle, and liquid penetrant are among the most common. Two of these are used for verifying the integrity of the continuous welds such as those used on pipe and tube mills: UT and ET. Each uses a transmitter to send waves of ultrasonic energy or electrical current through the material and a receiver (probe) to detect disturbances in the flow. The two processes often are combined to capitalize on the strengths of each. While ET is good at detecting flaws at or near the surface, UT penetrates the material, detecting subsurface flaws. One drawback is that sound waves and electrical current waves have a specific direction of travel, or an alignment. A linear defect that runs parallel to the direction of travel of the ultrasonic sound wave or a flaw that is parallel to the coil winding direction of the ET probe can go undetected. A second drawback is that they don't detect cold welds. An alternative process, thermography, works in a different fashion: It monitors the heat of the material as the weld cools. Although it measures the heat at the surface, the heat signature provides clues about cooling activity deep in the material, resulting in a thorough assessment of the weld's integrity It

  16. Development of multi-frequency array induction logging (MAIL) tool. 3; Multi shuhasu array gata induction kenso tool (MAIL) no kaihatsu (genchi shiken data no ichijigen kaiseki). 3

    Energy Technology Data Exchange (ETDEWEB)

    Sato, T.; Osato, K.; Takasugi, S. [Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan); Uchida, T. [New Energy and Industrial Technology Development Organization, Tokyo, (Japan)

    1996-05-01

    A field test was carried out in 1995 on a deep-seated geothermal investigation and reduction well WDR (in Kakkonda, Shizuku-ishi, Iwate Prefecture) by utilizing a multi-frequency array induction logging tool which is under development by NEDO. This paper reports results of analyzing the acquired data. With the WDR wells, an investigation has been conducted to a drilling depth of 330 m. Three frequencies in a range from 3 to 24 kHz provided relatively good data, but data with 42 kHz had poor quality that cannot be utilized for the analysis. Precise device calibration is difficult on data acquired from three array type vertical component magnetometers (the difficulty may be due to a signal line from a transmitter passing on the magnetometer side). Because of this difficulty, analysis using one-dimensional inversion program was performed by using ratio of the amplitude for each frequency and phase difference as input data. The analysis allowed to have derived a result that corresponds to the ground bed structure. 5 refs., 8 figs., 3 tabs.

  17. Effect of narrow groove MAG welding oscillation parameters on weld formation

    Directory of Open Access Journals (Sweden)

    Yu LUO

    2017-02-01

    Full Text Available In order to solve the problem of narrow groove wall fusion, improving the weld formation, the welding test of different oscillation width and frequency is carried out by adopting the narrow high-speed swing MAG welding torch. On the basis of measuring the macro metallographic to determine the weld cross section size, the curve fitting of the variation trend of the weld section size with the swing width and the swing frequency is carried out. The effect of the high speed swing arc narrow groove welding MAG parameters on weld formation is studied. The results show that increasing the swing width or frequency can reduce the weld penetration and increase lateral wall penetration; when the swinging width makes side spacing greater than -05 mm and less than 1 mm, good weld forming will be gained; when the oscillation frequency increases to more than 5 Hz, weld finger penetration can be eliminated, but when it is above 9 Hz, increasing the swing frequency cannot cause obvious change of the dimension of weld. The effects of these oscillating parameters on weld formation can provide guidance for the selection of welding parameters.

  18. 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…

  19. Low frequency pseudo-inductive phenomenon at novel glass microcapillaries exhibiting non-ohmic behaviour

    Czech Academy of Sciences Publication Activity Database

    Silver, Barry Richard; Holub, Karel; Mareček, Vladimír

    2013-01-01

    Roč. 110, NOV 2013 (2013), s. 801-808 ISSN 0013-4686 R&D Projects: GA ČR GA13-04630S Institutional support: RVO:61388955 Keywords : rectification * impedance * pseudo-inductive Subject RIV: CG - Electrochemistry Impact factor: 4.086, year: 2013

  20. Type A sleeve pipeline repair heated by induction

    Energy Technology Data Exchange (ETDEWEB)

    Souza, F.B.G. [Petrobras, Rio de Janeiro (Brazil). TransPetro; Meniconi, M.L.C. [Petrobras, Rio de Janeiro (Brazil). Centro de Pesquisas; Ghizoni, G. [JAMO Equipamentos LTDA, Jaragua do Sul (Brazil); Frainer, V.J.; Betanzos, J.T. [Univ. Federal do Rio Grande do Sul, Rio Grande (Brazil)

    2004-07-01

    Many pipeline operators routinely use full encirclement welded sleeves in their pipeline repair programs. Type A welded sleeves can be installed on a pipeline without the need for additional welding to the carrier pipe. This paper described a laboratory test conducted to measure the mechanical interference between a pipe and a type A welded sleeve that was applied using an induction heating method. Interference was evaluated through the use of strain gages installed after application of the sleeve over the pipe section. The induction heating equipment was used to pre-heat the steel tubes prior to primer epoxy application, as well as to obtain the heat-shrinkable anticorrosion coating. Induction heating took approximately 2 minutes. The sleeve was then cut longitudinally in diametric positions with an abrasive disc while signals were monitored by an automatic signal conditioner and a portable computer. Acquired data were plotted as a time versus deformation diagram. Results showed that the sleeve adhered well to the pipe. No bulging was detected. It was concluded that adequate machinery and assembling techniques are needed to ensure proper placement of the sleeve over the pipe as well as an even stress distribution. Future designs for induction coils should be developed to improve frequency rates. 8 refs., 7 figs.

  1. Dual Resonant Frequencies Effects on an Induction-Based Oil Palm Fruit Sensor

    Directory of Open Access Journals (Sweden)

    Noor Hasmiza Harun

    2014-11-01

    Full Text Available As the main exporter in the oil palm industry, the need to improve the quality of palm oil has become the main interest among all the palm oil millers in Malaysia. To produce good quality palm oil, it is important for the miller to harvest a good oil palm Fresh Fruit Bunch (FFB. Conventionally, the main reference used by Malaysian harvesters is the manual grading standard published by the Malaysian Palm Oil Board (MPOB. A good oil palm FFB consists of all matured fruitlets, aged between 18 to 21 weeks of antheses (WAA. To expedite the harvesting process, it is crucial to implement an automated detection system for determining the maturity of the oil palm FFB. Various automated detection methods have been proposed by researchers in the field to replace the conventional method. In our preliminary study, a novel oil palm fruit sensor to detect the maturity of oil palm fruit bunch was proposed. The design of the proposed air coil sensor based on the inductive sensor was further investigated mainly in the context of the effect of coil diameter to improve its sensitivity. In this paper, the sensitivity of the inductive sensor was further examined with a dual flat-type shape of air coil. The dual air coils were tested on fifteen samples of fruitlet from two categories, namely ripe and unripe. Samples were tested within 20 Hz to 10 MHz while evaluations on both peaks were done separately before the gap between peaks was analyzed. A comparative analysis was conducted to investigate the improvement in sensitivity of the induction-based oil palm fruit sensor as compared to previous works. Results from the comparative study proved that the inductive sensor using a dual flat-type shape air coil has improved by up to 167%. This provides an indication in the improvement in the coil sensitivity of the palm oil fruit sensor based on the induction concept.

  2. A high frequency active voltage doubler in standard CMOS using offset-controlled comparators for inductive power transmission.

    Science.gov (United States)

    Lee, Hyung-Min; Ghovanloo, Maysam

    2013-06-01

    In this paper, we present a fully integrated active voltage doubler in CMOS technology using offset-controlled high speed comparators for extending the range of inductive power transmission to implantable microelectronic devices (IMD) and radio-frequency identification (RFID) tags. This active voltage doubler provides considerably higher power conversion efficiency (PCE) and lower dropout voltage compared to its passive counterpart and requires lower input voltage than active rectifiers, leading to reliable and efficient operation with weakly coupled inductive links. The offset-controlled functions in the comparators compensate for turn-on and turn-off delays to not only maximize the forward charging current to the load but also minimize the back current, optimizing PCE in the high frequency (HF) band. We fabricated the active voltage doubler in a 0.5-μm 3M2P std . CMOS process, occupying 0.144 mm(2) of chip area. With 1.46 V peak AC input at 13.56 MHz, the active voltage doubler provides 2.4 V DC output across a 1 kΩ load, achieving the highest PCE = 79% ever reported at this frequency. In addition, the built-in start-up circuit ensures a reliable operation at lower voltages.

  3. Magnetic fields and uniformity of radio frequency power deposition in low-frequency inductively coupled plasmas with crossed internal oscillating currents

    International Nuclear Information System (INIS)

    Tsakadze, E.L.; Ostrikov, K.; Tsakadze, Z.L.; Vladimirov, S.V.; Xu, S.

    2004-01-01

    Radial and axial distributions of magnetic fields in a low-frequency (∼460 kHz) inductively coupled plasma source with two internal crossed planar rf current sheets are reported. The internal antenna configuration comprises two orthogonal sets of eight alternately reconnected parallel and equidistant copper litz wires in quartz enclosures and generates three magnetic (H z , H r , and H φ ) and two electric (E φ and E r ) field components at the fundamental frequency. The measurements have been performed in rarefied and dense plasmas generated in the electrostatic (E) and electromagnetic (H) discharge modes using two miniature magnetic probes. It is shown that the radial uniformity and depth of the rf power deposition can be improved as compared with conventional sources of inductively coupled plasmas with external flat spiral ('pancake') antennas. Relatively deeper rf power deposition in the plasma source results in more uniform profiles of the optical emission intensity, which indicates on the improvement of the plasma uniformity over large chamber volumes. The results of the numerical modeling of the radial magnetic field profiles are found in a reasonable agreement with the experimental data

  4. Welding complex

    Energy Technology Data Exchange (ETDEWEB)

    Lebedev, V.K.; Kuchuk-Yatsenko, S.I.; Sakharnov, V.A.; Galyan, B.A.; Krivenko, V.G.; Asoyants, G.B.

    1992-10-27

    A welding complex for construction of a continuous underwater pipeline is adapted to be installed aboard a ship. The complex includes a welding machine positionable at a joint of the pipeline with a pipe section to be welded, burr-removing trimmers positionable coaxially with the pipeline for displacement relative to the pipeline in the joint area, and a support device for the end part of the pipeline. A rotatably mounted holding device for setting, holding, and retaining the pipe section to be welded, the welding machine, and the trimmers is axially aligned with the end part of the pipeline. An accumulator is provided for storing and delivering successive pipe sections at a loading position laterally offset from the common axis of the pipeline and of the pipe section to be welded to it. The holding device includes a platform movable along the common axis of the pipeline and of the pipe section to be welded to it by a resistance butt welding machine, and a plate with a means for carrying the pipe section to be welded which is mounted on a pivot carried by the platform for rotation between the loading position and the aligning position. The welding complex of the invention provides for implementing resistance butt welding in construction of continuous underwater pipelines and ensures the accuracy of alignment and permanence of the gap between the edges being welded. The welding complex's structure allows handling of longer pipe sections, thus reducing the overall number of joints to be welded. 7 figs.

  5. Frequency-tuning radiofrequency plasma source operated in inductively-coupled mode under a low magnetic field

    Science.gov (United States)

    Takahashi, Kazunori; Nakano, Yudai; Ando, Akira

    2017-07-01

    A radiofrequency (rf) inductively-coupled plasma source is operated with a frequency-tuning impedance matching system, where the rf frequency is variable in the range of 20-50 MHz and the maximum power is 100 W. The source consists of a 45 mm-diameter pyrex glass tube wound by an rf antenna and a solenoid providing a magnetic field strength in the range of 0-200 Gauss. A reflected rf power for no plasma case is minimized at the frequency of ˜25 MHz, whereas the frequency giving the minimum reflection with the high density plasma is about 28 MHz, where the density jump is observed when minimizing the reflection. A high density argon plasma above 1× {{10}12} cm-3 is successfully obtained in the source for the rf power of 50-100 W, where it is observed that an external magnetic field of a few tens of Gauss yields the highest plasma density in the present configuration. The frequency-tuning plasma source is applied to a compact and high-speed silicon etcher in an Ar-SF6 plasma; then the etching rate of 8~μ m min-1 is obtained for no bias voltage to the silicon wafer, i.e. for the case that a physical ion etching process is eliminated.

  6. Experimental measurement of the electron energy distribution function in the radio frequency electron cyclotron resonance inductive discharge

    International Nuclear Information System (INIS)

    Chung, ChinWook; Kim, S.S.; Chang, H.Y.

    2004-01-01

    Recently, the existence of electron cyclotron resonance (ECR) in a weakly magnetized inductively coupled plasma (MICP) has been evidenced [ChinWook Chung et al., Phys. Rev. Lett. 80, 095002 (2002)]. The distinctive feature of the ECR effect in the MICP is efficacious heating of low-energy electrons. In the present paper, electron heating characteristics in the MICP have been investigated by observing electron energy distribution function dependencies on various external parameters such as gas pressure, driving frequency, and rf power (electron density). It is found that the ECR effect on electron heating becomes enhanced with decreasing pressure or increasing driving frequency. The ECR heating becomes weak at high rf power due to the electron-electron collisions

  7. Modelling high frequency phenomena in the rotor of induction motors under no-load test conditions

    International Nuclear Information System (INIS)

    Boglietti, Aldo; Bottauscio, Oriano.; Chiampi, Mario; Lazzari, Mario

    2003-01-01

    The paper aims to deep the electromagnetic phenomena in the rotor of induction motors produced during the no-load test by the high-order harmonics of the spatial distribution of magnetic flux. The analysis is carried out by a flux driven finite element procedure, which can take into account the hysteresis of magnetic material, the induced currents in rotor cage and the eddy currents in the laminations. The computed results, including losses and local waveforms of electrical and magnetic quantities, are finally discussed

  8. 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…

  9. Formation of structure and properties in welded joints of oil line pipes

    Science.gov (United States)

    Vyboishchik, L. M.; Ioffe, A. V.

    2013-01-01

    The effect of welding and heat treatment modes on mechanical properties and corrosion resistance of welded joints of oil line pipes is studied. It is shown that high-frequency welding followed by high-temperature annealing provides strength and corrosion properties in welds of pipes from low-carbon low-alloy steels at the level of the welded metal.

  10. Frequency, suppressive capacity, recruitment and induction mechanisms of regulatory T cells in sinonasal squamous cell carcinoma and nasal inverted papilloma.

    Directory of Open Access Journals (Sweden)

    Hongfei Lou

    Full Text Available Sinonasal squamous cell carcinoma (SSCC and nasal inverted papilloma (NIP represent the predominant type of malignant and benign tumors in sinonasal tract, respectively. CD4+ CD25+ Foxp3+ natural regulatory T (Treg cells might play critical role(s in the suppression of anti-tumor immune response and thus shed light on tumor progression from benign to malignant.This study aimed to evaluate the frequency and suppressive capacity of Treg cells in SSCC compared to NIP and further to explore the underlying mechanisms.Frequencies of Treg, Th1 and Th2 cells were evaluated by flow cytometry in tissue homogenate and peripheral blood from 31 SSCC patients, 32 NIP patients and 35 normal controls. Treg cells were tested for regulatory function by co-culture with effector T cells. CCR4 and its ligands, CCL22 and CCL17, were analyzed by flow cytometry and Luminex, respectively. The chemoattractant properties of CCR4/CCL22 and CCR4/CCL17 for Treg cells were assessed using the Boyden chamber technique, to elucidate the potential mechanisms of Treg recruitment in tumor microenvironment. Treg cells induction via TGF-β was assessed with transwells after local CD4+ Foxp3+ T cells were assessed by immunohistochemistry and TGF-β concentration was measured by Luminex.Tumor-infiltrating Treg cells increased significantly from normal to NIP to SSCC (P ≤ 0.001 for normal vs. NIP and P = 0.004 for NIP vs. SSCC. Significantly elevated frequency and enhanced suppression capacity of circulating Treg cells in SSCC were detected compared to NIP and healthy controls, concomitant with Th1 decrease and Th2 increase. Apparently increased CCL22 attracted CCR4-expressing Treg cells to tumor microenvironment in SSCC, compared to NIP. SSCC produced significantly more TGF-β than NIP and thus possessed greater potential for Treg cell induction.Frequency and suppressive capacity of Treg cells enhanced with progression of malignancy from NIP to SSCC. Circulating Treg cells were

  11. 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)

  12. Development of multi-frequency array induction logging (MAIL) tool. Part 4; Multi shuhasu array gata induction kenso (MAIL) tool no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Sato, T.; Otsuka, K.; Takasugi, S. [GERD Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan); Uchida, T. [New Energy and Industrial Technology Development Organization, Tokyo, (Japan)

    1997-05-27

    NEDO is now carrying out `the deep-seated geothermal resource survey` with the aim of surveying deep geothermal resource lying 3,000m below sea level. `The development of resistivity use investigation technology` being carried out as element technology for this survey conducts well surveys and earth surface-well surveys using the drilled deep wells. By analyzing these surveys together with electromagnetic method surveys including the MT method carried out on the earth surface, the survey was aimed at grasping in high resolution resistivity structures from the shallow underground to the deep underground. The multi-frequency array induction logging being researched as the well survey is a method to grasp resistivity structures within a radius of several meters of the well using the electromagnetic logging method. The paper reported the field test conducted this time using the improved tool. A comparison of the data obtained in the test with the results of the normal logging showed consistency, and therefore, it showed that the tool itself fully grasped responses from strata. 3 refs., 5 figs., 1 tab.

  13. Design of spherical electron gun for ultra high frequency, CW power inductive output tube

    International Nuclear Information System (INIS)

    Kaushik, Meenu; Joshi, L. M.

    2016-01-01

    Inductive Output Tube (IOT) is an amplifier that usually operates in UHF range. It is an electron tube whose basic structure is similar to conventional vacuum devices. This device is widely used in broadcast applications but is now being explored for scientific applications also specifically, particle accelerators and fusion plasma heating purposes. The paper describes the design approach of a spherical gridded electron gun of a 500 MHz, 100 kW CW power IOT. The electron gun structure has been simulated and optimized for operating voltage and current of 40kV and 3.5 A respectively. The electromagnetic analysis of this spherical electron gun has been carried out in CST and TRAK codes.

  14. [New welding processes and health effects of welding].

    Science.gov (United States)

    La Vecchia, G Marina; Maestrelli, Piero

    2011-01-01

    This paper describes some of the recent developments in the control technology to enhance capability of Pulse Gas Metal Arc Welding. Friction Stir Welding (FSW) processing has been also considered. FSW is a new solid-state joining technique. Heat generated by friction at the rotating tool softens the material being welded. FSW can be considered a green and energy-efficient technique without deleterious fumes, gas, radiation, and noise. Application of new welding processes is limited and studies on health effects in exposed workers are lacking. Acute and chronic health effects of conventional welding have been described. Metal fume fever and cross-shift decline of lung function are the main acute respiratory effects. Skin and eyes may be affected by heat, electricity and UV radiations. Chronic effects on respiratory system include chronic bronchitis, a benign pneumoconiosis (siderosis), asthma, and a possible increase in the incidence of lung cancer. Pulmonary infections are increased in terms of severity, duration, and frequency among welders.

  15. Evaluation of power transfer efficiency for a high power inductively coupled radio-frequency hydrogen ion source

    Science.gov (United States)

    Jain, P.; Recchia, M.; Cavenago, M.; Fantz, U.; Gaio, E.; Kraus, W.; Maistrello, A.; Veltri, P.

    2018-04-01

    Neutral beam injection (NBI) for plasma heating and current drive is necessary for International Thermonuclear Experimental reactor (ITER) tokamak. Due to its various advantages, a radio frequency (RF) driven plasma source type was selected as a reference ion source for the ITER heating NBI. The ITER relevant RF negative ion sources are inductively coupled (IC) devices whose operational working frequency has been chosen to be 1 MHz and are characterized by high RF power density (˜9.4 W cm-3) and low operational pressure (around 0.3 Pa). The RF field is produced by a coil in a cylindrical chamber leading to a plasma generation followed by its expansion inside the chamber. This paper recalls different concepts based on which a methodology is developed to evaluate the efficiency of the RF power transfer to hydrogen plasma. This efficiency is then analyzed as a function of the working frequency and in dependence of other operating source and plasma parameters. The study is applied to a high power IC RF hydrogen ion source which is similar to one simplified driver of the ELISE source (half the size of the ITER NBI source).

  16. Robotic Vision for Welding

    Science.gov (United States)

    Richardson, R. W.

    1986-01-01

    Vision system for robotic welder looks at weld along axis of welding electrode. Gives robot view of most of weld area, including yet-unwelded joint, weld pool, and completed weld bead. Protected within welding-torch body, lens and fiber bundle give robot closeup view of weld in progress. Relayed to video camera on robot manipulator frame, weld image provides data for automatic control of robot motion and welding parameters.

  17. Properties and Rapid Sintering of Nanostructured WC and WC-TiAl by the High Frequency Induction Heating

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Bong-Won; Oh, Seung-Jin; Shon, In-Jin [Chonbuk National University, Junju (Korea, Republic of); Kim, Byung-Su [Korea Institute of Geoscience and Mineral Resources, Daejeon (Korea, Republic of); Yoon, Jin-Kook [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2016-03-15

    In the case of cemented WC, Ni or Co is added as a binder for the formation of composite structures. However, the high cost and the low hardness of Ni or Co, and the low corrosion resistance of the WC-Ni and WC-Co cermets have generated interest in alternative binder phases recently. In this study, TiAl was used as a novel binder and consolidated by the high frequency induction heated sintering (HFIHS) method. Nanopowders of WC and TiAl were made by high energy ball milling. Highly dense WC and WC-10 vol% TiAl with a relative density of up to 99% were obtained within one min by HFIHS under a pressure of 80 MPa. The addition of TiAl to WC enhanced the toughness without great decrease of hardness due to the crack deflection and nanostructured phase.

  18. 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.

  19. Passively damped vibration welding system and method

    Science.gov (United States)

    Tan, Chin-An; Kang, Bongsu; Cai, Wayne W.; Wu, Tao

    2013-04-02

    A vibration welding system includes a controller, welding horn, an anvil, and a passive damping mechanism (PDM). The controller generates an input signal having a calibrated frequency. The horn vibrates in a desirable first direction at the calibrated frequency in response to the input signal to form a weld in a work piece. The PDM is positioned with respect to the system, and substantially damps or attenuates vibration in an undesirable second direction. A method includes connecting the PDM having calibrated properties and a natural frequency to an anvil of an ultrasonic welding system. Then, an input signal is generated using a weld controller. The method includes vibrating a welding horn in a desirable direction in response to the input signal, and passively damping vibration in an undesirable direction using the PDM.

  20. Control of Microstructures and the Practical Properties of API X80 Grade Heavy-Wall High-Frequency Electric Resistance-Welded Pipe with Excellent Low-Temperature Toughness

    Science.gov (United States)

    Goto, Sota; Nakata, Hiroshi; Toyoda, Shunsuke; Okabe, Takatoshi; Inoue, Tomohiro

    2017-10-01

    This paper describes development of heavy-walled API X80 grade high-frequency electric resistance-welded (HFW) line pipes and conductor-casing pipes with wall thicknesses up to 20.6 mm. A fine bainitic-ferrite microstructure, which is preferable for low-temperature toughness, was obtained by optimizing the carbon content and applying the thermomechanical controlled hot-rolling process. As a result, the Charpy ductile-brittle transition temperature (DBTT) was well below 227 K (-46 °C) in the base metal of the HFW line pipe. When the controlled hot-rolling ratio (CR) was increased from 23 to 48 pct, the area average grain size decreased from 15 to 8 μm. The dependence of CTOD properties on CR was caused by the largest grain which is represented by the area average grain size. No texture development due to the increase of CR from 23 to 48 pct was observed. In addition, because controlled in-line heat treatment of the longitudinal weld seam also produced the fine bainitic-ferrite microstructure at the weld seam, DBTT was lower than 227 K (-46 °C) at the weld portion. The developed pipes showed good girth weldability without preheat treatment, and fracture in the tensile test initiated from the base metal in all cases.

  1. Non-contact multi-frequency magnetic induction spectroscopy system for industrial-scale bio-impedance measurement

    International Nuclear Information System (INIS)

    O'Toole, M D; Marsh, L A; Davidson, J L; Tan, Y M; Armitage, D W; Peyton, A J

    2015-01-01

    Biological tissues have a complex impedance, or bio-impedance, profile which changes with respect to frequency. This is caused by dispersion mechanisms which govern how the electromagnetic field interacts with the tissue at the cellular and molecular level. Measuring the bio-impedance spectra of a biological sample can potentially provide insight into the sample’s properties and its cellular structure. This has obvious applications in the medical, pharmaceutical and food-based industrial domains. However, measuring the bio-impedance spectra non-destructively and in a way which is practical at an industrial scale presents substantial challenges. The low conductivity of the sample requires a highly sensitive instrument, while the demands of industrial-scale operation require a fast high-throughput sensor of rugged design. In this paper, we describe a multi-frequency magnetic induction spectroscopy (MIS) system suitable for industrial-scale, non-contact, spectroscopic bio-impedance measurement over a bandwidth of 156 kHz–2.5 MHz. The system sensitivity and performance are investigated using calibration and known reference samples. It is shown to yield rapid and consistently sensitive results with good long-term stability. The system is then used to obtain conductivity spectra of a number of biological test samples, including yeast suspensions of varying concentration and a range of agricultural produce, such as apples, pears, nectarines, kiwis, potatoes, oranges and tomatoes. (paper)

  2. Application of Passivity-Based Control and Time-Frequency Representation in a Doubly Fed Induction Generator System

    Directory of Open Access Journals (Sweden)

    Yingpei Liu

    2015-01-01

    Full Text Available In order to improve the performance of a doubly fed induction generator (DFIG system, we put forward a high performance nonlinear passivity-based control (PBC method on DFIG. Firstly, we build a PBC mathematical model for DFIG. We design the passive controller for the inner loop in the control system based on passivity theory. Then we calculate the rotor’s control voltages which are modulated afterwards to pulse to control the rotor side converter. The maximal wind energy capture is effectively realized. The rotor speed and DFIG currents fast track their expected values. The independent regulation of the stator active power and reactive power is achieved. Finally we perform simulations to verify the effectiveness of the proposed method. Furthermore, we employ the Wigner-Ville distribution (WVD and continuous wavelet transform (CWT as two time-frequency representation methods to indicate that the proposed method in the paper performs well from the perspective of energy distribution in time and frequency domain.

  3. Studies of an inductively coupled negative hydrogen ion radio frequency source through simulations and experiments

    International Nuclear Information System (INIS)

    Bandyopadhyay, M.

    2004-01-01

    In the frame work of a development project for ITER neutral beam injection system a radio frequency (RF) driven negative hydrogen (H-/D-) ion source, (BATMAN ion source) is developed which is designed to produce several 10s of ampere of H-/D- beam current. This PhD work has been carried out to understand and optimize BATMAN ion source. The study has been done with the help of computer simulations, modeling and experiments. The complete three dimensional Monte-Carlo computer simulation codes have been developed under the scope of this PhD work. A comprehensive description about the volume production and the surface production of H- ions is presented in the thesis along with the study results obtained from the simulations, modeling and the experiments. One of the simulations is based on the volume production of H- ions, where it calculates the density profile of the vibrationally excited H2 molecules, the density profile of H- ions and the transport probability of those H- ions along the source axis towards the grid. The other simulation studies the transport of those H- ions which are produced on the surface of the plasma grid. It is expected that if there is a plasma flow in the source, the transport of plasma components (molecules and ions) would be influenced. Experimentally it is observed that there is a convective plasma flow exists in the ion source. A transverse magnetic filter field which is present near the grid inside the ion source reduces the flow velocity. Negative ions and electrons have the same sign of charge; therefore the electrons are co-extracted with the negative ions through the grid system, which is not desirable. It is observed that a magnetic field near the grid, magnetized the electrons and therefore reduce the co-extracted electron current. It is also observed experimentally that if the plasma grid is biased positively with respect to the source body, the electron density near the plasma grid is reduced and therefore the co

  4. Studies of an inductively coupled negative hydrogen ion radio frequency source through simulations and experiments

    Energy Technology Data Exchange (ETDEWEB)

    Bandyopadhyay, M.

    2004-08-24

    In the frame work of a development project for ITER neutral beam injection system a radio frequency (RF) driven negative hydrogen (H-/D-) ion source, (BATMAN ion source) is developed which is designed to produce several 10s of ampere of H-/D- beam current. This PhD work has been carried out to understand and optimize BATMAN ion source. The study has been done with the help of computer simulations, modeling and experiments. The complete three dimensional Monte-Carlo computer simulation codes have been developed under the scope of this PhD work. A comprehensive description about the volume production and the surface production of H- ions is presented in the thesis along with the study results obtained from the simulations, modeling and the experiments. One of the simulations is based on the volume production of H- ions, where it calculates the density profile of the vibrationally excited H2 molecules, the density profile of H- ions and the transport probability of those H- ions along the source axis towards the grid. The other simulation studies the transport of those H- ions which are produced on the surface of the plasma grid. It is expected that if there is a plasma flow in the source, the transport of plasma components (molecules and ions) would be influenced. Experimentally it is observed that there is a convective plasma flow exists in the ion source. A transverse magnetic filter field which is present near the grid inside the ion source reduces the flow velocity. Negative ions and electrons have the same sign of charge; therefore the electrons are co-extracted with the negative ions through the grid system, which is not desirable. It is observed that a magnetic field near the grid, magnetized the electrons and therefore reduce the co-extracted electron current. It is also observed experimentally that if the plasma grid is biased positively with respect to the source body, the electron density near the plasma grid is reduced and therefore the co

  5. Structure–property relationship in a 960 MPa grade ultrahigh strength low carbon niobium–vanadium microalloyed steel: The significance of high frequency induction tempering

    International Nuclear Information System (INIS)

    Xie, Z.J.; Fang, Y.P.; Han, G.; Guo, H.; Misra, R.D.K.; Shang, C.J.

    2014-01-01

    The present study describes the microstructure and precipitation behavior in an ultra-high strength low carbon niobium–vanadium microalloyed steel that was processed by quenching and high frequency induction tempering. Ultrahigh yield strength of ∼1000 MPa with high elongation of ∼15% and high low temperature toughness of 55 J (half thickness) at −40 °C was obtained after quenching from austenitization at 900 °C for 30 min, and tempering at 600 °C for 15 min by induction reheating with a reheating rate of ∼50 °C/s. While the yield strength increase on tempering was similar for both induction reheating and conventional reheating (electrical resistance reheating), there was ∼100% increase in low temperature toughness in induction reheated steel compared to the conventional reheating process. The underlying reason for the increase in toughness was attributed to the transformation of cementite film observed in conventional reheating and tempering to nanoscale cementite in induction reheating and tempering. The precipitation of nanoscale carbides is believed to significantly contribute to ultra-high strength, good ductility, and high toughness in the high frequency induction reheating and tempering process

  6. TIG welding power supply with improved efficiency

    Directory of Open Access Journals (Sweden)

    Сергій Володимирович Гулаков

    2015-03-01

    Full Text Available In the article, the influence of the DC component of the welding current during TIG (Tungsten Inert Gas welding is discussed. Known methods of DC current cancellation are reviewed, such as capacitor bank or diode/thyristor network insertion in the secondary circuit of the welding transformer. A new method of controlling the magnitude and shape of the TIG welding current is proposed. The idea is to insert a controlled voltage source in the secondary circuit of the welding transformer. This controlled voltage source is realized using a full-bridge voltage source inverter (VSI. VSI control system design issues are discussed. VSI is controlled by a three-level hysteretic current controller, while current reference is generated using lookup table driven by PLL (Phase Locked Loop locked to the mains frequency. Simulation results are shown. The proposed topology of TIG power supply allows to provide magnitude and shape control of the welding current, with the limitation that its DC component must be zero. Thus, some capabilities of professional AC-TIG welders are obtained using substantially lower cost components: VSI built using high-current low voltage MOSFETs with control system based on 32-bit ARM microcontroller. The use of proposed TIG welding power supply will eliminate the DC component of the welding current, improve welding transformer’s power factor and improve welding technology by increasing the welding arc stability

  7. 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…

  8. Determination of Elements and Carbon Content of Stainless Steel Welded Pipeline

    Directory of Open Access Journals (Sweden)

    Pavel Hudeček

    2016-01-01

    Full Text Available Find out defects or problems of welds are not so simple from time to time. Specially, if weld has been made in rough environmental conditions like high temperature, dusty wind and humidity. It is important to assure have good conditions to realize basic step of welding. For welding, have been used welding procedures specification and procedure qualification record. However, difficult conditions, documentations rightness or human errors are always here. Common weld defects like cracks, porosity, lack of penetration and distortion can compromise the strength of the base metal, as well as the integrity of the weld. According of site inspection, there were suspicion of inclusions, leaker or segregation in root of weld. Surface treatment after welding and keep the intervals between single welds to not overheat the pipes. To recognize those suspicions, mechanical testing around weld joint, determination of carbon content and inductively coupled plasma atomic emission spectroscopy will be done.

  9. Induction of a:T mutations is dependent on cellular environment but independent of mutation frequency and target gene location.

    Science.gov (United States)

    Ukai, Akiko; Ishimaru, Konomi; Ouchida, Rika; Mori, Hiromi; Kano, Chie; Moritan, Toshiyuki; Wang, Ji-Yang

    2008-12-01

    Based on its substrate specificity, activation-induced cytidine deaminase can directly induce C:G mutations in Ig genes. However the origin of A:T mutations, which occur in a similar proportion in germinal center (GC) B cells, is unclear. Genetic evidence suggests that the induction of A:T mutations requires the components of the mismatch repair system and DNA polymerase eta (POLH). We found that fibroblasts and GC B cells expressed similar levels of the mismatch repair components, but nonetheless the fibroblasts failed to generate a significant proportion of A:T mutations in a GFP reporter gene even after POLH overexpression. To investigate whether the ability to generate A:T mutations is dependent on the cellular environment (i.e., GC B cell or fibroblast) or the target gene (i.e., Ig or GFP), we developed a mutation detection system in a human GC-like cell line. We introduced a GFP gene with a premature stop codon into Ramos cells and compared the activation-induced cytidine deaminase-induced mutations in the endogenous V(H) and the transgenic GFP genes. Remarkably, a high proportion of A:T mutations was induced in both genes. Ectopic expression of POLH did not further increase the proportion of A:T mutations but diminished the strand bias of these mutations that is normally observed in V(H) genes. Intriguingly, the total mutation frequency in the GFP gene was consistently one-fifth of that in the V(H) gene. These results demonstrate that the ability to generate A:T mutations is dependent on the GC B cell environment but independent of the mutation frequency and target gene location.

  10. Complexity of the ultraviolet mutation frequency response curve in Escherichia coli B/r: SOS induction, one-lesion and two-lesion mutagenesis

    International Nuclear Information System (INIS)

    Doudney, C.O.

    1976-01-01

    Three distinct sections of the ultraviolet mutation frequency response (MFR) curve toward tryptophan prototrophy have been demonstrated in Escherichia coli B/r WP2 trp thy and its uvrA derivative in log-phase growth in minimal medium. The initial section, which appears fluence-squared, may reflect the necessity, if mutation is to result, for induction of two lesions, one located within the potentially mutated genetic locus and the other damaging deoxyribonucleic acid replication and resulting in induction of the error-prone SOS repair function. A second linear section is ascribed to the continued induction, after exposure above that sufficient for complete SOS expression, of isolated lesions which lead to mutation in potentially mutated loci. The third section demonstrates an increased rate of mutagenesis and suggests the induction of two lesions in proximity which result in additional mutations. Split-exposure studies support the inducible nature of the SOS function and suggest that mutation frequency decline (MFD) is due to excision resulting from or related to the prevention of SOS induction by inhibition of protein synthesis. Preirradiation tryptophan starvation of the uvr + strain for 30 min decreases MFR in the first and second sections of the curve. Reduction of MFR in the third section requires more prestarvation time and is blocked by nalidixic acid. The decreased MFR of the first and second sections is ascribed to promotion of postirradiation MFD based on excision and that of the third section to completion of the chromosome during the prestarvation period

  11. Saturation Ion Current Densities in Inductively Coupled Hydrogen Plasma Produced by Large-Power Radio Frequency Generator

    Science.gov (United States)

    Wang, Songbai; Lei, Guangjiu; Bi, Zhenhua; Ghomi, H.; Yang, Size; Liu, Dongping

    2016-09-01

    An experimental investigation of the saturation ion current densities (Jions) in hydrogen inductively coupled plasma (ICP) produced by a large-power (2-32 kW) radio frequency (RF) generator is reported, then some reasonable explanations are given out. With the increase of RF power, the experimental results show three stages: in the first stage (2-14 kW), the electron temperature will rise with the increase of RF power in the ICP, thus, the Jions increases continually as the electron temperature rises in the ICP. In the second stage (14-20 kW), as some H- ions lead to the mutual neutralization (MN), the slope of Jions variation firstly decreases then increases. In the third stage (20-32 kW), both the electronic detachment (ED) and the associative detachment (AD) in the ICP result in the destruction of H- ions, therefore, the increased amplitude of the Jions in the third stage is weaker than the one in the first stage. In addition, with the equivalent transformer model, we successfully explain that the Jions at different radial locations in ICP has the same rule. Finally, it is found that the Jions has nothing to do with the outer/inner puffing gas pressure ratio, which is attributed to the high-speed movement of hydrogen molecules. supported by the National Magnetic Confinement Fusion Science Program of China (Nos. 2011GB108011 and 2010GB103001), the Major International (Regional) Project Cooperation and Exchanges of China (No. 11320101005) and the Startup Fund from Fuzhou University (No. 510071)

  12. The effect of dielectric top lids on materials processing in a low frequency inductively coupled plasma (LF-ICP) reactor

    Science.gov (United States)

    Lim, J. W. M.; Chan, C. S.; Xu, L.; Xu, S.

