Sample records for submerged-arc welds hssi

  1. Irradiation effects on fracture toughness of two high-copper submerged-arc welds, HSSI Series 5. Volume 1, Main report and Appendices A, B, C, and D

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    Nanstad, R.K.; Haggag, F.M.; McCabe, D.E.; Iskander, S.K.; Bowman, K.O. [Oak Ridge National Lab., TN (United States); Menke, B.H. [Materials Engineering Associates, Inc., Lanham, MD (United States)


    The Fifth Irradiation Series in the Heavy-Section Steel Irradiation Program obtained a statistically significant fracture toughness data base on two high-copper (0.23 and 0.31 wt %) submerged-arc welds to determine the shift and shape of the K{sub Ic} curve as a consequence of irradiation. Compact specimens with thicknesses to 101.6 mm (4 in) in the irradiated condition and 203.2 mm (8 in) in the unirradiated condition were tested, in addition to Charpy impact, tensile, and drop-weight specimens. Irradiations were conducted at a nominal temperature of 288{degree}C and an average fluence of 1.5 {times} 10{sup 19} neutrons/cm{sup 2} (>l MeV). The Charpy 41-J temperature shifts are about the same as the corresponding drop-weight NDT temperature shifts. The irradiated welds exhibited substantial numbers of cleavage pop-ins. Mean curve fits using two-parameter (with fixed intercept) nonlinear and linearized exponential regression analysis revealed that the fracture toughness 100 MPa{lg_bullet}{radical}m shifts exceeded the Charpy 41-J shifts for both welds. Analyses of curve shape changes indicated decreases in the slopes of the fracture toughness curves, especially for the higher copper weld. Weibull analyses were performed to investigate development of lower bound curves to the data, including the use of a variable K{sub min} parameter which affects the curve shape.

  2. Laser Beam Submerged Arc Hybrid Welding (United States)

    Reisgen, Uwe; Olschok, Simon; Jakobs, Stefan; Schleser, Markus; Mokrov, Oleg; Rossiter, Eduardo

    The laser beam-submerged arc hybrid welding method originates from the knowledge that, with increasing penetration depth, the laser beam process has a tendency to pore formation in the lower weld regions. The coupling with the energy-efficient submerged-arc process improves degassing and reduces the tendency to pore formation. The high deposition rate of the SA process in combination with the laser beam process offers, providing the appropriate choice of weld preparation, the possibility of welding plates with a thickness larger than 20° mm in a single pass, and also of welding thicker plates with the double-sided single pass technique.

  3. Submerged arc welding of heavy plate (United States)

    Wilson, R. A.


    The submerged arc process is particularly suitable for heavy plate welding because of its ability to combine very high deposit rates along with excellent quality. It does these things without the smoke and spatter often accompanying other processes. It is available today in several forms that are pointed to the fabricators of heavy sections with long, short or round about welds. Tandem arc full automatic equipment is particularly suitable for those long heavy welds where speed and deposit rate are of the first order. An attachment called long stick-out which makes use of the IR drop on long electrode extensions can be included on this equipment to increase deposition rates 50% or more.

  4. Hydrogen mitigation in submerged arc welding (United States)

    Klimowicz, Steven

    With the role of hydrogen in weld metal well understood in its relation to cold cracking, there has been a push to produce welds with lower and lower diffusible hydrogen contents. The push for lower diffusible hydrogen contents has placed pressure on consumables manufactures to create consumables that can achieve the requirements for lower diffusible hydrogen content. Currently EM12K flux is produced so that it can achieve below 4 ml of diffusible hydrogen for every 100g of weld metal deposited (ml/100g) for submerged arc welding (SAW). The recent trend for industry is to preferentially achieve diffusible hydrogen contents below 3 ml/100g. Making it necessary to find a way to modify the flux to achieve a lower diffusible hydrogen content for the welds it produces. To achieve this goal a two phase plan was developed. The first phase was to characterize the entire welding system for hydrogen. Since the goal of the project is hydrogen mitigation, any amount of hydrogen that could be reduced is helpful and therefore must first be discovered. Sources of hydrogen may be found by analyzing the welding wire and base metal, as well as breaking the flux down into its components and production steps. The wire was analyzed for total hydrogen content as was the base metal. The flux and its components were analyzed using differential thermal analysis-simultaneous thermal analysis (DTA-STA) and later vacuum degassing for moisture content. The analysis of the wire showed that the copper coating on the wire was the largest contributor of hydrogen. There was lubricant present on the wire surface as well, but it did not contribute as much as the copper coating. It was found that a simple low temperature baking of the wire was enough to remove the lubricant and coating moisture. The base metal was found to have a similar total hydrogen content to that of the wire. The breakdown of the flux and production process for moisture content analysis revealed that the production process

  5. Peculiarities of thermal dissociation of oxides during submerged arc welding

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    Leonid Zhdanov


    Full Text Available A method of settlement of the process of thermal dissociation of oxides in reaction zone during the submerged arc welding and welding deposition is presented. Combined non-linear equations for definition of gas-vapour mixture composition were developed. They describe the dissociation of MeO, MeO2 and Me2O3 types of oxides. Calculations of the processes of oxide dissociation were performed for the oxides that are commonly included into welding fluxes. Their results and analysis are presented. The method proposed appeared to be adequate and applicable for analysis of processes during submerged arc operation that run in the gas phase.

  6. Implementation of Submerged Arc Welding Training. Final Report. (United States)

    Bowick, Earl; Todd, John

    A unit on submerged arc welding (SAW) was developed and integrated into the welding program at Seattle Central Community College (Washington) during the period December 1983 through May 1984. During this time, 10 major users of SAW in the area were contacted and mailed questionnaires. Follow up consisted of telephone calls and personal contact as…

  7. Critical Assessment of Temperature Distribution in Submerged Arc Welding Process

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    Vineet Negi


    Full Text Available Temperature distribution during any welding process holds the key for understanding and predicting several important welding attributes like heat affected zone, microstructure of the weld, residual stress, and distortion during welding. The accuracy of the analytical approaches for modeling temperature distribution during welding has been constrained by oversimplified assumptions regarding boundary conditions and material properties. In this paper, an attempt has been made to model the temperature distribution during submerged arc welding process using finite element modeling technique implemented in ANSYS v12. In the present analysis, heat source is assumed to be double-ellipsoidal with Gaussian volumetric heat generation. Furthermore, variation of material properties with temperature and both convective and radiant heat loss boundary condition have been considered. The predicted temperature distribution is then validated against the experimental results obtained by thermal imaging of the welded plate, and they are found to be in a good agreement.

  8. Slag Metal Reactions during Submerged Arc Welding of Alloy Steels (United States)

    Mitra, U.; Eagar, T. W.


    The transfer of Cr, Si, Mn, P, S, C, Ni, and Mo between the slag and the weld pool has been studied for submerged arc welds made with calcium silicate and manganese silicate fluxes. The results show a strong interaction between Cr and Si transfer but no interaction with Mn. The manganese silicate flux produces lower residual sulfur while the calcium silicate fluxes are more effective for removal of phosphorus. The effective oxygen reaction temperature lies between 1700 and 2000 °C for all elements studied. Evidence of Cr and Mn loss by metal vaporization is also presented.

  9. Arc characteristics of submerged arc welding with stainless steel wire (United States)

    Li, Ke; Wu, Zhi-sheng; Liu, Cui-rong; Chen, Feng-hua


    The arc characteristics of submerged arc welding (SAW) with stainless steel wire were studied by using Analysator Hannover (AH). The tests were carried out under the same preset arc voltage combined with different welding currents. By comparing the probability density distribution (PDD) curves of arc voltage and welding current, the changes were analyzed, the metal transfer mode in SAW was deduced, and the characteristics of a stable arc were summarized. The analysis results show that, with an increase of welding parameters, the short-circuiting peak in the PDD curves of arc voltage decreases gradually until it disappears, and the dominant metal transfer mode changes from flux-wall guided transfer to projected transfer and then to streaming transfer. Moreover, when the PDD curves of arc voltage are both unimodal and generally symmetrical, the greater the peak probability and the smaller the peak span, the more stable the arc becomes.

  10. Slag-metal equilibrium during submerged arc welding (United States)

    Chai, C. S.; Eagar, T. W.


    A thermodynamic model of the equilibria existing between the slag and the weld metal during submerged arc welding is presented. As formulated, the model applies only to fused neutral fluxes containing less than 20 pct CaF2, however some results indicate that the model may be useful in more general cases as well. The model is shown to be capable of predicting the gain or loss of both Mn and Si over a wide range of baseplate, electrode and flux compositions. At large deviations from the predicted equilibrium, the experimental results indicate considerable variability in the amount of Mn or Si transferred between the slag and metal phases, while closer to the calculated equilibrium, the extent of metal transfer becomes more predictable. The variability in metal transfer rate at large deviations from equilibrium may be explained by variations between the bulk and the surface concentrations of Mn and Si in both metal and slag phases.

  11. The Development of a Composite Consumable Insert for Submerged ARC Welding

    National Research Council Canada - National Science Library


    .... When the submerged arc process was utilized to weld the butt joint in large flat plate structures, the repositioning of the plate for welding of the reverse side was a costly time consuming procedure...

  12. Meta Modelling of Submerged-Arc Welding Design based on Fuzzy Algorithm (United States)

    Song, Chang-Yong; Park, Jonghwan; Goh, Dugab; Park, Woo-Chang; Lee, Chang-Ha; Kim, Mun Yong; Kang, Jinseo


    Fuzzy algorithm based meta-model is proposed for approximating submerged-arc weld design factors such as weld speed and weld output. Orthogonal array design based on the submerged-arc weld numerical analysis is applied to the proposed approach. The nonlinear finite element analysis is carried out to simulate the submerged-arc weld numerical analysis using thermo-mechanical and temperature-dependent material properties for general mild steel. The proposed meta-model based on fuzzy algorithm design is generated with triangle membership functions and fuzzy if-then rules using training data obtained from the Taguchi orthogonal array design data. The aim of proposed approach is to develop a fuzzy meta-model to effectively approximate the optimized submerged-arc weld factors. To validate the meta-model, the results obtained from the fuzzy meta-model are compared to the best cases from the Taguchi orthogonal array.

  13. Stainless steel submerged arc weld fusion line toughness

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    Rosenfield, A.R.; Held, P.R.; Wilkowski, G.M. [Battelle, Columbus, OH (United States)


    This effort evaluated the fracture toughness of austenitic steel submerged-arc weld (SAW) fusion lines. The incentive was to explain why cracks grow into the fusion line in many pipe tests conducted with cracks initially centered in SAWS. The concern was that the fusion line may have a lower toughness than the SAW. It was found that the fusion line, Ji. was greater than the SAW toughness but much less than the base metal. Of greater importance may be that the crack growth resistance (JD-R) of the fusion line appeared to reach a steady-state value, while the SAW had a continually increasing JD-R curve. This explains why the cracks eventually turn to the fusion line in the pipe experiments. A method of incorporating these results would be to use the weld metal J-R curve up to the fusion-line steady-state J value. These results may be more important to LBB analyses than the ASME flaw evaluation procedures, since there is more crack growth with through-wall cracks in LBB analyses than for surface cracks in pipe flaw evaluations.

  14. Multi-Objective Optimization of Submerged Arc Welding Process

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    Saurav Datta


    Full Text Available Submerged arc welding (SAW is an important metal fabrication technology specially applied to join metals of large thickness in a single pass. In order to obtain an efficient joint, several process parameters of SAW need to be studied and precisely selected to improve weld quality. Many methodologies were proposed in the past research to address this issue. However, a good number of past work seeks to optimize SAWprocess parameters with a single response only. In practical situations, not only is the influence of process parameters and their interactive effects on output responses are to be critically examined but also an attempt is to be made to optimize more than one response, simultaneously. To this end, the present study considers four process control parameters viz. voltage (OCV, wire feed rate, traverse speed and electrode stick-out. The selected weld quality characteristics related to features of bead geometry are depth of penetration, reinforcement and bead width. In the present reporting, an integrated approach capable of solving the simultaneous optimization of multi-quality responses in SAW was suggested. In the proposed approach, the responses were transformed into their individual desirability values by selecting appropriate desirability function. Assuming equal importance for all responses, these individual desirability values were aggregated to calculate the overall desirability values. Quadratic Response Surface Methodology (RSM was applied to establish a mathematical model representing overall desirability as a function involving linear, quadratic and interaction effect of process control parameters. This model was optimized finally within the experimental domain using PSO (Particle Swarm Optimization algorithm. A confirmatory test showed a satisfactory result. A detailed methodology of RSM, desirability function (DF and a PSO-based optimization approach was illustrated in the paper.

  15. Possibilities of Application of Carbon-Fluorine Containing Additions in Submerged-Arc Welding (United States)

    Kozyrev, N. A.; Kryukov, N. E.; Kryukov, R. E.; Igushev, V. F.; Kovalskii, I. I.


    The paper provides results of comparative analysis of the effect of carbonaceous components introduced into welding fluxes on molten metal - slag interaction. A positive influence of carbonaceous additives on gas content and mechanical properties of welds is demonstrated. Carbon and fluorine containing additives are emphasized to be promising for automatic submerged arc welding.

  16. Parameter optimization of flux-aided backing-submerged arc welding by using Taguchi method (United States)

    Pu, Juan; Yu, Shengfu; Li, Yuanyuan


    Flux-aided backing-submerged arc welding has been conducted on D36 steel with thickness of 20 mm. The effects of processing parameters such as welding current, voltage, welding speed and groove angle on welding quality were investigated by Taguchi method. The optimal welding parameters were predicted and the individual importance of each parameter on welding quality was evaluated by examining the signal-to-noise ratio and analysis of variance (ANOVA) results. The importance order of the welding parameters for the welding quality of weld bead was: welding current > welding speed > groove angle > welding voltage. The welding quality of weld bead increased gradually with increasing welding current and welding speed and decreasing groove angle. The optimum values of the welding current, welding speed, groove angle and welding voltage were found to be 1050 A, 27 cm/min, 40∘ and 34 V, respectively.

  17. Effect of Post-Welding Heat Treatment on Mechanical Properties of Joints of Steel P92 Formed by Submerged Arc Welding (United States)

    Mohyla, P.; Foldynová, K.


    Results of mechanical tests and metallographic studies of welded joints of steel P92 obtained by submerged arc welding are presented. The effect of the post-welding heat treatment on the mechanical properties of the welds is described.

  18. XRD and DTA Analysis of Developed Agglomerated Fluxes for Submerged Arc Welding

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    Ajay Kumar


    Full Text Available A unique study of structural and chemical analysis of crystalline phases in developed agglomerated fluxes was carried out. Thirty-two fluxes were developed by using a mixture of oxides, halides, carbonates, silicates, and ferroalloys for submerged arc welding. The present paper focuses on only ten (out of thirty-two fluxes which were analyzed by X-ray diffraction (XRD to know the different types of oxides formed and changed in oxidation number of metallic centers after sintering process at around 850∘C. To know the effect of temperature over phase transformation and melting of different compounds, differential thermal analysis (DTA was carried out from 1000 to 1400∘C. This study aims to know the quantity of ions present (percentage and melting behavior of developed agglomerated fluxes for submerged arc welding process.

  19. Study the Effect of SiO2 Based Flux on Dilution in Submerged Arc Welding (United States)

    kumar, Aditya; Maheshwari, Sachin


    This paper highlights the method for prediction of dilution in submerged arc welding (SAW). The most important factors of weld bead geometry are governed by the weld dilution which controls the chemical and mechanical properties. Submerged arc welding process is used generally due to its very easy control of process variables, good penetration, high weld quality, and smooth finish. Machining parameters, with suitable weld quality can be achieved with the different composition of the flux in the weld. In the present study Si02-Al2O3-CaO flux system was used. In SiO2 based flux NiO, MnO, MgO were mixed in various proportions. The paper investigates the relationship between the process parameters like voltage, % of flux constituents and dilution with the help of Taguchi’s method. The experiments were designed according to Taguchi L9 orthogonal array, while varying the voltage at two different levels in addition to alloying elements. Then the optimal results conditions were verified by confirmatory experiments.

  20. Laser Submerged Arc Welding (LUPuS) with Solid State Lasers (United States)

    Reisgen, Uwe; Olschok, Simon; Jakobs, Stefan

    The laser beam-submerged arc hybrid welding method originates from the knowledge that, with increasing penetration depth, the laser beam process has a tendency to pore formation in the lower weld regions. The coupling with the energy-efficient submerged-arc process improves degassing and reduces the tendency to pore formation. The newly developed hybrid welding process allows the welding of plates with a thickness larger than 20 mm in a single pass and the welding of thicker plates with the double-sided single pass technique. In this special hybrid process, the use of CO2-lasers causes problems when forward sliding flux of slag meets the laser beam path and forms an uncontrollable plasma plume in the beam path. This plasma then shields the work piece from the laser power and thus provokes the collapse of the laser keyhole and leads to process instability. The substitution of the CO2-laser with a modern solid-state laser significantly improves the performance and the stability of the hybrid process. This contribution will demonstrate the latest results and improvements by means of welding results gained with steel plates with a thickness of up to 40mm.

  1. Characterisation of submerged arc welding process using infrared imaging technique

    CSIR Research Space (South Africa)

    Zondi, MC


    Full Text Available Infrared (IR) thermography is a technique used to measure temperature distribution of heat generation in manufacturing processes such as welding. IR thermography is a non-destructive and non-contact method, which makes it favoured for the arc...

  2. Double-Sided Single-Pass Submerged Arc Welding for 2205 Duplex Stainless Steel (United States)

    Luo, Jian; Yuan, Yi; Wang, Xiaoming; Yao, Zongxiang


    The duplex stainless steel (DSS), which combines the characteristics of ferritic steel and austenitic steel, is used widely. The submerged arc welding (SAW) method is usually applied to join thick plates of DSS. However, an effective welding procedure is needed in order to obtain ideal DSS welds with an appropriate proportion of ferrite (δ) and austenite (γ) in the weld zone, particularly in the melted zone and heat-affected zone. This study evaluated the effectiveness of a high efficiency double-sided single-pass (DSSP) SAW joining method for thick DSS plates. The effectiveness of the converse welding procedure, characterizations of weld zone, and mechanical properties of welded joint are analyzed. The results show an increasing appearance and continuous distribution feature of the σ phase in the fusion zone of the leading welded seam. The converse welding procedure promotes the σ phase to precipitate in the fusion zone of leading welded side. The microhardness appears to significantly increase in the center of leading welded side. Ductile fracture mode is observed in the weld zone. A mixture fracture feature appears with a shear lip and tears in the fusion zone near the fusion line. The ductility, plasticity, and microhardness of the joints have a significant relationship with σ phase and heat treatment effect influenced by the converse welding step. An available heat input controlling technology of the DSSP formation method is discussed for SAW of thick DSS plates.

  3. Development of Process Maps in Two-Wire Tandem Submerged Arc Welding Process of HSLA Steel (United States)

    Kiran, D. V.; Alam, S. A.; De, A.


    Appropriate selection of welding conditions to guarantee requisite weld joint mechanical properties is ever difficult because of their complex interactions. An approach is presented here to identify suitable welding conditions in typical two-wire tandem submerged arc welding (SAW-T) that involves many welding variables. First, an objective function is defined, which depicts the squared error between the mechanical properties of weld joint and of base material. A set of artificial neural network (ANN)-based models are developed next to estimate the weld joint properties as function of welding conditions using experimentally measured results. The neural network model-based predictions are used next to create a set of process map contours that depict the minimum achievable values of the objective function and the corresponding welding conditions. In typical SAW-T of HSLA steel, welding speed from 9.0 to 11.5 mm/s, leading wire current from 530 to 580 A, and trailing wire negative current from 680 to 910 A are found to be the most optimal.

  4. The influence of plate thickness on the welding residual stresses from submerged arc welding in offshore steel structures

    DEFF Research Database (Denmark)

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


    to an improved design, which consequently may be included in future norms and standards. Submerged Arc Welding (SAW) was used to make a fully penetrated butt weld in 10 mm and 40 mm thick steel plates with the same welding parameters as used in the production procedures. The base material is thermomechanical hot......Welding-induced residual tensile stresses and distortion have become a major concern in relation to the structural integrity of welded structures within the offshore wind industry. The stresses have a negative impact on the integrity of the welded joint, as they promote distortion, reduce fatigue...... life, and attribute to the corrosion cracking and brittle fracture in the weld components. This study investigates the influence of plate thickness on the welding-induced residual stresses. The residual stresses are investigated through experiments and in accordance with existing production procedures...

  5. Numerical simulation of temperature field in multiple-wire submerged arc welding of X80 pipeline steel (United States)

    Yan, Chunyan; Jiang, Han; Wu, Lichao; Kan, Chenxia; Yu, Wen


    Three dimensional (3D) finite element (FE) simulation was implemented to predict the temperature distribution during multiple-wire submerged arc welding (SAW) throughout the welded joint of X80 pipeline steel. A moving heat source model based on Goldak’s double-ellipsoid heat flux distribution was applied in the simulation to capture the heating effect of the welding arc. Effects of welding speed, wire spacing and leading wire current on temperature distribution were further investigated. The simulation results show that both welding speed and wire spacing have significant effects on welding temperature distribution in X80 pipeline steel welded joint.

  6. Effect of Submerged Arc Welding Parameters on the Microstructure of SA516 and A709 Steel Welds (United States)

    Amanie, James

    The effects of submerged arc welding (SAW) current and speed on the microstructures of SA516 grade 70 and A709 grade 50 steel welds were studied in this research. Steel plates 17 mm-thick were submerged arc welded using different welding currents (from 700 to 850 A) and welding speeds (from 5.3 to 15.3 mm/s). The effect of heat input on the weld metal chemistry, morphologies and chemistry of inclusions and nucleation of acicular ferrite (AF), grain boundary ferrite (GBF) and Widmanstatten ferrite (WF) were evaluated. Optical microscopy (OM), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) microanalysis and transmission electron microscopy (TEM) were used to examine the microstructures of the developed weld joints. PAX-it image analysis software program was utilized for quantitative analysis of the microstructures. The results showed that it is difficult to ascribe changes in the microstructure that occurred in the heat affected zone (HAZ) and the weld metal regions to a single welding process parameter. Inclusion analysis revealed two types of inclusions formed in the weld metals for both steels. They are spherical and faceted inclusions. It was also observed that acicular ferrite nucleated only on the spherical inclusions. EDS analysis showed that the two inclusions have different chemical compositions. The results further showed that the total oxygen content of the weld metals of both steels generally increased with welding current, but decreased with increasing welding speed. The prior austenite grain width decreased with increasing welding speed, but increased with increasing welding current (increased heat input). For both SA516 and A709 steel welds, the proportion of acicular ferrite (AF) in the weld metals increased initially, while those of grain boundary ferrite (GBF) and Widmanstatten ferrite (WF) decreased with increasing welding current when welding current was increased from 700 A to 800 A. With further increase in the

  7. Effect of Different Current Values on Microstructure and Mechanical Properties of Microalloyed Steels Joined by the Submerged Arc Welding Method

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    Hasan Karabulut


    Full Text Available In this study, microalloyed steels were joined by using the submerged arc welding method at different welding currents of 350 A, 400 A and 450 A. The effects of selected welding parameters on the microstructure and mechanical properties of welded materials were investigated. Tensile tests and microhardness measurements were performed. Microstructural changes have been identified in the welding zone. The results showed an increase in hardness and tensile strength depending on the current intensity. The heat affected zone was observed much wider with the increase in welding current.

  8. Optimization of submerged arc welding process parameters using quasi-oppositional based Jaya algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Rao, R. Venkata; Rai, Dhiraj P. [Sardar Vallabhbhai National Institute of Technology, Gujarat (India)


    Submerged arc welding (SAW) is characterized as a multi-input process. Selection of optimum combination of process parameters of SAW process is a vital task in order to achieve high quality of weld and productivity. The objective of this work is to optimize the SAW process parameters using a simple optimization algorithm, which is fast, robust and convenient. Therefore, in this work a very recently proposed optimization algorithm named Jaya algorithm is applied to solve the optimization problems in SAW process. In addition, a modified version of Jaya algorithm with oppositional based learning, named “Quasi-oppositional based Jaya algorithm” (QO-Jaya) is proposed in order to improve the performance of the Jaya algorithm. Three optimization case studies are considered and the results obtained by Jaya algorithm and QO-Jaya algorithm are compared with the results obtained by well-known optimization algorithms such as Genetic algorithm (GA), Particle swarm optimization (PSO), Imperialist competitive algorithm (ICA) and Teaching learning based optimization (TLBO).

  9. Nuclear Technology. Course 28: Welding Inspection. Module 28-3, Tungsten Inert Gas (TIG), Metal Inert Gas (MIG) and Submerged Arc Welding. (United States)

    Espy, John

    This third in a series of ten modules for a course titled Welding Inspection presents the apparatus, process techniques, procedures, applications, associated defects, and inspection for the tungsten inert gas, metal inert gas, and submerged arc welding processes. The module follows a typical format that includes the following sections: (1)…

  10. Effects of flux composition on the element transfer and mechanical properties of weld metal in submerged arc welding (United States)

    Bang, Kook-soo; Park, Chan; Jung, Hong-chul; Lee, Jong-bong


    Submerged arc welding was performed using metal-cored wires and fluxes with different compositions. The effects of wire/flux combination on the chemical composition, tensile strength, and impact toughness of the weld metal were investigated and interpreted in terms of element transfer between the slag and the weld metal, i.e., Δ quantity. Both carbon and manganese show negative Δ quantity in most combinations, indicating the transfer of the elements from the weld metal to the slag during welding. The amount of transfer, however, is different depending on the flux composition. More basic fluxes yield less negative Δ C and Δ Mn through the reduction of oxygen content in the weld metal and presumably higher Mn activity in the slag, respectively. The transfer of silicon, however, is influenced by Al2O3, TiO2 and ZrO2 contents in the flux. Δ Si becomes less negative and reaches a positive value of 0.044 as the oxides contents increase. This is because Al, Ti, and Zr could replace Si in the SiO2 network, leaving more Si free to transfer from the slag to the weld metal. Accordingly, the Pcm index of weld metals calculated from chemical compositions varies from 0.153 to 0.196 depending on the wire/flux combination, and it almost has a linear relationship with the tensile strength of the weld metal.

  11. Effect of Flux Composition on the Percentage Elongation and Tensile Strength of Welds in Submerged Arc Welding

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    Singh Brijpal


    Full Text Available This experimental study reveals the effects of CaF2, FeMn and NiO additions to the base fluxes on tensile strength and percentage elongation of the weld metal. The aim of this study is to develop suitable flux for mild steel for high tensile strength, impact strength and ductility. Bead on plate welds were made using submerged arc welding process. Mathematical model for percentage elongation and UTS of mild steel welds were made. The elements transfer to the welds have been correlated with the above mechanical performance characteristics. The effect of oxygen content on weld elongation and UTS also has been deduced. This study shows that CaF2 and NiO are the significant factors for tensile strength while FeMn is not significant for tensile strength. However, for elongation besides CaF2, the interaction of CaF2 and FeMn was also found significant. The effects of basicity index of the flux and carbon equivalent of the welds on tensile strength and percentage elongation of the welds have also been evaluated.

  12. Submerged-arc welding slags: characterization and leaching strategies for the removal of aluminum and titanium. (United States)

    Annoni, Raquel; Souza, Poliana Santos; Petrániková, Martina; Miskufova, Andrea; Havlík, Tomáš; Mansur, Marcelo Borges


    In the present study, submerged-arc welding slags were characterized by applying a variety of methods, including X-ray fluorescence, X-ray diffraction, particle size, Raman spectroscopy, and scanning electron microscope with energy dispersive X-ray analysis. The content of Al proved to be quite similar within neutral and acid slags (10-14%), while that of Ti proved to be much higher in acid slags (approximately 10%) than in neutral slags (<1%). The presence of spinel structures associated with Al species could also be identified in the analyzed samples. This characterization study was accompanied by leaching tests performed under changing operating conditions in an attempt to evaluate to what extent the Al and Ti bearing components could be removed from the slags. The leaching work involved three distinct strategies: (i) NaOH leaching followed by H(2)SO(4) leaching, (ii) acid leaching (HCl and H(2)SO(4)) using oxidizing/reducing agents, and (iii) slag calcination followed by H(2)SO(4) leaching. In the best result, 80% of Al was extracted in one single leaching stage after calcination of the acid slag with NaCl+C at 900 °C. By contrast, the removal of Ti proved to be unsatisfactory. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Effect of Hot-Bending Process on Microstructure and Mechanical Property of K65 Submerged ARC Welded Pipe (United States)

    Dong, Liming; Zhang, Yu; Pan, Xin; Wang, Yinbai

    Hot-bended pipes are essential parts in the construction of long distance pipeline. They are usually made from longitudinally submerged arc welding (LSAW) pipes subjected to hot bending process including quenching and tempering process, which often deteriorates the impact property of the welded pipe. A hot-bended LSAW pipe with a wall thickness of 30.8 mm was fabricated by double-sided four wires submerged arc welding with solid wire and fused flux. Microstructural and property of both as-weld and as-bended pipe were examined. The pipes in two states show a similar tensile strength of 665-670 MPa, and fail in the heat affected zone during the tensile test. The weld metal of as-welded pipe consists of acicular ferrite and small fraction bainite and M-A constituents, while mixture of polygonal ferrite, degenerate perlite and precipitated carbides of metal elements was found in the weld metal of the as-bended pipe. The hot bending process decreases the fraction of acicular ferrite from 66.4 to 47.5%, and the fraction of high angle grain boundary from 76.8 to 67.1%. Therefore, both the type of microstructure and the fraction of ductile microstructures were the influencing factors of weld metal impact toughness, which lead to a reduction from 162 J to 84 J at -40°C.

  14. Characterization of HAZ of API X70 Microalloyed Steel Welded by Cold-Wire Tandem Submerged Arc Welding (United States)

    Mohammadijoo, Mohsen; Kenny, Stephen; Collins, Laurie; Henein, Hani; Ivey, Douglas G.


    High-strength low-carbon microalloyed steels may be adversely affected by the high-heat input and thermal cycle that they experience during tandem submerged arc welding. The heat-affected zone (HAZ), particularly the coarse-grained heat-affected zone (CGHAZ), i.e., the region adjacent to the fusion line, has been known to show lower fracture toughness compared with the rest of the steel. The deterioration in toughness of the CGHAZ is attributed to the formation of martensite-austenite (M-A) constituents, local brittle zones, and large prior austenite grains (PAG). In the present work, the influence of the addition of a cold wire at various wire feed rates in cold-wire tandem submerged arc welding, a recently developed welding process for pipeline manufacturing, on the microstructure and mechanical properties of the HAZ of a microalloyed steel has been studied. The cold wire moderates the heat input of welding by consuming the heat of the trail electrode. Macrostructural analysis showed a decrease in the CGHAZ size by addition of a cold wire. Microstructural evaluation, using both tint etching optical microscopy and scanning electron microscopy, indicated the formation of finer PAGs and less fraction of M-A constituents with refined morphology within the CGHAZ when the cold wire was fed at 25.4 cm/min. This resulted in an improvement in the HAZ impact fracture toughness. These improvements are attributed to lower actual heat introduced to the weldment and lower peak temperature in the CGHAZ by cold-wire addition. However, a faster feed rate of the cold wire at 76.2 cm/min adversely affected the toughness due to the formation of slender M-A constituents caused by the relatively faster cooling rate in the CGHAZ.

  15. Optimization of Welding Parameters of Submerged Arc Welding Using Analytic Hierarchy Process (AHP) Based on Taguchi Technique (United States)

    Sarkar, A.; Roy, J.; Majumder, A.; Saha, S. C.


    The present paper reports a new procedure using an analytic hierarchy process (AHP) based Taguchi method for the selection of the best welding parameters to fabricate submerged arc welding of plain carbon steel. Selection of best welding parameters is an unstructured decision problem involving process parameters for multiple weldments. In the present investigation, three process parameter variables i.e. wire feed rate (Wf), stick out (So) and traverse speed (Ts) and the three response parameters i.e. penetration, bead width and bead reinforcement have been considered. The objective of the present work is thus to improve the quality of the welded elements by using AHP analysis based Taguchi method. Taguchi L16 orthogonal array is used to perform with less number of experimental runs. Taguchi approach is insufficient to solve a multi response optimization problem. In order to overcome this limitation, a multi criteria decision making method, AHP is applied in the present study. The optimal condition to have a quality weld (i.e. bead geometry) is found at 210 mm/min of wire feed rate, 15 mm of stick out and 0.75 m/min of traverse speed and also observed that the effect of wire feed rate on the overall bead geometry properties is more significant than other welding parameters. Finally, a confirmatory test has been carried out to verify the optimal setting so obtained.

  16. Microstructural changes of a thermally aged stainless steel submerged arc weld overlay cladding of nuclear reactor pressure vessels (United States)

    Takeuchi, T.; Kameda, J.; Nagai, Y.; Toyama, T.; Matsukawa, Y.; Nishiyama, Y.; Onizawa, K.


    The effect of thermal aging on microstructural changes in stainless steel submerged arc weld-overlay cladding of reactor pressure vessels was investigated using atom probe tomography (APT). In as-received materials subjected to post-welding heat treatments (PWHTs), with a subsequent furnace cooling, a slight fluctuation of the Cr concentration was observed due to spinodal decomposition in the δ-ferrite phase but not in the austenitic phase. Thermal aging at 400 °C for 10,000 h caused not only an increase in the amplitude of spinodal decomposition but also the precipitation of G phases with composition ratios of Ni:Si:Mn = 16:7:6 in the δ-ferrite phase. The degree of the spinodal decomposition in the submerged arc weld sample was similar to that in the electroslag weld one reported previously. We also observed a carbide on the γ-austenite and δ-ferrite interface. There were no Cr depleted zones around the carbide.

  17. Experimental Investigation for Multi-Response Optimization of Bead Geometry in Submerged Arc Welding using Grey Analysis (United States)

    Bhattacharya, A.; Batish, A.; Kumar, P.


    The present study was aimed at studying the effect of type and composition of flux, welding current, arc voltage, and travel speed on depth of penetration, bead height and bead width (bead geometry responses) and to optimize the process considering multi-response criteria in a submerged arc welding process. Using the grey relational analysis technique three responses were combined into a single grey relational grade and was analyzed using Analysis of Variance. Since the three responses had conflicting requirements, optimization of the complicated multiple performance characteristics was greatly simplified through this approach. The emperical relationship between the multi-response grey relational grade and the input parameters was developed using regression analysis which was used to predict the value of the grey relational grade using the optimal parameter levels.

  18. Development of API 5L X80 pipes by UOE process, using SAW (Submerged Arc Welding) welding; Desenvolvimento de tubos API 5L X80 pelo processo UOE, utilizando soldagem SAW (Submerged Arc Welding)

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Sergio S.; Roza, Juliana E. [Tenaris Confab, Pindamonhangaba, SP (Brazil)


    High strength API X80 grade pipe constitute a new class of product manufactured either by the TMCP or TMCR process, which aim to obtain high values of yield strength, tensile strength and good toughness required by line pipe specifications, which are becoming more rigorous everyday. High strength steels have many advantages, due to low overall project costs associated principally with reduced wall thickness causing low transport and pipe installation costs. X80 material can be used in Onshore and Offshore constructions. This paper deals with X80 material produced by TMCR and welded by the longitudinal SAW process (submerged arc welding) by TENARIS CONFAB. The material was characterized by conducting tensile and Charpy impact tests, hardness measurements and metallographic analysis. The mechanical properties and microstructural features of the material are discussed and the advantages of using X80 grade steels in offshore projects are highlighted. The results obtained were found to be in accordance with the requirements of API 5L Standard (2000), 42nd edition. (author)

  19. Numerical analysis on temperature field in single-wire flux-aided backing-submerged arc welding (United States)

    Pu, Juan; Wu, Ming Fang; Pan, Haichao


    Single-wire flux-aided backing-submerged arc welding (FAB-SAW) technology has been widely used to weld thick steel plate due to its easy assembly and high heat input. The microstructure and property of welded joint are closely related to the thermal field of FAB-SAW process. In this research, the feature of thermal field for single-wire FAB-SAW was investigated. Based on the heat transfer mechanism, a three-dimensional transient model for thermal field was developed based on the influence of steel thickness, groove angle and ceramic backing. The temperature profile in single-wire FAB-SAW of D36 steel under different welding conditions was simulated by ANSYS. The characteristic of thermal field was analyzed and the influences of groove angle on temperature field for different plate thicknesses were discussed. The calculated geometries and dimensions of weld cross-section under different conditions show a good agreement with the experimental results. This newly built model can describe the thermal field accurately, which would be helpful to understanding the thermophysical mechanism of FAB-SAW and optimizing the welding process.

  20. Thermal Behavior of an HSLA Steel and the Impact in Phase Transformation: Submerged Arc Welding (SAW) Process Approach to Pipelines (United States)

    Costa, P. S.; Reyes-Valdés, F. A.; Saldaña-Garcés, R.; Delgado, E. R.; Salinas-Rodríguez, A.

    Heat input during welding metal fusion generates different transformations, such as grain growth, hydrogen cracking, and the formation of brittle structures, generally associated with the heat-affected zone (HAZ). For this reason, it is very important to know the behavior of this area before welding. This paper presents a study of the thermal behavior and its effect on phase transformations in the HAZ, depending on cooling rates (0.1-200 °C/s) to obtain continuous cooling transformation (CCT) curves for an high-strength low-alloy (HSLA) steel. In order to determine the formed phases, optical microscopy and Vickers microhardness measurement were used. The experimental CCT curve was obtained from an HSLA steel, and the results showed that, with the used cooling conditions, the steel did not provide formation of brittle structures. Therefore, it is unlikely that welds made by submerged arc welding (SAW) may lead to hydrogen embrittlement in the HAZ, which is one of the biggest problems of cracking in gas conduction pipelines. In addition, with these results, it will be possible to control the microstructure to optimize the pipe fabrication with SAW process in industrial plants.

  1. Environmental cracking behavior of submerged arc-welded supermartensitic stainless steel weldments (United States)

    Srinivasan, P. Bala; Sharkawy, S. W.; Dietzel, W.


    Supermartensitic stainless steel welds produced by submerged are welding were assessed for their microstructure and properties. Slow strain rate tests conducted on these specimens revealed that both the parent material and the weld metals are susceptible to cracking under conditions of hydrogen (H) charging.


    Directory of Open Access Journals (Sweden)

    Erick de Sousa Marouço


    Full Text Available The present work is part of a research program that aims to evaluate the technical feasibility of increasing productivity in the manufacturing of tubular components for offshore oil industry, which are fully welded by automatic submerged arc welding process, with high heat input, but with no impairment on the impact toughness of the weld metal. Multipass welds were produced by the submerged arc welding process, with a combination of F7A4-EM12K (wire/flux, by using a 3.2 mm-diameter wire, preheating at 80°C, with direct current, in flat position, with heat input varying from 3.5 kJ/mm to 12 kJ/mm. After welding, tensile tests and Charpy-V impact tests at –60°C, –40°C, –20°C, 0°C and 20°C were carried out, as well as metallographic examination by both optical (OM and scanning electron microscopy (SEM, of specimens obtained entirely from the weld metal, allowing the discussion over the toughness X microstructure relationship. The weld metals have shown higher toughness levels in relation to the minimum required for use with low-alloy C-Mn steels welding with requirements of impact toughness of 27 J at 0°C for heat input up to 12 kJ/mm allowing an increase in productivity of 58% on the effective manufacturing time.