    2014-08-01

    The advent of the plasma revolution began in the 1970's with the exploitation of plasma sources for anisotropic etching and processing of materials. In recent years, plasma processing has gained popularity, with research institutions adopting projects in the field and industries implementing dry processing in their production lines. The advantages of utilizing plasma sources would be uniform processing over a large exposed surface area, and the reduction of toxic emissions. This leads to reduced costs borne by manufacturers which could be passed down as consumer savings, and a reduction in negative environmental impacts. Yet, one constraint that plagues the industry would be the control of contaminants in a plasma reactor which becomes evident when reactions are conducted in a clean vacuum environment. In this work, amorphous silicon (a-Si) thin films were grown on glass substrates in a low frequency inductively coupled plasma (LF-ICP) reactor with a top lid made of quartz. Even though the chamber was kept at high vacuum ( 10-4 Pa), it was evident through secondary ion mass spectroscopy (SIMS) and Fourier-transform infra-red spectroscopy (FTIR) that oxygen contaminants were present. With the aid of optical emission spectroscopy (OES) the contaminant species were identified. The design of the LF-ICP reactor was then modified to incorporate an Alumina (Al2O3) lid. Results indicate that there were reduced amounts of contaminants present in the reactor, and that an added benefit of increased power transfer to the plasma, improving deposition rate of thin films was realized. The results of this study is conclusive in showing that Al2O3 is a good alternative as a top-lid of an LF-ICP reactor, and offers industries a solution in improving quality and rate of growth of thin films.

  13. Optimization of vibratory welding process parameters using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pravin Kumar; Kumar, S. Deepak; Patel, D.; Prasad, S. B. [National Institute of Technology Jamshedpur, Jharkhand (India)

    2017-05-15

    The current investigation was carried out to study the effect of vibratory welding technique on mechanical properties of 6 mm thick butt welded mild steel plates. A new concept of vibratory welding technique has been designed and developed which is capable to transfer vibrations, having resonance frequency of 300 Hz, into the molten weld pool before it solidifies during the Shielded metal arc welding (SMAW) process. The important process parameters of vibratory welding technique namely welding current, welding speed and frequency of the vibrations induced in molten weld pool were optimized using Taguchi’s analysis and Response surface methodology (RSM). The effect of process parameters on tensile strength and hardness were evaluated using optimization techniques. Applying RSM, the effect of vibratory welding parameters on tensile strength and hardness were obtained through two separate regression equations. Results showed that, the most influencing factor for the desired tensile strength and hardness is frequency at its resonance value, i.e. 300 Hz. The micro-hardness and microstructures of the vibratory welded joints were studied in detail and compared with those of conventional SMAW joints. Comparatively, uniform and fine grain structure has been found in vibratory welded joints.

  14. [Study on the arc spectral information for welding quality diagnosis].

    Science.gov (United States)

    Li, Zhi-Yong; Gu, Xiao-Yan; Li, Huan; Yang, Li-Jun

    2009-03-01

    Through collecting the spectral signals of TIG and MIG welding arc with spectrometer, the arc light radiations were analyzed based on the basic theory of plasma physics. The radiation of welding arc distributes over a broad range of frequency, from infrared to ultraviolet. The arc spectrum is composed of line spectra and continuous spectra. Due to the variation of metal density in the welding arc, there is great difference between the welding arc spectra of TIG and MIG in both their intensity and distribution. The MIG welding arc provides more line spectra of metal and the intensity of radiation is greater than TIG. The arc spectrum of TIG welding is stable during the welding process, disturbance factors that cause the spectral variations can be reflected by the spectral line related to the corresponding element entering the welding arc. The arc spectrum of MIG welding will fluctuate severely due to droplet transfer, which produces "noise" in the line spectrum aggregation zone. So for MIG welding, the spectral zone lacking spectral line is suitable for welding quality diagnosis. According to the characteristic of TIG and MIG, special spectral zones were selected for welding quality diagnosis. For TIG welding, the selected zone is in ultraviolet zone (230-300 nm). For MIG welding, the selected zone is in visible zone (570-590 nm). With the basic theory provided for welding quality diagnosis, the integral intensity of spectral signal in the selected zone of welding process with disturbing factor was studied to prove the theory. The results show that the welding quality and disturbance factors can be diagnosed with good signal to noise ratio in the selected spectral zone compared with signal in other spectral zone. The spectral signal can be used for real-time diagnosis of the welding quality.

  15. Precision welding unit

    International Nuclear Information System (INIS)

    Wanke, R.

    1982-01-01

    The advantages of mechanized orbital-welding in TIG-pulse-technique are exact calculated heat input welding data adapted the certain welding position, reproducibility, high quality standard, lower physical, requirements of the operator. (orig.)

  16. 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...

  17. WELDING PROCESS

    Science.gov (United States)

    Zambrow, J.; Hausner, H.

    1957-09-24

    A method of joining metal parts for the preparation of relatively long, thin fuel element cores of uranium or alloys thereof for nuclear reactors is described. The process includes the steps of cleaning the surfaces to be jointed, placing the sunfaces together, and providing between and in contact with them, a layer of a compound in finely divided form that is decomposable to metal by heat. The fuel element members are then heated at the contact zone and maintained under pressure during the heating to decompose the compound to metal and sinter the members and reduced metal together producing a weld. The preferred class of decomposable compounds are the metal hydrides such as uranium hydride, which release hydrogen thus providing a reducing atmosphere in the vicinity of the welding operation.

  18. 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...

  19. Influence of shielding gas pressure on welding characteristics in CO2 laser-MIG hybrid welding process

    Science.gov (United States)

    Chen, Yanbin; Lei, Zhenglong; Li, Liqun; Wu, Lin

    2006-01-01

    The droplet transfer behavior and weld characteristics have been investigated under different pressures of shielding gas in CO2 laser and metal inert/active gas (laser-MIG) hybrid welding process. The experimental results indicate that the inherent droplet transfer frequency and stable welding range of conventional MIG arc are changed due to the interaction between CO2 laser beam and MIG arc in laser-MIG hybrid welding process, and the shielding gas pressure has a crucial effect on welding characteristics. When the pressure of shielding gas is low in comparison with MIG welding, the frequency of droplet transfer decreases, and the droplet transfer becomes unstable in laser-MIG hybrid welding. So the penetration depth decreases, which shows the characteristic of unstable hybrid welding. However, when the pressure of shielding gas increases to a critical value, the hybrid welding characteristic is changed from unstable hybrid welding to stable hybrid welding, and the frequency of droplet transfer and the penetration depth increase significantly.

  20. 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.

  1. Ultrasonic testing of austenitic stainless steel welds

    International Nuclear Information System (INIS)

    Nishino, Shunichi; Hida, Yoshio; Yamamoto, Michio; Ando, Tomozumi; Shirai, Tasuku.

    1982-05-01

    Ultrasonic testing of austenitic stainless steel welds has been considered difficult because of the high noise level and remarkable attenuation of ultrasonic waves. To improve flaw detectability in this kind of steel, various inspection techniques have been studied. A series of tests indicated: (1) The longitudinal angle beam transducers newly developed during this study can detect 4.8 mm dia. side drilled holes in dissimilar metal welds (refraction angle: 55 0 from SUS side, 45 0 from CS side) and in cast stainless steel welds (refraction angle: 45 0 , inspection frequency: 1 MHz). (2) Cracks more than 5% t in depth in the heat affected zones of fine-grain stainless steel pipe welds can be detected by the 45 0 shear wave angle beam method (inspection frequency: 2 MHz). (3) The pattern recognition method using frequency analysis technology was presumed useful for discriminating crack signals from spurious echoes. (author)

  2. A High Frequency (HF) Inductive Power Transfer Circuit for High Temperature Applications Using SiC Schottky Diodes

    Science.gov (United States)

    Jordan, Jennifer L.; Ponchak, George E.; Spry, David J.; Neudeck, Philip G.

    2018-01-01

    Wireless sensors placed in high temperature environments, such as aircraft engines, are desirable to reduce the mass and complexity of routing wires. While communication with the sensors is straight forward, providing power wirelessly is still a challenge. This paper introduces an inductive wireless power transfer circuit incorporating SiC Schottky diodes and its operation from room temperature (25 C) to 500 C.

  3. Singular and combined effects of thought suppression and anxiety induction on frequency of threatening thoughts: An experimental investigation

    NARCIS (Netherlands)

    Cougle, J.R.; Smits, J.A.J.; Lee, H.J.; Powers, M.B.; Telch, M.J.

    2005-01-01

    The suppression of unwanted thoughts has been hypothesized to play an important role in the maintenance of clinical disorders such as OCD and PTSD. The present study sought to examine the singular and combined effects of thought suppression instructions and anxiety induction (as induced by an

  4. 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.…

  5. 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

  6. Welding and cutting

    International Nuclear Information System (INIS)

    Drews, P.; Schulze Frielinghaus, W.

    1978-01-01

    This is a survey, with 198 literature references, of the papers published in the fields of welding and cutting within the last three years. The subjects dealt with are: weldability of the materials - Welding methods - Thermal cutting - Shaping and calculation of welded joints - Environmental protection in welding and cutting. (orig.) [de

  7. 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.

  8. An Improved Flux Observer for Field-Oriented Control of Induction Motors Based on Dual Second-Order Generalized Integrator Frequency-Locked Loop

    DEFF Research Database (Denmark)

    Xin, Zhen; Zhao, Rende; Blaabjerg, Frede

    2017-01-01

    and performance of the DSOGI-FLL based flux estimation method are analyzed in comparison with the SOGI-FLL, demonstrating its improved dynamic response. Simulations and experimental results on an 11-kW three-phase induction motor verify the excellent performance of the proposed DSOGI-FLL based flux estimation......Flux estimation is of great importance for high-performance motor drives. In order to improve flux estimation accuracy and reduce system complexity, a new flux estimation method based on Second-Order Generalized Integrator Frequency-Locked Loop (SOGI-FLL) was presented recently. Compared...

  9. Quality status display for a vibration welding process

    Science.gov (United States)

    Spicer, John Patrick; Abell, Jeffrey A.; Wincek, Michael Anthony; Chakraborty, Debejyo; Bracey, Jennifer; Wang, Hui; Tavora, Peter W.; Davis, Jeffrey S.; Hutchinson, Daniel C.; Reardon, Ronald L.; Utz, Shawn

    2017-11-28

    A method includes receiving, during a vibration welding process, a set of sensory signals from a collection of sensors positioned with respect to a work piece during formation of a weld on or within the work piece. The method also includes receiving control signals from a welding controller during the process, with the control signals causing the welding horn to vibrate at a calibrated frequency, and processing the received sensory and control signals using a host machine. Additionally, the method includes displaying a predicted weld quality status on a surface of the work piece using a status projector. The method may include identifying and display a quality status of a suspect weld. The laser projector may project a laser beam directly onto or immediately adjacent to the suspect welds, e.g., as a red, green, blue laser or a gas laser having a switched color filter.

  10. Study of interference in power supply for induction motors by variable frequency drivers; Estudo de interferencias na alimentacao eletrica de motores de inducao por inversores de frequencia

    Energy Technology Data Exchange (ETDEWEB)

    Sousa, Andre Luis de Oliveira e; Silva, Marcos Morais da [Centro Universitario de Belo Horizonte (UniBH), MG (Brazil)], e-mails: alosousa@gmail.com, marcosmoraisdasilva@hotmail.com; Pires, Igor Amariz [Universidade Federal de Minas Gerais (PPGEE/UFMG), Belo Horizonte, MG (Brazil). Dept. de Engenharia de Eletronica], e-mail: iap@ufmg.br

    2012-07-01

    First of all, this work went into an exploratory study which shows the variety of factors that the induction motors are submitted for being driven by frequency inverters. It's target was to address the leading technical aspects of the induction motors cage, and also, to discuss the influences of the inverters about the motor characteristics such as reflection voltage, common mode of noise, rise-time, and so on. On the top of it, this work have had a deep study about the interferences from installation and the distance between the frequency inverter and electric motor such as the aggravation of these factors for both the inverter-motor system and for electrical systems. They are magnetically linked to this system by a bunch of wires and cables. Also, some solutions about electric motor's manufacturers are also showed. Inverters, wire's suppliers and insulation materials have sought in order to get a great interaction between the electric motor and frequency inverter to avoid disturbing the system. Not only for themselves but also for the adjacent systems. Once we had faced it's subject, we can define that the factors here presented can directly interfere with the engine's life or lead it into problems with the electrical systems, if installed next to the drive by a frequency inverter. As it is a kind of trigger that only had got the confidence of the industries recently, regarding to the replacement of DC motors, many companies that provide it, are not technically ready to correctly specify the whole set, in order avoid the interference generated as it was well showed in this work. (author)

  11. Laser weld jig

    Science.gov (United States)

    Van Blarigan, Peter; Haupt, David L.

    1982-01-01

    A system is provided for welding a workpiece (10, FIG. 1) along a predetermined weld line (12) that may be of irregular shape, which includes the step of forming a lip (32) on the workpiece to extend parallel to the weld line, and moving the workpiece by engaging the lip between a pair of rotatable members (34, 36). Rotation of one of the members at a constant speed, causes the workpiece to move so that all points on the weld line sequentially pass a fixed point in space (17) at a constant speed, so that a laser welding beam can be directed at that fixed point to form a weld along the weld line. The workpiece can include a reuseable jig (24) forming the lip, and with the jig constructed to detachably hold parts (22, 20) to be welded at a position wherein the weld line of the parts extends parallel to the lip on the jig.

  12. Investigation of Nd:YAG pulsed laser dissimilar welding of AISI 4340 and AISI 316L stainless steels on weld geometry and mechanical properties

    Science.gov (United States)

    Sufizadeh, A. R.; Akbari Mousavi, S. A. A.

    2017-12-01

    In this paper, laser welding of 316L and AISI 4340 steel is studied. Studies are focused on the effects of laser parameters on the depth and width of the welds. The results show that increasing in pulse energy and frequency will increase the weld depth and the weld width. The calculation of effective peak power density related to the welded joints results in optimum operating welding parameters with full penetration and proper dimensions and strengths. The tensile strength values of the full penetrated weldments are greater than the tensile strength values of AISI 316 base metal. The effects of laser parameters on weld grain size and HAZ size were investigated. The results show that the weld grain size and HAZ size increase with pulse energy and frequency.

  13. Wind turbines using self-excited three-phase induction generators: an innovative solution for voltage-frequency control

    Science.gov (United States)

    Brudny, J. F.; Pusca, R.; Roisse, H.

    2008-08-01

    A considerable number of communities throughout the world, most of them isolated, need hybrid energy solutions either for rural electrification or for the reduction of diesel use. Despite several research projects and demonstrations which have been conducted in recent years, wind-diesel technology remains complex and much too costly. Induction generators are the most robust and common for wind energy systems but this option is a serious challenge for electrical regulation. When a wind turbine is used in an off-grid configuration, either continuously or intermittently, precise and robust regulation is difficult to attain. The voltage parameter regulation option, as was experienced at several remote sites (on islands and in the arctic for example), is a safe, reliable and relatively simple technology, but does not optimize the wave quality and creates instabilities. These difficulties are due to the fact that no theory is available to describe the system, due to the inverse nature of the problem. In order to address and solve the problem of the unstable operation of this wind turbine generator, an innovative approach is described, based on a different induction generator single phase equivalent circuit.

  14. Automatic welding of fuel elements

    International Nuclear Information System (INIS)

    Briola, J.

    1958-01-01

    The welding process depends on the type of fuel element, the can material and the number of cartridges to be welded: - inert-gas welding (used for G2 and the 1. set of EL3), - inert atmosphere arc welding (used for welding uranium and zirconium), - electronic welding (used for the 2. set of EL3 and the tank of Proserpine). (author) [fr

  15. Diffusion welding

    International Nuclear Information System (INIS)

    Daniault, J.; Gillet, R.

    1969-01-01

    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) [fr

  16. Comparative study of laminar and turbulent flow model with different operating parameters for radio frequency-inductively coupled plasma torch working at 3  MHz frequency at atmospheric pressure

    International Nuclear Information System (INIS)

    Punjabi, Sangeeta B.; Sahasrabudhe, S. N.; Das, A. K.; Joshi, N. K.; Mangalvedekar, H. A.; Kothari, D. C.

    2014-01-01

    This paper provides 2D comparative study of results obtained using laminar and turbulent flow model for RF (radio frequency) Inductively Coupled Plasma (ICP) torch. The study was done for the RF-ICP torch operating at 50 kW DC power and 3 MHz frequency located at BARC. The numerical modeling for this RF-ICP torch is done using ANSYS software with the developed User Defined Function. A comparative study is done between laminar and turbulent flow model to investigate how temperature and flow fields change when using different operating conditions such as (a) swirl and no swirl velocity for sheath gas flow rate, (b) variation in sheath gas flow rate, and (c) variation in plasma gas flow rate. These studies will be useful for different material processing applications

  17. Transition Frequencies and Negative Resistance of Inductively Terminated CMOS Buffer Cell and Application in MMW LC VCO

    Directory of Open Access Journals (Sweden)

    S. M. Rezaul Hasan

    2010-01-01

    looking into the source of the buffer cell changes sign. Possible limiting frequencies of oscillation are determined based on resonators formed by a grounded gate inductor and a parasitic capacitance at the gate of the negative resistance buffer cell. The range of frequencies of oscillation of this negative resistance buffer cell for variations in the different circuit parameters/elements is explored. Following this, a millimeter wave (MMW oscillator is simulated using the IBM 130 nm CMOS process technology which can operate at 70 GHz. High-frequency MOSFET model was used for these simulations. The cell had an extremely low power dissipation of under 3 mW. Extensive Monte Carlo simulations were carried out for manufacturability analysis considering up to 50% variation in process and geometrical parameters, supply voltage, and ambient temperature. Noise analysis and a simulated estimate of the phase noise in an MMW LC VCO application is also reported.

  18. Ion energy distribution functions in inductively coupled radio-frequency discharges emdash Mixtures of Cl2/BCl3/Ar

    International Nuclear Information System (INIS)

    Nichols, C.A.; Woodworth, J.R.; Hamilton, T.W.

    1998-01-01

    We have used a gridded energy analyzer to measure positive ion energy distributions and fluxes at the grounded electrode of a high-density rf discharge. We present details of ion energies and fluxes in discharges containing mixtures of chlorine, boron trichloride and argon. These feedstock mixtures have been used extensively in the patterning of metal films for semiconductor interconnects. Our experiments were carried out in a Gaseous Electronics Conference Reference Cell which had been modified to produce inductively coupled discharges. The 15-cm-diam bottom electrode was grounded for these experiments. Stainless steel, anodized aluminum, and silicon were used as bottom electrode materials to understand the effects of various chamber boundary conditions on the ion energy parameters. In most cases, the ion energy distributions had a single peak, well separated from zero energy with a 1.0 endash 3.0 eV full width at half maximum. These peaks were typically centered at 12 endash 16 eV, with ion energy increasing as pressure decreased. Addition of BCl 3 to a Cl 2 discharge resulted in a reduction of total ion flux of more than a factor of 2, e.g., from 5 to 2.5 mA/cm 2 (20 mTorr, 200 W). The ion fluxes decreased with increasing pressures in BCl 3 /Cl 2 mixtures, while increasing with pressure in pure Cl 2 discharges. Addition of Ar to several mixtures of BCl 3 /Cl 2 changed the ion fluxes and mean ion energies by less than 15%. At high pressures or low inductive rf powers, the distributions can split into two overlapping peaks separated by as much as 8 eV. This splitting is indicative of capacitive coupling between the rf coil and the discharge. Insertion of a Faraday shield between the coil and the discharge removed most of the splitting. copyright 1998 American Vacuum Society. thinsp

  19. Development of coupling systems at the hybrid frequency for the non-inductive current generation inside a tokamak; Developpement de coupleurs a la frequence hybride pour la generation non inductive du courant dans un tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Berio, S. [Association Euratom-CEA, Centre d`Etudes Nucleaires de Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee]|[Aix-Marseille-1 Univ., 13 - Marseille (France)

    1996-12-31

    Used at its first time as an heating method in order to reach the temperature requisite for the fusion of a thermonuclear plasma, the hybrid waves has shown that they were the more efficient method for non-inductive current drive in a tokamak. The size and the objectives of a next machine such as ITER lead to the design of new antennae (in process of realisation on Tore Supra) made of oversized waveguides. This new concept of antenna will be more simple, more robust and will be able to transmit the same if not much power than the present antennae. This thesis contribute to the development of a new code called ALOHA (for `Advanced LOwer Hybrid Antenna`) which, at the end, will be able to give the characteristics and the behaviours of this new oversized antennae in front of a tokamak plasma. This thesis is also a first step in the interpretation of some experimental data concerning the measurement of coupling, absorption and current drive of the actual hybrid wave launched by a grill with rectangular waveguides. Moreover, this thesis lay some foundations of the study of these new antennae in front of a on-parallel confinement magnetic field and/or in front of poloidal inhomogeneities of plasma. (authors) 53 refs.

  20. 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...

  1. Recent studies on the welding of austenitic stainless steel piping for BWR service

    International Nuclear Information System (INIS)

    Childs, W.J.

    1986-01-01

    The incidence of intergranular stress corrosion cracking (IGSCC) in stainless steel piping in BWR power plants has led to the development of various countermeasures. Replacement of the susceptible Type 304 stainless steel with Type 316 nuclear grade stainless steel has been done by a number of plants. In order to minimize radiation exposure to welding personnel, automatic GTA welding has been used wherever possible when we make the field welds. Studies have shown that the residual stresses in the welded butt joints are affected by the welding process, weld joint design and welding procedures. A new weld joint design has been developed which minimizes the volume of deposited metal while providing adequate access for welding. It also minimizes axial and radial shrinkage and the resulting residual stresses. Other countermeasures, which have been used, include stress modifications such as induction heating stress improvement (IHSI) and last pass heat sink welding (LPHSW). It has been shown that these remedies must be process adjusted to account for the welding process employed. In some cases where UT cracking indication have been detected or where through wall cracking has occurred, weld surfacing has been used to extend life. A further approach to preventing IGSCC in the weld HAZ has been through improvement of the water chemistry by injecting hydrogen to reduce the oxygen level and by keeping the impurity level low

  2. Study of the generator/motor operation of induction machines in a high frequency link space power system

    Science.gov (United States)

    Lipo, Thomas A.; Sood, Pradeep K.

    1987-01-01

    Static power conversion systems have traditionally utilized dc current or voltage source links for converting power from one ac or dc form to another since it readily achieves the temporary energy storage required to decouple the input from the output. Such links, however, result in bulky dc capacitors and/or inductors and lead to relatively high losses in the converters due to stresses on the semiconductor switches. The feasibility of utilizing a high frequency sinusoidal voltage link to accomplish the energy storage and decoupling function is examined. In particular, a type of resonant six pulse bridge interface converter is proposed which utilizes zero voltage switching principles to minimize switching losses and uses an easy to implement technique for pulse density modulation to control the amplitude, frequency, and the waveshape of the synthesized low frequency voltage or current. Adaptation of the proposed topology for power conversion to single-phase ac and dc voltage or current outputs is shown to be straight forward. The feasibility of the proposed power circuit and control technique for both active and passive loads are verified by means of simulation and experiment.

  3. 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…

  4. 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…

  5. COOMET.EM-S8 (469/RU-a/09). International supplementary comparison of inductance standards at frequencies up to 10 MHz

    Science.gov (United States)

    2015-01-01

    This report describes the results of supplementary comparison COOMET.EM-S8 (also known as regional comparison COOMET 469/RU-a/09) of inductance standards of nominal values 0.1 μH to 100 μH, up to frequencies of 10 MHz. Six participants of the COOMET region were involved in the measurements carried out from July 2008 to October 2011. All results, but one, agreed well with the comparison reference value. This fully confirms the uncertainties declared by the participants in the CMC database on the BIPM website. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCEM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  6. A Novel Flux Estimator Based on Multiple Second-Order Generalized Integrators and Frequency-Locked Loop for Induction Motor Drives

    DEFF Research Database (Denmark)

    Zhao, Rende; Xin, Zhen; Loh, Poh Chiang

    2017-01-01

    Accurate flux estimation is essential for the implementation of a high-performance ac motor drive. However, it still faces some problems, which can better be projected by analyzing performances of existing flux estimators, implemented with either a pure integrator or a low-pass filter (LPF......). To solve the problems, an alternative flux estimator, implemented with a single second-order generalized integrator (SOGI) and a frequency-locked loop (FLL), is discussed for induction motor drives. The SOGI block included in this algorithm works for integrating the back-electromotive force, which unlike...... the pure integrator and LPF, does not experience saturation and significant dc offsets caused by different initial conditions. The single-SOGI-FLL estimator does not need additional magnitude and phase compensation, while its performance may deteriorate at low speed, caused by the inverse proportional...

  7. Silicon dioxide and low-k material sputtering in dual frequency inductive discharge by argon ions with energies from 16 to 200 eV

    Science.gov (United States)

    Lopaev, D. V.; Rakhimova, T. V.; Rakhimov, A. T.; Zotovich, A. I.; Zyryanov, S. M.; Baklanov, M. R.

    2018-01-01

    Thermal and PECVD deposited silicon dioxide and organosilicate low-k materials with porosity from 24 to 44% and corresponding k values from 2.5 to 2.0 were sputtered in dual frequency inductive discharge by argon ions with energies from 16 to 200 eV. The film thickness was measured in process by laser ellipsometry and controlled before and after plasma treatment by spectroscopic ellipsometry. Sputtering rate and yield dependencies on ion energy were measured. It was shown that SiO2 sputtering threshold in plasma is significantly lower (charging of the material surface leading to the reduction of ion energy. For low-k sputtering it is shown that the sputtering yield can be significantly higher than that of SiO2 and also  -CH3 group removal by vacuum ultraviolet photons from the discharge significantly influences material sputtering rate.

  8. Assisting Gas Optimization in CO2 Laser Welding

    DEFF Research Database (Denmark)

    Gong, Hui; Olsen, Flemming Ove

    1996-01-01

    are applied with three different flow rates for each of the gases. A number of systematic laboratory experiments is carried out by employing various experimental designs, 33 and 32 Factorial Design. In the experiments a CO2 laser is used to weld thin sheets of mild steel. The welding specimens are evaluated....... The relations between the gas parameters and signal frequencies are studied. Finally the relationships of the gas parameters and weld characteristics are studied. The possibility of using photo diode signals in controlling the gas parameters is discussed.KeywordsCO2 laser welding, assisting gas parameters...

  9. Electron backscattering for process control in electron beam welding

    International Nuclear Information System (INIS)

    Ardenne, T. von; Panzer, S.

    1983-01-01

    A number of solutions to the automation of electron beam welding is presented. On the basis of electron backscattering a complex system of process control has been developed. It allows an enlarged imaging of the material's surface, improved adjustment of the beam focusing and definite focus positioning. Furthermore, both manual and automated positioning of the electron beam before and during the welding process has become possible. Monitoring of the welding process for meeting standard welding requirements can be achieved with the aid of a control quantity derived from the results of electronic evaluation of the high-frequency electron backscattering

  10. Subminiature eddy-current transducers designed to study welded joints of titanium alloys

    Science.gov (United States)

    Malikov, V. N.; Dmitriev, S. F.; Katasonov, A. O.; Sagalakov, A. M.; Ishkov, A. V.

    2017-12-01

    Eddy current transducers (ECT) are used to construct a sensor for investigating titanium sheets connected by a welded joint. The paper provides key technical information about the eddy current transducer used and describes the procedure of measurements that makes it possible to control defects in welded joints of titanium alloys. It is capable of automatically changing the filtering cutoff frequency and operating frequency of the device. Experiments were conducted on welded VT1-0 titanium plates. The paper contains the results of these measurements. The dependence data facilitates the assessment of the quality of the welded joints and helps make an educated conclusion about welding quality.

  11. High frequency inductive measurements of organic conductors with the application of high magnetic fields and low temperatures

    Science.gov (United States)

    Winter, Laurel E.

    Organic conductors are interesting to study due to their low dimensionality that leads to a number of competing low temperature ground states. Comprised of a number of different molecules that can be varied by the substitution of one atom for another, organic systems also provide a large number of similar compounds that lend themselves to comparison studies. Two such low-dimensional organic conductors, Per2[Pt(mnt)2] and (TMTSF)2ClO4, which are members of large families of compounds, are the topic of this dissertation. Both materials are considered quasi-one-dimensional and have a number of low temperature transitions, some of which can be studied via changes in the magnetic properties of the systems. The Per2[M(mnt)2] family of compounds provides a system for exploring the similarities and differences of the system's properties when the metal M has a localized spin (M = Pt, Ni, and Fe) versus when the metal is diamagnetic (M = Au, Cu, and Co). In the case of Per2[Pt(mnt)2] - one of the compounds of focus in this dissertation - the metallic perylene chains undergo a metal- insulator transition due to the formation of a charge density wave at Tc ~ 8 K, which also occurs in Per2[Au(mnt)2] at 12 K. However, unlike in the M = Au compound, an additional transition occurs in the M = Pt compound due to the localized Pt spins (S = 1/2) on the insulating Pt(mnt)2 chains - the spin chains of Per2[Pt(mnt)2] undergo a spin-Peierls transition at 8 K. One focus of the experimental work of this dissertation focuses on the magnetic properties of the spin chains in Per2[Pt(mnt)2], via inductive susceptibility measurements at temperatures down to 0.5 K and fields up to 60 T. The experimental results show a coupling of the spin-Peierls and charge density wave states below 8 K and 20 T, above which both states are suppressed. Further measurements show a second spin state transition occurs above 20 T that coincides with a field induced insulating state in the perylene chains. These

  12. Characterisation of fume from hyperbaric welding operations

    Energy Technology Data Exchange (ETDEWEB)

    Ross, John A S; Semple, Sean [Environmental and Occupational Medicine, University of Aberdeen (United Kingdom); Duffin, Rodger [ELEGI Colt Laboratory, University of Edinburgh (United Kingdom); Kelly, Frank [Lung Biology Group, Kings College, University of London (United Kingdom); Seldmann, Joerg; Raab, Andrea, E-mail: j.a.ross@abdn.ac.u [Trace Element Speciation Laboratory, University of Aberdeen (United Kingdom)

    2009-02-01

    We report preliminary work characterising dust from hyperbaric welding trials carried out at increased pressure in a helium and oxygen atmosphere. Particle size and concentration were measured during welding. Samples for quartz and metal analysis and toxicity assessment were taken from a filter in the local fume extraction system. The residue of dust after metal extraction by nitric acid in hydrogen peroxide predominantly a non-metallic white powder assumed to be dust from welding rod coatings and thermal insulation material. Metallic analysis showed predominantly calcium, from the welding rod coating, and period 4 transition metals such as iron, manganese, magnesium and titanium (inductively coupled mass spectrometry, Agilent 7500c). The presence of zirconium indicated a contribution from grinding. The fume was nanoparticulate in nature with a mean particle diameter of 20-30 nm (MSI Inc WPS 1000XP). It showed an intermediate level of oxidative potential regarding the low-molecular weight respiratory tract lining fluid antioxidants ascorbate and glutathione and caused release of the inflammatory marker IL-8 in a human lung A 549 epithelial cell culture with no indication of cytotoxicity. The study findings have strong implications for the measurement techniques needed to assess fume exposure in hyperbaric welding and the provision of respiratory protection.

  13. A novel transient rotor current control scheme of a doubly-fed induction generator equipped with superconducting magnetic energy storage for voltage and frequency support

    Science.gov (United States)

    Shen, Yang-Wu; Ke, De-Ping; Sun, Yuan-Zhang; Daniel, Kirschen; Wang, Yi-Shen; Hu, Yuan-Chao

    2015-07-01

    A novel transient rotor current control scheme is proposed in this paper for a doubly-fed induction generator (DFIG) equipped with a superconducting magnetic energy storage (SMES) device to enhance its transient voltage and frequency support capacity during grid faults. The SMES connected to the DC-link capacitor of the DFIG is controlled to regulate the transient dc-link voltage so that the whole capacity of the grid side converter (GSC) is dedicated to injecting reactive power to the grid for the transient voltage support. However, the rotor-side converter (RSC) has different control tasks for different periods of the grid fault. Firstly, for Period I, the RSC injects the demagnetizing current to ensure the controllability of the rotor voltage. Then, since the dc stator flux degenerates rapidly in Period II, the required demagnetizing current is low in Period II and the RSC uses the spare capacity to additionally generate the reactive (priority) and active current so that the transient voltage capability is corroborated and the DFIG also positively responds to the system frequency dynamic at the earliest time. Finally, a small amount of demagnetizing current is provided after the fault clearance. Most of the RSC capacity is used to inject the active current to further support the frequency recovery of the system. Simulations are carried out on a simple power system with a wind farm. Comparisons with other commonly used control methods are performed to validate the proposed control method. Project supported by the National Natural Science Foundation of China (Grant No. 51307124) and the Major Program of the National Natural Science Foundation of China (Grant No. 51190105).

  14. Evaluation of welding performance of 20 kHz and 40 kHz ultrasonic metal welding

    Science.gov (United States)

    Kim, W. H.; Kang, E. J.; Park, D. S.

    2017-10-01

    In this study, ultrasonic horns are designed by using vibration equations, vibration modal analysis and harmonic response analysis in order to compare welding performance when ultrasonic welding is performed at resonance frequencies of 20 kHz and 40 kHz. For the weldability evaluation of the manufactured horn for 20 kHz and 40 kHz, welding strength between Ni specimens with a thickness of 0.1 mm using tensile test are compared and analyzed. The lengths of horns with resonance frequencies of 20kHz and 40kHz were calculated as 130mm and 68mm respectively. As a result of vibration modal analysis, the optimum longitudinal vibration modes of 19,584Hz and 39,794Hz are obtained in 10th mode, and the frequency response of the two horns are 19,600 Hz and 39,800 Hz respectively. As the welding conditions are changed to welding pressure 2 bar, 3 bar and 4 bar, vibration amplitude of horn 60%, 80% and 100%, tensile strengths of welded specimens are observed. The welding strength was smaller at 40 kHz than at 20 kHz even at the same amplitude. This is because diffusion action of Ni in the weld interface is facilitated at 20 kHz than at 40 kHz.

  15. Welding skate with computerized controls

    Science.gov (United States)

    Wall, W. A., Jr.

    1968-01-01

    New welding skate concept for automatic TIG welding of contoured or double-contoured parts combines lightweight welding apparatus with electrical circuitry which computes the desired torch angle and positions a torch and cold-wire guide angle manipulator.

  16. Impact testing of welded samples

    Science.gov (United States)

    Lundeen, Calvin D.

    1992-01-01

    The objective of this paper is to demonstrate how welding practice and joint design affect the performance of the joint. Also demonstrated is the importance of weld inspection to ensure quality welds.

  17. Solid State Welding Development at Marshall Space Flight Center

    Science.gov (United States)

    Ding, Robert J.; Walker, Bryant

    2012-01-01

    What is TSW and USW? TSW is a solid state weld process consisting of an induction coil heating source, a stir rod, and non-rotating containment plates Independent heating, stirring and forging controls Decouples the heating, stirring and forging process elements of FSW. USW is a solid state weld process consisting of an induction coil heating source, a stir rod, and a non-rotating containment plate; Ultrasonic energy integrated into non-rotating containment plate and stir rod; Independent heating, stirring and forging controls; Decouples the heating, stirring and forging process elements of FSW.

  18. 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...

  19. Vibration stress relief of DH 36 rectangle welded plates

    Science.gov (United States)

    Li, Shuqi; Fang, Hongyuan

    2018-03-01

    Vibration stress relief (VSR) is widely used in reducing residual stress in welded structures. However, the effectiveness of this method is still instable in some circumstance. In this study, a covert negative treatment phenomenon was investigated, i.e. natural frequency of welded structures decreased after VSR but residual stress in one direction increased. When the alteration of natural frequency after VSR is significant, the residual stresses in both the longitudinal and transversal directions shall decrease. Otherwise, residual stresses may increase on one direction. Thus, sufficient power shall be applied to the welded structures to avoid negative results.

  20. 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.

  1. Manual tube welding torch

    International Nuclear Information System (INIS)

    Kiefer, J.H.; Smith, D.J.

    1981-01-01

    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)

  2. 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.

  3. 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.