  3. 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


    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...... residual stresses. These stresses have a negative impact on the integrity of the welded joint as they promote distortion, reduce fatigue life, and contribute to corrosion cracking and premature failure in the weld components. This paper deals with the influence and impact of welding method on the welding...... induced residual stresses. It is also investigated whether the assumption of residual stresses up to yield strength magnitude are present in welded structures as stated in the design guidelines. The fatigue strength for welded joints is based on this assumption. The two welding methods investigated...

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


    Andreassen, Michael Joachim; Yu, Zhenzhen; Liu, Stephen; Guerrero-Mata, Martha Patricia


    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 residual stresses. These stresses have a negative impact on the integrity of the welded joint as they promote distortion, reduce fatigue life, and contribute to corrosion cracking and premature fail...

  5. Inclusions and Microstructure of Ce-Added Weld Metal Coarse Grain Heat-Affected Zone in Twin-Wire Submerged-Arc Welding (United States)

    Yu, S. F.; Yan, N.; Chen, Y.


    In high heat-input multi-pass twin-wire submerged-arc welding, weld metal of previous pass will be affected by the heat input of subsequent one and form coarse-grained heat-affected zone (CGHAZ). This study focused on the effects of welding thermal cycle on the inclusions and microstructure of Ce-alloyed weld metal CGHAZ. According to the study of inclusions and microstructure of weld metal CGHAZ, it was found that the composition and type of the inclusions did not change under the effect of welding thermal cycle. Although the inclusions were coarsened slightly, the promoting ability to acicular ferrite (AF) was not deprived after thermal cycling. There are three types of AF in weld metal CGHAZ, which include oxy-sulfides of Ce inclusions-promoted AF, home-position-precipitated AF, and sympathetic AF. Results showed more than 80% of microstructure was AF, which greatly benefited the mechanical properties of weld metal CGHAZ, even though granular bainite and M-A constituents were generated.

  6. A Study on the Application of Submerged Arc Welding for Thin Plate of A-Grade 3.2 Thickness Steel in Ship Structure (United States)

    Lee, Jeong-Soo; Yun, Jin-Oh; Lim, Dong-Yong; Jang, Yong-Won; Kim, Bong-Joon; Oh, Chong-In


    This paper is focused on application submerged arc welding process, which offers many advantages compared to conventional CO2 welding process, for thin plate in ship structure. For this purpose, optimized welding conditions are determined according to combination of wire & flux, relationship between welding parameters, bead shapes and mechanical tests such as tensile, bend and hardness. Also finite element(FE) based numerical simulation of thermal history and welding residual stress in welded joint of A-grade 3.2 thickness steel has been checked to qualitative tendency in this paper. In conclusion our company applied to this method in work piece and it was no problem. From the result of this study, it makes substantial saving of time and manufacturing cost and raises the welding quality of product.

  7. The Effect of Welding Parameters on Microstructural and Mechanical Properties of HSLA S960QL Type Steel with Submerged Arc Welding

    Directory of Open Access Journals (Sweden)

    Mehmet TÜRKER


    Full Text Available In this study, S960QL steels were welded with submerged arc welding process in order to examine microstructural and mechanical properties. For the microstructural investigation, microscopical examination methods were used for weld zones. Tensile, impact toughness and micro hardness tests were made for different samples obtained from the weld zone and the base metal. The examinations of fracture surfaces were made by using optical microscope and scanning electron microscope. The flat type tensile strength values were near to the base materials. Charpy impact toughness tests were made for the base metal, the weld metal center line, the fusion line, the zone between weld metal centerline and the fusion line. Impact energy of the weld metal was obtained lower than the base metal. The lowest impact energy was obtained at the fusion line. Heat affected zone had the highest value in micro hardness tests. In microstructure evaluation, the interface of the fusion zone-heat affected zone and heat affected zone had coarser grain structure than the base metal. Alloy carbides dissolved because of the high temperature values occurred at heat affected zone.

  8. The modeling of heat affected zone (HAZ in submerged arc welding (SAW surfacing steel element

    Directory of Open Access Journals (Sweden)

    J. Winczek


    Full Text Available In the work the bimodal heat source model in the description of the temperature field is presented. The electric arc was treated physically as one heat source, whose heat was divided: part of the heat is transferred by the direct impact of the electric arc, but another part of the heat is transferred to the weld by the melted material of the electrode. Computations of the temperature field during SAW surfacing of S355 steel element are carried out. The macrographic and metallographic analysis of the weld confirmed the depth and shapes of the fusion line and HAZ defined by the numerical simulation.

  9. Joining of Materials with Diferent Properties Through Submerged Arc Welding Process and Destructive and Non-Destructive Testing of the Joints

    Directory of Open Access Journals (Sweden)

    Yakup Kaya


    Full Text Available In this study, X60, X65 and X70 steels used in petroleum and natural gas pipeline were joined with Submerged Arc Welding by using different type of welding fluxes (LN761 and P223 and wires (S1 and S2Mo. Initially, visual and radiographic inspection techniques were subjected to welded joints for determining surface and subsurface defects. After that, spectral analyses were carried out in order to determine the compositions of wire-flux-base metal on the joints. Impact toughness test were performed for determining toughness properties the joints. Furthermore, hardness and microstructure studies were also carried out on the samples. As a result of the visual and radiographic inspection on the welded samples, there were no weld defects on joints were observed. It was clearly understood that carbon ratio in the compositions of weld metal higher than base metal but lower than filler metal in terms of spectral analyses results. According to impact toughness test results, the joints obtained by using S2Mo welding wire and P223 welding flux had better impact toughness value than the joints obtained by S1 welding wire and LN 761 welding flux. With respect to hardness test, the highest hardness values were measured on weld metal. When the microstructure images were examined, it is clearly understood that similar images for all the joints were shown adjacent zones to weld metals heat affected zones and welding boundary, due to heat input constant.

  10. The application of imperialist competitive algorithm for optimization of deposition rate in submerged arc welding process using TiO{sub 2} nano particle

    Energy Technology Data Exchange (ETDEWEB)

    Ghaderi, Mohammad Reza; Eslampanah, Amirhossein; Ghaderi, Kianoosh [Islamic Azad University, Sanandaj (Iran, Islamic Republic of); Aghakhani, Masood [Razi University, Kermanshah (Iran, Islamic Republic of)


    We used a novel optimization algorithm based on the imperialist competitive algorithm (ICA) to optimize the deposition rate in the submerged arc welding (SAW) process. This algorithm offers some advantages such as simplicity, accuracy and time saving. Experiments were conducted based on a five factor, five level rotatable central composite design (RCCD) to collect welding data for deposition rate as a function of welding current, arc voltage, contact tip to plate distance, welding speed and thickness of TiO{sub 2} nanoparticles coated on the plates of mild steel. Furthermore, regression equation for deposition rate was obtained using least squares method. The regression equation as the cost function was optimized using ICA. Ultimately, the levels of input variables to achieve maximum deposition rate were obtained using ICA. Computational results indicate that the proposed algorithm is quite effective and powerful in optimizing the cost function.

  11. Irradiation behavior of a submerged arc welding material with different copper content; Bestrahlungsverhalten einer UP-Versuchsschweissnaht mit unterschiedlichen Kupfergehalten

    Energy Technology Data Exchange (ETDEWEB)

    Langer, R. [Siemens AG Energieerzeugung KWU, Erlangen (Germany); Bartsch, R. [Kernkraftwerk Obrigheim GmbH (Germany)


    Che report presents results of an irradiation program on specimens of submerged arc weldings with copper contents of 0.14% up to 0.42% and a fluence up to 2.2E19 cm{sup -2} (E>1MeV). Unirradiated and irradiated tensile- Charpy-, K{sub lc}- and Pellini-specimens were tested of material with a copper content of 0.22%. On the other materials Charpy tests and tensile tests were performed. The irradiation of the specimens took place in the KWO - ``RPV, a PWR with low flux and in the VAK - RPV, a small BWR with high flux. - The irradiation induced embrittlemnt shows a copper dependence up to about 30%. The specimens with a copper content higher than 0.30% show no further embrittlement. Irradiation in different reactors with different flux (factor > 33) shows the same state of embrittlement. Determination of a K{sub lc}, T-curve with irradiated specimens is possible. The conservative of the RT{sub NDT} - concept could be confirmed by the results of Charpy-V, drop weight- and K{sub lc}-test results. [Deutsch] Zur zusaetzlichen Absicherung des KWO-RDB wurde Ende 1979 eine UP-Versuchsschweissnaht mit vergleichbarer chemischer Zusammensetzung und vergleibaren mechanisch-technologischen Werkstoffen im unbestrahlten Ausgangszustand wie die RDB Core-Rundnaht hergestellt. Teile der Naht wurden durch Verkupfern der Schweissdraehte auf unterschiedliche Gehalte von Cu=0,14% bis 0,42% eingestellt. Aus dieser Schweissverbindung wurden Proben im VAK und KWO-RDB bestrahlt. Im Rahmen der Aktivitaeten zur Absicherung des KWO-RDBs erfolgte 1995 die Pruefung der bestrahlten Proben. Die mechanisch technologischen Werkstoffwerte vor und nach Bestrahlung werden gegenuebergestellt und praesentiert. Mit dem Ergebnis wurde ein weiterer Nachweis fuer die Konservativitaet des RT{sub NDT}-Konzeptes erbracht. Es wurde nachgewiesen, dass fuer den untersuchten Bereich kein Dose-Rate Effekt bzw. Bestrahlungszeiteinfluss existiert. Fuer UP-Schweissungen mit den vorliegenden Fertigungsparametern und bei

  12. Pengaruh Perubahan Arus dan Kecepatan serta Kelembapan Flux Terhadap Hasil Impact dan Kekerasan serta Macrostructure Fillet Weld Hasil Pengelasan Submerged Arc Welding (SAW

    Directory of Open Access Journals (Sweden)

    Famessa Fitria Lestari


    Full Text Available Submerged Arc Welding (SAW adalah salah satu jenis pengelasan busur listrik elektroda terumpan (consumable electrode yang prosesnya berlangsung dalam rendaman flux. Hasil pengelasan menggunakan SAW yang baik akan didapatkan jika dilakukan pemilihan parameter arus dan kecepatan serta kelembapan flux yang tepat selama proses pengelasan. Pengelasan dilakukan dengan mesin SAW tipe S6TF F2 yang diproduksi oleh ESAB dengan posisi 1F sebanyak dua layer. Percobaan pertama, dilakukan dengan memvariasikan parameter arus dan kecepatan untuk menghasilkan heat input yang sama sedangkan potensial dibuat sama. Percobaan kedua, dilakukan dengan memvariasikan kecepatan sedangkan parameter lain dibuat konstan sehingga menghasilkan heat input yang berbeda. Sedangkan untuk percobaan ketiga, dilakukan dengan memvariasikan kelembapan. Dari pengujian didapatkan bahwa dengan memvariasikan arus dan kecepatan untuk mendapatkan heat input yang sama menghasilkan dimensi HAZ yang berbeda. Dengan menggunakan flux yang lembap, maka akan terbentuk cacat berupa porositas. Hasil uji impact didapat  impact stregth tertinggi pengelasan terdapat pada kecepatan 33 cm/min, arus 350 A dan kelembapan flux 0 %. Nilai kekerasan di daerah weld metal dan HAZ untuk seluruh specimen menunjukkan tipikal yang sama kecuali pada spesimen F2.

  13. Modeling and Analysis of the Weld Bead Geometry in Submerged Arc Welding by Using Adaptive Neurofuzzy Inference System

    Directory of Open Access Journals (Sweden)

    Nuri Akkas


    Full Text Available This study is aimed at obtaining a relationship between the values defining bead geometry and the welding parameters and also to select optimum welding parameters. For this reason, an experimental study has been realized. The welding parameters such as the arc current, arc voltage, and welding speed which have the most effect on bead geometry are considered, and the other parameters are held as constant. Four, three, and five different values for the arc current, the arc voltage, and welding speed are used, respectively. So, sixty samples made of St 52-3 material were prepared. The bead geometries of the samples are analyzed, and the thickness and penetration values of the weld bead are measured. Then, the relationship between the welding parameters is modeled by using artificial neural network (ANN and neurofuzzy system approach. Each model is checked for its adequacy by using test data which are selected from experimental results. Then, the models developed are compared with regard to accuracy. Also, the appropriate welding parameters values can be easily selected when the models improve.

  14. Investigation of the Effects of Submerged Arc Welding Process Parameters on the Mechanical Properties of Pressure Vessel Steel ASTM A283 Grade A

    Directory of Open Access Journals (Sweden)

    Prachya Peasura


    Full Text Available The pressure vessel steel is used in boilers and pressure vessel structure applications. This research studied the effects of submerged arc welding (SAW process parameters on the mechanical properties of this steel. The weld sample originated from ASTM A283 grade A sheet of 6.00-millimeter thickness. The welding sample was treated using SAW with the variation of three process factors. For the first factor, welding currents of 260, 270, and 280 amperes were investigated. The second factor assessed the travel speed, which was tested at both 10 and 11 millimeters/second. The third factor examined the voltage parameter, which was varied between 28 and 33 volts. Each welding condition was conducted randomly, and each condition was tested a total of three times, using full factorial design. The resulting materials were examined using tensile strength and hardness tests and were observed with optical microscopy (OM and scanning electron microscopy (SEM. The results showed that the welding current, voltage, and travel speed significantly affected the tensile strength and hardness (P value < 0.05. The optimum SAW parameters were 270 amperes, 33 volts, and 10 millimeters/second travel speed. High density and fine pearlite were discovered and resulted in increased material tensile strength and hardness.

  15. Effect of B2O3 containing fluxes on the microstructure and mechanical properties in submerged arc welded mild steel plates (United States)

    Gupta, P.; Roy, J.; Rai, R. N.; Prasada Rao, A. K.; Saha, S. C.


    This paper represents a study on the effect of B2O3 additions in fluxes on the microstructure and mechanical properties of the weld metal formed during Submerged Arc Welding of Mild Steel plates. Five fluxes with about 2.5, 5, 7.5, 10 and 12.5% B2O3 were used with a low carbon electrode. Welding process parameters were kept constant for all the conditions. The microstructure of weld metal for each flux consisted mainly of acicular ferrite, polygonal ferrite, grain boundary ferrites and equiaxed pearlite. It was noted that the Vicker's hardness value was a function of boron content and shows a mixed trend. Impact Energy and Tensile Strength were increased with the increase in boron content in welds this can be attributed to relation with the higher acicular ferrite percentage. However an optimum level of toughness and tensile strength was available with 7.5% and 5% of B2O3 respectively. A qualitative comparison has also be done with fresh flux by means of full metallography and mechanically.

  16. Advanced characterization techniques in understanding the roles of nickel in enhancing strength and toughness of submerged arc welding high strength low alloy steel multiple pass welds in the as-welded condition (United States)

    Sham, Kin-Ling

    Striving for higher strength along with higher toughness is a constant goal in material properties. Even though nickel is known as an effective alloying element in improving the resistance of a steel to impact fracture, it is not fully understood how nickel enhances toughness. It was the goal of this work to assist and further the understanding of how nickel enhanced toughness and maintained strength in particular for high strength low alloy (HSLA) steel submerged arc welding multiple pass welds in the as-welded condition. Using advanced analytical techniques such as electron backscatter diffraction, x-ray diffraction, electron microprobe, differential scanning calorimetry, and thermodynamic modeling software, the effect of nickel was studied with nickel varying from one to five wt. pct. in increments of one wt. pct. in a specific HSLA steel submerged arc welding multiple pass weldment. The test matrix of five different nickel compositions in the as-welded and stress-relieved condition was to meet the targeted mechanical properties with a yield strength greater than or equal to 85 ksi, a ultimate tensile strength greater than or equal to 105 ksi, and a nil ductility temperature less than or equal to -140 degrees F. Mechanical testing demonstrated that nickel content of three wt. pct and greater in the as-welded condition fulfilled the targeted mechanical properties. Therefore, one, three, and five wt. pct. nickel in the as-welded condition was further studied to determine the effect of nickel on primary solidification mode, nickel solute segregation, dendrite thickness, phase transformation temperatures, effective ferrite grain size, dislocation density and strain, grain misorientation distribution, and precipitates. From one to five wt. pct nickel content in the as-welded condition, the primary solidification was shown to change from primary delta-ferrite to primary austenite. The nickel partitioning coefficient increased and dendrite/cellular thickness was

  17. Predicting the combined effect of TiO{sub 2} nano-particles and welding input parameters on the hardness of melted zone in submerged arc welding by fuzzy logic

    Energy Technology Data Exchange (ETDEWEB)

    Aghakhani, Masood; Ghaderi, Mohammad Reza; Jalilian, Maziar Mahdipour; Derakhshan, Ali Ashraf [Razi University, Kermanshah (Iran, Islamic Republic of)


    Submerged arc welding (SAW) is a high-quality arc welding process used in heavy industries for welding thick plates. In this process, selecting appropriate values for the input parameters is required for high productivity and cost effectiveness. A very important weld quality characteristic affected by welding input parameters is the hardness of melted zone (HMZ). This paper reports the applicability of fuzzy logic (FL) to predict HMZ in the SAW process which is affected by the combined effect of TiO{sub 2} nano-particles and welding input parameters. The arc voltage, welding current, welding speed, contact tip-to-plate distance, and TiO{sub 2} nano-particles were used as input parameters and HMZ as the response to develop FL model. A five-level five-factor central composite rotatable design (CCRD) was used in the experiments to generate experimental data. Experiments were performed, and HMZs were measured. The predicted results from FL were compared with the experimental data. The correlation factor value obtained was 99.99% between the measured and predicted values of HMZ. The results showed that FL is an accurate and reliable technique for predicting HMZ because of its low error rate.

  18. Static and dynamic fracture toughness of 25mm thick single edge notch bend (SENB) specimen of C-Mn pressure vessel submerged arc weld metal and flaw assessment under dynamic loading (United States)

    Xu, W.; Wiesner, C. S.


    Although there are well established procedures for assessing the significance of defects in welded structures in a number of countries, such as BS7910 and R6 procedures in the UK, the Japanese WES 2807 procedure, the API and MPC procedures in the USA and the recently completed SINT AP procedure resulting from European collaboration, there are no clear guidelines for assessment of the effects of dynamic loading. In principle, the standard procedure can be applied for any rate of loading but there is little or no experience of how to allow for the effects of dynamic loading on load magnitude and material properties. Submerge arc weldments of 100mm thick have been manufactured. The effect of loading rate was investigated by testing 25mm thick SENB specimens. The fracture toughness of the weld metal exhibited marked loading rate sensitivity; shift in fracture toughness transition temperature for high loading rate tests of up to 115^{circ}C for 25mm specimens. Finite element (FE) analyses have been carried out to obtain plastic collapse load solutions for SENB fracture mechanics test piece. A simple equation for estimate of dynamic plastic yielding load has been suggested. Flaw assessment under dynamic loading has been demonstrated using the results of dynamic fracture toughness and plastic yiending load. The general methods of assessment of the significance of defects in BS7910 is shown to be applicable to assessments under dynamic loading up to impact.

  19. Estudo microestrutural de aço carbono soldado com o processo arco submerso e adições de Fe-Ti Microstructural study of carbon steel welded with the submerged arc process and additions of Fe-Ti

    Directory of Open Access Journals (Sweden)

    Aleir Fontana de Paris


    Full Text Available Os cordões de solda apresentam normalmente uma estrutura colunar grosseira, o que diminui as propriedades mecânicas do conjunto soldado. No caso da soldagem com arco submerso, o emprego de alta energia proporciona uma solda com características peculiares como a elevada taxa de fusão e consequentemente grande volume de metal fundido. Foi comprovado que a redução no tamanho e/ou modificações na forma dos cristais obtidos aumenta a tenacidade da junta soldada. Estudos realizados mostraram que a adição de titânio, até certo limite, modificaria a microestrutura obtida bem como o tamanho dos grãos solidificados. Neste trabalho, foi empregada uma liga metálica de Fe-Ti adicionada no momento de soldagem, tipo bead-on-plate, sobre aço estrutural ASTM A 36, com espessura de 10 mm. As adições de titânio variaram entre 0,48 ppm e 29,1 ppm, e a soldagem foi executada com uma energia de 1170 kJ/m. Os resultados mostraram modificações da fase ferrita acicular bem como da ferrita poligonal presentes na solda.The welds usually have a coarse columnar structure, which reduces the mechanical properties of welded assembly. In the case of submerged arc welding, the use of high-energy provides a weld with specific characteristics such as high melting rate and consequently a large volume of molten metal. It was established that the reduction in size and/or changes in the shape of the crystals obtained increases the toughness of the weld. Studies have shown that the addition of titanium to a certain limit, modify the microstructure obtained and the size of the grains solidified. In this study, we used an alloy of Fe-Ti added at the time of welding-type bead-on-plate on structural steel ASTM A 36 with a thickness of 10 mm. The additions of titanium ranged between 0.48 ppm and 29.1 ppm, and welding was performed with an energy of 1170 kJ/m The results showed changes in the phase acicular ferrite and polygonal ferrite present in the weld.


    Directory of Open Access Journals (Sweden)

    Kiryanto Kiryanto


    Full Text Available In this of globalization is growing very rapidly advancing technology. As well as in shipyard industry is toshipbuilding process. Submerged Arch Welding (SAW is as joint methode of ship construction. Purpose ofresearch know number of electrodes wich requirement on block welding the ship DCV 18500 DWT in JasaMarina Indah Shipyard Semarang.The specimen experiment used is ST 42 low carbon steel. Variation of plates tickness is 12, 13, 14, 17, 19 and24 mm. Research step is carried out by making the specimen with variation thickness respectively. Specimendimensions length x width is 500 mm x 50 mm. The number of each specimen was made of three pieces. Thendo the measurement welding length, length and weight electrodes and slag welding.The analysis result of data welding on the specimen can be known number of electrode s and fluxs inSubmerged Arch Welding (SAW. The aplication of this research is the block DB 5(p/c/s, SS5A(p/s, SS5B(p/s, UD 5C, and TB 102 (p/c/s. Weight of consumable electrodes is 2185.31 kg (73 roll and number offlux used wight is 2967.95 kg (119 bag.

  1. Survey of welding processes. (United States)


    The current KYTC SPECIAL PROVISION NO. 4 WELDING STEEL BRIDGES prohibits the use of welding processes other than shielded metal arc welding (SMAW) and submerged arc welding (SAW). Nationally, bridge welding is codified under ANSI/AASHTO/AWS D1....

  2. effect of post-weld heat treatment on the microstructure

    African Journals Online (AJOL)


    among others are shielded metal arc welding, submerge arc welding, gas metal arc welding, plasma arc welding, gas ... welding (SMAW) technique is preferable to the other techniques ..... studies''International Journal of Innovative Research.

  3. New Tendencies in Development of Carbonaceous Additives for Welding Fluxes (United States)

    Kozyrev, N. A.; Kryukov, R. E.; Kozyreva, O. A.


    The paper provides results of comparative analysis of the effect of carbonaceous components introduced into welding fluxes on molten metal - slag interaction. Thermodynamical calculations of dehydrogenization are presented for submerged arc welding. A positive influence of carbonaceous additives on gas content and mechanical properties of welds is demonstrated. Carbon and fluorine containing additives are emphasized to be promising for automatic submerged arc welding.

  4. The use of submerged-arc welding flux slag as raw material for the fabrication of multiple-use mortars and bricks Uso de escória de fluxo de soldagem a arco submerso como matéria-prima para a fabricação de argamassas de múltiplo uso e tijolos

    Directory of Open Access Journals (Sweden)

    Caroline Espinosa Viana


    Full Text Available This work has as objective to analyze the recycling possible uses of the slag of welding flux (SWF in the civil construction. It was searched the liability of SWF as substitute of sand in the production of multiple-use mortars and clay for the production of ceramic bricks. SWF has origin in the submerged-arc welding (SAW, and have been used slags of the acid, neutral and basic types, according to its neutrality. Mortars have been made containing the three types of SWF and in addition a reference mortar made with sand. Physical and mineralogical characteristics of each SWF were studied, and the physical properties (consistency and density and mechanical properties (compressive and tensile strengths of the mortars were analyzed. Ceramic pieces have been made containing kaolinitic sedimentary clay up to 10 wt. % of SWF. The pieces were prepared by uniaxial pressing and fired at 950ºC. The following properties after firing were determined: linear shrinkage, water absorption, apparent porosity, apparent density, and flexural strength. The results show that for multiple-use mortars, SWF reached excellent results, being an overall substitute for sand as fine aggregate. For ceramic bricks, SWF can also be used as partial substitute for red clay. Both applications of SWF significantly contributes for the reduction of the ambient impact: on one hand, reducing the extraction of natural sand and clay, on other hand, contributing for the reduction of the risk of ground water contamination due to the inadequate disposal of the SWF.Este trabalho tem como objetivo avaliar possíveis usos para a reciclagem da escória de fluxo de soldagem (EFS na construção civil. Foi pesquisada a possibilidade do uso da EFS como substituto da areia na produção de argamassas de múltiplo-uso e substituição da argila na produção de tijolos. A EFS tem origem na soldagem a arco submerso (SAS, e foram usadas escórias dos tipos ácida, neutra e básica, conforme sua

  5. The geometry of the strip electrode used in the process of submerged arc hardfacing of continuous casting rolls

    Directory of Open Access Journals (Sweden)

    Леонід Кімович Лещинськiй


    Full Text Available The results of the investigation of the influence of the size of the strip electrode on the dilution of the base metal used in the process of submerged arc hardfacing of continuous casting rolls are presented. Increasing the thickness and decreasing the width of the strip electrode (60´0,5 mm, 45´0,7 mm, 30´1,0 mm results in the changing of the shape and dimensions of the fusion zone of the base metal to enhance the depth and reduce the non-uniformity of fusion penetration. The experimental data show that the dilution ratio of the base metal using the strip electrode 45´0,7 mm, containing 13,5 % chromium, made it possible to obtain more than 11 % chromium in the chemical composition of the third deposited layer. In the process of submerged arc hardfacing increasing the travel speed of the strip electrode (heat source up to 12 m/hour enhance the dilution ratio of the base metal. Despite this, the chromium content of the third layer is not less than 11 %. At the same time, the improved parameters of the hardfacing process allowed to achieve the better weld shape and to reduce the number of welding defects. When deposited on continuous casting rolls, the chemical composition of the deposited metal insures the corrosion resistance of the rolls and increases their longevity

  6. Caracterização e avaliação da resistência à corrosão na soldagem de tubulação de aço inoxidável duplex UNS S31803 pelo processo a arco submerso Characterization and evaluation of corrosion resistance of welded joint of duplex stainless steel pipe UNS S31803 by submerged arc process

    Directory of Open Access Journals (Sweden)

    Juan Manuel Pardal


    Full Text Available O presente trabalho apresenta os resultados da caracterização e avaliação da resistência à corrosão de uma junta soldada correspondente a uma tubulação de aço inoxidável duplex (AID UNS S31803 de 35 mm de espessura de parede soldada pelos processos de soldagem TIG (GTAW na raiz e arco submerso (SAW no enchimento e acabamento. Foram empregados como consumíveis de soldagem metais de adição de liga 25Cr-9Ni-4Mo (% em peso. Os resultados da caracterização das propriedades mecânicas, composição química e resistência à corrosão em diversas regiões da junta soldada foram comparados com os obtidos para o metal de base da tubulação, assim como com os valores mínimos exigidos pelas normas de projeto. Os resultados obtidos demonstram claramente a possibilidade da implementação do processo SAW na pré fabricação de tubulações de paredes espessas de AID, tendo em vista os resultados das propriedades analisadas e a grande demanda na construção e montagem de tubulações desta família de aço inoxidáveis na indústria offshore.This work presents the mechanical properties, microstructural and corrosion resistance evaluation of a welded joint of duplex stainless steel (DSS pipe with 35 mm wall thickness. The joint was welded by gas tungsten arc welding (GTAW process in the root passes and submerged arc welding (SAW in the filling and cap passes using filler metals with composition 25Cr-9Ni-4Mo (%wt.. The results of mechanical properties, chemical composition and corrosion resistance characterization in different regions of the welded joint were compared to the base metal and to the specifications required by the standards applied in the project. The main focus of this work was to show the successful utilization of SAW process in the welding of thick wall pipes of DSS. The application of high productivity process such as SAW has a crescent demand in offshore industry.

  7. Process Modeling and Optimization of a Submerged Arc Furnace for Phosphorus Production

    NARCIS (Netherlands)

    Scheepers, E.; Yang, Y.; Adema, A.T.; Boom, R.; Reuter, M.A.


    This article presents a process model of a phosphorus-producing, submerged arc furnace. The model successfully incorporates accurate, multifield thermodynamic, kinetic, and industrial data with computational flow dynamic calculations and thus further unifies the sciences of kinetics and equilibrium

  8. In-Situ Nondestructive Examination of Weld Penetration

    National Research Council Canada - National Science Library

    Chin, Bryan


    The objective of this program is to develop infrared sensing techniques to monitor and control welding penetration in gas tungsten arc and submerged arc welding processes used by the US Navy in the construction of ships...

  9. Fingerprint of a submerged-arc furnace : Optimising energy consumption through data mining, dynamic modelling and computational fluid dynamics

    NARCIS (Netherlands)

    Scheepers, E.


    This study imparts a scientific perception of a phosphorous-producing submerged arc furnace never seen before; a proverbial fingerprint that can improve problem identification, disturbance diagnostics, process prediction, dynamic modelling and model predictive control of this type of furnace. It

  10. Mechanical Characteristics of Submerged Arc Weldment in API Gas Pipeline Steel of Grade X65 (United States)

    Hashemi, S. H.; Mohammadyani, D.


    The mechanical properties of submerged arc weldment (SAW) in gas transportation pipeline steel of grade API X65 (65 ksi yield strength) were investigated. This steel is produced by thermo mechanical control rolled (TMC), and is largely used in Iran gas piping systems and networks. The results from laboratory study on three different regions; i.e. base metal (BM), fusion zone (FZ) and heat affected zone (HAZ) were used to compare weldment mechanical characteristics with those specified by API 5L (revision 2004) standard code. Different laboratory experiments were conducted on test specimens taken from 48 inch outside diameter and 14.3 mm wall thickness gas pipeline. The test results showed a gradient of microstructure and Vickers hardness data from the centerline of FZ towards the unaffected MB. Similarly, lower Charpy absorbed energy (compared to BM) was observed in the FZ impact specimens. Despite this, the API specifications were fulfilled in three tested zones, ensuring pipeline structural integrity under working conditions.

  11. Dissipation of Electrical Energy in Submerged Arc Furnaces Producing Silicomanganese and High-Carbon Ferromanganese (United States)

    Steenkamp, Joalet Dalene; Hockaday, Christopher James; Gous, Johan Petrus; Nzima, Thabo Witness


    Submerged-arc furnace technology is applied in the primary production of ferroalloys. Electrical energy is dissipated to the process via a combination of arcing and resistive heating. In processes where a crater forms between the charge zone and the reaction zone, electrical energy is dissipated mainly through arcing, e.g., in coke-bed based processes, through resistive heating. Plant-based measurements from a device called "Arcmon" indicated that in silicomanganese (SiMn) production, at times up to 15% of the electrical energy used is transferred by arcing, 30% in high-carbon ferromanganese (HCFeMn) production, compared with 5% in ferrochromium and 60% in ferrosilicon production. On average, the arcing is much less at 3% in SiMn and 5% in HCFeMn production.

  12. Welding processes handbook

    CERN Document Server

    Weman, Klas


    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...

  13. Low temperature friction stir welding of P91 steel


    Kalvala, Prasad Rao; Akram, Javed; Misra, Mano; Ramachandran, Damodaram; Gabbita, Janaki Ram


    Bead-on-plate friction stir welds were made on P91 alloy with low and high rotational speeds (100 and 1000 RPM) to study their effects on weld microstructural changes and impression creep behavior. Temperatures experienced by the stir zone were recorded at the weld tool tip. Different zones of welds were characterized for their microstructural changes, hardness and creep behavior (by impression creep tests). The results were compared with submerged arc fusion weld. Studies revealed that the s...

  14. Some Aspects of Oxidation-Reduction Reactions under Carbon-Bearing Flux Welding (United States)

    Kryukov, R. E.; Kozyrev, N. A.; Galevsky, G. V.; Bendre, Y. V.; Goryushkin, V. F.; Valuev, D. V.


    The authors have completed thermodynamic calculations of oxidation-reduction processes under submerged arc welding with application of carbon containing additive. The calculations have shown that carbon, due to its high reducing properties under T = 1950 - 2200 K, introduced into the system can significantly decrease the amount of non-metallic inclusions in the weld metal and so improve its mechanical properties.

  15. Improvement of Energy and Materials Efficiencies by Introducing Multiple-Wire Welding

    Directory of Open Access Journals (Sweden)

    Bajcer, B.


    Full Text Available The paper deals with a study and comparison between welding with several wires in different shielding atmospheres and single-wire welding. The first part treats the equipment for multiple-wire electrode welding and a comparison between single-wire welding and twin-wire welding. The second part deals with the melting rate as a basis for determining the productivity of welding processes, and the third one with the energy efficiency as a criterion of cost-effectiveness of welding. Some results obtained regarding strength of submerged arc welded joints are shown.

  16. HSSI Monthly Letter Status Report for (W6953) December 2000.

    Energy Technology Data Exchange (ETDEWEB)

    Rosseel, T.M.


    This report is issued monthly by the staff of the Heavy-Section Steel Irradiation (HSSI) Program (JCN:W6953) to provide the Nuclear Regulatory Commission (NRC) staff with summaries of technical highlights, important issues, and financial and milestone status within the program. This report gives information on several topics corresponding to events during the reporting month: (1) overall project objective, (2) technical activities, (3) meetings and trips, (4) publications and presentations, (5) property acquired, (6) problem areas, and (7) plans for the next reporting period. Next the report gives a breakdown of overall program costs as well as cost summaries and earned-value-based estimates for performance for the total program and for each of the eight program tasks. The seven tasks correspond to the 189, dated March 23, 1998, and modified by the inclusion of the former ''Embrittlement Data Base and Dosimetry Evaluation'' Program, JCN 6164 in March, 1999. The final part of the report provides financial status for all tasks and status reports for selected milestones within each task. The task milestones address the period from April 1998 to December 2000, while the individual task budgets address the period from October 1999 to December 2000. Beginning in October, 1992, the monthly business calendar of the Oak Ridge National Laboratory was changed and no longer coincides with the Gregorian/Julian calendar. The business month now ends earlier than the last day of the calendar month to allow adequate time for processing required financial reports to the Department of Energy. The precise reporting period for each month is indicated on the financial and milestone charts by including the exact start and finish dates for the current business month.

  17. New materials for welding and surfacing (United States)

    Kozyrev, N. A.; Galevsky, G. V.; Kryukov, R. E.; Titova, D. A.; Shurupov, V. M.


    The paper provides description of research into the influence of new materials and technologies on quality parameters of welds and deposited metal carried out in the research and production centre “Welding processes and technologies”. New welding technologies of tanks for northern conditions are considered, as well as technologies of submerged arc welding involving fluxing agents AN - 348, AN - 60, AN - 67, OK.10.71 and carbon-fluorine containing additives; new flux cored wires and surfacing technologies, teaching programs and a trainer for welders are designed.

  18. Friction Stir Welding of HT9 Ferritic-Martensitic Steel: An Assessment of Microstructure and Properties (United States)


    May 2007. [36] P. J. Konkol and M. F. Mruczek, ―Comparison of Friction Stir Weldments and Submerged Arc Weldments in HSLA-65 Steel,‖ Welding ... WELDING OF HT9 FERRITIC- MARTENSITIC STEEL: AN ASSESSMENT OF MICROSTRUCTURE AND PROPERTIES by Lara L. Ray June 2013 Thesis Advisor: Luke N...2013 3. REPORT TYPE AND DATES COVERED Master‘s Thesis 4. TITLE AND SUBTITLE FRICTION STIR WELDING OF HT9 FERRITIC-MARTENSITIC STEEL: AN

  19. Critical Analysis of Moving Heat Source Shape for ARC Welding Process of High Deposition Rate

    Czech Academy of Sciences Publication Activity Database

    Ghosh, A.; Hloch, Sergej; Chattopadhyaya, S.


    Roč. 21, č. 1 (2014), s. 95-98 ISSN 1330-3651 Institutional support: RVO:68145535 Keywords : Gaussian heat distribution * oval heat source shape * Submerged Arc Welding Subject RIV: JQ - Machines ; Tools Impact factor: 0.579, year: 2014

  20. On the use of slag from silicomanganese production for welding flux manufacturing (United States)

    Kozyrev, N. A.; Kryukov, R. E.; Lipatova, U. I.; Kozyreva, O. E.


    The technologies for manufacturing of welding fluxes with the use of slag from silicomanganese production and dust of gas purification from aluminum production are developed. The new compositions and production technology of welding fluxes are offered. The comparative evaluation of the new compositions and widely used AN-348 flux is provided. It is shown that the quality of submerged arc welding with the use of the developed flux composition is significantly better than the submerged arc welding with AN-348 flux. The effect of fractional composition on high-quality performance of the weld is investigated. The macro- and microstructures, nonmetallic inclusions and the mechanical properties of the weld are examined. It is shown that the introduction of carbon-fluorine containing additive into the flux, based on the dust of gas purification from aluminum production, can significantly improve the whole complex of mechanical properties of the weld, especially characteristics of impact hardness at low temperatures. The conducted research served as a basis for development of submerged arc welding technologies protected by the patents of the Russian Federation.

  1. Fatigue crack growth behavior of pressure vessel steels and submerged arc weldments in a high-temperature pressurized water environment (United States)

    Liaw, P. K.; Logsdon, W. A.; Begley, J. A.


    The fatigue crack growth rate (FCGR) properties of SA508 C1 2a and SA533 Gr A C1 2 pressure vessel steels and the corresponding automatic submerged are weldments were developed in a high-temperature pressurized water (HPW) environment at 288 °C (550°F) and 7.2 MPa (1044 psi) at load ratios of 0.02 and 0.50. The HPW enviromment FCGR properties of these pressure vessel steels and submerged arc weldments were generally conservative, compared with the approrpriate American Society of Mechanical Engineers (ASME) Section XI water environmental reference curve. The growth rate of fatigue cracks in the base materials, however, was considerably faster in the HPW environment than in a corresponding 288°C (550°F) base line air environment. The growth rate of fatigue cracks in the two submerged are weldments was also accelerated in the HPW environment but to a significantly lesser degree than that demonstrated by the corresponding base materials. In the air environment, fatigue striations were observed, independent of material and load ratio, while in the HPW environment, some intergranular facets were present. The greater environmental effect on crack growth rates displayed by the base materials, as compared with the weldments, was attributed to a different sulfide composition and morphology.

  2. Development of New Materials and Technologies for Welding and Surfacing at Research and Production Center "Welding Processes and Technologies" (United States)

    Kozyrev, N. A.; Kryukov, R. E.; Galevsky, G. V.; Titov, D. A.; Shurupov, V. M.


    The paper provides description of research into the influence of new materials and technologies on quality parameters of welds and added metal carried out at research and production center «Welding processes and technologies». New welding technologies of tanks for northern conditions are considered, as well as technologies of submerged arc welding involving fluxing agents AN - 348, AN - 60, AN - 67, OK. 10.71 and carbon-fluorine containing additives, new flux cored wires and surfacing technologies, teaching programs and a trainer for welders are designed.

  3. High quality and efficiency arc welding for steel frames of high-rise buildings; Chokoso biru tekkotsumuke kohinshitsu koseino yosetsu gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Kurehashi, T.; Taniyama, N.; Nakanishi, Y.; Katayama, N. [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)


    High current density narrow gap submerged arc welding method has been developed, high in quality and efficiency, for the preparation of steel frames for high-rise buildings. The conventional method is a heavy current, great heat input welding method using plural large-diameter wires. It demands huge facilities for power supply whose installation and management are quite complicated, and often gives rise to the anxiety that the produced weld may be defective, contain cracks, or reduced in toughness. In the method introduced here, the time-proved submerged arc welding method is applied to all the layers. In the newly developed high current density submerged arc welding technology, deep penetration and rich deposition protect toughness from deterioration, the quantity of input heat can be limited without lowering efficiency, and gaps can be made narrower for a reduction in the gap area. Penetration shapes are stable, welding heat input is appropriately specified for each welding pass, and fluctuation is reduced in the welding current and voltage. Thanks to heat input conditioned for each welding pass, welds are excellent in quality. The slag is easier to peel off, and incurs less defects, and the high melting speed results in excellent joint performance. 6 refs., 7 figs., 3 tabs.

  4. Application of Expectation Maximization Method for Purchase Decision-Making Support in Welding Branch

    Directory of Open Access Journals (Sweden)

    Kujawińska Agnieszka


    Full Text Available The article presents a study of applying the proposed method of cluster analysis to support purchasing decisions in the welding industry. The authors analyze the usefulness of the non-hierarchical method, Expectation Maximization (EM, in the selection of material (212 combinations of flux and wire melt for the SAW (Submerged Arc Welding method process. The proposed approach to cluster analysis is proved as useful in supporting purchase decisions.


    Directory of Open Access Journals (Sweden)

    Teguh Endah Saraswati


    Full Text Available Synthesis of iron oxide nanoparticles modified with carbon has been successfully performed by submerged arc-discharge method in ethanol/urea medium. Iron oxide used in the fabrication process was prepared by iron electrolysis in an electrolyte solution of NaCl. Fabrication of nanoparticles in this method uses two graphite electrodes. One of them was made in a pointed shape and the other graphite electrodes hollowed out and filled with a mixture of iron oxide, graphite and glue silica (as binder with a ratio of 1:3:1 (w/w/w. The liquid medium used in this method is a mixture solution of ethanol 50% and urea (0%, 10%, 25% and 50% with a volume ratio of 1:1 (v/v. The crystalline of iron oxide was characterized using X-Ray Diffraction (XRD, compared to JCPDS No. 89-0597, No. 89-0691 and No. 39-1346. Variations in the urea concentration in the liquid medium provided the changes of the surface character of the synthesized nanoparticles. The changes of surface character were analyzed by the Fourier Transform Infra Red (FTIR spectra and nanoparticle dispersion in water and ethanol. FTIR spectra showed the absorption of Fe-O, CH, CN, C = O, OH and NH at 460-555 cm-1, 650-1000 cm-1, 1000-1350 cm-1, 1640-1680 cm-1, 2400-3400 cm-1, 3200-3400 cm-1, 3100-3500 cm-1, respectively. The best hydrophilic surface character achieved when the nanoparticle was synthesized in medium of ethanol 50% with the addition of urea50%. The existence of a functional group attached on the surface of nanoparticles synthesized in ethanol/urea makes these nanoparticles had better dispersion than nanoparticles synthesized in ethanol medium without urea addition.

  6. Welding. (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…

  7. An analysis of the joints’ properties of thick-grained steel welded by the SAW and ESW methods

    Directory of Open Access Journals (Sweden)

    Krawczyk R.


    Full Text Available The article presents an analysis of properties of welded joints of thick-grained steel of P460NH type used more and more often in the modern constructions. A process of examining a technology of welding has been carried out on the thick-walled butt joints of sheet metal by two methods of welding namely submerged arc welding (SAW - 121 and electroslag (ESW - 722. The article deals with a topic of optimizing a process of welding thick-walled welded joints of fine-grained steel due to their mechanical properties and efficiency.

  8. Control of Softening Processes in the Heat-Affected Zone During Welding of High-Strength Steels (United States)

    Efimenko, L. A.; Kapustin, O. E.; Ramus', A. A.; Ramus', R. O.


    The hardness and the structure of the heat-affected zone (HAZ) under welding of tube steels of strength category K60 - K70 are studied. The steels are treated by regimes imitating the thermal cycles of different welding processes applied to tubes starting with manual arc welding and ending with energy-intensive automatic submerged-arc welding. The welding modes causing maximum decrease in the hardness of HAZ regions are determined. The conditions preventing softening under one-pass and multipass welding of high-strength steels are presented.

  9. Experimental investigation of the thickness effect for large as-welded SAW S355 steel specimens

    DEFF Research Database (Denmark)

    Ólafsson, Ólafur Magnús; Jensen, Jørgen Juncher; Berggreen, Christian


    The presented work aims to investigate and establish a pre-cise, thorough and detailed database from series of experi-mental testing of submerged arc welded (SAW) specimens of various thicknesses typically applied in ships and offshore structures and foundations. Welded structures of all sizes...... and shapes exhibit fatigue failure primarily in the welded region, rather than in the base material, due to imperfections and flaws relating to the welding procedure. The welded region has therefore received much attention from universities, re-search institutions along with industry as it is of significant...

  10. Secondary ledeburite formation during various welding techniques

    Directory of Open Access Journals (Sweden)

    Tonkovič M.P.


    Full Text Available The occurrence and formation sequence of secondary ledeburite in the heat affected zone of chromium ledeburitic tool steel W.Nr. 1.2379 (OCR12 VM after welding with SAW, TIG, microplasma and laser welding techniques is presented in this paper. Special attention was paid on the behaviour of carbides. The occurrence of secondary ledeburite is a result of local enrichment of the austenite matrix with alloying elements, due to partial or complete dissolution of primary/eutectic carbides. The results show that the largest amount of secondary ledeburite is formed during submerged arc welding, followed by TIG and microplasma welding technique. Welding by laser technique, with appropriate technological parameters, could prevent secondary ledeburite formation.

  11. Optimization of welding parameters for gas transportation steel pipes

    Directory of Open Access Journals (Sweden)

    S. Cvetkovski


    Full Text Available The aim of this paper is to define optimization of welding conditions for Submerged Arc Welding (SAW of steel pipes for gas transportation. Fine grain steel X-52 with thickness of 8 mm were used as a base material. Welding was performed from inner and outer side. Two wires, inclined under different angles, were feed separately. Eleven samples divided in three series were experimentally welded. Performed investigations indicated that the best properties showed weldments from series III, welded with the highest heat input. On the contrary of our expectations, welds from series II, using self made equipment, showed pretty bead properties and improper geometry. So, improving of this this equipment and obtaining welds with better properties is the target in future investigations.

  12. Low temperature friction stir welding of P91 steel

    Directory of Open Access Journals (Sweden)

    Prasad Rao Kalvala


    Full Text Available Bead-on-plate friction stir welds were made on P91 alloy with low and high rotational speeds (100 and 1000 RPM to study their effects on weld microstructural changes and impression creep behavior. Temperatures experienced by the stir zone were recorded at the weld tool tip. Different zones of welds were characterized for their microstructural changes, hardness and creep behavior (by impression creep tests. The results were compared with submerged arc fusion weld. Studies revealed that the stir zone temperature with 100 RPM was well below Ac1 temperature of P91 steel while it was above Ac3 with 1000 RPM. The results suggest that the microstructural degradation in P91 welds can be controlled by low temperature friction stir welding technique.

  13. Multi Objective Optimization of Weld Parameters of Boiler Steel Using Fuzzy Based Desirability Function

    Directory of Open Access Journals (Sweden)

    M. Satheesh


    Full Text Available The high pressure differential across the wall of pressure vessels is potentially dangerous and has caused many fatal accidents in the history of their development and operation. For this reason the structural integrity of weldments is critical to the performance of pressure vessels. In recent years much research has been conducted to the study of variations in welding parameters and consumables on the mechanical properties of pressure vessel steel weldments to optimize weld integrity and ensure pressure vessels are safe. The quality of weld is a very important working aspect for the manufacturing and construction industries. Because of high quality and reliability, Submerged Arc Welding (SAW is one of the chief metal joining processes employed in industry. This paper addresses the application of desirability function approach combined with fuzzy logic analysis to optimize the multiple quality characteristics (bead reinforcement, bead width, bead penetration and dilution of submerged arc welding process parameters of SA 516 Grade 70 steels(boiler steel. Experiments were conducted using Taguchi’s L27 orthogonal array with varying the weld parameters of welding current, arc voltage, welding speed and electrode stickout. By analyzing the response table and response graph of the fuzzy reasoning grade, optimal parameters were obtained. Solutions from this method can be useful for pressure vessel manufacturers and operators to search an optimal solution of welding condition.

  14. Study of verification and validation of standard welding procedure specifications guidelines for API 5L X-70 grade line pipe welding

    Directory of Open Access Journals (Sweden)

    Qazi H. A. A.


    Full Text Available Verification and validation of welding procedure specifications for X-70 grade line pipe welding was performed as per clause 8.2, Annexure B and D of API 5L, 45th Edition to check weld integrity in its future application conditions. Hot rolled coils were imported from China, de-coiling, strip edge milling, three roller bending to from pipe, inside and outside submerged arc welding of pipe, online ultrasonic testing of weld, HAZ and pipe body, cutting at fixed random length of pipe, visual inspection of pipe, Fluoroscopic inspection of pipe, welding procedure qualification test pieces marking at weld portion of the pipe, tensile testing, guided bend testing, CVN Impact testing were performed. Detailed study was conducted to explore possible explanations and variation in mechanical properties, WPS is examined and qualified as per API 5L 45th Edition.

  15. Welding. (United States)

    Cowan, Earl; And Others

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

  16. Fracture toughness of weld metal samples removed from a decommissioned Magnox reactor pressure vessel

    Energy Technology Data Exchange (ETDEWEB)

    Bolton, C.J.; Bischler, P.J.E.; Wootton, M.R.; Moskovic, R.; Morri, J.R.; Pegg, H.C.; Haines, A.B.; Smith, R.F.; Woodman, R


    Submerged-arc welds in Magnox RPVs are expected to show substantial shifts in ductile-to-brittle transition temperature (DBTT), due to their high copper content, and also because of a contribution from intergranular fracture. For structural integrity arguments, the fracture toughness of irradiated welds is predicted by applying an irradiation shift in DBTT to a start-of-life toughness curve. The shift is obtained from a trend curve derived from Charpy impact data. An uncertainty allowance is obtained by combining uncertainty contributions in start-of-life fracture toughness and shifts, including a contribution from uncertainties in neutron dose. Through-thickness samples were removed from four submerged-arc welds in a decommissioned Magnox RPV at Trawsfynydd. Fracture toughness tests were made on pre-cracked Charpy geometry specimens made from the samples, in order to compare the measured toughnesses with those predicted for irradiated material. Specimens were tested from several positions along the welds and also at four different through-thickness locations with dpa doses varying by a factor of more than 2. The paper presents the results of nearly 400 toughness measurements and demonstrates that the prediction methodology is sound.

  17. Numerical aspects for efficient welding computational mechanics

    Directory of Open Access Journals (Sweden)

    Aburuga Tarek Kh.S.


    Full Text Available The effect of the residual stresses and strains is one of the most important parameter in the structure integrity assessment. A finite element model is constructed in order to simulate the multi passes mismatched submerged arc welding SAW which used in the welded tensile test specimen. Sequentially coupled thermal mechanical analysis is done by using ABAQUS software for calculating the residual stresses and distortion due to welding. In this work, three main issues were studied in order to reduce the time consuming during welding simulation which is the major problem in the computational welding mechanics (CWM. The first issue is dimensionality of the problem. Both two- and three-dimensional models are constructed for the same analysis type, shell element for two dimension simulation shows good performance comparing with brick element. The conventional method to calculate residual stress is by using implicit scheme that because of the welding and cooling time is relatively high. In this work, the author shows that it could use the explicit scheme with the mass scaling technique, and time consuming during the analysis will be reduced very efficiently. By using this new technique, it will be possible to simulate relatively large three dimensional structures.

  18. Flow Accelerated Corrosion of Carbon Steel in the Feedwater System of PWR Plants - Behaviour of Welds and Weld Assemblies (United States)

    Mansour, C.; Pavageau, E. M.; Faucher, A.; Inada, F.; Yoneda, K.; Miller, C.; Bretelle, J.-L.

    Flow Accelerated Corrosion (FAC) of carbon steel is a phenomenon that has been studied for many years. However, to date, the specific behavior of welds and weld assemblies of carbon steel towards this phenomenon has been scarcely examined. An experimental program of FAC of welds and weld assemblies is being conducted by EDF and CRIEPI. This paper describes the results obtained on the behavior of weld metal independently of its behavior in a weld assembly as well as the sensitivity to FAC of various weld assembly configurations. Tests are performed, at EDF, in the CIROCO loop which permits to follow the FAC rate by gammametry measurements, and at CRIEPI, in the PRINTEMPS loop where FAC is measured by laser displacement sensor. Welds are performed by two different methods: Submerged Arc Welding (SAW) and Gas Tungsten Arc Welding (GTAW). The influence of several parameters on FAC of welds is examined: welding method, chromium content and temperature. For weld assemblies, only the impact of chromium content is studied. All the tests are conducted in ammonia medium at pH 9.0 and oxygen concentration lower then 1 ppb. Chemical parameters, as the pH, the conductivity and oxygen concentration, are measured in situ during the test and surface characterizations are performed after the test. The results show that, with more than 0.15% chromium, no FAC is detected on the weld metal, which is similar to the base metal behaviour. For the same and lower chromium content, the two types of metal have the same FAC rate. Concerning the temperature effect, for both metals FAC rate decreases with temperature increase above 150°C. Below 150 °C, their behaviour seems to be different. For weld assemblies, the study of different configurations shows that the chromium content is the main parameter affecting the behaviour of the specimens. Additional tests and modeling studies will be conducted in order to complete the results.

  19. Use of flux welding slag of the Mn-O-SiO{sub 2} system for the obtaining of a new alloyed agglomerated flux; Empleo de escorias de soldadura del sistema MnO-SiO{sub 2} para la obtencion de un nuevo fundente aglomerado aleado

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, A.; Quintana, R.; Garcia, L. L.; Perdomo, L.; Jimenez, G.; Gomez, C. R.; Alguacil, F. J.; Cores, A.


    This paper deals with the use of welding slags of the MnO-SiO{sub 2} system fluxes, coming from the recovering by means of the submerged arc welding in the manufacturing of agglomerated fluxes for surfacing with the same propose. the composition of the matrix is studied by means of an experimental design in a restricted area of the Mc Lean Anderson kind, the technological behaviour of the different mixtures is checked, and the results of the best types that have alloy charges included are analysed by a characterization of the weld. (Author) 20 refs.

  20. Effect of neutron irradiation on the mechanical properties of weld overlay cladding for reactor pressure vessel (United States)

    Tobita, Tohru; Udagawa, Makoto; Chimi, Yasuhiro; Nishiyama, Yutaka; Onizawa, Kunio


    This study investigates the effects of high fluence neutron irradiation on the mechanical properties of two types of cladding materials fabricated using the submerged-arc welding and electroslag welding methods. The tensile tests, Charpy impact tests, and fracture toughness tests were conducted before and after the neutron irradiation with a fluence of 1 × 1024 n/m2 at 290 °C. With neutron irradiation, we could observe an increase in the yield strength and ultimate strength, and a decrease in the total elongation. All cladding materials exhibited ductile-to-brittle transition behavior during the Charpy impact tests. A reduction in the Charpy upper-shelf energy and an increase in the ductile-to-brittle transition temperature was observed with neutron irradiation. There was no obvious decrease in the elastic-plastic fracture toughness (JIc) of the cladding materials upon irradiation with high neutron fluence. The tearing modulus was found to decrease with neutron irradiation; the submerged-arc-welded cladding materials exhibited low JIc values at high temperatures.

  1. Multiple exposure to metals in eight types of welding. (United States)

    Apostoli, P; Porru, S; Brunelli, E; Alessio, L


    This article evaluates multiple exposures to metals in different types of metal welding such as manual metal arc for mild and stainless steel, continuous wire, submerged arc, laser and brazing. Environmental monitoring was carried out in eight different occupational situations and the inductively coupled plasma mass spectrometry technique was adopted in order to characterize exposure to several elements simultaneously and with high accuracy. The results showed that up to 23 elements could be measured. The highest concentrations were found for Al, Mn, Fr, Ni, Cr, Cu and Zn. For some elements such as In, Nd, I, Rb the concentrations were very low. A qualitative and quantitative variation in fume composition was observed at a certain distance from the welding point, which should be to taken into account when evaluating indirect exposures. It would also be possible, with this technique, to identify specific elements in the mixture which could also be measured in biological fluids.

  2. Effect of molybdenum addition on microstructure and mechanical properties of plain carbon steel weld

    Directory of Open Access Journals (Sweden)

    Jyoti Menghani


    Full Text Available The present investigation has two main objectives; first is optimization of welding process parameters of submerged arc welding (SAW using Taguchi philosophy and second is to improve the mechanical properties such as strength and microhardness of weld joint by alloying with varying amounts of molybdenum. For optimization of welding process, parameters Taguchi philosophy have been applied on a mild steel plate (AISI C- 1020 of 10 mm thickness with 60o groove angle with arc voltage and welding speed as variables and bead width as output variables. A mathematical relationship between bead width, arc voltage and welding speed has also been found using multiple regression analysis for the present base metal plate geometry. After optimizing welding parameters, molybdenum has been added individually to the welding area in varying percentages. The properties of alloyed and unalloyed weld metal bead are compared. The mechanical characterization of weld has been done in terms of microhardness, tensile strength, whereas microstructural characterization has been performed using optical microscopy, XRD and EDS. The presence of molybdenum resulted in bainite structure in weld bead having a refined grain structure, enhancement in tensile strength and microhardness. The XRD results showed the formation of molybdenum carbides justifying the increase in microhardness value.

  3. Carbothermic reduction of pyrolusite for obtaining carbon bearing ferromanganese and slags, adequated to the development of welding materials; Reduccion carbotermica de pirolusita para la obtencion de ferromanganeso y escoria, adecuados al desarrollo de materiales de soldadura

    Energy Technology Data Exchange (ETDEWEB)

    Cruz-Crespo, A.; Garcia-Sanchez, L. L.; Quintana-Puchol, R.; Perdomo Gonzalez, L.; Gomez-Perez, C. R.; Jimenez-Vielsa, G. E.; Cores-Sanchez, A.


    The high carbon ferromanganese obtained by means of carbothermic reduction in an electric arc furnace of direct current is proposed. the ideal composition of slag oxides to achieve a flux to be used in the submerged arc welding (SAW) is established. Calculation for charge components (pyrolusite, coke, steel wool, lime, rutile and fluorite) for no fluxes technology for FeMn is carried out taking into account the welding fluxes characteristics of the SiO{sub 2}-MnO-CaO system. Change materials reduction experiments to obtain FeMn and slag are used to develop a SAW flux. (Author) 21 refs.

  4. The Microstructure and Pitting Resistance of Weld Joints of 2205 Duplex Stainless Steel (United States)

    Wu, Mingfang; Liu, Fei; Pu, Juan; Anderson, Neil E.; Li, Leijun; Liu, Dashuang


    2205 duplex stainless steel (DSS) was welded by submerged arc welding. The effects of both heat input and groove type on the ferrite/austenite ratio and elemental diffusion of weld joints were investigated. The relationships among welding joint preparation, ferrite/austenite ratio, elemental diffusion, and pitting corrosion resistance of weld joints were analyzed. When the Ni content of the weld wire deposit was at minimum 2-4% higher than that of 2205 DSS base metal, the desired ratio of ferrite/austenite and elemental partitioning between the austenite and ferrite phases were obtained. While the pitting sensitivity of weld metal was higher than that of base metal, the self-healing capability of the passive film of weld metal was better than that of the base metal when a single V-type groove was used. Furthermore, the heat input should be carefully controlled since pitting corrosion occurred readily in the coarse-grained heat-affected zone near the fusion line of welded joints.

  5. The use of neutron diffraction for the determination of the in-depth residual stresses profile in weld coatings; A utilizacao da difracao de neutroes na determinacao do perfil de tensoes residuais em revestimentos por soldadura

    Energy Technology Data Exchange (ETDEWEB)

    Marques, Maria Jose; Batista, A.C.; Nobre, J.P. [Universidade de Coimbra (Portugal). Dept. de Fisica. Centro de Estudos de Materiais por Difraccao de Raios X (CEMDRX); Loureiro, Altino [Universidade de Coimbra (Portugal). Dept. de Engenharia Mecanica. Centro de Engenharia Mecanica (CEMUC); Kornmeier, Joana R., E-mail: [Technische Universitaet Muenchen, Garching (Germany). FRM II


    The neutron diffraction is a non-destructive technique, particularly suitable for the analysis of residual stress fields in welds. The technique is used in this article to study ferritic samples, coated by submerged arc welding using stainless steel filler metals. This procedure is often used for manufacturing process equipment for chemical and nuclear industries, for ease of implementation and economic reasons. The main disadvantage of that processes is the cracking phenomenon that often occurs at the interface between the base material and coatings, which can be minimized by performing post-weld stress relief heat treatments. The samples analyzed in this study were made of carbon steel plates, coated by submerged arc welding two types of stainless steel filler metals. For the first layer was used one EN 12 072 - S 2 U 23 12 electrode, while for the second and third layers were used an EN 12 072 - 19 12 3 S L electrode. After cladding, the samples were submitted to a post-weld heat treatment for 1 hour at 620 deg C. The residual stress profiles obtained by neutron diffraction evidence the relaxation of residual stress given by the heat treatment. (author)


    Directory of Open Access Journals (Sweden)

    Janette Brezinová


    Full Text Available This contribution deals with the analysis of the renovation layer quality of continuous casting steel rolls, developed through the submerged arc surfacing method (SAW. The continuous casting roll was analysed via the degradation phenomena which act during the operation. Four kinds of filler materials were used for the renovation of the worn roll. Surfacing was carried out as a three-layer in order to eliminate the need for intermediate layer formation. The quality of weld deposits was evaluated in terms of the structure, hardness and wear resistance of weld deposits at 23°C and 400 °C using pin-on-disc wear test. The best properties showed newly developed filler material W8-WLDC8 from the point of view of the hardness, together with wear resistance of the deposited layers in room and elevated temperatures.

  7. Quality of weld clads applied by SAW method in adhesive wear conditions

    Directory of Open Access Journals (Sweden)

    Janette Brezinová


    Full Text Available This contribution deals with the analysis of the renovation layer quality of continuous casting steel rolls, developed through the submerged arc surfacing method (SAW. The continuous casting roll was analysed via the degradation phenomena which act during the operation. Four kinds of filler materials were used for the renovation of the worn roll. Surfacing was carried out as a three-layer in order to eliminate the need for intermediate layer formation. The quality of weld deposits was evaluated in terms of the structure, hardness and wear resistance of weld deposits at 23°C and 400 °C using pin-on-disc wear test. The best properties showed newly developed filler material W8-WLDC8 from the point of view of the hardness, together with wear resistance of the deposited layers in room and elevated temperatures.

  8. Investigation on Mechanical Properties of 9%Cr/CrMoV Dissimilar Steels Welded Joint (United States)

    Liu, Xia; Lu, Fenggui; Yang, Renjie; Wang, Peng; Xu, Xiaojin; Huo, Xin


    Advanced 9%Cr steel with good heat resistance and CrMoV with good toughness were chosen as candidate materials to fabricate combined rotor for steam turbine operating at over 620 °C. But the great difference in base metals properties presents a challenge in achieving sound defect-free joint with optimal properties in dissimilar welded rotor. In this paper, appropriate selection of filler metal, welding parameters, and post-weld heat treatment was combined to successfully weld 1100-mm-diameter 9%Cr/CrMoV dissimilar experimental rotor through ultra-narrow gap submerge arc welding. Some properties such as hardness, low-cycle fatigue (LCF), and high-cycle fatigue (HCF) combined with microstructural characterization qualify the integrity of the weld. Microstructural analysis indicated the presence of high-temperature tempered martensite as the phase responsible for the improved properties obtained in the weld. The Coffin-Manson parameters were obtained by fitting the data in LCF test, while the conditional fatigue strength was derived from the HCF test based on S-N curve. Analysis of hardness profile showed that the lowest value occurred at heat-affected zone adjacent to base metal which represents the appropriate location of fracture for the samples after LCF and HCF tests.

  9. Characterization of the Multi-Pass Weld Metal and the Effect of Post-Weld Heat Treatment on Its Microstructure and Toughness (United States)

    Wang, Xuelin; Shang, Chengjia; Wang, Xuemin

    In multi-pass welding process, various thermal cycle of both weld metal (WM) and heat affected zone (HAZ) will be subjected several times. This will make the initial microstructure occur an irreversible transformation. As the transformed microstructure become extremely complex, the mechanical properties, especially the low temperature toughness are very much fluctuant. In this research, the microstructure and low temperature toughness of WM obtained from a real multi-pass weld joint (up to 55 mm) by submerged arc welding have been elaborated. The results indicated that the necklace-type coarse martensite-austenite (M-A) constituent formed in interlayer heat affected zone (IHAZ) of WM and the impact energy of WM at -40 °C was only 39 J. Furthermore, by conventional tempering with holding time of 30 min, the toughness of WM can't be effectively improved. However, by a new developed heat treatment process, the toughness of WM could be significantly improved, and it is believed to be caused by the composition of weld metal and the post-welding heat treatment process. It also shows that the decomposition of M-A constituent and formation of the retained austenite are the mechanism of the improvement of low temperature toughness.

  10. Obtaining in an electric arc furnace alloys of the Fe-Mn-Cr-C system and slag destined to the development of welding consumables

    Directory of Open Access Journals (Sweden)

    Lorenzo Perdomo-González


    Full Text Available The production of chromium manganese ferroalloys for the use in the development of alloying loads of welding consumables is presented. On the basis of variations in the proportions of the chromium and manganese minerals in the loads, different combinations are established, which allow obtaining multicomponent ferroalloys with composition ranging from 9 to 32 % chromium and from 24 to 65 % manganese. The melting-reduction process is carried out in an electric arc furnace with a graphite crucible and with the presence of coke as a reducing component which guarantees the obtaining of high carbon alloys (5–6 %. The use of the multicomponent ferroalloy in the formulation of welding consumables simplifies and makes cheaper the obtaining of these materials. As result of metallurgical processing, slag formed by the silicon, aluminum, magnesium, manganese and calcium oxides are obtained, which are feasible to use in the production of flux matrices for submerged arc welding process.


    Directory of Open Access Journals (Sweden)

    Sukanto Jatmiko


    Full Text Available In this globalization era technological advances growed very fast. In shipping industry of development process shipbuilding of principal feedstock to used steel plate, with construction tacking on using welder method.In this research purpose of lifted is know number of requirement (consumable electrode for welder SAW at block-block ship DCV 18500 DWT in PT. Jasa Marina Indah Semarang.At this experiment specimen applied is low carbon steel of type ST 42 with thickness of 12, 13, 14, 17, 19 dan 24 mm. Research is done by the way of making specimen at every plate thickness. Then is done path measurement of length, used electrode length, and weight flux applied at the welder.From result of gauging and data calculation welder at block DB 5(p/c/s, SS5A(p/s, SS 5B(p/s, UD 5C, and TB 102 (p/c/s will be known number of electrodes applied in welder SAW and number of flux used.

  12. Simultaneous obtention of multicomponent ferroalloy and slag from black sands for the development of electrical arc welding consumables; Obtencion simultanea de ferroaleacion multicomponents y escoria a partir de areas negras, para el desarrollo de consumibles de doldadura por arco electrico

    Energy Technology Data Exchange (ETDEWEB)

    Cruz-Crespo, A.; Gomez-Rodriguez, L.; Garcia-Sanchez, L. L.; Quintana-Puchol, R.; Cerpa-Naranjo, A.; Cores-Sanchez, A.


    In this paper, chemical and mineralogical characterizations of the black sands of the Mejias placer of Sagua de Tanamo (the most important beach littoral placer of the northwest of oriental Cuba) are exposed. Starting from these characterizations a calculation strategy is developed for the making of the metallurgical load that allows to obtain simultaneously, when processed by carbothermic reduction in an electrical arc furnace, a multicomponent ferroalloy and a useful slag for the making of electric arch welding consumables. The powder of the obtained slag is agglomerated with liquid glass. The resulting pellets, due to their behavior on the submerged arc welding (SAW) present technological and metallurgical properties that correspond with the requirements of an agglomerated flux matrix. The chemical composition of the multicomponent ferroalloy is constituted by metallic elements of high metallurgical and alloyed values (V, Cr, Mo, Ti, Nb). It is appropriate for the formulation of consumables for manual welding (SMAW) and SAW, as well. (Author) 15 refs.

  13. Welding of stainless and nickel based materials in the chemical industry. Consumables and procedures. Soldadura de aceros inoxidables y de materiales de base niquel en la industria quimica. Consumibles y procedimientos

    Energy Technology Data Exchange (ETDEWEB)

    Stromberg, J.; Budgifvars, S. (The ESA Grouo, Geoteborg (Sweden))


    In the chemical and petrochemical process industry a large range of various stainless and nickel based materials are used to meet high demands on corrosion resistance for optimum service performance. These materials include standard stainless steels, duplex and super duplex steels, super austenitic steels and nickel based alloys. Many components are being welded in the construction stage or may later on have to be repaired by welding. The design of components also often calls for joining or cladding of dissimilar materials to optimize the use of the material properties and for economical reasons to reduce the amount of expensive materials. Consumables and procedures have been developed to give weld metals to match the corrosion and strength requirements of the materials. There is a wide selection of MM electrodes with different coatings available and new types of stainless flux cored wires are being introduced. Especially for cladding of large surfaces the submerged arc strip cladding process offer high productivity solutions. (Author) 6 ref.

  14. Defect detection of partially complete SAW and TIG welds using the ultrasonic time-of-flight diffraction method (United States)

    Lawson, Shaun W.; Bonser, Gary R.


    An application of machine vision applied to the analysis of ultrasonic images formed using the time-of-flight diffraction (TOFD) method on incomplete weld geometries is described. The rationale of the work being to identify weld defects as soon as they are produced, thereby reducing the costs of any subsequent repairs. The analysis uses TOFD scans as input to a filtering and 'window' based variance operator for the segmentation of suspect defect areas inside the weld region. A suite of pc based software and a high temperature TOFD data acquisition system have been benchmarked through a series of demonstration trials on both 80mm thick carbon steel submerged arc welded testpieces, and 25mm thick carbon steel tungsten inert gas welded testpieces. The range of intentionally implanted defects, from root cracks to lack of side wall fusion, were detected with an overall accuracy of 79 percent on a data set of 174 defects on scans performed at 10-90 percent weld completion.

  15. High Temperature Corrosion and Characterization Studies in Flux Cored Arc Welded 2.25Cr-1Mo Power Plant Steel (United States)

    Kumaresh Babu, S. P.; Natarajan, S.


    Higher productivity is registered with Flux cored arc welding (FCAW) process in many applications. Further, it combines the characteristics of shielded metal arc welding (SMAW), gas metal arc welding (GMAW), and submerged arc welding (SAW) processes. This article describes the experimental work carried out to evaluate and compare corrosion and its inhibition in SA 387 Gr.22 (2.25Cr-1Mo) steel weldments prepared by FCAW process with four different heat inputs exposed to hydrochloric acid medium at 0.1, 0.5, and 1.0 M concentrations. The parent metal, weld metal, and heat-affected zone are chosen as regions of exposure for the study carried out at 100 °C. Electrochemical polarization techniques such as Tafel line extrapolation (Tafel) and linear polarization resistance (LPR) have been used to measure the corrosion current. The role of hexamine and mixed inhibitor (thiourea + hexamine in 0.5 M HCl), each at 100 ppm concentration is studied in these experiments. Microstructural observation, hardness survey, surface characterization, and morphology using scanning electron microscope (SEM) and x-ray diffraction (XRD) have been made on samples to highlight the nature and extent of film formation. The film is found to contain Fe2Si, FeSi2, FeMn3, Fe7Mo3, Fe3O4, FeO, FeCr, AlO7Fe3SiO3, and KFe4Mn77Si19.

  16. Methodology for Estimating Thermal and Neutron Embrittlement of Austenitic Stainless Steel Welds During Service in Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Chopra, O. K.; Rao, A. S.


    The effect of thermal aging on the degradation of fracture toughness and Charpy-impact properties of austenitic stainless steel (SS) welds has been characterized at reactor temperatures. The solidification behavior and the distribution and morphology of the ferrite phase in SS welds are described. Thermal aging of the welds results in moderate decreases in Charpy-impact strength and fracture toughness. The upper-shelf Charpy-impact energy of aged welds decreases by 50–80 J/cm2. The decrease in fracture toughness J-R curve, or JIc is relatively small. Thermal aging has minimal effect on the tensile strength. The fracture properties of SS welds are insensitive to filler metal; the welding process has a significant effect. The large variability in the data makes it difficult to establish the effect of the welding process on fracture properties of SS welds. Consequently, the approach used for evaluating thermal and neutron embrittlement of austenitic SS welds relies on establishing a lower-bound fracture toughness J-R curve for unaged and aged, and non-irradiated and irradiated, SS welds. The existing fracture toughness J-R curve data for SS welds have been reviewed and evaluated to define lower-bound J-R curve for submerged arc (SA)/shielded metal arc (SMA)/manual metal arc (MMA) welds and gas tungsten arc (GTA)/tungsten inert gas (TIG) welds in the unaged and aged conditions. At reactor temperatures, the fracture toughness of GTA/TIG welds is a factor of about 2.3 higher than that of SA/SMA/MMA welds. Thermal aging decreases the fracture toughness by about 20%. The potential combined effects of thermal and neutron embrittlement of austenitic SS welds are also described. Lower-bound curves are presented that define the change in coefficient C and exponent n of the power-law J-R curve and the JIc value for SS welds as a function of neutron dose. The potential effects of reactor coolant environment on the fracture toughness of austenitic SS welds are also discussed.

  17. Hot cracking of welded joints of the 7CrMoVTiB 10-10 (T/P24) steel (United States)

    Adamiec, J.


    Bainitic steel 7CrMoVTiB10-10 is one the newest steels for waterwalls of modern industrial boilers [1]. In Europe, attempts have been made to make butt welded joints of pipes made of this steel of the diameter up to 51 mm and thickness up to 8 mm. Many cracks have been observed in the welded joint, both during welding and transport and storage [2-4]. The reasons of cracking and the prevention methods have not been investigated. No comprehensive research is carried out in Europe in order to automate the welding process of the industrial boiler elements made of modern bainitic steel, such as 7CrMoVTiB10-10. There is no information about its overall, operative and local weldability, influence of heat treatment, as well as about resistance of the joints to cracking during welding and use. The paper presents experience of Energoinstal SA from development of technology and production of waterwalls of boilers made of the 7CrMoVTiB 10-10 steel on a multi-head automatic welder for submerged arc welding.

  18. Detrimental Cr-rich Phases Precipitation on SAF 2205 Duplex Stainless Steels Welds After Heat Treatment

    Directory of Open Access Journals (Sweden)

    Argelia Fabiola Miranda Pérez

    Full Text Available Abstract The austeno-ferritic Stainless Steels are commonly employed in various applications requiring structural performances with enhanced corrosion resistance. Their characteristics can be worsened if the material is exposed to thermal cycles, since the high-temperature decomposition of ferrite causes the formation of detrimental secondary phases. The Submerged Arc Welding (SAW process is currently adopted for joining DSS owing to its relatively simple execution, cost savings, and using molten slag and granular flux from protecting the seam of atmospheric gases. However, since it produces high contents of δ-ferrite in the heat affected zone and low content of γ-austenite in the weld, high-Ni filler materials must be employed, to avoid excessive ferritization of the joint. The present work is aimed to study the effect of 3 and 6 hours isothermal heat treatments at 850°C and 900°C in a SAF 2205 DSS welded joint in terms of phases precipitation. The results showed the presence of σ-phase at any time-temperature combination, precipitating at the δ/γ interphases and often accompanied by the presence of χ-phase. However, certain differences in secondary phases amounts were revealed among the different zones constituting the joint, ascribable both to peculiar elements partitioning and to the different morphology pertaining to each microstructure.

  19. Material property evaluations of bimetallic welds, stainless steel saw fusion lines, and materials affected by dynamic strain aging

    Energy Technology Data Exchange (ETDEWEB)

    Rudland, D.; Scott, P.; Marschall, C.; Wilkowski, G. [Battelle Memorial Institute, Columbus, OH (United States)


    Pipe fracture analyses can often reasonably predict the behavior of flawed piping. However, there are material applications with uncertainties in fracture behavior. This paper summarizes work on three such cases. First, the fracture behavior of bimetallic welds are discussed. The purpose of the study was to determine if current fracture analyses can predict the response of pipe with flaws in bimetallic welds. The weld joined sections of A516 Grade 70 carbon steel to F316 stainless steel. The crack was along the carbon steel base metal to Inconel 182 weld metal fusion line. Material properties from tensile and C(T) specimens were used to predict large pipe response. The major conclusion from the work is that fracture behavior of the weld could be evaluated with reasonable accuracy using properties of the carbon steel pipe and conventional J-estimation analyses. However, results may not be generally true for all bimetallic welds. Second, the toughness of austenitic steel submerged-arc weld (SAW) fusion lines is discussed. During large-scale pipe tests with flaws in the center of the SAW, the crack tended to grow into the fusion line. The fracture toughness of the base metal, the SAW, and the fusion line were determined and compared. The major conclusion reached is that although the fusion line had a higher initiation toughness than the weld metal, the fusion-line J-R curve reached a steady-state value while the SAW J-R curve increased. Last, carbon steel fracture experiments containing circumferential flaws with periods of unstable crack jumps during steady ductile tearing are discussed. These instabilities are believed to be due to dynamic strain aging (DSA). The paper discusses DSA, a screening criteria developed to predict DSA, and the ability of the current J-based methodologies to assess the effect of these crack instabilities. The effect of loading rate on the strength and toughness of several different carbon steel pipes at LWR temperatures is also discussed.

  20. Welding Curriculum. (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.…



    Marcos Theodoro Muller; Rafael Rodolfo de Melo; Diego Martins Stangerlin


    The term "wood welding" designates what can be defined as "welding of wood surfaces". This new process, that it provides the joint of wood pieces without the use of adhesives or any other additional material, provokes growing interest in the academic environment, although it is still in laboratorial state. Linear friction welding induced bymechanical vibration yields welded joints of flat wood surfaces. The phenomenon of the welding occurs in less time than 10 seconds, with the temperature in...

  2. Advanced Welding Concepts (United States)

    Ding, Robert J.


    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.

  3. Resistance welding

    DEFF Research Database (Denmark)

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


    Resistance welding comprises not only the well known spot welding process but also more complex projection welding operations, where excessive plastic deformation of the weld point may occur. This enables the production of complex geometries and material combinations, which are often not possible...... to weld by traditional spot welding operations. Such joining processes are, however, not simple to develop due to the large number of parameters involved. Development has traditionally been carried out by large experimental investigations, but the development of a numerical programme system has changed...