  4. Analysis of Pulsed Laser Welding Parameters Effect on Weld Geometry of 316L Stainless Steel using DOE

    Directory of Open Access Journals (Sweden)

    M. R. Pakmanesh

    2018-03-01

    Full Text Available In the present study, the optimization of pulsed Nd:YAG laser welding parameters was done on a lap-joint of a 316L stainless steel foil in order to predict the weld geometry through response surface methodology. For this purpose, the effects of laser power, pulse duration, and frequency were investigated. By presenting a second-order polynomial, the above-mentioned statistical method was managed to be well employed to evaluate the effect of welding parameters on weld width. The results showed that the weld width at the upper, middle and lower surfaces of weld cross section increases by increasing pulse durationand laser power; however, the effects of these parameters on the mentioned levels are different. The effect of pulse duration in the models of weld upper, middle and lower widths was calculated as 76, 73 and 68%, respectively. Moreover, the effect of power on theses widths was determined as 18, 24 and 28%, respectively. Finally, by superimposing these models, optimum conditions were obtained to attain a full penetration weld and the weld with no defects.

  5. Thermal kinetic inductance detector

    Science.gov (United States)

    Cecil, Thomas; Gades, Lisa; Miceli, Antonio; Quaranta, Orlando

    2016-12-20

    A microcalorimeter for radiation detection that uses superconducting kinetic inductance resonators as the thermometers. The detector is frequency-multiplexed which enables detector systems with a large number of pixels.

  6. Sintering behavior of ultra-fine Al2O3-(ZrO2 + X mol% Y2O3) ceramics by high-frequency induction heating

    International Nuclear Information System (INIS)

    Kim, S.W.; Cockcroft, S.L.; Khalil, K.A.; Ogi, K.

    2010-01-01

    Alumina-zirconia composites consisting of Al 2 O 3 -20 vol% yttria-stabilized zirconia containing two types of yttria-stabilized zirconia, 3 mol% yttria doped ZrO 2 (3YSZ) and 8 mol% yttria doped ZrO 2 (8YSZ), were consolidated very rapidly to full density by high-frequency induction heating and sintering (HFIHS). A comparison was made between the sinter behavior and the mechanical properties (hardness, fracture toughness and flexural strength) of the 3YSZ and 8YSZ material. In addition, the consolidated samples were analyzed for phase content by X-ray diffraction (XRD) and the fracture surfaces were examined using a scanning electron microscopy (SEM). The results showed that 3YSZ is most effective as a second phase for the toughening of alumina in comparison to the 8YSZ material. Al 2 O 3 -3YSZ composites exhibiting relatively good mechanical properties and limited grain growth were successfully synthesized at relatively low temperatures using this technique.

  7. Spheroidization of silica powders by radio frequency inductively coupled plasma with Ar-H2 and Ar-N2 as the sheath gases at atmospheric pressure

    Science.gov (United States)

    Li, Lin; Ni, Guo-hua; Guo, Qi-jia; Lin, Qi-fu; Zhao, Peng; Cheng, Jun-li

    2017-09-01

    Amorphous spherical silica powders were prepared by inductively coupled thermal plasma treatment at a radio frequency of 36.2 MHz. The effects of the added content of hydrogen and nitrogen into argon (serving as the sheath gas), as well as the carrier gas flow rate, on the spheroidization rate of silica powders, were investigated. The prepared silica powders before and after plasma treatment were examined by scanning electron microscopy, X-ray diffraction, and laser granulometric analysis. Results indicated that the average size of the silica particles increased, and the transformation of crystals into the amorphous state occurred after plasma treatment. Discharge image processing was employed to analyze the effect of the plasma temperature field on the spheroidization rate. The spheroidization rate of the silica powder increased with the increase of the hydrogen content in the sheath gas. On the other hand, the spheroidization rate of the silica power first increased and then decreased with the increase of the nitrogen content in the sheath gas. Moreover, the amorphous content increased with the increase of the spheroidization rate of the silica powder.

  8. High-Powered, Ultrasonically Assisted Thermal Stir Welding

    Science.gov (United States)

    Ding, Robert

    2013-01-01

    This method is a solid-state weld process capable of joining metallic alloys without melting. The weld workpieces to be joined by thermal stir welding (TSW) are drawn, by heavy forces, between containment plates past the TSW stir tool that then causes joining of the weld workpiece. TSW is similar to friction stir welding (FSW) in that material is heated into a plastic state (not melted) and stirred using a stir rod. The FSW pin tool is an integrated geometrical structure consisting of a large-diameter shoulder, and a smaller-diameter stir pin protruding from the shoulder. When the pin is plunged into a weld workpiece, the shoulder spins on the surface of the weld workpiece, thus inducing frictional heat into the part. The pin stirs the fraying surfaces of the weld joint, thus joining the weld workpiece into one structure. The shoulder and stir pin of the FSW pin tool must rotate together at a desired rotational speed. The induced frictional energy control and stir pin control of the pin tool cannot be de-coupled. The two work as one integrated unit. TSW, on the other hand, de-couples the heating and stirring of FSW, and allows for independent control of each process element. A uniquely designed induction coil heats the weld workpiece to a desired temperature, and once heated, the part moves into a stir rod whose RPM is also independently controlled. As the weld workpiece moves into the stir rod, the piece is positioned, or sandwiched, between upper and lower containment plates. The plate squeezes together, thus compressing the upper and lower surfaces of the weld workpiece. This compressive force, also called consolidation force, consolidates the plastic material within the weld nugget material as it is being stirred by the stir rod. The stir rod is positioned through the center of the top containment plate and protrudes midway through the opposite lower containment plate where it is mechanically captured. The upper and lower containment plates are separated by a

  9. Effect of stress concentration on the fatigue strength of A7N01S-T5 welded joints

    Science.gov (United States)

    Zhang, Mingyue; Gou, Guoqing; Hang, Zongqiu; Chen, Hui

    2017-07-01

    Stress concentration is a key factor that affects the fatigue strength of welded joints. In this study, the fatigue strengths of butt joints with and without the weld reinforcement were tested to quantify the effect of stress concentration. The fatigue strength of the welded joints was measured with a high-frequency fatigue machine. The P-S-N curves were drawn under different confidence levels and failure probabilities. The results show that butt joints with the weld reinforcement have much lower fatigue strength than joints without the weld reinforcement. Therefore, stress concentration introduced by the weld reinforcement should be controlled.

  10. Weld pool control in ND: YAG laser Welding

    NARCIS (Netherlands)

    Postma, S.

    2003-01-01

    During laser welding small parameter variations can result in defects and loss of quality in the weld. An important quality in Tailor Made Blanks is the weld depth. In this thesis a number of feedback control strategies are developed to control the weld depth on-line.

  11. Optimization of weld overlay dimensions for butt-welded pipes

    Energy Technology Data Exchange (ETDEWEB)

    Chintapalli, A.; Ku, F.H.; Miessi, G.A., E-mail: achintapalli@structint.com, E-mail: fku@structint.com, E-mail: amiessi@structint.com [Structural Integrity Associates, Inc., San Jose, California (United States); Yee, R.K., E-mail: Raymond.Yee@sjsu.edu [San Jose State Univ., San Jose, California (United States)

    2008-07-01

    Weld overlay technique can be used on a welded pipe with a flaw in the butt weld to prevent it from cracking further. Due to the application of weld overlay on top of the weld, compressive stresses are developed in the pipe wall and the weld. These stresses counteract the effect of the residual stresses from the butt weld and tensile stresses produced in the pipe during normal operation. Existing guidelines in the nuclear industry specify minimum dimensions (length and thickness) of the weld overlay. However, there is no guideline regarding the optimum repair dimensions that should be used to obtain minimum residual stresses induced by the weld overlay technique. The optimum dimensions in this study refer to the minimum material that can be used for the weld overlay. This results in reduced cost, time and exposure to radiation. Hence a size sensitivity study is performed by varying three parameters, the width and thickness of the weld overlay, and the size of the pipe being repaired. The repaired pipe is assumed to be subjected to typical pressurizer water reactor (PWR) operating conditions. The weld overlay process is simulated using an axisymmetric finite element model. The axial and hoop stresses in the region of the butt weld after the weld overlay are compared. The results from this study will be analyzed to establish optimum dimensions of the weld overlay for various pipe sizes to mitigate axial and circumferential crack initiation at the butt weld. (author)

  12. Explosion metal welding

    International Nuclear Information System (INIS)

    Popoff, A.A.

    1976-01-01

    Process parameters pertaining to welding similar and dissimilar metals using explosives are reviewed. The discussion centers on the interrelationship of physical parameters which play a part in achieving desirable metallurgical results. Present activities in explosion metal welding at LASL are presented and shown how they related to the interests of the ERDA community

  13. 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.

  14. Advanced Welding Torch

    Science.gov (United States)

    1996-01-01

    In order to more easily join the huge sections of the Space Shuttle external tank, Marshall Space Flight Center initiated development of the existing concept of Variable Polarity Plasma Arc (VPPA) welding. VPPA welding employs a variable current waveform that allows the system to operate for preset time increments in either of two polarity modes for effective joining of light alloys.

  15. DC arc weld starter

    Science.gov (United States)

    Campiotti, Richard H.; Hopwood, James E.

    1990-01-01

    A system for starting an arc for welding uses three DC power supplies, a high voltage supply for initiating the arc, an intermediate voltage supply for sustaining the arc, and a low voltage welding supply directly connected across the gap after the high voltage supply is disconnected.

  16. Laser Beam Oscillation Strategies for Fillet Welds in Lap Joints

    Science.gov (United States)

    Müller, Alexander; Goecke, Sven-F.; Sievi, Pravin; Albert, Florian; Rethmeier, Michael

    Laser beam oscillation opens up new possibilities of influencing the welding process in terms of compensation of tolerances and reduction of process emissions that occur in industrial applications, such as in body-in-white manufacturing. The approaches are to adapt the melt pool width in order to generate sufficient melt volume or to influence melt pool dynamics, e.g. for a better degassing. Welding results are highly dependent on the natural frequency of the melt pool, the used spot diameter and the oscillation speed of the laser beam. The conducted investigations with an oscillated 300 μm laser spot show that oscillation strategies, which are adjusted to the joining situation improve welding result for zero-gap welding as well as for bridging gaps to approximately 0.8 mm. However, a complex set of parameters has to be considered in order to generate proper welding results. This work puts emphasize on introducing them.

  17. Immunotoxicology of arc welding fume: Worker and experimental animal studies

    Science.gov (United States)

    Zeidler-Erdely, Patti C.; Erdely, Aaron; Antonini, James M.

    2015-01-01

    Arc welding processes generate complex aerosols composed of potentially hazardous metal fumes and gases. Millions of workers worldwide are exposed to welding aerosols daily. A health effect of welding that is of concern to the occupational health community is the development of immune system dysfunction. Increased severity, frequency, and duration of upper and lower respiratory tract infections have been reported among welders. Specifically, multiple studies have observed an excess mortality from pneumonia in welders and workers exposed to metal fumes. Although several welder cohort and experimental animal studies investigating the adverse effects of welding fume exposure on immune function have been performed, the potential mechanisms responsible for these effects are limited. The objective of this report was to review both human and animal studies that have examined the effect of welding fume pulmonary exposure on local and systemic immune responses. PMID:22734811

  18. Immunotoxicology of arc welding fume: worker and experimental animal studies.

    Science.gov (United States)

    Zeidler-Erdely, Patti C; Erdely, Aaron; Antonini, James M

    2012-01-01

    Arc welding processes generate complex aerosols composed of potentially hazardous metal fumes and gases. Millions of workers worldwide are exposed to welding aerosols daily. A health effect of welding that is of concern to the occupational health community is the development of immune system dysfunction. Increased severity, frequency, and duration of upper and lower respiratory tract infections have been reported among welders. Specifically, multiple studies have observed an excess mortality from pneumonia in welders and workers exposed to metal fumes. Although several welder cohort and experimental animal studies investigating the adverse effects of welding fume exposure on immune function have been performed, the potential mechanisms responsible for these effects are limited. The objective of this report was to review both human and animal studies that have examined the effect of welding fume pulmonary exposure on local and systemic immune responses.

  19. Vacuum Gas Tungsten Arc Welding

    Science.gov (United States)

    Weeks, J. L.; Todd, D. T.; Wooten, J. R.

    1997-01-01

    A two-year program investigated vacuum gas tungsten arc welding (VGTAW) as a method to modify or improve the weldability of normally difficult-to-weld materials. After a vacuum chamber and GTAW power supply were modified, several difficult-to-weld materials were studied and key parameters developed. Finally, Incoloy 903 weld overlays were produced without microfissures.

  20. Plastic deformation and wave formation on the interface of metals welded by ultrasound-assisted explosive welding

    Science.gov (United States)

    Kuz’min, E. V.; Kuz’min, S. V.; Lysak, V. I.; Lata, A. N.

    2017-10-01

    This paper presents the influence of the effect of ultrasound on the wave formation and plastic deformation in the metals welded by ultrasound-assisted explosive welding. It has been established that the influence of high-frequency acoustic waves on the metal leads to a reduction of the dynamic yield stress, which in turn leads to changes in the properties of the surface layers of metal and in the conditions of bonding between the collided plates upon explosive welding. It has been shown that the changes in the length and amplitude of waves that arise in the weld joint upon the explosive welding with the simultaneous action of ultrasonic vibrations is connected with a decrease in the magnitude of the deforming pulse and time of action of the compressive stresses that exceed the dynamic yield stress behind the point of contact.

  1. Renovating the excitation circuit of a conventional welding converter

    Indian Academy of Sciences (India)

    This paper presents two different new excitation current supplies based on power electronics for an existing conventional welding converter. The proposed circuits are simulated using Lab-VIEW 1200 AI and a PC based system. In the expressions for winding currents the dynamic inductances are used to take into account ...

  2. Calibration Fixture For Welding Robot

    Science.gov (United States)

    Holly, Krisztina J.

    1990-01-01

    Compact, lightweight device used in any position or orientation. Calibration fixture designed for use on robotic gas/tungsten-arc welding torch equipped with vision-based seam-tracking system. Through optics in hollow torch cylinder, video camera obtains image of weld, viewing along line of sight coaxial with welding electrode. Attaches to welding-torch cylinder in place of gas cup normally attached in use. By use of longer or shorter extension tube, fixture accommodates welding electrode of unusual length.

  3. 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.

  4. Investigation of mixing and diffusion processes in hybrid spot laser-MIG keyhole welding

    International Nuclear Information System (INIS)

    Zhou, J; Tsai, H L

    2009-01-01

    In hybrid laser-MIG keyhole welding, anti-crack elements can be added into the weld pool through a filler metal in anticipation of compensating mass loss, preventing porosity formation and improving compositional and mechanical properties of the welds. Understanding the mixing and diffusion of the filler metal in the molten pool is vital to achieve these desired objectives. In this study, mathematical models and associated numerical techniques have been developed to investigate the mixing and diffusion processes in hybrid laser-MIG keyhole welding. The transient interactions between droplets and weld pool and dynamics of the melt flow are studied. The effects of key process parameters, such as droplet size (wire diameter), droplet generation frequency (wire feed speed) and droplet impinging speed, on mixing/diffusion are systematically investigated. It was found that compositional homogeneity of the weld pool is determined by the competition between the mixing rate and the solidification rate. A small-size filler droplet together with high generation frequency can increase the latitudinal diffusion of the filler metal into the weld pool, while the large-size droplet along with the low generation frequency helps to get more uniform longitudinal diffusion. Increasing the impinging velocity of the filler droplet can improve the latitudinal diffusion of the filler metal. However, a high impinging velocity can cause a lower diffusion zone in the upper part of the welds. This study provides a good foundation for optimizing the hybrid laser-MIG keyhole welding process to achieve quality welds with desired properties.

  5. Diffusion welding of metals

    International Nuclear Information System (INIS)

    Susei, Shuzo; Matsui, Shigetomo; Yamada, Takeshi

    1978-01-01

    Recently, the materials with high heat resistance, corrosion resistance or strength have been developed, and some of them cannot be welded by ordinary method. Thereupon solid phase joining method is noticed, the mechanism of which is entirely different from conventional fusion welding. Among various solid phase joining methods, diffusion welding has many features. In case of joining same material, the joint can be made chemically and mechanically same as the parent material, and in case of joining different materials, joining can be made without forming any harmful compound, and the embrittlement of joints can be avoided. Kawasaki Heavy Industries Corp. has carried out a series of research on the diffusion welding of various metals, but in this paper, the characteristics of the joints of same material and different materials in titanium alloys are reported. The diffusion welding apparatus used adopts radiation heating using a tungsten heater and a hydraulic cylinder for pressing. The atmosphere of welded materials is kept in vacuum. The tested materials were industrial pure titanium TB 35 and Ti-6 Al-4 V alloy. The weldability of these materials by diffusion welding was studied, and it was confirmed that the joint efficiency of 100% was able to be obtained. However, for the practical application, more studies are required. (Kako, I.)

  6. 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...

  7. Inspection of plastic weld joints with terahertz imaging

    Science.gov (United States)

    Wietzke, S.; Krumbholz, N.; Jördens, C.; Baudrit, B.; Bastian, M.; Koch, M.

    2007-06-01

    Polymers cover the whole range from commodities to high-tech applications. Plastic products have also gained in importance for construction purposes. This draws the attention to joining techniques like welding. Common evaluation of the weld quality is mostly mechanical and destructive. Existing non-destructive techniques are mostly not entirely reliable or economically inefficient. Here, we demonstrate the potential of terahertz time-domain spectroscopy imaging as a non-destructive testing tool for the inspection of plastic weld joints. High-density polyethylene sheets welded in a lap joint with varying quality serve as samples for terahertz transmission measurements. Imperfections within the weld contact area can clearly be detected by displaying the transmitted intensity in a limited frequency range. Contaminations such as metal or sand are identified since they differ significantly from the polymer in the terahertz image. Furthermore, this new and promising technique is capable of detecting the boundaries of a weld contact area. Aside from revealing a contrast between a proper weld joint and no material connection, the size of an air gap between two plastic sheets can be determined by considering the characteristic frequency-dependent transmission through the structure: The spectral positions of the maxima and minima allow for the calculation of the air layer thickness.

  8. Dynamic Response of Wheel-Rail Interaction at Rail Weld in High-Speed Railway

    Directory of Open Access Journals (Sweden)

    Boyang An

    2017-01-01

    Full Text Available As a main part of continuously welded rail track, rail weld widely exists in high-speed railway. However, short-wave irregularities can easily initiate and develop in rail weld due to the limitation of welding technology and thus rail weld has been a main high-frequency excitation and is responsible for deterioration of track components. This work reports a 3D finite element model of wheel-rail rolling contact which can simulate dynamic wheel-rail interaction at arbitrary contact geometry up to 400 km/h. This model is employed to investigate dynamic response of wheel-rail interaction at theoretical and measured rail weld, including wheel-rail force and axle-box acceleration. These simulation results, combined with Quality Index (QI method, are used to develop a quantitative expression, which can be easily applied for evaluating rail weld deterioration based on measured rail profiles and axle-box acceleration.

  9. Nondestructive online testing method for friction stir welding using acoustic emission

    Science.gov (United States)

    Levikhina, Anastasiya

    2017-12-01

    The paper reviews the possibility of applying the method of acoustic emission for online monitoring of the friction stir welding process. It is shown that acoustic emission allows the detection of weld defects and their location in real time. The energy of an acoustic signal and the median frequency are suggested to be used as informative parameters. The method of calculating the median frequency with the use of a short time Fourier transform is applied for the identification of correlations between the defective weld structure and properties of the acoustic emission signals received during welding.

  10. 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.

  11. 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.

  12. Half bead welding technique

    International Nuclear Information System (INIS)

    Canonico, D.A.; Holz, P.P.

    1978-05-01

    The ORNL has employed the Section XI half-bead procedure for six repair welds. Table 2 identifies the repairs and the components upon which they were accomplished. The weld repairs were performed to permit us to evaluate material properties, residual stresses, weld repair procedures, and structural behavior of repaired pressure vessels. As a consequence of our study we concluded that when the half bead procedure is correctly applied: (1) there is no metallurgical degradation of the base material, (2) residual stresses of yield point magnitude will be present, and (3) the structural integrity of the pressure vessel is not impaired at Charpy V-notch upper shelf temperatures

  13. APPARATUS FOR ARC WELDING

    Science.gov (United States)

    Lingafelter, J.W.

    1960-04-01

    An apparatus is described in which a welding arc created between an annular electrode and a workpiece moves under the influence of an electromagnetic field about the electrode in a closed or annular path. This mode of welding is specially suited to the enclosing of nuclear-fuel slugs in a protective casing. For example, a uranium slug is placed in an aluminum can, and an aluminum closure is welded to the open end of the can along a closed or annular path conforming to the periphery of the end closure.

  14. Laser weld jig. [Patent application

    Science.gov (United States)

    Van Blarigan, P.; Haupt, D.L.

    1980-12-05

    A system is provided for welding a workpiece along a predetermined weld line that may be of irregular shape, which includes the step of forming a lip on the workpiece to extend parallel to the weld line, and moving the workpiece by engaging the lip between a pair of rotatable members. Rotation of one of the members at a constant speed, causes the workpiece to move so that all points on the weld line sequentially pass a fixed point in space at a constant speed, so that a laser welding beam can be directed at that fixed point to form a weld along the weld line. The workpiece can include a reusable jig forming the lip, and with the jig constructed to detachably hold parts to be welded at a position wherein the weld line of the parts extends parallel to the lip on the jig.

  15. Residual stress by repair welds

    International Nuclear Information System (INIS)

    Mochizuki, Masahito; Toyoda, Masao

    2003-01-01

    Residual stress by repair welds is computed using the thermal elastic-plastic analysis with phase-transformation effect. Coupling phenomena of temperature, microstructure, and stress-strain fields are simulated in the finite-element analysis. Weld bond of a plate butt-welded joint is gouged and then deposited by weld metal in repair process. Heat source is synchronously moved with the deposition of the finite-element as the weld deposition. Microstructure is considered by using CCT diagram and the transformation behavior in the repair weld is also simulated. The effects of initial stress, heat input, and weld length on residual stress distribution are studied from the organic results of numerical analysis. Initial residual stress before repair weld has no influence on the residual stress after repair treatment near weld metal, because the initial stress near weld metal releases due to high temperature of repair weld and then stress by repair weld regenerates. Heat input has an effect for residual stress distribution, for not its magnitude but distribution zone. Weld length should be considered reducing the magnitude of residual stress in the edge of weld bead; short bead induces high tensile residual stress. (author)

  16. Friction stir welding tool

    Science.gov (United States)

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

    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.

  17. Neutral polypropylene laser welding

    Science.gov (United States)

    Mandolfino, Chiara; Lertora, Enrico; Gambaro, Carla

    2016-10-01

    The joining of polymeric materials is a technology used in many industrial applications, from transport to telecommunications and the medical sector. A new technology for the joining of polymers is the laser welding process. In particular, fibre laser welding is a flexible technology which allows high process speed and the realization of good quality joints. Despite its application becoming more widespread in the production of assemblies of high precision, the application of laser technology for the welding of polymers has not been the subject of many studies up to now. This study focused on the welding of neutral polypropylene. The window process parameter was identified, without the use of additives to increase radiation absorption, and a mechanical characterization was conducted in order to evaluate the quality of the joints realized.

  18. Welding of refractory alloys

    International Nuclear Information System (INIS)

    Lessmann, G.G.

    1984-01-01

    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

  19. Comparative study on contribution of charge-transfer collision to excitations of iron ion between argon radio-frequency inductively-coupled plasma and nitrogen microwave induced plasma

    Energy Technology Data Exchange (ETDEWEB)

    Satoh, Kozue; Wagatsuma, Kazuaki, E-mail: wagatuma@imr.tohoku.ac.jp

    2015-06-01

    This paper describes an ionization/excitation phenomenon of singly-ionized iron occurring in an Okamoto-cavity microwave induced plasma (MIP) as well as an argon radio-frequency inductively-coupled plasma (ICP), by comparing the Boltzmann distribution among iron ionic lines (Fe II) having a wide range of the excitation energy from 4.76 to 9.01 eV. It indicated in both the plasmas that plots of Fe II lines having lower excitation energies (4.76 to 5.88 eV) were fitted on each linear relationship, implying that their excitations were caused by a dominant thermal process such as collision with energetic electron. However, Fe II lines having higher excitation energies (more than 7.55 eV) had a different behavior from each other. In the ICP, Boltzmann plots of Fe II lines assigned to the higher excited levels also followed the normal Boltzmann relationship among the low-lying excited levels, even including a deviation from it in particular excited levels having an excitation energy of ca. 7.8 eV. This deviation can be attributed to a charge-transfer collision with argon ion, which results in the overpopulation of these excited levels, but the contribution is small. On the other hand, the distribution of the high-lying excited levels was non-thermal in the Okamoto-cavity MIP, which did not follow the normal Boltzmann relationship among the low-lying excited levels. A probable reason for the non-thermal characteristics in the MIP is that a charge-transfer collision with nitrogen molecule ion having many vibrational/rotational levels could work for populating the 3d{sup 6}4p (3d{sup 5}4s4p) excited levels of iron ion broadly over an energy range of 7.6–9.0 eV, while collisional excitation by energetic electron would occur insufficiently to excite these high-energy levels. - Highlights: • This paper describes the excitation mechanism of iron ion in Okamoto-cavity MIP in comparison with conventional ICP. • Boltzmann distribution is studied among iron ionic lines of

  20. A welding technology using RobotStudio

    OpenAIRE

    Cohal Viorel

    2017-01-01

    The paper presents the results obtained in designing a welding workstation by using offline programming in RobotStudio. The developed model was used to simulate welding elements of a welded assembly. Welding routes are obtained offline. By using ArcWelding module and VirtualArc there were obtained parameters of welding technology, which are automatically in WPS.

  1. Concurrent ultrasonic weld evaluation system

    Science.gov (United States)

    Hood, Donald W.; Johnson, John A.; Smartt, Herschel B.

    1987-01-01

    A system for concurrent, non-destructive evaluation of partially completed welds for use in conjunction with an automated welder. The system utilizes real time, automated ultrasonic inspection of a welding operation as the welds are being made by providing a transducer which follows a short distance behind the welding head. Reflected ultrasonic signals are analyzed utilizing computer based digital pattern recognition techniques to discriminate between good and flawed welds on a pass by pass basis. The system also distinguishes between types of weld flaws.

  2. Half Bridge Inductive Heater

    Directory of Open Access Journals (Sweden)

    Zoltán GERMÁN-SALLÓ

    2015-12-01

    Full Text Available Induction heating performs contactless, efficient and fast heating of conductive materials, therefore became one of the preferred heating procedure in industrial, domestic and medical applications. During induction heating the high-frequency alternating currents that heat the material are induced by means of electromagnetic induction. The material to be heated is placed inside the time-varying magnetic field generated by applying a highfrequency alternating current to an induction coil. The alternating electromagnetic field induces eddy currents in the workpiece, resulting resistive losses, which then heat the material. This paper describes the design of a power electronic converter circuit for induction heating equipment and presents the obtained results. The realized circuit is a low power half bridge resonant inverter which uses power MOS transistors and adequate driver circuits.

  3. Automatic welding machine for piping

    International Nuclear Information System (INIS)

    Yoshida, Kazuhiro; Koyama, Takaichi; Iizuka, Tomio; Ito, Yoshitoshi; Takami, Katsumi.

    1978-01-01

    A remotely controlled automatic special welding machine for piping was developed. This machine is utilized for long distance pipe lines, chemical plants, thermal power generating plants and nuclear power plants effectively from the viewpoint of good quality control, reduction of labor and good controllability. The function of this welding machine is to inspect the shape and dimensions of edge preparation before welding work by the sense of touch, to detect the temperature of melt pool, inspect the bead form by the sense of touch, and check the welding state by ITV during welding work, and to grind the bead surface and inspect the weld metal by ultrasonic test automatically after welding work. The construction of this welding system, the main specification of the apparatus, the welding procedure in detail, the electrical source of this welding machine, the cooling system, the structure and handling of guide ring, the central control system and the operating characteristics are explained. The working procedure and the effect by using this welding machine, and the application to nuclear power plants and the other industrial field are outlined. The HIDIC 08 is used as the controlling computer. This welding machine is useful for welding SUS piping as well as carbon steel piping. (Nakai, Y.)

  4. METHOD OF OBTAINING AN IMPROVED WELD IN INERT ARC WELDING

    Science.gov (United States)

    Correy, T.B.

    1962-12-11

    A method is reported for inert arc welding. An a-c welding current is applied to the workpiece and welding electrode such that the positive portion of each cycle thereof, with the electrode positive, has only sufficient energy to clean the surface of the workpiece and the negative portion of each cycle thereof, with the electrode negative, contains the energy required to weld. (AEC)

  5. Labor Induction

    Science.gov (United States)

    f AQ FREQUENTLY ASKED QUESTIONS FAQ154 LABOR, DELIVERY, AND POSTPARTUM CARE Labor Induction • What is labor induction? • Why is labor induced? • What is the Bishop score? • What is “ripening ...

  6. Measurement of Dynamic Resistance in Resistance Spot Welding

    DEFF Research Database (Denmark)

    Wu, Pei; Zhang, Wenqi; Bay, Niels

    Through years, the dynamic resistance across the electrodes has been used for weld quality estimation and contact resistance measurement. However, the previous methods of determining the dynamic resistance were mostly based on measuring the voltage and current on the secondary side...... of the transformer in resistance welding machines, implying defects from induction noise and interference with the leads connected to the electrodes for measuring the voltage. In this study, the dynamic resistance is determined by measuring the voltage on the primary side and the current on the secondary side......, as another application, the proposed method is used to measure the faying surface contact resistance....

  7. Measurement of Dynamic Resistance in Resistance Spot Welding

    DEFF Research Database (Denmark)

    Wu, Pei; Lu, J.; Zhang, Wenqi

    2007-01-01

    The conventional methods of determining the dynamic resistance were mostly done by measuring the voltage and current at secondary side of transformer in resistance welding machines, in which the measuring set-up normally interferes with the movement of electrode, and the measuring precision...... is influenced by inductive noise caused by the high welding current. In this study, the dynamic resistance is determined by measuring the voltage at primary side and current at secondary side. This increases the accuracy of measurement because of higher signal-noise ratio, and allows to apply to in...

  8. Increased risk of parkinsonism associated with welding exposure.

    Science.gov (United States)

    Racette, Brad A; Criswell, Susan R; Lundin, Jessica I; Hobson, Angela; Seixas, Noah; Kotzbauer, Paul T; Evanoff, Bradley A; Perlmutter, Joel S; Zhang, Jing; Sheppard, Lianne; Checkoway, Harvey

    2012-10-01

    Manganese (Mn), an established neurotoxicant, is a common component of welding fume. The neurological phenotype associated with welding exposures has not been well described. Prior epidemiologic evidence linking occupational welding to parkinsonism is mixed, and remains controversial. This was a cross-sectional and nested case-control study to investigate the prevalence and phenotype of parkinsonism among 811 shipyard and fabrication welders recruited from trade unions. Two reference groups included 59 non-welder trade workers and 118 newly diagnosed, untreated idiopathic PD patients. Study subjects were examined by a movement disorders specialist using the Unified Parkinson Disease Rating Scale motor subsection 3 (UPDRS3). Parkinsonism cases were defined as welders with UPDRS3 score ≥15. Normal was defined as UPDRS3welding. Adjusted prevalence ratios for parkinsonism were calculated in relation to quartiles of welding years. The overall prevalence estimate of parkinsonism was 15.6% in welding exposed workers compared to 0% in the reference group. Among welders, we observed a U-shaped dose-response relation between weighted welding exposure-years and parkinsonism. UPDRS3 scores for most domains were similar between welders and newly diagnosed idiopathic Parkinson disease (PD) patients, except for greater frequency of rest tremor and asymmetry in PD patients. This work-site based study among welders demonstrates a high prevalence of parkinsonism compared to nonwelding-exposed workers and a clinical phenotype that overlaps substantially with PD. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Alternate Welding Processes for In-Service Welding

    Science.gov (United States)

    2009-04-24

    Conducting weld repairs and attaching hot tap tees onto pressurized pipes has the advantage of avoiding loss of service and revenue. However, the risks involved with in-service welding need to be managed by ensuring that welding is performed in a rep...

  10. Certification of a weld produced by friction stir welding

    Science.gov (United States)

    Obaditch, Chris; Grant, Glenn J

    2013-10-01

    Methods, devices, and systems for providing certification of friction stir welds are disclosed. A sensor is used to collect information related to a friction stir weld. Data from the sensor is compared to threshold values provided by an extrinsic standard setting organizations using a certification engine. The certification engine subsequently produces a report on the certification status of the weld.

  11. Ultrasonic inspection of austenitic welds

    International Nuclear Information System (INIS)

    Baikie, B.L.; Wagg, A.R.; Whittle, M.J.; Yapp, D.

    1976-01-01

    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

  12. Induction cooking

    Energy Technology Data Exchange (ETDEWEB)

    Grosbety, Y. [Ugine Aciers, 73 (France)

    1994-10-01

    The principles of heating by electromagnetic induction, the large families of induction hobs and key figures of the rapidity developing market. Performances and interests of induction (energy savings, rapidity and precision of heating, safety). Steels used: ferritic stainless steels alone or three-layer materials. (author). 4 refs., 8 figs., 2 tabs.

  13. Resistance Spot Welding of dissimilar Steels

    Directory of Open Access Journals (Sweden)

    Ladislav Kolařík

    2012-01-01

    Full Text Available This paper presents an analysis of the properties of resistance spot welds between low carbon steel and austenitic CrNi stainless steel. The thickness of the welded dissimilar materials was 2 mm. A DeltaSpot welding gun with a process tape was used for welding the dissimilar steels. Resistance spot welds were produced with various welding parameters (welding currents ranging from 7 to 8 kA. Light microscopy, microhardness measurements across the welded joints, and EDX analysis were used to evaluate the quality of the resistance spot welds. The results confirm the applicability of DeltaSpot welding for this combination of materials.

  14. Induction linacs

    International Nuclear Information System (INIS)

    Keefe, D.

    1986-07-01

    The principle of linear induction acceleration is described, and examples are given of practical configurations for induction linacs. These examples include the Advanced Technology Accelerator, Long Pulse Induction Linac, Radial Line Accelerator (RADLAC), and Magnetically-Insulated Electron-Focussed Ion Linac. A related concept, the auto accelerator, is described in which the high-current electron-beam technology in the sub-10 MeV region is exploited to produce electron beams at energies perhaps as high as the 100 to 1000 MeV range. Induction linacs for ions are also discussed. The efficiency of induction linear acceleration is analyzed

  15. Robotic Welding and Inspection System

    Energy Technology Data Exchange (ETDEWEB)

    H. B. Smartt; D. P. Pace; E. D. Larsen; T. R. McJunkin; C. I. Nichol; D. E. Clark; K. L. Skinner; M. L. Clark; T. G. Kaser; C. R. Tolle

    2008-06-01

    This paper presents a robotic system for GTA welding of lids on cylindrical vessels. The system consists of an articulated robot arm, a rotating positioner, end effectors for welding, grinding, ultrasonic and eddy current inspection. Features include weld viewing cameras, modular software, and text-based procedural files for process and motion trajectories.

  16. 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…

  17. 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)…

  18. Thermal and dynamic effects in electron beam welding cavities

    Energy Technology Data Exchange (ETDEWEB)

    Schauer, D.A.

    1977-08-01

    An experimental and analytical study of the temperature distributions along the molten metal surface in an electron beam welding cavity is described. Surface temperature distributions in cavities were measured with a narrow band infrared radiation pyrometer. The availability of the cavity temperature measurements allowed estimates to be made for the vapor pressure and surface energy forces as a function of cavity position. The results indicated a force imbalance occurred in the cavity. It is postulated that at the location of the force imbalance a liquid material projection forms periodically and moves into the path of the electron beam. The liquid in this projection is driven towards the bottom, partially filling the cavity. This action is followed by the electron beam pushing the liquid aside to form a maximum depth cavity. This process is then repeated. An analysis for predicting cavity oscillation frequency shows reasonable agreement with frequencies measured at the weld root determined from weld sections. A study of the measured temperature distributions in cavities of varying depth combined with the force imbalance observations led to an interpretation of when spiking might occur. A procedure is proposed for determining the spiking tendency for a given set of weld parameters. The results of this study permit a designer to select apriori the best set of weld parameters to achieve a weld of predictable quality.

  19. Thermal and dynamic effects in electron beam welding cavities

    International Nuclear Information System (INIS)

    Schauer, D.A.