  4. Welding Technician (United States)

    Smith, Ken


    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…

  5. Quality control on crimping of large diameter welding pipe (United States)

    Fan, Lifeng; Gao, Ying; Li, Qiang; Xu, Hongshen


    Crimping is used in production of large diameter submerged-arc welding pipes. Many researches are focused on crimping in certain manufacturing mode of welding pipe. The application scopes of research achievements become limited due to lack of uniformity in theoretical analysis. In order to propose a crimping prediction method in order to control forming quality, the theory model of crimping based on elastic-plastic mechanics is established. The main technical parameters are determined by theoretical analysis, including length of crimping, base radius of punch, terminal angle of punch, base radius of die, terminal angle of die and horizontal distance between punch and die. In addition, a method used to evaluate the forming quality is presented, which investigates the bending angle after springback, forming force, straight edge length and equivalent radius of curvature. In order to investigate the effects of technical parameters on forming quality, a two-dimensional finite element model is established by finite element software ABAQUS. The finite element model is verified in that its shapes error is less than 5% by comparable experiments, which shows that their geometric precision meets demand. The crimping characteristics is obtained, such as the distribution of stress and strain and the changes of forming force, and the relation curves of technical parameters on forming quality are given by simulation analysis. The sensitivity analysis indicates that the effects of length of crimping, technical parameters of punch on forming quality are significant. In particular, the data from simulation analysis are regressed by response surface method (RSM) to establish prediction model. The feasible technical parameters are obtained from the prediction model. This method presented provides a new thought used to design technical parameters of crimping forming and makes a basis for improving crimping forming quality.

  6. Soldadura (Welding). Spanish Translations for Welding. (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…

  7. WELDING TORCH (United States)

    Correy, T.B.


    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)

  8. The Application of Stress-Relaxation Test to Life Assessment of T911/T22 Weld Metal (United States)

    Cao, Tieshan; Zhao, Jie; Cheng, Congqian; Li, Huifang


    A dissimilar weld metal was obtained through submerged arc welding of a T911 steel to a T22 steel, and its creep property was explored by stress-relaxation test assisted by some conventional creep tests. The creep rate information of the stress-relaxation test was compared to the minimum and the average creep rates of the conventional creep test. Log-log graph showed that the creep rate of the stress-relaxation test was in a linear relationship with the minimum creep rate of the conventional creep test. Thus, the creep rate of stress-relaxation test could be used in the Monkman-Grant relation to calculate the rupture life. The creep rate of the stress-relaxation test was similar to the average creep rate, and thereby the rupture life could be evaluated by a method of "time to rupture strain." The results also showed that rupture life which was assessed by the Monkman-Grant relation was more accurate than that obtained through the method of "time to rupture strain."

  9. Plasma arc welding weld imaging (United States)

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


    A welding torch for plasma arc welding apparatus has a transparent shield cup disposed about the constricting nozzle, the cup including a small outwardly extending polished lip. A guide tube extends externally of the torch and has a free end adjacent to the lip. First and second optical fiber bundle assemblies are supported within the guide tube. Light from a strobe light is transmitted along one of the assemblies to the free end and through the lip onto the weld site. A lens is positioned in the guide tube adjacent to the second assembly and focuses images of the weld site onto the end of the fiber bundle of the second assembly and these images are transmitted along the second assembly to a video camera so that the weld site may be viewed continuously for monitoring the welding process.

  10. Hardness analysis of welded joints of austenitic and duplex stainless steels (United States)

    Topolska, S.


    Stainless steels are widely used in the modern world. The continuous increase in the use of stainless steels is caused by getting greater requirements relating the corrosion resistance of all types of devices. The main property of these steels is the ability to overlap a passive layer of an oxide on their surface. This layer causes that they become resistant to oxidation. One of types of corrosion-resistant steels is ferritic-austenitic steel of the duplex type, which has good strength properties. It is easily formable and weldable as well as resistant to erosion and abrasive wear. It has a low susceptibility to stress-corrosion cracking, to stress corrosion, to intercrystalline one, to pitting one and to crevice one. For these reasons they are used, among others, in the construction of devices and facilities designed for chemicals transportation and for petroleum and natural gas extraction. The paper presents the results which shows that the particular specimens of the ][joint representing both heat affected zones (from the side of the 2205 steel and the 316L one) and the weld are characterized by higher hardness values than in the case of the same specimens for the 2Y joint. Probably this is caused by machining of edges of the sections of metal sheets before the welding process, which came to better mixing of native materials and the filler metal. After submerged arc welding the 2205 steel still retains the diphase, austenitic-ferritic structure and the 316L steel retains the austenitic structure with sparse bands of ferrite σ.

  11. WELDING METHOD (United States)

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


    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.

  12. Statistical analyses of fracture toughness results for two irradiated high-copper welds

    Energy Technology Data Exchange (ETDEWEB)

    Nanstad, R.K.; McCabe, D.E.; Haggag, F.M.; Bowman, K.O.; Downing, D.J.


    The objectives of the Heavy-Section Steel Irradiation Program Fifth Irradiation Series were to determine the effects of neutron irradiation on the transition temperature shift and the shape of the K{sub Ic} curve described in Sect. 6 of the ASME Boiler and Pressure Vessel Code. Two submerged-arc welds with copper contents of 0.23 and 0.31% were commercially fabricated in 215-mm-thick plates. Charpy V-notch (CVN) impact, tensile, drop-weight, and compact specimens up to 203.2 mm thick (1T, 2T, 4T, 6T, and 8T C(T)) were tested to provide a large data base for unirradiated material. Similar specimens with compacts up to 4T were irradiated at about 288{degrees}C to a mean fluence of about 1.5 {times} 10{sup 19} neutrons/cm{sup 2} (>1 MeV) in the Oak Ridge Research Reactor. Both linear-elastic and elastic-plastic fracture mechanics methods were used to analyze all cleavage fracture results and local cleavage instabilities (pop-ins). Evaluation of the results showed that the cleavage fracture toughness values determined at initial pop-ins fall within the same scatter band as the values from failed specimens; thus, they were included in the data base for analysis (all data are designated K{sub Jc}).

  13. Syllabus in Trade Welding. (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…

  14. Pragmatic analysis of the electric submerged arc furnace continuum (United States)

    Karalis, K.; Karkalos, N.; Antipas, G. S. E.; Xenidis, A.


    A transient mathematical model was developed for the description of fluid flow, heat transfer and electromagnetic phenomena involved in the production of ferronickel in electric arc furnaces. The key operating variables considered were the thermal and electrical conductivity of the slag and the shape, immersion depth and applied electric potential of the electrodes. It was established that the principal stimuli of the velocities in the slag bath were the electric potential and immersion depth of the electrodes and the thermal and electrical conductivities of the slag. Additionally, it was determined that, under the set of operating conditions examined, the maximum slag temperature ranged between 1756 and 1825 K, which is in accordance with industrial measurements. Moreover, it was affirmed that contributions to slag stirring due to Lorentz forces and momentum forces due to the release of carbon monoxide bubbles from the electrode surface were negligible.

  15. Similarity of Ferrosilicon Submerged Arc Furnaces With Different Geometrical Parameters

    Directory of Open Access Journals (Sweden)

    Machulec B.


    Full Text Available In order to determine reasons of unsatisfactory production output regarding one of the 12 MVA furnaces, a comparative analysis with a furnace of higher power that showed a markedly better production output was performed. For comparison of ferrosilicon furnaces with different geometrical parameters and transformer powers, the theory of physical similarity was applied. Geometrical, electrical and thermal parameters of the reaction zones are included in the comparative analysis. For furnaces with different geometrical parameters, it is important to ensure the same temperature conditions of the reaction zones. Due to diverse mechanisms of heat generation, different criteria for determination of thermal and electrical similarity for the upper and lower reaction zones were assumed contrary to other publications. The parameter c3 (Westly was assumed the similarity criterion for the upper furnace zones where heat is generated as a result of resistive heating while the parameter J1 (Jaccard was assumed the similarity criterion for the lower furnace zones where heat is generated due to arc radiation.

  16. The National Shipbuilding Research Program. Emission Factors for Flux Core Rod Used in Gas Shielded Processes

    National Research Council Canada - National Science Library


    ...), shielded metal arc welding (SMAW), and submerged arc welding (SAW). There are presently some emission factors for welding operations that have been developed by the United States Environmental Protection Agency (USEPA...

  17. 49 CFR 195.106 - Internal design pressure. (United States)


    ... and is subsequently heated, other than by welding or stress relieving as a part of welding, to a... Seamless 1.00 ASTM A 333/A 333M Seamless 1.00 Welded 1.00 ASTM A381 Double submerged arc welded 1.00 ASTM... 1.00 API 5L Seamless 1.00 Electric resistance welded 1.00 Electric flash welded 1.00 Submerged arc...

  18. Sunil Pandey

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. Sunil Pandey. Articles written in Sadhana. Volume 38 Issue 6 December 2013 pp 1369-1391. Effect of heat input on dilution and heat affected zone in submerged arc welding process · Hari Om Sunil Pandey · More Details Abstract Fulltext PDF. Submerged arc welding (SAW) is a fusion joining ...

  19. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. Hari Om. Articles written in Sadhana. Volume 38 Issue 6 December 2013 pp 1369-1391. Effect of heat input on dilution and heat affected zone in submerged arc welding process · Hari Om Sunil Pandey · More Details Abstract Fulltext PDF. Submerged arc welding (SAW) is a fusion joining process ...

  20. Distortion Control during Welding


    Akbari Pazooki, A.M.


    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...

  1. WELDING PROCESS (United States)

    Zambrow, J.; Hausner, H.


    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.

  2. Friction Stir Welding (United States)

    Nunes, Arthur C., Jr.


    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.

  3. An Investigation of the CSC-MIG Welding Process for Deposition of Conventional, Ultrafine and Nanostructured MMC Coatings (United States)

    Vespa, Patrick

    heat input weldment. The hardness of the deposited coatings decreased from 587 HV10 to 410 HV 10 when the energy input was increased from 10.1 J/mm to 108.7 J/mm. Using a pre-placed powder method, as in submerged arc welding, several coatings were embedded with either conventional, ultrafine or nanostructured WC powder. In the analysis of these tests, it was found that the method of embedding the WC particles into the coating had an effect on the overall dissolution of the reinforcing phase. Although the loss of the nanostructure was observed in coatings embedded with the nanostructured WC feedstock, the precipitation of ultrafine WC single crystals is likely to increase the wear resistance compared with conventional sized WC additions. This thesis contains the first journal articles submitted for publication using results from experiments conducted with a CSC-MIG welding system.

  4. Introduction to Welding. (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.


    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. Advanced Welding Applications (United States)

    Ding, Robert J.


    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.

  7. Reprocessing weld and method

    Energy Technology Data Exchange (ETDEWEB)

    Killian, M.L.; Lewis, H.E.


    A process is described for improving the fatigue resistance of a small primary structural weld at a joint between structural members of a weldment, the weld having been made with the welding energy input of E[sub 1], the process comprising: applying a reprocessing weld on at least a portion of either one or both toes of the primary structural weld, thereby covering said toe portion, the reprocessing weld containing a filler metal and having a cross-sectional area which is less than the corresponding cross-sectional area of the primary structural weld, the reprocessing weld extending onto the face of the primary structural weld at one side of the toe portion covered and onto the structural member at the other side of the toe portion covered, and the total welding energy input, E[sub 2], used in said reprocessing the primary structural weld being less than the welding energy input E[sub 1] of the primary structural weld.

  8. 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...

  9. Welding Course Curriculum. (United States)

    Genits, Joseph C.

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

  10. Instructional Guidelines. Welding. (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…

  11. Physics of arc welding (United States)

    Eagar, T. W.


    A discussion of the factors controlling the size and shape of the weld fusion zone is presented along with a description of current theories of heat and fluid flow phenomena in the plasma and the molten metal weld pool. Although experimental results confirm that surface tension, plasma jets, and weld pool convection all strongly influence the fusion zone shape; no comprehensive model is available from which to predict welding behavior. It is proposed that the lack of such an understanding is a major impediment to development of automated welding processes. In addition, sensors for weld torch positioning are reviewed in terms of the mechnical and electromagnetic energy spectra which have been used. New developments in this area are also needed in order to advance the technology of automated welding.

  12. Dual wire weld feed proportioner (United States)

    Nugent, R. E.


    Dual feed mechanism enables proportioning of two different weld feed wires during automated TIG welding to produce a weld alloy deposit of the desired composition. The wires are fed into the weld simultaneously. The relative feed rates of the wires and the wire diameters determine the weld deposit composition.

  13. Component, Context and Manufacturing Model Library (C2M2L) (United States)


    Welding Shielded-Metal Arc Welding (Stick), GMAW ( TIG ), GMAW (MIG), Flux-Cored Arc Welding , Submerged Arc Welding Forming Press Forming Roll...manufacturing models for Welding , Casting, Forging, Ausforming, Coatings (organic and inorganic), Sheet and Plate Metal Cutting, Material Handling...23 4.1 WELDING

  14. Welding arc plasma physics (United States)

    Cain, Bruce L.


    The problems of weld quality control and weld process dependability continue to be relevant issues in modern metal welding technology. These become especially important for NASA missions which may require the assembly or repair of larger orbiting platforms using automatic welding techniques. To extend present welding technologies for such applications, NASA/MSFC's Materials and Processes Lab is developing physical models of the arc welding process with the goal of providing both a basis for improved design of weld control systems, and a better understanding of how arc welding variables influence final weld properties. The physics of the plasma arc discharge is reasonably well established in terms of transport processes occurring in the arc column itself, although recourse to sophisticated numerical treatments is normally required to obtain quantitative results. Unfortunately the rigor of these numerical computations often obscures the physics of the underlying model due to its inherent complexity. In contrast, this work has focused on a relatively simple physical model of the arc discharge to describe the gross features observed in welding arcs. Emphasis was placed of deriving analytic expressions for the voltage along the arc axis as a function of known or measurable arc parameters. The model retains the essential physics for a straight polarity, diffusion dominated free burning arc in argon, with major simplifications of collisionless sheaths and simple energy balances at the electrodes.

  15. Welding skate with computerized controls (United States)

    Wall, W. A., Jr.


    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. Computerized adaptive control weld skate with CCTV weld guidance project (United States)

    Wall, W. A.


    This report summarizes progress of the automatic computerized weld skate development portion of the Computerized Weld Skate with Closed Circuit Television (CCTV) Arc Guidance Project. The main goal of the project is to develop an automatic welding skate demonstration model equipped with CCTV weld guidance. The three main goals of the overall project are to: (1) develop a demonstration model computerized weld skate system, (2) develop a demonstration model automatic CCTV guidance system, and (3) integrate the two systems into a demonstration model of computerized weld skate with CCTV weld guidance for welding contoured parts.

  17. Modern Methods of Rail Welding (United States)

    Kozyrev, Nikolay A.; Kozyreva, Olga A.; Usoltsev, Aleksander A.; Kryukov, Roman E.; Shevchenko, Roman A.


    Existing methods of rail welding, which are enable to get continuous welded rail track, are observed in this article. Analysis of existing welding methods allows considering an issue of continuous rail track in detail. Metallurgical and welding technologies of rail welding and also process technologies reducing aftereffects of temperature exposure are important factors determining the quality and reliability of the continuous rail track. Analysis of the existing methods of rail welding enable to find the research line for solving this problem.

  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. Ultrasonic Stir Welding (United States)

    Nabors, Sammy


    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.

  20. Dual wire welding torch and method (United States)

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


    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. Studies of welded joints

    Directory of Open Access Journals (Sweden)

    J. M. Krupa


    Full Text Available Studies of a welded joint were described. The joint was made as a result of the reconstruction of a truss and one of the possible means to make a repair. The studies were of a simulation character and were targeted at the detection of welding defects and imperfections thatshould be eliminated in a real structure. A model was designed and on this model the tests and examinations were carried out. The modelwas made under the same conditions as the conditions adopted for repair. It corresponded to the real object in shape and dimensions, and in the proposed technique of welding and welding parameters. The model was composed of five plates joined together with twelve beads.The destructive and non-destructive tests were carried out; the whole structure and the respective welds were also examined visually. Thedefects and imperfections in welds were detected by surface methods of inspection, penetration tests and magnetic particle flaw detection.The model of the welded joint was prepared by destructive methods, a technique that would never be permitted in the case of a realstructure. For the investigations it was necessary to cut out the specimens from the welded joint in direction transverse to the weld run. The specimens were subjected to metallographic examinations and hardness measurements. Additionally, the joint cross-section was examined by destructive testing methods to enable precise determination of the internal defects and imperfections. The surface methods were applied again, this time to determine the severity of welding defects. The analysis has proved that, fabricated under proper conditions and with parameters of the welding process duly observed, the welded joint has good properties and repairs of this type are possible in practice.

  2. Robot welding process control (United States)

    Romine, Peter L.


    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. Explosive Welding of Pipes (United States)

    Drennov, Oleg; Drennov, Andrey; Burtseva, Olga


    For connection by welding it is suggested to use the explosive welding method. This method is rather new. Nevertheless, it has become commonly used among the technological developments. This method can be advantageous (saving material and physical resources) comparing to its statical analogs (electron-beam welding, argon-arc welding, plasma welding, gas welding, etc.), in particular, in hard-to-reach areas due to their geographic and climatic conditions. Explosive welding of cylindrical surfaces is performed by launching of welded layer along longitudinal axis of construction. During this procedure, it is required to provide reliable resistance against radial convergent strains. The traditional method is application of fillers of pipe cavity, which are dense cylindrical objects having special designs. However, when connecting pipes consecutively in pipelines by explosive welding, removal of the fillers becomes difficult and sometimes impossible. The suggestion is to use water as filler. The principle of non-compressibility of liquid under quasi-dynamic loading is used. In one-dimensional gasdynamic and elastic-plastic calculations we determined non-deformed mass of water (perturbations, which are moving in the axial direction with sound velocity, should not reach the layer end boundaries for 5-7 circulations of shock waves in the radial direction). Linear dimension of the water layer from the zone of pipe coupling along axis in each direction is >= 2R, where R is the internal radius of pipe.

  4. Aplicación de escoria granulada con aire a la soldadura automática//Application of slag granulated with air in the automatic welding

    Directory of Open Access Journals (Sweden)

    Daniel Pérez‐Pérez


    Full Text Available El objetivo del presente trabajo es evaluar las propiedades fundamentales de una escoria granulada con aire y su aplicación durante la soldadura automática con arco sumergido, comparándola con un fundente fundido granulado en agua. Para ello, se considera la influencia del procedimiento de fabricación de la escoria granulada con aire sobre sus propiedades físicas y la relación que tiene con su desempeño durante la soldadura y las propiedades mecánicas de las uniones obtenidas. Sedemuestra que las características de los tipos de granos evaluados (de escoria y de fundente son diferentes; sin embargo, esto no conduce a variaciones entre sus comportamientos operativos durante la soldadura, ni sobre las propiedades mecánicas de las uniones obtenidas; aunque se hace notar que el proceso de granulación de escorias con aire es más económico que el de granulacióncon agua.Palabras claves: escoria granulada, granulación seca, granulación húmeda, consumible de soldadura._______________________________________________________________________________AbstractThe objective of the present work is to evaluate the fundamentals properties of an air granulated slag and his use during the automatic submerged arc welding process, confront it to a water granulated fused flux. For it the manufacturing procedure influence of air granulated slag on its physical properties and this relation with its performance during the solder and mechanical properties ofwelding join obtained is considered. Is demonstrated that the characteristics of the types of evaluated grains (slag and fused flux are different; however, this does not conduce to variations among its operating behaviors during the welding process, neither on the welding joint mechanical properties obtained; but makes to be noticeable than the granulating process of slag with air is more economic than the of granulation with water.Key words: granulating slag, dry granulation, humid granulation, welding

  5. Measuring weld heat to evaluate weld integrity

    Energy Technology Data Exchange (ETDEWEB)

    Schauder, V., E-mail: [HKS-Prozesstechnik GmbH, Halle (Germany)


    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

  6. Fine welding with lasers. (United States)

    MacLellan, D


    The need for micro joining metallic alloys for surgical instruments, implants and advanced medical devices is driving a rapid increase in the implementation of laser welding technology in research, development and volume production. This article discusses the advantages of this welding method and the types of lasers used in the process.

  7. Laser Welding in Space (United States)

    Workman, Gary L.; Kaukler, William F.


    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.

  8. DC arc weld starter (United States)

    Campiotti, Richard H.; Hopwood, James E.


    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.

  9. 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.


    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

  10. Thermoplastic welding apparatus and method (United States)

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


    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.

  11. Laser forming and welding processes

    CERN Document Server

    Yilbas, Bekir Sami; Shuja, Shahzada Zaman


    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.

  12. Welding processes handbook

    CERN Document Server

    Weman, Klas


    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...

  13. A utilização da difração de neutrões na determinação do perfil de tensões residuais em revestimentos por soldadura The use of neutron diffraction for the determination of the in-depth residual stresses profile in weld coatings

    Directory of Open Access Journals (Sweden)

    Maria José Marques


    Full Text Available A técnica de difração de neutrões é usada neste artigo para estudar amostras ferríticas, revestidas comaços inoxidáveisausteníticos através de soldadura por arco submerso. Este procedimento é frequentemente usado no fabrico de equipamentos de processo para as indústrias química e nuclear, por facilidade de execução e razões económicas. A principal desvantagem deste processo de revestimento é a fissuração que frequentemente ocorre na interface material base/soldadura, potenciada pela presença de tensões residuais resultantes da operação de soldadura, a qual pode ser minimizada com a realização de tratamentos térmicos de relaxação de tensões. As amostras foram produzidas a partir de placas em aço ao carbono, tendo uma das superfícies sido revestida com dois tipos de aço inoxidável. Para a primeira camada foi usado um elétrodo EN 12072 - S 23 12 2 L e para a segunda e a terceira camadas foi usado um elétrodo EN 12072 - S 19 12 3 L. Após a soldadura, as amostras foram submetidas a um tratamento térmico de relaxação de tensões, durante 1 hora, à temperatura de 620ºC. Os perfis de tensões residuais obtidos por difração de neutrões evidenciam a relaxação de tensões residuais após o tratamento térmico realizado. A técnica de difração de neutrões revelou-se muito adequada na avaliação de tensões residuais neste tipo de ligações.The neutron diffraction is a non-destructive technique, particularly suitable for the analysis of residual stress fields in welds. The technique is used in this article to study ferritic samples, coated by submerged arc welding using stainless steel filler metals. This procedure is often used for manufacturing process equipment for chemical and nuclear industries, for ease of implementation and economic reasons. The main disadvantage of that processes is the cracking phenomenon that often occurs at the interface between the base material and coatings, which can be

  14. Thermal stir welding process (United States)

    Ding, R. Jeffrey (Inventor)


    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.

  15. Thermal stir welding apparatus (United States)

    Ding, R. Jeffrey (Inventor)


    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.

  16. Solar array welding developement (United States)

    Elms, R. V., Jr.


    The present work describes parallel gap welding as used for joining solar cells to the cell interconnect system. Sample preparation, weldable cell parameter evaluation, bond scheduling, bond strength evaluation, and bonding and thermal shock tests are described. A range of weld schedule parameters - voltage, time, and force - can be identified for various cell/interconnect designs that will provide adequate bond strengths and acceptably small electrical degradation. Automation of solar array welding operations to a significant degree has been achieved in Europe and will be receiving increased attention in the U.S. to reduce solar array fabrication costs.

  17. Review of Welding Terminology

    Directory of Open Access Journals (Sweden)

    Angelika Petrėtienė


    Full Text Available The paper discusses welding terms in accordance with the Lithuanian standard LST EN 1792 „Welding. The multilingual list of welding terms and similar processes”, „The Russian–Lithuanian dictionary of the terms of mechanical engineering technology and welding“ and the examples from postgraduates‘ final works. It analyses the infringement of lexical, word-building and morphological rules. First-year students should already be familiar with the standardized terms of their speciality. More active propagation of the terms should help to avoid terminology mistakes in various scientific spheres.

  18. Hybrid laser-arc welding

    DEFF Research Database (Denmark)

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

  19. 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...... been possible to control the welding width in incremental steps by adding more beams in a row. The laser power was used to independently control the keyhole and consequently the depth of fusion. An example of inline repair of a laser weld in butt joint configuration was examined. Zinc powder was placed...

  20. Friction stir welding tool (United States)

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


    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.

  1. Concurrent ultrasonic weld evaluation system (United States)

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


    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. Weld formation control at electron beam welding with beam oscillations


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


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

  3. Alternate Welding Processes for In-Service Welding (United States)


    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...

  4. Certification of a weld produced by friction stir welding (United States)

    Obaditch, Chris; Grant, Glenn J


    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.

  5. Welding defects at friction stir welding

    Directory of Open Access Journals (Sweden)

    P. Podržaj


    Full Text Available The paper presents an overview of different types of defects at friction stir welding. In order to explain the reasons for their occurrence a short theoretical background of the process is given first. The main emphasis is on the parameters that influence the process. An energy supply based division of defects into three disjoint groups was used. The occurring defects are demonstrated on various materials.

  6. Workmanship standards for fusion welding (United States)

    Phillips, M. D.


    Workmanship standards manual defines practices, that adhere to rigid codes and specifications, for fusion welding of component piping, assemblies, and systems. With written and pictorial presentations, it is part of the operating procedure for fusion welding.

  7. Welding and Brazing Silicon Carbide (United States)

    Moore, T. J.


    Hot isostatic pressing and conventional furnace brazing effective under right conditions. Study performed showed feasibility of welding SiC using several welding and brazing techniques. Use of SiC improves engine efficiency by allowing increase in operating temperature. SiC successfully hot-pressure-welded at 3,550 degrees F (1,950 degrees C) in argon. Refinements of solid-state welding and brazing procedures used sufficient for some specific industrial applications.

  8. Self-Reacting Friction Stir Welding for Aluminum Alloy Circumferential Weld Applications (United States)

    Bjorkman, Gerry; Cantrell, Mark; Carter, Robert


    Friction stir welding is an innovative weld process that continues to grow in use, in the commercial, defense, and space sectors. It produces high quality and high strength welds in aluminum alloys. The process consists of a rotating weld pin tool that plasticizes material through friction. The plasticized material is welded by applying a high weld forge force through the weld pin tool against the material during pin tool rotation. The high weld forge force is reacted against an anvil and a stout tool structure. A variation of friction stir welding currently being evaluated is self-reacting friction stir welding. Self-reacting friction stir welding incorporates two opposing shoulders on the crown and root sides of the weld joint. In self-reacting friction stir welding, the weld forge force is reacted against the crown shoulder portion of the weld pin tool by the root shoulder. This eliminates the need for a stout tooling structure to react the high weld forge force required in the typical friction stir weld process. Therefore, the self-reacting feature reduces tooling requirements and, therefore, process implementation costs. This makes the process attractive for aluminum alloy circumferential weld applications. To evaluate the application of self-reacting friction stir welding for aluminum alloy circumferential welding, a feasibility study was performed. The study consisted of performing a fourteen-foot diameter aluminum alloy circumferential demonstration weld using typical fusion weld tooling. To accomplish the demonstration weld, weld and tack weld development were performed and fourteen-foot diameter rings were fabricated. Weld development consisted of weld pin tool selection and the generation of a process map and envelope. Tack weld development evaluated gas tungsten arc welding and friction stir welding for tack welding rings together for circumferential welding. As a result of the study, a successful circumferential demonstration weld was produced leading

  9. Welding. Performance Objectives. Basic Course. (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…

  10. Welding. Performance Objectives. Intermediate Course. (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)…

  11. Friction stir welding tool and process for welding dissimilar materials (United States)

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


    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.

  12. Ultrasonic Evaluation of Weld Strength for Aluminum Ultrasonic Spot Welds (United States)

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


    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.

  13. Weld bead profile of laser welding dissimilar joints stainless steel (United States)

    Mohammed, Ghusoon R.; Ishak, M.; Aqida, S. N.; Abdulhadi, Hassan A.


    During the process of laser welding, the material consecutively melts and solidifies by a laser beam with a peak high power. Several parameters such as the laser energy, pulse frequency, pulse duration, welding power and welding speed govern the mode of the welding process. The aim of this paper is to investigate the effect of peak power, incident angle, and welding speed on the weld bead geometry. The first investigation in this context was conducted using 2205-316L stainless steel plates through the varying of the welding speed from 1.3 mm/s to 2.1 mm/s. The second investigation was conducted by varying the peak power from 1100 W to 1500 W. From the results of the experiments, the welding speed and laser power had a significant effect on the geometry of the weld bead, and the variation in the diameter of the bead pulse-size. Due to the decrease in the heat input, welding speed affected penetration depth more than bead width, and a narrow width of heat affected zone was achieved ranging from 0.2 to 0.5 mm. Conclusively, weld bead geometry dimensions increase as a function of peak power; at over 1350 W peak power, the dimensions lie within 30 μm.

  14. Weld Nugget Temperature Control in Thermal Stir Welding (United States)

    Ding, R. Jeffrey (Inventor)


    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).

  15. 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...... stress is also taken into account.Work carried out:With few means it is possible to define a thermal model which describes the thermal field from the welding process in reasonable agreement with reality. Identical results are found with ABAQUS and Rosenthal’s analytical solution of the governing heat...... transfer equation under same conditions. It is relative easy tointroduce boundary conditions such as convection and radiation where not surprisingly the radiation has the greatest influence especially from the high temperature regions in the weld pool and the heat affected zone.Due to the large temperature...

  16. Extravehicular activity welding experiment (United States)

    Watson, J. Kevin


    The In-Space Technology Experiments Program (INSTEP) provides an opportunity to explore the many critical questions which can only be answered by experimentation in space. The objective of the Extravehicular Activity Welding Experiment definition project was to define the requirements for a spaceflight experiment to evaluate the feasibility of performing manual welding tasks during EVA. Consideration was given to experiment design, work station design, welding hardware design, payload integration requirements, and human factors (including safety). The results of this effort are presented. Included are the specific objectives of the flight test, details of the tasks which will generate the required data, and a description of the equipment which will be needed to support the tasks. Work station requirements are addressed as are human factors, STS integration procedures and, most importantly, safety considerations. A preliminary estimate of the cost and the schedule for completion of the experiment through flight and postflight analysis are given.

  17. Pulsed welding plasma source (United States)

    Knyaz'kov, A.; Pustovykh, O.; Verevkin, A.; Terekhin, V.; Shachek, A.; Tyasto, A.


    It is shown that in order to form the current pulse of a near rectangular shape, which provides conversion of the welding arc into a dynamic mode, it is rational to connect a forming element made on the basis of an artificial forming line in series to the welding DC circuit. The paper presents a diagram of a pulsed device for welding with a non-consumable electrode in argon which was developed using the forming element. The conversion of the arc into the dynamic mode is illustrated by the current and voltage oscillograms of the arc gap and the dynamic characteristic of the arc within the interval of one pulse generation time in the arc gap. The background current travels in the interpulse interval.

  18. Ternary gas plasma welding torch (United States)

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


    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.

  19. 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.


    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

  20. Sensor integration for robotic laser welding processes

    NARCIS (Netherlands)

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


    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,

  1. Acoustic-Emission Weld-Penetration Monitor (United States)

    Maram, J.; Collins, J.


    Weld penetration monitored by detection of high-frequency acoustic emissions produced by advancing weld pool as it melts and solidifies in workpiece. Acoustic emission from TIG butt weld measured with 300-kHz resonant transducer. Rise in emission level coincides with cessation of weld penetration due to sudden reduction in welding current. Such monitoring applied to control of automated and robotic welders.

  2. Weld procedure development with OSLW - optimization software for laser welding

    Energy Technology Data Exchange (ETDEWEB)

    Fuerschbach, P.W.; Eisler, G.R. [Sandia National Labs., Albuquerque, NM (United States); Steele, R.J. [Naval Air Warfare Center, China Lake, CA (United States)


    Weld procedure development can require extensive experimentation, in-depth process knowledge, and is further complicated by the fact that there are often multiple sets of parameters that will meet the weld requirements. Choosing among these multiple weld procedures can be hastened with computer models that find parameters to meet selected weld dimensional requirements while simultaneously optimizing important figures of merit. Software is described that performs this task for CO{sub 2} laser beam welding. The models are based on dimensionless parameter correlations that are derived from solutions to the moving heat source equations. The use of both handbook and empirically verified thermophysical property values allows OSLW to be extended to many different materials. Graphics displays show the resulting solution on contour plots that can be used to further probe the model. The important figures of merit for laser beam welding are energy transfer efficiency and melting efficiency. The application enables the user to input desired weld shape dimensions, select the material to be welded, and to constrain the search problem to meet the application requirements. Successful testing of the software at a laser welding fabricator has validated this tool for weld procedure development.

  3. Welding. Student Learning Guide. (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…

  4. Thermal Stresses in Welding

    DEFF Research Database (Denmark)

    Hansen, Jan Langkjær


    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...

  5. Elementary TIG Welding Skills. (United States)

    Pierson, John E., III

    The text was prepared to help deaf students develop the skills needed by an employed welder. It uses simplified language and illustrations to present concepts which should be reinforced by practical experience with welding skills. Each of the 12 lessons contains: (1) an information section with many illustrations which presents a concept or…

  6. SHADOW: a new welding technique (United States)

    Kramer, Thorsten; Olowinsky, Alexander M.; Durand, Friedrich


    The new welding technique 'SHADOW ' is introduced. SHADOW means the use of a single pulse to generate a quasi continuous weld of several millimeters in length. HET processing time is defined by the pulse duration of the pulsed laser. At present, a state-of-the-art laser is capable of a maximum pulse duration of 20 ms. The variation of the laser power depend on time is a vital capability of the pulsed laser to adapt the energy deposition into the workpiece. Laser beam welds of several watch components were successfully performed. Similar metals like crowns and axes made out of stainless steel have been welded using pulsed laser radiation. Applying a series of about 130 single pulses for the crown-axis combination the total energy accumulates to 19.5 J. The use of the SHADOW welding technique reduces the energy to 2.5 J. While welding dissimilar metals like stainless steel and bras, the SHADOW welding reduces drastically the contamination as well as the distortion. Laser beam welding of copper has a low process reliability due to the high reflection and the high thermal conductivity. SHADOW welds of 3.6 mm length were performed on 250 micrometers thick copper plates with very high reproducibility. As a result, a pilot plant for laser beam welding of copper plates has been set up. The work to be presented has partly been funded by the European Commission in a project under the contract BRPR-CT-0634.

  7. Finite element modelling of electric currents in AC submerged arc furnaces

    CSIR Research Space (South Africa)

    Mc Dougall, I


    Full Text Available . ANSYS/Multiphysics was used to predict the current density distribution in the electrodes, raw material, slag and molten metal as a result of the three phases AC current. The effect of the electrode immersion on the current path was studied...

  8. 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)


    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.

  9. In-field Welding and Coating Protocols (United States)


    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...

  10. Closed circuit TV system monitors welding operations (United States)

    Gilman, M.


    TV camera system that has a special vidicon tube with a gradient density filter is used in remote monitoring of TIG welding of stainless steel. The welding operations involve complex assembly welding tools and skates in areas of limited accessibility.

  11. Factors affecting weld root morphology in laser keyhole welding (United States)

    Frostevarg, Jan


    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.

  12. Dynamics of space welding impact and corresponding safety welding study. (United States)

    Fragomeni, James M; Nunes, Arthur C


    This study was undertaken in order to be sure that no hazard would exist from impingement of hot molten metal particle detachments upon an astronauts space suit during any future electron beam welding exercises or experiments. The conditions under which molten metal detachments might occur in a space welding environment were analyzed. The safety issue is important during welding with regards to potential molten metal detachments from the weld pool and cold filler wire during electron beam welding in space. Theoretical models were developed to predict the possibility and size of the molten metal detachment hazards during the electron beam welding exercises at low earth orbit. Some possible ways of obtaining molten metal drop detachments would include an impulse force, or bump, to the weld sample, cut surface, or filler wire. Theoretical models were determined for these detachment concerns from principles of impact and kinetic energies, surface tension, drop geometry, surface energies, and particle dynamics. A weld pool detachment parameter for specifying the conditions for metal weld pool detachment by impact was derived and correlated to the experimental results. The experimental results were for the most part consistent with the theoretical analysis and predictions. c2003 Elsevier Ltd. All rights reserved.

  13. Dynamics of space welding impact and corresponding safety welding study (United States)

    Fragomeni, James M.; Nunes, Arthur C.


    This study was undertaken in order to be sure that no hazard would exist from impingement of hot molten metal particle detachments upon an astronauts space suit during any future electron beam welding exercises or experiments. The conditions under which molten metal detachments might occur in a space welding environment were analyzed. The safety issue is important during welding with regards to potential molten metal detachments from the weld pool and cold filler wire during electron beam welding in space. Theoretical models were developed to predict the possibility and size of the molten metal detachment hazards during the electron beam welding exercises at low earth orbit. Some possible ways of obtaining molten metal drop detachments would include an impulse force, or bump, to the weld sample, cut surface, or filler wire. Theoretical models were determined for these detachment concerns from principles of impact and kinetic energies, surface tension, drop geometry, surface energies, and particle dynamics. A weld pool detachment parameter for specifying the conditions for metal weld pool detachment by impact was derived and correlated to the experimental results. The experimental results were for the most part consistent with the theoretical analysis and predictions.

  14. Fundamental Laser Welding Process Investigations

    DEFF Research Database (Denmark)

    Bagger, Claus; Olsen, Flemming Ove


    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...

  15. Pulsed ultrasonic stir welding system (United States)

    Ding, R. Jeffrey (Inventor)


    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.

  16. 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


    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 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...... 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...

  17. Pulsed ultrasonic stir welding method (United States)

    Ding, R. Jeffrey (Inventor)


    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.

  18. Reconditioning medical prostheses by welding (United States)

    Rontescu, C.; Cicic, D. T.; Vasile, I. M.; Bogatu, A. M.; Amza, C. G.


    After the technological process of making, some of the medical prostheses may contain imperfections, which can lead to framing the product in the spoilage category. This paper treats the possibility of reconditioning by welding of the prosthesis made of titanium alloys. The paper presents the obtained results after the reconditioning by welding, using the GTAW process, of a intramedullary rod type prosthesis in which was found a crack after the non-destructive examination. The obtained result analysis, after the micrographic examination of the welded joint areas, highlighted that the process of reconditioning by welding can be applied successfully in such situations.

  19. Portable electron beam weld chamber (United States)

    Lewis, J. R.; Dimino, J. M.


    Development and characteristics of portable vacuum chamber for skate type electron beam welding are discussed. Construction and operational details of equipment are presented. Illustrations of equipment are provided.

  20. Gas Metal Arc Welding. Welding Module 5. Instructor's Guide. (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…

  1. [New welding processes and health effects of welding]. (United States)

    La Vecchia, G Marina; Maestrelli, Piero


    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.

  2. Modeling Stress-Strain State in Butt-Welded Joints after TIG Welding

    Directory of Open Access Journals (Sweden)

    V. Atroshenko


    Full Text Available In this paper mathematical model was developed for definition of thermal-welding cycle influence on welding deformations distribution in flat samples of austenitic steels after TIG welding and developed recommendations to reduce the welding deformation on o the machinery for welding with a copper backing.

  3. Welding--Trade or Profession? (United States)

    Albright, C. E.; Smith, Kenneth


    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…

  4. Metal Working and Welding Operations. (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,…

  5. Weld bonding of stainless steel

    DEFF Research Database (Denmark)

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


    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...

  6. 29 CFR 1910.255 - Resistance welding. (United States)


    ... 29 Labor 5 2010-07-01 2010-07-01 false Resistance welding. 1910.255 Section 1910.255 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Welding, Cutting and Brazing § 1910.255 Resistance welding. (a.... Ignitron tubes used in resistance welding equipment shall be equipped with a thermal protection switch. (3...

  7. 46 CFR 154.660 - Pipe welding. (United States)


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

  8. 49 CFR 179.300-9 - Welding. (United States)


    ... 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...


    DEFF Research Database (Denmark)


    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...

  10. Magnetic Deflection Of Welding Electron Beam (United States)

    Malinzak, R. Michael; Booth, Gary N.


    Electron-beam welds inside small metal parts produced with aid of magnetic deflector. Beam redirected so it strikes workpiece at effective angle. Weld joint positioned to where heavy microfissure concentration removed when subsequent machining required, increasing likelihood of removing any weld defects located in face side of electron-beam weld.

  11. Clamp and Gas Nozzle for TIG Welding (United States)

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


    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.

  12. Research on stress corrosion behavior of CCSE40 welded by underwater wet welding with austenitic welding rod in seawater (United States)

    Zou, Y.; Bai, Q.; Dong, S.; Yang, Z. L.; Gao, Y.


    The stress corrosion behavior of CCSE40 welded by underwater wet welding with austenitic welding rod in seawater was studied. Microstructure, mechanical property and stress corrosion cracking susceptibility of the underwater wet welding joint were analyzed by metallographic observation, tensile and bending tests, slow strain rate test (SSRT) and SEM. The results indicated that the weld zone (WZ) and the heat affected zone (HAZ) were all sensitive to the stress corrosion, and the WZ was more sensitive than the HAZ.

  13. Research on the Effects of Technical Parameters on the Molding of the Weld by A-TIG Welding


    Shi, Kai; Pan, Wu


    The effects of welding parameters on the molding of weld by A-TIG welding of a 4mm thickness mild steel plate is studied in the present paper. The results obtained show that: as welding current increases A-TIG welding penetration gets deeper than TIG welding; size and shape of HAZ has remarkable change; A-TIG welding has the narrower weld pool width than TIG welding.

  14. Automatic welding of stainless steel tubing (United States)

    Clautice, W. E.


    The use of automatic welding for making girth welds in stainless steel tubing was investigated as well as the reduction in fabrication costs resulting from the elimination of radiographic inspection. Test methodology, materials, and techniques are discussed, and data sheets for individual tests are included. Process variables studied include welding amperes, revolutions per minute, and shielding gas flow. Strip chart recordings, as a definitive method of insuring weld quality, are studied. Test results, determined by both radiographic and visual inspection, are presented and indicate that once optimum welding procedures for specific sizes of tubing are established, and the welding machine operations are certified, then the automatic tube welding process produces good quality welds repeatedly, with a high degree of reliability. Revised specifications for welding tubing using the automatic process and weld visual inspection requirements at the Kennedy Space Center are enumerated.

  15. Automatic welding systems for large ship hulls (United States)

    Arregi, B.; Granados, S.; Hascoet, JY.; Hamilton, K.; Alonso, M.; Ares, E.


    Welding processes represents about 40% of the total production time in shipbuilding. Although most of the indoor welding work is automated, outdoor operations still require the involvement of numerous operators. To automate hull welding operations is a priority in large shipyards. The objective of the present work is to develop a comprehensive welding system capable of working with several welding layers in an automated way. There are several difficulties for the seam tracking automation of the welding process. The proposed solution is the development of a welding machine capable of moving autonomously along the welding seam, controlling both the position of the torch and the welding parameters to adjust the thickness of the weld bead to the actual gap between the hull plates.

  16. Modeling of Thermel Transport for GMAW

    Directory of Open Access Journals (Sweden)

    Aniruddha Ghosh


    Full Text Available Investigation of temperature distribution of submerged arc welded plates is essential while designing submerged arc welding joint because the key parameter for the change of weld bead geometry dimension, thermal stress, residual stress, tensile stress, hardness, and so forth is heat input, and heat input is the function of temperature distribution of GMAW process. An attempt is made in this paper to find out the exact solution of the thermal field induced in a semi-infinite body by a moving heat source with Gaussian distribution by selecting appropriate inside volume for submerged arc welding process. It has been revealed that for GMAW, best suitable heat source shape is a combination of semispherical and semioval.

  17. Microstructure and Mechanical Properties of an Ultrasonic Spot Welded Aluminum Alloy: The Effect of Welding Energy

    National Research Council Canada - National Science Library

    He Peng; Daolun Chen; Xianquan Jiang


    The aim of this study is to evaluate the microstructures, tensile lap shear strength, and fatigue resistance of 6022-T43 aluminum alloy joints welded via a solid-state welding technique-ultrasonic spot welding (USW...

  18. Versatile Friction Stir Welding/Friction Plug Welding System (United States)

    Carter, Robert


    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.

  19. Real time computer controlled weld skate (United States)

    Wall, W. A., Jr.


    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.

  20. Corrosion Properties of Laser Welded Stainless Steel

    DEFF Research Database (Denmark)

    Weldingh, Jakob; Olsen, Flemmming Ove


    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)....

  1. Control of Welding Processes. (United States)


    Structures, Office of Deputy Under Secretary of Defense for R&E (ET), Department of Defense, Washington, D.C. CHARLES ZANIS, Assistant Director for Platform... CHARLES NULL, Head, Metals Branch, Naval Sea Systems Command, Washington, D.C. ROBERT A. WEBER, Welding Engineering and Metallurgy, U.S. Army Corps of...Needs. Pp. 487-90. in Papers Presented at the August 3-8, 1Q80, AIME Syi,.posium. Essers, W . ., and R. Walter. Heat transfer and penet ration

  2. The effect of friction welding self-regulation process on weld structure and hardness

    Directory of Open Access Journals (Sweden)

    W. Ptak


    Full Text Available The self-regulation phenomenon that occurs during friction welding process was characterised, and the effect of the self-regulation of theenergy-related parameters on structure and hardness distribution in SW7Mo steel – 55 steel welded joint was determined experimentally.The structure and hardness of the weld zone were examined, the energy required for the stable run of a friction welding process wascalculated, and a relationship between the welding energy and weld hardness was derived.

  3. 10,170 flawless welds

    CERN Multimedia

    Antonella Del Rosso


    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...

  4. Laser welding of fused quartz (United States)

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


    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.

  5. The technology and welding joint properties of hybrid laser-tig welding on thick plate (United States)

    Shenghai, Zhang; Yifu, Shen; Huijuan, Qiu


    The technologies of autogenous laser welding and hybrid laser-TIG welding are used on thick plate of high strength lower alloy structural steel 10CrNiMnMoV in this article. The unique advantages of hybrid laser-TIG welding is summarized by comparing and analyzing the process parameters and welding joints of autogenous laser welding laser welding and hybrid laser-TIG welding. With the optimal process parameters of hybrid welding, the good welding joint without visible flaws can be obtained and its mechanical properties are tested according to industry standards. The results show that the hybrid welding technology has certain advantages and possibility in welding thick plates. It can reduce the demands of laser power, and it is significant for lowering the aspect ratio of weld during hybrid welding, so the gas in the molten pool can rise and escape easily while welding thick plates. Therefore, the pores forming tendency decreases. At the same time, hybrid welding enhances welding speed, and optimizes the energy input. The transition and grain size of the microstructure of hybrid welding joint is better and its hardness is higher than base material. Furthermore, its tensile strength and impact toughness is as good as base material. Consequently, the hybrid welding joint can meet the industry needs completely.

  6. Review of laser hybrid welding

    DEFF Research Database (Denmark)

    Bagger, Claus


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

  7. Novel Process Revolutionizes Welding Industry (United States)


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

  8. Convection in arc weld pools

    Energy Technology Data Exchange (ETDEWEB)

    Oreper, G.M.; Eagar, T.W.; Szekely, J.


    A mathematical model was developed to account for convection and temperature distributions in stationary arc weld pools driven by buoyancy, electromagnetic and surface tension forces. It is shown that the electromagnetic and surface tension forces dominate the flow behavior. In some cases, these forces produce double circulation loops, which are indirectly confirmed by experimental measurements of segregation in the weld pool. It is also shown that the surface tension driven flows are very effective in dissipating the incident energy flux on the pool surface which, in turn, reduces the vaporization from the weld pool.

  9. Plasticity Theory of Fillet Welds

    DEFF Research Database (Denmark)

    Hansen, Thomas


    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...

  10. Specification and qualification of welding procedures for metallic materials : welding procedure test : part 1 : arc and gas welding of steels and arc welding of nickel and nickel alloys : technical corrigendum 1

    CERN Document Server

    International Organization for Standardization. Geneva


    Specification and qualification of welding procedures for metallic materials : welding procedure test : part 1 : arc and gas welding of steels and arc welding of nickel and nickel alloys : technical corrigendum 1

  11. Automated Variable-Polarity Plasma-Arc Welding (United States)

    Numes, A. C., Jr.; Bayless, E. O., Jr.; Jones, S. C., III; Munafo, P.; Munafo, A.; Biddle, A.; Wilson, W.


    Variable-polarity plasma-arc methods produces better welds at lower cost than gas-shielded tungsten-arc welding in assemblies. Weld porosity very low and costs of joint preparation, depeaking, inspection, and weld repair minimized.

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

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Z. (Nuclear Engineering Division)


    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.

  13. Materials participation in welded joints manufacturing (United States)

    Ghenghea, L. D.


    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.

  14. Filler wire for aluminum alloys and method of welding (United States)

    Bjorkman, Jr., Gerald W. O. (Inventor); Cho, Alex (Inventor); Russell, Carolyn K. (Inventor)


    A weld filler wire chemistry has been developed for fusion welding 2195 aluminum-lithium. The weld filler wire chemistry is an aluminum-copper based alloy containing high additions of titanium and zirconium. The additions of titanium and zirconium reduce the crack susceptibility of aluminum alloy welds while producing good weld mechanical properties. The addition of silver further improves the weld properties of the weld filler wire. The reduced weld crack susceptibility enhances the repair weldability, including when planishing is required.

  15. MFDC - technological improvement in resistance welding controls

    Energy Technology Data Exchange (ETDEWEB)

    Somani, A.K.; Naga Bhaskar, V.; Chandramouli, J.; Rameshwara Rao, A. [Nuclear Fuel Complex, Dept. of Atomic Energy, Hyderabad (India)


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

  16. Gas Shielding Technology for Welding and Brazing (United States)

    Nunes, Arthur J.; Gradl, Paul R.


    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."

  17. Welding and Production Metallurgy Facility (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...

  18. Thermomechanical Modelling of Resistance Welding

    DEFF Research Database (Denmark)

    Bay, Niels; Zhang, Wenqi


    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...

  19. Laser Welding of Ship Steel

    National Research Council Canada - National Science Library

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


    ... 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...

  20. Welding process modelling and control (United States)

    Romine, Peter L.; Adenwala, Jinen A.


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

  1. Automatic Control Of Length Of Welding Arc (United States)

    Iceland, William F.


    Nonlinear relationships among current, voltage, and length stored in electronic memory. Conceptual microprocessor-based control subsystem maintains constant length of welding arc in gas/tungsten arc-welding system, even when welding current varied. Uses feedback of current and voltage from welding arc. Directs motor to set position of torch according to previously measured relationships among current, voltage, and length of arc. Signal paths marked "calibration" or "welding" used during those processes only. Other signal paths used during both processes. Control subsystem added to existing manual or automatic welding system equipped with automatic voltage control.

  2. Ship construction and welding

    CERN Document Server

    Mandal, Nisith R


    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...

  3. Welding of Prosthetic Alloys

    Directory of Open Access Journals (Sweden)

    Wojciechowska M.


    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.

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

    Nunes, A. C., Jr.


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

  5. Upgraded HFIR Fuel Element Welding System

    Energy Technology Data Exchange (ETDEWEB)

    Sease, John D [ORNL


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

  6. A study of processes for welding pipelines

    Energy Technology Data Exchange (ETDEWEB)

    Weston, J. (ed.)


    A review was made of exisiting and potential processes for welding pipelines: fusion welding (arc, electron beam, laser, thermit) and forge welding (friction, flash, magnetically impelled arc butt, upset butt, explosive, shielded active gas, gas pressure). Consideration of J-lay operations gave indications that were reflections of the status of the processes in terms of normal land and offshore S-lay operation: forge welding processes, although having promise require considerable development; fusion welding processes offer several possibilities (mechanized GMA welding likely to be used in 1991-2); laser welding requires development in all pipeline areas: a production machine for electron beam welding will involve high costs. Nondestructive testing techniques are also reviewed. Demand for faster quality assessment is being addressed by speeding radiographic film processing and through the development of real time radiography and automatic ultrasonic testing. Conclusions on most likely future process developments are: SMAW with cellulosic electrodes is best for tie-ins, short pip runs; SMAW continues to be important for small-diameter lines, although mechanized GMA could be used, along with mechanical joining, MIAB, radial fraction, and flash butt; mechanized GMA welding is likely to predominate for large diameter lines and probably will be used for the first J-lay line (other techniques could be used too); and welding of piping for station facilities involves both shop welding of sub-assemblies and on-site welding of pipe and sub-assemblies to each other (site welding uses both SMAW and GMAW). Figs, tabs.

  7. Weld procedure produces quality welds for thick sections of Hastelloy-X (United States)

    Flens, F. J.; Fletcher, C. W.; Glasier, L. F., Jr.


    Welding program produces premium quality, multipass welds in heavy tube sections of Hastelloy-X. It develops semiautomatic tungsten/inert gas procedures, weld wire procurement specifications material weld properties, welder-operator training, and nondestructive testing inspection techniques and procedures.

  8. Laser welding of aluminium-magnesium alloys sheets process optimization and welds characterization

    Energy Technology Data Exchange (ETDEWEB)

    Mayer, C. [GEMPPM (CALFETMAT), 69 - Villeurbanne (France); Fouquet, F. [GEMPPM (CALFETMAT), 69 - Villeurbanne (France); Robin, M. [GEMPPM (CALFETMAT), 69 - Villeurbanne (France)


    The purpose of the present study was to obtain good quality welds using a CO2 laser with Al-Mg alloys sheet. Defects formation mechanisms were analyzed and a welding procedure was defined, using several characterization technics, in order to realize low defects welding seams. After laser welding optimization, comparative tensile tests and microstructural analysis were carried out. (orig.)

  9. Nitrogen And Oxygen Amount In Weld After Welding With Micro-Jet Cooling

    Directory of Open Access Journals (Sweden)

    Węgrzyn T.


    Full Text Available Micro-jet cooling after welding was tested only for MIG welding process with argon, helium and nitrogen as a shielded gases. A paper presents a piece of information about nitrogen and oxygen in weld after micro-jet cooling. There are put down information about gases that could be chosen both for MIG/MAG welding and for micro-jet process. There were given main information about influence of various micro-jet gases on metallographic structure of steel welds. Mechanical properties of weld was presented in terms of nitrogen and oxygen amount in WMD (weld metal deposit.


    Directory of Open Access Journals (Sweden)

    BURCA Mircea


    manual welding tests in the light of using the process for welding surfacing being known that in such applications mechanised operations are recommended whenever possible given the latter strengths i.e. increased productivity and quality deposits. The research also aims at achieving a comparative a study between wire mechanised feed based WIG manual welding and the manual rod entry based manual welding in terms of geometry deposits, deposits aesthetics, operating technique, productivity, etc . In this regard deposits were made by means of two welding procedures, and subsequently welding surfacing was made with the optimum values of the welding parameters in this case.

  11. Effects of welding parameters on the mechanical properties of inert gas welded 6063 Aluminium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ertan, Taner [MAKO Corporation (Turkey); Uguz, Agah [Uludag Univ. (Turkey). Mechnical Engineering Dept.; Ertan, Rukiye


    The influence of welding parameters, namely welding current and gas flow rate, on the mechanical properties of Gas Tungsten Arc Welding (GTAW) and Shielded Metal Arc Welding (SMAW) welded 6063 Aluminum alloy (AA 6063) has been investigated. In order to study the effect of the welding current and gas flow rate, microstructural examination, hardness measurements and room temperature tensile tests have been carried out. The experimental results show that the mechanical properties of GTAW welded joints have better mechanical properties than those of SMAW welded joints. Increasing the welding current appeared to have a beneficial effect on the mechanical properties. However, either increasing or decreasing the gas flow rate resulted in a decrease of hardness and tensile strength. It was also found that, the highest strength was obtained in GTAW welded samples at 220 A and 15 l/min gas flow rate.

  12. Automatic monitoring of vibration welding equipment (United States)

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


    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.

  13. Experimental and simulated strength of spot welds

    DEFF Research Database (Denmark)

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


    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...

  14. Thermal treatment of dissimilar steels' welded joints (United States)

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


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

  15. Closed circuit television welding alignment system

    Energy Technology Data Exchange (ETDEWEB)

    Darner, G.S.


    Closed circuit television (CCTV) weld targeting systems were developed to provide accurate and repeatable positioning of the electrode of an electronic arc welder with respect to the parts being joined. A sliding mirror electrode holder was developed for use with closed circuit television equipment on existing weld fixturing. A complete motorized CCTV weld alignment system was developed to provide weld targeting for even the most critical positioning requirements.

  16. Preventing Contamination In Electron-Beam Welds (United States)

    Goodin, Wesley D.; Gulbrandsen, Kevin A.; Oleksiak, Carl


    Simple expedient eliminates time-consuming, expensive manual hand grinding. Use of groove and backup tube greatly reduces postweld cleanup in some electron-beam welding operations. Tube-backup method developed for titanium parts, configurations of which prevents use of solid-block backup. In new welding configuration, tube inserted in groove to prevent contact between alumina beads and molten weld root. When welding complete and beads and tube removed, only minor spatter remains and is ground away easily.

  17. Performance of mesh seam welds in tailor welded blanks; Terado blank yo mash seam yosetsubu no tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Uchihara, M.; Takahashi, M.; Kurita, M.; Hirose, Y.; Fukui, K. [Sumitomo Metal Industries, Ltd., Osaka (Japan)


    Formability, fatigue properties and corrosion behavior of mash seam welded steel sheets were investigated and the results were compared with laser weld. The stretch formability of mash seam weld and laser weld were same level. Mash seam weld however, showed slightly smaller formability in hole expansion test. The fatigue strength of mash seam welds was lower than that of laser welds in case of differential thickness joints. Corrosion was apt to initiate at weld in both mash seam and laser weld with E-coat. The corrosion resistance of welds was improved by using zinc coated steel. 3 refs., 14 figs., 2 tabs.

  18. Welding technology for rails. Rail no setsugo gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    Okumura, M.; Karimine, K. (Nippon Steel Corp., Tokyo (Japan)); Uchino, K.; Sugino, K. (Nippon Steel Corp., Kitakyushu, Fukuoka (Japan). Technical Research Inst. of Yawata Works); Ueyama, K. (JR Railway Technical Research Inst., Tokyo (Japan))


    The rail joining technology is indispensable for making long welded rails. Flush butt welding, gas welding, enclosed arc welding, and thermit welding are used properly as the welding methods. A method for improving the joint reliability by controlling the residual stress distribution of welded joint is investigated to prepare high carbon component weld metal similar to the rail. Problems with each of the welding methods and the newly developed technology to solve the problems are outlined. Composition of the coating is improved also, and a high C system welding rod is developed which has satisfactory weldability. High performance and high efficient new enclosed arc welding technology not available by now is developed which utilizes high carbon welding metal as a new EA welding work technology, and put to practical use. As a result of this study, useful guides are obtained for the establishment of satisfactory thermit welding technology. 17 refs., 16 figs., 1 tab.

  19. 49 CFR 195.224 - Welding: Weather. (United States)


    ... 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...

  20. 49 CFR 179.100-9 - Welding. (United States)


    ... 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...

  1. 49 CFR 179.220-10 - Welding. (United States)


    ... 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...

  2. 49 CFR 179.400-11 - Welding. (United States)


    ... 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...

  3. 49 CFR 179.200-10 - Welding. (United States)


    ... 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...

  4. 30 CFR 77.408 - Welding operations. (United States)


    ... 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...

  5. 30 CFR 75.1729 - Welding operations. (United States)


    ... 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...

  6. Friction welding thermal and metallurgical characteristics

    CERN Document Server

    Yilbas, Bekir Sami


    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.

  7. Welding Using Chilled-Inert-Gas Purging (United States)

    Mcgee, William F.; Rybicki, Daniel J.


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

  8. 49 CFR 179.11 - Welding certification. (United States)


    ... 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...

  9. 46 CFR 154.665 - Welding procedures. (United States)


    ... 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...

  10. Low Speed Control for Automatic Welding (United States)

    Iceland, W. E.


    Amplifier module allows rotating positioner of automatic welding machine to operate at speeds below normal range. Low speeds are precisely regulated by a servomechanism as are normal-range speeds. Addition of module to standard welding machine makes it unnecessary to purchase new equipment for low-speed welding.

  11. 49 CFR 195.214 - Welding procedures. (United States)


    ... accordance with welding procedures qualified under Section 5 of API 1104 or Section IX of the ASME Boiler and Pressure Vessel Code (incorporated by reference, see § 195.3) . The quality of the test welds used to... 49 Transportation 3 2010-10-01 2010-10-01 false Welding procedures. 195.214 Section 195.214...

  12. Welding multiple plies with an electron beam (United States)

    Kiluk, F. J.


    Method for electron-beam welding of multi-ply metal sheets eliminates ply separation and minimizes porosity. Method was developed for assembling bellows made of four plies of iron/nickel alloy sheets. Method consists of making successive stitch welds with electron beam until weld seam is completely filled in and all plies have been penetrated.

  13. Viewing electron-beam welds in progress (United States)

    Armenoff, C. T.


    With aid of optical filter, operator of electron-beam welding machine can view TV image of joint that is being welded and can make corrections as necessary. Operator can see when weld bead gets out of alinement, for example, and compensate for deflection of electron beam caused by changes in magnetic field.

  14. [Dental welding titanium and its clinical usage]. (United States)

    Li, H; Xiao, M; Zhao, Y


    Due to its excellent biocompatibility, desirable chemical and mechanical properties, Titanium has been used for implant denture, RPD and FPD, where welding techniques were indispensable. This paper introduces 5 useful modern ways to weld Titanium and their clinical usage. They are: laser, plasma welding, TIG, infraned brazing and Hruska electrowelding.

  15. Technology of welding aluminum alloys-III (United States)

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


    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.

  16. 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


    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.

  17. Study on visual image information detection of external angle weld based on arc welding robot (United States)

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


    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.

  18. Contamination and solid state welds.

    Energy Technology Data Exchange (ETDEWEB)

    Mills, Bernice E.


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

  19. Laser welding of selected aerospace alloys (United States)

    Ebadan, Gracie E.

    The study was aimed at developing an understanding of the microstructural effects of the laser welding process on the alloys, and assessing the structural integrity of the resultant welds. The effect of laser processing parameters such as laser power, laser beam traverse speed, lens focal length, and the manipulation of these parameters on the welding efficiency and weld area integrity was also investigated. Other tasks within the project included a study on the possibility of using an anodic film to enhance the laser weld ability of Al 6061. Finally, attempts were made to identify phases observed in the weld area of the composite materials. Nimonics C263 and PE11 exhibited laser welds free of cracks and porosity. The difference in composition between the two alloys did not result in any significant dissimilarities in their response to the laser welding process. The welds in both alloys exhibited a fine columnar dendritic microstructure, and while carbides were observed in the interdendritic regions of the welds, electron optical analysis did not reveal any gamma' precipitates in this region. It was concluded that for the welding of thin gage materials above a threshold laser power the resultant welding efficiency shows a greater dependence on laser beam mode, and laser spot size, than on laser power, and beam traverse speed. Aluminum 6061 was not easily welded with a laser in its as received form, and the welds showed some degree of porosity. Anodizing was found to improve the welding efficiency in this material. While the presence of an anodic film on the metal surface increased the welding efficiency of the alloy, no relationship was found between the thickness of the anodic film and welding efficiency in the range of film thicknesses investigated. Weld regions were observed to be cellular dendritic in structure, with narrow heat affected zones. No precipitates or low melting point phases could be identified in the weld region. Melt zones were successfully

  20. Analysis and Comparison of Aluminum Alloy Welded Joints Between Metal Inert Gas Welding and Tungsten Inert Gas Welding (United States)

    Zhao, Lei; Guan, Yingchun; Wang, Qiang; Cong, Baoqiang; Qi, Bojin


    Surface contamination usually occurs during welding processing and it affects the welds quality largely. However, the formation of such contaminants has seldom been studied. Effort was made to study the contaminants caused by metal inert gas (MIG) welding and tungsten inert gas (TIG) welding processes of aluminum alloy, respectively. SEM, FTIR and XPS analysis was carried out to investigate the microstructure as well as surface chemistry. These contaminants were found to be mainly consisting of Al2O3, MgO, carbide and chromium complexes. The difference of contaminants between MIG and TIG welds was further examined. In addition, method to minimize these contaminants was proposed.

  1. Electron Beam Welding to Join Gamma Titanium Aluminide Articles (United States)

    Kelly, Thomas Joseph (Inventor)


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

  2. Materials and welding engineering in advanced coal utilization plants

    Energy Technology Data Exchange (ETDEWEB)

    Schuhmacher, D.; Schulze-Frielinghaus, W.; Puetz, J.; Eichhorn, F.; Gaever, E. van


    The authors present the findings of studies on welding methods for high-temperature alloys used in advanced coal gasification plants. They discuss weld preparation, automatic TIG welding, MIG welding (also with pulsed arc) and plasma arc welding. The mechanical properties of welded joints before and after age hardening are investigated, and the results of fatigue and corrosion tests are presented. The welding methods are compared with a view to their suitability for high-temperature materials.

  3. Advanced Welding Tool (United States)


    Accutron Tool & Instrument Co.'s welder was originally developed as a tool specifically for joining parts made of plastic or composite materials in any atmosphere to include the airless environment of space. Developers decided on induction or magnetic heating to avoid causing deformation and it also can be used with almost any type of thermoplastic material. Induction coil transfers magnetic flux through the plastic to a metal screen that is sandwiched between the sheets of plastic to be joined. When welder is energized, alternating current produces inductive heating on the screen causing the adjacent plastic surfaces to melt and flow into the mesh, creating a bond on the total surface area. Dave Brown, owner of Great Falls Canoe and Kayak Repair, Vienna, VA, uses a special repair technique based on operation of the Induction Toroid Welder to fix canoes. Whitewater canoeing poses the problem of frequent gashes that are difficult to repair. The main reason is that many canoes are made of plastics. The commercial Induction model is a self-contained, portable welding gun with a switch on the handle to regulate the temperature of the plastic melting screen. Welder has a broad range of applications in the automobile, appliance, aerospace and construction industries.

  4. Effect of weld spacing on microstructure and mechanical properties of CLAM electron beam welding joints

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Yutao; Huang, Bo, E-mail:; Zhang, Junyu; Zhang, Baoren; Liu, Shaojun; Huang, Qunying


    Highlights: • The welded joints of CLAM steel with different weld spacings have been fabricated with electron beam welding, and a simplified model of CLAM sheet was proposed. • The microstructure and mechanical properties such as microhardness, impact and tensile were investigated at different welding spacing for both conditions of as-welded and post weld heat treatment (PWHT). • The effect of the welding thermal cycle was significantly when the weld spacings were smaller than 4 mm. • When the weld spacing was small enough, the original microstructures would be fragmented with the high heat input. - Abstract: China low activation martensitic (CLAM) steel has been chosen as the primary structural material in the designs of dual function lithium-lead (DFLL) blanket for fusion reactors, China helium cooled ceramic breeder (HCCB) test blanket module (TBM) for ITER and China fusion engineering test reactor (CFETR) blanket. The cooling components of the blankets are designed with high density cooling channels (HDCCs) to remove the high nuclear thermal effectively. Hence, the welding spacing among the channels are small. In this paper, the welded joints of CLAM steel with different weld spacings have been fabricated with electron beam welding (EBW). The weld spacing was designed to be 2 mm, 3 mm, 4 mm, 6 mm and 8 mm. The microstructure and mechanical properties such as microhardness, impact and tensile were investigated at different welding spacing for both conditions of as-welded and post weld heat treatment (PWHT). The PWHT is tempering at 740 °C for 120 min. The results showed that the grain size in the heat affected zone (HAZ) increased with the increasing weld spacing, and the joint with small weld spacing had a better performance after PWHT. This work would give useful guidance to improve the preparation of the cooling components of blanket.

  5. Study of Mechanical Properties and Characterization of Pipe Steel welded by Hybrid (Friction Stir Weld + Root Arc Weld) Approach

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Yong Chae [ORNL; Sanderson, Samuel [MegaStir Technologies LLC; Mahoney, Murray [Consultant; Wasson, Andrew J [ExxonMobil, Upstream Research Company (URC); Fairchild, Doug P [ExxonMobil, Upstream Research Company (URC); Wang, Yanli [ORNL; Feng, Zhili [ORNL


    Friction stir welding (FSW) has recently attracted attention as an alternative construction process for gas/oil transportation applications due to advantages compared to fusion welding techniques. A significant advantage is the ability of FSW to weld the entire or nearly the entire wall thickness in a single pass, while fusion welding requires multiple passes. However, when FSW is applied to a pipe or tube geometry, an internal back support anvil is required to resist the plunging forces exerted during FSW. Unfortunately, it may not be convenient or economical to use internal backing support due to limited access for some applications. To overcome this issue, ExxonMobil recently developed a new concept, combining root arc welding and FSW. That is, a root arc weld is made prior to FSW that supports the normal loads associated with FSW. In the present work, mechanical properties of a FSW + root arc welded pipe steel are reported including microstructure and microhardness.

  6. Metal vaporization from weld pools (United States)

    Block-Bolten, A.; Eagar, T. W.


    Experimental studies of alloy vaporization from aluminum and stainless steel weld pools have been made in order to test a vaporization model based on thermodynamic data and the kinetic theory of gases. It is shown that the model can correctly predict the dominant metal vapors that form but that the absolute rate of vaporization is not known due to insufficient knowledge of the surface temperature distribution and subsequent condensation of the vapor in the cooler regions of the metal. Values of the net evaporation rates for different alloys have been measured and are found to vary by two orders of magnitude. Estimated maximum weld pool temperatures based upon the model are in good agreement with previous experimental measurements of electron beam welds.



    Dhananjay Kumar*, Dharamvir mangal


    The effect of welding process on the distortion with 304L stainless steel 12thk weld joints made by TIG (tungsten inert gas) and SMAW (Shielded metal arc welding) welding process involving different type joint configuration have been studied. The joint configurations employed were double V-groove edge preparation for double side SMAW welding and square – butt preparation for double side TIG welding. All weld joints passed by radiographic. Distortion measurements were carried out using height ...

  8. Peculiarities and future development of space welding (United States)

    Shulym, V. F.; Lapchinskii, V. F.; Nikitskii, V. P.; Demidov, D. L.; Neznamova, L. O.

    The paper deals with the peculiar features of space as a medium in which welding operations are performed. Studies of different methods of welding carried out both in the plane-laboratory and in space are briefly described, and the comparative characteristics of the most promising methods of welding for space conditions are given. The selection of electron beam as a basic method for space is supported. The paper considers the main welding processes performed in space with the help of an electron beam, such as heating, brazing, welding, cutting and coating.

  9. Grain refinement control in TIG arc welding (United States)

    Iceland, W. F.; Whiffen, E. L. (Inventor)


    A method for controlling grain size and weld puddle agitation in a tungsten electrode inert gas welding system to produce fine, even grain size and distribution is disclosed. In the method the frequency of dc welding voltage pulses supplied to the welding electrode is varied over a preselected frequency range and the arc gas voltage is monitored. At some frequency in the preselected range the arc gas voltage will pass through a maximum. By maintaining the operating frequency of the system at this value, maximum weld puddle agitation and fine grain structure are produced.

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

    Directory of Open Access Journals (Sweden)

    Jan PIWNIK


    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.

  11. Experimental Study of the Redistribution of Welding Distortion According to the Partial Removal of Welded Structure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yong Rae; Wang, Chao; Kim, Jae Woong [Yeungnam University, Kyungsan (Korea, Republic of)


    During the welding process, welding distortion is caused by the non-uniformity of the temperature distribution in the weldment. Welding distortion is redistributed because the residual stress and rigidity change according to the removal of the welded structure. In shipbuilding in particular, this phenomenon may be observed during the cutting process of lugs that are attached to blocks for transfer. The redistribution of welding distortion also causes problems, such as damage to the cutting tool. The aim of this study is to experimentally analyze the redistribution of welding distortion because of the partial removal of the welded structure. In the experiments conducted in this study, fillet welding and cutting were performed, and longitudinal bending and angular distortion in the welded structures were then investigated and analyzed.


    Directory of Open Access Journals (Sweden)

    Nachimani Charde


    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.

  13. Experimental investigation on the weld pool formation process in plasma keyhole arc welding (United States)

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


    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.

  14. Residual stress characterization of welds and post-weld processes using x-ray diffraction techniques (United States)

    Brauss, Michael E.; Pineault, James A.; Eckersley, John S.


    This paper illustrates the importance of residual stress characterization in welds and post weld processes. The failure to characterize residual stresses created during welding and/or post weld processes can lead to unexpected occurrences of stress corrosion cracking, distortion, fatigue cracking as well as instances of over design or over processing. The development of automated residual stress mapping and the availability of portable and fast equipment have now made the characterization of residual stresses using x-ray diffraction practical for process control and optimization. The paper presents examples where x-ray diffraction residual stress characterization techniques were applied on various kinds of welds including arc welds, TIG welds, resistance welds, laser welds and electron beam welds. The nondestructive nature of the x-ray diffraction technique has made the residual stress characterization of welds a useful tool for process optimization and failure analysis, particularly since components can be measured before and after welding and post welding processes. Some examples presented show the residual stresses before and after the application of post weld processes such as shot peening, grinding and heat treatment.

  15. Weld-brazing of titanium (United States)

    Bales, T. T.; Royster, D. M.; Arnold, W. E., Jr.


    A joining process, designated weld-brazing, which combines resistance spotwelding and brazing has been developed at the NASA Langley Research Center. Resistance spot-welding is employed to position and align the parts and to establish a suitable faying surface gap for brazing; it contributes to the integrity of the joint. Brazing enhances the properties of the joint and reduces the stress concentrations normally associated with spotwelds. Ti-6Al-4V titanium alloy joints have been fabricated using 3003 aluminum braze both in a vacuum furnace and in a retort containing an inert gas environment.

  16. Shimmed electron beam welding process (United States)

    Feng, Ganjiang; Nowak, Daniel Anthony; Murphy, John Thomas


    A modified electron beam welding process effects welding of joints between superalloy materials by inserting a weldable shim in the joint and heating the superalloy materials with an electron beam. The process insures a full penetration of joints with a consistent percentage of filler material and thereby improves fatigue life of the joint by three to four times as compared with the prior art. The process also allows variable shim thickness and joint fit-up gaps to provide increased flexibility for manufacturing when joining complex airfoil structures and the like.

  17. Laser welding of micro plastic parts (United States)

    Haberstroh, E.; Hoffmann, W.-M.


    Most welding processes for plastics do not meet the demands of micro technology and thus cannot be applied in this innovative industrial sector. One of the few techniques which are applicable in this sector is the laser transmission welding, which has distinctive advantages like low mechanical and thermal load of the joining parts. This makes the laser particularly suitable for the welding of micro plastics parts. Thereby, contour welding is a process variant of laser transmission welding enabling the welding of complex and even three-dimensional weld contours. But so far it has not yet been applied for welding plastics parts of micro scale in the industrial practice. Recent research at the Institute of Plastics Processing (IKV) at the RWTH Aachen University shows the feasibility of this process to weld small and complex micro parts. Good mechanical properties can be achieved. However, it is necessary to apply measures to reduce the formation of flash. Moreover, it can be shown that there is a strong influence of some material parameters on the laser welding process so that some plastics are more suitable than others for the contour welding in micro technology.

  18. TIG welding power supply with improved efficiency

    Directory of Open Access Journals (Sweden)

    Сергій Володимирович Гулаков


    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

  19. Experimental analysis of cut welding in aluminium

    DEFF Research Database (Denmark)

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


    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....

  20. Welding of gamma titanium aluminide alloys (United States)

    Smashey, Russell W. (Inventor); Kelly, Thomas J. (Inventor); Snyder, John H. (Inventor); Sheranko, Ronald L. (Inventor)


    An article made of a gamma titanium aluminide alloy is welded, as for example in the weld repair of surface cracks, by removing foreign matter from the area to be welded, first stress relieving the article, cooling the entire article to a welding temperature of from about F. to about F., welding a preselected region in an inert atmosphere at the welding temperature, and second stress relieving the article. Welding is preferably accomplished by striking an arc in the preselected region so as to locally melt the alloy in the preselected region, providing a filler metal having the same composition as the gamma titanium aluminide alloy of the article, and feeding the filler metal into the arc so that the filler metal is melted and fused with the article to form a weldment upon solidification.

  1. Numerical Simulation of Duplex Steel Multipass Welding

    Directory of Open Access Journals (Sweden)

    Giętka T.


    Full Text Available Analyses based on FEM calculations have significantly changed the possibilities of determining welding strains and stresses at early stages of product design and welding technology development. Such an approach to design enables obtaining significant savings in production preparation and post-weld deformation corrections and is also important for utility properties of welded joints obtained. As a result, it is possible to make changes to a simulated process before introducing them into real production as well as to test various variants of a given solution. Numerical simulations require the combination of problems of thermal, mechanical and metallurgical analysis. The study presented involved the SYSWELD software-based analysis of GMA welded multipass butt joints made of duplex steel sheets. The analysis of the distribution of stresses and displacements were carried out for typical welding procedure as during real welding tests.

  2. Residual stress simulation of circumferential welded joints

    Directory of Open Access Journals (Sweden)

    Melicher R.


    Full Text Available Residual stresses are an important consideration in the component integrity and life assessment of welded structure. The welding process is very complex time dependent physical phenomenon with material nonlinearity. The welding is a thermal process with convection between fluid flow and welding body, between welding bodyand environment. Next type of boundary conditions is radiation and thermo-mechanical contact on the outer surface of gas pipe in the near of weld. The temperature variation so obtained is utilised to find the distribution of the stress field.In this paper, a brief review of weld simulation and residual stress modelling using the finite element method (FEM by commercial software ANSYS is presented. Thermo-elastic-plastic formulations using a von Mises yield criterion with nonlinear kinematics hardening has been employed. Residual axial and hoop stresses obtained from the analysis have been shown. The commercial FEM code ANSYS was used for coupled thermalmechanical analysis.

  3. Yield load solutions of heterogeneous welded joints

    Energy Technology Data Exchange (ETDEWEB)

    Kozak, D., E-mail: dkozak@sfsb.h [Mechanical Engineering Faculty in Slavonski Brod, Josip Juraj Strossmayer University of Osijek, Trg Ivane Brlic-Mazuranic 2, Hr-35000 Slavonski Brod (Croatia); Gubeljak, N. [Faculty of Mechanical Engineering, University of Maribor, Smetanova 17, SI-2000 Maribor (Slovenia); Konjatic, P.; Sertic, J. [Mechanical Engineering Faculty in Slavonski Brod, Josip Juraj Strossmayer University of Osijek, Trg Ivane Brlic-Mazuranic 2, Hr-35000 Slavonski Brod (Croatia)


    The aim of this paper is to establish yield load solutions when the materials inhomogeneity within the weld is present, which is usually the case in repair welding. The effect of yield strength mismatch of welded joints performed with different geometry on the yield load value has been investigated in the context of single edge notched fracture toughness specimen subjected to bending SE(B) using the finite element method. The crack was located in the center of the weld and the two most important geometrical parameters were identified as: crack length ratio a/W as well as slenderness of the welded joint, which were systematically varied. One practical and four additional combinations of filler materials, with the same portion of overmatched part and undermatched part of the weld, were analyzed, and plane strain FE solutions for the case when the crack is located in the overmatched half of the heterogeneous weld were obtained.