    1977-08-01

    An experimental and analytical study of the temperature distributions along the molten metal surface in an electron beam welding cavity is described. Surface temperature distributions in cavities were measured with a narrow band infrared radiation pyrometer. The availability of the cavity temperature measurements allowed estimates to be made for the vapor pressure and surface energy forces as a function of cavity position. The results indicated a force imbalance occurred in the cavity. It is postulated that at the location of the force imbalance a liquid material projection forms periodically and moves into the path of the electron beam. The liquid in this projection is driven towards the bottom, partially filling the cavity. This action is followed by the electron beam pushing the liquid aside to form a maximum depth cavity. This process is then repeated. An analysis for predicting cavity oscillation frequency shows reasonable agreement with frequencies measured at the weld root determined from weld sections. A study of the measured temperature distributions in cavities of varying depth combined with the force imbalance observations led to an interpretation of when spiking might occur. A procedure is proposed for determining the spiking tendency for a given set of weld parameters. The results of this study permit a designer to select apriori the best set of weld parameters to achieve a weld of predictable quality

  20. Laser welding parameters for manufacturing iridium-192 (Ir-192) source

    International Nuclear Information System (INIS)

    Anung Pujiyanto; Moch Subechi; Hotman Lubis; Diandono KY

    2013-01-01

    Number of cervical cancer patients in Indonesia is growing every year. One of cervical cancer treatment was fairly effective use brachytherapy treatment with radioisotope sources of iridium-192. Manufacturing of iridium sources for brachytherapy can be done by incorporating the iridium-192 into stainless steel microcapsules then welding using laser welder which the quality of the welding of iridium source (Ir-192) was determined by the welding parameters such as full power, energy frequency, average power and speed. Based on the result of leakage test using pressure -20 inch Hg and tensile test 2.5 bar showed the welding parameters III and IV did not have leakage and damaged. So that parameters III and IV are recommended to be applied to Ir-192 HDR's source. (author)

  1. Ultrasonic Evaluation of Weld Strength for Aluminum Ultrasonic Spot Welds

    Science.gov (United States)

    Ghaffari, Bita; Hetrick, Elizabeth T.; Mozurkewich, George; Reatherford, Larry V.

    2005-04-01

    The goal of this work is to determine the feasibility of using an ultrasonic, non-destructive technique for post-process evaluation of aluminum ultrasonic spot welds. A focused immersion transducer was utilized to obtain a C-scan of the weld interface, from which a weighted ultrasonic contact area was estimated. Weldments were subsequently tested destructively to determine the weld strength. The square root of the weld contact area displayed a relatively good correlation with weld strength, r2=0.85.

  2. 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.

  3. Milestones in welding technology

    Science.gov (United States)

    Dolby, Richard E.

    2013-09-01

    Sir Alan's PhD thesis describes his research into cracking during arc welding of armour steels. Throughout his career, he had a strong interest in defects of all types, how they formed in metallic structures and how the larger ones could be detected and sized by non-destructive techniques. He was also vitally concerned with how defects impacted on the engineering integrity of welded structures, particularly the risk of fracture in nuclear plant. This study presents a view of some of the major milestones in global welding technology that took place over the 60 or more years of Sir Alan's career and highlights those where he had a personal and direct involvement.

  4. Influence of Main Characteristic Features of Spot Welding on Welded Connection/Joint Strength

    Science.gov (United States)

    Al Quran, Firas M. F.; Matarneh, M. I.; Belik, A. G.

    2014-03-01

    To provide the required quality of welded connection in spot welding, an investigation of the influence of characteristic features of welding conditions on the welded connection strength and choice of the best process parameters are carried out.

  5. Combining Welding Expert Systems With Welding Databases to Improve Shipbuilding Production (The National Shipbuilding Research Program)

    National Research Council Canada - National Science Library

    Vandetverldt, Hans H; Johnston, Sterling; Jones, Jerald E; White, Dawn; Cleveland, B

    1989-01-01

    .... The WELDEXCELL system is a WELDing EXpert manufacturing CELL that provides computerized technical support information, off-line weld planning, and an integrated welding robot/welding system/vision system controller...

  6. Comparison of Welding Residual Stresses of Hybrid Laser-Arc Welding and Submerged Arc Welding in Offshore Steel Structures

    DEFF Research Database (Denmark)

    Andreassen, Michael Joachim; Yu, Zhenzhen; Liu, Stephen

    2016-01-01

    In the offshore industry, welding-induced distortion and tensile residual stresses have become a major concern in relation to the structural integrity of a welded structure. Particularly, the continuous increase in size of welded plates and joints needs special attention concerning welding induced...... are hybrid laser-arc welding (HLAW) and submerged arc welding (SAW). Both welding methods are applied for a full penetration butt-weld of 10 mm thick plates made of thermomechanically hot-rolled, low-carbon, fine-grain S355ML grade steel used in offshore steel structures. The welding residual stress state...

  7. Spot Welding of Honeycomb Structures

    Science.gov (United States)

    Cohal, V.

    2017-08-01

    Honeycomb structures are used to prepare meals water jet cutting machines for textile. These honeycomb structures are made of stainless steel sheet thickness of 0.1-0.2 mm. Corrugated sheet metal strips are between two gears with special tooth profile. Hexagonal cells for obtaining these strips are welded points between them. Spot welding device is three electrodes in the upper part, which carries three welding points across the width of the strip of corrugated sheet metal. Spot welding device filled with press and advance mechanisms. The paper presents the values of the regime for spot welding.

  8. Ternary gas plasma welding torch

    Science.gov (United States)

    Rybicki, Daniel J. (Inventor); Mcgee, William F. (Inventor); Waldron, Douglas J. (Inventor)

    1995-01-01

    A plasma arc welding torch is discussed. A first plasma gas is directed through the body of the welding torch and out of the body across the tip of a welding electrode disposed at the forward end of the body. A second plasma gas is disposed for flow through a longitudinal bore in the electrode. The second plasma gas enters one end of the electrode and exits the electrode at the tip thereof for co-acting with the electric welding arc to produce the desired weld. A shield gas is directed through the torch body and circulates around the head of the torch adjacent to the electrode tip.

  9. Mechanized hyperbaric welding by robots

    International Nuclear Information System (INIS)

    Aust, E.; Santos, J.F. dos; Bohm, K.H.; Hensel, H.D.

    1988-01-01

    At the GKSS-Forschungszentrum investigations are carried out on mechanized welded test plates produced under working pressure between 10 to 110 bar in breathable TRIMIX-5-atmosphere. The welds are performed by a modified industrial robot, which was adapted in its components to withstand these severe conditions. Variations on the welding parameters were made to maintain a stable arc as well as to provide on indication of the effect of the variables on the mechanical properties of the welded joint. During all tests the robot showed a very good function. Good reliable welds were achieved meeting the requirements according API II04 or BS 4515-1984. (orig.) [de

  10. The pipes for gas and oil pipelines mains one-sided high-speed welding

    Directory of Open Access Journals (Sweden)

    Сергій Вікторович Щетинін

    2016-11-01

    Full Text Available Electromagnetic theory of the undercuts formation under the arc magnetic field action according to which as welding speed increases cooling intensifies and arc diameter reduces, induction and magnetic pressure increase, pinch-effect amplifies, has been proved. The arc concentrates, heat input and the pool side edges electrical resistance reduce with the result that current through the side walls and a downward electromagnetic force, under the action of which the liquid metal flows from the pool edges, increase and the undercuts form. In high-speed welding a composite electrode as compared with the wire electrode the heat input into the side edges and their electrical resistance increase; current and induction at the pool side edges and the electromagnetic force decrease that providing the seams qualitative formation and confirming the electromagnetic theory of the undercuts. With welding speed increasing the weld pool molten metal crystallization rate increases in proportion to it, microstructure gets reduced and welding stresses decrease, that providing the welds joints toughness rise. By increasing welding speed due to deflection rearward the arc pressure decreases, the molten metal movement rate into the back part of the pool grows, that resulting in the molten metal hydrodynamic pressure reduction. Due to simultaneous reduction of the arc pressure, of the downward electromagnetic force and of the molten metal hydrodynamic pressure, the crystallization rate increase and the pool molten state time reduction the backing bead formation on the melt backing improves greatly at the high-speed welding. The energy-saving process of one-sided high-speed welding of the pipes for gas and oil pipelines on the melt backing with the use of glass flux by means of a composite electrode, which provides quality and the welded joints toughness increase, has been developed

  11. Understanding Friction Stir Welding

    Science.gov (United States)

    Nunes, A. C., Jr.

    2018-01-01

    This Technical Memorandum explains the friction stir welding process in terms of two basic concepts: the concentration of deformation in a shear surface enveloping the tool and the composition of the overall plastic flow field around the tool from simple flow field components. It is demonstrated how weld structure may be understood and torque, drag, and lateral tool forces may be estimated using these concepts. Some discrepancies between computations and accompanying empirical data are discussed in the text. This work is intended to be helpful to engineers in diagnosing problems and advancing technology.

  12. 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...

  13. Induction motor control

    Science.gov (United States)

    Hansen, Irving G.

    1990-01-01

    Electromechanical actuators developed to date have commonly ultilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilized induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high-frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high-frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  14. Induction motor control

    Science.gov (United States)

    Hansen, Irving G.

    1990-01-01

    Electromechanical actuators developed to date have commonly utilized permanent magnet (PM) synchronous motors. More recently switched reluctance (SR) motors have been advocated due to their robust characteristics. Implications of work which utilizes induction motors and advanced control techniques are discussed. When induction motors are operated from an energy source capable of controlling voltages and frequencies independently, drive characteristics are obtained which are superior to either PM or SR motors. By synthesizing the machine frequency from a high frequency carrier (nominally 20 kHz), high efficiencies, low distortion, and rapid torque response are available. At this time multiple horsepower machine drives were demonstrated, and work is on-going to develop a 20 hp average, 40 hp peak class of aerospace actuators. This effort is based upon high frequency power distribution and management techniques developed by NASA for Space Station Freedom.

  15. Welding method by remote handling

    International Nuclear Information System (INIS)

    Hashinokuchi, Minoru.

    1994-01-01

    Water is charged into a pit (or a water reservoir) and an article to be welded is placed on a support in the pit by remote handling. A steel plate is disposed so as to cover the article to be welded by remote handling. The welding device is positioned to the portion to be welded and fixed in a state where the article to be welded is shielded from radiation by water and the steel plate. Water in the pit is drained till the portion to be welded is exposed to the atmosphere. Then, welding is conducted. After completion of the welding, water is charged again to the pit and the welding device and fixing jigs are decomposed in a state where the article to be welded is shielded again from radiation by water and the steel plate. Subsequently, the steel plate is removed by remote handling. Then, the article to be welded is returned from the pit to a temporary placing pool by remote handling. This can reduce operator's exposure. Further, since the amount of the shielding materials can be minimized, the amount of radioactive wastes can be decreased. (I.N.)

  16. Inertia and friction welding of aluminum alloy 1100 to type 316 stainless steel

    International Nuclear Information System (INIS)

    Perkins, M.A.

    1979-01-01

    The inertia and friction-welding processes were evaluated for joining aluminum alloy 1100-H14 and Type 316 vacuum-induction melted, vacuum-arc remelted (VIM VAR) stainless steel. While both processes consistently produced joints in which the strength exceeded the strength of the aluminum base metal, 100 percent bonding was not reliably achieved with inertia welding. The deficiency points out the need for development of nondestructive testing techniques for this type of joint. Additionally, solid-state volume diffusion did not appear to be a satisfactory explanation for the inertia and friction-welding bonding mechanism

  17. Visualization of Spot- welding Resistance

    Directory of Open Access Journals (Sweden)

    Michal Černý

    2016-01-01

    Full Text Available This contribution devotes to monitoring of processes running during joining of steel sheets by incadescent so called point welding using non-destructive trial method – acoustic emission (AE. The joining process is detailed described within experimental measuring from the point of view of metallurgic effects runnig during weld creation (records obtained by means of AE method. It takes into consideration quality of joined steels within welding data of steel producer. Steel welding (determined by chemical composition during mechanical verification and firmness of welds consider results of measurement AE and fracture effect of point joints. The measurement also demonstrates conclusion about connection of metallurgic processes with material wave effects (AE measurement and their impact on firmness of joint at steel with guaranteed welding, difficult welding and at their potential combination.

  18. Induction heating using induction coils in series-parallel circuits

    Science.gov (United States)

    Matsen, Marc Rollo; Geren, William Preston; Miller, Robert James; Negley, Mark Alan; Dykstra, William Chet

    2017-11-14

    A part is inductively heated by multiple, self-regulating induction coil circuits having susceptors, coupled together in parallel and in series with an AC power supply. Each of the circuits includes a tuning capacitor that tunes the circuit to resonate at the frequency of AC power supply.

  19. 49 CFR 195.228 - Welds and welding inspection: Standards of acceptability.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welds and welding inspection: Standards of... SAFETY TRANSPORTATION OF HAZARDOUS LIQUIDS BY PIPELINE Construction § 195.228 Welds and welding inspection: Standards of acceptability. (a) Each weld and welding must be inspected to insure compliance with...

  20. Inductive reasoning.

    Science.gov (United States)

    Hayes, Brett K; Heit, Evan; Swendsen, Haruka

    2010-03-01

    Inductive reasoning entails using existing knowledge or observations to make predictions about novel cases. We review recent findings in research on category-based induction as well as theoretical models of these results, including similarity-based models, connectionist networks, an account based on relevance theory, Bayesian models, and other mathematical models. A number of touchstone empirical phenomena that involve taxonomic similarity are described. We also examine phenomena involving more complex background knowledge about premises and conclusions of inductive arguments and the properties referenced. Earlier models are shown to give a good account of similarity-based phenomena but not knowledge-based phenomena. Recent models that aim to account for both similarity-based and knowledge-based phenomena are reviewed and evaluated. Among the most important new directions in induction research are a focus on induction with uncertain premise categories, the modeling of the relationship between inductive and deductive reasoning, and examination of the neural substrates of induction. A common theme in both the well-established and emerging lines of induction research is the need to develop well-articulated and empirically testable formal models of induction. Copyright © 2010 John Wiley & Sons, Ltd. For further resources related to this article, please visit the WIREs website. Copyright © 2010 John Wiley & Sons, Ltd.

  1. Method for welding chromium molybdenum steels

    Science.gov (United States)

    Sikka, Vinod K.

    1986-01-01

    Chromium-molybdenum steels exhibit a weakening after welding in an area adjacent to the weld. This invention is an improved method for welding to eliminate the weakness by subjecting normalized steel to a partial temper prior to welding and subsequently fully tempering the welded article for optimum strength and ductility.

  2. 49 CFR 192.225 - Welding procedures.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding procedures. 192.225 Section 192.225... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192.225 Welding procedures. (a) Welding must be performed by a qualified welder in accordance with welding procedures...

  3. Tool For Robotic Resistive Roll Welding

    Science.gov (United States)

    Gilber, Jeffrey L.

    1991-01-01

    Roll-welding attachment for robot simple, inexpensive device incorporating modified commercial resistance-welding gun. Modified welding gun easily attaches to end effector of robot. Robot applies welding force and moves electrode wheel along prescribed path. Resistance-welding current starts and stops automatically according to force exerted against workpiece. Used to apply brazing foil to workpiece.

  4. Sensor integration for robotic laser welding processes

    NARCIS (Netherlands)

    Iakovou, D.; Aarts, Ronald G.K.M.; Meijer, J.; Ostendorf, A; Hoult, A.; Lu, Y.

    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,

  5. Integrated sensors for robotic laser welding

    NARCIS (Netherlands)

    Iakovou, D.; Aarts, Ronald 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

  6. Development of Temper Bead Welding Process for Weld Overlay of Dissimilar Welds

    Energy Technology Data Exchange (ETDEWEB)

    Byeon, J. G.; Park, K. S.; Kim, Y. J. [Doosan Heavy Industries and Construction Co., Ltd., Seoul (Korea, Republic of)

    2008-10-15

    In recent years, the dissimilar weld metal used to connect stainless steel piping and low alloy steel or carbon steel components have experienced cracking in nuclear reactor piping systems. The cracking has been observed in several Pressurized Water Reactors in overseas. In Several cases, the cracking was repaired using structural weld overlays, a repair technique that has been in use in the U.S. in Boiling Water Reactors for over twenty years. Although weld overlays have been used primarily as a repair for flawed piping, they can also be applied at locations that have not yet exhibited any cracking, but are considered susceptible to cracking. The purpose of this research is to develop the temper bead weld process for the weld overlay of the dissimilar weld pipe. We developed equipment for the overlay system, applied Procedure Qualification(PQ) for the temper bead welding process.

  7. 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…

  8. Welding in nuclear engineering

    International Nuclear Information System (INIS)

    1982-01-01

    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) [de

  9. Numerical simulation of welding

    DEFF Research Database (Denmark)

    Hansen, Jan Langkjær; Thorborg, Jesper

    Aim of project:To analyse and model the transient thermal field from arc welding (SMAW, V-shaped buttweld in 15mm plate) and to some extend the mechanical response due to the thermal field. - To implement this model in a general purpose finite element program such as ABAQUS.The simulation...

  10. Corrosion Resistant Cladding by YAG Laser Welding in Underwater Environment

    International Nuclear Information System (INIS)

    Tsutomi Kochi; Toshio Kojima; Suemi Hirata; Ichiro Morita; Katsura Ohwaki

    2002-01-01

    It is known that stress-corrosion cracking (SCC) will occur in nickel-base alloys used in Reactor Pressure Vessel (RPV) and Internals of nuclear power plants. A SCC sensitivity has been evaluated by IHI in each part of RPV and Internals. There are several water level instrumentation nozzles installed in domestic BWR RPV. In water level instrumentation nozzles, 182 type nickel-base alloys were used for the welding joint to RPV. It is estimated the SCC potential is high in this joint because of a higher residual stress than the yield strength (about 400 MPa). This report will describe a preventive maintenance method to these nozzles Heat Affected Zone (HAZ) and welds by a corrosion resistant cladding (CRC) by YAG Laser in underwater environment (without draining a reactor water). There are many kinds of countermeasures for SCC, for example, Induction Heating Stress Improvement (IHSI), Mechanical Stress Improvement Process (MSIP) and so on. A YAG laser CRC is one of them. In this technology a laser beam is used for heat source and irradiated through an optical fiber to a base metal and SCC resistant material is used for welding wires. After cladding the HAZ and welds are coated by the corrosion resistant materials so their surfaces are improved. A CRC by gas tungsten arc welding (GTAW) in an air environment had been developed and already applied to a couple of operating plants (16 Nozzles). This method was of course good but it spent much time to perform because of an installation of some water-proof working boxes to make a TIG-weldability environment. CRC by YAG laser welding in underwater environment has superior features comparing to this conventional TIG method as follows. At the viewpoint of underwater environment, (1) an outage term reduction (no drainage water). (2) a radioactive exposure dose reduction for personnel. At that of YAG laser welding, (1) A narrower HAZ. (2) A smaller distortion. (3) A few cladding layers. A YAG laser CRC test in underwater

  11. Acoustic emission monitoring during welding

    International Nuclear Information System (INIS)

    Prine, D.W.

    1980-01-01

    Weld repair is a major cost item, particularly in the fabrication of heavy section weldments such as pressure vessels. A heavy section repair can frequently leave the weld with worse problems than the original flaw. These problems may include damage to weld microstructure as well as added residual stress. The removal of flaws through in-process repair can minimize these problems and certainly, the removal of one or two passes and their replacement with automatic welding procedure is considerably cheaper than a heavy section post weld repair. The major barrier to application of in-process repair is the lack of an effective in-process inspection procedure. In-process monitoring of Acoustic Emission shows great promise for providing this much needed tool. The successful application of acoustic emission to in-process weld monitoring requires that advanced signal processing and pattern recognition techniques be applied if the flaw related acoustic emission is to be separated from the overwhelming amount of background noise present in welding. GARD, INC. has studied the problem of applying in-process acoustic emission monitoring to weld inspection for over 9 years and has empirically developed AE signal processing techniques which allow typical weld flaws to be detected, located, and characterized. This paper discusses these techniques and describes a recent successful field test of a microcomputer based AE weld monitor in a nuclear fabrication plant. (author)

  12. Galvanic corrosion of beryllium welds

    International Nuclear Information System (INIS)

    Hill, M.A.; Butt, D.P.; Lillard, R.S.

    1997-01-01

    Beryllium is difficult to weld because it is highly susceptible to cracking. The most commonly used filler metal in beryllium welds is Al-12 wt.% Si. Beryllium has been successfully welded using Al-Si filler metal with more than 30 wt.% Al. This filler creates an aluminum-rich fusion zone with a low melting point that tends to backfill cracks. Drawbacks to adding a filler metal include a reduction in service temperature, a lowering of the tensile strength of the weld, and the possibility for galvanic corrosion to occur at the weld. To evaluate the degree of interaction between Be and Al-Si in an actual weld, sections from a mock beryllium weldment were exposed to 0.1 M Cl - solution. Results indicate that the galvanic couple between Be and the Al-Si weld material results in the cathodic protection of the weld and of the anodic dissolution of the bulk Be material. While the cathodic protection of Al is generally inefficient, the high anodic dissolution rate of the bulk Be during pitting corrosion combined with the insulating properties of the Be oxide afford some protection of the Al-Si weld material. Although dissolution of the Be precipitate in the weld material does occur, no corrosion of the Al-Si matrix was observed

  13. Improvements in and relating to welding

    International Nuclear Information System (INIS)

    Taylor, B.D.

    1979-01-01

    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.)

  14. Horizontal electron beam welding for stainless steels

    International Nuclear Information System (INIS)

    Martin, P.; Olivera, J.J.

    1977-01-01

    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 [fr

  15. In-field Welding and Coating Protocols

    Science.gov (United States)

    2009-05-12

    Gas Technology Institute (GTI) and Edison Welding Institute (EWI) created both laboratory and infield girth weld samples to evaluate the effects of weld geometry and hydrogen off-gassing on the performance of protective coatings. Laboratory made plat...

  16. Welding residual stress distributions for dissimilar metal nozzle butt welds in pressurized water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Soo; Kim, Ju Hee; Bae, Hong Yeol; OH, Chang Young; Kim, Yun Jae [Korea Univ., Seoul (Korea, Republic of); Lee, Kyungsoo [Korea Electric Power Research Institute, Daejeon (Korea, Republic of); Song, Tae Kwang [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2012-02-15

    In pressurized water nuclear reactors, dissimilar metal welds are susceptible to primary water stress corrosion cracking. To access this problem, accurate estimation of welding residual stresses is important. This paper provides general welding residual stress profiles in dissimilar metal nozzle butt welds using finite element analysis. By introducing a simplified shape for dissimilar metal nozzle butt welds, changes in the welding residual stress distribution can be seen using a geometry variable. Based on the results, a welding residual stress profile for dissimilar metal nozzle butt welds is proposed that modifies the existing welding residual stress profile for austenitic pipe butt welds.

  17. Developments in welding and joining methods of metallic materials

    International Nuclear Information System (INIS)

    Pilarczyk, J.

    2007-01-01

    The impact of the welding technology on the economy development. The welding and joining methods review. The particular role of the laser welding and its interesting applications: with filler metal, twin spot laser welding, hybrid welding process, remote welding. The fiber lasers. The high intensity electron beams applications for surface modification. The TIG welding with the use of the active flux. Friction welding, friction stir welding and friction linear welding. (author)

  18. Factors affecting weld root morphology in laser keyhole welding

    Science.gov (United States)

    Frostevarg, Jan

    2018-02-01

    Welding production efficiency is usually optimised if full penetration can be achieved in a single pass. Techniques such as electron and laser beam welding offer deep high speed keyhole welding, especially since multi-kilowatt lasers became available. However, there are limitations for these techniques when considering weld imperfections such as weld cap undercuts, interior porosity or humps at the root. The thickness of sheets during full penetration welding is practically limited by these root humps. The mechanisms behind root morphology formation are not yet satisfactory understood. In this paper root humping is studied by reviewing previous studies and findings and also by sample examination and process observation by high speed imaging. Different process regimes governing root quality are presented, categorized and explained. Even though this study mainly covers laser beam and laser arc hybrid welding, the presented findings can generally be applied full penetration welding in medium to thick sheets, especially the discussion of surface tension effects. As a final result of this analysis, a map of methods to optimise weld root topology is presented.

  19. Modern fiber laser beam welding of the newly-designed precipitation-strengthened nickel-base superalloys

    Science.gov (United States)

    Naffakh Moosavy, Homam; Aboutalebi, Mohammad-Reza; Seyedein, Seyed Hossein; Goodarzi, Massoud; Khodabakhshi, Meisam; Mapelli, Carlo; Barella, Silvia

    2014-04-01

    In the present research, the modern fiber laser beam welding of newly-designed precipitation-strengthened nickel-base superalloys using various welding parameters in constant heat input has been investigated. Five nickel-base superalloys with various Ti and Nb contents were designed and produced by Vacuum Induction Melting furnace. The fiber laser beam welding operations were performed in constant heat input (100 J mm-2) and different welding powers (400 and 1000 W) and velocities (40 and 100 mm s-1) using 6-axis anthropomorphic robot. The macro- and micro-structural features, weld defects, chemical composition and mechanical property of 3.2 mm weldments were assessed utilizing optical and scanning electron microscopes equipped with EDS analysis and microhardness tester. The results showed that welding with higher powers can create higher penetration-to-width ratios. The porosity formation was increased when the welding powers and velocities were increased. None of the welds displayed hot solidification and liquation cracks in 400 and 1000 W welding powers, but liquation phenomenon was observed in all the heat-affected zones. With increasing the Nb content of the superalloys the liquation length was increased. The changing of the welding power and velocity did not alter the hardness property of the welds. The hardness of welds decreased when the Ti content declined in the composition of superalloys. Finally, the 400 and 1000 W fiber laser powers with velocity of 40 and 100 m ms-1 have been offered for hot crack-free welding of the thin sheet of newly-designed precipitation-strengthened nickel-base superalloys.

  20. 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...... video pictures (400 Hz), a clear impact on the seam characteristics has been identified when a hump occurs.Finally, a clear correlation between the position of the focus point, the resultant process type and the corresponding signal intensity and signal variation has been found for sheets welded...

  1. Metals welding by using laser

    International Nuclear Information System (INIS)

    Al-Qaisy, R.A.W.

    1991-01-01

    In the present work, same welding ''conduction limited type'' under atmospheric conditions was performed using pulsed Ng:YAG laser to weld; low carbon steel (LCS), stainless steel (304) (SUS304), stainless steel (303) (SUS303), and brass. Microstructure of welded zone, heat affected zone (HAZ), and the laser energy on penetration depth and effective diameter were studied. Tensile test, micro-hardness, and surface roughness of welded and parent metals were also dealt with. Melting efficiency was worked out and an under vacuum seam welding of low carbon steel has been accomplished. Finally spot welding of aluminium tungsten, and platinium wires were employed using different layer energies. 34 tabs.; 82 figs.; 51 refs.; 1 app

  2. Corrosion of carbon steel welds

    International Nuclear Information System (INIS)

    Daniel, B.

    1988-09-01

    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)

  3. Magnetoencephalography study of different relationships among low- and high-frequency-band neural activities during the induction of peaceful and fearful audiovisual modalities among males and females.

    Science.gov (United States)

    Yang, Chia-Yen; Lin, Ching-Po

    2017-01-02

    Our previous study estimated the bias from the match attributes of the auditory and visual modalities related to a peaceful mood in the male brain. However, the interactions among the four main frequency bands of neural activity remain unknown. Therefore, this study uses magnetoencephalography to explore gender differences in the perceptions of auditory and visual modalities related to peaceful and fearful moods. Instead of analyzing single frequencies, this study analyzes interactions between low-frequency phase and high-frequency amplitude to reflect neural communication. The top four values in each of the 10 brain regions were averaged to give a representative value for further analysis with repeated-measures ANOVA. The results from the cross-frequency analyses suggest that delta-theta, delta-alpha, delta-beta, and delta-gamma couplings are associated with interactions between emotion and modality; theta-alpha, theta-beta, and theta-gamma couplings are associated with interactions between gender and emotion/time; alpha-beta and alpha-gamma couplings are associated with time; and beta-gamma coupling is associated with interactions between gender and modality. Although no obvious hemispheric lateralization of emotion in the macroscopic neural activity was found, these results reveal that males have stronger couplings (e.g., beta-gamma coupling) in the visual modality related to peaceful mood, whereas females have stronger couplings (e.g., beta-gamma coupling) in the audiovisual modality related to fearful mood. Gender differences become much more apparent when analysis is based on cross-frequency coupling. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  4. Spontaneous micronucleus frequencies in human peripheral blood lymphocytes as a screening test for an individual variation in a different population and radiation-induced micronucleus induction

    International Nuclear Information System (INIS)

    Kang, Chang-Mo; Jeon, Hye-Jeong; Cho, Chul-Koo

    2004-01-01

    Our studies were to evaluate the role of epigenetic factors in the variation of radiosensitivity on human peripheral blood lymphocytes by measuring the frequencies of micronucleus (MN) from 293 healthy subjects of different population for assessing the radiation health risk in Korea. We analyzed the frequencies of both spontaneous and in vitro 60 Co γ-rays or 50MeV neutron-induced MNs. The frequencies of spontaneous NMs not only vary greatly between individuals, but also working or living areas. The increased levels of cells with spontaneous MNs were observed with an increasing age. The frequencies of spontaneous MNs were significantly higher in females than in males. For both sexes, MN frequency was significantly and positively correlated with age. Age and gender are the most important demographic variables impacting on the MN index. Donors who had ever smoked showed significantly increased frequencies of MNs compared to nonsmokers. The main lifestyle factors influencing the MN index in the subjects are correlated significantly and positively with smoke while measuring the spontaneous frequencies of micronuclei. Therefore, it is evident that with regard to the application of MN assay all future studies to evaluate the association between radiosensitivity and susceptibility for radiation health risks in different populations should take into account the effect of age, gender and lifestyle. For the dose-response study, the induced MNs were observed at all doses, and the numerical changes according to doses. The dose-response curves were fitted with a linear-quadratic forms of the dose, and the results were different for γ-rays and neutrons significantly. Neutrons were more effective than γ-rays in producing MN with a dose-dependent manner. The frequency of MN varies with dose. The RBE for a micronuclei was 2.37 ± 0.17. The results suggested that the MN assay have a high potential to ensure appropriate quality control and a standard documentation protocol, which

  5. A high frequency of induction of chromosome aberrations in the bone marrow cells of LEC strain rats by X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Okui, Toyo (Hokkaido Inst. of Public Health, Sapporo (Japan)); Hayashi, Masanobu; Watanabe, Tomomasa; Namioka, Shigeo (Dept. of Lab. Animal Science, Hokkaido Univ., Sapporo (Japan)); Endoh, Daiji; Sato, Fumiaki (Dept. of Radiation Biology, Faculty of Veterinary Medicine, Hokkaido Univ., Sapporo (Japan)); Kasai, Noriyuki (Inst. for Animal Experimentation, Hokkaido Univ., Sapporo (Japan))

    1994-08-01

    LEC strain rats, which have been known to develop hereditarily spontaneous fulminant hepatitis 4 to 5 months after birth, are highly sensitive to whole-body X-irradiation when compared to WKAH strain rats. The present results showed that the frequencies of all types of chromosome aberrations induced by X-irradiation in the bone marrow cells of LEC rats were approximately 2- to 3-fold higher than those of WKAH rats, though no significant difference was observed in the frequency of spontaneous chromosome aberrations between LEC and WKAH rats.

  6. 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.

  7. Steel Collet For Welding Electrodes

    Science.gov (United States)

    Gilbert, Jeffrey L.; Gutow, David A.; Burley, Richard K.; Fogul, Irving

    1992-01-01

    Improved steel collet holds electrode for tungsten inert-gas welding but allows quick and easy replacement. Also ensures reliable arc starting. Slip-on compression ring compresses tapered section of body of collet around inner end of welding electrode. Collet mounted in receptacle below stack of lenses and filters in coaxial-vision welding torch. Blind hole in collet protects outermost lens from damage by electrode.

  8. The analysis of the quality of the frequency control of induction motor carried out on the basis of the processes in the rotor circuit

    Science.gov (United States)

    Kodkin, V. L.; Anikin, A. S.; Baldenkov, A. A.

    2018-01-01

    The results of researches of asynchronous electric drives with the frequency control which are carried out for the purpose of establishment of causes and effect relationships between a control method, the implementable standard frequency converter of the Schneider Electric company (ATV-71, ATV-32) and its efficiency are given in article. Tests with asynchronous motors with wound rotor were for the first time carried out. It allowed registering during the experiments the instantaneous values not only the stator currents, but also rotor currents. Authors for the first time applied spectrum analysis of stator and rotor currents, it showed that «sensorless vector» control leads to origin of high-frequency harmonicas with the considerable amplitude and, as a result of they are non-sinusoidal of the created torque and inefficiency of the electric drive. The accelerations that are carried out during the researches to 94, 157 and 251 Rad/s confirmed this feature of vector control that appears incapable to linearize the asynchronous electric drive as it was supposed authors of a method. These results do not contradict theoretical provisions if not to neglect assumptions which usually become in case of an output of the equations of vector control. Unfortunately, the modern researchers do not subject these assumptions to doubts. Continued studies make it possible to create an effective frequency management of asynchronous electric drives required for current technology.

  9. Hypnotic induction is followed by state-like changes in the organization of EEG functional connectivity in the theta and beta frequency bands in high-hypnotically susceptible individuals

    Science.gov (United States)

    Jamieson, Graham A.; Burgess, Adrian P.

    2014-01-01

    Altered state theories of hypnosis posit that a qualitatively distinct state of mental processing, which emerges in those with high hypnotic susceptibility following a hypnotic induction, enables the generation of anomalous experiences in response to specific hypnotic suggestions. If so then such a state should be observable as a discrete pattern of changes to functional connectivity (shared information) between brain regions following a hypnotic induction in high but not low hypnotically susceptible participants. Twenty-eight channel EEG was recorded from 12 high susceptible (highs) and 11 low susceptible (lows) participants with their eyes closed prior to and following a standard hypnotic induction. The EEG was used to provide a measure of functional connectivity using both coherence (COH) and the imaginary component of coherence (iCOH), which is insensitive to the effects of volume conduction. COH and iCOH were calculated between all electrode pairs for the frequency bands: delta (0.1–3.9 Hz), theta (4–7.9 Hz) alpha (8–12.9 Hz), beta1 (13–19.9 Hz), beta2 (20–29.9 Hz) and gamma (30–45 Hz). The results showed that there was an increase in theta iCOH from the pre-hypnosis to hypnosis condition in highs but not lows with a large proportion of significant links being focused on a central-parietal hub. There was also a decrease in beta1 iCOH from the pre-hypnosis to hypnosis condition with a focus on a fronto-central and an occipital hub that was greater in high compared to low susceptibles. There were no significant differences for COH or for spectral band amplitude in any frequency band. The results are interpreted as indicating that the hypnotic induction elicited a qualitative change in the organization of specific control systems within the brain for high as compared to low susceptible participants. This change in the functional organization of neural networks is a plausible indicator of the much theorized “hypnotic-state.” PMID:25104928

  10. Hypnotic Induction is followed by State-like changes in the organization of EEG Functional Connectivity in the Theta and Beta Frequency bands in high-hypnotically susceptible individuals

    Directory of Open Access Journals (Sweden)

    Graham eJamieson

    2014-07-01

    Full Text Available Altered state theories of hypnosis posit that a qualitatively distinct state of mental processing, which emerges in those with high hypnotic susceptibility following a hypnotic induction, enables the generation of anomalous experiences in response to specific hypnotic suggestions. If so then such a state should be observable as a discrete pattern of changes to functional connectivity (shared information between brain regions following a hypnotic induction in high but not low hypnotically susceptible participants. Twenty-eight channel EEG was recorded from 12 high susceptible (highs and 11 low susceptible (lows participants with their eyes closed prior to and following a standard hypnotic induction. The EEG was used to provide a measure of functional connectivity using both coherence (COH and the imaginary component of coherence (iCOH, which is insensitive to the effects of volume conduction. COH and iCOH were calculated between all electrode pairs for the frequency bands: delta (0.1–3.9Hz, theta (4–7.9Hz alpha (8–12.9Hz, beta1 (13–19.9Hz, beta2 (20–29.9Hz and gamma (30–45Hz. The results showed that there was an increase in theta iCOH from the pre-hypnosis to hypnosis condition in highs but not lows with a large proportion of significant links being focused on a central-parietal hub. There was also a decrease in beta1 iCOH from the pre-hypnosis to hypnosis condition with a focus on a fronto-central and an occipital hub that was greater in high compared to low susceptibles. There were no significant differences for COH or for spectral band amplitude in any frequency band. The results are interpreted as indicating that the hypnotic induction elicited a qualitative change in the organization of specific control systems within the brain for high as compared to low susceptible participants. This change in the functional organization of neural networks is a plausible indicator of the much theorized hypnotic-state.

  11. 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

    The post-welding stress state, strain history and material conditions of friction stir welded joints are often strongly idealized when used in subsequent modeling analyses, typically by neglecting one or more of the features above. But, it is obvious that the conditions after welding do influence...... 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...... the weld performance. The objective of this paper is to discuss some of the main conflicts that arise when taking both the post-welding material conditions and stressestrain state into account in a subsequent structural analysis. The discussion is here based on a preliminary numerical study of the possible...