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

    Directory of Open Access Journals (Sweden)

    Hadryś D.


    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.

  5. A Brief Introduction to the Theory of Friction Stir Welding (United States)

    Nunes, Arthur C., Jr.


    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.

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


    Hadryś D.


    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...

  7. 49 CFR 192.235 - Preparation for welding. (United States)


    ... 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...

  8. Advanced Control Methods for Optimization of Arc Welding

    DEFF Research Database (Denmark)

    Thomsen, J. S.

    Gas Metal Arc Welding (GMAW) is a proces used for joining pieces of metal. Probably, the GMAW process is the most successful and widely used welding method in the industry today. A key issue in welding is the quality of the welds produced. The quality of a weld is influenced by several factors in...

  9. Mathematical Model Of Variable-Polarity Plasma Arc Welding (United States)

    Hung, R. J.


    Mathematical model of variable-polarity plasma arc (VPPA) welding process developed for use in predicting characteristics of welds and thus serves as guide for selection of process parameters. Parameters include welding electric currents in, and durations of, straight and reverse polarities; rates of flow of plasma and shielding gases; and sizes and relative positions of welding electrode, welding orifice, and workpiece.

  10. Analysis of factors affecting fractures of rails welded by alumino-thermic welding




    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.

  11. Nitrogen And Oxygen Amount In Weld After Welding With Micro-Jet Cooling


    Węgrzyn T.; Piwnik J.


    Micro-jet cooling after welding was tested only for MIG welding process with argon, helium and nitrogen as a shielded gases. A paper presents a piece of information about nitrogen and oxygen in weld after micro-jet cooling. There are put down information about gases that could be chosen both for MIG/MAG welding and for micro-jet process. There were given main information about influence of various micro-jet gases on metallographic structure of steel welds. Mechanical properties of weld was pr...

  12. Resistance spot welding of galvanized steel: Part II. Mechanisms of spot weld nugget formation (United States)

    Gedeon, S. A.; Eagar, T. W.


    Dynamic inspection monitoring of the weld current, voltage, resistance, electrode displacement, and force was performed in conjunction with a detailed study of the effects of material variations and weld process parameter modifications on resistance spot welding of coated and uncoated steels. In order to determine the mechanisms of weld nugget formation and growth, scanning electron microscopy photos were taken of the developing nugget. These physical changes were then related to the dynamic inspection curves and the welding current lobe. The effects of material variations and weld process modifications, the results of which were presented in Part I, can be explained through an understanding of these mechanisms.

  13. Mechanics Model of Plug Welding (United States)

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


    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.

  14. Fundamentals of Welding. Teacher Edition. (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…

  15. Electrode cartridge for pulse welding

    Energy Technology Data Exchange (ETDEWEB)

    Bonnen, John Joseph Francis; Golovashchenko, Sergey Fedorovich; Mamutov, Alexander; Maison, Lloyd Douglas


    A cartridge assembly for a tool includes a cartridge body or casing that contains a conductor. A conductor is connected to a pulse generator or source of stored charge that is discharged to vaporize the conductor and create an electro-hydraulic or electro-magnetic shockwave that is used to impact or pulse weld two parts together.

  16. Mixing weld gases offers advantages (United States)

    May, J. L.; Mendenhall, M. M.


    Argon added to helium during gas tungsten arc cover-pass welding in the horizontal position results in a better controlled wider bead width, increased arc stability, and reduction in heat input. Adequate filler material wetness and penetration pass coverage is possible with only one pass.

  17. Welding the CNGS decay tube

    CERN Multimedia

    Maximilien Brice


    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.

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

    Directory of Open Access Journals (Sweden)

    Rajendra Prasad


    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.

  19. Welded joints integrity analysis and optimization for fiber laser welding of dissimilar materials (United States)

    Ai, Yuewei; Shao, Xinyu; Jiang, Ping; Li, Peigen; Liu, Yang; Liu, Wei


    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.

  20. Intelligent hybrid system of welding parameters for robotic arc-welding task-level offline programming (United States)

    Peng, Pai; Tian, Jiansong; Wu, Lin; Dai, Ming


    Welding process parameters are indispensable to program arc welding robot. To simplify off-line programming (OLP) for robotic arc welding, we develop an arc welding expert system whcih can generate welding process parameters automatically. Its input data came from the feature database of welding part, which is set up by our feature modeling system. The expert system has become an important module of our RAWTOLPS (Robotic Arc Welding Task-level Off-Line System). It combines case-based reasoning with heuristic rule-based reasoning methods to deal with the welding process design. Moreover, artificial neural networks are introduced to the systems for reasoning and machine learning, and several network modules are developed to learn from welding process database, based on back-propagation neural networks. After some groups of actual welding process data were used to train the network models, several network models are established to both design the welding process and to predict the weld bead shape. Besides the ANN-based learning, cased-based learning are used in the expert system. These two methods have respectively their own characteristics, and can meet qualifications of different users. The experimental data show that the system can accomplish re-learning and expanding of welding process knowledge, and satisfy the command of the off-line programming system.

  1. A unified model of coupled arc plasma and weld pool for double electrodes TIG welding (United States)

    Wang, Xinxin; Fan, Ding; Huang, Jiankang; Huang, Yong


    A three-dimensional model containing tungsten electrodes, arc plasma and a weld pool is presented for double electrodes tungsten inert gas welding. The model is validated by available experimental data. The distributions of temperature, velocity and pressure of the coupled arc plasma are investigated. The current density, heat flux and shear stress over the weld pool are highlighted. The weld pool dynamic is described by taking into account buoyance, Lorentz force, surface tension and plasma drag force. The turbulent effect in the weld pool is also considered. It is found that the temperature and velocity distributions of the coupled arc are not rotationally symmetrical. A similar property is also shown by the arc pressure, current density and heat flux at the anode surface. The surface tension gradient is much larger than the plasma drag force and dominates the convective pattern in the weld pool, thus determining the weld penetration. The anodic heat flux and plasma drag force, as well as the surface tension gradient over the weld pool, determine the weld shape and size. In addition, provided the welding current through one electrode increases and that through the other decreases, keeping the total current unchanged, the coupled arc behaviour and weld pool dynamic change significantly, while the weld shape and size show little change. The results demonstrate the necessity of a unified model in the study of the arc plasma and weld pool.

  2. Automatic orbital GTAW welding: Highest quality welds for tomorrow's high-performance systems (United States)

    Henon, B. K.


    Automatic orbital gas tungsten arc welding (GTAW) or TIG welding is certain to play an increasingly prominent role in tomorrow's technology. The welds are of the highest quality and the repeatability of automatic weldings is vastly superior to that of manual welding. Since less heat is applied to the weld during automatic welding than manual welding, there is less change in the metallurgical properties of the parent material. The possibility of accurate control and the cleanliness of the automatic GTAW welding process make it highly suitable to the welding of the more exotic and expensive materials which are now widely used in the aerospace and hydrospace industries. Titanium, stainless steel, Inconel, and Incoloy, as well as, aluminum can all be welded to the highest quality specifications automatically. Automatic orbital GTAW equipment is available for the fusion butt welding of tube-to-tube, as well as, tube to autobuttweld fittings. The same equipment can also be used for the fusion butt welding of up to 6 inch pipe with a wall thickness of up to 0.154 inches.

  3. Laser welding of tailored blanks

    Directory of Open Access Journals (Sweden)

    Peças, P.


    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.

  4. Improving fatigue performance of rail thermite welds

    Directory of Open Access Journals (Sweden)

    Winiar L.


    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.

  5. 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)


    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.

  6. Research Activities at IPT, DTU on Resistance Projection Welding

    DEFF Research Database (Denmark)

    Bay, Niels


    Resistance welding processes and among these especially the resistance projection welding is considered an industrially strategic process with increasing applications as alternative to other welding processes, soldering, brazing and mechanical assembling. This is due to increasing requirements...

  7. The impact of welding wire on the mechanical properties of welded joints

    Directory of Open Access Journals (Sweden)

    Magdalena Mazur


    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

  8. Forming Completely Penetrated Welded T-joints when Pulsed Arc Welding (United States)

    Krampit, N. Yu; Krampit, M. A.; Sapozhkov, A. S.


    The paper is focused on revealing the influence of welding parameters on weld formation when pulsed arc welding. As an experimental sample a T-joint over 10 mm was selected. Welding was carried out in flat position, which required no edge preparation but provided mono-directional guaranteed root penetration. The following parameters of welding were subjected to investigation: gap in the joint, wire feed rate and incline angles of the torch along and across the weld axis. Technological recommendations have been made with respect to pulsed arc welding; the cost price of product manufacturing can be reduced on their basis due to reduction of labor input required by machining, lowering consumption of welding materials and electric power.

  9. Simplified welding distortion analysis for fillet welding using composite shell elements

    Directory of Open Access Journals (Sweden)

    Mingyu Kim


    Full Text Available This paper presents the simplified welding distortion analysis method to predict the welding deformation of both plate and stiffener in fillet welds. Currently, the methods based on equivalent thermal strain like Strain as Direct Boundary (SDB has been widely used due to effective prediction of welding deformation. Regarding the fillet welding, however, those methods cannot represent deformation of both members at once since the temperature degree of freedom is shared at the intersection nodes in both members. In this paper, we propose new approach to simulate deformation of both members. The method can simulate fillet weld deformations by employing composite shell element and using different thermal expansion coefficients according to thickness direction with fixed temperature at intersection nodes. For verification purpose, we compare of result from experiments, 3D thermo elastic plastic analysis, SDB method and proposed method. Compared of experiments results, the proposed method can effectively predict welding deformation for fillet welds.

  10. Effect of Pulse Parameters on Weld Quality in Pulsed Gas Metal Arc Welding: A Review (United States)

    Pal, Kamal; Pal, Surjya K.


    The weld quality comprises bead geometry and its microstructure, which influence the mechanical properties of the weld. The coarse-grained weld microstructure, higher heat-affected zone, and lower penetration together with higher reinforcement reduce the weld service life in continuous mode gas metal arc welding (GMAW). Pulsed GMAW (P-GMAW) is an alternative method providing a better way for overcoming these afore mentioned problems. It uses a higher peak current to allow one molten droplet per pulse, and a lower background current to maintain the arc stability. Current pulsing refines the grains in weld fusion zone with increasing depth of penetration due to arc oscillations. Optimum weld joint characteristics can be achieved by controlling the pulse parameters. The process is versatile and easily automated. This brief review illustrates the effect of pulse parameters on weld quality.

  11. Repair welding of cast iron coated electrodes (United States)

    Żuk, M.; Górka, J.; Dojka, R.; Czupryński, A.


    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.

  12. Risk Communication Concerning Welding Fumes for the Primary Preventive Care of Welding Apprentices in Southern Brazil


    Cezar-Vaz, Marta Regina; Bonow, Clarice Alves; Cezar Vaz, Joana


    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...

  13. Analysis of factors affecting fractures of rails welded by alumino-thermic welding

    Directory of Open Access Journals (Sweden)

    Sergejs MIKHAYLOVS


    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.

  14. Prediction of numerical distortion after welding with various welding sequences and clampings

    Directory of Open Access Journals (Sweden)

    S. Kastelic


    Full Text Available Welding simulation of a test cover for hydropower plant was made due to very large dimensions of the cover. The main aim was to predict distortion after welding in order to avoid machining the cover. Welding process was simulated with the Sysweld program to keep distortion in desired limits. Various welding sequences and clamping conditions were calculated to reduce the distortion. Calculation of microstructure constituents in virtual complex geometry of joints was also analyzed.

  15. Influence of the Initial Fiber Orientation on the Weld Strength in Welding of Glass Fiber Reinforced Thermoplastics

    Directory of Open Access Journals (Sweden)

    Isabel Fiebig


    Full Text Available The welding factors are significantly lower in welding of fiber reinforced thermoplastics than in welding of unreinforced thermoplastics due to the fiber orientation in the weld. This paper presents results from investigations on the influence of the initial fiber orientation on the weld strength in hot plate and vibration welding for glass fiber reinforced polypropylene and polyamide 6. Injection molded specimens are compared to specimens with main initial fiber orientation being longitudinal and transverse to the joining direction. The results of CT analysis of the fiber orientation in the weld show the opportunity to achieve a higher weld strength by using specimens with fibers being initially oriented longitudinally to the joining direction. The influence of the initial fiber orientation in the parts to be welded on the weld strength in hot plate welding is more distinct than in vibration welding.

  16. Welding and Joining of Titanium Aluminides (United States)

    Cao, Jian; Qi, Junlei; Song, Xiaoguo; Feng, Jicai


    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

  17. Laser Peening Effects on Friction Stir Welding (United States)

    Hatamleh, Omar


    Friction Stir Welding (FSW) is a welding technique that uses frictional heating combined with forging pressure to produce high strength bonds. It is attractive for aerospace applications. Although residual stresses in FSW are generally lower when compared to conventional fusion welds, recent work has shown that significant tensile residual stresses can be present in the weld after fabrication. Therefore, laser shock peening was investigated as a means of moderating the tensile residual stresses produced during welding. This slide presentation reviews the effect of Laser Peening on the weld, in tensile strength, strain, surface roughness, microhardness, surface wear/friction, and fatigue crack growth rates. The study concluded that the laser peening process can result in considerable improvement to crack initiaion, propagation and mechanical properties in FSW.

  18. Structural degradation of heterogeneous welded joints

    Directory of Open Access Journals (Sweden)

    Eva Schmidová


    Full Text Available 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 intercrystalline cracks form in the weld deposit layers. Structural analyses, chemical microanalyses and a hardness assessment were performed in order to identify the corresponding structural changes. The proportion of zonal vs. interdendritic segregation of the alloying elements in the degradation of the welded joint was distinguished. We described the nature of the structural heterogeneities produced, locally connected with the martensitic transformation. The chemical heterogeneity leading to the formation of martensite at grain boundaries was identified as the limiting effect.

  19. Femtosecond fiber laser welding of dissimilar metals. (United States)

    Huang, Huan; Yang, Lih-Mei; Bai, Shuang; Liu, Jian


    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.

  20. Welding and Joining of Titanium Aluminides. (United States)

    Cao, Jian; Qi, Junlei; Song, Xiaoguo; Feng, Jicai


    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.

  1. Welding and Joining of Titanium Aluminides

    Directory of Open Access Journals (Sweden)

    Jian Cao


    Full Text Available 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.

  2. Passively damped vibration welding system and method (United States)

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


    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.

  3. Friction Stir Welding of Steel Alloys (United States)

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


    The friction stir welding process has been developed primarily for the welding of aluminum alloys. Other higher melting allows such, as steels are much more difficult to join. Special attention must be given to pin tool material selection and welding techniques. This paper addresses the joining of steels and other high melting point materials using the friction stir welding process. Pin tool material and welding parameters will be presented. Mechanical properties of weldments will also be presented. Significance: There are many applications for the friction stir welding process other than low melting aluminum alloys. The FSW process can be expanded for use with high melting alloys in the pressure vessel, railroad and ship building industries.

  4. Control of welding distortion during gas metal arc welding of AH36 plates by stress engineering

    NARCIS (Netherlands)

    Pazooki, A.M.A.; Hermans, M.J.M.; Richardson, I.M.


    Welding residual stress and distortion are strongly linked together. One of the ways to control or reduce the welding distortions is the manipulation of the generated stresses during welding, and final residual stresses exist in the workpiece (stress engineering). In this paper, the control of gas

  5. Prediction of the weld pool geometry of TIG arc welding by using ...

    African Journals Online (AJOL)

    The present paper describes fuzzy logic simulation of tungsten inert gas welding (TIG) process to predict the weldment macrostructure zones' shape profile characteristics. The prediction of the weld pool geometry together with the shape of the heat affected zone (HAZ) was accomplished taking into account of TIG welding ...

  6. Numerical evaluation of multipass welding temperature field in API 5L X80 steel welded joints

    Directory of Open Access Journals (Sweden)

    J Nóbrega


    Full Text Available Many are the metallurgical changes suffered by materials when subjected to welding thermal cycle, promoting a considerable influence on the welded structures thermo mechanical properties. In project phase, one alternative for evaluating the welding cycle variable, would be the employment of computational methods through simulation. So, this paper presents an evaluation of the temperature field in a multipass welding of API 5L X80 steel used for oil and gas transportation, using the ABAQUS ® software, based on Finite Elements Method (FEM. During the simulation complex phenomena are considerable including: Variation in physical and mechanical properties of materials as a function of temperature, welding speed and the different mechanisms of heat exchange with the environment (convection and radiation were used. These considerations allow a more robust mathematical modeling for the welding process. An analytical heat source proposed by Goldak, to model the heat input in order to characterize the multipass welding through the GTAW (Gas Tungsten Arc Welding process on root and the SMAW (Shielded Metal Arc Welding process for the filling passes were used. So, it was possible to evaluate the effect of each welding pass on the welded joint temperature field, through the temperature peaks and cooling rates values during the welding process.

  7. Width Criterion For Weld-Seam-Tracking Data (United States)

    Lincir, Mark R.


    Image-processing algorithm in "through-torch-vision" (T3V) system developed to guide gas/tungsten arc welding robot along weld seam modified, according to proposal, reducing incidence of inaccurate tracking of weld seam. Developmental system intended to provide closed-loop control of motion of welding robot along weld seam on basis of lines in T3V image identified by use of image-processing algorithm and assumed to coincide with edges of weld seam. Use of width criterion prevents tracking of many false pairs of lines, with consequent decrease in incidence of inaccurate tracking and increase in confidence in weld-tracking capability of robotic welding system.

  8. A System for Complex Robotic Welding

    DEFF Research Database (Denmark)

    Madsen, Ole; Sørensen, Carsten Bro; Olsen, Birger


    This paper presents the architecture of a system for robotic welding of complex tasks. The system integrates off-line programming, control of redundant robots, collision-free motion planning and sensor-based control. An implementation for pipe structure welding made at Odense Steel Shipyard Ltd......., Denmark, demonstrates the system can be used for automatic welding of complex products in one-of-a-kind production....

  9. Numerical methods in simulation of resistance welding

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Martins, Paulo A.F.; Zhang, Wenqi


    Finite element simulation of resistance welding requires coupling betweenmechanical, thermal and electrical models. This paper presents the numerical models and theircouplings that are utilized in the computer program SORPAS. A mechanical model based onthe irreducible flow formulation is utilized...... a resistance welding point of view, the most essential coupling between the above mentioned models is the heat generation by electrical current due to Joule heating. The interaction between multiple objects is anothercritical feature of the numerical simulation of resistance welding because it influences...

  10. Heavy multi-pass TIG welding


    Maske, Tomas


    This study aims to find the maximum, usable, feed limit at different arc-energies and use the findings in multi-pass welding planning for robotic welding, taking into consideration the high controllability of robot movements. A combined studies using numerical analyses and practical experiments to calculate the feed limits for different arc energies. Each weld where analysed both mathematical, physical and thru observation. The combined results for one experiment will form the bases for th...

  11. Occupational rhinitis due to steel welding fumes. (United States)

    Castano, Roberto; Suarthana, Eva


    Exposure to welding fumes is a recognized respiratory hazard. Occupational asthma but not occupational rhinitis has been documented in workers exposed to steel welding fumes. We report a 26-year-old male with work-related rhinitis symptoms as well as lower airways symptoms suggestive of occupational asthma and metal fume fever associated with exposure to steel welding fumes. The diagnosis of occupational rhinitis was confirmed by specific inhalation challenge. © 2014 Wiley Periodicals, Inc.

  12. Effects Of Heat Sinks On VPPA Welds (United States)

    Nunes, Arthur C.; Steranka, Paul O., Jr.


    Report describes theoretical and experimental study of absorption of heat by metal blocks in contact with metal plate while plate subjected to variable-polarity plasma-arc (VPPA) welding. Purpose of study to contribute to development of comprehensive mathematical model of temperature in weld region. Also relevant to welding of thin sheets of metal to thick blocks of metal, heat treatment of metals, and hotspots in engines.

  13. Controlling Arc Length in Plasma Welding (United States)

    Iceland, W. F.


    Circuit maintains arc length on irregularly shaped workpieces. Length of plasma arc continuously adjusted by control circuit to maintain commanded value. After pilot arc is established, contactor closed and transfers arc to workpiece. Control circuit then half-wave rectifies ac arc voltage to produce dc control signal proportional to arc length. Circuit added to plasma arc welding machines with few wiring changes. Welds made with circuit cleaner and require less rework than welds made without it. Beads smooth and free of inclusions.

  14. Friction stir welding of single crystal aluminium

    DEFF Research Database (Denmark)

    Fonda, Richard Warren; Wert, John A.; Reynolds, A.P.


    Friction stir welds were prepared in different orientations in an aluminium single crystal. The welds were quenched to preserve the microstructure surrounding the tool and then electron backscattered diffraction was used to reveal the generation of grain boundaries and the evolution...... of crystallographic texture around the tool in each weld. The extent of both dynamic recrystallisation and conventional recrystallisation varied considerably as a function of weld orientation. As the base plate begins to interact with the deformation field surrounding the tool, regions of the single crystal rotate...

  15. Improving Fatigue Performance of AHSS Welds

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Zhili [ORNL; Yu, Xinghua [ORNL; ERDMAN III, DONALD L [ORNL; Wang, Yanli [ORNL; Kelly, Steve [ArcelorMittal USA; Hou, Wenkao [ArcelorMittal USA; Yan, Benda [ArcelorMittal USA; Wang, Zhifeng [Colorado School of Mines, Golden; Yu, Zhenzhen [Colorado School of Mines, Golden; Liu, Stephen [Colorado School of Mines, Golden


    Reported herein is technical progress on a U.S. Department of Energy CRADA project with industry cost-share aimed at developing the technical basis and demonstrate the viability of innovative in-situ weld residual stresses mitigation technology that can substantially improve the weld fatigue performance and durability of auto-body structures. The developed technology would be costeffective and practical in high-volume vehicle production environment. Enhancing weld fatigue performance would address a critical technology gap that impedes the widespread use of advanced high-strength steels (AHSS) and other lightweight materials for auto body structure light-weighting. This means that the automotive industry can take full advantage of the AHSS in strength, durability and crashworthiness without the concern of the relatively weak weld fatigue performance. The project comprises both technological innovations in weld residual stress mitigation and due-diligence residual stress measurement and fatigue performance evaluation. Two approaches were investigated. The first one was the use of low temperature phase transformation (LTPT) weld filler wire, and the second focused on novel thermo-mechanical stress management technique. Both technical approaches have resulted in considerable improvement in fatigue lives of welded joints made of high-strength steels. Synchrotron diffraction measurement confirmed the reduction of high tensile weld residual stresses by the two weld residual stress mitigation techniques.

  16. Friction Pull Plug Welding in Aluminum Alloys (United States)

    Brooke, Shane A.; Bradford, Vann


    NASA's Marshall Space Flight Center (MSFC) has recently invested much time and effort into the process development of Friction Pull Plug Welding (FPPW). FPPW, is a welding process similar to Friction Push Plug Welding in that, there is a small rotating part (plug) being spun and simultaneously pulled (forged) into a larger part. These two processes differ, in that push plug welding requires an internal reaction support, while pull plug welding reacts to the load externally. FPPW was originally conceived as a post proof repair technique for the Space Shuttle fs External Tank. FPPW was easily selected as the primary weld process used to close out the termination hole on the Constellation Program's ARES I Upper Stage circumferential Self-Reacting Friction Stir Welds (SR-FSW). The versatility of FPPW allows it to also be used as a repair technique for both SR-FSW and Conventional Friction Stir Welds. To date, all MSFC led development has been concentrated on aluminum alloys (2195, 2219, and 2014). Much work has been done to fully understand and characterize the process's limitations. A heavy emphasis has been spent on plug design, to match the various weldland thicknesses and alloy combinations. This presentation will summarize these development efforts including weld parameter development, process control, parameter sensitivity studies, plug repair techniques, material properties including tensile, fracture and failure analysis.

  17. Emissions of chromium (VI) from arc welding. (United States)

    Heung, William; Yun, Myoung-Jin; Chang, Daniel P Y; Green, Peter G; Halm, Chris


    The presence of Cr in the +6 oxidation state (Cr[VI]) is still observed in ambient air samples in California despite steps taken to reduce emissions from plating operations. One known source of emission of Cr(VI) is welding, especially with high Cr-content materials, such as stainless steels. An experimental effort was undertaken to expand and update Cr(VI) emission factors by conducting tests on four types of arc-welding operations: gas-metal arc welding (GMAW), shielded metal arc welding (SMAW), fluxcore arc welding, and pulsed GMAW. Standard American Welding Society hood results were compared with a total enclosure method that permitted isokinetic sampling for particle size-cut measurement, as well as total collection of the aerosol. The fraction of Cr(VI) emitted per unit mass of Cr electrode consumed was determined. Consistent with AP-42 data, initial results indicate that a significant fraction of the total Cr in the aerosol is in the +6 oxidation state. The fraction of Cr(VI) and total aerosol mass produced by the different arc welding methods varies with the type of welding process used. Self-shielded electrodes that do not use a shield gas, for example, SMAW, produce greater amounts of Cr(VI) per unit mass of electrode consumed. The formation of Cr(VI) from standard electrode wires used for welding mild steel was below the method detection limit after eliminating an artifact in the analytical method used.

  18. Melting Efficiency During Plasma Arc Welding (United States)

    McClure, J.C.; Evans, D. M.; Tang, W.; Nunes, A. C.


    A series of partial penetration Variable Polarity Plasma Arc welds were made at equal power but various combinations of current and voltage on 2219 aluminum. Arc Efficiency was measured calorimetrically and ranged between 48% and 66%. Melting efficiency depends on the weld pool shape. Increased current increases the melting efficiency as it increases the depth to width ratio of the weld pool. Higher currents are thought to raise arc pressure and depress the liquid at the bottom of the weld pool causing a more nearly two dimensional heat flow condition.

  19. Laser-TIG Welding of Titanium Alloys (United States)

    Turichin, G.; Tsibulsky, I.; Somonov, V.; Kuznetsov, M.; Akhmetov, A.


    The article presents the results of investigation the technological opportunity of laser-TIG welding of titanium alloys. The experimental stand for implementation of process with the capability to feed a filler wire was made. The research of the nature of transfer the filler wire into the welding pool has been demonstrated. The influence of distance between the electrode and the surface of the welded plates on the stability of the arc was shown. The relationship between welding velocity, the position of focal plane of the laser beam and the stability of penetration of plates was determined.

  20. Welding the AT-400A Containment Vessel

    Energy Technology Data Exchange (ETDEWEB)

    Brandon, E.


    Early in 1994, the Department of Energy assigned Sandia National Laboratories the responsibility for designing and providing the welding system for the girth weld for the AT-400A containment vessel. (The AT-400A container is employed for the shipment and long-term storage of the nuclear weapon pits being returned from the nation's nuclear arsenal.) Mason Hanger Corporation's Pantex Plant was chosen to be the production facility. The project was successfully completed by providing and implementing a turnkey welding system and qualified welding procedure at the Pantex Plant. The welding system was transferred to Pantex and a pilot lot of 20 AT-400A containers with W48 pits was welded in August 1997. This document is intended to bring together the AT-400A welding system and product (girth weld) requirements and the activities conducted to meet those requirements. This document alone is not a complete compilation of the welding development activities but is meant to be a summary to be used with the applicable references.

  1. Small Bore Piping Socket Weld Evaluation System

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Dong Min; Cho, Hong Seok; Choi, Sang Hoon; Cho, Ki Hyun; Lee, Jang Wook [Korea Plant Service and Enginccring Co., Seongnam (Korea, Republic of)


    Kori unit 3 had stopped operation due to leakage at Steam Generator drain line socket weld on June 6, 2008. The Cause of socket weld damage was known as a fatigue crack. According to this case, all socket welds located in RCS pressure boundary are carrying out Radiographic Testing. But to inspect socket welds by RT has some problems. The result of EPRI study showed that RT has limitation to find flaws at socket welds.The orientation of flaws has big influence on RT inspection capability and there is not enough space at socket welds for RT, dose problems as well. Although the gap between coupling and pipe at socket welds must follow up code, surface inspection can't inspect the gap. If there is absence of the gap, socket welds are damaged during operation. The gap should be identified by RT but the distance of gap can't be measured. As this paper, the ultrasonic inspection system was introduced to figure out indication and gap in the socket welds.

  2. Welding shield for coupling heaters (United States)

    Menotti, James Louis


    Systems for coupling end portions of two elongated heater portions and methods of using such systems to treat a subsurface formation are described herein. A system may include a holding system configured to hold end portions of the two elongated heater portions so that the end portions are abutted together or located near each other; a shield for enclosing the end portions, and one or more inert gas inlets configured to provide at least one inert gas to flush the system with inert gas during welding of the end portions. The shield may be configured to inhibit oxidation during welding that joins the end portions together. The shield may include a hinged door that, when closed, is configured to at least partially isolate the interior of the shield from the atmosphere. The hinged door, when open, is configured to allow access to the interior of the shield.

  3. Tailoring defect free fusion welds based on phenomenological modeling (United States)

    Kumar, Amit

    In the last few decades, phenomenological models of fusion welding have provided important understanding and information about the welding processes and welded materials. For example, numerical calculations of heat transfer and fluid flow in welding have enabled accurate quantitative calculations of thermal cycles and fusion zone geometry in fusion welding. In many simple systems such as gas tungsten arc (GTA) butt welding, the computed thermal cycles have been used to quantitatively understand weld metal phase compositions, grain sizes and inclusion structure. However, fabrication of defect free welds with prescribed attributes based on scientific principles still remains to be achieved. In addition, higher fabrication speeds are often limited by the occurrence of humping defects which are characterized by periodic bead-like appearance. Furthermore, phenomenological models have not been applied to tailor welds with given attributes. The goal of the present work is to apply the principles of heat transfer and fluid flow to attain defects free welds with prescribed attributes. Since there are a large number of process variables in welding, the desired weld attributes such as the weld geometry and structure are commonly produced by empirically adjusting the welding variables. However, this approach does not always produce optimum welds and inappropriate choice of variables can lead to poor welds. The existing transport phenomena based models of welding can only predict weld characteristics for a given set of input welding variables. What is needed, and not currently available, is a capability to systematically determine multiple paths to tailor weld geometry and assess robustness of each individual solution to achieve safe, defect free welds. Therefore, these heat transfer and fluid flow based models are restructured to predict the welding conditions to achieve the defect free welds with desired attributes. Systematic tailoring of weld attributes based on scientific

  4. Occupational urticaria from welding polyurethane

    Energy Technology Data Exchange (ETDEWEB)

    Kanerva, L.; Estlander, T.; Jolanki, R.; Laehteenmaeki, M.T.Ke.; Keskinen, H. (Institute of Occupational Health, Helsinki (Finland))


    An urticarial reaction associated with high fever developed in a welder on four occasions while he was welding steel profiles filled with polyurethane. The fumes emitted during pyrolysis of polyurethane and inhaled by the patient probably caused the urticarial reaction. Provocation tests with two pyrolysis products, 4,4-diphenylmethane diisocyanate and 4,4-diaminophenylmethane, were negative. This case demonstrates the difficulty in detecting the cause of urticaria induced by airborne chemicals.

  5. Quality status display for a vibration welding process (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


    A system includes a host machine and a status projector. The host machine is in electrical communication with a collection of sensors and with a welding controller that generates control signals for controlling the welding horn. The host machine is configured to execute a method to thereby process the sensory and control signals, as well as predict a quality status of a weld that is formed using the welding horn, including identifying any suspect welds. The host machine then activates the status projector to illuminate the suspect welds. This may occur directly on the welds using a laser projector, or on a surface of the work piece in proximity to the welds. The system and method may be used in the ultrasonic welding of battery tabs of a multi-cell battery pack in a particular embodiment. The welding horn and welding controller may also be part of the system.

  6. Weldability of AISI 304 to copper by friction welding

    Energy Technology Data Exchange (ETDEWEB)

    Kirik, Ihsan [Batman Univ. (Turkey); Balalan, Zulkuf [Firat Univ., Elazig (Turkey)


    Friction welding is a solid-state welding method, which can join different materials smoothly and is excessively used in manufacturing industry. Friction welding method is commonly used in welding applications of especially cylindrical components, pipes and materials with different properties, for which other welding methods remain incapable. AISI 304 stainless steel and a copper alloy of 99.6 % purity were used in this study. This couple was welded in the friction welding machine. After the welding process, samples were analyzed macroscopically and microscopically, and their microhardness was measured. Tensile test was used to determine the bond strength of materials that were joined using the friction welding method. At the end of the study, it was observed that AISI 304 stainless steel and copper could be welded smoothly using the friction welding method and the bond strength is close to the tensile strength of copper. (orig.)

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

    DEFF Research Database (Denmark)

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


    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...... norms. The paper describes the results obtained, showing significant productivity improvements and good weld qualities applying laser hybrid welding....

  8. Multi-mode ultrasonic welding control and optimization (United States)

    Tang, Jason C.H.; Cai, Wayne W


    A system and method for providing multi-mode control of an ultrasonic welding system. In one embodiment, the control modes include the energy of the weld, the time of the welding process and the compression displacement of the parts being welded during the welding process. The method includes providing thresholds for each of the modes, and terminating the welding process after the threshold for each mode has been reached, the threshold for more than one mode has been reached or the threshold for one of the modes has been reached. The welding control can be either open-loop or closed-loop, where the open-loop process provides the mode thresholds and once one or more of those thresholds is reached the welding process is terminated. The closed-loop control provides feedback of the weld energy and/or the compression displacement so that the weld power and/or weld pressure can be increased or decreased accordingly.

  9. Thermal insulation of wet shielded metal arc welds (United States)

    Keenan, Patrick J.


    Computational and experimental studies were performed to determine the effect of static thermal insulation on the quality of wet shielded metal arc welds (SMAW). A commercially available heat flow and fluid dynamics spectral-element computer program was used to model a wet SMAW and to determine the potential effect on the weld cooling rate of placing thermal insulation adjacent to the weld line. Experimental manual welds were made on a low carbon equivalent (0.285) mild steel and on a higher carbon equivalent (0.410) high tensile strength steel, using woven fabrics of alumina-boria-silica fibers to insulate the surface of the plate being welded. The effect of the insulation on weld quality was evaluated through the use of post-weld Rockwell Scale hardness measurements on the surface of the weld heat affected zones (HAZ's) and by visual inspection of sectioned welds at 10 X magnification. The computational simulation demonstrated a 150% increase in surface HAZ peak temperature and a significant decrease in weld cooling rate with respect to uninsulated welds, for welds in which ideal insulation had been placed on the base plate surface adjacent to the weld line. Experimental mild steel welds showed a reduction in surface HAZ hardness attributable to insulation at a 77% significance level. A visual comparison of the cross-sections of two welds made in 0.410 carbon equivalent steel-with approximately equivalent heat input-revealed underbead cracking in the uninsulated weld but not in the insulated weld.

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

    DEFF Research Database (Denmark)

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


    In this article, laboratory tests are demonstrated that systematically accesses the critical gap distance when welding CMn 2.13 mm steel with a 2.6 kW CO2 laser, combined with a MIG energy source. In the work, the welding speed is varied at gap distances from 0 to 0.8 mm such that the limits...... 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...

  11. Analysis of welding distortion due to narrow-gap welding of upper port plug

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Pankaj, E-mail: [Department of Ocean Engineering and Naval Architecture, Indian Institute of Technology, Kharagpur, Pin 721302 (India); Mandal, N.R., E-mail: nrm@naval.iitkgp.ernet.i [Department of Ocean Engineering and Naval Architecture, Indian Institute of Technology, Kharagpur, Pin 721302 (India); Vasu, Parameswaran, E-mail: parameswaran.vasu@iter-india.or [ITER-India, Institute of Plasma Research, Ahmedabad (India); Padasalag, Shrishail B., E-mail: subhasis.panja@iter-india.or [ITER-India, Institute of Plasma Research, Ahmedabad (India)


    Narrow-gap welding is a low distortion welding process. This process allows very thick plates to be joined using fewer weld passes as compared to conventional V-groove or double V-groove welding. In case of narrow-gap arc welding as the heat input and weld volume is low, it reduces thermal stress leading to reduction of both residual stress and distortion. In this present study the effect of narrow-gap welding was studied on fabrication of a scaled down port plug in the form of a trapezoidal box made of 10 mm thick mild steel (MS) plates using gas tungsten arc welding (GTAW). Inherent strain method was used for numerical prediction of resulting distortions. The numerical results compared well with that of the experimentally measured distortion. The validated numerical scheme was used for prediction of weld induced distortion due to narrow-gap welding of full scale upper port plug made of 60 mm thick SS316LN material as is proposed for use in ITER project. It was observed that it is feasible to fabricate the said port plug keeping the distortions minimum within about 7 mm using GTAW for root pass welding followed by SMAW for filler runs.

  12. Laser welding to expand the allowable gap in bore welding for ITER blanket hydraulic connection

    Energy Technology Data Exchange (ETDEWEB)

    Tanigawa, Hisashi, E-mail:; Maruyama, Takahito; Noguchi, Yuto; Takeda, Nobukazu; Kakudate, Satoshi


    For application to bore welding of hydraulic connection in the ITER blanket module, laser welding presents the following benefits: low weld heat input is preferred for re-welding of the irradiated material. Its contactless process can intrinsically avoid a failure mode of the tool sticking on the weld. The exact requirements for pipe alignment were assessed in comparison with the assembly tolerance. The groove geometry was modified to expand the allowable initial gap. The groove was machined to be partially thick to obviate the filler wire. First, plates with partially thick grooves were welded to elucidate the preferred groove geometry and welding conditions. With the modified groove, the plates were welded for the initial gap of 1.0 mm. Then the groove geometry and welding conditions were adjusted based on results of pipe welding tests. By application of the additional 0.5-mm-thick and 2.5-mm-wide metal in the groove, pipes with an initial gap of 0.7 mm were welded successfully.

  13. Analysis of the Corrosion Behavior of an A-TIG Welded SS 409 Weld Fusion Zone (United States)

    Vidyarthy, R. S.; Dwivedi, D. K.


    AISI 409 (SS 409) ferritic stainless steel is generally used as the thick gauge section in freight train wagons, in ocean containers, and in sugar refinery equipment. Activating the flux tungsten inert gas (A-TIG) welding process can reduce the welding cost during fabrication of thick sections. However, corrosion behavior of the A-TIG weld fusion zone is a prime concern for this type of steel. In the present work, the effect of the A-TIG welding process parameters on the corrosion behavior of a weld fusion zone made of 8-mm-thick AISI 409 ferritic stainless-steel plate has been analyzed. Potentiodynamic polarization tests were performed to evaluate the corrosion behavior. The maximum corrosion potential ( E corr) was shown by the weld made using a welding current of 215 A, a welding speed of 95 mm/min, and a flux coating density of 0.81 mg/cm2. The minimum E corr was observed in the weld made using a welding current of 190 A, a welding speed of 120 mm/min, and a flux coating density of 1.40 mg/cm2. The current study also presents the inclusive microstructure-corrosion property relationships using the collective techniques of scanning electron microscopy, energy-dispersive x-ray spectroscopy, and x-ray diffraction.

  14. Influence of the arc plasma parameters on the weld pool profile in TIG welding (United States)

    Toropchin, A.; Frolov, V.; Pipa, A. V.; Kozakov, R.; Uhrlandt, D.