  12. Reduction method for residual stress of welded joint using harmonic vibrational load

    International Nuclear Information System (INIS)

    Aoki, Shigeru; Nishimura, Tadashi; Hiroi, Tetsumaro; Hirai, Seiji

    2007-01-01

    Welding is widely used for construction of many structures. Since welding is a process using locally given heat, residual stress is generated near the bead. Tensile residual stress degrades fatigue strength. Some reduction methods of residual stress have been presented and, for example, heat treatment and shot peening are practically used. However, those methods need special tools and are time consuming. In this paper, a new method for reduction of residual stress using harmonic vibrational load during welding is proposed. The proposed method is examined experimentally for some conditions. Two thin plates are supported on the supporting device and butt-welded using an automatic CO 2 gas shielded arc welding machine. Residual stress in the direction of the bead is measured by using a paralleled beam X-ray diffractometer with scintillation counter after removing quenched scale chemically. First, the welding of rolled steel for general structure for some excitation frequencies is examined. Specimens are welded along the groove on both sides. For all frequencies, tensile residual stress near the bead is significantly reduced. Second, welding of the specimen made of high tensile strength steel is examined. In this case, tensile residual stress near the bead is also reduced. Finally, the proposed method is examined by an analytical method. An analytical model which consists of mass and preloaded springs with elasto-plastic characteristic is used. Reduction of residual stress is demonstrated using this model

  13. 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.

  14. The Effect of Weld Penetration on Blast Performance of Welded Panels

    Science.gov (United States)

    2014-08-01

    programmable robot as shown in Figure 6. The welding robot was used to maximise consistency between the welded coupons. Table 3 contains information regarding...Coupon Weld Characterisation Welding is an inherently variable process and while robotic welding provides better control of weld quality there is... robotic welding , while John Norrish provided advice and logistical support. At DSTO Edinburgh, John Williams performed the duties of firing and safety

  15. Prophage Induction by Ultraviolet Light in Acinetobacter calcoaceticus

    DEFF Research Database (Denmark)

    Berenstein, D.

    1986-01-01

    UV-induction of prophage P78 of Acinetobacter calcoaceticus increased with the UV-dose given to the lysogenic strain from the spontaneous induction frequency of about 0.8% to a maximal frequency of 10%. This 10- to 20-fold increase of induction frequency, as measured by the number of infective ce...

  16. Estudio del empleo de inversores resonantes de alta frecuencia en la recuperación de fuentes de soldadura; Study of the employment of high frequency resonant inverters in the recovery of welding sources

    Directory of Open Access Journals (Sweden)

    Jorge Luis Portal Gallardo

    2011-02-01

    Full Text Available En este artículo, se realizará un análisis pormenorizado de la evolución de las fuentes de soldadura en suúltima etapa, para plantear las previsiones futuras que se esperan en este campo que tanta importanciatiene en la actualidad. Por otra parte, y teniendo en cuenta los nuevos requerimientos de eficiencia yfiabilidad que se les exige a las fuentes de soldadura, es preciso analizar si la tecnología de fabricación deestas fuentes se encuentra tan madura como se dice o es preciso impulsarla más en algunos aspectosconcretos de la misma. In this article, it will be carried out an itemized analysis of the welding sources evolution in their last stage,to outline the future forecasts that are expected in this field that so much importance has at the presenttime. On the other hand, and keeping in mind the new requirements of efficiency and reliability that aredemanded to the welding sources, is necessary to analyze if the technology of production of these sourcesis as mature as it is said or it is necessary to impel it more in some concrete aspects of the same one.

  17. 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-soft......-software package ABAQUS. In this work, the results have been qualitatively evaluated....

  18. Sustainability of Welding Process through Bobbin Friction Stir Welding

    Science.gov (United States)

    Sued, M. K.; Samsuri, S. S. M.; Kassim, M. K. A. M.; Nasir, S. N. N. M.

    2018-03-01

    Welding process is in high demand, which required a competitive technology to be adopted. This is important for sustaining the needs of the joining industries without ignoring the impact of the process to the environment. Friction stir welding (FSW) is stated to be benefitting the environment through low energy consumption, which cannot be achieved through traditional arc welding. However, this is not well documented, especially for bobbin friction stir welding (BFSW). Therefore, an investigation is conducted by measuring current consumption of the machine during the BFSW process. From the measurement, different phases of BFSW welding process and its electrical demand are presented. It is found that in general total energy in BFSW is about 130kW inclusive of all identified process phases. The phase that utilise for joint formation is in weld phase that used the highest total energy of 120kWs. The recorded total energy is still far below the traditional welding technology and the conventional friction stir welding (CFSW) energy demand. This indicates that BFSW technology with its vast benefit able to sustain the joining technology in near future.

  19. Gas Tungsten Arc Welding. Welding Module 6. Instructor's Guide.

    Science.gov (United States)

    Missouri Univ., Columbia. Instructional Materials Lab.

    This guide is intended to assist vocational educators in teaching a three-unit module in gas tungsten arc welding. The module has been designed to be totally integrated with Missouri's Vocational Instruction Management System. The basic principles involved in gas tungsten arc welding, supplies, and applications are covered. The materials included…

  20. Shielded Metal Arc Welding. Welding Module 4. 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 shielded 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; theory, power sources, and…

  1. 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…

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

    International Nuclear Information System (INIS)

    Gibb, M.; Bala, S.R.

    1984-01-01

    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

  3. Laser welding of sheet metals

    Science.gov (United States)

    Xie, Jian

    Laser welding of sheet metals is an important application of high power lasers, and has many advantages over conventional welding techniques. Laser welding has a great potential to replace other welding technique in the car-body manufacturing because of high laser weld quality and relatively low manufacturing cost associated with the laser technique. However, a few problems related to the laser welding of sheet metals limit its applications in industries. To have a better understanding of the welding process, laser welding experimental studies and theoretical analysis are necessary. Temperature-dependent absorptivities of various metals are obtained theoretically for COsb2, COIL (Chemical Oxygen-Iodine Laser) and Nd:YAG lasers. It is found that the absorptivities for COIL and Nd:YAG lasers are 2.84 and 3.16 times higher than for the COsb2 laser, and the absorptivity increases with increasing temperature of the metals. Surface roughness and oxide films can enhance the absorption significantly. The reflectivity of as-received steel sheets decreases from 65-80% to 30-40% with surface oxide films for COsb2 lasers. Laser welding experiments show that the tensile strengths of the weld metals are higher than the base metals. For samples with surface oxide films, the oxygen concentration in the weld metals is found to be higher than in the specimens without oxidation, and the toughness of the weld metals is degraded. When steel powders are added to bridge the gap between two sheets, the oxygen content in the weld metals decreases and the toughness increases. A mathematical model is developed for the melt depth due to a stationary laser beam. The model results show that the melt depth increases rapidly with time at the beginning of laser irradiation and then increases slowly. Also, the melt depth is found to increase rapidly with laser intensities and then increases slowly for higher intensity. The average rate of melting and the times to reach the melting and boiling

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

    International Nuclear Information System (INIS)

    Kapitza, M.

    2001-01-01

    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.) [de

  5. Improving the Quality of Welding Seam of Automatic Welding of Buckets Based on TCP

    Science.gov (United States)

    Hu, Min

    2018-02-01

    Since February 2014, the welding defects of the automatic welding line of buckets have been frequently appeared. The average repair time of each bucket is 26min, which seriously affects the production efficiency and welding quality. We conducted troubleshooting, and found the main reasons for the welding defects of the buckets were the deviations of the center points of the robot tools and the poor quality of the locating welding. We corrected the gripper, welding torch, and accuracy of repeat positioning of robots to control the quality of positioning welding. The welding defect rate of buckets was reduced greatly, ensuring the production efficiency and welding quality.

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

    International Nuclear Information System (INIS)

    Jiang, Wenchun; Luo, Yun; Wang, B.Y.; Tu, S.T.; Gong, J.M.

    2014-01-01

    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

  7. Copper welding; Les liaisons du cuivre

    Energy Technology Data Exchange (ETDEWEB)

    Monneau, Ph. [SDMS, 38 - Saint-Romans (France)

    2000-07-01

    The following categories of manufactured copper: Cu-c ( > 99.95% copper and less than 0.0003% phosphor) and Cu-OF (oxygen free copper) are useful in vacuum or ultra-vacuum techniques. Homogeneous binding (or heterogeneous with other metals) are mainly performed by welding (TIG, MIG, FE) or by brazing at high or low temperatures. In this article these different methods are reviewed with pros and cons, and several applications are presented, particularly the designing of high frequency resonator cavities for GANIL accelerator, these cavities were made out of solid copper. (A.C.)

  8. Extremely low frequency pulsed electromagnetic fields cause antioxidative defense mechanisms in human osteoblasts via induction of •O2 − and H2O2

    OpenAIRE

    Ehnert, Sabrina; Fentz, Anne-Kristin; Schreiner, Anna; Birk, Johannes; Wilbrand, Benjamin; Ziegler, Patrick; Reumann, Marie K.; Wang, Hongbo; Falldorf, Karsten; Nussler, Andreas K.

    2017-01-01

    Recently, we identified a specific extremely low-frequency pulsed electromagnetic field (ELF-PEMF) that supports human osteoblast (hOBs) function in an ERK1/2-dependent manner, suggesting reactive oxygen species (ROS) being key regulators in this process. Thus, this study aimed at investigating how ELF-PEMF exposure can modulate hOBs function via ROS. Our results show that single exposure to ELF-PEMF induced ROS production in hOBs, without reducing intracellular glutathione. Repetitive exposu...

  9. Metal Working and Welding Operations.

    Science.gov (United States)

    Marine Corps Inst., Washington, DC.

    This student guide, one of a series of correspondence training courses designed to improve the job performance of members of the Marine Corps, deals with the skills needed by metal workers and welders. Addressed in the six individual units of the course are the following topics: weldable metals and their alloys, arc welding, gas welding,…

  10. Hybrid laser-arc welding

    DEFF Research Database (Denmark)

    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...

  11. 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. Th...

  12. Welding--Trade or Profession?

    Science.gov (United States)

    Albright, C. E.; Smith, Kenneth

    2006-01-01

    This article discusses a collaborative program between schools with the purpose of training and providing advanced education in welding. Modern manufacturing is turning to automation to increase productivity, but it can be a great challenge to program robots and other computer-controlled welding and joining systems. Computer programming and…

  13. Silver Nitrate and Different Culture Vessels Influence High Frequency Microrhizome Induction In Vitro and Enhancement Growth of Turmeric Plantlet During Ex Vitro Acclimatization

    Directory of Open Access Journals (Sweden)

    Dikash Singh THINGBAIJAM

    2012-11-01

    Full Text Available Eleven cultivars of C. longa var. Lakadong were collected from Manipur having different topography. Curcumin content in different cultivars has been analyzed by using UV-Visible Spectrophotometer (100 Bio-Carry Spectrophotometer. The curcuminoids content were analyzed and quantified for identification of best quality cultivar. Thoubal Cultivar with highest curcumin content (9.44% was subjected for tissue culture technique using different culture vessels and silver nitrate for rapid multiplication and scaling up of microrhizome production. High multiplication rate of 27.400.47 were obtained in Murashige and Skoogs medium supplemented with 3% sucrose + 1 mg L-1 ?-napthalene acetic acid, 4 mg L-1 6-benzyl-amino-purine and 11 ?M silver nitrate. Effect of different culture vessels and silver nitrate were studied for microrhizome and multiple shoots formation. Relatively higher rate of shoots along with microrhizome (17.50.32 can be seen in Growtek which was grown without any plant growth regulator. Growtek was used for scaling up of microrhizome production in vitro and utmost microrhizome was produced in liquid Murashige and Skoogs medium supplemented with 8% sucrose, 1 mg L-1 ?-napthalene acetic acid, 4 mg L-1 6-benzyl-amino-purine and 11 ?M silver nitrate (36.250.27. Addition of silver nitrate in the medium resulted in improvement of microrhizome induction in vitro. Higher concentration of silver nitrate (33, 44, 66, 88 ?M negatively affected the microrhizome and shoot multiplication and shows inhibition of tissue response completely. Analysis of in vitro derived plantlets during acclimatization shows that the exogenous applied of silver nitrate shows superior growth as compared to control. 90-95% of plantlets with and 75-80% plantlets without silver nitrate treatment were successfully established under ex vitro acclimatization. The protocol could be utilized for large scale production of true-to-type plantlets and as alternative method to step

  14. New technologies for Management of PWSCC in Dissimilar Metal Weld in NPPs

    International Nuclear Information System (INIS)

    Kim, Joung Soo; Kim, Hong Pyo

    2010-01-01

    One of big issues to increase structural integrity and operating efficiency of nuclear power plants(NPPs) is now primary water stress corrosion cracking(PWSCC) occurring in dissimilar metal weld(DMW) regions, such as, inlet and outlet nozzles, and J-welds of control rod drive mechanism (CRDM) penetration and bottom-mounted instrumentation(BMI) nozzles in a reactor pressure vessel, and other nozzles in a primary system. In order to manage the PWSCC occurring in DMW, many technologies, for example, an induction heating stress improvement(IHSI) process, a mechanical stress improvement process(MSIP), overlay and inlay welding processes using conventional welding methods, water jet or laser peening processes, etc., have been developed in nuclear-advanced counties. Many of them have been being applied to some operating NPPs in the world. The most reliable, relatively new, and effective technologies are, however, thought to be a laser peening and an inlay welding process using a under-water laser welding(UWLW) method. In this talk, the laser peening process and inlay welding process using UWLW method will be introduced and their advantages will be discussed

  15. New technologies for Management of PWSCC in Dissimilar Metal Weld in NPPs

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joung Soo; Kim, Hong Pyo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-10-15

    One of big issues to increase structural integrity and operating efficiency of nuclear power plants(NPPs) is now primary water stress corrosion cracking(PWSCC) occurring in dissimilar metal weld(DMW) regions, such as, inlet and outlet nozzles, and J-welds of control rod drive mechanism (CRDM) penetration and bottom-mounted instrumentation(BMI) nozzles in a reactor pressure vessel, and other nozzles in a primary system. In order to manage the PWSCC occurring in DMW, many technologies, for example, an induction heating stress improvement(IHSI) process, a mechanical stress improvement process(MSIP), overlay and inlay welding processes using conventional welding methods, water jet or laser peening processes, etc., have been developed in nuclear-advanced counties. Many of them have been being applied to some operating NPPs in the world. The most reliable, relatively new, and effective technologies are, however, thought to be a laser peening and an inlay welding process using a under-water laser welding(UWLW) method. In this talk, the laser peening process and inlay welding process using UWLW method will be introduced and their advantages will be discussed

  16. Metal ion release from silver soldering and laser welding caused by different types of mouthwash.

    Science.gov (United States)

    Erdogan, Ayse Tuygun; Nalbantgil, Didem; Ulkur, Feyza; Sahin, Fikrettin

    2015-07-01

    To compare metal ion release from samples welded with silver soldering and laser welding when immersed into mouthwashes with different ingredients. A total of 72 samples were prepared: 36 laser welded and 36 silver soldered. Four samples were chosen from each subgroup to study the morphologic changes on their surfaces via scanning electron microscopy (SEM). Each group was further divided into four groups where the samples were submerged into mouthwash containing sodium fluoride (NaF), mouthwash containing sodium fluoride + alcohol (NaF + alcohol), mouthwash containing chlorhexidine (CHX), or artificial saliva (AS) for 24 hours and removed thereafter. Subsequently, the metal ion release from the samples was measured with inductively coupled plasma mass spectrometry (ICP-MS). The metal ion release among the solutions and the welding methods were compared. The Kruskal-Wallis and analysis of variance (ANOVA) tests were used for the group comparisons, and post hoc Dunn multiple comparison test was utilized for the two group comparisons. The level of metal ion release from samples of silver soldering was higher than from samples of laser welding. Furthermore, greater amounts of nickel, chrome, and iron were released from silver soldering. With regard to the mouthwash solutions, the lowest amounts of metal ions were released in CHX, and the highest amounts of metal ions were released in NaF + alcohol. SEM images were in accord with these findings. The laser welding should be preferred over silver soldering. CHX can be recommended for patients who have welded appliances for orthodontic reasons.

  17. 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.

  18. Scanning of electron beam by X-shaped trajectory as a means of root weld defect minimizing in EBW

    International Nuclear Information System (INIS)

    Belen'kij, V.Ya.

    1986-01-01

    The application of X-shaped electron beam scanning for welding to eliminate peak-formation and accompanying root weld defects. It is shown that the use of X-shaped scanning allows one to attain substantial decrease of root penetration peaks amplitude with a slight decrease of its depth. It is advisable to perform welding with optimum electron beam focusing which can be established by maximum value of oscillations amplitude of the alternating-current spectrum component in the circuit of the welded product or collector with frequency in the 3-15 kHz range with motionless as well as oscillating beam

  19. 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...... of normal video and high speed video (100 Hz) can not reveal any instability in the process when humping occurs. Contrary to this, photo diode signals (sampled at 3 kHz) clearly indicate a characteristic signal when humps occur.When the seam area and seam width have manually been measured on high speed...

  20. Laser welding of tailored blanks

    International Nuclear Information System (INIS)

    Pecas, P.; Gouveia, H.; Quintino, L.; Olsen, F.O.

    1998-01-01

    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 CO 2 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

  1. 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

  2. Tailor-welded blanks and their production

    Science.gov (United States)

    Yan, Qi

    2005-01-01

    Tailor welded blanks had been widely used in the automobile industry. A tailor welded blank consists of several flat sheets that were laser welded together before stamping. A combination of different materials, thickness, and coatings could be welded together to form a blank for stamping car body panels. As for the material for automobile industry, this technology was one of the development trend for automobile industry because of its weight reduction, safety improvement and economical use of materials. In this paper, the characters and production of tailor welded blanks in the market were discussed in detail. There had two major methods to produce tailor welded blanks. Laser welding would replace mesh seam welding for the production of tailor welded blanks in the future. The requirements on the edge preparation of unwelded blanks for tailor welded blanks were higher than the other steel processing technology. In order to produce the laser welded blank, there had the other process before the laser welding in the factory. In the world, there had three kinds of patterns for the large volume production of tailor welded blanks. In China, steel factory played the important role in the promotion of the application of tailor welded blanks. The competition for the supply of tailor welded blanks to the automobile industry would become fierce in the near future. As a result, the demand for the quality control on the production of tailor welded blanks would be the first priority concern for the factory.

  3. 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 in...

  4. 49 CFR 195.214 - Welding procedures.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Welding procedures. 195.214 Section 195.214... PIPELINE Construction § 195.214 Welding procedures. (a) Welding must be performed by a qualified welder in accordance with welding procedures qualified under Section 5 of API 1104 or Section IX of the ASME Boiler and...

  5. Electron beam welding fundamentals and applications

    International Nuclear Information System (INIS)

    Mara, G.L.; Armstrong, R.E.

    1975-01-01

    The electron beam welding process is described and the unique mode of operation and penetration explained by a description of the forces operating within the weld pool. This penetration model is demonstrated by high speed cinematography of the weld pool on several materials. The conditions under which weld defects are formed are discussed and examples are presented. (auth)

  6. 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...

  7. 46 CFR 154.660 - Pipe welding.

    Science.gov (United States)

    2010-10-01

    ... butt welds must meet the following: (1) Butt welds of pipes made from carbon, carbon manganese, or low alloy steels must meet § 56.50-105 of this chapter, including the requirements for post-weld heat treatment. (2) Except for piping inside an independent cargo tank type A, B, or C, butt welds must be 100...

  8. Clamp and Gas Nozzle for TIG Welding

    Science.gov (United States)

    Gue, G. B.; Goller, H. L.

    1982-01-01

    Tool that combines clamp with gas nozzle is aid to tungsten/inert-gas (TIG) welding in hard-to-reach spots. Tool holds work to be welded while directing a stream of argon gas at weld joint, providing an oxygen-free environment for tungsten-arc welding.

  9. Observation and Simulation of Axle Box Acceleration in the Presence of Rail Weld in High-Speed Railway

    Directory of Open Access Journals (Sweden)

    Boyang An

    2017-12-01

    Full Text Available Rail welds are widely used in high-speed railways and short-wave irregularities usually appear due to limitations in welding technology. These irregularities can excite a high wheel/rail force and are regarded as the main cause of deterioration in track structures. To measure this fierce force (or deterioration of the rail weld, axle box acceleration is treated as an effective and economic measure, though an exact quantitative relation between these two quantities remains elusive. This paper aims to develop such a relation in order to provide a new theoretical basis and an analysis method for monitoring and controlling weld geometry irregularity. To better understand the characteristics of axle box acceleration, the paper consists of two parts: an observation and a numerical simulation of axle box acceleration by rail welds. Based on measured data from field tests, axle box acceleration at rail welds was found to have high-frequency vibrations in two frequency bands (i.e., 350–500 Hz and 1000–1200 Hz. Upon analyzing the vibration characteristics in time–frequency domains, the exact location of the rail weld irregularity could be identified. Subsequently, a 3D high-speed wheel/rail rolling contact finite element model was employed to investigate the effect of rail weld geometry on axle box acceleration, and led to the discovery that the weld length and depth determine the vibration frequency and amplitude of the axle box acceleration, respectively. A quantitative relation between axle box acceleration and wheel/rail force has also been determined. Finally, we propose an approach for real-time health detection of rail welds and discuss the influence of other defects and rail welds on the acceleration signal of the axle box.

  10. Ultrasonic Guided Wave Propagation through Welded Lap Joints

    Directory of Open Access Journals (Sweden)

    Audrius Jankauskas

    2016-12-01

    Full Text Available The objective of the research presented here is the investigation of ultrasonic guided wave (UGW propagation through the lap joint welded plates used in the construction of a storage tank floors. The investigations have been performed using numerical simulation by finite element method (FEM and tested by measurement of the transmission losses of the guided waves transmitted through the welded lap joints. Propagation of the symmetric S0 mode in the welded stainless steel plates in the cases of different lap joint overlap width, operation frequency, and additional plate bonding caused by corrosion were investigated. It was shown that the transmission losses of the S0 mode can vary in the range of 2 dB to 8 dB depending on the ratio between lap joint width and wavelength. It was also demonstrated that additional bonding in the overlap zone caused by corrosion can essentially reduce transmission losses.

  11. Induction period

    International Nuclear Information System (INIS)

    Land, C.E.; Tokunaga, M.

    1984-01-01

    Induction period is the temporal aspect of the excess cancer risk that follows an exposure to ionizing radiation. Operationally, it can be thought of as the time from an exposure of brief duration to the diagnosis of any resultant cancer. Whereas the magnitude of excess risk can be described by a single number, such as the average yearly excess risk over some fixed time interval after exposure, the temporal distribution requires a histogram or a curve, that is, an array or continuum of numbers. The study of induction period involves a search for a simple way of describing the temporal distribution of risk, that is, a way of describing a continuum by using only one or two numbers. In other words, the goal is to describe induction period probabilistically, using a parametric model with a few parameters

  12. Induction Brazing

    DEFF Research Database (Denmark)

    Henningsen, Poul

    Induction brazing is a fast and appropriate method for industrial joining of complex geometries and metal combinations. In all types of brazing processes it is important to heat the joint interface of the two materials to the same, high temperature. If one of the specimens is warmer than the other...... materials has large influence on the heating time and temperature distribution in induction heating. In order to ensure high and uniform temperature distribution near the interface of a joint between dissimilar materials the precise coil geometry and position is of great importance. The present report...... presents a combined numerical and experimental method for determination of appropriate/optimiged coil geometry and position in induction brazing tube-to-plate joints of different ratios between tube and plate thickness and different combinations of the materials stainless steel, brass and copper...

  13. Induction accelerators

    CERN Document Server

    Takayama, Ken

    2011-01-01

    A broad class of accelerators rests on the induction principle whereby the accelerating electrical fields are generated by time-varying magnetic fluxes. Particularly suitable for the transport of bright and high-intensity beams of electrons, protons or heavy ions in any geometry (linear or circular) the research and development of induction accelerators is a thriving subfield of accelerator physics. This text is the first comprehensive account of both the fundamentals and the state of the art about the modern conceptual design and implementation of such devices. Accordingly, the first part of the book is devoted to the essential features of and key technologies used for induction accelerators at a level suitable for postgraduate students and newcomers to the field. Subsequent chapters deal with more specialized and advanced topics.

  14. Induction practice -

    DEFF Research Database (Denmark)

    Rohde, Nicolas; Sprogøe, Jonas

    2007-01-01

    Research on induction of newcomers is primarily focused on individual processes, such as acquisition of knowledge and socialization in order to create a smooth and frictionless entry period. The interest of our research, however, is the processes that happen on the organizational level. We claim...... that induction potentially triggers both individual and organizational learning and by drawing on practice-based theory we discuss how the interplay between individual and the organization, what we call agenerative dance, ignites both kinds of learning. We focus on and describe the interplay , ignites both kinds...... of learning. We focus on and describe the interplay that takes place in particular induction events and analyze the "dance" through the lens of learning. The paper concludes with a brief discussion about the implications for practitioners and the challenges and future research prospects we have encountered...

  15. Machine for welding solar cell connections

    Energy Technology Data Exchange (ETDEWEB)

    Lorans, D.Y.

    1977-08-09

    A machine for welding a connection wire over a solar cell electrode is described which comprises a base, a welding mount for the solar cell which is supported on the base, means for holding the solar cell on the welding mount, welding electrodes, means to lower the welding electrodes over the solar cell and the connection wire superimposed thereon, means for applying electric current pulses to said welding electrodes. It is characterized by the fact that it further comprises means for imparting to said mount an alternating transverse movement in relation to said base before and during the welding operation.

  16. Method for controlling gas metal arc welding

    Science.gov (United States)

    Smartt, H.B.; Einerson, C.J.; Watkins, A.D.

    1987-08-10

    The heat input and mass input in a Gas Metal Arc welding process are controlled by a method that comprises calculating appropriate values for weld speed, filler wire feed rate and an expected value for the welding current by algorithmic function means, applying such values for weld speed and filler wire feed rate to the welding process, measuring the welding current, comparing the measured current to the calculated current, using said comparison to calculate corrections for the weld speed and filler wire feed rate, and applying corrections. 3 figs., 1 tab.

  17. Silver Nitrate and Different Culture Vessels Influence High Frequency Microrhizome Induction In Vitro and Enhancement Growth of Turmeric Plantlet During Ex Vitro Acclimatization

    Directory of Open Access Journals (Sweden)

    Dikash Singh THINGBAIJAM

    2012-11-01

    Full Text Available Eleven cultivars of C. longa var. Lakadong were collected from Manipur having different topography. Curcumin content in different cultivars has been analyzed by using UV-Visible Spectrophotometer (100 Bio-Carry Spectrophotometer. The curcuminoids content were analyzed and quantified for identification of best quality cultivar. Thoubal Cultivar with highest curcumin content (9.44% was subjected for tissue culture technique using different culture vessels and silver nitrate for rapid multiplication and scaling up of microrhizome production. High multiplication rate of 27.40�0.47 were obtained in Murashige and Skoog�s medium supplemented with 3% sucrose + 1 mg L-1 ?-napthalene acetic acid, 4 mg L-1 6-benzyl-amino-purine and 11 ?M silver nitrate. Effect of different culture vessels and silver nitrate were studied for microrhizome and multiple shoots formation. Relatively higher rate of shoots along with microrhizome (17.5�0.32 can be seen in Growtek which was grown without any plant growth regulator. Growtek was used for scaling up of microrhizome production in vitro and utmost microrhizome was produced in liquid Murashige and Skoog�s medium supplemented with 8% sucrose, 1 mg L-1 ?-napthalene acetic acid, 4 mg L-1 6-benzyl-amino-purine and 11 ?M silver nitrate (36.25�0.27. Addition of silver nitrate in the medium resulted in improvement of microrhizome induction in vitro. Higher concentration of silver nitrate (33, 44, 66, 88 ?M negatively affected the microrhizome and shoot multiplication and shows inhibition of tissue response completely. Analysis of in vitro derived plantlets during acclimatization shows that the exogenous applied of silver nitrate shows superior growth as compared to control. 90-95% of plantlets with and 75-80% plantlets without silver nitrate treatment were successfully established under ex vitro acclimatization. The protocol could be utilized for large scale production of true-to-type plantlets and as alternative

  18. An algorithm for the analysis of inductive antennas of arbitrary cross-section for heating in the ion cyclotron range of frequencies

    International Nuclear Information System (INIS)

    Lehrman, I.S.; Colestock, P.L.

    1986-10-01

    The application of Ion Cyclotron Range of Frequency (ICRF) heating to near ignited plasmas will require launching structures that will be capable of withstanding the harsh plasma environment. The recessed antenna configuration is expected to provide sufficient protection for the structure, but to date no analysis has been done to determine if adequate coupling can be achieved in such a configuration. In this work we present a method for determining the current distribution for the antenna in the direction transverse to current flow and predict antenna loading in the presence of plasma. Antennas of arbitrary cross section are analyzed above ground planes of arbitrary shape. Results from ANDES, the ANtenna DESign code, are presented and compared to experimental results

  19. Plasma spot welding of ferritic stainless steels

    International Nuclear Information System (INIS)

    Lesnjak, A.; Tusek, J.

    2002-01-01

    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% H 2 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

  20. Identification of Damaged Spot Welds in a Complicated Joined Structure

    Energy Technology Data Exchange (ETDEWEB)

    Yunus, M A; Rani, M N Abdul; Ouyang, H; Deng, H; James, S, E-mail: h.ouyang@liverpool.ac.uk [Department of Engineering, Harrison Hughes Building, University of Liverpool, Brownlow Hill, Liverpool L69 3GH (United Kingdom)

    2011-07-19

    In automotive engineering, spot welds on assembled structures such as Body in White (BiW) have a significant effect on the vehicles' dynamic characteristics. Understandably, imperfections in the spot welds will cause variations in the dynamic properties such as natural frequencies and mode shapes of the structure. In this paper, a complicated welded structure which is a simplified Natural Gas Vehicle (NGV) platform is investigated. The structure fabricated from thin metal sheets consists of ten components. They are jointed together by a number of scattered spot welds. NASTRAN Solution 200 based on sensitivity analysis is used to identify the most sensitive parameters to natural frequencies. The numerical model of the undamaged structure is initially updated in order to minimise the discrepancies between the measured and numerical data using NASTRAN optimisation code. The initial updated model serves as a benchmark for the subsequent structural damage identification. The numerical data of the benchmark model is then compared with the measured data obtained from the damaged structure. The same updating procedure is applied to the benchmark model in order to bring the numerical data as close as possible to the measured data of the damaged structure. The disparity in certain parameter values from the parameter values used in the benchmark model shows a fault or damage in the location of a particular joint, depending on the severity of this disparity. The challenge in this work is to localise damaged area and quantify the damage of the complicated structure with multiple spot welds in the presence of uncertainty in the location and material properties of the welds.

  1. Versatile Friction Stir Welding/Friction Plug Welding System

    Science.gov (United States)

    Carter, Robert

    2006-01-01

    A proposed system of tooling, machinery, and control equipment would be capable of performing any of several friction stir welding (FSW) and friction plug welding (FPW) operations. These operations would include the following: Basic FSW; FSW with automated manipulation of the length of the pin tool in real time [the so-called auto-adjustable pin-tool (APT) capability]; Self-reacting FSW (SRFSW); SR-FSW with APT capability and/or real-time adjustment of the distance between the front and back shoulders; and Friction plug welding (FPW) [more specifically, friction push plug welding] or friction pull plug welding (FPPW) to close out the keyhole of, or to repair, an FSW or SR-FSW weld. Prior FSW and FPW systems have been capable of performing one or two of these operations, but none has thus far been capable of performing all of them. The proposed system would include a common tool that would have APT capability for both basic FSW and SR-FSW. Such a tool was described in Tool for Two Types of Friction Stir Welding (MFS- 31647-1), NASA Tech Briefs, Vol. 30, No. 10 (October 2006), page 70. Going beyond what was reported in the cited previous article, the common tool could be used in conjunction with a plug welding head to perform FPW or FPPW. Alternatively, the plug welding head could be integrated, along with the common tool, into a FSW head that would be capable of all of the aforementioned FSW and FPW operations. Any FSW or FPW operation could be performed under any combination of position and/or force control.

  2. Process Parameter Optimization for Wobbling Laser Spot Welding of Ti6Al4V Alloy

    Science.gov (United States)

    Vakili-Farahani, F.; Lungershausen, J.; Wasmer, K.

    Laser beam welding (LBW) coupled with "wobble effect" (fast oscillation of the laser beam) is very promising for high precision micro-joining industry. For this process, similarly to the conventional LBW, the laser welding process parameters play a very significant role in determining the quality of a weld joint. Consequently, four process parameters (laser power, wobble frequency, number of rotations within a single laser pulse and focused position) and 5 responses (penetration, width, heat affected zone (HAZ), area of the fusion zone, area of HAZ and hardness) were investigated for spot welding of Ti6Al4V alloy (grade 5) using a design of experiments (DoE) approach. This paper presents experimental results showing the effects of variating the considered most important process parameters on the spot weld quality of Ti6Al4V alloy. Semi-empirical mathematical models were developed to correlate laser welding parameters to each of the measured weld responses. Adequacies of the models were then examined by various methods such as ANOVA. These models not only allows a better understanding of the wobble laser welding process and predict the process performance but also determines optimal process parameters. Therefore, optimal combination of process parameters was determined considering certain quality criteria set.

  3. Ultrasonic Spot and Torsion Welding of Aluminum to Titanium Alloys: Process, Properties and Interfacial Microstructure

    Science.gov (United States)

    Balle, Frank; Magin, Jens

    Hybrid lightweight structures shape the development of future vehicles in traffic engineering and the aerospace industry. For multi-material concepts made out of aluminum and titanium alloys, the ultrasonic welding technique is an alternative effective joining technology. The overlapped structures can be welded in the solid state, even without gas shielding. In this paper the conventional ultrasonic spot welding with longitudinal oscillation mode is compared to the recent ultrasonic torsion welding with a torsional mode at 20 kHz working frequency. For each technique the process parameters welding force, welding energy and oscillation amplitude were optimized for the hybrid joints using design of experiments. Relationships between the process parameters, mechanical properties and related welding zone should be understood. Central aspects of the research project are microscopic studies of the joining zone in cross section and extensive fracture surface analysis. Detailed electron microscopy and spectroscopy of the hybrid interface help to understand the interfacial formation during ultrasonic welding as well as to transfer the gained knowledge for further multi-metal joints.

  4. Real time computer controlled weld skate

    Science.gov (United States)

    Wall, W. A., Jr.

    1977-01-01

    A real time, adaptive control, automatic welding system was developed. This system utilizes the general case geometrical relationships between a weldment and a weld skate to precisely maintain constant weld speed and torch angle along a contoured workplace. The system is compatible with the gas tungsten arc weld process or can be adapted to other weld processes. Heli-arc cutting and machine tool routing operations are possible applications.

  5. 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...... temperature (CPT) test as corrosion test. The following welding parameters are varied: Welding speed, lsser power, focus point position and laser operation mode (CW or pulsed)....

  6. Weld Magnification Factor Approach in Cruciform Joints Considering Post Welding Cooling Medium and Weld Size

    Directory of Open Access Journals (Sweden)

    Oscar Araque

    2018-01-01

    Full Text Available The objective of this research is to develop an experimental-theoretical analysis about the influence of the cooling medium and the geometry of the welding bead profile in fatigue life and the associated parameters with structural integrity of welded joints. A welded joint with cruciform geometry is considered using SMAW (Shielded Metal ArcWelding, plates in structural steel ASTM A36 HR of 8 mm of thickness, and E6013 electrode input. A three-dimensional computational model of the cruciform joint was created using the finite element method. For this model, the surface undulation of the cord and differentiation in the mechanical properties of the fusion zone were considered, the heat-affected zone (HAZ and base material, respectively. In addition, an initial residual stress field, which was established experimentally, was considered. The results were a set of analytical expressions for the weld magnification factor Mk. It was found that values for the latter decrease markedly in function of the intensity of the cooling medium used in the post welding cooling phase, mainly due to the effect of the residual compressive stresses. The obtained models of behavior of the weld magnification factor are compared with the results from other researchers with some small differences, mainly due to the inclusion of the cooling effect of the post weld and the variation of the leg of the weld bead. The obtained analytical equations in the present research for Mk can be used in management models of life and structural integrity for this type of welded joint.

  7. Application of reliability techniques to prioritize BWR [boiling water reactor] recirculation loop welds for in-service inspection

    International Nuclear Information System (INIS)

    Holman, G.S.

    1989-12-01

    In January 1988 the US Nuclear Regulatory Commission issued Generic Letter 88-01 together with NUREG-0313, Revision 2, ''Technical Report on Material Selection and Processing Guidelines for BWR Coolant Pressure Boundary Piping,'' to implement NRC long-range plans for addressing the problem of stress corrosion cracking in boiling water reactor piping. NUREG-0313 presents guidelines for categorizing BWR pipe welds according to their SCC condition (e.g., presence of known cracks, implementation of measures for mitigating SCC) as well as recommended inspection schedules (e.g., percentage of welds inspected, inspection frequency) for each weld category. NUREG-0313 does not, however, specify individual welds to be inspected. To address this issue, the Lawrence Livermore National Laboratory developed two recommended inspection samples for welds in a typical BWR recirculation loop. Using a probabilistic fracture mechanics model, LLNL prioritized loop welds on the basis of estimated leak probabilities. The results of this evaluation indicate that riser welds and bypass welds should be given priority attention over other welds. Larger-diameter welds as a group can be considered of secondary importance compared to riser and bypass welds. A ''blind'' comparison between the probability-based inspection samples and data from actual field inspections indicated that the probabilistic analysis generally captured the welds which the field inspections identified as warranting repair or replacement. Discrepancies between the field data and the analytic results can likely be attributed to simplifying assumptions made in the analysis. The overall agreement between analysis and field experience suggests that reliability techniques -- when combined with historical experience -- represent a sound technical basis on which to define meaningful weld inspection programs. 13 refs., 8 figs., 5 tabs

  8. Implications of various intensities of radio frequency electromagnetic radiation (462 MHz in the induction of oxidative stress during the germination of Hippophae rhamnoides seeds

    Directory of Open Access Journals (Sweden)

    Calin Lucian Maniu

    2010-02-01

    Full Text Available The data accumulated by now shows that the topic of biological effects of electromagnetic radiation is far from being exhausted. Is undoubtedly that a non-ionizing radiation field maintained on a biological entity has some effects on it. To try shaping issues regarding this, this work aims to study the impact of radiation generated by an emission-reception radio station that emits on 462.6875 MHz frequency. For this purpose, were used Hippophae rhamnoides L. seeds which germinated in the laboratory, under controlled conditions, concentrically arranged around the radiation source, in which case electromagnetic radiation has a different impact. Seed germination lasted 35 days, while the device has continuously worked, and the seeds were constantly irradiated. It was precisely measured the intensity of the magnetic component of the field in all places where the seeds were placed for germination. It was calculated the percentage of germination and it was determined the enzyme activity involved in eliminating the oxidative stress effects. It was found significant variations of the parameters mentioned above in conjunction with the radiation intensity depending on the distance from the source.

  9. Control of Gas Tungsten Arc welding pool shape by trace element addition to the weld pool

    Science.gov (United States)

    Heiple, C.R.; Burgardt, P.

    1984-03-13

    An improved process for Gas Tungsten Arc welding maximizes the depth/width ratio of the weld pool by adding a sufficient amount of a surface active element to insure inward fluid flow, resulting in deep, narrow welds. The process is especially useful to eliminate variable weld penetration and shape in GTA welding of steels and stainless steels, particularly by using a sulfur-doped weld wire in a cold wire feed technique.

  10. Laser welding of fused quartz

    Science.gov (United States)

    Piltch, Martin S.; Carpenter, Robert W.; Archer, III, McIlwaine

    2003-06-10

    Refractory materials, such as fused quartz plates and rods are welded using a heat source, such as a high power continuous wave carbon dioxide laser. The radiation is optimized through a process of varying the power, the focus, and the feed rates of the laser such that full penetration welds may be accomplished. The process of optimization varies the characteristic wavelengths of the laser until the radiation is almost completely absorbed by the refractory material, thereby leading to a very rapid heating of the material to the melting point. This optimization naturally occurs when a carbon dioxide laser is used to weld quartz. As such this method of quartz welding creates a minimum sized heat-affected zone. Furthermore, the welding apparatus and process requires a ventilation system to carry away the silicon oxides that are produced during the welding process to avoid the deposition of the silicon oxides on the surface of the quartz plates or the contamination of the welds with the silicon oxides.

  11. 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...

  12. Nondestructive testing of weldings

    International Nuclear Information System (INIS)

    Ruth, U.

    1984-02-01

    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.) [de

  13. Metamaterial for Radar Frequencies

    Science.gov (United States)

    2012-09-01

    capacitive coupling with adjacent patches, as shown in Figure 3. The via provides inductance to ground. Figure 3. (a) Planar LH distributed periodic...After [20]). The capacitance in the structure balances out the inductance present when the cylinder is placed in a square array. The metallic... RADAR FREQUENCIES by Szu Hau Tan September 2012 Thesis Advisor: David C. Jenn Second Reader: James Calusdian

  14. Extremely low frequency pulsed electromagnetic fields cause antioxidative defense mechanisms in human osteoblasts via induction of •O2- and H2O2.

    Science.gov (United States)

    Ehnert, Sabrina; Fentz, Anne-Kristin; Schreiner, Anna; Birk, Johannes; Wilbrand, Benjamin; Ziegler, Patrick; Reumann, Marie K; Wang, Hongbo; Falldorf, Karsten; Nussler, Andreas K

    2017-11-06

    Recently, we identified a specific extremely low-frequency pulsed electromagnetic field (ELF-PEMF) that supports human osteoblast (hOBs) function in an ERK1/2-dependent manner, suggesting reactive oxygen species (ROS) being key regulators in this process. Thus, this study aimed at investigating how ELF-PEMF exposure can modulate hOBs function via ROS. Our results show that single exposure to ELF-PEMF induced ROS production in hOBs, without reducing intracellular glutathione. Repetitive exposure (>3) to ELF-PEMF however reduced ROS-levels, suggesting alterations in the cells antioxidative stress response. The main ROS induced by ELF-PEMF were •O 2 - and H 2 O 2 , therefore expression/activity of antioxidative enzymes related to these ROS were further investigated. ELF-PEMF exposure induced expression of GPX3, SOD2, CAT and GSR on mRNA, protein and enzyme activity level. Scavenging •O 2 - and H 2 O 2 diminished the ELF-PEMF effect on hOBs function (AP activity and mineralization). Challenging the hOBs with low amounts of H 2 O 2 on the other hand improved hOBs function. In summary, our data show that ELF-PEMF treatment favors differentiation of hOBs by producing non-toxic amounts of ROS, which induces antioxidative defense mechanisms in these cells. Thus, ELF-PEMF treatment might represent an interesting adjunct to conventional therapy supporting bone formation under oxidative stress conditions, e.g. during fracture healing.

  15. 3-D design method for welding groove and seal weld of reactor CRDM adapter

    International Nuclear Information System (INIS)

    Ma Baiyong; Wang Xiaobin; Zhu Xiaoyong

    2008-01-01

    Based on the analysis of 2 D and 3 D shapes of welding groove and seal weld of reactor CRDM adapter, four intersecting curves are defined, and a method and gist to 3 D design of adapter welding groove and seal weld is proposed. Parameterized design of adapter welding groove and seal weld has been realized using UG software, and the main factors which affect the welding section areas have been analyzed. Compared with the measurement, the error of weld section area of each adapter created by spline fitting method is less than 0.8%. (authors)

  16. 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...

  17. Review of laser hybrid welding

    DEFF Research Database (Denmark)

    Bagger, Claus

    2004-01-01

    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....

  18. Acoustic field measurements in austenitic welds and dissimilar welds

    International Nuclear Information System (INIS)

    Kemnitz, P.; Richter, U.

    1997-01-01

    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) [de

  19. 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.

  20. Fatigue life estimation of welded joints of an aluminium alloy under superimposed random load waves (follow-up report). Effects of high frequency components; Jujo random kajuka ni okeru aluminium gokin yosetsu tsugite no hiro jumyo suitei (zokuho). Koshuha seibun no eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, I.; Maenaka, H.; Takada, A. [Ship Research Inst., Tokyo (Japan)

    1996-12-31

    In order to examine fatigue behavior of boxing welded joints of anticorrosion aluminum A 5083 P-O alloy, the residual stress measurements, static loading tests, elastic finite element analyses, constant amplitude fatigue tests, and random fatigue tests were conducted. For a load wave in the random loading fatigue tests, a direct current component, a zero-mean narrow band random process, and a high frequency component were combined and superimposed, to examine the effect of the high frequency component and the effect of the stress cycle count method and the mean stress correction on the life estimation. For the fatigue analysis, a reference stress, such as that considering the structural stress concentration, was proved effective in reducing the amount of scattering in the fatigue test results and in improving the life estimation accuracy. Accordingly, for the actual scale measurements, it is insufficient only to measure the stress at points far from the crack initiation place. It is required to analyze the fatigue by measuring the reference stress same as the basic data acquisition tests in the laboratory. 4 refs., 21 figs., 4 tabs.

  1. Dictionary: Welding, cutting and allied processes. Pt. 2

    International Nuclear Information System (INIS)

    Kleiber, A.W.

    1987-01-01

    The dictionary contains approximately 40 000 entries covering all aspects of welding technology. It is based on the evaluation of numerous English, American and German sources. This comprehensive and up to date dictionary will be a reliable and helpful aid in evaluation and translating. The dictionary covers the following areas: Welding: gas welding, arc welding, gas shielded welding, resistance welding, welding of plastics, special welding processes; Cutting: flame cutting, arc cutting and special thermal cutting processes; Soldering: brazing and soldering; Other topics: thermal spraying, metal to metal adhesion, welding filler materials and other consumables, test methods, plant and equipment, accessories, automation, welding trade, general welding terminology. (orig./HP) [de

  2. Materials participation in welded joints manufacturing

    Science.gov (United States)

    Ghenghea, L. D.

    2016-08-01

    Management of materials dilution to form a joint with higher features asked by complex metallic structures is a problem that took attention and efforts of welding processes researchers and this communication will give a little contribution presenting some scientific and experimental results of dilution processes studied by Welding Research Group from Iasi, Romania, TCM Department. Liquid state welding processes have a strong dependence related to dilution of base and filler materials, the most important are for automatic joining using welding. The paper presents a review of some scientific works already published and their contributions, results of dilution coefficient evaluation using weighing, graphics and software applied for shielded metal arc welding process. Paper results could be used for welders’ qualification, welding procedure specification and other welding processes researchers’ activities. The results of Welding Research Group from Iasi, Romania, TCM Department, show dilution coefficient values between 20-30 % of base material and 70-80 % of filler material for studied welding process.

  3. Gas Shielding Technology for Welding and Brazing

    Science.gov (United States)

    Nunes, Arthur J.; Gradl, Paul R.

    2012-01-01

    Welding is a common method that allows two metallic materials to be joined together with high structural integrity. When joints need to be leak-tight, light-weight, or free of contaminant-trapping seams or surface asperities, welding tends to be specified. There are many welding techniques, each with its own advantages and disadvantages. Some of these techniques include Forge Welding, Gas Tungsten Arc Welding, Friction Stir Welding, and Laser Beam Welding to name a few. Whichever technique is used, the objective is a structural joint that meets the requirements of a particular component or assembly. A key practice in producing quality welds is the use of shielding gas. This article discusses various weld techniques, quality of the welds, and importance of shielding gas in each of those techniques. Metallic bonds, or joints, are produced when metals are put into intimate contact. In the solid-state "blacksmith welding" process, now called Forge Welding (FOW), the site to be joined is pounded into intimate contact. The surfaces to be joined usually need to be heated to make it easier to deform the metal. The surfaces are sprinkled with a flux to melt surface oxides and given a concave shape so that surface contamination can be squeezed out of the joint as the surfaces are pounded together; otherwise the surface contamination would be trapped in the joint and would weaken the weld. In solid-state welding processes surface oxides or other contamination are typically squeezed out of the joint in "flash."

  4. Method for enhanced control of welding processes

    Science.gov (United States)

    Sheaffer, Donald A.; Renzi, Ronald F.; Tung, David M.; Schroder, Kevin

    2000-01-01

    Method and system for producing high quality welds in welding processes, in general, and gas tungsten arc (GTA) welding, in particular by controlling weld penetration. Light emitted from a weld pool is collected from the backside of a workpiece by optical means during welding and transmitted to a digital video camera for further processing, after the emitted light is first passed through a short wavelength pass filter to remove infrared radiation. By filtering out the infrared component of the light emitted from the backside weld pool image, the present invention provides for the accurate determination of the weld pool boundary. Data from the digital camera is fed to an imaging board which focuses on a 100.times.100 pixel portion of the image. The board performs a thresholding operation and provides this information to a digital signal processor to compute the backside weld pool dimensions and area. This information is used by a control system, in a dynamic feedback mode, to automatically adjust appropriate parameters of a welding system, such as the welding current, to control weld penetration and thus, create a uniform weld bead and high quality weld.

  5. 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...

  6. Laser Welding of Ship Steel

    National Research Council Canada - National Science Library

    Brayton, W. C; Banas, C. M; Peters, G. T

    1979-01-01

    ... joint cleanliness and fitup conditions. In the current program, welds were formed between surfaces with nonperfect fitup, between plasma-cut surfaces, between surfaces deliberately mismatched to provide a varging joint gap and under out...

  7. 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...

  8. Welding development for LMFBR applications

    International Nuclear Information System (INIS)

    Slaughter, G.M.; Edmonds, D.P.; Goodwin, G.M.; King, J.F.; Moorhead, A.J.

    1976-01-01

    High-quality welds with suitable properties for long-time elevated-temperature nuclear service are among the most critical needs in today's welding technology. Safe, reliable, and economic generation of future power depends on welded construction in systems such as Liquid Metal Fast Breeder Reactors (LMFBRs). Rapid thermal transients in LMFBR systems at coolant temperatures around 590 to 650 0 C (1000 to 1200 0 F) could cause creep and creep-fatigue damage that is not encountered in lower temperature reactor systems. The undesirable consequences of interaction between the two working fluids - sodium and steam - in the steam generators are also of major concern. Thus sound welds that have excellent reliability over a 30-year service life are essential. Several programs are actively underway at ORNL to satisfy this critical need and selected portions of three of these programs are discussed briefly

  9. 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.

  10. Ship construction and welding

    CERN Document Server

    Mandal, Nisith R

    2017-01-01

    This book addresses various aspects of ship construction, from ship types and construction materials, to welding technologies and accuracy control. The contents of the book are logically organized and divided into twenty-one chapters. The book covers structural arrangement with longitudinal and transverse framing systems based on the service load, and explains basic structural elements like hatch side girders, hatch end beams, stringers, etc. along with structural subassemblies like floors, bulkheads, inner bottom, decks and shells. It presents in detail double bottom construction, wing tanks & duct keels, fore & aft end structures, etc., together with necessary illustrations. The midship sections of various ship types are introduced, together with structural continuity and alignment in ship structures. With regard to construction materials, the book discusses steel, aluminum alloys and fiber reinforced composites. Various methods of steel material preparation are discussed, and plate cutting and form...

  11. 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.

  12. Effects of post weld heat treatment and weld overlay on the residual stress and mechanical properties in dissimilar metal weld

    International Nuclear Information System (INIS)

    Campos, Wagner R.C.; Ribeiro, Vladimir S.; Vilela, Alisson H.F.; Almeida, Camila R.O.; Rabello, Emerson G.

    2017-01-01

    The object of this work is a dissimilar metal weld (DMW) pipe joint between carbon steel (A-106 Gr B) and stainless steel (A-312 TP316L) pipes and filler metals of Nickel alloy (82/182), which find wide application in the field of chemical, oil, petroleum industries, fossil fuel and nuclear power plant. A lot of the failures that have occurred in dissimilar metal welded are affected greatly by residual stresses. Residual stress is often a cause of premature failure of critical components under normal operation of welded components. Several methods have been tested and developed for removing the tensile residual stresses. The aim of the methods is to reduce the tensile stress state or to create compressive stresses at a predefined area, such as the inner surface of a welded pipe joint. Post weld heat treatment (PWHT) and weld overlay (WOL) are two of the residual stress mitigation methods which reduce the tensile residual stress, create compressive stresses and arrest crack initiation and crack growth. The technique used to substantially minimized or eliminated this failure development in the root weld is the post weld heat treatments (stress relief heat treatment) or the weld overlay. In this work was studied the effectiveness in reducing internal residual stress in dissimilar metal welded pipe joints subjected to post weld heat treatment and weld overlay, measurement by hole-drilling strain-gage method of stress relaxation. Also held was mechanical characterization of the welded pipe joint itself. (author)

  13. Influence of Welding Process and Post Weld Heat Treatment on Microstructure and Pitting Corrosion Behavior of Dissimilar Aluminium Alloy Welds

    Science.gov (United States)

    Venkata Ramana, V. S. N.; Mohammed, Raffi; Madhusudhan Reddy, G.; Srinivasa Rao, K.

    2018-03-01

    Welding of dissimilar Aluminum alloy welds is becoming important in aerospace, shipbuilding and defence applications. In the present work, an attempt has been made to weld dissimilar aluminium alloys using conventional gas tungsten arc welding (GTAW) and friction stir welding (FSW) processes. An attempt was also made to study the effect of post weld heat treatment (T4 condition) on microstructure and pitting corrosion behaviour of these welds. Results of the present investigation established the differences in microstructures of the base metals in T4 condition and in annealed conditions. It is evident that the thickness of the PMZ is relatively more on AA2014 side than that of AA6061 side. In FS welds, lamellar like shear bands are well noticed on the top of the stir zone. The concentration profile of dissimilar friction stir weld in T4 condition revealed that no diffusion has taken place at the interface. Poor Hardness is observed in all regions of FS welds compared to that of GTA welds. Pitting corrosion resistance of the dissimilar FS welds in all regions was improved by post weld heat treatment.

  14. Effects of post weld heat treatment and weld overlay on the residual stress and mechanical properties in dissimilar metal weld

    Energy Technology Data Exchange (ETDEWEB)

    Campos, Wagner R.C.; Ribeiro, Vladimir S.; Vilela, Alisson H.F.; Almeida, Camila R.O.; Rabello, Emerson G., E-mail: wrcc@cdtn.br, E-mail: camilarezende.cr@gmail.com, E-mail: egr@cdtn.br, E-mail: vladimirsoler@hotmail.com, E-mail: ahfv02@outlook.com [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    The object of this work is a dissimilar metal weld (DMW) pipe joint between carbon steel (A-106 Gr B) and stainless steel (A-312 TP316L) pipes and filler metals of Nickel alloy (82/182), which find wide application in the field of chemical, oil, petroleum industries, fossil fuel and nuclear power plant. A lot of the failures that have occurred in dissimilar metal welded are affected greatly by residual stresses. Residual stress is often a cause of premature failure of critical components under normal operation of welded components. Several methods have been tested and developed for removing the tensile residual stresses. The aim of the methods is to reduce the tensile stress state or to create compressive stresses at a predefined area, such as the inner surface of a welded pipe joint. Post weld heat treatment (PWHT) and weld overlay (WOL) are two of the residual stress mitigation methods which reduce the tensile residual stress, create compressive stresses and arrest crack initiation and crack growth. The technique used to substantially minimized or eliminated this failure development in the root weld is the post weld heat treatments (stress relief heat treatment) or the weld overlay. In this work was studied the effectiveness in reducing internal residual stress in dissimilar metal welded pipe joints subjected to post weld heat treatment and weld overlay, measurement by hole-drilling strain-gage method of stress relaxation. Also held was mechanical characterization of the welded pipe joint itself. (author)

  15. Nuclear fuel rod end plug weld inspection

    International Nuclear Information System (INIS)

    Parker, M. A.; Patrick, S. S.; Rice, G. F.

    1985-01-01

    Apparatus and method for testing TIG (tungsten inert gas) welds of end plugs on a sealed nuclear reactor fuel rod. An X-ray fluorescent spectrograph testing unit detects tungsten inclusion weld defects in the top end plug's seal weld. Separate ultrasonic weld inspection system testing units test the top end plug's seal and girth welds and test the bottom end plug's girth weld for penetration, porosity and wall thinning defects. The nuclear fuel rod is automatically moved into and out from each testing unit and is automatically transported between the testing units by rod handling devices. A controller supervises the operation of the testing units and the rod handling devices

  16. Inductive energy storage commutator

    International Nuclear Information System (INIS)

    Gavrilov, I.M.

    1987-01-01

    An inductive energy storage commutator is described. The value of commutated current is up to 800 A, the voltage amplitude in the load is up to 50 kV, the working frequency is equal to 1-50 Hz, the commutated power is up to 40 MW. The commutating device comprises of the first stage commutator having two in-series connected modules of the BTSV - 800/235 high-voltage thyristor unit, the second stage commutator containing three GMI-43A parallel connected powerful pulsed triodes, a commutating capacitor, an induction coil, two supplementary high-voltage thyristor keys (20 in-series connected thyristors T2-300 (13 class)), load, control pulse shapers, thyristor keys, power supply

  17. Vibration stress relief treatment in welded samples of ST-3 steel

    International Nuclear Information System (INIS)

    Suarez, J.C.; Fernandez, L.M.; Echevarria, J.F.; Estevez, A.; Perez, A.; Aragon, B.

    1996-01-01

    The presented work is aimed to find the optimal vibration frequency and treatment duration for ST-3 steel welded test pieces. In the experiment transversal stresses were not virtually relieved by the application of vibrations at the three natural frecuencies. With regard to the optimal frequency for our system, the firths natural frequency appears to be most effective one, wherewith a maximum 35-70 % longitudinal stress relief was obtained. The influence of the propagation direction (transversal or longitudinal) of vibrations on stress relief in a welded joint was confirmed

  18. Welding of Thin Steel Plates by Hybrid Welding Process Combined TIG Arc with YAG Laser

    Science.gov (United States)

    Kim, Taewon; Suga, Yasuo; Koike, Takashi

    TIG arc welding and laser welding are used widely in the world. However, these welding processes have some advantages and problems respectively. In order to improve problems and make use of advantages of the arc welding and the laser welding processes, hybrid welding process combined the TIG arc with the YAG laser was studied. Especially, the suitable welding conditions for thin steel plate welding were investigated to obtain sound weld with beautiful surface and back beads but without weld defects. As a result, it was confirmed that the shot position of the laser beam is very important to obtain sound welds in hybrid welding. Therefore, a new intelligent system to monitor the welding area using vision sensor is constructed. Furthermore, control system to shot the laser beam to a selected position in molten pool, which is formed by TIG arc, is constructed. As a result of welding experiments using these systems, it is confirmed that the hybrid welding process and the control system are effective on the stable welding of thin stainless steel plates.

  19. Automatic arc welding of propulsion system tubing in close proximity to sensitive electronic devices

    Science.gov (United States)

    Lumsden, J. M.; Whittlesey, A. C.

    1981-01-01

    The planned final assembly of the Galileo spacecraft propulsion system tubing, which involves welding in close proximity to sensitive electronics, raised significant concerns about the effects of electromagnetic coupling of weld energy on CMOS and other sensitive integrated circuits. A test program was established to assess the potential of an orbital arc welder and an RF-induction brazing machine to damage sensitive electronic equipment. Test parameters were varied to assess the effectiveness of typical transient suppression practices such as grounding, bonding, and shielding. A technique was developed to calibrate the hazard levels at the victim-circuit location; this technique is described along with the results and conclusions of the test program.

  20. Nondestructive Online Detection of Welding Defects in Track Crane Boom Using Acoustic Emission Technique

    Directory of Open Access Journals (Sweden)

    Yong Tao

    2014-04-01

    Full Text Available Nondestructive detection of structural component of track crane is a difficult and costly problem. In the present study, acoustic emission (AE was used to detect two kinds of typical welding defects, that is, welding porosity and incomplete penetration, in the truck crane boom. Firstly, a subsidiary test specimen with special preset welding defect was designed and added on the boom surface with the aid of steel plates to get the synchronous deformation of the main boom. Then, the AE feature information of the welding defect could be got without influencing normal operation of equipment. As a result, the rudimentary location analysis can be attained using the linear location method and the two kinds of welding defects can be distinguished clearly using AE characteristic parameters such as amplitude and centroid frequency. Also, through the comparison of two loading processes, we concluded that the signal produced during the first loading process was mainly caused by plastic deformation damage and during the second loading process the stress release and structure friction between sections in welding area are the main acoustic emission sources. Thus, the AE is an available tool for nondestructive online detection of latent welding defects of structural component of track crane.

  1. Spot Welding of 6061 Aluminum Alloy by Friction Stir Spot Welding Process

    Directory of Open Access Journals (Sweden)

    M. A. Tashkandi

    2017-06-01

    Full Text Available This study was focused on the effect of welding parameters on the lap-shear fracture load of the welded joints prepared by friction stir spot welding. Four different weld parameters were analyzed: rotational speed, dwell time, pin length and shoulder size of the welding tool. It was found that the lap-shear fracture load increases with an increase of the welding parameters to a limited value and decreases with further increase. The strong welded joints failed under nugget-pull out fracture.

  2. Mechanical and electrochemical characteristics with welding materials in robotic MIG welding of dissimilar Al alloys

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seong Jong; Han, Min Su; Woo, Yong Bin [Mokpo Maritime Univ., Mokpo (Korea, Republic of)

    2013-05-15

    In this study, mechanical and electrochemical characteristics with welding material in MIG welded with ROBOT for dissimilar Al alloys were investigated using various experiment methods. The MIG welding by ROBOT with ER5183 and ER5556 for the 5456-H116 and 6061-T6 Al alloy were carried out. The hardness of welding zone was lower than that of base metal. In electrochemical experiment, ER5183 welding material presented excellent characteristics. The yield strength and maximum tensile strength in welding with welding material of ER5183 presented lower value than those of ER5556. The elongation and time-to-fracture showed the opposite results.

  3. Effect of Multi-repair Welding on Fatigue Performance of Aluminum Alloy Profile Welded Joint

    Science.gov (United States)

    Diao, You-De; Shi, Chun-Yuan; Tian, Hong-Lei

    2016-05-01

    Aluminum alloy profile has been widely used in the manufacture of the rail vehicles. But it's necessary for the repair welding of the welded joints to be conducted because some defects exist in the weld such as porosity, inclusions and incomplete penetrations in the welding processes. In this paper, the influence of the multi-repair welding of 6005A aluminum alloy profile butt welded joints on the fatigue performance are investigated based on the results of fatigue tests. The parameters of curves and the fatigue strength of the welded joints are calculated, and Goodman fatigue limit diagram is also obtained. The results show that fatigue strength of aluminum alloy profile butt welded joints, in condition of 107 cycle life, meet the standard requirement for the as-welded, repair welded state one time or two times respectively.

  4. Bringing Pulsed Laser Welding into Production

    DEFF Research Database (Denmark)

    Olsen, Flemmming Ove

    1996-01-01

    performed and is currently in progress in collaboration with a major Danish company, who currently is applying laser welding in several production lines. Furthermore some case stories from development work on laser welding for industri-al production will be described. One case story describes a current...... production of hermetic weld seams produced on radiator thermostats applying pulsed laser welding. This application has now been running in several years. 2 laser systems are currently welding each serving two welding stations. Another case story is describing a high precision assembly technique of a product......-nationally the group is mostly known for its contri-butions to the development of the laser cutting process, but further it has been active within laser welding, both in assisting industry in bringing laser welding into production in several cases and in performing fundamental R & D. In this paper some research...

  5. Polyimide weld bonding for titanium alloy joints

    Science.gov (United States)

    Vaughan, R. W.; Kurland, R. M.

    1974-01-01

    Two weld bonding processes were developed for joining titanium alloy; one process utilizes a weld-through technique and the other a capillary-flow technique. The adhesive used for the weld-through process is similar to the P4/A5F system. A new polyimide laminating resin, BFBI/BMPM, was used in the capillary-flow process. Static property information was generated for weld-bonded joints over the temperature range of 219 K (-65 F) to 561 K (+550 F) and fatigue strength information was generated at room temperature. Significant improvement in fatigue strength was demonstrated for weld-bonded joints over spot-welded joints. A demonstration was made of the applicability of the weld-through weld-bonding process for fabricating stringer stiffened skin panels.

  6. 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.

  7. Development of fully automatic pipe welding system

    International Nuclear Information System (INIS)

    Tanioka, Shin-ichi; Nakano, Mitsuhiro; Tejima, Akio; Yamada, Minoru; Saito, Tatsuo; Saito, Yoshiyuki; Abe, Rikio

    1985-01-01

    We have succeeded in developing a fully automatic TIG welding system; namely CAPTIG that enables unmanned welding operations from the initial layer to the final finishing layer continuously. This welding system is designed for continuous, multilayered welding of thick and large diameter fixed pipes of nuclear power plants and large-size boiler plants where high-quality welding is demanded. In the tests conducted with this welding system, several hours of continuous unmanned welding corroborated that excellent beads are formed, good results are obtained in radiographic inspection and that quality welding is possible most reliably. This system incorporates a microcomputer for fully automatic controls by which it features a seam tracking function, wire feed position automatic control function, a self-checking function for inter-pass temperature, cooling water temperature and wire reserve. (author)

  8. Defect rates in butt welded steel pipes

    International Nuclear Information System (INIS)

    Guille-Stevens, D.; Silcock, P.

    1980-01-01

    As the primary circuit of CANDU reactors consists largely of pipe, the reliability of pipe welds is of interest to reactor designers. A project involving 64 000 manual and semi-automatic pipe welds was inspected to the requirements of ANSI B31.3. Records of 6 000 carbon steel and 1 900 alloy steel butt welds ranging from 50 to 400 mm were inspected by radiography and ultrasonics, and analysed. No correlation between defects and number of weld passes was observed. However, small pipes exhibited a higher defect rate, per weld length and per weld volume, than did large pipes. Porosity was the major cause of defects (60 per cent) followed by root defects (27 per cent); only one crack was recorded. The results show that small (50 mm) pipe welds have the highest defect rate; however, the low overall rate shows that high standards can be maintained over many thousand welds [af

  9. Physical bases for diffusion welding processes optimization

    International Nuclear Information System (INIS)

    Bulygina, S.M.; Berber, N.N.; Mukhambetov, D.G.

    1999-01-01

    One of wide-spread method of different materials joint is diffusion welding. It has being brought off at the expense of mutual diffusion of atoms of contacting surfaces under long-duration curing at its heating and compression. Welding regime in dependence from properties of welding details is defining of three parameters: temperature, pressure, time. Problem of diffusion welding optimization concludes in determination less values of these parameters, complying with requirements for quality of welded joint. In the work experiments on diffusion welding for calculated temperature and for given surface's roughness were carried out. Tests conduct on samples of iron and iron-nickel alloy with size 1·1·1 cm 3 . Optimal regime of diffusion welding of examined samples in vacuum is defined. It includes compression of welding samples, heating, isothermal holding at temperature 650 deg C during 0.5 h and affords the required homogeneity of joint

  10. 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 curves revealing the maximum load and the elongation at break. Welding and strength testing is simulated by SORPAS® 3D, which allows the two processes to be prepared in a combined simulation, such that the simulated welding properties are naturally applied to the simulation of strength testing. Besides...... the size and shape of the weld nugget, these properties include the new strength of the material in the weld and the heat affected zone based on the predicted hardness resulting from microstructural phase changes simulated during cooling of the weld before strength testing. Comparisons between overall...

  11. Interpretation of aluminum-alloy weld radiography

    Science.gov (United States)

    Duren, P. C.; Risch, E. R.

    1971-01-01

    Report proposes radiographic terminology standardization which allows scientific interpretation of radiographic films to replace dependence on individual judgement and experience. Report includes over 50 photographic pages where radiographs of aluminum welds with defects are compared with prepared weld sections photomacrographs.

  12. Laser-GMA Hybrid Pipe Welding System

    National Research Council Canada - National Science Library

    Reutzel, Edward W; Kern, Ludwig; Sullivan, Michael J; Tressler, Jay F; Avalos, Juan

    2007-01-01

    The combination of laser welding with conventional gas metal arc welding technology offers substantial increases in production rate of joining pipe through single-pass joining compared to multi-pass...

  13. Recent developments in underwater repair welding

    International Nuclear Information System (INIS)

    Offer, H.P.; Chapman, T.L.; Willis, E.R.; Maslakowski, J.; Van Diemen, P.; Smith, B.W.

    2001-01-01

    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)

  14. Pressure vessel integrity and weld inspection procedure

    International Nuclear Information System (INIS)

    Solomon, K.A.; Okrent, D.; Kastenberg, W.E.

    1975-01-01

    The primary objective of this paper is to develop a simple methodology which, when coupled with existing observations on pressure vessel behavior, provides an inter-relation between pressure vessel integrity, and the parameters of the in-service inspection program, including inspection sample size, frequency and efficiency. A modified Markov process is employed and a computer code was written to obtain numerical results. The Markov process mathematically describes the following physical events. In a nuclear reactor pressure vessel weld, some defects may exist prior to the zeroth inspection (i.e., prior to vessel operation). During the zeroth inspection and repair processes, some of these defects are removed. During the first cycle of vessel operation, the existing defects may grow and some new defects may be generated. Those defects that are found at the first (and succeeding) inspection interval and warrant repair, are repaired. The above process continues through several operating cycles to the end of vessel life. During any inspection, only a portion of the welds may be inspected, and with less than perfect efficiency

  15. Frequency Characteristics of Geomagnetic Induction Anomalies in ...

    Indian Academy of Sciences (India)

    19

    Res., 98, 15967–15985. Gombos A. M et al 1995 The tectonic evolution of western India and its impacts on hydrocarbon occurrences; on overview; Sediment.Geol.,96, 119-129. Ingham M. R., Bhingam D. K. and Gough D.I 1983 Magnetovariational study of a geothermal anomaly; Geophys. J. R. Astron. Soc., 72, 597-618.

  16. Frequency characteristics of geomagnetic induction anomalies in ...

    Indian Academy of Sciences (India)

    Permanent link: https://www.ias.ac.in/article/fulltext/jess/126/07/0101. Keywords. Magnetovariational studies; Saurashtra; rifting; magmatic underplating; transient thermal effects; Reunion hotspot. Abstract. Magnetovariational studies were carried out along four different EW profiles in Saurashtra region in different phases, ...

  17. Frequency characteristics of geomagnetic induction anomalies in ...

    Indian Academy of Sciences (India)

    P V Vijaya Kumar

    2017-10-07

    Oct 7, 2017 ... The general stratigraphy of the peninsula, bounded between Precambrian basement at bot- ... JP) consisting of thin sediments. Different station codes used are shown in figure 1(d). ... depression and (d) various station codes used in the present work is shown. 3. Different geophysical studies in. Saurashtra ...

  18. Processing Welding Images For Robot Control

    Science.gov (United States)

    Richardson, Richard W.

    1988-01-01

    Image data from two distinct windows used to locate weld features. Analyzer part of vision system described in companion article, "Image Control in Automatic Welding Vision System" (MFS-26035). Horizontal video lines define windows for viewing unwelded joint and weld pool. Data from picture elements outside windows not processed. Widely-separated local features carry no significance, but closely spaced features indicate welding feature. Image processor assigns confidence level to group of local features according to spacing and pattern.

  19. Stereoscopic Video Weld-Seam Tracker

    Science.gov (United States)

    Kennedy, Larry Z.

    1991-01-01

    Stereoscopic video camera and laser illuminator operates in conjunction with image-data-processing computer to locate weld seam and to map surface features in vicinity of seam. Intended to track seams to guide placement of welding torch in automatic welding system and to yield information on qualities of welds. More sensitive than prior optical seam trackers and suitable for use in production environment. Tracks nearly invisible gap between butted machined edges of two plates.

  20. Welding data adquisition based on FPGA

    OpenAIRE

    Millán Vázquez de la Torre, Rafael Luis; Quero Reboul, José Manuel; García Franquelo, Leopoldo

    1997-01-01

    This paper presents the use of FPGA in data acquisition and digital preprocessing of the electric current signal of resistance welding stations. This work demonstrates that electric current has enough information to classify this kind of welds in mass production industries. Parameters extracted with the FPGA excite a classifier that accept o reject the welding junction. This system has been developed using a neural classifier and installed in a welding station of General Motors in Cádiz (Spai...

  1. Structural degradation of heterogeneous welded joints

    OpenAIRE

    Eva Schmidová; Petr Hanus

    2012-01-01

    Developing the techniques of welding materials with higher dynamic strength onto the rolling surfaces of rails is one of the options for increasing their operational endurance. The subject of this paper is an analyses of heterogeneous weld interfaces experimentally manufactured by welding medium-carbon austenitic steels onto high-carbon unalloyed pearlitic steels. The analyses focus on examinations of the marginal mixing of the materials at the weld interface and the circumstances under which...

  2. Microscopic Analysis of Welded Dental Alloys

    OpenAIRE

    S. Porojan; L. Sandu; F. Topalâ

    2011-01-01

    Microplasma welding is a less expensive alternative to laser welding in dental technology. The aim of the study was to highlight discontinuities present in the microplasma welded joints of dental base metal alloys by visual analysis. Five base metal alloys designated for fixed prostheses manufacture were selected for the experiments. Using these plates, preliminary tests were conducted by microplasma welding in butt joint configuration, without filler material, bilaterall...

  3. Magnetic Field Measurement of induction Hobs

    OpenAIRE

    森, 秀樹||モリ, ヒデキ||Mori, Hideki; 松井, 景樹||マツイ, ケイジュ||Matsui, Keiju; 山本, 勇||ヤマモト, イサム||Yamamoto, Isamu

    2004-01-01

    Recently domestic induction hobs have rapidly come into wide use in Japan. When cooking a strong high frequency magnetic field is generated in the area of induction hob. However, there are few reports of the measurement of the magnetic field during actual cooking. The magnetic field resulting from various working conditions of several types of induction hobs are reported here. Measurements of the magnetic field due to differences in various types of converter, the size and materials of the co...