    Magneto-hydrodynamic simulations of the arc and fluid simulations of the weld pool can be beneficial in the analysis and further development of arc welding processes and welding machines. However, the appropriate coupling of arc and weld pool simulations needs further improvement. The tungsten inert gas (TIG) welding process is investigated by simulations including the weld pool. Experiments with optical diagnostics are used for the validation. A coupled computational model of the arc and the weld pool is developed using the software ANSYS CFX. The weld pool model considers the forces acting on the motion of the melt inside and on the surface of the pool, such as Marangoni, drag, electromagnetic forces and buoyancy. The experimental work includes analysis of cross-sections of the workpieces, highspeed video images and spectroscopic measurements. Experiments and calculations have been performed for various currents, distances between electrode and workpiece and nozzle diameters. The studies show the significant impact of material properties like surface tension dependence on temperature as well as of the arc structure on the weld pool behaviour and finally the weld seam depth. The experimental weld pool profiles and plasma temperatures are in good agreement with computational results.

  15. Monitoring the quality of welding based on welding current and ste analysis (United States)

    Mazlan, Afidatusshimah; Daniyal, Hamdan; Izzani Mohamed, Amir; Ishak, Mahadzir; Hadi, Amran Abdul


    Qualities of welding play an important part in industry especially in manufacturing field. Post-welding non-destructive test is one of the importance process to ensure the quality of welding but it is time consuming and costly. To reduce the chance of defects, online monitoring had been utilized by continuously sense some of welding parameters and predict welding quality. One of the parameters is welding current, which is rich of information but lack of study focus on extract them at signal analysis level. This paper presents the analysis of welding current using Short Time Energy (STE) signal processing to quantify the pattern of the current. GMAW set with carbon steel specimens are used in this experimental study with high-bandwidth and high sampling rate oscilloscope capturing the welding current. The results indicate welding current as signatures have high correlation with the welding process. Continue with STE analysis, the value below 5000 is declare as good welding, meanwhile the STE value more than 6000 is contained defect.

  16. Probing weld quality monitoring in friction stir welding through characterization of signals by fractal theory

    Energy Technology Data Exchange (ETDEWEB)

    Das, Bipul; Bag, Swarup; Pal, Sukhomay [Indian Institute of Technology Guwahati, Assam (India)


    Providing solutions towards the improvisation of welding technologies is the recent trend in the Friction stir welding (FSW) process. We present a monitoring approach for ultimate tensile strength of the friction stir welded joints based on information extracted from process signals through implementing fractal theory. Higuchi and Katz algorithms were executed on current and tool rotational speed signals acquired during friction stir welding to estimate fractal dimensions. Estimated fractal dimensions when correlated with the ultimate tensile strength of the joints deliver an increasing trend with the increase in joint strength. It is observed that dynamicity of the system strengthens the weld joint, i.e., the greater the fractal dimension, the better will be the quality of the weld. Characterization of signals by fractal theory indicates that the single-valued indicator can be an alternative for effective monitoring of the friction stir welding process.

  17. The optimization of welding regime parameters at shielded metal arc welding (SMAW by mathematical modeling

    Directory of Open Access Journals (Sweden)

    V. Petrescu


    Full Text Available The realized researches followed the determining of mathematical models that allow the optimization of the welding process in order to obtain welded joints with certain values of the mechanical characteristics. Thus, there were established mathematical models of dependence of mechanical characteristics of welded joints (Rm, Rp02, Z, A, KCV 20°C of each parameter of welding regime (Iw, Uw, and also, mathematical models that offer cumulative dependence of mechanical characteristics of both parameters of welding regime.The researches have been carried out using steel E 36-4 as base material and as filler material basic electrodes, type E7018 and the applied welding procedure was the process: shielded metal arc welding (SMAW.

  18. Models for selecting GMA Welding Parameters for Improving Mechanical Properties of Weld Joints (United States)

    Srinivasa Rao, P.; Ramachandran, Pragash; Jebaraj, S.


    During the process of Gas Metal Arc (GMAW) welding, the weld joints mechanical properties are influenced by the welding parameters such as welding current and arc voltage. These parameters directly will influence the quality of the weld in terms of mechanical properties. Even small variation in any of the cited parameters may have an important effect on depth of penetration and on joint strength. In this study, S45C Constructional Steel is taken as the base metal to be tested using the parameters wire feed rate, voltage and type of shielding gas. Physical properties considered in the present study are tensile strength and hardness. The testing of weld specimen is carried out as per ASTM Standards. Mathematical models to predict the tensile strength and depth of penetration of weld joint have been developed by regression analysis using the experimental results.

  19. Mechanical Characteristics of Welded Joints of Aluminum Alloy 6061 T6 Formed by Arc and Friction Stir Welding (United States)

    Astarita, A.; Squillace, A.; Nele, L.


    Butt welds formed by arc welding in inert gas with nonconsumable electrode (tungsten inert gas (TIG) welding) and by friction stir welding (FSW) from aluminum alloy AA6061 T6 are studied. Comparative analysis of the structures and mechanical properties of the welded joints is performed using the results of optical and electron microscopy, tensile tests, tests for residual bending ductility, and measurements of microhardness. The changes in the microstructure in different zones and the degrees of degradation of the mechanical properties after the welding are determined. It is shown that the size of the tool for the friction stir welding affects the properties of the welds. Quantitative results showing the relation between the microscopic behavior of the alloy and the welding-induced changes in the microstructure are obtained. Friction stir welding is shown to provide higher properties of the welds.

  20. Gimbaled-shoulder friction stir welding tool (United States)

    Carter, Robert W. (Inventor); Lawless, Kirby G. (Inventor)


    A gimbaled-shoulder friction stir welding tool includes a pin and first and second annular shoulders coupled to the pin. At least one of the annular shoulders is coupled to the pin for gimbaled motion with respect thereto as the tool is rotated by a friction stir welding apparatus.

  1. Potential Benefits of Ultrasonically Assisted Fusion Welding ...

    African Journals Online (AJOL)

    Many of the processes in which ultrasonic oscillations have been beneficial are similar to fusion welding process where the quality of welds depends on porosity, crystallisation rate, inclusions, inter-metallic compounds, depth of penetration, heat affected zone, etc. Some preliminary tests were performed to assess the effects ...

  2. The Influence of Friction Stir Weld Tool Form and Welding Parameters on Weld Structure and Properties: Nugget Bulge in Self-Reacting Friction Stir Welds (United States)

    Schneider, Judy; Nunes, Arthur C., Jr.; Brendel, Michael S.


    Although friction stir welding (FSW) was patented in 1991, process development has been based upon trial and error and the literature still exhibits little understanding of the mechanisms determining weld structure and properties. New concepts emerging from a better understanding of these mechanisms enhance the ability of FSW engineers to think about the FSW process in new ways, inevitably leading to advances in the technology. A kinematic approach in which the FSW flow process is decomposed into several simple flow components has been found to explain the basic structural features of FSW welds and to relate them to tool geometry and process parameters. Using this modelling approach, this study reports on a correlation between the features of the weld nugget, process parameters, weld tool geometry, and weld strength. This correlation presents a way to select process parameters for a given tool geometry so as to optimize weld strength. It also provides clues that may ultimately explain why the weld strength varies within the sample population.

  3. 49 CFR 192.225 - Welding procedures. (United States)


    ... qualified under section 5 of API 1104 (incorporated by reference, see § 192.7) or section IX of the ASME Boiler and Pressure Vessel Code “ Welding and Brazing Qualifications” (incorporated by reference, see... 49 Transportation 3 2010-10-01 2010-10-01 false Welding procedures. 192.225 Section 192.225...

  4. Welding/brazing for Space Station repair (United States)

    Dickinson, David W.; Babel, H. W.; Conaway, H. R.; Hooper, W. H.


    Viewgraphs on welding/brazing for space station repair are presented. Topics covered include: fabrication and repair candidates; debris penetration of module panel; welded repair patch; mechanical assembly of utility fluid line; space station utility systems; Soviet aerospace fabrication - an overview; and processes under consideration.

  5. Improved electron-beam welding technique (United States)

    Schumacher, B.


    Electron-beam generator produces high quality welds without vaporization by relying on the mobility and hydrodynamic properties of the material in its liquid phase. The power density of the beam is relative to the speed of the workpiece, producing an inclined weld-front.

  6. Onorbit electron beam welding experiment definition (United States)


    The proposed experiment design calls for six panels to be welded, each having unique characteristics selected to yield specific results and information. The experiment is completely automated and the concept necessitated the design of a new, miniaturized, self-contained electron beam (EB) welding system, for which purpose a separate IR and D was funded by the contractor, Martin Marietta Corporation. Since future tasks beyond the proposed experiment might call for astronauts to perform hand-held EB gun repairs or for the gun to be interfaced with a dexterous robot such as the planned flight telerobotic servicer (FTS), the EB gun is designed to be dismountable from the automated system. In the experiment design, two separate, identical sets of weld panels will be welded, one on earth in a vacuum chamber and the other onorbit in the aft cargo bay of an orbiter. Since the main objective of the experiment is to demonstrate that high quality welds can be achieved under onorbit conditions, the welds produced will be subjected to a wide range of discriminating non-destructive Q.C. procedures and destructive physical tests. However, advantage will be taken of the availability of a fairly large quantity of welded material in the two series of welded specimens to widen the circle of investigative talent by providing material to academic and scientific institutions for examination.

  7. Robotic Variable Polarity Plasma Arc (VPPA) Welding (United States)

    Jaffery, Waris S.


    The need for automated plasma welding was identified in the early stages of the Space Station Freedom Program (SSFP) because it requires approximately 1.3 miles of welding for assembly. As a result of the Variable Polarity Plasma Arc Welding (VPPAW) process's ability to make virtually defect-free welds in aluminum, it was chosen to fulfill the welding needs. Space Station Freedom will be constructed of 2219 aluminum utilizing the computer controlled VPPAW process. The 'Node Radial Docking Port', with it's saddle shaped weld path, has a constantly changing surface angle over 360 deg of the 282 inch weld. The automated robotic VPPAW process requires eight-axes of motion (six-axes of robot and two-axes of positioner movement). The robot control system is programmed to maintain Torch Center Point (TCP) orientation perpendicular to the part while the part positioner is tilted and rotated to maintain the vertical up orientation as required by the VPPAW process. The combined speed of the robot and the positioner are integrated to maintain a constant speed between the part and the torch. A laser-based vision sensor system has also been integrated to track the seam and map the surface of the profile during welding.

  8. Fatigue Behavior of Inconel 718 TIG Welds (United States)

    Alexopoulos, Nikolaos D.; Argyriou, Nikolaos; Stergiou, Vasillis; Kourkoulis, Stavros K.


    Mechanical behavior of reference and TIG-welded Inconel 718 specimens was examined in the present work. Tensile, constant amplitude fatigue, and fracture toughness tests were performed in ambient temperature for both, reference and welded specimens. Microstructure revealed the presence of coarse and fine-grained heat-affected zones. It has been shown that without any post-weld heat treatment, welded specimens maintained their tensile strength properties while their ductility decreased by more than 40%. It was found that the welded specimens had lower fatigue life and this decrease was a function of the applied fatigue maximum stress. A 30% fatigue life decrease was noticed in the high cycle fatigue regime for the welded specimens while this decrease exceeded 50% in the low cycle fatigue regime. Cyclic stress-strain curves showed that Inconel 718 experiences a short period of hardening followed by softening for all fatigue lives. Cyclic fatigue response of welded specimens' exhibited cyclically stable behavior. Finally, a marginal decrease was noticed in the Mode I fracture toughness of the welded specimens.

  9. Welding of a metal-polymer laminate

    NARCIS (Netherlands)

    Gower, H.L.


    The purpose of this work is to investigate the weldability of a metal polymer sandwich structure. The welding of the sandwich material proceeds first by welding of the skin layer. The material selected for this research is Steelite, a sandwich structure developed by Corus, with 0.12 mm thick mild

  10. Signal Analysis of Gas Tungsten Arc Welds (United States)

    Eagar, T. W.


    Gas tungsten arc welding is a process in which the input parameters such as current, voltage and travel speed, can be easily controlled and/or monitored. However, weld quality is not solely a function of these parameters. An adaptive method of observing weld quality is desired to improve weld quality assurance. The use of dynamic electrical properties of the welding arc as a weld quality monitor was studied. The electrical properties of the arc are characterized by the current voltage transfer function. The hardware and software necessary to collect the data at a maximum rate of 45 kHz and to allow the off-line processing of this data are tested. The optimum input current waveform is determined. Bead-on-plate welds to observe such characteristics of the weld as the fundamental frequency of the puddle are studied. Future work is planned to observe changes of the arc response with changes in joint geometry, base metal chemistry, and shielding gas composition are discussed.


    Energy Technology Data Exchange (ETDEWEB)

    Daugherty, W.; Howard, S.; Peterson, K.; Stokes, M.


    Excess plutonium materials in the DOE complex are packaged and stored in accordance with DOE-STD-3013. This standard specifies requirements for the stabilization of such materials and subsequent packaging in dual nested seal-welded containers. Austenitic stainless steels have been selected for container fabrication. The inner 3013 container provides contamination control while the outer 3013 container is the primary containment vessel and is the focus of this paper. Each packaging site chose a process for seal welding the outer 3013 containers in accordance with its needs and expertise. The two processes chosen for weld closure were laser beam welding (LBW) and gas tungsten arc welding (GTAW). Following development efforts, each system was qualified in accordance with DOE-STD-3013 prior to production use. The 3013 outer container closure weld joint was designed to accommodate the characteristics of a laser weld. This aspect of the joint design necessitated some innovative process and equipment considerations in the application of the GTAW process. Details of the weld requirements and the development processes are presented and several potential enhancements for the GTAW system are described.


    African Journals Online (AJOL)


    Aug 2, 2013 ... ABSTRACT: An analysis was carried out to determine the strength of welded joints in. High Density Polyethylene (HDPE) dam liners. Samples were collected of welded joints and subjected to tensile tests and creep test. It was observed that the welded joints from field welded samples were much weaker ...

  13. Student Material for Competency-Based Education Curriculum for Welding. (United States)

    Associated Educational Consultants, Inc., Pittsburgh, PA.

    This student welding competency-based education curriculum consists of six units dealing with general areas related to trade occupations and nine units covering specific aspects of working with welding equipment and performing welding operations. Topics covered in the first six units are welding opportunities, human relations, safety, basic…


    African Journals Online (AJOL)

    Effect of post- weld heat treatment on the microstructure and mechanical properties of arc welded medium carbon steel was investigated. Medium carbon steel samples were butt- welded by using the shielded metal arc welding technique and, thereafter, heat treated by annealing, normalising and quench hardening in ...

  15. Investigation on various welding consumables on properties of ...

    Indian Academy of Sciences (India)

    Pritesh Prajapati


    Aug 28, 2017 ... Abstract. In this present work, the influence of different consumables on weld properties of carbon steel plate was studied by automatic gas metal arc welding under constant voltage mode. For all experiments, the process parameters such as welding current of 200 A, voltage of 28 V and welding speed of ...

  16. 30 CFR 57.14213 - Ventilation and shielding for welding. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Ventilation and shielding for welding. 57.14213... welding. (a) Welding operations shall be shielded when performed at locations where arc flash could be hazardous to persons. (b) All welding operations shall be well-ventilated. ...

  17. Experimental study of mechanical properties of friction welded AISI ...

    Indian Academy of Sciences (India)

    Friction welding is widely used as a mass production method in various industries. In the present study, an experimental set-up was designed in order to achieve friction welding of plastically deformed AISI 1021 steels. In this study, low alloy steel (AISI 1021) was welded under different welding parameters and afterwards ...

  18. Experimental study of mechanical properties of friction welded AISI ...

    Indian Academy of Sciences (India)

    Abstract. Friction welding is widely used as a mass production method in vari- ous industries. In the present study, an experimental set-up was designed in order to achieve friction welding of plastically deformed AISI 1021 steels. In this study, low alloy steel (AISI 1021) was welded under different welding parameters and ...


    Directory of Open Access Journals (Sweden)

    Gheorghe AMZA


    Full Text Available This paper presents a series of investigations undertaken to establish the impact of gas welding results in fusion welding procedures and welders health operators who work in departments making welded construction. Are the main gases that occur in fusion welding and main effects of short-term and long on the human body.

  20. Microgalvanic corrosion of laser-welded HSLA steels

    NARCIS (Netherlands)

    De Wit, J.H.; Looi, Y.M.

    Laser welding of galvanized high strength low alloy (HSLA) steels leads to the evaporation of zinc at the weld and the formation of a heat-affected-zone (HAZ). High heat input due to welding generates macro galvanic coupling between the weld and the parent metal as well as micro galvanic corrosion

  1. What makes an electric welding arc perform its required function

    Energy Technology Data Exchange (ETDEWEB)

    Correy, T.B.


    The physics of direct current and alternating current welding arcs, the heat transfer of direct current welding arcs, the characteristics of dc welding and ac welding power supplies and recommendations for the procurement and maintenance of precision power supplies are discussed. (LCL)

  2. Microgalvanic corrosion of laser-welded HSLA steels

    NARCIS (Netherlands)

    Looi, Y.M.


    Laser welding of galvanized high strength low alloy (HSLA) steels leads to the evaporation of zinc at the weld and the formation of a heat-affected-zone (HAZ). High heat input due to welding generates macro galvanic coupling between the weld and the parent metal as well as micro galvanic corrosion

  3. Identification of Mechanical parameters for Resistance Welding Machines

    DEFF Research Database (Denmark)

    Wu, Pei; Zhang, Wenqi; Bay, Niels


    Mechanical dynamic responses of resistance welding machine have a significant influence on weld quality and electrode service life, it must be considered when the real welding production is carried out or the welding process is simulated. The mathematical models for characterizing the mechanical ...

  4. Technical specifications on the welding in fuel reprocessing plants

    Energy Technology Data Exchange (ETDEWEB)

    Karino, Motonobu; Uryu, Mitsuru; Matsui, N.; Nakazawa, Fumio; Imanishi, Makoto; Koizumi; Kazuhiko; Sugawara, Junichi; Tanaka, Hideo


    The past specifications SGN of the welding in JNC was reexamined for the reprocessing plants in order to further promote the quality control. The specification first concerns the quality of raw materials, items of the quality tests, material management, and qualification standards of the welders. It extends over details of the welding techniques, welding design, welding testings, inspection and the judgment standards. (H. Baba)

  5. Testing and Modeling of Mechanical Characteristics of Resistance Welding Machines

    DEFF Research Database (Denmark)

    Wu, Pei; Zhang, Wenqi; Bay, Niels


    The dynamic mechanical response of resistance welding machine is very important to the weld quality in resistance welding especially in projection welding when collapse or deformation of work piece occurs. It is mainly governed by the mechanical parameters of machine. In this paper, a mathematical...

  6. 29 CFR 1910.254 - Arc welding and cutting. (United States)


    ... 29 Labor 5 2010-07-01 2010-07-01 false Arc welding and cutting. 1910.254 Section 1910.254 Labor... OCCUPATIONAL SAFETY AND HEALTH STANDARDS Welding, Cutting and Brazing § 1910.254 Arc welding and cutting. (a... following limits shall not be exceeded: (i) Alternating-current machines (A) Manual arc welding and cutting...

  7. Thermomechanical Modelling of Friction Stir Welding

    DEFF Research Database (Denmark)

    Hattel, Jesper Henri; Schmidt, Henrik Nikolaj Blicher; Tutum, Cem Celal


    Friction Stir Welding (FSW) is a fully coupled thermomechanical process and should in general be modelled as such. Basically, there are two major application areas of thermomechanical models in the investigation of the FSW process: i) Analysis of the thermomechanical conditions such as e.g. heat...... generation and local material deformation (often referred to as flow) during the welding process itself. ii) Prediction of the residual stresses that will be present in the joint structure post to welding. While the former in general will call for a fully-coupled thermomechanical procedure, however...... for the FSW process at hand, the heat generation must either be prescribed analytically or based on a fully coupled analysis of the welding process itself. Along this line, a recently proposed thermal-pseudo-mechanical model is presented in which the temperature dependent yield stress of the weld material...

  8. Passive Visual Sensing in Automatic Arc Welding

    DEFF Research Database (Denmark)

    Liu, Jinchao

    For decades much work has been devoted to the research and development of automatic arc welding systems. However, it has remained a challenging problem. Besides the very complex arc welding process itself, the lack of ability to precisely sense the welding process, including the seam geometry...... and the weld pool, has also prevented the realization of a closed-loop control system for many years, even though a variety of sensors have been developed. Among all the sensor systems, visual sensors have the advantage of receiving visual information and have been drawn more and more attentions. Typical...... industrial solutions for seam detection such as using laser scanners suer from several limitations. For instance, it must be positioned some distance ahead to the molten pool and may cause problem when dealing with shiny surfaces. Existing techniques for weld pool sensing mostly rely on auxiliary light...


    Directory of Open Access Journals (Sweden)

    Eva Schmidová


    Full Text Available 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 analysis of heterogeneous weld joints 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 fusion line and the circumstances under which intercrystalline cracks form in the weld deposit layers. Structural analyses, chemical microanalyses and a hardness assessment were performed in order to identify the corresponding structural changes. The proportion of zonal vs. interdendritic segregation of the alloying elements in the degradation of the welded joint was distinguished. We described the nature of the structural heterogeneities produced, locally connected with the martensitic transformation. The chemical heterogeneity leading to the formation of martensite at grain boundaries was identified as the limiting effect.

  10. Friction Stir Welding of Magnesium Die Castings (United States)

    Skar, Jan Ivar; Gjestland, Haavard; Oosterkamp, Ljiljana Djapic; Albright, Darryl L.

    Friction stir welding (FSW), being a solid-state process, is an attractive method for joining magnesium die castings. In this study, FSW of AZ91D and AM50A plates was performed both on the individual alloys and to join them together. The welds were sound and free from defects, except for small surface cracks in AM50A; a fine microstructure characterized the weld zones. The tensile properties of specimens transverse to the weld zone were measured, as were the corrosion properties. The tensile properties were somewhat lower than the base metal, with the largest percentage decrease found in the elongation of AM50A, perhaps due to the surface cracking. The corrosion resistance of the weld zone was relatively poor, most likely due to iron contamination from wearing of the tool. Further optimization of the FSW tool design and process parameters must take place to improve the reliability of FSW for magnesium die castings.

  11. Fine particles in welding workshop; Hitsaamon pienhiukkaset

    Energy Technology Data Exchange (ETDEWEB)

    Haenninen, H.; Koskinen, A. [Helsinki Unviv. of Technology, Materials Sciences and Engineering, Espoo (Finland)


    The objectives of the project were to research ultra- fine particles developed in the welding and cutting processes, to classify the particles in the welding fume, as well as to assess how they transform in air and drift in the internal air. Also it was attempted to decrease the amount of ultra-fine particles in the welding processes and in the internal air. Experiments were performed in the laboratory environments so that the results are valid and comparable. The fine particles in the fumes were measured and sampled by cascade impactors (ELPI, DLPI), by SMPS and by filter samplers (personal and area). The composition, size, shape and activity of the particles were determined. During the project efficiency of personal welding helmets, fume extraction welding guns and MFI-precipitator were tested. Tests were carried out in the laboratory and in the industrial workshops. The three-year project started in the beginning of February 2003. (orig.)

  12. Ductility of stabilized ferritic stainless steel welds (United States)

    Hunter, G. B.; Eagar, T. W.


    An investigation was made into the mechanism of ductility loss in low interstitial 18 Cr-2Mo ferritic stainless steel welds stabilized with Ti and Nb. It was found that stabilizing TiN or Nb(C,N) precipitates are dissolved during the welding process, resulting in a finer distribution of precipitates in the weld metal than in the base metal. Furthermore, the FATT was found to increase by more than 200°C, leading to decreased room temperature ductility. Such an increase in FATT may not be explained solely in terms of grain growth. Internal friction measurements indicate that no free nitrogen is present in the weld metal, yet wet chemical analysis reveals that the nitrogen is present in a soluble form. Kinetic arguments suggest that the stabilized nitrogen dissolved during welding tends to reprecipitate during solidification in the form of a chromium rich nitride phase.

  13. Fine tuning of dwelling time in friction stir welding for preventing material overheating, weld tensile strength increase and weld nugget size decrease

    Directory of Open Access Journals (Sweden)

    Mijajlović Miroslav M.


    Full Text Available After successful welding, destructive testing into test samples from Al 2024-T351 friction stir butt welds showed that tensile strength of the weld improve along the joint line, while dimensions of the weld nugget decrease. For those welds, both the base material and the welding tool constantly cool down during the welding phase. Obviously, the base material became overheated during the long dwelling phase what made conditions for creation of joints with the reduced mechanical properties. Preserving all process parameters but varying the dwelling time from 5-27 seconds a new set of welding is done to reach maximal achievable tensile strength. An analytical-numerical-experimental model is used for optimising the duration of the dwelling time while searching for the maximal tensile strength of the welds

  14. Effect of heat input on dilution and heat affected zone in submerged ...

    Indian Academy of Sciences (India)

    Submerged arc welding (SAW) is a fusion joining process, known for its high deposition capabilities. This process is useful in joining thick section components used in various industries. Besides joining, SAW can also be used for surfacing applications. Heat Affected Zone (HAZ) produced within the base metal as a result of ...

  15. Effect of heat input on dilution and heat affected zone in submerged ...

    Indian Academy of Sciences (India)

    Effect of heat input on dilution and heat affected zone in submerged arc welding process. HARI OM1,∗ and SUNIL PANDEY2. 1Department of Mechanical Engineering, YMCA University of Science and. Technology, Sector 06, Faridabad 121 006, India. 2Department of Mechanical Engineering, Indian Institute of Technology ...

  16. Analysis of the quality renovated continuous steel casting roller

    Indian Academy of Sciences (India)

    Renovation of continuous steel casting rollers, made of X12Cr13 EN 10088-1-97, was realised using submerged arc surfacing technology. ... were made in the influence of surfacing parameters on cladding metal mixing (mixed) with base metal and also influence of heat introduced by welding using metallographic analysis.

  17. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Home; Journals; Sadhana. PRASENJIT DEY. Articles written in Sadhana. Volume 41 Issue 5 May 2016 pp 549-559. A comparative study of multiple regression analysis and back propagation neural network approaches on plain carbon steel in submerged-arc welding · ABHIJIT SARKAR PRASENJIT DEY R N RAI SUBHAS ...

  18. Microstructure and Mechanical Properties of an Ultrasonic Spot Welded Aluminum Alloy: The Effect of Welding Energy (United States)

    Peng, He; Chen, Daolun; Jiang, Xianquan


    The aim of this study is to evaluate the microstructures, tensile lap shear strength, and fatigue resistance of 6022-T43 aluminum alloy joints welded via a solid-state welding technique–ultrasonic spot welding (USW)–at different energy levels. An ultra-fine necklace-like equiaxed grain structure is observed along the weld line due to the occurrence of dynamic crystallization, with smaller grain sizes at lower levels of welding energy. The tensile lap shear strength, failure energy, and critical stress intensity of the welded joints first increase, reach their maximum values, and then decrease with increasing welding energy. The tensile lap shear failure mode changes from interfacial fracture at lower energy levels, to nugget pull-out at intermediate optimal energy levels, and to transverse through-thickness (TTT) crack growth at higher energy levels. The fatigue life is longer for the joints welded at an energy of 1400 J than 2000 J at higher cyclic loading levels. The fatigue failure mode changes from nugget pull-out to TTT crack growth with decreasing cyclic loading for the joints welded at 1400 J, while TTT crack growth mode remains at all cyclic loading levels for the joints welded at 2000 J. Fatigue crack basically initiates from the nugget edge, and propagates with “river-flow” patterns and characteristic fatigue striations. PMID:28772809

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

    Directory of Open Access Journals (Sweden)

    Koray Yurtisik


    Full Text Available Despite its high efficiency, autogenous keyhole welding is not well-accepted for duplex stainless steels because it causes excessive ferrite in as-welded duplex microstructure, which leads to a degradation in toughness and corrosion properties of the material. Combining the deep penetration characteristics of plasma arc welding in keyhole mode and metal deposition capability of gas metal arc welding, hybrid plasma - gas metal arc welding process has considered for providing a proper duplex microstructure without compromising the welding efficiency. 11.1 mm-thick standard duplex stainless steel plates were joined in a single-pass using this novel technique. Same plates were also subjected to conventional gas metal arc and plasma arc welding processes, providing benchmarks for the investigation of the weldability of the material. In the first place, the hybrid welding process enabled us to achieve less heat input compared to gas metal arc welding. Consequently, the precipitation of secondary phases, which are known to be detrimental to the toughness and corrosion resistance of duplex stainless steels, was significantly suppressed in both fusion and heat affected zones. Secondly, contrary to other keyhole techniques, proper cooling time and weld metal chemistry were achieved during the process, facilitating sufficient reconstructive transformation of austenite in the ferrite phase.

  20. Effects of Flux Precoating and Process Parameter on Welding Performance of Inconel 718 Alloy TIG Welds (United States)

    Lin, Hsuan-Liang; Wu, Tong-Min; Cheng, Ching-Min


    The purpose of this study is to investigate the effect of activating flux on the depth-to-width ratio (DWR) and hot cracking susceptibility of Inconel 718 alloy tungsten inert gas (TIG) welds. The Taguchi method is employed to investigate the welding parameters that affect the DWR of weld bead and to achieve optimal conditions in the TIG welds that are coated with activating flux in TIG (A-TIG) process. There are eight single-component fluxes used in the initial experiment to evaluate the penetration capability of A-TIG welds. The experimental results show that the Inconel 718 alloy welds precoated with 50% SiO2 and 50% MoO3 flux were provided with better welding performance such as DWR and hot cracking susceptibility. The experimental procedure of TIG welding process using mixed-component flux and optimal conditions not only produces a significant increase in DWR of weld bead, but also decreases the hot cracking susceptibility of Inconel 718 alloy welds.

  1. Effect of post weld impact treatment (PWIT) on mechanical properties of spot-welded joint (United States)

    Ghazali, F. A.; Salleh, Z.; Hyie, K. M.; Rozlin, N. M. Nik; Hamidi, S. H. Ahmad; Padzi, M. M.


    This paper focuses on the study of improvement for spot welding on the tensile shear and hardness by applying post weld impact treatment (PWIT) on the welded joint. The main objective of the research is to characterize and improve the mechanical properties of the joint. The method of PWIT used on the welded joint was Pneumatic Impact Treatment (PIT). The concept of PIT on spot welding is that it improves the mechanical properties of the welded zone. The working sample was undergoing a resistance spot welding of joining two similar in dimension and material of a steel plate before treated. The dimension of both plate are 110 mm × 45 mm × 1.2 mm and the material used were low carbon steel (LCS). All the welded samples were tested for its mechanical properties by performing the tensile-shear and hardness test. Tensile-shear test was conducted on the spot welded, both treated and as-welded samples using crosshead speed of 2 mm/min, while hardness test was performed using 1kgf load via Vickers hardness indenter. The effects of PIT on tensile-shear properties and hardness were evaluated and found that the implementation of PIT has increased tensile shear and hardness significantly.

  2. Virtual Welded - Joint Design Integrating Advanced Materials and Processing Technology

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhishang; Ludewig, Howard W.; Babu, S. Suresh


    Virtual Welede-Joint Design, a systematic modeling approach, has been developed in this project to predict the relationship of welding process, microstructure, properties, residual stress, and the ultimate weld fatique strength. This systematic modeling approach was applied in the welding of high strength steel. A special welding wire was developed in this project to introduce compressive residual stress at weld toe. The results from both modeling and experiments demonstrated that more than 10x fatique life improvement can be acheived in high strength steel welds by the combination of compressive residual stress from the special welding wire and the desired weld bead shape from a unique welding process. The results indicate a technology breakthrough in the design of lightweight and high fatique performance welded structures using high strength steels.

  3. Performance Improvement of Friction Stir Welds by Better Surface Finish (United States)

    Russell, Sam; Nettles, Mindy


    The as-welded friction stir weld has a cross section that may act as a stress concentrator. The geometry associated with the stress concentration may reduce the weld strength and it makes the weld challenging to inspect with ultrasound. In some cases, the geometry leads to false positive nondestructive evaluation (NDE) indications and, in many cases, it requires manual blending to facilitate the inspection. This study will measure the stress concentration effect and develop an improved phased array ultrasound testing (PAUT) technique for friction stir welding. Post-welding, the friction stir weld (FSW) tool would be fitted with an end mill that would machine the weld smooth, trimmed shaved. This would eliminate the need for manual weld preparation for ultrasonic inspections. Manual surface preparation is a hand operation that varies widely depending on the person preparing the welds. Shaving is a process that can be automated and tightly controlled.

  4. Electron beam welding of iridium heat source capsules (United States)

    Mustaleski, Thomas M.; Yearwood, J. Cecil; Burgan, Clyde E.; Green, L. A.


    The development of the welding procedures for the production of DOP-26 iridium alloy cups for heat source encapsulation is described. All the final assembly welds were made using the electron beam welding process. The welding of the 0.13-mm weld shield required the use of computer controlled X-Y table and a run-off tab. Welding of the frit vent to the cup required that a laser weld be made to hold the frit assembly edges together for the final electron beam weld. Great care is required in tooling design and beam placement to achieve acceptable results. Unsuccessful attempts to use laser beam welding for heat shield butt weld are discussed.

  5. 75 FR 60480 - In the Matter of Certain Bulk Welding Wire Containers and Components Thereof and Welding Wire... (United States)


    ... COMMISSION In the Matter of Certain Bulk Welding Wire Containers and Components Thereof and Welding Wire... importation, or the sale within the United States after importation of certain bulk welding wire containers, components thereof, and welding wire by reason of infringement of certain claims of United States Patent Nos...

  6. TIG-dressing of High Strength Steel Butt Welded Connections. Part 1 : Weld Toe Geometry and Local Hardness

    NARCIS (Netherlands)

    Van Es, S.H.J.; Kolstein, M.H.; Pijpers, R.J.M.; Bijlaard, F.S.K.


    This paper presents the results of extensive measurements on weld toe geometry of as-welded and TIG-dressed butt welded connections in high strength steels S460, S690 and very high strength steels S890 and S1100. Descriptions of the measurement techniques and data analysis are presented. Four weld

  7. TIG-dressing of high strength steel butt welded connections - Part 1: weld toe geometry and local hardness

    NARCIS (Netherlands)

    Es, S.H.J. van; Kolstein, M.H.; Pijpers, R.J.M.; Bijlaard, F.S.K.


    This paper presents the results of extensive measurements on weld toe geometry of as-welded and TIG-dressed butt welded connections in high strength steels S460, S690 and very high strength steels S890 and S1100. Descriptions of the measurement techniques and data analysis are presented. Four weld

  8. Application of welding science to welding engineering: A lumped parameter gas metal arc welding dynamic process model

    Energy Technology Data Exchange (ETDEWEB)

    Murray, P.E.; Smartt, H.B.; Johnson, J.A. [Lockheed Martin Idaho Technologies, Idaho Falls, ID (United States)


    We develop a model of the depth of penetration of the weld pool in gas metal arc welding (GMAW) which demonstrates interaction between the arc, filler wire and weld pool. This model is motivated by the observations of Essers and Walter which suggest a relationship between droplet momentum and penetration depth. A model of gas metal arc welding was augmented to include an improved model of mass transfer and a simple model of accelerating droplets in a plasma jet to obtain the mass and momentum of impinging droplets. The force of the droplets and depth of penetration is correlated by a dimensionless linear relation used to predict weld pool depth for a range of values of arc power and contact tip to workpiece distance. Model accuracy is examined by comparing theoretical predictions and experimental measurements of the pool depth obtained from bead on plate welds of carbon steel in an argon rich shielding gas. Moreover, theoretical predictions of pool depth are compared to the results obtained from the heat conduction model due to Christensen et al. which suggest that in some cases the momentum of impinging droplets is a better indicator of the depth of the weld pool and the presence of a deep, narrow penetration.

  9. Inert-Gas Diffuser For Plasma Or Arc Welding (United States)

    Gilbert, Jeffrey L.; Spencer, Carl N.; Hosking, Timothy J.


    Inert-gas diffuser provides protective gas cover for weld bead as it cools. Follows welding torch, maintaining continuous flow of argon over newly formed joint and prevents it from oxidizing. Helps to ensure welds of consistently high quality. Devised for plasma arc keyhole welding of plates of 0.25-in. or greater thickness, also used in tungsten/inert-gas and other plasma or arc welding processes.

  10. Welding of Aluminum Alloys to Steels: An Overview (United States)


    UNCLASSIFIED 7 UNCLASSIFIED 2.1. Fusion welding methods 2.1.1. Gas metal arc (MIG) welding and tungsten inert gas ( TIG ) welding techniques...UNCLASSIFIED 8 UNCLASSIFIED Fig.3. (a) Schematic of the butt TIG welding for joining the aluminum to steel and (b) formation of the cracks at the...dissimilar metals TIG welding -brazing of aluminum alloy to stainless steel, Materials Science and Engineering A 509 (2009) 31-40. [28] S.B. Lin, J.L. Song

  11. Analysis of the Effect of Welding on SPSW Stress

    Directory of Open Access Journals (Sweden)

    Lan Tao


    Full Text Available Welding is a major connection mode of SPSW (Steel Plate Shear Wall. However, the residual stress and deformation have great influence on the SPSW bearing capacity. A sound welding sequence and a welding technology are required so as to minimize the negative effect on SPSW stress. Therefore, in this paper, Exquisite FEM is selected as the way to analyze the full welding process of SPSW. Accordingly, the basic principles of SPSW welding are discussed in this paper.

  12. Slag-metal reactions during welding: Part II. Theory (United States)

    Mitra, U.; Eagar, T. W.


    A kinetic model is developed to describe the transfer of alloying elements between the slag and the metal during flux-shielded welding. The model accounts for changes in alloy recovery based on the geometry of the resulting weld bead. It also distinguishes compositional differences between single-pass and multiple-pass weld beads. It is further shown that the final weld metal oxygen content is directly related to the weld solidification time as well as the type of flux used.

  13. Microhardness Testing of Aluminum Alloy Welds (United States)

    Bohanon, Catherine


    A weld is made when two pieces of metal are united or fused together using heat or pressure, and sometimes both. There are several different types of welds, each having their own unique properties and microstructure. Strength is a property normally used in deciding which kind of weld is suitable for a certain metal or joint. Depending on the weld process used and the heat required for that process, the weld and the heat-affected zone undergo microstructural changes resulting in stronger or weaker areas. The heat-affected zone (HAZ) is the region that has experienced enough heat to cause solid-state microstructural changes, but not enough to melt the material. This area is located between the parent material and the weld, with the grain structure growing as it progresses respectively. The optimal weld would have a short HAZ and a small fluctuation in strength from parent metal to weld. To determine the strength of the weld and decide whether it is suitable for the specific joint certain properties are looked at, among these are ultimate tensile strength, 0.2% offset yield strength and hardness. Ultimate tensile strength gives the maximum load the metal can stand while the offset yield strength gives the amount of stress the metal can take before it is 0.2% longer than it was originally. Both of these are good tests, but they both require breaking or deforming the sample in some way. Hardness testing, however, provides an objective evaluation of weld strengths, and also the difference or variation in strength across the weld and HAZ which is difficult to do with tensile testing. Hardness is the resistance to permanent or plastic deformation and can be taken at any desired point on the specimen. With hardness testing, it is possible to test from parent metal to weld and see the difference in strength as you progress from parent material to weld. Hardness around grain boundaries and flaws in the material will show how these affect the strength of the metal while still

  14. A novel weld seam detection method for space weld seam of narrow butt joint in laser welding (United States)

    Shao, Wen Jun; Huang, Yu; Zhang, Yong


    Structured light measurement is widely used for weld seam detection owing to its high measurement precision and robust. However, there is nearly no geometrical deformation of the stripe projected onto weld face, whose seam width is less than 0.1 mm and without misalignment. So, it's very difficult to ensure an exact retrieval of the seam feature. This issue is raised as laser welding for butt joint of thin metal plate is widely applied. Moreover, measurement for the seam width, seam center and the normal vector of the weld face at the same time during welding process is of great importance to the welding quality but rarely reported. Consequently, a seam measurement method based on vision sensor for space weld seam of narrow butt joint is proposed in this article. Three laser stripes with different wave length are project on the weldment, in which two red laser stripes are designed and used to measure the three dimensional profile of the weld face by the principle of optical triangulation, and the third green laser stripe is used as light source to measure the edge and the centerline of the seam by the principle of passive vision sensor. The corresponding image process algorithm is proposed to extract the centerline of the red laser stripes as well as the seam feature. All these three laser stripes are captured and processed in a single image so that the three dimensional position of the space weld seam can be obtained simultaneously. Finally, the result of experiment reveals that the proposed method can meet the precision demand of space narrow butt joint.