  4. Corrosion Behavior of Arc Weld and Friction Stir Weld in Al 6061-T6 Alloys

    International Nuclear Information System (INIS)

    Yoon, Byoung Hyun; Kim, Heung Ju; Chang, Woong Seong; Kweon, Young Gak

    2006-01-01

    For the evaluation of corrosion resistance of Al 6061-T6 Alloy, Tafel method and immersion test was performed with Friction Stir Weld(FSW) and Gas Metal Arc Weld(GMAW). The Tafel and immersion test results indicated that GMA weld was severely attacked compared with those of friction stir weld. It may be mainly due to the galvanic corrosion mechanism act on the GMA weld

  5. 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.

  6. 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 that...

  7. 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 be...

  8. 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 be...

  9. 49 CFR 179.11 - Welding certification.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Welding certification. 179.11 Section 179.11 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY... Design Requirements § 179.11 Welding certification. (a) Welding procedures, welders and fabricators shall...

  10. 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 the...

  11. 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 temperature...

  12. 30 CFR 75.1729 - Welding operations.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Welding operations. 75.1729 Section 75.1729 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Miscellaneous § 75.1729 Welding operations. Welding...

  13. 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) Radioscopy...

  14. 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. [Amdt. 179-32, 48 FR 27708...

  15. Orbital Welding Head Held By Robot

    Science.gov (United States)

    Gangl, Kenneth J.; Graham, Benny F.; Nesmith, Malcolm F.; Mcferrin, David C.

    1992-01-01

    Orbital welding head positioned by robot controls motion and voltage of arc-welding torch mounted in head. New head encircles part at torch end, and held and manipulated by robot arm at opposite end. Entire welding operation automated. Useful for operations in hazardous environments.

  16. Simulating Welding-Robot Trajectories For Previewing

    Science.gov (United States)

    Levitt, Maureen L.; Sliwinski, Karen E.

    1992-01-01

    New method devised for generating welding-tool paths; parts of off-line-programmed test trajectories of computer-controlled welding robot. Reduces time necessary to set up simulation of welding process and eliminates some errors by reducing amount of repetition. Provides visual feedback similar to graphical simulation used in off-line-programming process after development of model.

  17. New process for weld metal reliability

    International Nuclear Information System (INIS)

    Hebel, A.G.

    1985-01-01

    The industry-wide nature of weld cracking alerts one to the possibility that there is a fundamental law being overlooked. And in overlooking this law, industry is unable to counteract it. That law mandates that restraint during welding causes internal stress; internal stress causes weld metal to crack. Component restraint during welding, according to the welding standard, is the major cause of weld metal failures. When the metal working industry accepts this fact and begins to counter the effects of restraint, the number of weld failures experienced fall dramatically. Bonal Technologies, inc., of Detroit, has developed the first consistently effective non-thermal process to relieve stress caused by restraint during welding. Bonal's patented Mets-Lax sub-resonant stress relief acts as a restraint neutralizer when used during welding. Meta-Lax weld conditioning produces a finer more uniform weld grain structure. A finer, more uniform grain structure is a clear metallurgical indication of improved mechanical weld properties. Other benefits like less internal stress, and less warpage are also achieved

  18. Calibration Check For Programmed Welding Robot

    Science.gov (United States)

    Sliwinski, Karen E.; Anderson, Ronald R.; Osterloh, Mark R.

    1992-01-01

    Preweld calibration check helps to ensure welding torch on computer-controlled welding robot mounted properly, right gas cup selected, and length of extension of electrode adjusted correctly. Performed by operator just before dry run for each set of parts welded. Procedure takes 2 to 3 minutes and enables correction of errors before parts or equipment damaged.

  19. 29 CFR 1910.255 - Resistance welding.

    Science.gov (United States)

    2010-07-01

    ... point of operation, shall be effectively guarded by the use of a device such as an electronic eye safety..., the secondary of all welding transformers used in multispot, projection and seam welding machines shall be grounded. This may be done by permanently grounding one side of the welding secondary current...

  20. Technology of welding aluminum alloys-III

    Science.gov (United States)

    Harrison, J. R.; Kor, L. J.; Oleksiak, C. E.

    1978-01-01

    Control of porosity in weld beads was major objective in development of aluminum welding program. Porosity, most difficult defect to control, is caused by hydrogen gas unable to escape during solidification. Hard tooling allows hotter bead than free-fall tooling so hydrogen bubbles can boil out instead of forming pores. Welding position, moisture, and cleanliness are other important factors in control of porosity.

  1. Fracture toughness of stainless steel welds

    International Nuclear Information System (INIS)

    Mills, W.J.

    1985-11-01

    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

  2. Defects detection on the welded reinforcing steel with self-shielded wires by vibration tests

    Directory of Open Access Journals (Sweden)

    Crâştiu Ion

    2017-01-01

    Full Text Available The aim of this paper is the development and validation of a vibroacustic technique to welding defects detection, especially for welded reinforcing structures. In welded structures subjected to dynamic cyclic loads may appear and propagate fatigue cracks due to local structural damage. These cracks may initiate due to the technological parameters used in welding process, or due to environmental operating conditions. By the means of Finite Element Method (FEM, the natural frequencies and shape modes of more welded steel specimens are determined. The analysis is carried out in undamaged condition as well as damaged one, after artificially induced damages. The experimental measurement of the vibroacustic response is carried out by using a condenser microphone, which is suitable for high-fidelity acoustic measurements in the frequency range of 20 – 20.000 Hz. The vibration responses of the welded specimens, in free-free conditions, are carried out using algorithms based on Fast Fourier Transform (FFT, and Prony's series. The results are compared to modal parameters estimated using FE Analysis.

  3. 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.

  4. 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.

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

    International Nuclear Information System (INIS)

    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

  6. Microstructure modeling in weld metal

    International Nuclear Information System (INIS)

    David, S.A.; Babu, S.S.

    1995-01-01

    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

  7. Stability evaluation of short-circuiting gas metal arc welding based on ensemble empirical mode decomposition

    Science.gov (United States)

    Huang, Yong; Wang, Kehong; Zhou, Zhilan; Zhou, Xiaoxiao; Fang, Jimi

    2017-03-01

    The arc of gas metal arc welding (GMAW) contains abundant information about its stability and droplet transition, which can be effectively characterized by extracting the arc electrical signals. In this study, ensemble empirical mode decomposition (EEMD) was used to evaluate the stability of electrical current signals. The welding electrical signals were first decomposed by EEMD, and then transformed to a Hilbert-Huang spectrum and a marginal spectrum. The marginal spectrum is an approximate distribution of amplitude with frequency of signals, and can be described by a marginal index. Analysis of various welding process parameters showed that the marginal index of current signals increased when the welding process was more stable, and vice versa. Thus EEMD combined with the marginal index can effectively uncover the stability and droplet transition of GMAW.

  8. Percussive arc welding apparatus

    Science.gov (United States)

    Hollar, Jr., Donald L.

    2002-01-01

    A percussive arc welding apparatus includes a generally cylindrical actuator body having front and rear end portions and defining an internal recess. The front end of the body includes an opening. A solenoid assembly is provided in the rear end portion in the internal recess of the body, and an actuator shaft assembly is provided in the front end portion in the internal recess of the actuator body. The actuator shaft assembly includes a generally cylindrical actuator block having first and second end portions, and an actuator shaft having a front end extending through the opening in the actuator body, and the rear end connected to the first end portion of the actuator block. The second end portion of the actuator block is in operational engagement with the solenoid shaft by a non-rigid connection to reduce the adverse rebound effects of the actuator shaft. A generally transversely extending pin is rigidly secured to the rear end of the shaft. One end of the pin is received in a slot in the nose housing sleeve to prevent rotation of the actuator shaft during operation of the apparatus.

  9. Grain structure and solidification cracking in oscillated arc welds of 5052 aluminum alloy

    Science.gov (United States)

    Kou, S.; Le, Y.

    1985-07-01

    The effect of arc oscillation on grain structure and solidification cracking in GTA welds of 5052 aluminum alloy was investigated using a four-pole magnetic arc oscillator and a modified fish-bone crack test. Two different mechanisms of crack reduction were identified: one in the low frequency range of arc oscillation and the other in the high frequency range. The former was the alteration of the orientation of columnar grains, while the latter was grain refining. Neither mechanism was operative in the intermediate frequency range and solidification cracking was severe, especially when the amplitude of arc oscillation was small. Alteration of grain orientation was obtained in welds made with transverse and circular arc oscillations, but not longitudinal arc oscillation. Grain refining, on the other hand, was achieved in welds made with all three types of arc oscillation patterns. The differences between the response of alloy 5052 to arc oscillation and that of alloy 2014 observed previously were discussed.

  10. Gelatin based on Power-gel.TM. as solders for Cr.sup.4+laser tissue welding and sealing of lung air leak and fistulas in organs

    Science.gov (United States)

    Alfano, Robert R.; Tang, Jing; Evans, Jonathan M.; Ho, Peng Pei

    2006-04-25

    Laser tissue welding can be achieved using tunable Cr.sup.4+ lasers, semiconductor lasers and fiber lasers, where the weld strength follows the absorption spectrum of water. The use of gelatin and esterified gelatin as solders in conjunction with laser inducted tissue welding impart much stronger tensile and torque strengths than albumin solders. Selected NIR wavelength from the above lasers can improve welding and avoid thermal injury to tissue when used alone or with gelatin and esterified gelatin solders. These discoveries can be used to enhance laser tissue welding of tissues such as skin, mucous, bone, blood vessel, nerve, brain, liver, pancreas, spleen, kidney, lung, bronchus, respiratory track, urinary tract, gastrointestinal tract, or gynecologic tract and as a sealant for pulmonary air leaks and fistulas such as intestinal, rectal and urinary fistulas.

  11. Laser Assisted Plasma Arc Welding

    Energy Technology Data Exchange (ETDEWEB)

    FUERSCHBACH,PHILLIP W.

    1999-10-05

    Experiments have been performed using a coaxial end-effecter to combine a focused laser beam and a plasma arc. The device employs a hollow tungsten electrode, a focusing lens, and conventional plasma arc torch nozzles to co-locate the focused beam and arc on the workpiece. Plasma arc nozzles were selected to protect the electrode from laser generated metal vapor. The project goal is to develop an improved fusion welding process that exhibits both absorption robustness and deep penetration for small scale (< 1.5 mm thickness) applications. On aluminum alloys 6061 and 6111, the hybrid process has been shown to eliminate hot cracking in the fusion zone. Fusion zone dimensions for both stainless steel and aluminum were found to be wider than characteristic laser welds, and deeper than characteristic plasma arc welds.

  12. Residual stresses in zircaloy welds

    International Nuclear Information System (INIS)

    Santisteban, J. R.; Fernandez, L; Vizcaino, P.; Banchik, A.D.; Samper, R; Martinez, R. L; Almer, J; Motta, A.T.; Colas, K.B; Kerr, M.; Daymond, M.R

    2009-01-01

    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. [es

  13. Robotic Tool Changer For Automated Welding

    Science.gov (United States)

    Gilbert, Jeffrey L.; Spencer, Carl N.

    1994-01-01

    Prototype robotic tool changer for automated welding system eliminates need for most manual tool setups and attendant problems: operates rapidly, always chooses designated tool, maneuvers tip of welding torch or other tool in correct position, and reliably connects water, gas, welding wire, high-voltage electrical signals, and ground. Also loads tools other than those for welding. Intended for use in robotic work cell producing all good parts, no rejects. In production, robot welds part, tests for flaws, and reworks as necessary before releasing it.

  14. Experimental and simulated strength of spot welds

    DEFF Research Database (Denmark)

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

    2014-01-01

    -elongation curves revealing the maximum load and the elongation at break. Welding and strength testing is simulated by SORPAS® 3D, which allows the two processes to be prepared in a combined simulation, such that the simulated welding properties are naturally applied to the simulation of strength testing. Besides...... the size and shape of the weld nugget, these properties include the new strength of the material in the weld and the heat affected zone based on the predicted hardness resulting from microstructural phase changes simulated during cooling of the weld before strength testing. Comparisons between overall...

  15. Advances in welding science - a perspective

    International Nuclear Information System (INIS)

    David, S.A.; Vitek, J.M.; Babu, S.S.; DebRoy, T.

    1995-01-01

    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

  16. Lexicographic Path Induction

    DEFF Research Database (Denmark)

    Schürmann, Carsten; Sarnat, Jeffrey

    2009-01-01

    an induction principle that combines the comfort of structural induction with the expressive strength of transfinite induction. Using lexicographic path induction, we give a consistency proof of Martin-Löf’s intuitionistic theory of inductive definitions. The consistency of Heyting arithmetic follows directly...

  17. Welding engineering manual. Vol. 4

    International Nuclear Information System (INIS)

    Ruge, J.; Thomas, K.

    1988-01-01

    Characteristics of the methods for weld calculation, based on the rules of the strength theory, are pointed out for static and dynamic stress. Among other things, the calculation rules for pressure vessels, pipeline construction and for steam boiler plants are dealt with in detail. The application of programmable pocket computers is also pointed out. Furthermore, an introduction to CAD is given which exemplarily contains a construction catalogue for welded joints. An introductory consideration of the finite element method is to solve problems of fracture mechanics. (HP) With 428 figs [de

  18. Advantages of new micro-jet welding technology on weld microstructure control

    Directory of Open Access Journals (Sweden)

    Jan PIWNIK

    2013-01-01

    Full Text Available An innovative apparatus to welding process with micro-jet cooling of the weld made it possible to carry out technological tests, which have proved theoretical considerations about this problem. This project gives real opportunities for professional development in the field of welding with controlling the parameters of weld structure. These tests have proved that the new micro-jet technology has the potential for growth. It may be great achievement of welding technology in order to increase weld metal strength. The new technology with micro-jet cooling may have many practical applications in many fields, for example such as in the transport industry or to repair damaged metal elements. The advantages of the new device over the traditional system are the ability to control the structure of the weld, the weld mechanical performance increases and improve the quality of welded joints.

  19. Closing the weld gap with laser/mig hybrid welding process

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove; Wiwe, Bjarne David

    2003-01-01

    for obtaining sound welds are identified. The welds are quality assessed according to ISO 13.919-1 and EN25817, transversal hardness measurements are made and the heat input to the workpiece is calculated. The results show that the critical gap is 0.1 mm for a laser weld alone. With hybrid welding, this can...... be increased to 0.6 mm, even at a welding speed of 3.5 m/min. The maximum welding speed with the hybrid process is comparable to laser welding alone, 4.5 m/min. The measured hardness is comparable to MIG welding, and this corresponds to a 33 percent reduction compared to laser welding alone. The heat input...

  20. Variant selection of martensites in steel welded joints with low transformation temperature weld metals

    International Nuclear Information System (INIS)

    Takahashi, Masaru; Yasuda, Hiroyuki Y.

    2013-01-01

    Highlights: ► We examined the variant selection of martensites in the weld metals. ► We also measured the residual stress developed in the butt and box welded joints. ► 24 martensite variants were randomly selected in the butt welded joint. ► High tensile residual stress in the box welded joint led to the strong variant selection. ► We discussed the rule of the variant selection focusing on the residual stress. -- Abstract: Martensitic transformation behavior in steel welded joints with low transformation temperature weld (LTTW) metal was examined focusing on the variant selection of martensites. The butt and box welded joints were prepared with LTTW metals and 980 MPa grade high strength steels. The residual stress of the welded joints, which was measured by a neutron diffraction technique, was effectively reduced by the expansion of the LTTW metals by the martensitic transformation during cooling after the welding process. In the LTTW metals, the retained austenite and martensite phases have the Kurdjumov–Sachs (K–S) orientation relationship. The variant selection of the martensites in the LTTW metals depended strongly on the type of welded joints. In the butt welded joint, 24 K–S variants were almost randomly selected while a few variants were preferentially chosen in the box welded joint. This suggests that the high residual stress developed in the box welded joint accelerated the formation of specific variants during the cooling process, in contrast to the butt welded joint with low residual stress

  1. EFFECTS OF ELECTRODE DEFORMATION OF RESISTANCE SPOT WELDING ON 304 AUSTENITIC STAINLESS STEEL WELD GEOMETRY

    Directory of Open Access Journals (Sweden)

    Nachimani Charde

    2012-12-01

    Full Text Available The resistance spot welding process is accomplished by forcing huge amounts of current flow from the upper electrode tip through the base metals to the lower electrode tip, or vice versa or in both directions. A weld joint is established between the metal sheets through fusion, resulting in a strong bond between the sheets without occupying additional space. The growth of the weld nugget (bond between sheets is therefore determined from the welding current density; sufficient time for current delivery; reasonable electrode pressing force; and the area provided for current delivery (electrode tip. The welding current and weld time control the root penetration, while the electrode pressing force and electrode tips successfully accomplish the connection during the welding process. Although the welding current and weld time cause the heat generation at the areas concerned (electrode tip area, the electrode tips’ diameter and electrode pressing forces also directly influence the welding process. In this research truncated-electrode deformation and mushrooming effects are observed, which result in the welded areas being inconsistent due to the expulsion. The copper to chromium ratio is varied from the tip to the end of the electrode whilst the welding process is repeated. The welding heat affects the electrode and the electrode itself influences the shape of the weld geometry.

  2. Experimental investigation on the weld pool formation process in plasma keyhole arc welding

    Science.gov (United States)

    Van Anh, Nguyen; Tashiro, Shinichi; Van Hanh, Bui; Tanaka, Manabu

    2018-01-01

    This paper seeks to clarify the weld pool formation process in plasma keyhole arc welding (PKAW). We adopted, for the first time, the measurement of the 3D convection inside the weld pool in PKAW by stereo synchronous imaging of tungsten tracer particles using two sets of x-ray transmission systems. The 2D convection on the weld pool surface was also measured using zirconia tracer particles. Through these measurements, the convection in a wide range of weld pools from the vicinity of the keyhole to the rear region was successfully visualized. In order to discuss the heat transport process in a weld pool, the 2D temperature distribution on the weld pool surface was also measured by two-color pyrometry. The results of the comprehensive experimental measurement indicate that the shear force due to plasma flow is found to be the dominant driving force in the weld pool formation process in PKAW. Thus, heat transport in a weld pool is considered to be governed by two large convective patterns near the keyhole: (1) eddy pairs on the surface (perpendicular to the torch axis), and (2) eddy pairs on the bulk of the weld pool (on the plane of the torch). They are formed with an equal velocity of approximately 0.35 m s‑1 and are mainly driven by shear force. Furthermore, the flow velocity of the weld pool convection becomes considerably higher than that of other welding processes, such as TIG welding and GMA welding, due to larger plasma flow velocity.

  3. Structural health monitoring of multi-spot welded joints using a lead zirconate titanate based active sensing approach

    Science.gov (United States)

    Yao, Ping; Kong, Qingzhao; Xu, Kai; Jiang, Tianyong; Huo, Lin-sheng; Song, Gangbing

    2016-01-01

    Failures of spot welded joints directly reduce the load capacity of adjacent structures. Due to their complexity and invisibility, real-time health monitoring of spot welded joints is still a challenge. In this paper, a lead zirconate titanate (PZT) based active sensing approach was proposed to monitor the structural health of multi-spot welded joints in real time. In the active sensing approach, one PZT transducer was used as an actuator to generate a guided stress wave, while another one, as a sensor, detected the wave response. Failure of a spot welded joint reduces the stress wave paths and attenuates the wave propagation energy from the actuator to the sensor. A total of four specimens made of dual phase steel with spot welds, including two specimens with 20 mm intervals of spot welded joints and two with 25 mm intervals, were designed and fabricated for this research. Under tensile tests, the spot welded joints successively failed, resulting in the PZT sensor reporting decreased received energy. The energy attenuations due to the failures of joints were clearly observed by the PZT sensor signal in both the time domain and frequency domain. In addition, a wavelet packet-based spot-weld failure indicator was developed to quantitatively evaluate the failure condition corresponding to the number of failed joints.

  4. On the non-proportionality between wheel/rail contact forces and speed during wheelset passage over specific welds

    Science.gov (United States)

    Correa, Nekane; Vadillo, Ernesto G.; Santamaria, Javier; Blanco-Lorenzo, Julio

    2018-01-01

    This study investigates the influence on the wheel-rail contact forces of the running speed and the shape and position of weld defects along the track. For this purpose, a vertical dynamic model in the space domain is used. The model is obtained from the transformation between the domains of frequency and space using a Rational Fraction Polynomials (RFP) method, which is modified with multiobjective genetic algorithms in order to improve the fitting of track receptance and to assist integration during simulations. This produces a precise model with short calculation times, which is essential to this study. The wheel-rail contact is modelled using a non-linear Hertz spring. The contact forces are studied for several types of characteristic welds. The way in which forces vary as a function of weld position and running speed is studied for each type of weld. This paper studies some of the factors that affect the maximum forces when the vehicle moves over a rail weld, such as weld geometry, parametric excitation and contact stiffness. It is found that the maximum force in the wheel-rail contact when the vehicle moves over a weld is not always proportional to the running speed. The paper explains why it is not proportional in specific welds.

  5. Validation of welded joint residual stress simulation

    International Nuclear Information System (INIS)

    Computational mechanics is being increasingly applied to predict the state of residual stress in welded joints for nuclear power plant applications. Motives for undertaking such calculations include optimising the design of welded joints and weld procedures, assessing the effectiveness of mitigation processes, providing more realistic inputs to structural integrity assessments and underwriting safety cases for operating nuclear power plant. Fusion welding processes involve intense localised heating to melt the surfaces to be joined and introduction of molten weld filler metal. A complex residual stress field develops at the weld through solidification, differential thermal contraction, cyclic thermal plasticity, phase transformation and chemical diffusion processes. The calculation of weld residual stress involves detailed non-linear analyses where many assumptions and approximations have to be made. In consequence, the accuracy and reliability of solutions can be highly variable. This paper illustrates the degree of variability that can arise in weld residual stress simulation results and summarises the new R6 guidelines which aim to improve the reliability and accuracy of computational predictions. The requirements for validating weld simulations are reviewed where residual stresses are to be used in fracture mechanics analysis. This includes a discussion of how to obtain and interpret measurements from mock-ups, benchmark weldments and published data. Benchmark weldments are described that illustrate some of the issues and show how validation of numerical prediction of weld residual stress can be achieved. Finally, plans for developing the weld modelling guidelines and associated benchmarks are outlined

  6. Zircaloy welding in OPAL reactor reflector vessel

    International Nuclear Information System (INIS)

    Ortiz, L.; Martinez, R.

    2006-01-01

    Full text: Full text: This paper describes the development of the Zircaloy 4 welding processes applied in the fabrication of the Reflector Vessel for the OPAL reactor. As an introduction, a brief description is made of the geometric design of the Reflector Vessel, which is very complex, as it has many irradiation positions, beams tubes, channels, outer connections, and reinforcements. The complexity of this component demanded different welded joints and a careful manufacturing sequence, which comprised welding, machining, heat treatments, and quality control operations. Design and fabrication of different ad-hoc devices was also required, some of which are described in the present paper. For the purposes of issuing reliable welding procedures, the joints were previously set up through tests using samples and mock-ups. Procedures and welders were qualified in accordance with the ASME Code, Section IX. The welding methods used in the fabrication were GTAW (Gas Tungsten Arc Welding) and PAW (Plasma Arc Welding), processes deemed adequate to weld these alloys, as they do not contaminate the material, for they are carried out within an inert gas atmosphere. Contrary to other welding methods commonly used for other materials, no welding fluxes or chemically-active gases are applied in these two processes. The advantages of both methods used are discussed. The welds were carried out in manual, orbital, or mechanized mode depending on the type of joint

  7. Analysis of weld solidification cracking in cast nickel aluminide alloys

    International Nuclear Information System (INIS)

    Santella, M.L.; Feng, Z.

    1995-01-01

    A study of the response of several nickel aluminide alloys to SigmaJig testing was done to examine their weld solidification cracking behavior and the effect of Zr concentration. The alloys were based on the Ni-8Al-7.7Cr-1.5Mo-0.003B wt% composition and contained Zr concentrations of 3, 4.5, and 6 wt%. Vacuum induction melted ingots with a diameter of 2.7 in and weight about 18 lb were made of each alloy, and were used to make 2 x 2 x 0.030 in specimens for the Sigmajig test. The gas tungsten arc welds were made at travel speeds of 10, 20, and 30 ipm with heat inputs of 2--2.5 kJ/in. When an arc was established before traveling onto the test specimen centerline cracking was always observed. This problem was overcome by initiating the arc directly on the specimens. Using this approach, the 3 wt% Zr alloy withstood an applied stress of 24 ksi without cracking at a welding speed of 10 ipm. This alloy cracked at 4 ksi applied at 20 ipm, and with no applied load at 30 ipm. Only limited testing was done on the remaining alloys, but the results indicate that resistance to solidification cracking increases with Zr concentration. Zirconium has limited solid solubility and segregates strongly to interdendritic regions during solidification where it forms a Ni solid solution-Ni 5 Zr eutectic. The volume fraction of the eutectic increases with Zr concentration. The solidification cracking behavior of these alloys is consistent with phenomenological theory, and is discussed in this context. The results from SigmaJig testing are analyzed using finite element modeling of the development of mechanical strains during solidification of welds. Experimental data from the test substantially agree with recent analysis results

  8. Sensor Control of Robot Arc Welding

    Science.gov (United States)

    Sias, F. R., Jr.

    1983-01-01

    The potential for using computer vision as sensory feedback for robot gas-tungsten arc welding is investigated. The basic parameters that must be controlled while directing the movement of an arc welding torch are defined. The actions of a human welder are examined to aid in determining the sensory information that would permit a robot to make reproducible high strength welds. Special constraints imposed by both robot hardware and software are considered. Several sensory modalities that would potentially improve weld quality are examined. Special emphasis is directed to the use of computer vision for controlling gas-tungsten arc welding. Vendors of available automated seam tracking arc welding systems and of computer vision systems are surveyed. An assessment is made of the state of the art and the problems that must be solved in order to apply computer vision to robot controlled arc welding on the Space Shuttle Main Engine.

  9. Experimental analysis of cut welding in aluminium

    DEFF Research Database (Denmark)

    Dorph, Pernille; De Chiffre, Leonardo; Bay, Niels

    1993-01-01

    Cut welding is a newly developed cold pressure welding process. In the present work, an experimental investigation was carried out analyzing the mechanisms involved in cut welding of a block to a strip. Experiments were carried out in technically pure aluminium. The investigation has involved...... tensile testing and metallographic investigations of the welds. The results show that this variant of cut welding is a very reproducible process giving a weld strength equal to 30-40% the strength of the parent material. The experiments have shown that the reason for this relatively low strength...... is an uneven pressure distribution along the weld due to a wave formed during sliding. Attempts to alter the material flow during sliding are presented....

  10. Development of high productivity pipeline girth welding

    International Nuclear Information System (INIS)

    Yapp, David; Liratzis, Theocharis

    2010-01-01

    The trend for increased oil and gas consumption implies a growth of long-distance pipeline installations. Welding is a critical factor in the installation of pipelines, both onshore and offshore, and the rate at which the pipeline can be laid is generally determined by the speed of welding. This has resulted in substantial developments in pipeline welding techniques. Arc welding is still the dominant process used in practice, and forge welding processes have had limited successful application to date, in spite of large investments in process development. Power beam processes have also been investigated in detail and the latest laser systems now show promise for practical application. In recent years the use of high strength steels has substantially reduced the cost of pipeline installation, with X70 and X80 being commonly used. This use of high strength pipeline produced by thermomechanical processing has also been researched. They must all meet three requirments, high productivity, satisfactory weld properties, and weld quality

  11. Advances in solar cell welding technology

    Energy Technology Data Exchange (ETDEWEB)

    Chidester, L.G.; Lott, D.R.

    1982-09-01

    In addition to developing the rigid substrate welded conventional cell panels for an earlier U.S. flight program, LMSC recently demonstrated a welded lightweight array system using both 2 x 4 and 5.9 x 5.9 cm wraparound solar cells. This weld system uses infrared sensing of weld joint temperature at the cell contact metalization interface to precisely control weld energy on each joint. Modules fabricated using this weld control system survived lowearth-orbit simulated 5-year tests (over 30,000 cycles) without joint failure. The data from these specifically configured modules, printed circuit substrate with copper interconnect and dielectric wraparound solar cells, can be used as a basis for developing weld schedules for additional cell array panel types.

  12. APPARATUS AND METHOD FOR ARC WELDING

    Science.gov (United States)

    Noland, R.A.; Stone, C.C.

    1960-05-10

    An apparatus and method are given for forming a welding arc which is rotated by a magnetic field very rapidly about an annular electrode so that a weld is produced simultaneously over all points of an annular or closed path. This invention inhibits outgassing from the jacket of a fuel slug which is being welded by adjusting the pressure throughout the welding cycle to establish a balance between the gas pressure within the jacket and that of the atmosphere surrounding the jacket. Furthermore, an improved control of the magnetic field producing rotation of the welding arc is disclosed whereby this rotation is prevented from splashing about the metal being welded as the welding arc makes it molten.

  13. A Brief Introduction to the Theory of 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 is already an important welding process for the aerospace industry, where welds of optimal quality are demanded. The structure of welds determines weld properties. The structure of friction stir welds is determined by the flow field in the weld metal in the vicinity of the weld tool. A simple kinematic model of the FSW flow field developed at Marshall Space Flight Center, which enables the basic features of FSW microstructure to be understood and related to weld process parameters and tool design, is explained.

  14. Mechanical Properties of Plug Welds after Micro-Jet Cooling

    Directory of Open Access Journals (Sweden)

    Hadryś D.

    2016-12-01

    Full Text Available New technology of micro-jet welding could be regarded as a new way to improve mechanical properties of plug welds. The main purpose of that paper was analyzing of mechanical properties of plug welds made by MIG welding method with micro-jet cooling. The main way for it was comparison of plug welds made by MIG welding method with micro-jet cooling and plug welds made by ordinary MIG welding method. It is interesting for steel because higher amount of acicular ferrite (AF in weld metal deposit (WMD is obtained in MIG welding method with micro-jet cooling in relation to ordinary MIG welding method. This article presents the influence of the cooling medium and the number of micro-jet streams on mechanical properties of the welded joint. Mechanical properties were described by force which is necessary to destroy weld joint.

  15. In-service inspection for assessment of weld degradation in SS 310S reduction retort

    International Nuclear Information System (INIS)

    Murthy, C.H.V.S.; Naik, Kalpana; Yadav, M.K.; Lakshmi, K.S.; Kapoor, Komal

    2015-01-01

    Austenitic stainless steel AISI 310S is used as the material of construction for Reduction retorts. SS 310S is selected for its ease of fabrication, corrosion and elevated temperature (around 850ÚC) properties. Matching welding consumables (E 310/ER 310) are used for welding of longitudinal and circumferential joints during fabrication of these retorts. The high temperatures applied during both welding and service, significantly affect the microstructure and properties of the weldment. During operation, these retorts are subjected to highly corrosive chloride environment in addition to high temperature. The middle zone operating temperature is 600ÚC to 700Ú C and undergoes inter granular stress corrosion attack (IGSCC) from inside and oxidation on outside surface. The bottom zone operating temperature is 800ÚC to 850ÚC and undergoes IGSCC and weld degradation. The retort is operated at an internal pressure of 5 psig and carries a tensile load of around 6 tons at 850ÚC. Hence these reduction retorts are subjected to in-service inspection (visual inspection and radiography of hot zone welds) after 40 runs and thereafter at regular frequencies to assess the healthiness of the weld joints. During In-service inspection (ISI), in retorts which were welded with ER 310 filler wire, many cracks were observed in the weld between shell and dished end. Inspection of welds during service was carried out using digital radiography by using a panoramic X-ray exposure. In order to find out the cause for the weld degradation and linear defects formation and propagation, failure analysis of the retorts was taken up. The observations in the failure analysis were correlated with the fabrication history, operating data and in-service inspection data. With this the mechanisms of weld degradation were identified and recommendations were made to improve the life of the retorts. The use of E 310 Mo welding consumables, modification of process conditions and fabrication procedures

  16. Polish Gynecological Society Recommendations for Labor Induction.

    Science.gov (United States)

    Bomba-Opoń, Dorota; Drews, Krzysztof; Huras, Hubert; Laudański, Piotr; Paszkowski, Tomasz; Wielgoś, Mirosław

    2017-01-01

    Labor induction involves artificial stimulation of childbirth before the natural, spontaneous onset of labor. It is one of the most common procedures in modern obstetrics. The frequency of labor induction has doubled in recent decades due to the development of perinatology and methods of monitoring fetal well-being in particular. Currently, one in five pregnant women and 30-40% of women delivering vaginally undergo this procedure. Reasons for induction include reduction of the perinatal mortality and morbidity of the fetus and newborn, as well as the reduction of maternal complications. However, as every medical intervention, labor induction is associated with a risk of complications.

  17. Studies on CO2-laser Hybrid-Welding of Copper

    DEFF Research Database (Denmark)

    Nielsen, Jakob Skov; Olsen, Flemming Ove; Bagger, Claus

    2005-01-01

    CO2-laser welding of copper is known to be difficult due to the high heat conductivity of the material and the high reflectivity of copper at the wavelength of the CO2-laser light. THis paper presents a study of laser welding of copper, applying laser hybrid welding. Welding was performed...... as a hybrid CO2-laser and GTAW welding process in 2 mm pure copper sheets. The purpose was to identify maximum welding speeds for the three independent welding processes, i.e. GTAW alone, laser alone and combined processes. After welding, representative welds were quality assesed according to inernational...

  18. Analysis of Factors Affecting Fractures of Rails Welded by Alumino-Thermic Welding

    OpenAIRE

    Sergejevs, D; Mihailovs, S

    2008-01-01

    On Latvian Railway, the use of the thermic welding is widespread using the ELECTRO-THERMIT Company technology. Today it is a basic method for rail joints. Experience of the operation of rails welded by the thermic welding showed that every year occur from 2 to 3 fractures of thermic joints on the main tracks between stations of Latvian Railway.Such emergence of cracks in the weld joint alongside the scores indicates of great residual stresses in the weld joints made by the thermic welding.

  19. Residual Stress Analysis of an Overlay Weld on a Repair Weld

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kang Soo; Lee, Ho Jin; Lee, Bong Sang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Jung, I. C.; Byeon, J. G.; Park, K. S. [Doosan Heavy Industries and Construction Co., Changwon (Korea, Republic of)

    2008-10-15

    In recent years, the dissimilar metal, Alloy 82/182 welds used to connect stainless steel piping and low alloy steel or carbon steel components in nuclear reactor piping system have experienced the cracking due to primary water stress corrosion(PWSCC). It is well known that one reason of the cracking is the residual stress by the weld. But, it is difficult to estimate the weld residual stress exactly due to many parameters of a welding. In this paper, the analysis of 3 FEM models is performed to estimate the weld residual stress on the dissimilar metal weld exactly.

  20. Residual stress analysis of an overlay weld on a dissimilar metal weld

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kang Soo; Lee, Ho Jin; Lee, Bong Sang (Korea Atomic Energy Research Institute, Daejeon (Korea)); Jung, I.C.; Byeon, J.G.; Park, K.S. (Doosan Heavy Industries and Construction Co., Changwon (Korea)), e-mail: kskim5@kaeri.re.kr

    2009-07-01

    In recent years, a dissimilar metal, Alloy 82/182 welds used to connect stainless steel piping and low alloy steel or carbon steel components in nuclear reactor piping system have experienced a cracking due to a primary water stress corrosion (PWSCC). It is well known that one reason for the cracking is the residual stress by the weld. But, it is difficult to estimate the weld residual stress exactly due to many parameters of a welding. In this paper, the analysis of 3 FEM models is performed to estimate the weld residual stress on a dissimilar metal weld exactly

  1. 49 CFR 192.235 - Preparation for welding.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 3 2010-10-01 2010-10-01 false Preparation for welding. 192.235 Section 192.235... BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Welding of Steel in Pipelines § 192.235 Preparation for welding. Before beginning any welding, the welding surfaces must be clean and free of any material that...

  2. General Mechanical Repair. Welding. Volume 2. Teacher's Guide.

    Science.gov (United States)

    East Texas State Univ., Commerce. Occupational Curriculum Lab.

    Five units on welding are presented in this teacher's guide. The units are the following: introduction to oxyacetylene welding, oxyacetylene welding positions and applications, use of the cutting torch, introduction to shielded metal arc welding, and welding joints and positions. Each instructional unit generally contains eight components:…

  3. Investigation on the Mechanism and Failure Mode of Laser Transmission Spot Welding Using PMMA Material for the Automotive Industry

    Science.gov (United States)

    Wang, Xiao; Liu, Baoguang; Liu, Wei; Zhong, Xuejiao; Jiang, Yingjie; Liu, Huixia

    2017-01-01

    To satisfy the need of polymer connection in lightweight automobiles, a study on laser transmission spot welding using polymethyl methacrylate (PMMA) is conducted by using an Nd:YAG pulse laser. The influence of three variables, namely peak voltages, defocusing distances and the welding type (type I (pulse frequency and the duration is 25 Hz, 0.6 s) and type II (pulse frequency and the duration is 5 Hz, 3 s)) to the welding quality was investigated. The result showed that, in the case of the same peak voltages and defocusing distances, the number of bubbles for type I was obviously more than type II. The failure mode of type I was the base plate fracture along the solder joint, and the connection strength of type I was greater than type II. The weld pool diameter:depth ratio for type I was significantly greater than type II. It could be seen that there was a certain relationship between the weld pool diameter:depth ratio and the welding strength. By the finite element simulation, the weld pool for type I was more slender than type II, which was approximately the same as the experimental results. PMID:28772383

  4. Investigation on the Mechanism and Failure Mode of Laser Transmission Spot Welding Using PMMA Material for the Automotive Industry.

    Science.gov (United States)

    Wang, Xiao; Liu, Baoguang; Liu, Wei; Zhong, Xuejiao; Jiang, Yingjie; Liu, Huixia

    2017-01-01

    To satisfy the need of polymer connection in lightweight automobiles, a study on laser transmission spot welding using polymethyl methacrylate (PMMA) is conducted by using an Nd:YAG pulse laser. The influence of three variables, namely peak voltages, defocusing distances and the welding type (type I (pulse frequency and the duration is 25 Hz, 0.6 s) and type II (pulse frequency and the duration is 5 Hz, 3 s)) to the welding quality was investigated. The result showed that, in the case of the same peak voltages and defocusing distances, the number of bubbles for type I was obviously more than type II. The failure mode of type I was the base plate fracture along the solder joint, and the connection strength of type I was greater than type II. The weld pool diameter:depth ratio for type I was significantly greater than type II. It could be seen that there was a certain relationship between the weld pool diameter:depth ratio and the welding strength. By the finite element simulation, the weld pool for type I was more slender than type II, which was approximately the same as the experimental results.

  5. Fabrication Flaw Density and Distribution in Weld Repairs

    International Nuclear Information System (INIS)

    Doctor, Steven R.

    2009-01-01

    The Pacific Northwest National Laboratory (PNNL) is developing a generalized flaw distribution for the population of nuclear reactor pressure vessels and for piping welds in the U. S. operating reactors. The purpose of the generalized flaw distribution is to predict component-specific flaw densities. The estimates of fabrication flaws are intended for use in fracture mechanics structural integrity assessments. Structural integrity assessments, such as estimating the frequency of loss-of-coolant accidents, are performed by computer codes that require, as input, accurate estimates of flaw densities. Welds from four different cancelled reactor pressure vessels and a collection of archived pipes have been studied to develop empirical estimates of fabrication flaw densities. This paper describes the fabrication flaw distribution and characterization in the repair weld metal of vessels and piping. This work indicates that large flaws occur in these repairs which are complex in composition and sometimes include cracks on the ends of the repair cavities. Parametric analysis using an exponential fit is performed on the data. Construction records where available were reviewed. It is difficult to make conclusions due to the limited number of construction records reviewed. However, the records reviewed to date show a significant change in repair frequency over the years when the components in this study were fabricated. A description of repair flaw morphology is provided with a discussion of fracture mechanics significance.

  6. Induction accelerator test module for HIF

    International Nuclear Information System (INIS)

    Faltens, A.

    1991-04-01

    An induction linac test module suitable for investigating the drive requirements and the longitudinal coupling impedance of a high-power ion induction linac has been constructed by the Heavy Ion Fusion (HIF) group at LBL. The induction linac heavy ion driver for inertial confinement fusion (ICF) as presently envisioned uses multiple parallel beams which are transported in separate focusing channels but accelerated together in the induction modules. The resulting induction modules consequently have large beam apertures-1--2 meters in diameter- and correspondingly large outside diameters. The module geometry is related to a low-frequency ''gap capacity'' and high-frequency structural resonances, which are affected by the magnetic core loading and the module pulser impedance. A description of the test module and preliminary results are presented. 3 figs

  7. Welding procedure specification for arc welding of St 52-3N steel plates with covered electrodes

    International Nuclear Information System (INIS)

    Cvetkovski, S.; Slavkov, D.; Magdeski, J.

    2003-01-01

    In this paper the results of approval welding technology for arc welding of plates made of St 52-3N steel are presented. Metal arc welding with covered electrode is used welding process. Test specimens are butt welded in different welding positions P A , P F , P C and P D . Before start welding preliminary welding procedure was prepared. After welding of test specimens non destructive and destructive testing was performed. Obtained results were compared with standard DIN 17100 which concerns to chemical composition and mechanical properties of base material. It was confirmed that in all cases mechanical properties of welded joint are higher than those of base material, so preliminary welding procedure (pWTS) can be accepted as welding procedure specification WPS for metal arc welding of St52-3N steel. (Original)

  8. Fundamentals of Welding. Teacher Edition.

    Science.gov (United States)

    Fortney, Clarence; And Others

    These instructional materials assist teachers in improving instruction on the fundamentals of welding. The following introductory information is included: use of this publication; competency profile; instructional/task analysis; related academic and workplace skills list; tools, materials, and equipment list; and 27 references. Seven units of…

  9. Projection welding for cost cutting

    International Nuclear Information System (INIS)

    Kuncz, F. Jr.

    1980-01-01

    Resistance projection welding is described pointing out the advantages, the machine requirements to be met, the suitability of various metals and/or metal combinations, the design considerations, the projection design requirements and their placement, and the limitations of this process

  10. Welding the CNGS decay tube

    CERN Multimedia

    Maximilien Brice

    2004-01-01

    3.6 km of welds were required for the 1 km long CERN Neutrinos to Gran Sasso (CNGS) decay tube, in which particles produced in the collision with a proton and a graphite target will decay into muons and muon neutrinos. Four highly skilled welders performed this delicate task.

  11. Mechanics Model of Plug Welding

    Science.gov (United States)

    Zuo, Q. K.; Nunes, A. C., Jr.

    2015-01-01

    An analytical model has been developed for the mechanics of friction plug welding. The model accounts for coupling of plastic deformation (material flow) and thermal response (plastic heating). The model predictions of the torque, energy, and pull force on the plug were compared to the data of a recent experiment, and the agreements between predictions and data are encouraging.

  12. EXPERIMENTAL RESEARCH ON ULTRASONIC WELDING

    Directory of Open Access Journals (Sweden)

    Cornelia LUCHIAN

    2012-05-01

    Full Text Available This paper presents the optimum ultrasound welding parameters of copper sheets usingstatic analysis methods results and microscopic structural analysis. Also it get the conclusion thatweld formation it’s produced after the plastic deformation process of metals because the action ofultrasonic energy in the joint area.

  13. Rapid Detection of Transition Metals in Welding Fumes Using Paper-Based Analytical Devices

    Science.gov (United States)

    Volckens, John

    2014-01-01

    Metals in particulate matter (PM) are considered a driving factor for many pathologies. Despite the hazards associated with particulate metals, personal exposures for at-risk workers are rarely assessed due to the cost and effort associated with monitoring. As a result, routine exposure assessments are performed for only a small fraction of the exposed workforce. The objective of this research was to evaluate a relatively new technology, microfluidic paper-based analytical devices (µPADs), for measuring the metals content in welding fumes. Fumes from three common welding techniques (shielded metal arc, metal inert gas, and tungsten inert gas welding) were sampled in two welding shops. Concentrations of acid-extractable Fe, Cu, Ni, and Cr were measured and independently verified using inductively coupled plasma-optical emission spectroscopy (ICP-OES). Results from the µPAD sensors agreed well with ICP-OES analysis; the two methods gave statistically similar results in >80% of the samples analyzed. Analytical costs for the µPAD technique were ~50 times lower than market-rate costs with ICP-OES. Further, the µPAD method was capable of providing same-day results (as opposed several weeks for ICP laboratory analysis). Results of this work suggest that µPAD sensors are a viable, yet inexpensive alternative to traditional analytic methods for transition metals in welding fume PM. These sensors have potential to enable substantially higher levels of hazard surveillance for a given resource cost, especially in resource-limited environments. PMID:24515892

  14. Influence of weld discontinuities on strain controlled fatigue behavior of 308 stainless steel weld metal

    International Nuclear Information System (INIS)

    Bhanu Sankara Rao, K.; Valsan, M.; Sandhya, R.; Mannan, S.L.; Rodriguez, P.

    1994-01-01

    Detailed investigations have been performed for assessing the importance of weld discontinuities in strain controlled low cycle fatigue (LCF) behavior of 308 stainless steel (SS) welds. The LCF behavior of 308 SS welds containing defects was compared with that of type 304 SS base material and 308 SS sound weld metal. Weld pads were prepared by shielded metal arc welding process. Porosity and slag inclusions were introduced deliberately into the weld metal by grossly exaggerating the conditions normally causing such defects. Total axial strain controlled LCF tests have been conducted in air at 823 K on type 304 SS base and 308 SS sound weld metal employing strain amplitudes in the range from ±0.25 to ±0.8 percent. A single strain amplitude of ±0.25 percent was used for all the tests conducted on weld samples containing defects. The results indicated that the base material undergoes cyclic hardening whereas sound and defective welds experience cyclic softening. Base metal showed higher fatigue life than sound weld metal at all strain amplitudes. The presence of porosity and slag inclusions in the weld metal led to significant reduction in life. Porosity on the specimen surface has been found to be particularly harmful and caused a reduction in life by a factor of seven relative to sound weld metal

  15. Investigate The Effect Of Welding Parameters On Mechanical Properties During The Welding Of Al-6061 Alloy

    Directory of Open Access Journals (Sweden)

    Rajendra Prasad

    2017-10-01

    Full Text Available Friction welding is a solid state welding technique which is being used in recent times to weld similar as well as dissimilar metals for getting defect free weld. Many combinations like low carbon to stainless steel austenitic to ferrite stainless steel aluminium to copper and titanium to aluminium or steel have been tried out by various solid state welding processes with quite good results. In the present work the 3 level full factorial design has been employed to investigate the effect of welding parameters on tensile strength toughness and heat generation during the welding of Al-6061 alloy. Mathematical relationships between friction welding parameters and mechanical properties like heat generation tensile strength and toughness have also been developed. An attempt has also been made to examine the fracture surfaces of test specimens using SEM. It has been found that welding speed is the most significant parameter thats affect the heat generation tensile strength and toughness. it has been found that tensile strength and toughness during welding increases with increased in welding speed while tensile strength and toughness initially increased as the welding time increases after that it decreased with increase in welding time. The difference in weight of alloying elements can be clearly seen by analyzing spectrum of elements.

  16. Welded joints integrity analysis and optimization for fiber laser welding of dissimilar materials

    Science.gov (United States)

    Ai, Yuewei; Shao, Xinyu; Jiang, Ping; Li, Peigen; Liu, Yang; Liu, Wei

    2016-11-01

    Dissimilar materials welded joints provide many advantages in power, automotive, chemical, and spacecraft industries. The weld bead integrity which is determined by process parameters plays a significant role in the welding quality during the fiber laser welding (FLW) of dissimilar materials. In this paper, an optimization method by taking the integrity of the weld bead and weld area into consideration is proposed for FLW of dissimilar materials, the low carbon steel and stainless steel. The relationships between the weld bead integrity and process parameters are developed by the genetic algorithm optimized back propagation neural network (GA-BPNN). The particle swarm optimization (PSO) algorithm is taken for optimizing the predicted outputs from GA-BPNN for the objective. Through the optimization process, the desired weld bead with good integrity and minimum weld area are obtained and the corresponding microstructure and microhardness are excellent. The mechanical properties of the optimized joints are greatly improved compared with that of the un-optimized welded joints. Moreover, the effects of significant factors are analyzed based on the statistical approach and the laser power (LP) is identified as the most significant factor on the weld bead integrity and weld area. The results indicate that the proposed method is effective for improving the reliability and stability of welded joints in the practical production.

  17. Laser welding of tailored blanks

    Directory of Open Access Journals (Sweden)

    Peças, P.

    1998-04-01

    Full Text Available Laser welding has an incrising 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 formibility. 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.

    A soldadura laser assume um papel cada vez mais importante na indústria automóvel, principalmente para a fabricação de sub-conjuntos constituídos por varias partes de chapa de diferentes espessuras (e diferentes materiais, que depois de estampados constituem um componente para integrar num veículo. Descreve-se neste artigo o trabalho de investigação de enformabilidade de chapa de ac.o de baixo carbono soldada por laser de CO2, nas espessuras de 1,25 e 0,75 mm. Apresenta-se uma descrição do comportamento das chapas soldadas por laser em diferentes testes de enformação, e a influência dos defeitos das soldaduras (desalinhamento e queda do banho-undercut no comportamento à enformação. A qualidade é avaliada pela medição da extensão limite e da extensão limite efectiva no material base e no material soldado, que serão representadas num diagrama de limite de enformabilidade.

  18. Ultrasound in arc welding: a review.

    Science.gov (United States)

    da Cunha, Tiago Vieira; Bohórquez, Carlos Enrique Niño

    2015-02-01

    During the last decade, the introduction of ultrasound techniques in arc welding with the intention of improving the operational performance and technical characteristics of the welding processes have been studied intensively. In this work is presented a broad review of the literature surrounding the utilization of this technique. Firstly, we discuss the use of traditional mechanical transducers to generate ultrasound in arc welding. Furthermore, we describe the various methods and their application in arc-welding processes. After, is presented a recent method of introducing ultrasonic energy in arc welding, which forms a potential alternative to the use of traditional mechanical type transducers. This method was originally developed in the late 1990s and is called arc with ultrasonic excitation of current. Here, the arc acts not only as a thermal source but also as an emission mechanism for ultrasound, acting directly on the weld pool. We presented and discussed various innovative concepts based on this method, which allows the introduction of ultrasonic energy in the arc welding without the need of any auxiliary device of welding. In addition, we also presented the variations of this method reported in the literature. Finally, we have described the respective effects attributed to the use of this method in the welding of different materials using various welding processes. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. A 1993 review of welding in Japan

    Science.gov (United States)

    1994-07-01

    This paper describes a prospect on Japanese welding technologies available in 1993. Amid the increasing research publications on non-ferrous metals as structural materials, publications are also increasing on steel materials as to their fracture and welding mechanics, and structural control. Studies are being made on ceramics with respect to its bonding, interface reaction mechanisms, and mechanical characteristics. The paper describes the progress and improvement in conventional technologies in welding and cutting processes. Especially active is the study on solid face welding such as pressure welding and diffusion. A considerable decrease is seen in reports on thermal spraying. The paper also introduces surface processing and hydrostatic pressure processing as new processing techniques. In the area of welding devices, practical use of arc welding robots has come to near a completion stage. Technological development and cost reduction are indispensable to transfer to visual sensing with a higher intelligence level. With respect to the performance of joints, a large number of research has been reported on welding deformation and residual stress. The paper also dwells on corrosion resistance and welding cracks. Quality assurance, inspection, and related standards are described. Details are given on application of welding to different industrial fields.

  20. ITER lip seal welding and cutting developments

    Energy Technology Data Exchange (ETDEWEB)

    Levesy, B.; Cordier, J.J.; Jokinen, T. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Kujanpää, V.; Karhu, M. [VTT Technical Research Centre of Finland (Finland); Le Barbier, R. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France); Määttä, T. [VTT Technical Research Centre of Finland (Finland); Martins, J.P.; Utin, Y. [ITER Organization, Route de Vinon sur Verdon, 13115 Saint Paul Lez Durance (France)

    2015-10-15

    Highlights: • Different TIG and Laser welding techniques are tested. • Twin spot laser welding techniques is the best. • Limited heat input gives a stable weld pool in all positions. • Penetrations is achieved. • Lip seal welding and cutting with a robotic arm is successfully performed on a representative mock-up. - Abstract: The welded lip seals form part of the torus primary vacuum boundary in between the port plugs and the vacuum vessel, and are classified as Protection Important Component. In order to refurbish the port plugs or the in-vessel components, port plugs have to be removed from the machine. The lip seal design must enable up to ten opening of the vacuum vessel during the life time operation of the ITER machine. Therefore proven, remote reliable cutting and re-welding are essential, as these operations need to be performed in the port cells in a nuclear environment, where human presence will be restricted. Moreover, the combination of size of the components to be welded (∼10 m long vacuum compatible thin welds) and the congested environment close to the core of the machine constraint the type and size of tools to be used. This paper describes the lip seal cutting and welding development programme performed at the VTT Technical Research Centre, Finland. Potential cutting and welding techniques are analyzed and compared. The development of the cutting, TIG and laser welding techniques on samples are presented. Effects of lip seal misalignments and optimization of the 2 welding processes are discussed. Finally, the manufacturing and test of the two 1.2 m × 1 m representative mock-ups are presented. The set-up and use of a robotic arm for the mock-up cutting and welding operations are also described.

  1. Improving fatigue performance of rail thermite welds

    Directory of Open Access Journals (Sweden)

    Winiar L.

    2010-06-01

    Full Text Available Rail transport development offers economic and ecological interests. Nevertheless, it requires heavy investments in rolling material and infrastructure. To be competitive, this transportation means must rely on safe and reliable infrastructure, which requires optimization of all implemented techniques and structure. Rail thermite (or aluminothermic welding is widely used within the railway industry for in-track welding during re-rail and defect replacement. The process provides numerous advantages against other welding technology commonly used. Obviously, future demands on train traffic are heavier axle loads, higher train speeds and increased traffic density. Thus, a new enhanced weld should be developed to prevent accidents due to fracture of welds and to lower maintenance costs. In order to improve such assembly process, a detailed metallurgical study coupled to a thermomechanical modelling of the phenomena involved in the thermite welding process is carried out. Obtained data enables us to develop a new improved thermite weld (type A. This joint is made by modifying the routinely specified procedure (type B used in a railway rail by a standard gap alumino-thermic weld. Joints of type A and B are tested and compared. Based on experimental temperature measurements, a finite element analysis is used to calculate the thermal residual stresses induced. In the vicinity of the weld, the residual stress patterns depend on the thermal conditions during welding as it also shown by litterature [1, 2]. In parallel, X-Ray diffraction has been used to map the residual stress field that is generated in welded rail of types A and B. Their effect on fatigue crack growth in rail welds is studied. An experimental study based on fatigue tests of rails welded by conventional and improved processes adjudicates on the new advances and results will be shown.

  2. Improving fatigue performance of rail thermite welds

    Science.gov (United States)

    Jezzini-Aouad, M.; Flahaut, P.; Hariri, S.; Winiar, L.

    2010-06-01

    Rail transport development offers economic and ecological interests. Nevertheless, it requires heavy investments in rolling material and infrastructure. To be competitive, this transportation means must rely on safe and reliable infrastructure, which requires optimization of all implemented techniques and structure. Rail thermite (or aluminothermic) welding is widely used within the railway industry for in-track welding during re-rail and defect replacement. The process provides numerous advantages against other welding technology commonly used. Obviously, future demands on train traffic are heavier axle loads, higher train speeds and increased traffic density. Thus, a new enhanced weld should be developed to prevent accidents due to fracture of welds and to lower maintenance costs. In order to improve such assembly process, a detailed metallurgical study coupled to a thermomechanical modelling of the phenomena involved in the thermite welding process is carried out. Obtained data enables us to develop a new improved thermite weld (type A). This joint is made by modifying the routinely specified procedure (type B) used in a railway rail by a standard gap alumino-thermic weld. Joints of type A and B are tested and compared. Based on experimental temperature measurements, a finite element analysis is used to calculate the thermal residual stresses induced. In the vicinity of the weld, the residual stress patterns depend on the thermal conditions during welding as it also shown by litterature [1, 2]. In parallel, X-Ray diffraction has been used to map the residual stress field that is generated in welded rail of types A and B. Their effect on fatigue crack growth in rail welds is studied. An experimental study based on fatigue tests of rails welded by conventional and improved processes adjudicates on the new advances and results will be shown.

  3. Finite element modelling and updating of friction stir welding (FSW joint for vibration analysis

    Directory of Open Access Journals (Sweden)

    Zahari Siti Norazila

    2017-01-01

    Full Text Available Friction stir welding of aluminium alloys widely used in automotive and aerospace application due to its advanced and lightweight properties. The behaviour of FSW joints plays a significant role in the dynamic characteristic of the structure due to its complexities and uncertainties therefore the representation of an accurate finite element model of these joints become a research issue. In this paper, various finite elements (FE modelling technique for prediction of dynamic properties of sheet metal jointed by friction stir welding will be presented. Firstly, nine set of flat plate with different series of aluminium alloy; AA7075 and AA6061 joined by FSW are used. Nine set of specimen was fabricated using various types of welding parameters. In order to find the most optimum set of FSW plate, the finite element model using equivalence technique was developed and the model validated using experimental modal analysis (EMA on nine set of specimen and finite element analysis (FEA. Three types of modelling were engaged in this study; rigid body element Type 2 (RBE2, bar element (CBAR and spot weld element connector (CWELD. CBAR element was chosen to represent weld model for FSW joints due to its accurate prediction of mode shapes and contains an updating parameter for weld modelling compare to other weld modelling. Model updating was performed to improve correlation between EMA and FEA and before proceeds to updating, sensitivity analysis was done to select the most sensitive updating parameter. After perform model updating, total error of the natural frequencies for CBAR model is improved significantly. Therefore, CBAR element was selected as the most reliable element in FE to represent FSW weld joint.

  4. Electron beam welding and laser welding of FRAGEMA fuel assembly components

    International Nuclear Information System (INIS)

    Couturier, J.M.; Etellin, B.; Duthoo, B.; Wache, C.; Taillandier, T.

    1988-01-01

    Neutron balance and activity of the primary coolant circuit are improved in PWR if inconel 718 is replaced by a zirconium alloy for fuel element grids. This paper examines laser welding and EB welding of these zirconium alloy grids [fr

  5. Interpolation Algorithm and Mathematical Model in Automated Welding of Saddle-Shaped Weld

    Directory of Open Access Journals (Sweden)

    Lianghao Xue

    2018-01-01

    Full Text Available This paper presents welding torch pose model and interpolation algorithm of trajectory control of saddle-shaped weld formed by intersection of two pipes; the working principle, interpolation algorithm, welding experiment, and simulation result of the automatic welding system of the saddle-shaped weld are described. A variable angle interpolation method is used to control the trajectory and pose of the welding torch, which guarantees the constant linear terminal velocity. The mathematical model of the trajectory and pose of welding torch are established. Simulation and experiment have been carried out to verify the effectiveness of the proposed algorithm and mathematical model. The results demonstrate that the interpolation algorithm is well within the interpolation requirements of the saddle-shaped weld and ideal feed rate stability.

  6. The impact of welding wire on the mechanical properties of welded joints

    Directory of Open Access Journals (Sweden)

    Magdalena Mazur

    2014-06-01

    Full Text Available This paper presents results of the mechanical properties of Hardox 450 steel welded joints. These welded joints were made in accordance with welding procedure specifications (WPS, which was prepared and  applied in the Wielton company. Fillers were provided by welding wires with two different diameters. The welding wire was G4Sil with diameter of 1.0 mm and 1.2 mm. The aim of this study was to examine whether the thickness of the welding wire has a direct effect on the properties of welded joints. Test specimens were made in similar parameters of the welding process. Then they were subjected to macroscopic research, tensile strength, impact strength and hardness

  7. Optimization of resistance spot welding parameters for microalloyed steel sheets

    Science.gov (United States)

    Viňáš, Ján; Kaščák, Ľuboš; Greš, Miroslav

    2016-11-01

    The paper presents the results of resistance spot welding of hot-dip galvanized microalloyed steel sheets used in car body production. The spot welds were made with various welding currents and welding time values, but with a constant pressing force of welding electrodes. The welding current and welding time are the dominant characteristics in spot welding that affect the quality of spot welds, as well as their dimensions and load-bearing capacity. The load-bearing capacity of welded joints was evaluated by tensile test according to STN 05 1122 standard and dimensions and inner defects were evaluated by metallographic analysis by light optical microscope. Thewelding parameters of investigated microalloyed steel sheets were optimized for resistance spot welding on the pneumatic welding machine BPK 20.

  8. New Welding Consumables and Practice for Highly Portable Field Repair

    National Research Council Canada - National Science Library

    Olson, D

    2001-01-01

    .... Exothermally assisted arc welding was successfully accomplished with both SMA and self-shielded FCA welding consumables on steels and the optimum range of exothermic additions and welding parameters...

  9. Standard practice for ultrasonic testing of the Weld Zone of welded pipe and tubing

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This practice describes general ultrasonic testing procedures for the detection of discontinuities in the weld and adjacent heat affected zones of welded pipe and tubing by scanning with relative motion between the search unit and pipe or tube. When contact or unfocused immersion search units are employed, this practice is intended for tubular products having specified outside diameters ≥2 in. (≥50 mm) and specified wall thicknesses of 1/8to 11/16 in. (3 to 27 mm). When properly focused immersion search units are employed, this practice may also be applied to material of smaller diameter and thinner wall. Note 1—When contact or unfocused immersion search units are used, precautions should be exercised when examining pipes or tubes near the lower specified limits. Certain combinations of search unit size, frequency, thin–wall thicknesses, and small diameters could cause generation of unwanted sound waves that may produce erroneous examination results. 1.2 All surfaces of material to be examined in ...

  10. Friction stir welding of 6061 aluminium alloy

    International Nuclear Information System (INIS)

    Abdel Rahman, M.A.M.S.

    2009-01-01

    6061 AA (Al-Mg-Si alloy) has gathered wide acceptance in the fabrication of light weight structures requiring a high strength-to-weight ratio and good corrosion resistance such as marine frames, pipelines, storage tanks, and aircraft components [1]. It is also used for the manufacturing of fuel elements in the nuclear research reactors. Compared to many of the fusion welding processes that are routinely used for joining structural alloys, friction stir welding (FSW) is a solid state joining process in which the material that is being welded is not melted and recast [2]. The welding parameters such as tool rotational speed, welding traverse speed, and tool profile play a major role in deciding the weld quality. Several FSW tools (differ from each other in pin angle, shoulder diameter, and shoulder concavity) have been used to fabricate a number of joints in order to obtain a tool with which a sound weld can be produced. It was found that the FSW tool with tapered cone pin, concave shoulder, and shoulder diameter equal to four times the welded plate thickness is suitable to produce a sound weld. The effect of the traverse speed on the global and local tensile properties of friction stir welded joints has been investigated in the 6061-T6 AA. The global tensile properties of the FSW joints were improved with increasing the traverse speed at constant rotation rate. It is found that the global tensile strength of the FSW joint is limited by the local tensile strength of the nearest region to the weld center at which the cross section is composed mainly of the HAZ. The effect of the initial butt surface on the formation of the zigzag line on the tensile properties of the welds was examined by using three types of welding samples differ in the preparation of the initial butt surface. The first type of samples welded without removing the oxide layer from the initial butt surface (uncleaned butt surfaces joint). In the second type of samples the oxide layer was removed from

  11. TIG welding phenomenon and properties of welds in welding atmospheres with various oxygen and nitrogen partial pressures. Pt. 2. Study on welding of zirconium alloy tubing. 5

    International Nuclear Information System (INIS)

    Komuro, Kojiro; Mishima, Teruaki; Kurosawa, Satoshi; Tsuboi, Hajime

    1994-01-01

    The purpose of this study is to investigate the influence of extremely low levels of oxygen and nitrogen partial pressure, P O2 and P N2 in pressurized 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 P O2 and P N2 in total pressure (P T ) of 0.32 MPa (optionally 0.55 MPa), 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 observable at welding in ≤12.9 Pa of P O2 and 15.6-67.2 Pa of P O2+N2 (P O2 /P N2 =1/4), a tendency of arc voltage drop with increase of P N2 is observed at welding in 13.1-53.0 Pa of P N2 (P O2 =0.3 Pa). The surface of weld metal and heat affected zone (HAZ) in the atmosphere of 0.3 Pa of P O2 and 1.3 Pa of P N2 remains bright. The surface discoloration is observable slightly on weld metal and HAZ in the atmosphere of 3.4 Pa of P O2 , and with increase of P O2 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 P N2 ≤ 53.0 Pa with 0.3 Pa of P O2 . The nitrogen content [N] in the weld metal increases linearly with increase of √P N2 , 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 outer part of weld metal increases linearly with increase of √P O2 and shows same relations as [N] although the values of [O] in the weld metals fluctuate more than [N]. The increasing rates of [N] and [O] in the weld metal under P T =0.32 MPa are lower than that of [N] and [O] in the weld metal under P T =0.10 MPa which is reported in Report 3. (author)

  12. Repair welding of cast iron coated electrodes

    Science.gov (United States)

    Żuk, M.; Górka, J.; Dojka, R.; Czupryński, A.

    2017-08-01

    Welding cast iron is a complex production procedure. Repair welding was used to repair damaged or poorly made castings. This is due to a tendency to cracking of the material during welding as well as after it. Welding cast iron can be carried out on hot or on cold. Hot welding requires high heat material and the use of welding material in the form of cast iron. In the case of cold welding, it is possible to use different materials. Mostly used filler metals are nickel and copper based. The work shows the course of research concerning repairmen of ductile iron with arc welding method. For the reparation process four types of ESAB company coated electrodes dedicated for cast iron were used with diameter 3.2 and 4 mm: ES 18-8-6B (4mm), EB 150 (4mm), OK NiCl, EŻM. In the cast iron examined during the testing grooves were made using plasma methods, in order to simulate the removed casting flaws. Then the welding process with coated electrodes was executed. The process utilized low welding current row of 100A, so there would only be a small amount of heat delivered to the heat affected zone (HAZ). Short stitches were made, after welding it was hammered, in order to remove stresses. After the repair welding the part of studies commenced which purpose was finding surface defects using visual testing (VT) and penetration testing (PT). In the second part, a series of macro and microscopic studies were executed witch the purpose of disclosuring the structure. Then the hardness tests for welds cross sections were performed. An important aspect of welding cast iron is the colour of the padding weld after welding, more precisely the difference between the base material and padding weld, the use of different materials extra gives the extra ability to select the best variant. The research of four types of coated electrode was executed, based on the demands the best option in terms of aesthetic, strength and hardness.

  13. Friction Stir Welding of Tapered Thickness Welds Using an Adjustable Pin Tool

    Science.gov (United States)

    Adams, Glynn; Venable, Richard; Lawless, Kirby

    2003-01-01

    Friction stir welding (FSW) can be used for joining weld lands that vary in thickness along the length of the weld. An adjustable pin tool mechanism can be used to accomplish this in a single-pass, full-penetration weld by providing for precise changes in the pin length relative to the shoulder face during the weld process. The difficulty with this approach is in accurately adjusting the pin length to provide a consistent penetration ligament throughout the weld. The weld technique, control system, and instrumentation must account for mechanical and thermal compliances of the tooling system to conduct tapered welds successfully. In this study, a combination of static and in-situ measurements, as well as active control, is used to locate the pin accurately and maintain the desired penetration ligament. Frictional forces at the pin/shoulder interface were a source of error that affected accurate pin position. A traditional FSW pin tool design that requires a lead angle was used to join butt weld configurations that included both constant thickness and tapered sections. The pitch axis of the tooling was fixed throughout the weld; therefore, the effective lead angle in the tapered sections was restricted to within the tolerances allowed by the pin tool design. The sensitivity of the FSW process to factors such as thickness offset, joint gap, centerline offset, and taper transition offset were also studied. The joint gap and the thickness offset demonstrated the most adverse affects on the weld quality. Two separate tooling configurations were used to conduct tapered thickness welds successfully. The weld configurations included sections in which the thickness decreased along the weld, as well as sections in which the thickness increased along the weld. The data presented here include weld metallography, strength data, and process load data.

  14. Analysis of factors affecting fractures of rails welded by alumino-thermic welding

    Directory of Open Access Journals (Sweden)

    Sergejs MIKHAYLOVS

    2008-01-01

    Full Text Available On Latvian Railway the use of the alumino-thermic welding is widespread using the Elektro-Thermit Company technology. Today it is a basic method for rail joints on railway switches. The analysis of the metal structure in the thermic welding and in the thermic welded zone of rails showed that the weld metal had inclusions small pores and nonmetallics. Pores and nonmetallics are not reduce hardness but it is concentrators of stresses and sources of cracks development.

  15. Risk Communication Concerning Welding Fumes for the Primary Preventive Care of Welding Apprentices in Southern Brazil

    OpenAIRE

    Cezar-Vaz, Marta Regina; Bonow, Clarice Alves; Cezar Vaz, Joana

    2015-01-01

    This study’s aim was to assess the perceptions of welding apprentices concerning welding fumes being associated with respiratory and cardiovascular disorders and assess the implementation of risk communication as a primary prevention tool in the welding training process. This quasi-experimental, non-randomized study with before-and-after design was conducted with 84 welding apprentices in Southern Brazil. Poisson Regression analysis was used. Relative Risk was the measure used with a 95% co...

  16. Pearson's Functions to Describe FSW Weld Geometry

    International Nuclear Information System (INIS)

    Lacombe, D.; Coupard, D.; Tcherniaeff, S.; Girot, F.; Gutierrez-Orrantia, M. E.

    2011-01-01

    Friction stir welding (FSW) is a relatively new joining technique particularly for aluminium alloys that are difficult to fusion weld. In this study, the geometry of the weld has been investigated and modelled using Pearson's functions. It has been demonstrated that the Pearson's parameters (mean, standard deviation, skewness, kurtosis and geometric constant) can be used to characterize the weld geometry and the tensile strength of the weld assembly. Pearson's parameters and process parameters are strongly correlated allowing to define a control process procedure for FSW assemblies which make radiographic or ultrasonic controls unnecessary. Finally, an optimisation using a Generalized Gradient Method allows to determine the geometry of the weld which maximises the assembly tensile strength.

  17. Welding and Joining of Titanium Aluminides

    Science.gov (United States)

    Cao, Jian; Qi, Junlei; Song, Xiaoguo; Feng, Jicai

    2014-01-01

    Welding and joining of titanium aluminides is the key to making them more attractive in industrial fields. The purpose of this review is to provide a comprehensive overview of recent progress in welding and joining of titanium aluminides, as well as to introduce current research and application. The possible methods available for titanium aluminides involve brazing, diffusion bonding, fusion welding, friction welding and reactive joining. Of the numerous methods, solid-state diffusion bonding and vacuum brazing have been most heavily investigated for producing reliable joints. The current state of understanding and development of every welding and joining method for titanium aluminides is addressed respectively. The focus is on the fundamental understanding of microstructure characteristics and processing–microstructure–property relationships in the welding and joining of titanium aluminides to themselves and to other materials. PMID:28788113

  18. Femtosecond fiber laser welding of dissimilar metals.

    Science.gov (United States)

    Huang, Huan; Yang, Lih-Mei; Bai, Shuang; Liu, Jian

    2014-10-01

    In this paper, welding of dissimilar metals was demonstrated for the first time, to the best of our knowledge, by using a high-energy high-repetition-rate femtosecond fiber laser. Metallurgical and mechanical properties were investigated and analyzed under various processing parameters (pulse energy, repetition rate, and welding speed). Results showed that the formation of intermetallic brittle phases and welding defects could be effectively reduced. Strong welding quality with more than 210 MPa tensile strength for stainless steel-aluminum and 175 MPa tensile strength for stainless steel-magnesium has been demonstrated. A minimal heat affected zone and uniform and homogenous phase transformation in the welding region have been demonstrated. This laser-welding technique can be extended for various applications in semiconductor, automobile, aerospace, and biomedical industries.

  19. Orbital friction stir welding of aluminium pipes

    International Nuclear Information System (INIS)

    Engelhard, G.; Hillers, T.

    2002-01-01

    Friction stir welding (FSW) was originally developed for flat plates. This contribution shows how it can be applied to the welding of aluminium pipes. Pipes made of AlMG 3 (EN5754), AlMg 4.5Mn (EN5083) and AlMgSi 0.5 (EN6106) with dimensions of Da 600 and 520 x 10-8 mm were welded. The FSW orbital system comprises an annular cage with integrated FSW head, a hydraulic system, and a control unit. The welds were tested successfully according to EN 288. The mechanical and technical properties of the welds were somewhat better than with the TIG orbital process, and welding times were about 40 percent shorter [de

  20. Underwater laser beam welding of Alloy 690

    International Nuclear Information System (INIS)

    Hino, Takehisa; Tamura, Masataka; Kono, Wataru; Kawano, Shohei; Yoda, Masaki

    2009-01-01

    Stress Corrosion Clacking (SCC) has been reported at Alloy 600 welds between nozzles and safe-end in Pressurized Water Reactor (PWR) plant. Alloy 690, which has higher chromium content than Alloy 600, has been applied for cladding on Alloy 600 welds for repairing damaged SCC area. Toshiba has developed Underwater Laser Beam Welding technique. This method can be conducted without draining, so that the repairing period and the radiation exposure during the repair can be dramatically decreased. In some old PWRs, high-sulfur stainless steel is used as the materials for this section. It has a high susceptibility of weld cracks. Therefore, the optimum welding condition of Alloy 690 on the high-sulfur stainless steel was investigated with our Underwater Laser Beam Welding unit. Good cladding layer, without any crack, porosity or lack of fusion, could be obtained. (author)