    Energy Technology Data Exchange (ETDEWEB)

    Korinko, P.; Howard, S.; Maxwell, D.; Fiscus, J.


    During final preparations for start of the PDCF Inner Can (IC) qualification effort, welding was performed on an automated weld system known as the PICN. During the initial weld, using a pedigree canister and plug, a weld defect was observed. The defect resulted in a hole in the sidewall of the canister, and it was observed that the plug sidewall had not been consumed. This was a new type of failure not seen during development and production of legacy Bagless Transfer Cans (FB-Line/Hanford). Therefore, a team was assembled to determine the root cause and to determine if the process could be improved. After several brain storming sessions (MS and T, R and D Engineering, PDC Project), an evaluation matrix was established to direct this effort. The matrix identified numerous activities that could be taken and then prioritized those activities. This effort was limited by both time and resources (the number of canisters and plugs available for testing was limited). A discovery process was initiated to evaluate the Vendor's IC fabrication process relative to legacy processes. There were no significant findings, however, some information regarding forging/anneal processes could not be obtained. Evaluations were conducted to compare mechanical properties of the PDC canisters relative to the legacy canisters. Some differences were identified, but mechanical properties were determined to be consistent with legacy materials. A number of process changes were also evaluated. A heat treatment procedure was established that could reduce the magnetic characteristics to levels similar to the legacy materials. An in-situ arc annealing process was developed that resulted in improved weld characteristics for test articles. Also several tack welds configurations were addressed, it was found that increasing the number of tack welds (and changing the sequence) resulted in decreased can to plug gaps and a more stable weld for test articles. Incorporating all of the process

  16. Influence of the Gap Width on the Geometry of the Welded Joint in Hybrid Laser-Arc Welding (United States)

    Turichin, G.; Tsibulskiy, I.; Kuznetsov, M.; Akhmetov, A.; Mildebrath, M.; Hassel, T.

    The aim of this research was the experimental investigation of the influence of the gap width and speed of the welding wire on the changes of the geometry in the welded joint in the hybrid laser-arc welding of shipbuilding steel RS E36. The research was divided into three parts. First, in order to understand the influence of the gap width on the welded joint geometry, experimental research was done using continuous wave fiber laser IPG YLS-15000 with arc rectifier VDU-1500DC. The second part involved study of the geometry of the welded joint and hardness test results. Three macrosections from each welded joint were obtained. Influence of the gap width and welding wire speed on the welded joint geometry was researched in the three lines: in the right side of the plates, middle welded joint and in the root welded joint.

  17. Braze welding of cobalt with a silver–copper filler

    Directory of Open Access Journals (Sweden)

    Everett M. Criss


    Full Text Available A new method of joining cobalt by braze-welding it with a silver–copper filler was developed in order to better understand the residual stresses in beryllium–aluminum/silicon weldments which are problematic to investigate because of the high toxicity of Be. The base and filler metals of this new welding system were selected to replicate the physical properties, crystal structures, and chemical behavior of the Be–AlSi welds. Welding parameters of this surrogate Co–AgCu system were determined by experimentation combining 4-point bending tests and microscopy. Final welds are 5 pass manual TIG (tungsten inert gas, with He top gas and Ar back gas. Control of the welding process produces welds with full penetration melting of the cobalt base. Microscopy indicates that cracking is minimal, and not through thickness, whereas 4-point bending shows failure is not by base-filler delamination. These welds improve upon the original Be–AlSi welds, which do not possess full penetration, and have considerable porosity. We propose that utilization of our welding methods will increase the strength of the Be–AlSi weldments. The specialized welding techniques developed for this study may be applicable not only for the parent Be–AlSi welds, but to braze welds and welds utilizing brittle materials in general. This concept of surrogacy may prove useful in the study of many different types of exotic welds.

  18. Tool For Friction Stir Tack Welding of Aluminum Alloys (United States)

    Bjorkman, Gerald W.; Dingler, Johnny W.; Loftus, Zachary


    A small friction-stir-welding tool has been developed for use in tack welding of aluminum-alloy workpieces. It is necessary to tack-weld the workpieces in order to hold them together during friction stir welding because (1) in operation, a full-size friction-stir-welding tool exerts a large force that tends to separate the workpieces and (2) clamping the workpieces is not sufficient to resist this force. It is possible to tack the pieces together by gas tungsten arc welding, but the process can be awkward and time-consuming and can cause sufficient damage to necessitate rework. Friction stir tack welding does not entail these disadvantages. In addition, friction stir tack welding can be accomplished by use of the same automated equipment (except for the welding tool) used in subsequent full friction stir welding. The tool for friction stir tack welding resembles the tool for full friction stir welding, but has a narrower shoulder and a shorter pin. The shorter pin generates a smaller workpiece-separating force so that clamping suffices to keep the workpieces together. This tool produces a continuous or intermittent partial-penetration tack weld. The tack weld is subsequently consumed by action of the larger tool used in full friction stir welding tool.

  19. Hot cracking during laser welding of steel: influence of the welding parameters and prevention of cracks (United States)

    Schaefer, Marcel; Kessler, Steffen; Scheible, Philipp; Speker, Nicolai; Harrer, Thomas


    In continuous wave keyhole-mode laser welding of high strength steel alloys hot cracking can occur. The hot crack susceptibility depends on the mutual interaction of several factors like the welding parameters, the alloy composition and the weld fixturing. In this paper we focus on the influence of the welding parameters and investigate the dependency of the laser power, the welding speed and the laser wavelength on the crack formation. X-ray images are used to visualize the hot crack patterns, which exhibit a pronounced periodicity. To influence the hot crack formation, the incident energy input into the process was adapted. For specific welding parameters, we show exemplarily the prevention of hot cracking by the use of a twin-spot optics.

  20. On post-weld heat treatment cracking in tig welded superalloy ATI 718Plus

    Directory of Open Access Journals (Sweden)

    G. Asala


    Full Text Available The susceptibility of heat affected zone (HAZ to cracking in Tungsten Inert Gas (TIG welded Allvac 718Plus superalloy during post-weld heat treatment (PWHT was studied. Contrary to the previously reported case of low heat input electron beam welded Allvac 718Plus, where HAZ cracking occurred during PWHT, the TIG welded alloy is crack-free after PWHT, notwithstanding the presence of similar micro-constituents that caused cracking in the low input weld. Accordingly, the formation of brittle HAZ intergranular micro-constituents may not be a sufficient factor to determine cracking propensity, the extent of heat input during welding may be another major factor that influences HAZ cracking during PWHT of the aerospace superalloy Allvac 718Plus.

  1. On post-weld heat treatment cracking in tig welded superalloy ATI 718Plus (United States)

    Asala, G.; Ojo, O. A.

    The susceptibility of heat affected zone (HAZ) to cracking in Tungsten Inert Gas (TIG) welded Allvac 718Plus superalloy during post-weld heat treatment (PWHT) was studied. Contrary to the previously reported case of low heat input electron beam welded Allvac 718Plus, where HAZ cracking occurred during PWHT, the TIG welded alloy is crack-free after PWHT, notwithstanding the presence of similar micro-constituents that caused cracking in the low input weld. Accordingly, the formation of brittle HAZ intergranular micro-constituents may not be a sufficient factor to determine cracking propensity, the extent of heat input during welding may be another major factor that influences HAZ cracking during PWHT of the aerospace superalloy Allvac 718Plus.

  2. Corrosion resistance of «tube – tubesheet» weld joint obtained by friction welding

    Directory of Open Access Journals (Sweden)

    RIZVANOV Rif Garifovich


    Full Text Available Shell-and-tube heat exchangers are widely applied for implementation of various processes at ventures of fuel and energy complex. Cost of production and reliability of heat exchangers of this type is to a wide extent determined by corresponding characteristics of tube bundle, «tube – tubesheet» is its typical joint in particular when welding operations are used in order to attach tubes to tubesheet in addition to expansion. When manufacturing such equipment of heat-resistant chrome-bearing or chromium-molybdenum steels including steel 15H5M, the process of fixed joint manufacturing gets significantly more complicated and costly due to the necessity to use thermal treatment before, during and after welding (this problem is particularly applicable for manufacturing of large-size equipment. One of the options to exclude thermal treatment from manufacturing process is to use «non-arc» welding methods – laser welding, explosion welding as well as friction welding. Use of each of the welding methods mentioned above during production of heat-exchange equipment has its process challenges and peculiarities. This article gives a comparative analysis of weld structure and distribution of electrode potentials of welded joints and parent metal of the joints simulating welding of tube to tubesheet of steel 15H5M using the following welding methods: shielded manual arc welding, tungsten-arc inert-gas welding and friction welding. Comparative analysis of macro- and microstructures of specific zones of the studied welded joints showed that the joints produced by arc welding methods do not exhibit evident inhomogeneity of the structure after application of thermal treatment which is explained by the correctness of thermal treatment. Joints obtained via friction welding are characterized by structural inhomogeneity of the welded joint zone metal microstructure. The ultra-fine-grained structure obtained as a result of friction welding makes it possible to

  3. The use of welding techniques in protection of welding structures against corrosion

    Directory of Open Access Journals (Sweden)

    J.St. Kowalski


    Full Text Available The paper presents possibilities of using welding techniques as a means of protection from corrosion of materials for welding structuresoperating in power engineering industry, chemical industry and shipbuilding. Based on the example of an LNG installation, the potentials of weld overlaying in anti-corrosive protection of parts operating in LNG installations have been described. The weld overlaying technique enables building up of protective coatings, which not only protect material from corrosion resulting from the flow of more or less aggressive medium (e.g. water, exhaust gas but also increase the performance life of thus “coated” elements due to the improved abrasion wear resistance of weld overlays. The weld overlaying process is equally well suitable in building of new structures as in the repair of damaged or worn out elements of water or power feeding installations.

  4. An Evaluation of Welding Processes to Reduce Hexavalent Chromium Exposures and Reduce Costs by Using Better Welding Techniques


    Keane, Michael J


    A group of stainless steel arc welding processes was compared for emission rates of fume and hexavalent chromium, and costs per meter length of weld. The objective was to identify those with minimal emissions and also compare relative labor and consumables costs. The selection included flux-cored arc welding (FCAW), shielded-metal arc welding (SMAW), and multiple gas metal arc welding (GMAW) processes. Using a conical chamber, fumes were collected, and fume generation rates and hexavalent chr...

  5. Effects of laser offset and hybrid welding on microstructure and IMC in Fe–Al dissimilar welding


    Casalino, Giuseppe; Leo, Paola; Mortello, Michelangelo; Perulli, Patrizia; Varone, Alessandra


    Welding between Fe and Al alloys is difficult because of a significant difference in thermal properties and poor mutual solid-state solubility. This affects the weld microstructure and causes the formation of brittle intermetallic compounds (IMCs). The present study aims to explore the weld microstructure and those compounds over two different technologies: the laser offset welding and the hybrid laser-MIG (Metal inert gas) welding. The former consists of focusing the laser beam on the top su...

  6. Simulation of Weld Mechanical Behavior to Include Welding-Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes (United States)


    2011, Vol. 88, pg. 45-56. 7. Z.H. Guo, X.Y. Ou, G.W. Shuai, and Y.H. Chen, Numerical Simulation of Temperature Field for TIG Welding of Aluminum Alloy...Memorandum Simulation of Weld Mechanical Behavior to Include Welding -Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes... Weld Mechanical Behavior to Include Welding -Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes by Charles R. Fisher

  7. Advantages of MAG-STT Welding Process for Root Pass Welding in the Oil and Gas Industry

    Directory of Open Access Journals (Sweden)

    Pandzic Adi


    Full Text Available This paper describesthe basics of modern MAG-STT welding process and its advantages for root pass welding of construction steels in oil and gas industry. MAG-STT welding process was compared with competitive arc welding processes (SMAW and TIG, which are also used for root pass welding on pipes and plates. After experimental tests, the obtained results are analyzed and presented in this paper

  8. Simulation of Weld Mechanical Behavior to Include Welding Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes (United States)


    2011, Vol. 88, pg. 45-56. 7. Z.H. Guo, X.Y. Ou, G.W. Shuai, and Y.H. Chen, Numerical Simulation of Temperature Field for TIG Welding of Aluminum Alloy...Memorandum Simulation of Weld Mechanical Behavior to Include Welding -Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes... Weld Mechanical Behavior to Include Welding -Induced Residual Stress and Distortion: Coupling of SYSWELD and Abaqus Codes by Charles R. Fisher

  9. Laser micro welding of copper and aluminum (United States)

    Mys, Ihor; Schmidt, Michael


    Aluminum combines comparably good thermal and electrical properties with a low price and a low material weight. These properties make aluminum a promising alternative to copper for a large number of electronic applications, especially when manufacturing high volume components. However, a main obstacle for a wide use of this material is the lack of a reliable joining process for the interconnection of copper and aluminum. The reasons for this are a large misalignment in the physical properties and even more a poor metallurgical affinity of both materials that cause high crack sensitivity and the formation of brittle intermetallic phases during fusion welding. This paper presents investigations on laser micro welding of copper and aluminum with the objective to eliminate brittle intermetallic phases in the welding structure. For these purposes a combination of spot welding, a proper beam offset and special filler material are applied. The effect of silver, nickel and tin filler materials in the form of thin foils and coatings in a thickness range 3-100 μm has been investigated. Use of silver and tin filler materials yields to a considerable improvement of the static and dynamic mechanical stability of welded joints. The analysis of the weld microstructure shows that an application even of small amounts of suitable filler materials helps to avoid critical, very brittle intermetallic phases on the interface between copper and solidified melt in the welded joints.

  10. Automated generation of weld path trajectories.

    Energy Technology Data Exchange (ETDEWEB)

    Sizemore, John M. (Northrop Grumman Ship Systems); Hinman-Sweeney, Elaine Marie; Ames, Arlo Leroy


    AUTOmated GENeration of Control Programs for Robotic Welding of Ship Structure (AUTOGEN) is software that automates the planning and compiling of control programs for robotic welding of ship structure. The software works by evaluating computer representations of the ship design and the manufacturing plan. Based on this evaluation, AUTOGEN internally identifies and appropriately characterizes each weld. Then it constructs the robot motions necessary to accomplish the welds and determines for each the correct assignment of process control values. AUTOGEN generates these robot control programs completely without manual intervention or edits except to correct wrong or missing input data. Most ship structure assemblies are unique or at best manufactured only a few times. Accordingly, the high cost inherent in all previous methods of preparing complex control programs has made robot welding of ship structures economically unattractive to the U.S. shipbuilding industry. AUTOGEN eliminates the cost of creating robot control programs. With programming costs eliminated, capitalization of robots to weld ship structures becomes economically viable. Robot welding of ship structures will result in reduced ship costs, uniform product quality, and enhanced worker safety. Sandia National Laboratories and Northrop Grumman Ship Systems worked with the National Shipbuilding Research Program to develop a means of automated path and process generation for robotic welding. This effort resulted in the AUTOGEN program, which has successfully demonstrated automated path generation and robot control. Although the current implementation of AUTOGEN is optimized for welding applications, the path and process planning capability has applicability to a number of industrial applications, including painting, riveting, and adhesive delivery.

  11. Corrosion fatigue behaviour of aluminium 5083-H111 welded using gas metal arc welding method

    CSIR Research Space (South Africa)

    Mutombo, K


    Full Text Available susceptible to hydrogen-induced porosity. The weld pool may dissolve large amount of hydrogen from the arc atmosphere. On solidification, the solubility of hydrogen decreases and the entrapped hydrogen forms gas porosity. Typical sources of hydrogen... Behaviour of Aluminium 5083-H111 Welded Using Gas Metal Arc Welding Method Kalenda Mutombo1 and Madeleine du Toit2 1CSIR/ 2University of Pretoria South Africa 1. Introduction Aluminium and its alloys are widely used as engineering materials...

  12. Heat sink effects in VPPA welding (United States)

    Steranka, Paul O., Jr.


    The development of a model for prediction of heat sink effects associated with the Variable Polarity Plasma Arc (VPPA) Welding Process is discussed. The long term goal of this modeling is to provide means for assessing potential heat sink effects and, eventually, to provide indications as to changes in the welding process that could be used to compensate for these effects and maintain the desired weld quality. In addition to the development of a theoretical model, a brief experimental investigation was conducted to demonstrate heat sink effects and to provide an indication of the accuracy of the model.

  13. Analysis and Comparison of Friction Stir Welding and Laser Assisted Friction Stir Welding of Aluminum Alloy. (United States)

    Campanelli, Sabina Luisa; Casalino, Giuseppe; Casavola, Caterina; Moramarco, Vincenzo


    Friction Stir Welding (FSW) is a solid-state joining process; i.e. , no melting occurs. The welding process is promoted by the rotation and translation of an axis-symmetric non-consumable tool along the weld centerline. Thus, the FSW process is performed at much lower temperatures than conventional fusion welding, nevertheless it has some disadvantages. Laser Assisted Friction Stir Welding (LAFSW) is a combination in which the FSW is the dominant welding process and the laser pre-heats the weld. In this work FSW and LAFSW tests were conducted on 6 mm thick 5754H111 aluminum alloy plates in butt joint configuration. LAFSW is studied firstly to demonstrate the weldability of aluminum alloy using that technique. Secondly, process parameters, such as laser power and temperature gradient are investigated in order to evaluate changes in microstructure, micro-hardness, residual stress, and tensile properties. Once the possibility to achieve sound weld using LAFSW is demonstrated, it will be possible to explore the benefits for tool wear, higher welding speeds, and lower clamping force.

  14. Characteristics comparison of weld metal zones welded to cast and forged steels for piston crown material (United States)

    Moon, Kyung-Man; Kim, Yun-Hae; Lee, Myeong-Hoon; Baek, Tae-Sil


    An optimum repair welding for the piston crown which is one of the engine parts exposed to the combustion chamber is considered to be very important to prolong the engine lifetime from an economical point of view. In this study, two types of filler metals such as 1.25Cr-0.5Mo, 0.5Mo were welded with SMAW method and the other two types of filler metals such as Inconel 625 and 718 were welded with GTAW method, respectively, and the used base metals were the cast and forged steels of the piston crown material. The weld metal zones welded with Inconel 625 and 718 filler metals exhibited higher corrosion resistance compared to 1.25Cr-0.5Mo and 0.5Mo filler metals. In particular, the weld metal zone welded with Inconel 718 and 0.5Mo, filler metals indicated the best and worst corrosion resistance, respectively. Consequently, it is suggested that the corrosion resistance of the weld metal zone surely depends on the chemical components of each filler metal and welding method irrespective of the types of piston crown material.

  15. Weld microstructure and hardness prediction for in-service hot-tap welds

    Energy Technology Data Exchange (ETDEWEB)

    Wentao Cheng; Yong-Yi Wang [Engineering Mechanics Corporation of Columbus, OH (United States)]. E-mail:;; Amend, William [Southern California Gas Co., Los Angeles, CA (United States)]. E-mail:


    Welding onto an in-service pipeline is frequently required to repair damaged areas and for system modifications. There are often significant economic and environmental incentives to perform in-service welding, including the ability to maintain operations during welding and to avoid venting the contents to the atmosphere. Welds made onto in-service pipelines tend to cool at an accelerated rate. These welds are likely to have high heat-affected zone (HAZ) hardness which increases their susceptibility to hydrogen cracking. Accurate prediction of HAZ hardness is critical in developing successful welding procedures for in-service hot-tap welds. The present PRCI thermal analysis software for hot-tap welding uses an empirical-formula-based HAZ hardness prediction procedure. This paper describes an effort funded by PRCI to produce a significantly improved HAZ hardness prediction procedure over the procedure in the current PRCI thermal analysis software. A markedly improved hardness prediction procedure was developed and systematically validated using extensive experimental data of actual welds. The underlying hardness calculation algorithms were based on the proven state-of-the-art phase transformation models. Although on the average the procedure under-predicts the measured hardness by a small amount, the new hardness prediction procedure is a significant improvement in overall accuracy over the procedure in the current PRCI thermal analysis software. The procedure developed here lays the foundation for a much more accurate hardness prediction module in the future version of the PRCI thermal analysis software. (author)

  16. Application of TRIZ Methodology in Diffusion Welding System Optimization (United States)

    Ravinder Reddy, N.; Satyanarayana, V. V.; Prashanthi, M.; Suguna, N.


    Welding is tremendously used in metal joining processes in the manufacturing process. In recent years, diffusion welding method has significantly increased the quality of a weld. Nevertheless, diffusion welding has some extent short research and application progress. Therefore, diffusion welding has a lack of relevant information, concerned with the joining of thick and thin materials with or without interlayers, on welding design such as fixture, parameters selection and integrated design. This article intends to combine innovative methods in the application of diffusion welding design. This will help to decrease trial and error or failure risks in the welding process being guided by the theory of inventive problem solving (TRIZ) design method. This article hopes to provide welding design personnel with innovative design ideas under research and for practical application.


    Directory of Open Access Journals (Sweden)

    Ján Viňáš


    Full Text Available The contribution deals with the influence of welding electrode tips deformation on their lifetime. The influence of material properties, production technology and the intensity of welding electrodes load on their lifetime are presented. The electrode tips of the most used type of CuCr1Zr alloy of three basic standard shapes before and after the process of welding are evaluated. The process of welding is realized with low, middle and maximum welding parameters on programmable pneumatic spot welding machine VTS BPK 20. The influence of welding parameters on chosen material characteristics of welding tips is observed. Through the use of upsetting test, dependency of forming strength and deformation of material on used technology of welding tip production is observed.


    Directory of Open Access Journals (Sweden)

    Afshin Kheidari Monfared


    Full Text Available Welding is a crucial manufacturing process and widely used for manufacturing various products including ships, automobiles, trains and bridges. Welding distortions often occur in welded structures of thin plates due to relatively low stiffness and result in their warpage during assembly process and high manufacturing cost. Therefore, prediction and reduction of welding distortions are important in order to improve quality of welded structures. Welding distortion during the assembly process is caused not only by local shrinkage due to rapid heating and cooling. 3-D thermo-elastic-plastic finite element method (FEM has been used to simulate single-bead-on-plate welding with 1 mm thickness. Experiments have been carried out to prove the simulated results. Comparison of the experimental results and FEM simulation results has confirmed that the proposed method efficiently  predicts level of  welding distortions while making single-bead-on-plate welding with 1 mm thickness.

  19. Method for defect free keyhole plasma arc welding (United States)

    Harwig, Dennis D. (Inventor); Hunt, James F. (Inventor); Ryan, Patrick M. (Inventor); Fisher, Walter J. (Inventor)


    A plasma arc welding process for welding metal of increased thickness with one pass includes operating the plasma arc welding apparatus at a selected plasma gas flow rate, travel speed and arc current, to form a weld having a penetration ratio to weld height to weld width, and maintaining the penetration ratio at less than 0.74. Parameters for the plasma gas flow rate, travel speed and arc current are adjusted to a steady state condition during a start up period and maintained during the steady state condition to complete a weld. During a terminal stopping period, the travel speed is stopped and instantaneously replaced by filler wire which adds material to fill the keyhole that had been formed by the welding process. Parameters are subsequently adjusted during the stopping period to terminate the weld in a sound manner.

  20. Fatique Resistant, Energy Efficient Welding Program, Final Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Egland, Keith; Ludewig, Howard


    The program scope was to affect the heat input and the resultant weld bead geometry by synchronizing robotic weave cycles with desired pulsed waveform shapes to develop process parameters relationships and optimized pulsed gas metal arc welding processes for welding fatique-critical structures of steel, high strength steel, and aluminum. Quality would be addressed by developing intelligent methods of weld measurement that accurately predict weld bead geometry from process information. This program was severely underfunded, and eventually terminated. The scope was redirected to investigate tandem narrow groove welding of steel butt joints during the one year of partial funding. A torch was designed and configured to perform a design of experiments of steel butt weld joints that validated the feasability of the process. An initial cost model estimated a 60% cost savings over conventional groove welding by eliminating the joint preparation and reducing the weld volume needed.


    Directory of Open Access Journals (Sweden)



    Full Text Available Welding is tremendously used in metal joining processes in the manufacturing process. In recent years, diffusion welding method has significantly increased the quality of a weld. Nevertheless, diffusion welding has some extent short research and application progress. Therefore, diffusion welding has a lack of relevant information, concerned with the joining of thick and thin materials with or without interlayers, on welding design such as fixture, parameters selection and inte-grated design. This article intends to combine innovative methods in the application of diffusion welding design. This will help to decrease trial and error or failure risks in the welding process being guided by the theory of inventive problem solving (TRIZ design method. This article hopes to provide welding design personnel with innovative design ideas under research and for practical application.

  2. Pulsed Magnetic Welding for Advanced Core and Cladding Steel

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Guoping [Univ. of Wisconsin, Madison, WI (United States); Yang, Yong [Univ. of Florida, Gainesville, FL (United States)


    To investigate a solid-state joining method, pulsed magnetic welding (PMW), for welding the advanced core and cladding steels to be used in Generation IV systems, with a specific application for fuel pin end-plug welding. As another alternative solid state welding technique, pulsed magnetic welding (PMW) has not been extensively explored on the advanced steels. The resultant weld can be free from microstructure defects (pores, non-metallic inclusions, segregation of alloying elements). More specifically, the following objectives are to be achieved: 1. To design a suitable welding apparatus fixture, and optimize welding parameters for repeatable and acceptable joining of the fuel pin end-plug. The welding will be evaluated using tensile tests for lap joint weldments and helium leak tests for the fuel pin end-plug; 2 Investigate the microstructural and mechanical properties changes in PMW weldments of proposed advanced core and cladding alloys; 3. Simulate the irradiation effects on the PWM weldments using ion irradiation.

  3. Mechanical Properties of Welded Deformed Reinforcing Steel Bars

    Directory of Open Access Journals (Sweden)

    Ghafur H. Ahmed


    Full Text Available Reinforcement strength, ductility and bendability properties are important components in design of reinforced concrete members, as the strength of any member comes mainly from reinforcement. Strain compatibility and plastic behaviors are mainly depending on reinforcement ductility. In construction practice, often welding of the bars is required. Welding of reinforcement is an instant solution in many cases, whereas welding is not a routine connection process. Welding will cause deficiencies in reinforcement bars, metallurgical changes and re-crystallization of microstructure of particles. Weld metal toughness is extremely sensitive to the welding heat input that decreases both of its strength and ductility. For determining the effects of welding in reinforcement properties, 48 specimens were tested with 5 different bar diameters, divided into six groups. Investigated parameters were: properties of un-welded bars; strength, ductility and density of weld metal; strength and ductility reduction due to heat input for bundled bars and transverse bars; welding effect on bars’ bending properties; behavior of different joint types; properties of three weld groove shapes also the locations and types of failures sections. Results show that, strength and elongation of the welded bars decreased by (10-40% and (30-60% respectively. Cold bending of welded bars and groove welds shall be prevented.

  4. Electron Beam Welding of Gear Wheels by Splitted Beam (United States)

    Dřímal, Daniel


    This contribution deals with the issue of electron beam welding of high-accurate gear wheels composed of a spur gearing and fluted shaft joined with a face weld for automotive industry. Both parts made of the high-strength low-alloy steel are welded in the condition after final machining and heat treatment, performed by case hardening, whereas it is required that the run-out in the critical point of weldment after welding, i. e. after the final operation, would be 0.04 mm max.. In case of common welding procedure, cracks were formed in the weld, initiated by spiking in the weld root. Crack formation was prevented by the use of an interlocking joint with a rounded recess and suitable welding parameters, eliminating crack initiation by spiking in the weld root. Minimisation of the welding distortions was achieved by the application of tack welding with simultaneous splitting of one beam into two parts in the opposite sections of circumferential face weld attained on the principle of a new system of controlled deflection with digital scanning of the beam. This welding procedure assured that the weldment temperature after welding would not be higher than 400 °C. Thus, this procedure allowed achieving the final run-outs in the critical point of gearwheels within the maximum range up to 0.04 mm, which is acceptable for the given application. Accurate optical measurements did not reveal any changes in the teeth dimensions.

  5. The characteristics of welded joints for air conditioning application (United States)

    Weglowski, M. St.; Weglowska, A.; Miara, D.; Kwiecinski, K.; Błacha, S.; Dworak, J.; Rykala, J.; Pikula, J.; Ziobro, G.; Szafron, A.; Zimierska-Nowak, P.; Richert, M.; Noga, P.


    In the paper the results of metallographic examination of welded joints for air-conditioning elements are presented. The European directives 2006/40/EC on the greenhouse gasses elimination demand to stop using traditional refrigerant and to change it to R744 (CO2) medium in air conditioning installation. The R744 refrigerant is environmental friendly medium if compared with standard solution such as R12, R134a or R1234yf and safer for passengers than R1234yf. The non-standard thermodynamic parameters of the R744 which translate into high pressure and high temperature require specific materials to develop the shape and to specify the technology of manufacturing for the particular elements of the conduits and moreover the technologies of joining for the whole structure, which would meet the exploitation requirements of the new air-conditioning system. To produce the test welded joints of stainless steels four different joining technologies were applied: laser welding, plasma welding, electron beam welding as well as high speed rotation welding. This paper describes the influence of the selected welding process on the macrostructure and microstructure of welded joints of AISI 304 and AISI 316L steels. The results indicated that plasma welding laser welding and electron beam welding technologies guaranty the proper quality of welded joints and can be used for the air conditioning application in automotive industry. However, high speed rotation welding not guarantee the good quality of welded joints and cannot be used for above application.

  6. Study on the effect of post weld heat treatment parameters on the relaxation of welding residual stresses in electron beam welded P91 steel plates


    Venkata, K. Abburi; Kumar, S.; Dey, H.C.; Smith, D. J.; Bouchard, P J; Truman, C.E


    Residual stresses are created by localised heating effects that occur during the welding process. Post weld heat treatment (PWHT) is the most convenient method for stress relief of welds. But PWHT cannot completely eliminate the residual stresses. So, it is essential to determine the influence of PWHT parameters like holding temperature and time on the stress relaxation for optimising the process. The selected material is modified 9Cr-1Mo (Grade 91) steel in the form of plates welded together...

  7. [Study on the arc spectral information for welding quality diagnosis]. (United States)

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


    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.

  8. Bringing Pulsed Laser Welding into Production

    DEFF Research Database (Denmark)

    Olsen, Flemmming Ove


    In this paper, some research and develop-ment activities within pulsed laser welding technology at the Tech-nical University of Denmark will be described. The laser group at the Insti-tute for Manufacturing Technology has nearly 20 years of experience in laser materials process-ing. Inter......-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...... activities concerning the weldability of high alloyed austenitic stainless steels for mass production industry applying industrial lasers for fine welding will be described. Studies on hot cracking sensitivity of high alloyed austenitic stainless steel applying both ND-YAG-lasers and CO2-lasers has been...

  9. Torque Control of Friction Stir Welding Project (United States)

    National Aeronautics and Space Administration — Longhurst Engineering, PLC and Vanderbilt University propose the innovation of torque control of friction stir welding (FSW) as a replacement to force control of...

  10. Vibration welding system with thin film sensor (United States)

    Cai, Wayne W; Abell, Jeffrey A; Li, Xiaochun; Choi, Hongseok; Zhao, Jingzhou


    A vibration welding system includes an anvil, a welding horn, a thin film sensor, and a process controller. The anvil and horn include working surfaces that contact a work piece during the welding process. The sensor measures a control value at the working surface. The measured control value is transmitted to the controller, which controls the system in part using the measured control value. The thin film sensor may include a plurality of thermopiles and thermocouples which collectively measure temperature and heat flux at the working surface. A method includes providing a welder device with a slot adjacent to a working surface of the welder device, inserting the thin film sensor into the slot, and using the sensor to measure a control value at the working surface. A process controller then controls the vibration welding system in part using the measured control value.

  11. Plasma Arc Augmented CO2 laser welding

    DEFF Research Database (Denmark)

    Bagger, Claus; Andersen, Mikkel; Frederiksen, Niels


    In order to reduce the hardness of laser beam welded 2.13 mm medium strength steel CMn 250, a plasma arc has been used simultaneously with a 2.6 kW CO2 laser source. In a number of systematic laboratory tests, the plasma arc current, plasma gas flow and distance to the laser source were varied...... with all laser parameters fixed. The welds were quality assessed and hardness measured transversely to the welding direction in the top, middle and root of the seam. In the seams welded by laser alone, hardness values between 275 and 304 HV1 were measured, about the double of the base material, 150 HV1...

  12. Microsoldering and microminiature welding with lasers

    Energy Technology Data Exchange (ETDEWEB)

    Jellison, J.L.; Keicher, D.M.


    Miniature welding of electronic and electromechanical components with lasers is a rapidly maturing technology. Extending the use of lasers to microsoldering and microminiature welding applications has also generated moderate interest. Use of lasers for microminiature soldering or welding permits the delivery of accurately controlled amounts of heat to the precise area required. By applying small amounts of heat locally, rework can be accomplished in densely packed circuits without damaging heat sensitive components to conductors. Also, localization of heat obviates the need for using solder alloys of different melting points, which can simplify design. Laser soldering has been applied to conductors ranging from 25 dia. wires to coaxial cables in the 0.3 to 1.25 mm range. For the most part, these conductors were soldered to metallized alumina substrates, although in some instances soft substrates were also used. The potential advantages of microminiature welding have also been explored. 9 refs., 6 figs., 1 tab.

  13. The influence of the weld toe grinding and wig remelting weld toe rehabilitation techniques, on variable stresses, in case of cross fillet welds, reinforced with additional welding rows

    Directory of Open Access Journals (Sweden)

    Babis Claudiu


    Full Text Available Variable stresses where the load value varies between a maximum and a minimum value, or varies the position in time, cause after accumulating a large number of load cycles in those structures, the emergence of drug fatigue. Fatigue is characterized by failure on values of the applied stress from the load cycles, below the material flow, values which in case of static stress would not have caused problems. Knowing that the variable stressed structures are sensitive to stress concentrators, the paper aims to highlight the influence of two techniques to reduce stress concentrator weld toe grinding and WIG remelting weld toe, on the behavior of variable tensile test of cross corner welded specimens, reinforced with additional welding rows.

  14. Metal Flow in Friction Stir Welding (United States)

    Nunes, Arthur C., Jr.


    The plastic deformation field in Friction Stir Welding (FSW) is compared to that in metal cutting. A shear surface around the FSW tool analogous to the metal cutting shear plane is identified and comprises the basis of the "rotating plug" flow field model and the "wiping" model of tool interaction with weld metal. Within the context of these models: The FSW shear rate is estimated to be comparable to metal cutting shear rates. The effect of tool geometry on the FSW shear surface is discussed and related to published torque measurements. Various FS W structural features are explained, including a difference in structure of bimetallic welds when alloys on the advancing and retreating sides of the weld seam are exchanged. The joining mechanism and critical parameters of the FSW process are made clear.

  15. Automatic weld torch guidance control system (United States)

    Smaith, H. E.; Wall, W. A.; Burns, M. R., Jr.


    A highly reliable, fully digital, closed circuit television optical, type automatic weld seam tracking control system was developed. This automatic tracking equipment is used to reduce weld tooling costs and increase overall automatic welding reliability. The system utilizes a charge injection device digital camera which as 60,512 inidividual pixels as the light sensing elements. Through conventional scanning means, each pixel in the focal plane is sequentially scanned, the light level signal digitized, and an 8-bit word transmitted to scratch pad memory. From memory, the microprocessor performs an analysis of the digital signal and computes the tracking error. Lastly, the corrective signal is transmitted to a cross seam actuator digital drive motor controller to complete the closed loop, feedback, tracking system. This weld seam tracking control system is capable of a tracking accuracy of + or - 0.2 mm, or better. As configured, the system is applicable to square butt, V-groove, and lap joint weldments.

  16. Material Protection During Electron-Beam Welding (United States)

    Tomlinson, R. L.; Kiluk, F. J.


    Alumina pellets behind electron-beam weld joint protect other parts of assembly from beam and from spattered material. Alumina pellets may be cleaned and reused. Easily applied and removed in regions that are narrow or have complex shapes.

  17. Electron beam welding complex diagnostics automated system

    Directory of Open Access Journals (Sweden)

    Є. В. Нікітенко


    Full Text Available The structure of the system of technical diagnostics is investigated. The algorithm of technical diagnostic of electron beam welding complex, which serves as the basis for creation of automated system for technical diagnostics, is proposed

  18. 30 CFR 250.110 - What must I include in my welding plan? (United States)


    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What must I include in my welding plan? 250.110... must I include in my welding plan? You must include all of the following in the Welding Plan that you... qualified personnel weld; (c) Practices and procedures for safe welding that address: (1) Welding in...

  19. Trends in Development of Weld Overlaying During The 21ST Century

    Directory of Open Access Journals (Sweden)

    Nikolov Mitko


    Full Text Available The present article discusses the trends in the development of welding and weld overlaying on the threshold of the new millennium and during it. It presents the trends in the production of welding materials for welding and weld overlaying in industrially developed and developing countries. The structure of welding methods is also shown, giving priority to its development until 2020.

  20. Physicochemical and toxicological characteristics of welding fume derived particles generated from real time welding processes. (United States)

    Chang, Cali; Demokritou, Philip; Shafer, Martin; Christiani, David


    Welding fume particles have been well studied in the past; however, most studies have examined welding fumes generated from machine models rather than actual exposures. Furthermore, the link between physicochemical and toxicological properties of welding fume particles has not been well understood. This study aims to investigate the physicochemical properties of particles derived during real time welding processes generated during actual welding processes and to assess the particle size specific toxicological properties. A compact cascade impactor (Harvard CCI) was stationed within the welding booth to sample particles by size. Size fractionated particles were extracted and used for both off-line physicochemical analysis and in vitro cellular toxicological characterization. Each size fraction was analyzed for ions, elemental compositions, and mass concentration. Furthermore, real time optical particle monitors (DustTrak™, TSI Inc., Shoreview, Minn.) were used in the same welding booth to collect real time PM2.5 particle number concentration data. The sampled particles were extracted from the polyurethane foam (PUF) impaction substrates using a previously developed and validated protocol, and used in a cellular assay to assess oxidative stress. By mass, welding aerosols were found to be in coarse (PM 2.5–10), and fine (PM 0.1–2.5) size ranges. Most of the water soluble (WS) metals presented higher concentrations in the coarse size range with some exceptions such as sodium, which presented elevated concentration in the PM 0.1 size range. In vitro data showed size specific dependency, with the fine and ultrafine size ranges having the highest reactive oxygen species (ROS) activity. Additionally, this study suggests a possible correlation between welders' experience, the welding procedure and equipment used and particles generated from welding fumes. Mass concentrations and total metal and water soluble metal concentrations of welding fume particles may be